EDTA chelation effects on urinary losses of cadmium, calcium, chromium, cobalt, copper, lead, magnesium, and zinc

The efficacy of a chelating agent in binding a given metal in a biological system depends on the binding constants of the chelator for the particular metals in the system, the concentration of the metals, and the presence and concentrations of other ligands competing for the metals in question. In this study, we make a comparison of the in vitro binding constants for the chelator, ethylenediaminetetraacetic acid, with the quantitative urinary excretion of the metals measured before and after EDTA infusion in 16 patients. There were significant increases in lead, zinc, cadmium, and calcium, and these increases roughly corresponded to the expected relative increases predicted by the EDTA-metal-binding constants as measured in vitro. There were no significant increases in urinary cobalt, chromium, or copper as a result of EDTA infusion. The actual increase in cobalt could be entirely attributed to the cobalt content of the cyanocobalamin that was added to the infusion. Although copper did increase in the post-EDTA specimens, the increase was not statistically significant. In the case of magnesium, there was a net retention of approximately 85% following chelation. These data demonstrate that EDTA chelation therapy results in significantly increased urinary losses of lead, zinc, cadmium, and calcium following EDTA chelation therapy. There were no significant changes in cobalt, chromium, or copper and a retention of magnesium. These effects are likely to have significant effects on nutrient concentrations and interactions and partially explain the clinical improvements seen in patients undergoing EDTA chelation therapy.     

Reference values for the concentrations of As,Cd, Co,Cr, Cu,Fe, I,Hg, Mn,Mo, Ni,Pb, Se,and Zn in selected human tissues and body fluids

This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.     

Earth, sky, wind, and weather

This paper seeks to understand what it means to live 'in the open'. It begins with an account of experiments that test whether children have acquired a scientifically correct understanding of the shape of the earth, according to which people live all around on the outside of a solid sphere. This understanding cannot accommodate the phenomenon of the sky, in relation to which the earth can appear only as the ground of human habitation. James Gibson's ecological approach to perception offers a possible alternative, depicting earth and sky as complementary hemispheres. Yet for Gibson, this earth-sky can be inhabited only insofar as it is furnished with objects. To that extent, it ceases to be open. Drawing on elements of Merleau-Ponty's phenomenology, it is argued that in the open world persons and things relate not as closed forms but by virtue of their common immersion in the generative fluxes of the medium – in wind and weather. Fundamental to life is the process of respiration, by which organisms continually disrupt any boundary between earth and sky, binding substance and medium together in forging their own growth and movement. Thus to inhabit the open is not to be stranded on the outer surface of the earth but to be caught up in the transformations of the weather-world.     

Uniform hypothesis of cell behavior--movement, contact inhibition of movement, adhesion, chemotaxis, phagocytosis, pinocytosis, division, contact inhibition of division, fusion.

The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.     

Wineries,drosophila, alcohol,and Adh

Summary Previous workers (McKenzie and Parsons, 1972, 1974; McKenzie, 1974; Briscoe et al., 1975) have found anomalous distributions of species of Drosophila, of sexes of D. melanogaster, and of Adh alleles in and around wineries in Australia and Spain. Field studies in California's Sonoma Valley provide evidence that the explanations advanced for these distributions may incorrect. The anomalous distribution of species was attributed to alcohol, either as a selective agent or as a behavioral stimulus. We find a virtually identical species distribution in the absence of environmental alcohol. The anomalous sex ratio was attributedd to differential survivall of the sexes when raised on alcohol. We present crude evidence thatehe difference may simply be a behavioral response to some product of fermentation, which need not be alcohol. Finally, the allele frequency difference reported from Spain was attributed to differential adult mortality on alcohol. We do not find an allele frequency difference even when alcohol is exposed, and therefore suggest that selection is occurring in pre-adult stages.     

