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Sample records for endogenous zinc content

  1. INTESTINAL EXCRETION OF ENDOGENOUS ZINC IN GUATEMALAN SCHOOL CHILDREN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The intestine is the major route of excretion of endogenous zinc and has a key role in maintaining zinc homeostasis. Phytate has been reported to increase these losses. Objective: To determine the rate of excretion of endogenous zinc in school-aged children in a poor rural community for ...

  2. Zinc content of selected foods.

    PubMed

    Freeland, J H; Cousins, R J

    1976-06-01

    The zinc content of 174 foods was determined by atomic absorption spectrophotometry, using a dry ash preparation method. Data on some of the foods were not available elsewhere. Shellfish, cheese, meats, and nuts represented the highest sources of zinc found in this study. Soft drinks and other beverages, as well as vegetables generally, were poor sources of zinc. PMID:1270715

  3. The role of the endogenous opiates in zinc deficiency anorexia.

    PubMed

    Essatara, M B; Morley, J E; Levine, A S; Elson, M K; Shafer, R B; McClain, C J

    1984-03-01

    Anorexia is a major symptom of zinc deficiency, but the mechanism(s) for this anorexia are poorly defined. Recent studies have suggested an integral role for endogenous opiate peptides in appetite regulation. Dynorphin, a leucine-enkephalin containing opiate peptide, is a potent inducer of spontaneous feeding. In this study we showed that zinc deficient animals were relatively resistant to dynorphin-induced feeding. Measurement of dynorphin levels using a highly sensitive radioimmunoassay showed that zinc deficient animals had lower levels of dynorphin in the hypothalamus than did ad lib fed animals, with weight restricted animals having intermediate values. [3H]-naloxone binding was significantly increased to isolated brain membranes from zinc deficient animals using 1 nM unlabeled naloxone when compared to ad lib fed controls with the weight restricted animals again having intermediate values. These data suggest that abnormalities in endogenous opiate regulation of appetite may well play a role in the anorexia of zinc deficiency. The effects of zinc deficiency on endogenous opiate action appear to include alterations in receptor affinity, a post-receptor defect and alterations in the synthesis and/or release of dynorphin. PMID:6146993

  4. A model to produce pure zinc deficiency in rats and its use to demonstrate that dietary phytate increases the excretion of endogenous zinc.

    PubMed

    Flanagan, P R

    1984-03-01

    An early effect of zinc deficiency in rats is loss of appetite with consequent malnourishment. To obviate the need for pair-feeding, rats were fed liquid semipurified diets by gastric tube feeding. Rats tube fed a zinc-deficient diet at a daily rate of 90-110 g/kg thrived for 6-7 days and then rapidly became seriously ill. In contrast rats fed the deficient diet ad libitum stopped growing after 3 days but remained relatively healthy. Animals tube fed a zinc-replete diet or the deficient diet with subcutaneous injections of zinc grew normally and suffered no ill effects. Rats tube fed the deficient diet and supplemented parenterally with zinc excreted significantly more endogenous zinc into small intestinal luminal washings and into feces than unsupplemented rats. Sodium phytate, added to the tube feed in three groups of rats fed the deficient diet and supplemented daily with 0, 0.33 and 3.3 mg Zn/kg, significantly increased the zinc content of luminal washings in all three groups, increased fecal zinc excretion in two groups and lowered body zinc levels, estimated by femur zinc, in two groups. Tube feeding provides a means to study: 1) pure zinc deficiency without malnourishment of other nutrients; and 2) the excretion of endogenous zinc into the gastrointestinal tract. PMID:6422015

  5. Rapid Mutation of Endogenous Zebrafish Genes Using Zinc Finger Nucleases Made by Oligomerized Pool ENgineering (OPEN)

    PubMed Central

    Maeder, Morgan L.; Reyon, Deepak; Sander, Jeffry D.; Peterson, Randall T.; Joung, J. Keith

    2009-01-01

    Background Customized zinc finger nucleases (ZFNs) form the basis of a broadly applicable tool for highly efficient genome modification. ZFNs are artificial restriction endonucleases consisting of a non-specific nuclease domain fused to a zinc finger array which can be engineered to recognize specific DNA sequences of interest. Recent proof-of-principle experiments have shown that targeted knockout mutations can be efficiently generated in endogenous zebrafish genes via non-homologous end-joining-mediated repair of ZFN-induced DNA double-stranded breaks. The Zinc Finger Consortium, a group of academic laboratories committed to the development of engineered zinc finger technology, recently described the first rapid, highly effective, and publicly available method for engineering zinc finger arrays. The Consortium has previously used this new method (known as OPEN for Oligomerized Pool ENgineering) to generate high quality ZFN pairs that function in human and plant cells. Methodology/Principal Findings Here we show that OPEN can also be used to generate ZFNs that function efficiently in zebrafish. Using OPEN, we successfully engineered ZFN pairs for five endogenous zebrafish genes: tfr2, dopamine transporter, telomerase, hif1aa, and gridlock. Each of these ZFN pairs induces targeted insertions and deletions with high efficiency at its endogenous gene target in somatic zebrafish cells. In addition, these mutations are transmitted through the germline with sufficiently high frequency such that only a small number of fish need to be screened to identify founders. Finally, in silico analysis demonstrates that one or more potential OPEN ZFN sites can be found within the first three coding exons of more than 25,000 different endogenous zebrafish gene transcripts. Conclusions and Significance In summary, our study nearly triples the total number of endogenous zebrafish genes successfully modified using ZFNs (from three to eight) and suggests that OPEN provides a reliable

  6. Zinc content of selected tissues and taste perception in rats fed zinc deficient and zinc adequate rations

    SciTech Connect

    Boeckner, L.S.; Kies, C.

    1986-03-05

    The objective of the study was to determine the effects of feeding zinc sufficient and zinc deficient rations on taste sensitivity and zinc contents of selected organs in rats. The 36 Sprague-Dawley male weanling rats were divided into 2 groups and fed zinc deficient or zinc adequate rations. The animals were subjected to 4 trial periods in which a choice of deionized distilled water or a solution of quinine sulfate at 1.28 x 10/sup -6/ was given. A randomized schedule for rat sacrifice was used. No differences were found between zinc deficient and zinc adequate rats in taste preference aversion scores for quinine sulfate in the first three trial periods; however, in the last trial period rats in the zinc sufficient group drank somewhat less water containing quinine sulfate as a percentage of total water consumption than did rats fed the zinc deficient ration. Significantly higher zinc contents of kidney, brain and parotid salivary glands were seen in zinc adequate rats compared to zinc deficient rats at the end of the study. However, liver and tongue zinc levels were lower for both groups at the close of the study than were those of rats sacrificed at the beginning of the study.

  7. A reduced phytate diet does not reduce endogenous fecal zinc in children on a habitual high-phytate diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ten Malawian children, ages 3 to 5 years, at risk for zinc deficiency and receiving a habitual maize-based high-phytate diet, received maize after phytate reduction for 40 days and had their endogenous fecal zinc (EFZ) measured using stable isotope techniques before and after phytate reduction. The ...

  8. Effects of zinc deficiency on endogenous antioxidant enzymes and lipid peroxidation in glomerular cells of normal and five-sixths nephrectomized rats.

