Lipid profile and lipid oxidative modification parameters in the first trimester of high- risk pregnancies - possibilities for preeclampsia prediction.

OBJECTIVES: The goal of this study was to investigate metabolic changes in lipids and oxidative stress parameters in the first trimester of pregnancy with the more specific aim of estimating the significance and strength of researched parameters in the prediction of preeclampsia. DESIGN AND METHODS: The study included 87 high-risk pregnant (HRG) female subjects, 14 with developed preeclampsia (PEC) and 43 healthy pregnant female subjects matched for gestational age (CG). Thiobarbituric acid-reactive substances (TBARS) concentration, lipid hydroperoxides (LOOH), pro-oxidant antioxidant balance (PAB) and total oxidative status (TOS) were measured as oxidative stress markers, while total antioxidant capacity (TAC) was measured as an antioxidative defense parameter. The Atherogenic Index of Plasma (AIP) was calculated as the base 10 logarithm of the ratio of the plasma concentration of triglycerides (TG) to the plasma concentration of high-density lipoprotein cholesterol (HDL-C), with each concentration expressed in mmol/L. RESULTS: The results have shown that lipid indices, especially AIP, were significantly higher in the first trimester of HRG (p < 0.001) and PEC (p < 0.001). Oxidative stress parameters were significantlly higher, while TAC was significantly lower in HRG vs. CG [0.7 ± 0.15 vs 1.1 ± 0.16; (p < 0.001)] and in PEC [0.6 ± 0.12 vs 1.1 ± 0.16; (p < 0.001)] vs. CG. Also, in the HRG, results have shown an independent association of AIP with the preeclampsia development (p < 0.05), while placental growth factor did not show the expected level of significance (p = 0.648). Analysis of the Receiver Operating Characteristics (ROC) curves indicated that certain parameters included in the research model have very good diagnostic accuracy for preeclampsia (AUC = 0.856). CONCLUSIONS: AIP is associated with high-risk pregnancies. Furthermore, our results firmly underscored AIP as a potential marker for preeclampsia prediction.

Extensive depolarization and lack of recovery of leech Retzius neurons caused by 2,4 diaminobutyric acid.

In this paper we present, for the first time, a detailed account of electrophysiological effects of 2,4-diaminobutyric acid (2,4-DABA). 2,4-DABA is a neurotoxic non-protein amino acid produced by Cyanobacteria with a possible link to neurodegenerative disorders in animals and humans. Intracellular recordings were performed on Retzius nerve cells of the leech Haemopis sanguisuga using glass microelectrodes filled with 3 mol/L KCl. Our results show that 2,4-DABA is an excitatory amino acid, causing membrane depolarization in a concentration-dependent manner. The most prominent depolarizations of 39.63±2.22 mV and 47.05±4.33 mV, induced by 5×10-3 and 10-2 mol/L 2,4-DABA respectively, are several times larger than maximal depolarizations induced by either Glutamate, Aspartate, ß-N-methylamino-alanine (BMAA) or ß-N-oxalylamino-alanine (BOAA) on our model. These 2,4-DABA induced depolarizations evolve through two distinct stages, which is a novel phenomenon in electrical cell activity upon application of an excitatory amino acid, at least on our model. Involvement of two separate mechanisms, suggested by the two stage phenomenon, is discussed in the paper. We also provide evidence that 2,4-DABA induces irreversible functional disturbances in neurons in a concentration-dependent manner, since only half of the cells recovered normal electrical activity after application of 5×10-3 mol/L 2,4-DABA, and none recovered after application of 10-2 mol/L 2,4-DABA. Effects of both L-2,4-DABA and DL-2,4-DABA were tested and are not significantly different.

Electrochemical monitoring of the breast milk quality.

The electrochemical techniques were used to determine the total antioxidant capacity of breast milks and the results were compared with a commonly used spectrophotometric (2,2-diphenyl-1-picrylhydrazyl, DPPH) method. Breast milk from mothers of preterm infants was monitored in three lactation phases and after storage of expressed milk by monitoring changes in the total antioxidant capacity over a two year period. Statistical analysis showed there was no significant difference between the ability of the three methods to detect changes in breast milk after storage. Either of the electrochemical techniques studied could be successfully used to replace the time-consuming spectrophotometric method and can be applied to clinical trials.