Definitions,measurements, and classifications of stimuli,situations, and environments

A review is presented of issues relevant to the definition, measurement, and classification of stimuli, situations, and environments. Problems such as the lack of adequate definitions of concepts, error and bias in measurement procedures, confusion between measurement of a concept and measurement of its behavioral effects, and the lack of agreement among alternative measures are emphasized. It is suggested that concepts be defined in terms of objective characteristics while allowing for the study of the transactional relationship between organism and environment. The work of the ethologists in defining stimuli while studying their relationship to different organismic states and situational contexts is emphasized in this regard. Following Brunswik, it is also suggested that wherever possible there be a representative sampling of variables in natural settings. Note from the editors: From time to time, Human Ecology will publish a review article. Our first in this series is a review by a psychologist of basic definitional and conceptual problems in environmental studies.This paper was prepared while the author was a Visiting Research Fellow at the Educational Testing Service. The support of ETS and my colleagues in the Division of Psychological Studies is gratefully acknowledged. The review was also supported in part by a grant from the Rutgers University Research Council.     

The Sarcocystidae: Sarcocystis,Frenkelia, Toxoplasma,Besnoitia, Hammondia,and Cystoisospora1

Members of the family Sarcocystidae, as defined by Frenkel, have had a complicated history, principally due to the existence of both coccidial and cystic stages. This formerly clandestine relationship resulted in dual or partial designations of nomenclature for individual species. The problem was further compounded by the obligatory heteroxeny of several of the genera, making it impossible to transmit the parasites from one individual to another of a single host. As a result, oocysts similar in appearance, though from hosts separated taxonomically up to the familial level, were sometimes considered to be identical. Discoveries within the last decade have generated much interest and some understanding. Current studies of these and other coccidia should emphasize complete cyclical transmissions with cognizance of potential heteroxeny with the production of tissue cysts in intermediate hosts.     

Fat,sex, class,adaptive flexibility,and cultural change

In modern industrial nations, the traditional positive correlation between female body fat and social class has turned strongly inverse, thinness in women is admired and plumpness is a handicap. This recent reversal of what had seemed to be stable aspects of human nature is analyzed as a potentially adaptive response to two ecological novelties: chronic food surplus and the breakdown of barriers between men's and women's work, which, together, may have made thinness helpful to women competing for status and resources in both mating and job markets. Whether status and resources still promote long-term Darwinian fitness is an open question. Progress in understanding the unique properties of the human mind depends on widespread recognition that the mind has been designed by natural selection to seek and sometimes find adaptive solutions to the novel problems we ourselves create. Adaptive flexibility and cultural change are two sides of the same coin.     

Substance,rights, value,and abortion

Most serious contemporary opposition to abortion is grounded on the belief that human fetuses are members of the same moral category as beings like us, and that the loss of any such life is one of the worst possible losses. Substance view theorists oppose abortion for this reason: in their view beings like us are essentially rational substances with inherent moral worth, and those who perform induced abortion fail to recognize this moral worth. In a recent series of articles, Rob Lovering presents reductio‐style arguments against the substance view, in part arguing that it is inconsistent with our intuitions in rescue and spontaneous abortion cases. In a recent reply, Henrik Friberg‐Fernros argues that the substance view can evade these problematic implications because of a distinction between killing and letting die. According to this argument, the fetus’s right to life is a negative right not to be killed, not a positive right to be rescued, thus the anti‐abortion theorist who lets fetuses die acts acceptably. I argue this stance fails to recognize the inherent moral worth that the substance view contends fetuses possess. One who refrains from saving a person, or doesn’t care how many people she saves, cannot reasonably claim to value life. Furthermore, this stance is at odds with most contemporary anti‐abortion views that oppose induced abortions of both the killing and letting die variety.     