    PubMed

    Chen, S M; Young, T K

    1998-11-01

    We evaluated the effects of zinc deficiency on the activities of endogenous antioxidant enzymes and lipid peroxidation in rat glomerular cells (GCs). Male Sprague-Dawley rats (n = 48) were fed a zinc-deficient diet and deionized distilled water for 1 week to induce zinc deficiency. Half of the rats (zinc-deficient group) continued on this diet for 4 weeks, and the other half (zinc-replete group) were maintained on the same diet but with zinc-supplemented water (150 mg/Lzinc sulfate solution). Half of each group underwent five-sixths nephrectomy, while the other half underwent a sham operation. Another 12 normal rats (controls) were fed standard rat chow (containing 23.4% protein and 70 ppm zinc) and drank deionized distilled water. The zinc-deficient rats, including sham and five-sixths nephrectomized rats, showed severe growth retardation and poor appetite. Their mean plasma zinc concentrations were half that of normal control rats, but their plasma copper concentration was significantly higher than that of the control rats. Zinc supplementation corrected the abnormality of plasma zinc and copper concentrations and the loss of body weight in zinc-deficient rats. Zinc-deficient rats exhibited lower renal creatinine clearance and higher GC-malondialdehyde (GC-MDA) than zinc-replete rats. The remnant kidney of all five-sixths nephrectomized rats, including zinc-deficient and zinc-replete rats, showed a compensatory elevation in renal creatinine clearance and increased GC-MDA concentrations. Zinc concentrations in the renal cortex were decreased in zinc-deficient rats and the activities of GC-superoxide dismutase and GC-glutathione peroxidase were increased, while zinc-replete rats exhibited normal activities of GC-superoxide dismutase and GC-glutathione peroxidase. We suggest that zinc deficiency enhances the formation of reactive oxygen species but does not affect the activities of endogenous antioxidant enzymes in glomerular cells. PMID:9872031

  9. Stability and broad-sense heritability of mineral content in potato: zinc

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mineral content of potato is an important consideration in the evaluation of its role in the human diet. Zinc content is vital due to its crucial role as a micronutrient. Zinc deficiency occurs among the poorest of the world’s populations. In this study36 breeding lines and varieties divid...

  10. Endogenous reactive oxygen species content and modulation of tyrosine phosphorylation during sperm capacitation.

    PubMed

    Donà, G; Fiore, C; Tibaldi, E; Frezzato, F; Andrisani, A; Ambrosini, G; Fiorentin, D; Armanini, D; Bordin, L; Clari, G

    2011-10-01

    Generation of controlled amounts of reactive oxygen species (ROS) and phosphorylation of protein tyrosine (Tyr) residues are two main cellular changes involved in sperm capacitation. This study examined the relationship between tyrosine-phosphorylation (Tyr-P) and endogenous ROS production during sperm capacitation, and correlated them with both sperm motility and functionality expressed as acrosome-reacted cells. Immediate ROS generation was observed to peak after a 45-min incubation, followed by a rapid decrease in ROS content and successive regeneration of the ROS peak in 3 h and later. These two peaks were directly correlated with both the Tyr-P process involving sperm heads and tails, and the acrosome reaction (69 ± 8% and 65 ± 4%, respectively). The period of low-ROS content resulted in low Tyr-P patterns, located exclusively in the cell midpiece, and drastic reduction in acrosome-reacted cells. Ascorbic acid addition inhibited both Tyr-P patterns and acrosome reactions, whereas NADPH induced high ROS generation, with Tyr-P patterns located only on sperm tails, and prevented the acrosome reaction. Sperm hyperactivation was insensitive to ROS content. This is an important parameter for evaluation of sperm capacitation, which is achieved only when both ROS generation reaches a peak and Tyr-P involves the sperm head. PMID:20738429

  11. Reverse Transcriptase: Correlation of Zinc Content with Activity

    PubMed Central

    Poiesz, Bernard J.; Seal, Gita; Loeb, Lawrence A.

    1974-01-01

    Evidence is presented that DNA polymerase of avian myeloblastosis virus has an obligatory zinc requirement for activity. Previous studies indicate that the purified polymerase contains zinc in a stoichiometry of about 1 g-atom/mole. We now find that the enzyme-bound zinc is exchangeable with radioactive 65Zn; after isoelectric focusing, the radioactive 65Zn is coincident with polymerase activity. Dialysis of the 65Zn-labeled polymerase against the chelator, 1,10-phenanthroline, results in a progressive loss of radioactive 65Zn and polymerase activity. Thereupon, incubation of the inactivated enzyme with Zn2+ fully restores activity. Thus, the DNA polymerase present in an oncogenic RNA virus, like animal DNA polymerases, can be rigorously classified as a zinc metalloenzyme. DNA polymerase of avian myeloblastosis virus is inactivated by 1,10-phenanthroline at a much faster rate than the bacterial and animal DNA polymerases that have been tested. It may, therefore, be possible to inactivate selectively DNA polymerases from animal tumor viruses by brief exposure to appropriate metal chelators. PMID:4140513

  12. ZINC

    EPA Science Inventory

    This report summarizes the available information on zinc as it relates to its effects on man and his environment. Zinc is found in most soils, but some areas are deficient in it. Metallurgic operations contribute to zinc contamination in air, water and soil. Trace amounts of zinc...

  13. Content of Zinc and Copper in Selected Plants Growing Along a Motorway.

    PubMed

    Malinowska, Elżbieta; Jankowski, Kazimierz; Wiśniewska-Kadżajan, Beata; Sosnowski, Jacek; Kolczarek, Roman; Jankowska, Jolanta; Ciepiela, Grażyna A

    2015-11-01

    In 2011 a study was carried out analyzing the effects of road traffic on bioaccumulation of zinc and copper in selected species of dicotyledonous plants growing on adjacent grasslands. To do the research the plants were sampled from the 9-km-long Siedlce bypass, a part of the international route E-30. They were collected during the flowering stage, at following distances from the road: 1, 5, 10, 15 m. The content of zinc and copper was determined with the AAS method, with dry mineralisation done before. The highest concentration of the elements, regardless of the distance from the road, was found in Taraxacum spec. Among the tested plants, the lowest zinc content was in Vicia cracca, and the lowest copper content in Rumex acetosa. The limit for copper content was exceeded in Taraxacum spec. and, slightly, in Achillea millefolium growing at the roadside, closest to the roadway. PMID:26364030

  14. Modulation of GABA-mediated synaptic transmission by endogenous zinc in the immature rat hippocampus in vitro.

    PubMed Central

    Xie, X; Hider, R C; Smart, T G

    1994-01-01

    1. Intracellular recordings from postnatal 2- to 12-day-old (P2-12) rat hippocampal CA3 pyramidal neurones exhibited spontaneous synaptic potentials mediated by GABAA receptors. These potentials can be separated on the basis of amplitude into two classes which are referred to as small and large. 2. The large depolarizing potentials were reversibly inhibited by the Zn2+ chelator 1,2-diethyl-3-hydroxypyridin-4-one (CP94). The small inhibitory postsynaptic potentials. (IPSPs) were apparently unaffected. 3. Stimulation of the mossy fibre pathway evoked composite excitatory postsynaptic potentials (EPSPs) and IPSPs. Threshold stimulus-evoked synaptic potentials were mediated by GABAA receptors and were reversibly blocked by CP94. The responses evoked by suprathreshold stimulation and persisting in the presence of bicuculline or CP94 were partially inhibited by 2-amino-5-phosphonopropionic acid (AP5) and were completely blocked with 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). 4. L-Histidine, which preferentially forms complexes with Cu2+ > Zn2+ > Fe2+ > Mn2+, inhibited both naturally occurring spontaneous and evoked GABAA-mediated large synaptic potentials without affecting the neuronal resting membrane properties. Exogenously applied Zn2+ induced large spontaneous synaptic potentials and prolonged the duration of the evoked potentials. These effects were reversibly blocked by histidine. 5. The metal chelating agent diethyldithiocarbamate had little effect on the large amplitude synaptic potentials. 6. The transition metal divalent cations Fe2+ and Mn2+ did not initiate large synaptic potentials in CA3 neurones; however, Cu2+ depolarized the membrane and enhanced both excitatory and inhibitory synaptic transmission, resulting in a transient increase in the frequency of the large amplitude events. In comparison, zinc increased the frequency of the large potentials and also induced such events in neurons (P4-21) where innate potentials were absent. The postsynaptic

  15. Zinc

    MedlinePlus

    ... Guidelines for Americans and the U.S. Department of Agriculture's MyPlate . Where can I find out more about ... on food sources of zinc: U.S. Department of Agriculture's (USDA’s) National Nutrient Database Nutrient List for zinc ( ...

