Reflection of Anxiety in the Characteristics of Evoked EEG Potentials in 10- to 11-Year-Old Children

We studied the peculiarities of the amplitude/time parameters of evoked EEG potentials (EPs) and event-related potentials (ERPs) in 10- to 11-year-old children characterized by low and high anxiety levels. The latter levels were estimated using the scale of the manifest anxiety test of Prikhozhan and projective techniques (“House–Tree–Person,” HTP, and the Lüscher color test). For children with a high anxiety level, the amplitudes of the following EP components and ERPs were lower than those in low-anxiety children of the same age: P1 (predominantly in the occipital region of the left hemisphere), P2 (in the right occipital region), and Р300 wave (in different loci of both hemispheres). In high-anxiety children, we also more frequently observed increased amplitudes of the N2 component in the left parietal and right occipital regions. High-anxiety individuals were characterized by longer latencies of component P1 (mostly in the right frontal and left central regions) and, at the same time, shorter latencies of component N1 (in the parietal and occipital regions of the left hemisphere and also in the right temporal region). Thus, we found that the amplitude/time characteristics of a few EP components and ERPs in children with high anxiety levels differ statistically significantly from the parameters of corresponding EPs/ERPs in individuals of the same age but with low anxiety levels.     

Correlations between characteristics of evoked EEG potentials recorded in a go/no-go paradigm and indices of attention in children

We studied correlations of the parameters of evoked EEG potentials (EPs) with the indices of attention in 30 children (12 years old). The EP were recorded in a two-stimulus go/no-go paradigm; the time of reaction was also measured. The indices of attention were measured using a Burdone test (correction trial) and Schulte’s tables. Optimum characteristics of attention were found in children with high amplitudes of the P2 component, P300 wave, and contingent negative deviation, low amplitudes of the N2 component, and small values of the latencies of the P1-N1-P2 complex. Neirofiziologiya/Neurophysiology, Vol. 37, Nos. 5/6, pp. 452–458, September–December, 2005.     

Correlations between EEG Characteristics and Contents of Some Micro- and Macroelements (Lead,Strontium, and Calcium) in the Organism of 12- to 13-Year-Old Children Living in Ecologically Unfavourable Regions of Ukraine

In 12- to 13-year-old children, inhabitants of regions of Ukraine with high levels of industrial contamination, we found higher contents of lead and calcium, as compared with the upper limits of the norm, in samples of biologically stable tissues (hairs). Concentrations of strontium were within the limits of reference values. Correlation analysis of the EEG frequency components vs levels of the above-mentioned metals demonstrated the existence of significant (or close to significant) relations between normalized spectral powers of the rhythms of background EEG recorded at different functional states (eyes open/closed, solving an arithmetic task) and concentrations of these elements. According to the number of the correlations found and their strength, the order of significance of the effects of the above elements with respect to the pattern of EEG activity was the following: Ca > Sr > Pb. The intensity of significant correlations varied from mild to moderately strong (0.41 < r < 0.70). The tightest correlations with the levels of all elements were observed under conditions of cognitive loading (solving an arithmetic task). High-frequency EEG components (β1 and β2 rhythms) were found to be the EEG components most sensitive to the contents of the mentioned elements.     

Magnesium,Calcium, and Trace Elements Excretion in 24-h Urine

Urine is a clinical specimen often used in medical diagnostics for monitoring of elements concentrations and kidneys function. We determined the contents of magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), lead (Pb), and cadmium (Cd) in 74 samples of 24-h urine (from 46 women and 28 men). The measurements were realized by the atomic absorption spectrometry (AAS) with atomization in the flame (FAAS) and in the graphite furnace (GFAAS). The received results were the subject of statistical analysis including the sex and age of volunteers. Moreover, correlations between the elements and the relationships between age and amounts of excreted elements with urine were tested. We found the statistically significant higher content of Zn in men’s urine than in women^’s one. Moreover, both adult women and men (>18 years) excreted much more Ca in urine in comparison to young subjects. Only in case of Pb the significant positive correlation between its amount in 24-h urine of all donors and age was stated. The correlation analysis has shown the significant positive relationships between Ca–Mg, Ca–Fe, Mg–Fe, Cu–Fe, Cu–Cd, Fe–Cd, and Pb–Cd in total samples of urine. Basing on our results, we concluded that the gender and age of donors may impact on the elemental status of 24-h urine.     

