Biological Effects of Trace Elements on Lateralized Exploratory Activity, Defensive Behaviour, and Epigenetic DNA Molecular Changes in Maturing Rats

2012 ◽  
Vol 4 (2) ◽  
pp. 167-175
Author(s):  
Silvia G. Ratti ◽  
Nora M. Vizioli ◽  
Eliana Gaglio ◽  
Edgardo O. Alvarez
Author(s):  
Thomas S. Bianchi

Like many other elements, natural background levels of trace elements exist in crustal rocks, such as shales, sandstones, and metamorphic and igneous rocks (Benjamin and Honeyman, 2000). In particular, the majority of trace metals are derived from igneous rocks, simply based on the relative fraction of igneous rocks in comparison with sedimentary and metamorphic rocks in the Earth’s crust. The release of trace metals from crustal sources is largely controlled by the natural forces of physical and chemical weathering of rocks, notwithstanding large-scale anthropogenic disturbances such as mining, construction, and coal burning (release of fly ash). As discussed later in the chapter, adjustments can be made for anthropogenic loading to different ecosystems based on an enrichment factor which compares metal concentrations in the ecosphere to average crustal composition. Biological effects of weathering, such as plant root growth and organic acid release associated with respiration also contribute to these weathering processes. As some trace metals are more volatile than others, release due to volcanic activity represents another source of metals with such properties (e.g., Pb, Cd, As, and Hg). Just as Goldschmidt (1954) grouped elements (e.g., siderophiles, chalcophiles, lithophiles, andatomophiles) based on similarities in geochemical properties, trace metals also represent a group of elements with similar chemical properties. One particularly important distinguishing feature of these elements is their ability to bond reversibly to a broad spectrum of compounds (Benjamin and Honeyman, 2000). Thus, the major inputs of trace metals to estuaries are derived from riverine, atmospheric, and anthropogenic sources. Although trace elements typically occur at concentrations of less than 1 ppb (part per billion) (or μg L−1, also reported in molar units), these elements are important in estuaries because of their toxic effects, as well as their importance as micronutrients for many organisms. The fate and transport of trace elements in estuaries are controlled by a variety of factors ranging from redox, ionic strength, abundance of adsorbing surfaces, and pH, just to name a few (Wen et al., 1999).


2010 ◽  
Vol 82 (2) ◽  
pp. iv
Author(s):  
Francesco Cubadda

Diet is the main source of trace elements, and exposure to dietary trace elements has a direct impact on the health of hundreds of millions worldwide. Insufficient intake of essential trace elements is a global issue. Deficiencies of iron, zinc, iodine, and selenium result in millions of people being affected by various diseases, with very serious consequences in those countries where malnutrition is widespread. On the other hand, the impact of toxic element species such as inorganic arsenic and methylmercury on entire populations has come to the fore again as a priority for both the scientific community and health authorities. The presence of trace elements in feeds, either as contaminants or as nutritional or zootechnical additives, and their transfer across the food chain to humans also raises questions within the scientific community and regulators.Different facets of trace elements, from essentiality to toxicity, were addressed throughout the 3rd International IUPAC Symposium on Trace Elements in Food (TEF-3). The meeting was organized by the Istituto Superiore di Sanità and held on 1-3 April 2009 in Rome, Italy. The objective was to gather experts with different backgrounds to discuss all aspects of trace elements in food in relation to human health, with special emphasis on biological effects of elements. The main topics included essentiality, toxicity, bioaccessibility, bioavailability, speciation, sources and transfer in the food chain, effects of processing, food and feed fortification, supplementation, international legislation and standards, analytical developments, analytical quality assurance and reference materials. In accordance with practice in previous events of this series (Warsaw, 2000, and Brussels, 2004), TEF-3 provided a forum for the exchange of new ideas and experiences in trace element research, and a basis for influencing policy, advisory practice, and risk-management tools to protect public health.Over 200 participants, representing some 40 countries, joined the event. In addition to the 15 invited lectures, delegates from Europe, Asia, Africa, North and South America enriched this edition with 20 oral and about 130 poster contributions. TEF-3 actually resulted in a lively interdisciplinary symposium on current and emerging research and development efforts.Special emphasis was placed on the following topics:- analytical techniques for element speciation studies in food and food supplements- reliability and quality control of analytical data on trace elements in foodstuffs- detection, characterization, and potential health risks of inorganic nanoparticles- arsenic speciation and toxicology- gender differences in susceptibility to toxic trace elements in food- exposure assessment of toxic element species- assessment of risks and benefits of the organic forms of trace elements as feed additives- metabolism of metal(loid)s by intestinal microorganisms- absorption and metabolism of iron, zinc, and other essential elements- use of stable isotopes to study trace mineral metabolism- selenium and iodine speciation and biological effectsAdvancements in the above-mentioned areas were discussed, and special attention was paid to the means in order to prevent adverse health effects on those individuals and populations most vulnerable to trace-element inadequacies, excesses, or imbalances.The following collection of papers based upon authoritative lectures presented at TEF-3 addresses many of the topics discussed during the symposium. Overall, it provides an excellent overview of the state of the art in the area of trace elements in food and sheds light on future challenges and subjects of research.Francesco CubaddaConference Chair


2013 ◽  
Vol 3 (4) ◽  
pp. 389-392 ◽  
Author(s):  
Jeganathan Manivannan ◽  
Janakiraman Shanthakumar ◽  
Krishnamoorthy Rajeshwaran ◽  
Pandiyan Arunagiri ◽  
Elumalai Balamurugan

Author(s):  
Stanley C. Skoryna ◽  
Sadayuki Inoue ◽  
M. Fuskova

1989 ◽  
Vol 44 (1-2) ◽  
pp. 170-172 ◽  
Author(s):  
S. Scheller ◽  
M. Czauderna ◽  
W. Krol ◽  
J. Konecki ◽  
Z. Czuba ◽  
...  

Abstract Propolis is a natural composite balsam, manufactured by honey bees, and active biochemically. Some of its biological effects are attributed to its ability to stimulate enzymatic systems, which in many instances involve trace elements. In the present study we assayed propolis and its ethanolic extract (EEP) for trace elements, and quantified them with the aid of neutron activation analysis. Four elements that have been detected in propolis and EEP for the first time are Na. Cr, Co (ppm) and Ag (ppb). The wide concentration range of the inorganic components in various batches of propolis and EEP is due to the difference in their extraction capacities, and to the variability in the environmental pollutants and the flora at the beehive sites.


Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.


Author(s):  
O.T. Woo ◽  
G.J.C. Carpenter

To study the influence of trace elements on the corrosion and hydrogen ingress in Zr-2.5 Nb pressure tube material, buttons of this alloy containing up to 0.83 at% Fe were made by arc-melting. The buttons were then annealed at 973 K for three days, furnace cooled, followed by ≈80% cold-rolling. The microstructure of cold-worked Zr-2.5 at% Nb-0.83 at% Fe (Fig. 1) contained both β-Zr and intermetallic precipitates in the α-Zr grains. The particles were 0.1 to 0.7 μm in size, with shapes ranging from spherical to ellipsoidal and often contained faults. β-Zr appeared either roughly spherical or as irregular elongated patches, often extending to several micrometres.The composition of the intermetallic particles seen in Fig. 1 was determined using Van Cappellen’s extrapolation technique for energy dispersive X-ray analysis of thin metal foils. The method was employed to avoid corrections for absorption and fluorescence via the Cliff-Lorimer equation: CA/CB = kAB · IA/IB, where CA and CB are the concentrations by weight of the elements A and B, and IA and IB are the X-ray intensities; kAB is a proportionality factor.


Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.


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