  16. Zinc

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

  17. Spatio-temporal changes in endogenous abscisic acid contents during etiolated growth and photomorphogenesis in tomato seedlings

    PubMed Central

    Humplík, Jan F; Turečková, Veronika; Fellner, Martin; Bergougnoux, Véronique

    2015-01-01

    The role of abscisic acid (ABA) during early development was investigated in tomato seedlings. The endogenous content of ABA in particular organs was analyzed in seedlings grown in the dark and under blue light. Our results showed that in dark-grown seedlings, the ABA accumulation was maximal in the cotyledons and elongation zone of hypocotyl, whereas under blue-light, the ABA content was distinctly reduced. Our data are consistent with the conclusion that ABA promotes the growth of etiolated seedlings and the results suggest that ABA plays an inhibitory role in de-etiolation and photomorphogenesis in tomato. PMID:26322576

  18. Zinc

    MedlinePlus

    ... women taking iron and folic acid supplements. Prostate cancer. Early research suggests that taking zinc along with other vitamins and minerals may prevent prostate cancer in some men. However, other research suggests that ...

  19. Zinc

    MedlinePlus

    ... by mouth does not improve sperm count or sperm movement in men with fertility problems. However, other early research suggests that zinc supplementation increases sperm count, testosterone levels, and pregnancy rates in infertile ...

  20. Photic Injury to Cultured RPE Varies Among Individual Cells in Proportion to Their Endogenous Lipofuscin Content as Modulated by Their Melanosome Content

    PubMed Central

    Zareba, Mariusz; Skumatz, Christine M. B.; Sarna, Tadeusz J.; Burke, Janice M.

    2014-01-01

    Purpose. We determined whether photic stress differentially impairs organelle motility of RPE lipofuscin and melanin granules, whether lethal photic stress kills cells in proportion to lipofuscin abundance, and whether killing is modulated by melanosome content. Methods. Motility of endogenous lipofuscin and melanosome granules within the same human RPE cells in primary culture was quantified by real-time imaging during sublethal blue light irradiation. Cell death during lethal irradiation was quantified by dynamic imaging of the onset of nuclear propidium iodide fluorescence. Analyzed were individual cells containing different amounts of autofluorescent lipofuscin, or similar amounts of lipofuscin and a varying content of phagocytized porcine melanosomes, or phagocytized black latex beads (control for light absorbance). Results. Lipofuscin granules and melanosomes showed motility slowing with mild irradiation, but slowing was greater for lipofuscin. On lethal irradiation, cell death was earlier in cells with higher lipofuscin content, but delayed by the copresence of melanosomes. Delayed death did not occur with black beads, suggesting that melanosome protection was due to properties of the biological granule, not simple screening. Conclusions. Greater organelle motility slowing of the more photoreactive lipofuscin granule compared to melanosomes suggests that lipofuscin mediates mild photic injury within RPE cells. With lethal light stress endogenous lipofuscin mediates killing, but the effect is cell autonomous and modulated by coincident melanosome content. Developing methods to quantify the frequency of individual cells with combined high lipofuscin and low melanosome content may have value for predicting the photic stress susceptibility of the RPE monolayer in situ. PMID:25034597

  1. Investigation on the heavy-metal content of zinc-air button cells.

    PubMed

    Richter, Andrea; Richter, Silke; Recknagel, Sebastian

    2008-01-01

    Within the framework of a German government project (initiated by the Federal Environment Agency) to check the compliance of commercially available batteries with the German Battery Ordinance concerning their heavy metal contents, 18 different types of commercially available zinc-air button cells were analysed for their cadmium, lead and mercury contents. After microwave assisted dissolution with aqua regia, Cd and Pb were determined using inductively coupled plasma mass spectrometry (ICP-MS), and Hg was determined using inductively coupled plasma optical emission spectrometry (ICP OES) and atomic absorption spectrometry. Cd contents were found to be much lower than the permitted limits; Pb contents were also found to be below the limits. Hg contents were found to be near the limits, and in one case the limit was exceeded. PMID:18280730

  2. Calcium, magnesium, copper and zinc content of menu components: comparison of analysed with calculated values.

    PubMed

    Ekmekcioglu, C; Anderle, H; Strauss-Blasche, G; Steffan, I; Feyertag, J; Marktl, W

    1999-10-01

    The objective of this study was to show whether analysed nutrient data correlate with calculated values from a food database. For this purpose the calcium, magnesium, copper and zinc contents of 62 menu components from lunch menus were determined with ICP-AES. Then the analysed values were compared with calculated values from a widely used food database. Our results indicated that there is a significant correlation (p < 0.01) between the analysed and calculated values of all four elements. The correlation coefficient as determined with nonparametric correlation analysis was 0.807 for calcium, 0.786 for magnesium, 0.772 for zinc, and 0.414 for copper. Although these correlations are significant, great differences between analysed and calculated values for all four elements could be found when considering single menu components. Therefore data of studies illustrating analysed with calculated values of single menu components have practical importance. PMID:10555297

  3. [Zinc].

    PubMed

    Couinaud, C

    1984-10-01

    Zinc is indispensable for life from bacteria to man. As a trace element it is included in numerous enzymes or serves as their activator (more than 80 zinc metallo-enzymes). It is necessary for nucleic acid and protein synthesis, the formation of sulphated molecules (insulin, growth hormone, keratin, immunoglobulins), and the functioning of carbonic anhydrase, aldolases, many dehydrogenases (including alcohol-dehydrogenase, retinal reductase indispensable for retinal rod function), alkaline phosphatase, T cells and superoxide dismutase. Its lack provokes distinctive signs: anorexia, diarrhea, taste, smell and vision disorders, skin lesions, delayed healing, growth retardation, delayed appearance of sexual characteristics, diminished resistance to infection, and it may be the cause of congenital malformations. Assay is now simplified by atomic absorption spectrophotometry in blood or hair. There is a latent lack prior to any disease because of the vices of modern eating habits, and this increases during stress, infections or tissue healing processes. Its lack is accentuated during long-term parenteral feeding or chronic gastrointestinal affections. Correction is as simple as it is innocuous, and zinc supplements should be given more routinely during surgical procedures. PMID:6210294

  4. Genetic variability for iron and zinc content in common bean lines and interaction with water availability.

    PubMed

    Pereira, H S; Del Peloso, M J; Bassinello, P Z; Guimarães, C M; Melo, L C; Faria, L C

    2014-01-01

    The common bean is an important source of iron and zinc in humans. Increases in the contents of these minerals can combat mineral deficiencies, but these contents are influenced by environmental conditions. Thus, the objectives of this study were to investigate the interaction between common bean lines and water availability on iron and zinc contents (CFe and CZn, respectively), identify superior lines with stable CFe and CZn, and test for a genetic relationship between CFe and CZn. Six crop trials were performed using a randomized block design with three replications. The trials were performed during the winter sowing period for three different combinations of year and site in Brazil. For each combination, 53 lines were evaluated across two parallel trials; one trial was irrigated according to the crop requirements, and the other trial operated under a water deficit. Interaction was detected between lines and environments, and between lines and water availability for CFe and CZn. However, some lines exhibited high CFe and CZn in both conditions. Lines G 6492 and G 6490 exhibited high mean values, stability, and adaptability for both minerals. Other lines exhibited high CFe (Xamego) or CZn (Bambuí and Iapar 65). A moderate genetic correlation (0.62) between CFe and CZn was detected. Water availability during the common bean cycle had an effect on CFe and CZn; however, lines with high CFe and CZn in different conditions of water availability and environment were detected. PMID:25177957

  5. Temperature Regulation of Growth and Endogenous Abscisic Acid-like Content of Tulipa gesneriana L

    PubMed Central

    Aung, Louis H.; De Hertogh, August A.