Dynamics of EEG potentials at the beginning of a series of EEG-feedback sessions

We studied changes in the amplitudes of event-related EEG potentials (ERPs) and power spectra of background EEG in the course of a series of EEG-feedback sessions directed toward an increase in the ratio of powers of the α vs θ rhythms. The examined group included 70 volunteers divided into an experimental group (n = 37) and a control group (n = 33). The intensity of acoustic white noise overlapping the musical background served as a feedback signal; it became lower with increase in the above ratio, while in the control group it remained constant. The EEG potentials were recorded from C3 and C4 leads. The ERPs were recorded within a paradigm of measuring time intervals. Within a series of EEG-feedback sessions, the α/θ ratio decreased somewhat both in the control and experimental groups, but in subjects of the latter group this decrease was less significant, and the mean intragroup index became significantly greater than the respective value in the control group after the end of the third session. The EEG-feedback sessions also resulted in significant increases in the amplitudes of early components of the readiness potential in both hemispheres and in the amplitude of the contingent negative variation in the right hemisphere. We conclude that, in most healthy subjects, at least three sessions of α/θ training are necessary to form an effective series providing considerable changes in the pattern of EEG potentials. Neirofiziologiya/Neurophysiology, Vol. 39, No. 1, pp. 88–98, January–February, 2007.     

The Content of Elements in Rainwater and Its Relation to the Frequency of Hospitalization for Gastric and Duodenal Peptic Ulcers in Opole Voivodship,Poland, During 2000–2002

The relationship between chemical elements in rainwater and the frequency of hospitalizations for gastric and duodenal peptic ulcers was studied on the population of the province (Voivodship) of Opole, Poland, during the years 2000–2002. There is a high positive correlation between hospitalized cases of gastric peptic ulcers with chromium in rainwater (r = 0.71), cadmium (r = 0.63), and lead (r = 0.70). Mild positive correlations were found with zinc (r = 0.55), copper (r = 0.56), iron (r = 0.57), chloride (r = 0.60), and sulfate (r = 0.52). These correlations were higher on men, suggesting that there are gender correlations involved. In duodenal peptic ulcers, we observed a high positive correlation between chromium in rainwater and hospitalized cases (r = 0.61) and mild positive correlations with lead (r = 0.57), copper (r = 0.52), and cadmium (r = 0.51). Significant gender differences were not found. These positive correlations may be due to the biological activity of the elements, such as their cytotoxic activity, enhanced local adrenergic stimulation on mucosal vasculature, ion channel (mainly calcium channels) remodeling, and, for example promoting infection by Helicobacter pylori.     

Modifications in the human EEG during extralong physical activity

In a single-case study, the effects of very long-lasting physical exercise, namely a 24-h-long ultramarathon, on the human electroencephalogram (EEG) were evaluated. While only effects of relatively short exercise have been reported earlier, we focused on the changes induced by these long-lasting physical requires. EEG was recorded repeatedly using an auditory oddball paradigm, and event-related potentials (ERPs), as well as changes in the current oscillatory brain activity (in particular, event-related desynchronization, ERD), were repeatedly monitored. While an increase in several attention-related ERP parameters was reported for shorter exercises, the results of our study show that cognitive performance-related EEG phenomena slowly decreased throughout the race. The P300 amplitude decreased, and the P300 latency increased with ongoing exercise duration. In addition, the difference between standard and target tones at N200b, as well as the difference in the lower alpha ERD, decreased with time, indicating a reduced automatic stimulus evaluation. Neirofiziologiya/Neurophysiology, Vol. 39, No. 1, pp. 81–87, January–February, 2007.     

