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Clinical Neuroscience

JANUARY 25, 2013

[Blood lipid peroxidation, antioxidant enzyme activities and hemorheological changes in autistic children]

LÁSZLÓ Aranka, NOVÁK Zoltán, SZÕLLÕSI-VARGA Ilona, HAI Quai Du, VETRÓ Ágnes, KOVÁCS Attila

[Objectives - Early infantile autism is a severe form of childhood psychiatric disease with characteristic symptoms. Hyperserotoninaemia in 43.5%, lactic acidosis 43% and hyperpyruvataemia in 30% were biochemically demonstrated in autistic children. Our earlier results led to the postulation that a disequilibrium in the blood redox is involved in infantile autism; the oxidative loading and the antioxidant defending enzyme system were investigated together with the hemorheological parameters in infantile autism. Methods - Malonyl-dialdehyde (MDA) endproduct of lipid peroxidation and activities of the antioxidant enzymes: superoxide dismutase (SOD), catalase (C-ase), glutathione peroxidase (GP-ase) and reduced glutathione (GSH) were biochemically determined from plasma and red blood cells. Patients - The antioxidant specificities were investigated in plasma and red blood cell haemolysate from 25 infantile autistic children. Results - Significantly increased superoxide dismutase (SOD) (2.89 vs. 1.32 U/mg protein, p<0.01) and decreased glutathione peroxidase (0.620 vs. 0.910 U/mg protein, p<0.01) levels as well as catalase (0.463 vs. 4.948 BU/mg protein, p<0.001) activities were detected; while the plasma and erythrocyte lipid peroxidation and the reduced glutathione (GSH) levels did not change. The results of the investigated prooxidant and the antioxidant status provide evidence that there exists an oxidative stress in children with infantile autism. While investigating the hemorheological parameters of 25 infantile autistic patients, some characteristic pathological parameters were detected: the initial filtration rate (Fi) (0.72 vs. 0.75 p<0,01) and the clogging rate (CR) (1.926 vs. 2.912, p<0.01) values of red blood cells (RBC) decreased while the mean transit time (Tc) (8.93 vs. 7.39, p<0.001) increased suggesting reduced RBC deformability.]

Lege Artis Medicinae

JULY 14, 2007

[CONTROVERSIAL EFFECTS OF NITRIC OXIDE: INTEGRITY AND TOXICITY]

KISS Róbert Gábor, BÉRES Bernát János

[Nitric oxide is a key molecule of the human body. Since its discovery, a library of books and papers have been published on its physiological and pathophysiological role. It is involved in almost all pathological processes. In healthy individuals nitric oxide plays a crucial role in the vascular regulation by protecting against atherosclerosis, myocardial infarction and stroke. In the central nervous system, nitric oxide in its function as a neurotransmitter is responsible for synaptic plasticity, long-term potentiation, memory and a number of neuroendocrine control mechanisms. Furthermore, during inflammation and host defense, macrophages and neutrophils produce nitric oxide that has antibacterial, antiviral, and tumour cell killing activity. In pathologic conditions, however, nitric oxide reacts with superoxide anion to form peroxynitrite that damages the enzymes of the mitochondrial respiratory chain, superoxide-dismutase, reduced glutathion and activates or inactivates signalling molecules. During ischaemia- reperfusion, nitric oxide and peroxynitrite contribute to nitrative/nitrosative stress, DNAfragmentation and consequent polyADP-ribosepolymerase- 1 enzyme activation both in coronary thrombosis and ischaemic stroke.]

Lege Artis Medicinae

FEBRUARY 20, 2001

[The role of steroid hormones in the protection against oxidative stress]

BÉKÉSI Gábor, FEHÉR János

[The incidence of vascular diseases increases in postmenopausal women. This negative trend seems to be controllable favourably by hormone replacement therapy (HRT). Based on the free radical mediated mechanism of atherogenesis the authors try to find the reasons for these observations on the basis of their and others’ data. They consider the increase of activity and amount of neutrophil enzyme myeloperoxydase by certain steroid particulars one of the most important elements of the vasoprotective effect of HRT. This increase diminishes the production of superoxide anion by the inhibition of the NADPH-oxidase enzyme. The observation proved firstly by the authors, that the plasma levels of myeloperoxydase - and so the ability for the inhibition of superoxide anion production by neutrophils - decreases in elderly people, might explain the higher incidence of some free radical mediated illnesses in the elderly. The authors also give a short review of antioxidant effects of steroids in general.]