    1979-01-01

    The ontogenetic changes of dry matter and abscisic acid (ABA)-like content in the component organs of Tulipa gesneriana L. `Paul Richter' and `Golden Melody' under two temperature storage regimes were determined. The organ dry matter and ABA showed marked differences during 13 and 5 C dry storage and during subsequent growth at 13 C. Scale dry matter of both cultivars declined sharply when grown at 13 C. The basalplate of the cultivars showed an initial gain in dry matter, but declined subsequently. The shoot of both cultivars stored at 13 C exhibited greater dry matter gain than at 5 C. In contrast, the bulblets of the cultivars at 5 C showed a much higher rate of dry matter accumulation than at 13 C. An inhibitory substance extracted from tulip bulb organs co-chromatographed with authentic ABA and had identical thin layer chromatographic RF values of ABA in five solvent systems. The total ABA content per bulb increased 3-fold in `Golden Melody' and 2- to 4-fold in `Paul Richter' during the course of the temperature treatments. ABA was low in the scales and shoot, but it was high in the basalplate, bulblets, and roots. It is suggested that the probable ABA biosynthetic sites of tulip bulb are the developing bulblets, basalplate, and roots. PMID:16660867

  6. FT-IR study of the effect of zinc exposure on the biochemical contents of the muscle of Labeo rohita

    NASA Astrophysics Data System (ADS)

    Palaniappan, PL. RM.; Renju, V. B.

    2009-01-01

    Heavy metal pollution is a major environmental problem in the modern world due to increasing human activities. Zinc is an essential element involved in a wide variety of cellular processes. However, it becomes toxic when elevated concentrations are introduced into the environment. The goal of the present study is to investigate the effect of zinc exposure on the biochemical contents of the muscle tissues of freshwater species Labeo rohita using Fourier transform infrared (FT-IR) spectroscopy. Since the muscle constitutes the greatest mass of the fish that is consumed, the present study has paid particular attention to muscle component. The result reveals that the zinc exposure causes significant changes in the biochemical contents of the L. rohita muscle tissues. In addition, it causes an alteration in the protein secondary structures by decreasing the α-helix and increasing the β-sheet contents of muscle tissues. Further, it has been observed that the administration of chelating agent D-penicillamine improves the protein and lipid contents in the muscle tissues compared to zinc exposed tissues. This result shows that D-penicillamine is the effective chelator of zinc in reducing the body burden of L. rohita fingerlings.

  7. Endogenous nitric oxide in Pseudomonas fluorescens ZY2 as mediator against the combined exposure to zinc and cefradine.

    PubMed

    Xu, Yan-Bin; Zhou, Yan; Ruan, Jing-Jing; Xu, Shi-Hui; Gu, Ji-Dong; Huang, Shao-Song; Zheng, Li; Yuan, Bao-Hong; Wen, Li-Hua

    2015-05-01

    A better understanding on the mechanism involved in bacterial resistance to combined exposure to antibiotics and heavy metals is helpful in implementing practices to mitigate their ecological risk and spread of resistance genes in microbial population. Pseudomonas fluorescens ZY2, a strain isolated from swine wastewater, was chosen to study its growth (bacterial density OD600), the formation of reactive oxygen species (ROS), nitric oxide (NO) and NO synthases (NOS) under Zn, cefradine or Zn + cefradine treatments. Using Zn and cefradine as representative heavy metal and antibiotic in this investigation, respectively, the resistance of P. fluorescens ZY2 to toxic chemical exposure was investigated. Bacterial densities of treatment groups significantly increased over the time of incubation, but less than the control. ROS, NO and NOS initially increased, but then decreased after the initial 8 h of culturing, and were positively related to Zn concentrations. Moreover, the formation of ROS, NOS, and NO was activated by cefradine at Zn of up to 160 mg/L, but inhibited at Zn of 200 mg/L whether cefradine was added or not. Zn concentration affected ROS and NO concentrations between treatments and also was closely related to the variation of the relative bacterial density. For P. fluorescens ZY2, the mediation of endogenous NO to overcome ROS in response to the combined exposure of Zn and cefradine was suggested as a co-resistance mechanism, which would be beneficial to evaluate the ecological risk of heavy metals and antibiotics. PMID:25678231

  8. The effects of dormancy status on the endogenous contents and biological activities of jasmonic acid, n-(jasmonoyl)-isoleucine, and tuberonic acid in potato tubers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of storage and dormancy progression on the endogenous contents and the growth-regulating activities of jasmonic acid (JA), jasmonoyl-isoleucine (JA-Ile), and tuberonic acid (TA) were determined in potato (Solanum tuberosum L. cv. Russet Burbank) minitubers and seed tubers over several ha...

  9. Strontium and Zinc Content in Bones as an Indication of Diet: An Undergraduate Project in Quantitative Analysis with Interdisciplinary Interest.

    ERIC Educational Resources Information Center

    Rheingold, Arnold L.; And Others

    1983-01-01

    Background information and procedures are provided for experiments in which the zinc and strontium content in bones (fossils and/or fresh mammalian samples) is analyzed to determine relative amounts of animal and vegetable foods consumed by an individual during its lifetime. (JN)

  10. Effects of cooking methods on the iron and zinc contents in cowpea (Vigna unguiculata) to combat nutritional deficiencies in Brazil

    PubMed Central

    Pereira, Elenilda J.; Carvalho, Lucia M. J.; Dellamora-Ortiz, Gisela M.; Cardoso, Flávio S. N.; Carvalho, José L. V.; Viana, Daniela S.; Freitas, Sidinea C.; Rocha, Maurisrael M.

    2014-01-01

    Background Because iron deficiency anemia is prevalent in developing countries, determining the levels of iron and zinc in beans, the second most consumed staple food in Brazil, is essential, especially for the low-income people who experience a deficiency of these minerals in their diet. Objectives This study aimed to evaluate the effect of cooking methods by measuring the iron and zinc contents in cowpea cultivars before and after soaking to determine the retention of these minerals. Methods The samples were cooked in both regular pans and pressure cookers with and without previous soaking. Mineral analyses were carried out by Spectrometry of Inductively Coupled Plasma (ICP). Results The results showed high contents of iron and zinc in raw samples as well as in cooked ones, with the use of regular pan resulting in greater percentage of iron retention and the use of pressure cooker ensuring higher retention of zinc. Conclusions The best retention of iron was found in the BRS Aracê cultivar prepared in a regular pan with previous soaking. This cultivar may be indicated for cultivation and human consumption. The best retention of zinc was found for the BRS Tumucumaque cultivar prepared in a pressure cooker without previous soaking. PMID:24624050

  11. Redox-Active Sensing by Bacterial DksA Transcription Factors Is Determined by Cysteine and Zinc Content

    PubMed Central

    Crawford, Matthew A.; Tapscott, Timothy; Fitzsimmons, Liam F.; Liu, Lin; Reyes, Aníbal M.; Libby, Stephen J.; Trujillo, Madia; Fang, Ferric C.; Radi, Rafael

    2016-01-01

    ABSTRACT The four-cysteine zinc finger motif of the bacterial RNA polymerase regulator DksA is essential for protein structure, canonical control of the stringent response to nutritional limitation, and thiol-based sensing of oxidative and nitrosative stress. This interdependent relationship has limited our understanding of DksA-mediated functions in bacterial pathogenesis. Here, we have addressed this challenge by complementing ΔdksA Salmonella with Pseudomonas aeruginosa dksA paralogues that encode proteins differing in cysteine and zinc content. We find that four-cysteine, zinc-bound (C4) and two-cysteine, zinc-free (C2) DksA proteins are able to mediate appropriate stringent control in Salmonella and that thiol-based sensing of reactive species is conserved among C2 and C4 orthologues. However, variations in cysteine and zinc content determine the threshold at which individual DksA proteins sense and respond to reactive species. In particular, zinc acts as an antioxidant, dampening cysteine reactivity and raising the threshold of posttranslational thiol modification with reactive species. Consequently, C2 DksA triggers transcriptional responses in Salmonella at levels of oxidative or nitrosative stress normally tolerated by Salmonella expressing C4 orthologues. Inappropriate transcriptional regulation by C2 DksA increases the susceptibility of Salmonella to the antimicrobial effects of hydrogen peroxide and nitric oxide, and attenuates virulence in macrophages and mice. Our findings suggest that the redox-active sensory function of DksA proteins is finely tuned to optimize bacterial fitness according to the levels of oxidative and nitrosative stress encountered by bacterial species in their natural and host environments. PMID:27094335