Distribution and accumulation of elements (As, Cu, Fe, Hg, Mn, and Zn) in tissues of fish species from different trophic levels in the Danube River at the confluence with the Sava River (Serbia).

Pikeperch (Sander lucioperca), European catfish (Silurus glanis), common carp (Cyprinus carpio), and gobies (Neogobius gymnotrachelus, Neogobius melanostomus) were collected from the Danube River (Belgrade section), and samples of liver, muscle, or whole-body composites (in the case of gobies) were analyzed for As, Cu, Fe, Hg, Mn, and Zn with inductively coupled plasma optical spectrometry to find out if there was a correlation between accumulation of these elements in predatory and prey species, as well as in pairs of species with overlapping diets. Concentrations of all analyzed elements were either higher (Cu, Fe, Mn, Zn) in liver than in muscle, or equal (As, Hg), except for Hg in carp, which was higher in muscle. Mercury concentration in liver and muscle of predators (catfish, pikeperch) was significantly (<10(-4)) higher than in prey fishes (carp and gobies). The results indicate that Hg concentration was biomagnified through the food chain. Concentrations of As, Fe, and Hg in carp liver and gobies whole-body composite were similar, but carp had significantly (<10(-4)) higher values of Zn and Cu in liver. The regression analysis and trendline equations indicate that the concentrations of all tested elements, except for As in liver, and Mn and Fe in muscle, were similar in predatory fish (pikeperch and catfish), on one hand, and in prey fish (carp and gobies), on the other hand. Distinctly high Zn concentration in carp is very common in this species due to its physiology. Concentrations of Hg and Zn were higher than the maximum acceptable concentration due to the high pollution level in this section of the Danube River, accordingly posing a risk for the human consumption of these fish species.

Independent complexity patterns in single neuron activity induced by static magnetic field.

We applied a combination of fractal analysis and Independent Component Analysis (ICA) method to detect the sources of fractal complexity in snail Br neuron activity induced by static magnetic field of 2.7 mT. The fractal complexity of Br neuron activity was analyzed before (Control), during (MF), and after (AMF) exposure to the static magnetic field in six experimental animals. We estimated the fractal dimension (FD) of electrophysiological signals using Higuchi's algorithm, and empirical FD distributions. By using the Principal Component Analysis (PCA) and FastICA algorithm we determined the number of components, and defined the statistically independent components (ICs) in the fractal complexity of signal waveforms. We have isolated two independent components of the empirical FD distributions for each of three groups of data by using FastICA algorithm. ICs represent the sources of fractal waveforms complexity of Br neuron activity in particular experimental conditions. Our main results have shown that there could be two opposite intrinsic mechanisms in single snail Br neuron response to static magnetic field stimulation. We named identified ICs that correspond to those mechanisms - the component of plasticity and the component of elasticity. We have shown that combination of fractal analysis with ICA method could be very useful for the decomposition and identification of the sources of fractal complexity of bursting neuronal activity waveforms.

Oxidative stress and anti-oxidative defense in schoolchildren residing in a petrochemical industry environment.

OBJECTIVE: To evaluate the possible relationship between industrial air pollution and oxidative stress in schoolchildren by comparing parameters from children residing in two nearby localities with contrasting environmental conditions. PARTICIPANTS: 42 schoolchildren (12-15 years) from Pancevo (site of Serbias largest petrochemical installation) formed the exposed group. 82 schoolchildren from Kovacica village, located 30 km north of Pancevo, formed the non-exposed group. METHODS: Oxidative stress status, anti-oxidative defense parameters, paraoxonase-1 status, lipid status, glucose concentration and leukocyte counts were compared in two groups. RESULTS: The children from Pancevo showed higher level of oxidative stress demonstrated by an elevated malondialdehyde concentration (P <0.001) and decreased superoxide dismutase activity (P<0.01) in comparison to the non-exposed group. CONCLUSIONS: The results suggested a relationship between the presence of air pollutants and increased oxidative stress in schoolchildren residing in an industrial environment.

Association of oxidative stress and PON1 with LDL and HDL particle size in middle-aged subjects.