Correlations between the level of aggressiveness of personality and characteristics of event-related EEG potentials

In a group of 76 adults of both sexes, we examined interrelations between the level of aggressiveness of the individual (diagnosed using the Buss-Durkee Hostility Inventory) and parameters of event-related EEG potentials (ERPs) recorded under conditions of two behavioral test acts including a motor component. Within the framework of task A, the subject must push a button with the shortest delay after an executory signal preceded by a warning signal; the time of sensorimotor reaction was measured. Under these conditions, we recorded the contingent negative variayion (CNV) and the P300 potential. In the case of task B, it was necessary to measure a definite time interval limited by two pushings of the button. Under these conditions, the readiness potential (RP) was recorded in addition to the CNV and P300. The C3 and C4 leads were used (according to the 10–20 system); the time constant of an amplification tract was 10 sec. Despite natural broad interindividual variability, high amplitudes of the recorded ERPs (RP, CNV, and P300) in general corresponded to lower indices by scales of the Buss-Durkee inventory and smaller values of the indices of aggressiveness and hostility. These interrelations are, probably, based on the fact that both characteristics of aggressiveness of the personality and EEG amplitude parameters are to a considerable extent determined by hereditary factors. It is believed that the respective peculiarities of the neurodynamic constitution of the individual are to a great extent dependent on the specificities of organization and functioning of a few neurotransmitter (in particular, aminergic) and neurohumoral systems. Neirofiziologiya/Neurophysiology, Vol. 39, No. 2, pp. 154–164, March–April, 2007.     

Correlations of Trace Element Levels in the Diet,Blood, Urine,and Feces in the Chinese Male

In order to explore the associations between trace elements in dietary intake and the other three biological media (blood, urine, or feces) and inter-element interactions among the latter, we simultaneously collected 72-h diet duplicates, whole blood, and 72-h urine and feces from 120 free-living healthy males in China. Correlations among the toxic (cadmium [Cd], lead [Pb]), and nutritionally essential (zinc [Zn], copper [Cu], iron [Fe], manganese [Mn], selenium [Se], iodine [I]) elements were evaluated using Spearman rank correlation analysis based on analytical data determined by inductively coupled plasma-mass spectrometry. Dietary Cd intakes were highly correlated with the fecal Cd and blood Cd levels. Inverse correlations were found for Fe–Cd and Fe–Pb in both diet versus blood and diet versus feces. Cd–Zn and Cd–Se were significantly directly correlated in the urine and feces. Cd–Se and Pb–Se were negatively correlated in blood. In addition, there existed an extremely significant association between urinary Se and urinary I. Moreover, the other two highly direct correlations were found for Se–Fe and for I–Fe in urine. Improved knowledge regarding their mutual associations is considered to be of fundamental importance to understand more the complex interrelationships in trace element metabolism.     

Comparative estimation of the neurotropicity of trace elements in the organism of children living in industrial towns of Ukraine

In 10- to 16-year-old children, inhabitants of industrial towns of Ukraine, an X-ray fluorescence analysis of the content of some chemical elements in hair samples allowed us to find a deficiency of Zn and Cu against the background of excesses of Ca, Cr, Ni, Mo, and Cd. Comparison of the parameters of EEG frequency components and levels of Ca, Zn, Cu, Fe, Mn, Co, Cr, Mo, Ni, Sr, Pb, and Cd showed that there are significant correlations between the normalized values of spectral powers of many frequency components of the ongoing EEG recorded in different functional states (eyes closed/open, solving an arithmetic task, and phono-/photostimulation) and concentrations of ten of the above-mentioned trace elements. Comparative estimation of the neurotropicity of the elements showed the following sequence of numbers of significant correlations (shown in parentheses) from the total set of possible comparisons: Cd (35) > Ni (31) > Cr (19) > Sr (17) > Pb (16) > > Ca (10) > Cu (7) > Mo (3) > Zn (2) > Fe (1). The intensity of correlations (values of the correlation coefficients) varied from 0.26 to 0.42 at 0.05 < P < 0.001; more frequently, such correlations were observed under conditions of EEG recording with the eyes closed (39) and upon solving an arithmetic task (33).     