  12. Tooth hardness increases with zinc-content in mandibles of young adult leaf-cutter ants.

    PubMed

    Schofield, Robert M S; Nesson, Michael H; Richardson, Kathleen A

    2002-12-01

    A wide variety of arthropods and members of other phyla have elevated concentrations of Zn, Mn, other heavy metals and halogens in their jaws, leg claws, and other "tools" for interacting with the environment. While measured Zn concentrations reach 25% of dry mass in scorpion stings, concentrations are often lower than this and the enriched structures are not heavily biomineralized like vertebrate teeth and the radula of mollusks. For this reason, the degree to which the inorganic components of these structures modify their mechanical properties is in question. Here we address this problem by measuring hardness during the development of Zn accumulations in ant mandibles. We found that Zn is incorporated into the mandibular teeth of leaf-cutter ants during early adult life, reaching concentrations of about 16% of dry mass. We show that the hardness of the mandibular teeth increases nearly three-fold as the adults age and that hardness correlates with Zn content ( r=0.91). We suggest that young adults rarely cut leaves partly because their mandibles are not yet rich in Zn. Zinc enrichment (along with enrichment by other heavy metals and halogens) may play an unrecognized role in the behavioral ecology and evolution of a wide variety of invertebrates. PMID:12536282

  13. Zinc content of commercial diluents widely used in drug admixtures prepared for intravenous infusion.

    PubMed

    Desai, Narendra R; Shah, Syed M; Koczone, Julianna; Vencl-Joncic, Maja; Sisto, Christopher; Ludwig, Stephen A

    2007-01-01

    During ongoing quality improvement efforts with two Wyeth parenteral products, Protonix and Zosyn, we noted that dosing solutions prepared from the products yielded inconsistent results on the United States Pharmacopeia Chapter 788 test for subvisible particulates. This manuscript discusses variables that have a direct impact on intravenous products meeting compendial monograph specifications under conditions that are encountered in the clinical setting. The rubber stoppers of vials used for parenteral products, different parts of commercial admixture bags, and the tubing of the administration sets and devices contain residual amounts of metal ions, plasticizers, and other additives incorparated for specific functions. The transition metal ions, including zinc and copper, may leach into drug products during manufacture and during storage of dosing admixture bags prepared for infusion in hospital pharmacies or clinics. The metal ions may compromise the quality of the infusion admixture through catalytic drug degradation and/or generation of undesirable metal ion complexes, which may convert soluble drug molecules into insoluble particulates. To preserve the quality of the drug product, it is essential that metal ion leachables be controlled proactively during manufacture of the drug product; knowledge of metal ion contents in the commercial diluents use for reconstitution, admixture preparation, and flushing of the administration lines is also critical. PMID:23969523

  14. Determination of hydroxide and carbonate contents of alkaline electrolytes containing zinc

    NASA Technical Reports Server (NTRS)

    Otterson, D. A.

    1975-01-01

    A method to prevent zinc interference with the titration of OH- and CO3-2 ions in alkaline electrolytes with standard acid is presented. The Ba-EDTA complex was tested and shown to prevent zinc interference with acid-base titrations without introducing other types of interference. Theoretical considerations indicate that this method can be used to prevent interference by other metals.

  15. Endogenous zinc depresses GABAergic transmission via T-type Ca2+ channels and broadens the time window for integration of glutamatergic inputs in dentate granule cells

    PubMed Central

    Grauert, Antonia; Engel, Dominique; Ruiz, Arnaud J

    2014-01-01

    Abstract Zinc actions on synaptic transmission span the modulation of neurotransmitter receptors, transporters, activation of intracellular cascades and alterations in gene expression. Whether and how zinc affects inhibitory synaptic signalling in the dentate gyrus remains largely unexplored. We found that mono- and di-synaptic GABAergic inputs onto dentate granule cells were reversibly depressed by exogenous zinc application and enhanced by zinc chelation. Blocking T-type Ca2+ channels prevented the effect of zinc chelation. When recording from dentate fast-spiking interneurones, zinc chelation facilitated T-type Ca2+ currents, increased action potential half-width and decreased spike threshold. It also increased the offset of the input–output relation in a manner consistent with enhanced excitability. In granule cells, chelation of zinc reduced the time window for the integration of glutamatergic inputs originating from perforant path synapses, resulting in reduced spike transfer. Thus, zinc-mediated modulation of dentate interneurone excitability and GABA release regulates information flow to local targets and hippocampal networks. PMID:24081159

  16. Influence of Vitamin C and Vitamin E on testicular zinc content and testicular toxicity in lead exposed albino rats

    PubMed Central

    2012-01-01

    Background Occupational and environmental exposures to lead remain a public health problem as lead alters physiological processes by inducing oxidative stress and mimicking divalent cations. This study was designed to investigate the effects of Vitamin C (VC) and Vitamin E (VE) on the reproductive function of lead exposed male rats. Experimental animals were exposed to oral doses of lead, VC and VE at 60 mg/kg body weight, 40 mg/kg body weight, and 150 mg/kg body weight respectively, while control animals received 0.9% saline solution. Oral administration spanned for six weeks after which changes in testicular redox status, lead deposition, testicular zinc content, serum androgen content, semen quality and testis histology were examined. Results There were significant (p < 0.05) increases in oxidative stress indices and testicular lead content. A significant (p < 0.05) depletion of zinc in the testis of lead exposed animals was also observed. Fluctuations were observed in androgen levels of lead treated animals with a significant increase (p < 0.05) in Serum follicle stimulating hormone (FSH) and testosterone (TT) content, while there was no significant change in luteinizing hormone (LH) content. Testicular tissue showed an alteration in its normal histology with degeneration of the seminiferous epithelium accompanied by a significant reduction (p < 0.05) in the number of luminal spermatozoa. A downgrade in the semen appearance and semen quality –sperm motility, morphology, and count was also observed after lead exposure. VC and VE treatment showed a significant (p < 0.05) reversal of the physiological alteration induced by lead. Conclusions Lead exposure resulted in a decline in the reproductive function of male rats by inducing oxidative stress, inhibiting enzymes and depleting testicular zinc contents. However, results clearly showed that VC and VE attenuated the deleterious impact of lead on the reproductive system. PMID:23241495

  17. Relationship between endogenous hormonal content and somatic organogenesis in callus of peach (Prunus persica L. Batsch) cultivars and Prunus persica×Prunus dulcis rootstocks.

    PubMed

    Pérez-Jiménez, Margarita; Cantero-Navarro, Elena; Pérez-Alfocea, Francisco; Le-Disquet, Isabel; Guivarc'h, Anne; Cos-Terrer, José

    2014-05-01

    The relationship between endogenous hormones content and the induction of somatic peach plant was studied. To induce multiple shoots from callus derived from the base of stem explants of the scion cultivars 'UFO-3', 'Flariba' and 'Alice Bigi', and the peach×almond rootstocks 'Garnem' and 'GF677', propagated plants were cultured on Murashige and Skoog salts augmented with 0.1mgL(-1) of indolebutyric acid, 1mgL(-1) of 6-benzylaminopurine and 3% sucrose. The highest regeneration rate was obtained with the peach×almond rootstocks. Endogenous levels of abscisic acid (ABA), indole-3-acetic acid (IAA), zeatin (Z), zeatin riboside (ZR), ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC), salicylic acid (SA), and jasmonic acid (JA) were analyzed in the organogenic callus. Lower levels of several hormones, namely Z, ZR, ABA, and ACC were found in the peach×almond rootstock compared to peach cultivars, while IAA and SA presented inconclusive returns. These results suggest that the difference in somatic organogenesis capacity observed in peach and peach×almond hybrids is markedly affected by the endogenous hormonal content of the studied genotypes. PMID:24709154

  18. [Effects of zinc- and iron deficiency on physiological indices, mineral contents, and leaf ultrastructure of Poncirus trifoliata].