BACKGROUND: Alterations in plasma lipoprotein subclass distributions affect atherosclerosis risk. Smaller, denser low-density lipoprotein (LDL) particles (sdLDL) are more susceptible to oxidation. In contrast, most of the protective effects of high-density lipoproteins (HDL) are attributable to larger particles. This study investigates the connection between LDL and HDL particle heterogeneity and oxidative stress, antioxidative defence (AOD) and paraoxonase (PON1) status in a healthy middle-aged Serbian population. MATERIALS AND METHODS: LDL and HDL particle sizes and subclass distributions were measured by gradient gel electrophoresis in 104 men and 103 women, aged 53 +/- 9.4 years. PON1 activities and PON1(Q192R) phenotypes were determined with paraoxon and diazoxon as substrates. The oxidative stress/AOD status was estimated by measuring malondialdehyde (MDA) and superoxide-anion (O2*(-)) levels and superoxide-dismutase (SOD) activity. RESULTS: Subjects with sdLDL had significantly higher MDA (P < 0.001) and O2*(-)(P < 0.05) levels and greater diazoxonase (DZOase) activity (P < 0.05) compared to subjects with larger LDL particles. A high MDA concentration was a significant predictor of the sdLDL phenotype (P < 0.005). Increased levels of and MDA were associated with smaller HDL(3) subclass abundance. Reduced HDL particle size was associated with lower DZOase activity (P < 0.01). CONCLUSIONS: Even in the absence of symptoms of atherosclerosis, sdLDL particles are associated with increased oxidative stress, which may stimulate a compensatory rise in PON1 DZOase activity. Elevated oxidative stress may significantly affect HDL subclass distribution, resulting in the accumulation of smaller, denser HDL particles with diminished antioxidative capacity.

Fractal analysis of rat brain activity after injury.

With application of the Higuchi algorithm, fractal dimension (FD) values of the electrocortical activity of the rat parietal cerebral and paravermal cerebellar cortex were calculated, before and after unilateral discrete injury of the left parietal cortex. Immediately following the first acute injury, in a group of six rats, a reversible increase in mean FD was found at the left (ipsilateral side to the injury) cerebral cortex, from 1.38 to 1.59, and at the left cerebellar cortex from 1.51 to 1.73. In addition, an indication of plastic changes after repeated (third) injury was found as an irreversible increase in mean FD: 1.54 on the left and 1.48 on the right side of parietal cortex.

Oxidative stress in diabetic pregnancy: SOD, CAT and GSH-Px activity and lipid peroxidation products.

Diabetic pregnancy is often complicated by a number of pathological conditions among which is increased oxidative stress. This study was conducted to investigate the parameters of oxidative stress in 90 patients divided into the three groups: pregnant women with Type 1 diabetes mellitus, healthy pregnant women and non-pregnant women. In pregnancy groups all parameters were followed in 1st, 2nd and 3rd trimester. Diabetic control was monitored by fasting blood glucose and glycosylated hemoglobin (HbA(1c)) and these values, as well as measured biochemical parameters (urea, creatinine, total cholesterol and uric acid), were appropriate throughout the study. The concentration of TBARS, as a measure of lipid peroxidation, and activity of antioxidant enzymes superoxide dismutase (Cu, Zn-SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) were investigated in hemolysate of erythrocytes. TBARS concentration increased significantly in pregnant women when compared with control group (non-pregnant women), as well as in pregnant diabetics compared with healthy pregnant women. The SOD activity was gradually increased in the group of normal pregnant women vs. non-pregnant group, but decreased significantly in the group of diabetic pregnant women. Catalase activity was significantly increased only in 3rd trimester diabetic pregnant women. Increased lipid peroxidation and reduced antioxidant status, despite good diabetic control, show that pregnant women are exposed to oxidative stress to a greater degree than controls.

Estimation of neuronal population activity changes in rat cerebellum using one electrode.

