To evaluate oxidative stress in type I diabetes mellitus, two antioxidant enzymes in erythrocytes, copper-zinc superoxide dismutase (SOD EC 1.15.1.1.) and seleno-dependent glutathione peroxidase (GSH-Px; EC 1.11.19), and two indexes of peroxidation in plasma, thiobarbituric acid reactive substances (TBARS) and organic hydroperoxides (OHP), were measured in 118 patients with insulin-dependent diabetes mellitus (IDDM), classified in accordance with the presence or absence of vascular complications and the degree of metabolic control established by the HbA1c level. Ninety healthy subjects made up the control group. According to our results, plasmatic TBARS and OHP concentrations are significantly higher in diabetics than in controls, and these differences are accentuated in diabetic people with vascular disorders. The GSH-Px activity was significantly reduced in diabetic patients with poor and medium metabolic control in relation to the control group, regardless of the existence or absence of vascular disorders. No differences in SOD activity between diabetic and control groups were found. A significant positive correlation between TBARS and HPO (r=0.683, p<0.001) was found in both the control and diabetic groups. Among the lipid parameters studied, there were only significantly positive correlations between TBARS and total cholesterol; TBARS and triglycerides; OHP and total cholesterol and OHP and triglycerides. Positive correlations between TBARS and HbA1c and between OHP and and HbA1c, and negative correlations between GSH-Px and HbA1c and between SOD and HbA1c were also found. The multiple regression analysis shows that TBARS and HPO correlate negatively with GSH-Px. There was no significant correlation with SOD.

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SummaryAn optimization and comparison of three atomic absorption spectroscopic methods for measuring Ca, Mg, Na, K and Fe contents of infant formulas are carried out. The first method is a direct measure of a sample dispersion in water. The second method involves a previous wet digestion (HNO, + H,OJ in a microwave oven. And finally a dry mineralization at 450 "C is assayed. In order to measure Ca and Mg lanthanum at 0.4% concentration and in the case of Na and K cesium at 0.1 % were added.The analytical parameters of the three methods assayed were determined. Results obtained show that the three studied methods are accurdce and reliable and no significant difference among them at a probability level of 99% were found.Given the fact that the direct measure of the dispersed sample is the most simple and costless, it could be recommended to measure Ca, Mg, Na, K and Fe in infant formulas. ZusammenfassungDirektbestimmung von Calcium, Magnesium, Natrium, Kalium und Eisen in Babynahrung mittels Atomspektroskopie. Vergleich von Trocken-und NaDaufschluBverfahren Drei atomspektroskopische Bestimmungsverfahren fur Calcium, Magnesium, Natrium, Kalium und Eisen in Sauglingsfertignahrung wurden optimiert und verglichen. Die erste Methode ist eine direkte Bestimmung der Zielelemente nach Auflosung der Probe in Wasser. Die zweite Methode setzt einen vorherigen NaljaufschluR (HNO, + H,Oz) der Probe im Mikrowellenofen voraus. Bei der dritten Methode wird die organische Materie auf trockenem Weg bei 450 "C zerstort. Fur die Calcium-und Magnesiummessung wird Lanthan bis zu einer Endkonzentration von 0,4% zugegeben und fur die Natrium-und Kaliumbestimmung Caesium in 0,l %iger Konzentration.Die analytischen Parameter der drei untersuchten Verfdhren werden bestimmt. Die Ergebnisse zeigen, daR die drei Methoden ausreichend prazise und exakt sind und dalj bei einem Wahrscheinlichkeitsniveau von 99% keine signifikanten Unterschiede bestehen. Als Routineverfahren fur die Bestimmung der Zielelemente Ca, Mg, Na, K und Fe in Sauglingsfertignahrung wird die Direktbestimmung nach vorangegangener Dispersion der Probe in Wasser und anschlieknder Messung durch Atomabsorptionsspektroskopie vorgeschlagen. Diese Methode ist die einfachste und benotigt den geringsten materiellen und zeitlichen Aufwand.

Several techniques based on different principles have been proposed to measure lipid hydroperoxides. Enzymatic methods are sensitive and can be quite specific but they are subject to interference by inhibitors and not all are stoichiometric. The present work proposes some modifications of the Heath & Tappel (Anal Biochem 1976; 7:184-91) enzymatic method of determination of lipid hydroperoxides in order to standardize and automate it and to meet the analytical criteria required for a biological assay. The proposed new protocol and the automated assay give acceptable within-run and between-run precisions, with coefficients of variation of 3.34% and 5.80%, respectively, at the usual plasma lipid hydroperoxides content. The recovery is 98.7 ± 4.89%, and the method is linear for a wide range of contents and sensitive (10 μπιοΐ/ΐ) enough to measure the plasma lipid hydroperoxides content. ') Enzymes: Glutathione peroxidase (EC 1.11.1.9) Glutathione reductase (EC 1.6.4.2) Brought to you by |

Summary: A 67 year old woman with widespread atherosclerosis and diabetic nephropathy manifested by nephrotic syndrome and moderate renal failure developed multiple hepatic infarctions. The infarctions were documented by computed tomographic scan and needle aspiration biopsy of the liver. Except for the nephrotic syndrome and the atherosclerosis no other cause of hepatic infarction was found.We suggest that hepatic infarction should be considered in the thrombotic complications ofthe nephrotic syndrome secondary to diabetic nephropathy.