Cadmium transport, resistance, and toxicity in bacteria, algae, and fungi

Cadmium is an important environmental pollutant and a potent toxicant to bacteria, algae, and fungi. Mechanisms of Cd toxicity and resistance are variable, depending on the organism. It is very clear that the form of the metal and the environment it is studied in, play an important role in how Cd exerts its effect and how the organism(s) responds. A wide range of Cd concentrations have been used to designate resistance in organisms. To date, no concentration has been specified that is applicable to all species studied under standardized conditions. Cadmium exerts its toxic effect(s) over a wide range of concentrations. In most cases, algae and cyanobacteria are the most sensitive organisms, whereas bacteria and fungi appear to be more resistant. In some bacteria, plasmid-encoded resistance can lead to reduced Cd2+ uptake. However, some Gram-negative bacteria without plasmids are just as resistant to Cd as are bacteria containing plasmids encoding for Cd resistance. According to Silver and Misra (1984), there is no evidence for enzymatic or chemical transformations associated with Cd resistance. Insufficient information is available on the genetics of Cd uptake and resistance in cyanobacteria and algae. Mechanisms remain largely unknown at this point in time. Cadmium is toxic to these organisms, causing severe inhibition of such physiological processes as growth, photosynthesis, and nitrogen fixation at concentrations less than 2 ppm, and often in the ppb range (Tables 2 and 3). Cadmium also causes pronounced morphological aberrations in these organisms, which are probably related to deleterious effects on cell division. This may be direct or indirect, as a result of Cd effects on protein synthesis and cellular organelles such as mitochondria and chloroplasts. Cadmium is accumulated internally in algae (Table 4) as a result of a two-phase uptake process. The first phase involves a rapid physicochemical adsorption of Cd onto cell wall binding sites, which are probably proteins and (or) polysaccharides. This is followed by a lag period and then a slow, steady intracellular uptake. This latter phase is energy dependent and may involve transport systems used to accumulate other divalent cations, such as Mn2+ and Ca2+. Some data indicate that Cd resistance, and possibly uptake, in algae and cyanobacteria is controlled by a plasmid-encoded gene(s). Although considerable information is available on Cd toxicity to, and uptake in fungi, further work is clearly needed in several areas. There is little information about Cd uptake by filamentous fungi, and even in yeasts, information on the specificity, kinetics, and mechanisms of Cd uptake is limited.(ABSTRACT TRUNCATED AT 400 WORDS)     

Microbes, warfare, religion, and human institutions

A significant number of practicing microbiologists are not aware of the historical impact of infectious agents on the development of human institutions. Microbes have played a profound role in warfare, religion, migration of populations, art, and in diplomacy. Boundaries of nations have changed as a result of microbial diseases. Infectious agents have terminated some kingdoms and elevated others. There is a need for microbiologists to have a historical perspective of some of the major ways in which a pathogen may influence civilized populations. Conditions may exist in contemporary society for a repeat of some of the kinds of plagues suffered by previous societies. The purpose of this paper is to review examples of situations where pathogenic microbes have forced societal modifications on centers of human population.     

Genes, exercise, growth, and the sedentary, obese child.

It is still not possible to provide an evidence-based answer to the question of whether regular exercise is essential for normal growth. It is also unclear whether very low levels of exercise result in growth deficits. Regular exposure to exercise is characterized by heterogeneity in responsiveness, with most individuals experiencing improvements in fitness traits but a significant proportion showing only very minor gains. Whether a sedentary mode of life during the growing years results in a permanent deficit in cardiorespiratory fitness or a diminished ability to respond favorably to regular exercise later in life remains to be investigated. Although several genes have been associated with fitness levels or response to regular exercise, the quality of the evidence is weak mainly because studies are statistically underpowered. The special case of the obese, sedentary child is discussed, and the importance of the "energy gap" in the excess weight gain during growth is highlighted. Obese, sedentary children have high blood pressure, dyslipidemia, elevated glycemia and type 2 diabetes, hepatic steatosis, respiratory problems, orthopedic complications, and other health disorders more frequently than normal weight, physically active children. The role of genetic differences in the inclination to be sedentary or physically active is reviewed. An understanding of the true role of genetic differences and regular exercise on the growth of children will require more elaborate paradigms incorporating not only DNA sequence variants and exercise exposure but also information on nutrition, programming, and epigenetic events during fetal life and early postnatal years.     

FRAP, FLIP, FRET, BRET, FLIM, PRIM...new techniques for a colourful life

Cell and tissue imaging provides scientists with wonderful tools, thanks to a fruitful dialog between chemistry, optical, mechanical, computational sciences and biology. Confocal microscopy, videomicroscopy together with a new generation of fluorochromes (especially those derived from green fluorescent protein, GFP) and image analysis software allow to visualize life in all its dimensions (space and time). Cell imaging also allows to quantify biological processes at the cellular level, to analyse both stoechiometry and dynamics of molecular interactions involved in cell and tissue regulations. Entering the new era of post-genomics requires a better knowledge of advantages and limitations of these new approaches.     