    PubMed

    Xiao, Jia-Xin; Qi, Xiao-Xiao; Zhang, Shao-Ling

    2010-08-01

    By using hydroponics, this paper studied the physiological responses of trifoliate orange (Poncirus trifoliata) seedlings to the deficiency of zinc (0 micromol x L(-1) Zn2+) and/or iron (0 micromol x L(-1) Fe-EDTA). The deficiency of both Zn and Fe decreased the plant biomass and root viability, and increased the leaf-and root SOD activity significantly. Zinc deficiency increased the leaf-and root POD significantly, while Fe deficiency had an adverse effect. The root CAT activity increased significantly under Zn deficiency, but had less difference with the control under Fe deficiency. Fe- and Zn deficiency induced a significant decrease of root potassium (K), magnesium (Mg), and phosphorus (P) contents and of shoot K content, respectively, but resulted in a significant increase in the root- and shoot Zn and Cu contents and in the root Fe and Mn contents and shoot Mn content, respectively. Ultrastructural observation of leaf structure and chloroplast showed that under Fe deficiency, the organelle was damaged seriously, which was revealed by the vacuolization of chloroplast and mitochondria, vague chloroplast membrane and thylakoid lamella, drastic increase of platoglobuli number, and absence of starch grain in the chloroplast. Under Zn deficiency, the thylakoid lamella of chloroplast was loosely distributed with less lamella, but the platoglobuli number was increased. PMID:21043103

  19. Soil zinc content, groundwater usage, and prostate cancer incidence in South Carolina

    PubMed Central

    Burch, James B.; Hussey, Jim; Temples, Tom; Bolick-Aldrich, Susan; Mosley-Broughton, Catishia; Liu, Yuan; Hebert, James R.

    2010-01-01

    Background Prostate cancer (PrCA) incidence in South Carolina (SC) exceeds the national average, particularly among African Americans (AAs). Though data are limited, low environmental zinc exposures and down-regulation of prostatic zinc transporter proteins among AAs may explain, in part, the racial PrCA disparity. Methods Age-adjusted PrCA rates were calculated by census tract. Demographic data were obtained from the 1990 census. Hazardous waste site locations and soil zinc concentrations were obtained from existing federal and state databases. A geographic information system and Poisson regression were used to test the hypothesis that census tracts with reduced soil zinc concentrations, elevated groundwater use, or more agricultural or hazardous waste sites had elevated PrCA risks. Results Census tracts with high groundwater use and low zinc concentrations had higher PrCA rate ratios (RR: 1.270; 95% confidence interval: 1.079, 1.505). This effect was not more apparent in areas populated primarily by AAs. Conclusion Increased PrCA rates were associated with reduced soil zinc concentrations and elevated groundwater use, although this observation is not likely to contribute to SC’s racial PrCA disparity. Statewide mapping and statistical modeling of relationships between environmental factors, demographics, and cancer incidence can be used to screen hypotheses focusing on novel PrCA risk factors. PMID:18949566

  20. Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro.

    PubMed

    Uski, O; Jalava, P I; Happo, M S; Torvela, T; Leskinen, J; Mäki-Paakkanen, J; Tissari, J; Sippula, O; Lamberg, H; Jokiniemi, J; Hirvonen, M-R

    2015-04-01

    Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24h to different doses (15, 50,150 and 300 μg ml(-1)) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. PMID:25553547

  1. Thiol and metal contents in periphyton exposed to elevated copper and zinc concentrations: a field and microcosm study.

    PubMed

    Le Faucheur, Séverine; Behra, Renata; Sigg, Laura

    2005-10-15

    Phytochelatins are metal-binding polypeptides produced by algae under metal exposure. The aim of this study was to investigate the effects of metal concentration variations in natural systems on periphyton at the biochemical level by analyzing its intracellular thiol content, in particular phytochelatins. To that purpose, two field campaigns were conducted in a stream subject to an increase of dissolved metal concentrations (particularly Cu and Zn) during rain events, which results in an increase of their accumulation in periphyton. At background metal concentrations, several thiols were detectable in periphyton, namely, glutathione (GSH), gamma-glutamylcysteine (gammaGluCys), phytochelatins (PC2), and some unidentified thiols, U1 and U2. Glutathione and gammaGluCys contents were found to vary independently of the rain, as well as U1 and U2, whereas the phytochelatin content increased during the rain events. To investigate whether Cu or Zn may be responsible for this increase, microcosm experiments were carried out with natural water enriched with Cu, Zn, and Cd separately, and Cu and Zn in combination. In this study, GSH, PC2, and U1 were also detected, but not gammaGluCys. An increase in accumulated Cu content did not induce any changes in thiol content, whereas an increase of the Zn content induced a decrease in GSH content and an increase in phytochelatin content. Zinc rather than Cu may thus induce a phytochelatin content increase in periphyton in the field studies. Addition of Cu and Zn in combination also induced an increase in phytochelatin content. Cadmium was found to be the most effective inducer, with the production of larger phytochelatins (PC3-4). This study is the first one to report changes in thiol content in periphyton in response to an increase of the metal concentration in natural freshwaters. PMID:16295881

  2. Over-expression of the MxIRT1 gene increases iron and zinc content in rice seeds.

    PubMed

    Tan, Song; Han, Rui; Li, Peng; Yang, Guang; Li, Shuang; Zhang, Peng; Wang, Wei-Bing; Zhao, Wei-Zhong; Yin, Li-Ping

    2015-02-01

    Iron and zinc are essential in plant and human nutrition. Iron deficiency has been one of the causes of human mortality, especially in developing countries with high rice consumption. MxIRT1 is a ferrous transporter that has been screened from an iron-efficient genotype of the apple tree, Malus xiaojinensis Cheng et Jiang. In order to produce Fe-biofortified rice with MxIRT1 to solve the Fe-deficiency problem, plant expression vectors of pCAMBIA1302-MxIRT1:GFP and pCAMBIA1302-anti MxIRT1:GFP were constructed that led to successful production of transgenic rice. The transgenic plant phenotypes showed that the expression of endogenous OsIRT1 was suppressed by anti-MxIRT1 in antisense lines that acted as an opposing control, while sense lines had a higher tolerance under Zn- and Fe-deficient conditions. The iron and zinc concentration in T3 seeds increased by three times in sense lines when compared to the wild type. To understand the MxIRT1 cadmium uptake, the MxIRT1 cadmium absorption trait was compared with AtIRT1 and OsIRT1 in transgenic rice protoplasts, and it was found that MxIRT1 had the lowest Cd uptake capacity. MxIRT1 transgenic tobacco-cultured bright yellow-2 (BY-2) cells and rice lines were subjected to different Fe conditions and the results from the non-invasive micro-test technique showed that iron was actively transported compared to cadmium as long as iron was readily available in the environment. This suggests that MxIRT1 is a good candidate gene for plant Fe and Zn biofortification. PMID:25099285

  3. Effect of processing conditions on phytic acid, calcium, iron, and zinc contents of lime-cooked maize.

    PubMed

    Bressani, Ricardo; Turcios, Juan Carlos; Colmenares de Ruiz, Ana Silvia; de Palomo, Patricia Palocios