Activity of neuronal populations is usually measured with multielectrode systems. In this paper a procedure is described for estimating population activity changes in rat cerebellar cortex, using one microelectrode. Signals consisted of simple, complex spikes and interspike recorded background activity (RBA). After their separation, simple spikes were averaged, forming a simple spike template (SST). The remaining RBA was simulated (SBA), by superimposing SST waveforms with random time delays and intensities. A series of SBA was formed, differing in the superposition frequency (f(sup)) of individual SST. Mean amplitude spectra (Amp(SBA)) were calculated and Amp(SBA)=f(f(sup)) treated as a calibration line for estimating activity level of the surrounding neuronal population. Since the uniform probability distribution of SST intensities proved inadequate, we derived a new one, based on the power function for spike intensity vs. electrode distance attenuation. A family of new lines emerged, depending on the model parameters. Since all were linear in the log-log plots, with slopes not varying significantly, we proposed a method for estimating population activity changes in different experimental conditions, using two measured values of Amp(RBA). Relative nature of the results makes this method suitable for comparative studies.

Low serum alpha-1-antitrypsin specific activity in monoclonal gammopathies.

BACKGROUND: Serum alpha 1-antitrypsin (alpha 1AT) antigen concentration is elevated in malignancies as the result of acute phase reaction. In the present study, we examined whether the alpha 1AT elevation in monoclonal gammopathies was accompanied by an adequate increase of its functional activity. METHODS: In this case-control study, serum alpha 1AT concentration was measured in 187 ambulatory patients with monoclonal gammopathies and 320 healthy blood donors matched according to sex and age. The alpha 1AT antigen concentration was assayed by immunonephelometry, whereas its functional activity was measured as trypsin inhibitory capacity (TIC). The specific alpha 1AT inhibitory activity (SIA) was calculated, defined as the TIC/antigen concentration ratio. RESULTS: The alpha 1AT antigen concentrations obtained in the patients' samples were very significantly higher as compared with the corresponding values in the control group (mean +/- SD = 134 +/- 41.9% of normal, p < 0.001). However, the TIC values were higher in the patients than in the healthy controls only by 4% (104 +/- 23.8%, p < 0.05). The specific alpha 1AT activity was very significantly lower in the patients, as compared with the controls (p < 0.001), indicating that serum alpha 1AT in monoclonal gammopathies was partially inactive. CONCLUSIONS: As poor correlation between the TIC values and the antigen concentrations was obtained in the patient group as well as the decreased specific alpha 1AT activities, the TIC values in patients with monoclonal gammopathies should be interpreted with caution.

Simple and rapid method for the measurement of nitrite and nitrate in human plasma and cerebrospinal fluid by capillary electrophoresis.

Nitrite and nitrate levels in physiological fluids are commonly used as an index of nitric oxide production. We developed simple and rapid method for the determination of these anions by capillary zone electrophoresis employing borate buffer (pH 10, 100 mmol/l) as running electrolyte. The anions were analyzed in plasma and cerebrospinal fluid (CSF) without deproteinization of the samples. Electrophoresis was carried out in a capillary (36.5 cm x 75 microm) at a potential of 15 kV, with on-column UV detection at 214 nm. Mean retention times for nitrite and nitrates were 4.631 and 5.152 min, respectively. The method was linear (r=0.999) within a 1-500 micromol/l concentration range. Physiological levels of nitrate in plasma (40.2 micromol/l) and CSF (15.3 micromol/l) could be determined with good precision (coefficients of variation <6%) and accuracy (recoveries of added nitrate to plasma and CSF were 97.4 and 104.5%, respectively). Measurements of the physiological levels of nitrite in plasma (6.1 micromol/l) and CSF (0.9 micromol/l) were less precise and accurate.

The involvement of immune reactions in cardiac damage during acute myocardial infarction: role of cell-mediated immune response.