Bioavailability of selenium from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine, and sodium selenite assessed in selenium-deficient rats

The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine (SeMet), and sodium selenite was assessed in Se-deficient Fischer-344 rats. Se as veal, chicken, beef, pork, lamb, flounder, tuna, SeMet, and sodium selenite was added to torula yeast (TY) basal diets to comprise Se-inadequate (0.05 mg Se/kg) diets. Se as sodium selenite was added to a TY basal diet to comprise a Se-adequate (0.10 mg Se/kg), Se-control diet. The experimental diets were fed to weanling Fischer-344 rats that had been subjected to dietary Se depletion for 6 wk. After 9 wk of the dietary Se repletion, relative activity of liver glutathione peroxidase (GSHPx) from the different dietary groups compared with control rats (100%) was: flounder 106%, tuna 101%, pork 86%, sodium selenite 81%, SeMet 80%, beef 80%, chicken 77%, veal 77%, and lamb 58%. Se from flounder was the most efficient at restoring Se concentrations in the liver and skeletal muscle. Se from sodium selenite, SeMet, beef, veal, chicken, pork, lamb, and tuna was not dietarily sufficient to restore liver and muscle Se after 9 wk of recovery following a 6-wk period of Se depletion.     

Lymnaea schirazensis, an overlooked snail distorting fascioliasis data: genotype, phenotype, ecology, worldwide spread, susceptibility, applicability

Background

Lymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity.

Methodology/Principal Findings

A ten-year study in Iran, Egypt, Spain, the Dominican Republic, Mexico, Venezuela, Ecuador and Peru, demonstrated that such heterogeneity is not due to susceptibility differences, but to a hitherto overlooked cryptic species, Lymnaea schirazensis, confused with the main vector Galba truncatula and/or other Galba/Fossaria vectors. Nuclear rDNA and mtDNA sequences and phylogenetic reconstruction highlighted an old evolutionary divergence from other Galba/Fossaria species, and a low intraspecific variability suggesting a recent spread from one geographical source. Morphometry, anatomy and egg cluster analyses allowed for phenotypic differentiation. Selfing, egg laying, and habitat characteristics indicated a migration capacity by passive transport. Studies showed that it is not a vector species (n = 8572 field collected, 20 populations): snail finding and penetration by F. hepatica miracidium occur but never lead to cercarial production (n = 338 experimentally infected).

Conclusions/Significance

This species has been distorting fasciolid specificity/susceptibility and fascioliasis geographical distribution data. Hence, a large body of literature on G. truncatula should be revised. Its existence has henceforth to be considered in research. Genetic data on livestock, archeology and history along the 10,000-year post-domestication period explain its wide spread from the Neolithic Fertile Crescent. It is an efficient biomarker for the follow-up of livestock movements, a crucial aspect in fascioliasis emergence. It offers an outstanding laboratory model for genetic studies on susceptibility/resistance in F. hepatica/lymnaeid interaction, a field of applied research with disease control perspectives.     

Scaling of differentiation in networks: nervous systems,organisms, ant colonies,ecosystems, businesses,universities, cities,electronic circuits,and Legos

Nodes in networks are often of different types, and in this sense networks are differentiated. Here we examine the relationship between network differentiation and network size in networks under economic or natural selective pressure, such as electronic circuits (networks of electronic components), Legos (networks of Lego pieces), businesses (networks of employees), universities (networks of faculty), organisms (networks of cells), ant colonies (networks of ants), and nervous systems (networks of neurons). For each of these we find that (i) differentiation increases with network size, and (ii) the relationship is consistent with a power law. These results are explained by a hypothesis that, because nodes are costly to build and maintain in such "selected networks", network size is optimized, and from this the power-law relationship may be derived. The scaling exponent depends on the particular kind of network, and is determined by the degree to which nodes are used in a combinatorial fashion to carry out network-level functions. We find that networks under natural selection (organisms, ant colonies, and nervous systems) have much higher combinatorial abilities than the networks for which human ingenuity is involved (electronic circuits, Legos, businesses, and universities). A distinct but related optimization hypothesis may be used to explain scaling of differentiation in competitive networks (networks where the nodes themselves, rather than the entire network, are under selective pressure) such as ecosystems (networks of organisms).     