    2004-03-10

    Tortillas are made by cooking maize in a lime solution during variable times and temperatures, steeping the grain for up to 12 h, washing and grinding it to a fine dough, and cooking portions as flat cakes for up to 6 min. The effects of the main processing steps on the chemical composition, nutritive value, and functional and physicochemical characteristics have been areas of research. The present work evaluates the effect of lime concentration (0, 1.2, 2.4, and 3.6%) and cooking times (45, 60, and 75 min) on phytic acid retention of whole maize, its endosperm, and germ, as well as on the content of calcium, iron, and zinc on the same samples. The effects of steeping time and temperature and steeping medium on the phytic acid of lime-cooked maize were also studied. Finally, phytic acid changes from raw maize to tortilla were also measured. The results indicated that lime concentration and cooking time reduce phytic acid content in whole grain (17.4%), in endosperm (45.8%), and in germ (17.0%). Statistical analyses suggested higher phytic acid loss with 1.2% lime and 75 min of cooking. Cooking with the lime solution is more effective in reducing phytic acid than cooking with water. Steeping maize in lime solution at 50 degrees C during 8 h reduced phytic acid an additional 8%. The total loss of phytic acid from maize to tortilla was 22%. Calcium content increased in whole maize, endosperm, and germ with lime concentration and cooking and steeping times. The increase was higher in the germ than in the endosperm. The level, however, can be controlled if steeping of the cooked grain is conducted in water. Iron and zinc contents were not affected by nixtamalization processing variables but were affected in steeping. PMID:14995114

  4. Magnetic properties of zinc-blende Cd1-xFexS nanoparticles: Temperature and Fe-content dependence studies

    NASA Astrophysics Data System (ADS)

    Ghosh, Anirudha; Paul, Sanhita; Raj, Satyabrata

    2016-05-01

    Magnetic properties of zinc-blende Cd1-xFexS (x~0.0017-0.033) nanoparticles have been investigated at various temperature regimes and contents of Fe3+ ions. The high temperature (range: 160-300 K) inverse magnetic susceptibility has been found to follow linear Curie-Weiss equation for all compositions of samples with monotonic variation of Curie-Weiss temperature, Θ (from negative to positive values) with increase in Fe3+ content, which implies a transition from anti-ferromagnetic to ferromagnetic ordering. However, at low temperature regime (range: 5-70 K) anti-ferromagnetic ordering prevails in all compositions of samples but show changing trend from anti-ferromagnetic towards ferromagnetic with Fe content, similar to the high temperature regime. A particular content of Fe3+ ions in Cd1-xFexS is estimated by fitting Θ linearly as a function of x, where identical magnetic phases are expected in both low and high temperature regimes. The sample with such amount of Fe3+ ions content has been found to be weakly anti-ferromagnetic.

  5. Effects of heat stress on the endogenous contents of hormones and related gene expression in developing axillary tubes of potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potatoes are a cool season crop and optimum tuber initiation, development, yield, and quality require growing temperatures between 15 -20°C. At temperatures above 30°C, tuber initiation is delayed or prevented and developing tubers exhibit decreased starch content, increased malformation, chain-tube...

  6. Phytoremediation of cadmium improved with the high production of endogenous phenolics and free proline contents in Parthenium hysterophorus plant treated exogenously with plant growth regulator and chelating agent.

    PubMed

    Ali, Nasir; Hadi, Fazal

    2015-09-01

    Pot experiments were conducted to evaluate the effects of gibberellic acid (GA3) and ethylenediaminetetraacetic acid (EDTA) on growth parameters, cadmium (Cd) phytoextraction, total phenolics, free proline and chlorophyll content of Parthenium hysterophorus plant grown in Cd-contaminated (100 mg/kg) soil. GA3 was applied as foliar spray (10(-2), 10(-4) and 10(-6) M) while EDTA (40 mg/kg soil) was added to soil as single and in split doses. Results showed decrease in growth parameters due to Cd stress but P. hysterophorus plant demonstrated Cd hyperaccumulator potential based on bioconcentration factor (BCF). Lower concentration of GA3 (10(-6) M) showed highest significant increase in the growth parameters while Cd concentration, accumulation (1.97 ± 0.11 mg/DBM) and bioconcentration (9.75 ± 0.34) was significantly higher in the treatment T11 (GA3 10(-2) + split doses of EDTA). Cadmium significantly increased the root free proline while total phenolic concentration was significantly high in all parts of the plant. Chlorophyll contents were significantly reduced by Cd. GA3 showed significant increase in phenolic and chlorophyll contents in plant. Cadmium accumulation in plant tissues showed positive correlation with free proline (R (2) = 0.527, R (2) = 0.630) and total phenolics (R (2) = 0.554, R (2) = 0.723) in roots and leaves, respectively. Cd contents negatively correlated with biomass, chlorophyll and total water contents. Proline and phenolic contents showed positive correlation with dry biomass of plant. These findings suggest further investigation to study the role of endogenous phenolics and proline in heavy metal phytoremediation. PMID:25940488

  7. Grain Development Mutants of Barley ([alpha]-Amylase Production during Grain Maturation and Its Relation to Endogenous Gibberellic Acid Content).

    PubMed Central

    Green, L. S.; Faergestad, E. M.; Poole, A.; Chandler, P. M.

    1997-01-01

    Barley (Hordeum vulgare L. Himalaya) mutants with altered grain morphology were isolated to investigate whether defects in grain development, possibly involving gibberellins (GAs) and abscisic acid, would lead to altered patterns of [alpha]-amylase gene expression. Following treatment with sodium azide, 75 mutants, typically showing grain shriveling, were identified. At grain maturity 15 of the 75 mutants had higher [alpha]-amylase activities in shriveled grains compared with either phenotypically normal grains that developed on the same heterozygous plant or with grains of cv Himalaya. Studies of four of these mutants demonstrated increased levels of both high- and low-isoelectric point [alpha]-amylase isozymes midway through grain development. This category of mutant has been designated pga, for premature grain [alpha]-amylase. One such mutant (M326) showed an endosperm-determined inheritance pattern. When crossed into a (GA-deficient) dwarfing background there was a 10- to 20-fold reduction in [alpha]-amylase activity, suggesting a requirement for GA biosynthesis. Endogenous GAs and abscisic acid were quantified by combined gas chromatography-specific ion monitoring in normal and mutant grains of heterozygous M326 plants during the period of [alpha]-amylase accumulation. Mutant grains had significantly higher (5.8-fold) levels of the bioactive GA1 compared with normal grains but much lower (approximately 10-fold) levels of the 2[beta]-hydroxylated ("inactive") GAs, typical of developing barley grains (e.g. GA8, GA34, GA48). We propose that a reduced extent of 2[beta]-hydroxylation in the mutant grains results in an increased level of GA1, which is responsible for premature [alpha]-amylase gene expression. PMID:12223700

  8. Tobacco susceptibility to Potato virus Y(NTN) infection is affected by grafting and endogenous cytokinin content.

    PubMed

    Spoustová, Petra; Hýsková, Veronika; Müller, Karel; Schnablová, Renata; Ryšlavá, Helena; Čeřovská, Noemi; Malbeck, Jiří; Cvikrová, Milena; Synková, Helena

    2015-06-01

    Faster or stronger response to pathogen occurs if plants undergo prior priming. Cytokinins seem to be also involved in plant priming and in response to pathogens. Susceptibility to Potato virus Y(NTN) (PVY(NTN)) was studied in transgenic cytokinin overproducing (Pssu-ipt) tobacco and compared with nontransgenic plants. Since cytokinin overproduction inhibits development of plant roots and grafting overcomes this limitation, both types were grown as rooted and/or grafted plants to check also the effect of grafting. Control rooted tobacco (C), the most susceptible to PVY(NTN), showed always symptoms during the infection together with the rising virus content and a systemic response, such as accumulation of H2O2, salicylic acid (SA) and other phenolic acids, and stress-induced enzyme activities. In transgenic and grafted plants, the response to PVY(NTN) was dependent on protective mechanisms activated prior to the inoculation. In Pssu-ipt tobacco, cytokinin active forms and SA contents exceeded manifold their content in C. Grafting promoted the accumulation of phenolics, but SA, and stimulated peroxidase activities. Thus, the pre-infection barrier established in both transgenic and grafted plants helped to suppress partly the virus multiplication and resulted in milder symptom development. However, only the synergic effect of both grafting and the high cytokinins led to PVY(NTN) tolerance in transgenic grafts. Possible mechanisms were discussed. PMID:25900563