This study was undertaken with the aim of investigating humoral and cell-mediated immune response in acute myocardial infarction (AMI) as possible mechanisms involved in the infarction enlargement. Twenty three patients with first AMI and 15 healthy volunteers were examined. Of the AMI patients, 14 had extensive infarction (group A), while 9 patients had small infarction (group B). Immunologic analyses were performed at admission, and repeated after 3, 7, 14 and 21 days of the acute event. Following parameters were tested: number of CD3+, CD4+, CD8+ and CD20+ cells; serum IgG, IgA, IgM, C3, C4, immune complex and anticardiac antibody levels; polymorphonuclear cell (PMN) function (chemotaxis, phagocytosis, metabolic activity); leukocyte migration in vitro in the presence of water-soluble homologous heart extract. It was demonstrated that the number of B cells, serum IgG, C3, immune complex and anticardiac antibody levels were elevated from 7th-14th days after AMI. Concerning these parameters, however, no significant differences were obtained between group A and group B of AMI patients. Chemotaxis and metabolic activity of peripheral blood PMN, but not phagocytosis, were enhanced during AMI, again changes of PMN did not correlate with the extension of infarction. In contrast, leukocyte migration inhibition in vitro revealed that only patients with extensive AMI have developed positive reaction during the first 14 days after the onset of the disease, while leukocyte inhibition reaction appeared in patients with nonextensive AMI not earlier than the 21st day after the infarction. These findings demonstrate generation of immune reactivity during AMI and indicate that humoral immune response seems more likely to be an epiphenomenon related to tissue necrosis, while cell-mediated immune reactions could influence the extensiveness of cardiac damage.

Low frequency of PIM3 gene in patients with monoclonal gammopathies.

The distribution of PI (protease inhibitor) phenotypes and PI M subtypes was studied in 200 patients with monoclonal gammopathies and 320 healthy blood donors by isoelectric focusing in thin-layer polyacrylamide gels, pH range 4-5. The distribution of PI phenotypes and gene frequencies in the patients differed significantly from the corresponding values found in the blood donors, as shown by the chi 2 test (chi 2 = 16.5, p = 0.02 and chi 2 = 17.6, p = 0.0014, respectively). A lower frequency of the M3 variant was observed in patients, both in homozygous (PI M3) and heterozygous forms (PI M1M3 and PI M2M3). No significant difference between PIz allele frequencies in patients and healthy controls was found.

alpha-1-Antitrypsin (Pi) polymorphism in Serbia: deviation of Pi M subtype distribution from the Hardy-Weinberg equilibrium.

The distribution of the alpha 1-antitrypsin (Pi) phenotypes and subtypes was investigated in a population sample of 1060 unrelated individuals from Serbia (Yugoslavia). The allele frequencies estimates were: Pi*M1: 0.702; Pi*M2: 0.183; Pi*M3: 0.088; Pi*Z: 0.013, Pi*S: 0.007; Pi*P: 0.004; Pi*F: 0.003. The observed phenotype frequencies differed very significantly from those expected assuming H.W. equilibrium (chi 2 = 49.51, p < 0.0005). The deviation from equilibrium involved the three Pi*M subtypes: an excess of Pi*M1, Pi*M2 and Pi*M3 homozygotes was found, with the corresponding decreased number of M1M2 and M1M3 heterozygotes. The possible significance of this finding is discussed.

The estimation of fructosamine and HbAlc in pregnant women with diabetes mellitus.

Fructosamine, HbAlc, glucose, albumins and total proteins were estimated in 40 healthy pregnant women and 80 pregnant women with insulin dependent diabetes mellitus. Fructosamine was estimated by the NBT method with "Fructosamine test" commercially available kit on Technicom automatic analyser RA-1000. Glucose was determined on Beckman glucose analyser. HbAlc was assayed by the Bio-Rad test, while albumin and total proteins by Beckman tests. For all estimated parameters no significant differences were found between healthy pregnant women and pregnant women with insulin dependent diabetes mellitus.

Reference values for apolipoproteins A-I and B in healthy subjects, by age.

We determined reference values of apolipoproteins A-I (apo A-I) and B (apo B) in serum from a population of 448 healthy subjects (265 men and 183 women, ages 18 to 61 years) by a kinetic immunonephelometric procedure. Frequency distributions of apo A-I were normal, whereas those of apo B were not and yielded asymmetrical curves. Thus, reference intervals for apo A-I were determined as mean +/- 2SD (1.08-1.89 g/L), but a nonparametric method was used for determining reference intervals for apo B (0.60-1.94 g/L). Apo B concentrations were significantly higher (P less than 0.001) in men than in women (0.63-2.01 g/L, mean 1.21 g/L; and 0.54-1.91 g/L, mean 1.08 g/L, respectively). No significant differences for apo A-I between men and women were observed. Concentrations of both proteins increased with age, but apo B increased more than apo A-I. We conclude that not only sex but also the age of the subjects must be considered in interpreting laboratory results for apolipoproteins.