Landscape, flux, correlation, resonance, coherence, stability, and key network wirings of stochastic circadian oscillation

Circadian rhythms with a period of ∼24 h, are natural timing machines. They are broadly distributed in living organisms, such as Neurospora, Drosophila, and mammals. The underlying natures of the rhythmic behavior have been explored by experimental and theoretical approaches. However, the global and physical natures of the oscillation under fluctuations are still not very clear. We developed a landscape and flux framework to explore the global stability and robustness of a circadian oscillation system. The potential landscape of the network is uncovered and has a global Mexican-hat shape. The height of the Mexican-hat provides a quantitative measure to evaluate the robustness and coherence of the oscillation. We found that in nonequilibrium dynamic systems, not only the potential landscape but also the probability flux are important to the dynamics of the system under intrinsic noise. Landscape attracts the systems down to the oscillation ring while flux drives the coherent oscillation on the ring. We also investigated the phase coherence and the entropy production rate of the system at different fluctuations and found that dissipations are less and the coherence is higher for larger number of molecules. We also found that the power spectrum of autocorrelation functions show resonance peak at the frequency of coherent oscillations. The peak is less prominent for smaller number of molecules and less barrier height and therefore can be used as another measure of stability of oscillations. As a consequence of nonzero probability flux, we show that the three-point correlations from the time traces show irreversibility, providing a possible way to explore the flux from the observations. Furthermore, we explored the escape time from the oscillation ring to outside at different molecular number. We found that when barrier height is higher, escape time is longer and phase coherence of oscillation is higher. Finally, we performed the global sensitivity analysis of the underlying parameters to find the key network wirings responsible for the stability of the oscillation system.     

Silverleaf nightshade,Solarium elaeagnifolium,origin, distribution,and relation to man

Silverleaf nightshade (Solanum elaeagnifolium) is a perennial weed that has become increasingly troublesome over the past several decades. Extensive use of soil-applied herbicides, accompanied by a reduction in annual weed competition and reduced tillage, have contributed to its spread and establishment as a serious pest. Crop plants are affected directly via competition and allelopathy or indirectly as the nightshade plants serve as hosts for destructive phytophagous insects or fungal pathogens. Probably native to the southwestern United States and northern Mexico,S. elaeagnifolium is now found in many semiarid regions of the world. Plants were used by the Pima, Kiowa and Navajo Indians in the preparation of food and in the tanning of leather. Containing the toxic glycoalkaloids solanine and solasonine, plants can cause livestock poisonings. The fruits, however, are a source of solasodine, which is used in the commercial manufacture of steroidal hormones.     

Allophycocyanin: trimers,monomers, subunits,and homodimers

Allophycocyanin is a photosynthetic light-harvesting pigment-protein complex located in the phycobilisomes of cyanobacteria and red algae. Using dynamic light scattering and circular dichroism, solutions of purified allophycocyanin were shown to consist of homogeneous trimers (alpha3beta3) with a nonspherical shape over a very wide range of protein concentrations at pH 6.0 and 20 degrees C. Deconvolutions of the visible circular dichroism spectrum of the trimer were carried out for the first determination of the individual spectra of all six-component chromophores. The chromophores were shown to be in different microenvironments that helped determine the spectrum of the trimer. Monomers (alpha beta) that were formed in either the presence of 0.50M NaSCN or at 45 degrees C were shown to be completely reversible to trimers. However, subunits (alpha and beta) that were formed in either the presence of 8M urea or at 60 degrees C, using spectroscopy and gel-filtration column chromatography, were observed to only partially reconstitute trimers. Homodimers (alpha2 and/or beta2) formed during the regeneration of trimers. The homodimer, which was detected for the first time when both subunits were present, was shown to be in equilibrium with its subunits. Unlike the trimer situation, subunits were found to fully reconstitute monomers in the presence of 0.50M NaSCN. These results suggest a route to trimer assembly from subunits with monomers serving as intermediaries and the homodimers forming in a nonproductive step that did not interfere with the overall assembly scheme.     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.