Lead, Cadmium and Other Metals in Serum of Pet Dogs from an Urban Area of NW Poland

This study was designed to evaluate the degree of exposure of pet dogs from an urban area of NW Poland to selected metals, including toxic Cd and Pb. The study was conducted on a group of 48 healthy dogs. The serum concentration of the analysed elements followed the order Fe > Al > Zn > Cu > Mn > As > Sr > Pb > Cd > Cr > Ni > V. The presence of cadmium and lead was found in all the serum samples tested. The average contents of these elements were 0.309 and 0.489???g/mL. The factors that played the greatest role in the intake of the analysed elements were diet and breed-dependent size of dogs. Small-sized dogs had higher concentrations of all elements compared with large dogs, with statistically significant differences noted for Cu, Pb, Cd and Sr. It was also found that dogs receiving commercial and mixed food had more metals in serum compared with dogs on homemade food (except strontium). The present study showed elevated concentrations of some heavy metals (Pb, Cd, Fe and Cu) in serum of pet dogs, which is probably due to the excess elemental load of this area. Given that no information is available on the concentrations of strontium, vanadium and aluminium in dogs, further research is necessary to determine certain reference values which would allow for an easier interpretation of results and evaluation of exposure to these elements.     

The effect of selected trace metals on the fertilization success of several scleractinian coral species

This study provides new information on the effects of various concentrations of the trace metals copper, lead, zinc, cadmium, and nickel on fertilization success of gametes from the scleractinian reef corals Goniastrea aspera,Goniastrea retiformis, Acropora tenuis, and Acropora longicyathus. The EC50 values (the concentration that reduces the fertilization rate by 50% relative to the control fertilization) for copper effects on fertilization success of these coral species range from 15 to 40 μg/L, which is similar to responses of other marine invertebrates. The EC50 values for lead were 1450–1800 μg/L for the Acropora species, and >2400 μg/L for G. aspera gametes, which indicates that lead was much less toxic than copper. Fertilization responses to zinc and nickel were variable and a significant reduction in fertilization success for A. tenuis gametes was found only at very high cadmium concentrations. The data from this study and other recent research clearly demonstrate that some trace metals impair the fertilization success of gametes from faviid and acroporiid reef corals. Trace metal inputs into reef waters should be limited and controlled to avoid potential interference with sexual reproductive processes of reef corals.     

Metallic Elements in Hair as a Biomarker of Human Exposure to Environmental Pollution: A Preliminary Investigation in Hubei Province

Metallic elements in hair were assessed in human subjects randomly sampled from six villages in Hubei province, PR China, known to differ in industrial pollution. Metallic elements assessed included copper, zinc, lead, and cadmium. Subjects sampled included adults and children of both sexes. Soil and rice samples from the villages were also examined for contents of metallic elements. Soil and rice contents of copper, lead, and cadmium were higher in the villages closer to the pollution source (copper smeltery). Hair contents of copper, lead, and cadmium were higher in subjects from the polluted villages compared with subjects from the nonpolluted areas. No differences were found in hair zinc content among the villagers. Cadmium contents in rice and human hair were linearly correlated. For lead and copper a logarithmic relation was found. No difference was found between the two genders with respect to hair metallic contents. With regard to age, hair cadmium content was highest in the older age groups in the polluted villages and may reflect chronic exposure. No other systematic age effects were observed. It was concluded that contents of cadmium, lead, and copper in human hair do reflect the degree of environmental pollution.     

Dietary Exposure to Lead and Cadmium in Yugoslavia

Abstract

Lead exposure still represents a matter of health concern especially in Yugoslavia. To assess the exposure of normal urban population to lead and cadmium through food, a preliminary monitoring was performed on a small group of urban population. Lead, cadmium and some essential elements (calcium, zinc, iron, copper and manganese) were analysed in collected duplicate diet samples and compared to similar population in Sweden. We found that dietary exposure to lead and cadmium is similar to other countries although Yugoslav urban population is exposed to much higher concentrations of lead in air than in cities of developed countries, due to high lead in gasoline. However, daily intake of some essential elements was significantly lower.

Also populations living around lead smelters in various parts of Yugoslavia are still exposed to elevated environmental lead and cadmium levels. To assess the exposure of the population living in this area, a cumulative long-term exposure to lead was determined by measuring lead in deciduous teeth. Concentrations of lead and cadmium in vegetables, soil and meals from the same region were also analysed. Values obtained for lead and cadmium in food products grown in exposed and control area were found to be related to respective concentrations of these elements in soil as well as to the distance from the smelter. Meals prepared in this region show the same trend, revealing very high intake particularly of lead.

The influence of nutritional factors, i.e. dietary calcium on lead metabolism, was also studied. Blood lead concentration was determined in two groups of peasant women living in two regions with different dietary calcium intake. Lower blood lead values were found in the higher dietary calcium intake region.     

Chemical analysis of materials used in pig housing with respect to the safety of products of animal origin

Bedding, environmental enrichment materials and disinfectant powders in pig farming are meant to ensure a hygienic bedding environment or allow pigs to perform explorative behaviour. To our knowledge, no legal regulation exists, that established maximum contents for undesirable substances, such as toxic metals, dioxins or trace elements in these materials, although oral ingestion could be expected. In the present study, a total of 74 materials (disinfectant powders [n = 51], earth/peat [n = 12], biochar [n = 8], recycled manure solids [n = 3]) were analysed for their content of various toxic metals, trace elements, dioxins and polychlorinated biphenyls. The data suggest that, in some samples, trace elements like iron, copper and zinc might have been added intentionally in order to induce physiological effects (iron supply to piglets, copper and zinc as growth promoter in pigs). Moreover, some materials contained high levels of lead, cadmium or arsenic. Consequently, if farm animals repeatedly consume environmental enrichment and bedding materials or disinfectant powders in considerable amounts and these quantities are added to the daily ration, the amount of ingested undesirable substances and trace elements might exceed the maximum levels set for complete feedstuffs, and an elevated transfer into food of animal origin might occur. Future studies are required to address the possible quantitative contribution in the light of feed and food safety. Finally, the excretion of undesirable substances with manure needs to be considered due to their possible accumulation in soils.     

The Effect of Age and Gender on 38 Chemical Element Contents in Human Femoral Neck Investigated by Instrumental Neutron Activation Analysis

In the present study, the association of arsenic, cadmium, lead, and nickel between scalp hair samples and mortality from myocardial infarction (MI) patients at first, second, and third heart attack was studied. The biological samples of 130 MI patients (77 male and 53 female) age ranged (45–60 years), were collected and 61 healthy persons of same age group (33 male and 28 female) was selected as control subjects. The toxic elements (TEs) in biological samples were assessed by the electrothermal atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity of methodology was checked by the certified human hair reference material (BCR 397). It was observed during the study that 78% of 32 patients of the third MI, age >50 years were expired. In these subjects, the level of As, Cd, Ni, and Pb were increased by 10.6%, 19.5%, 15.7%, and 9.8% in the scalp hair as compared to those who tolerated third MI attack (p = 0.12). The high level of toxic metals may play a role in the development of heart disease in the subjects of this study.     

Metal interactions within and between tissues of nestling rooks Corvus frugilegus

We analyzed interactions of concentrations of 11 essential and nonessential elements, including toxic metals within and between internal organs (liver, kidney and lung), muscles and bones of nestling rooks Corvus frugilegus with acute cadmium contamination and elevated level of lead. The number of statistically significant (P ≤ 0.05) metal-metal relationships (positive/negative) within particular tissues was the highest in the kidney (7/6), following in the bone (9/2), liver (6/4), lung (5/2) and muscle (5/2). We found eight significant interactions of lead with other metals, and only two of cadmium (only with lead and cobalt, which probably mirrored a greater ability of lead (than in the case of cadmium) to functional and kinetic interaction with other metals, and/or inhibiting effect of lead or cadmium in co-accumulation. Furthermore, a positive relationship between concentration of cadmium and lead in the kidney could hint at the key importance of this organ in detoxification of both toxic metals. Analyses of relationships of individual metals between examined tissues show only positive results in the case of copper (n = 8), following potassium (n = 3), zinc and iron (in both cases n = 2) and a single ones for calcium and magnesium. We concluded that the lack of significant relationships of individual toxic metals (cadmium or lead) between analyzed tissues could result from high levels of these metals, which destroyed detoxifying capacity of kidney, and ultimately enabled a rapid bioaccumulation of these inorganic contaminations in all tissues of examined nestlings. An explanation of concentration of toxic metals in tissues of animals, especially in the case of their high level, require an identification of the actual level of essential elements associated with physiological status of organism.     

Cribra orbitalia and trace element content in human teeth from neolithic and early bronze age graves in southern Poland

Determination of element levels in bones and teeth can complement knowledge of the diagnostics and etiology of various diseases in prehistoric populations. Calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), and lead (Pb) content were analyzed in teeth from human skeletons dated to 3,000–1,400 BC from Malopolska Upland loess. Levels of iron and calcium were determined using atomic absorption spectroscopy (AAS), and lead, cadmium, and copper levels were measured using anodic stripping voltametry (ASV). Molar teeth from specimens with cribra orbitalia were selected for analyses, and teeth from specimens with no pathological changes were used as a control. No significant correlations between the content of particular elements and the tooth class, specimen age, or depth of burial pit were observed. The Fe content in specimens with cribra orbitalia is not the best measure for this disease's etiology. Thus, interelement correlations and proportions might give a better picture of the biological condition of the specimen and of the investigated groups. Am J Phys Anthropol 103:201–207, 1997. © 1997 Wiley-Liss, Inc.     

Biomonitoring of Lead and Cadmium in the Hair and Fingernails of Elderly Korean Subjects

Lead and cadmium are toxic to humans at excessive levels, and monitoring the human body burden of these metals is important in preventing adverse health effects. In this study, we assessed the exposure to lead and cadmium among an elderly population 60 years of age or older. Based on data from 115 participants, we found that the geometric mean lead concentrations in hair and fingernails were 1.11 μg/g [95% confidence interval (CI) 0.78–1.58] and 1.11 μg/g (95% CI 0.81–1.51), respectively. The lead concentrations in hair and fingernails were significantly related to cigarette smoking. The geometric mean cadmium concentrations in hair and fingernails were 52.6 ng/g (95% CI 42.0–65.9) and 40.1 ng/g (95% CI 29.9–53.9), respectively. Cadmium concentrations in hair were significantly related to body mass index and cigarette smoking, whereas higher fingernail cadmium concentrations were related to alcohol drinking. Correlations between hair and fingernail concentrations of lead and of cadmium were slightly positive. Our findings suggest that the body burden of lead and cadmium varies according to demographic factors, and hair and fingernails could be used differentially as a biological medium for metal exposure.     

Correlations of the Characteristics of Evoked EEG Potentials with the Neuroticism Level in Healthy Adults

We studied correlations between the estimates of the neuroticism level (one of the most significant factors of the emotional sphere of a personality) and the amplitude/time characteristics of evoked EEG potentials (EPs). Passive and negative emotiogenic, as well as neutral (from the emotional aspect) visual images (stimuli from the set of the International Affective Picture System, IAPS), were presented to 102 tested persons. The neuroticism level was estimated based on Eysenck’s personality questionnaire. We found that subjects with high estimates of the neuroticism level are characterized, in general, by somewhat higher rates and intensities of processing of emotionally negative information, a higher level of activation of the processes of automatic attention, and readiness to react to both significant and insignificant visual signals (with the aim of probably fighting of a threat). These peculiarities were manifested as relatively shorter latencies of the Р1, N1, Р2, N2, and Р3 components and as higher amplitudes of the Р2 component in the EPs induced by emotionally negative stimuli, as compared with the corresponding indices in subjects with a low neuroticism level. The amplitudes of the N2 component in the case of presentation of negative and neutral stimuli showed a trend toward a decrease. The approach used can be applied for obtaining objective indices interpreted as correlates of peculiarities of the emotional responsiveness typical of a personality.