  9. Iron and zinc content of selected foods in the diet of schoolchildren in Kumi district, east of Uganda: a cross-sectional study

    PubMed Central

    2011-01-01

    Background Iron and zinc are essential micronutrients for humans and deficiency of the two elements is widespread in the world with the highest prevalence in less developed countries. There are few data on dietary intake of iron and zinc in Uganda, and no food composition table is available. There is hardly any widely published literature that clearly documents the quality of Ugandan children's diet. Thus information of both food intake and the concentration of these trace elements in local food ingredients are needed in order to assess daily intake. Methods The present study focused on the iron and zinc content in selected foods and intake of the micronutrients iron and zinc among schoolchildren in Kumi District, Uganda. Over a period of 4 weeks single 24-hour dietary recall interviews were carried out on a convenience sample of 178 schoolchildren (9-15 years old). Data from the dietary recalls was used when selecting foods for chemical analysis. Results Results from this study showed that the iron concentrations varied, and were high in some cereals and vegetables. The zinc concentrations in foods generally corresponded with results from other African countries (Mali and Kenya). Data from the 24-hour dietary recall showed that the daily Recommended Nutrient Intake (RNI) was met for iron but not for zinc. Conclusions The schoolchildren of Kumi district had a predominantly vegetable based diet. Foods of animal origin were consumed occasionally. The iron content in the selected foods was high and variable, and higher than in similar ingredients from Kenya and Mali, while the zinc concentrations were generally in accordance with reported values. The total daily zinc (mg) intake does not meet the daily RNI. The iron intake is adequate according to RNI, but due to iron contamination and reduced bioavailability, RNI may not be met in a vegetable based diet. More studies are needed to investigate possible sources of contamination. PMID:21827701

  10. Cumulative effect of heterologous AtWRI1 gene expression and endogenous BjAGPase gene silencing increases seed lipid content in Indian mustard Brassica juncea.

    PubMed

    Bhattacharya, Surajit; Das, Natasha; Maiti, Mrinal K

    2016-10-01

    The production of vegetable oil in many countries of the world, including India has not been able to keep pace with the increasing requirement, leading to a very large gap in the demand-supply chain. Thus, there is an urgent need to increase the yield potential of the oilseed crops so as to enhance the storage lipid productivity. The present study describes a novel metabolic engineering ploy involving the constitutive down-regulation of endogenous ADP-glucose pyrophosphorylase (BjAGPase) enzyme and the seed-specific expression of WRINKLED1 transcription factor (AtWRI1) from Arabidopsis thaliana in Indian mustard (Brassica juncea) with an aim to divert the photosynthetically fixed carbon pool from starch to lipid synthesis in the seeds for the enhanced production of storage lipids in the seeds of transgenic mustard plants. The starch content, in both the vegetative leaf and developing seed tissues of the transgenic B. juncea lines exhibited a reduction by about 45-53% compared to the untransformed control, whereas the soluble sugar content was increased by 2.4 and 1.3-fold in the leaf and developing seed tissues, respectively. Consequently, the transgenic lines showed a significant enhancement in total seed lipid content ranging between 7.5 and 16.9%. The results indicate that the adopted metabolic engineering strategy was successful in significantly increasing the seed oil content. Therefore, findings of our research suggest that the metabolic engineering strategy adopted in this study for shifting the anabolic carbon flux from starch synthesis to lipid biosynthesis can be employed for increasing the storage lipid content of seeds in other plant species. PMID:27314514

  11. MAS-NMR study of lithium zinc silicate glasses and glass-ceramics with various ZnO content

    SciTech Connect

    Goswami, Madhumita; Kothiyal, Govind P.; Montagne, Lionel Delevoye, Laurent

    2008-02-15

    Lithium zinc silicate glasses of composition (mol%): 17.5Li{sub 2}O-(72-x)SiO{sub 2}-xZnO-5.1Na{sub 2}O-1.3P{sub 2}O{sub 5}-4.1B{sub 2}O{sub 3}, 5.5{<=}x{<=}17.7, were prepared by conventional melt-quenched technique and converted to glass-ceramic by controlled crystallization process. {sup 29}Si and {sup 31}P MAS-NMR was used to characterize the structure of both glass and glass-ceramic samples. Despite the complex glass composition, Q{sup 2}, Q{sup 3} and Q{sup 4} sites are identified from {sup 29}Si MAS-NMR, which relative intensities are found to vary with the ZnO content, indicating a network depolymerization by ZnO. Moreover, well separated Q{sup 3} and Q{sup 4} resonances for low ZnO content indicates the occurrence of phase separation. From {sup 31}P MAS-NMR, it is seen that phosphorus is mainly present in the form of ortho-(Q{sup 0}) and pyro-phosphate (Q{sup 1}) structural units and variation of ZnO content did not have much effect on these resonances, which provides an additional evidence for phase separation in the glass. On conversion to glass-ceramics, lithium disilicate (Li{sub 2}Si{sub 2}O{sub 5}), lithium zinc ortho-silicate (Li{sub 3}Zn{sub 0.5}SiO{sub 4}), tridymite (SiO{sub 2}) and cristobalite (SiO{sub 2}) were identified as major silicate crystalline phases. Using {sup 29}Si MAS-NMR, quantification of these silicate crystalline phases is carried out and correlated with the ZnO content in the glass-ceramics samples. In addition, {sup 31}P spectra unambiguously revealed the presence of crystalline Li{sub 3}PO{sub 4} and (Na,Li){sub 3}PO{sub 4} in the glass-ceramics. - Graphical abstract: {sup 29}Si and {sup 31}P MAS-NMR analyses were carried out on multi-component Li{sub 2}O-SiO{sub 2}-ZnO-Na{sub 2}O-P{sub 2}O{sub 5}-B{sub 2}O{sub 3} glasses and glass-ceramics developed for sealing application. Structural data are reported, including phase separation process and quantification of amorphous and crystalline phases.

  12. The low-AGE content of low-fat vegan diets could benefit diabetics - though concurrent taurine supplementation may be needed to minimize endogenous AGE production.

    PubMed

    McCarty, Mark F

    2005-01-01

    Increased endogenous generation of advanced glycation endproducts (AGEs) contributes importantly to the vascular complications of diabetes, in part owing to activation of the pro-inflammatory RAGE receptor. However, AGE-altered oligopeptides with RAGE-activating potential can also be absorbed from the diet, and indeed make a significant contribution to the plasma and tissue pool of AGEs; this contribution is especially prominent when compromised renal function impairs renal clearance of AGEs. Perhaps surprisingly, foods rich in both protein and fat, and cooked at high heat, tend to be the richest dietary sources of AGEs, whereas low-fat carbohydrate-rich foods tend to be relatively low in AGEs. Conceivably, this reflects the fact that the so-called "AGEs" in the diet are generated primarily, not by glycation reactions, but by interactions between oxidized lipids and protein; such reactions are known to give rise to certain prominent AGEs, such as epsilonN-carboxymethyl-lysine and methylglyoxal. Although roasted nuts and fried or broiled tofu are relatively high in AGEs, low-fat plant-derived foods, including boiled or baked beans, typically are low in AGEs. Thus, a low-AGE content may contribute to the many benefits conferred to diabetics by a genuinely low-fat vegan diet. Nonetheless, the plasma AGE content of healthy vegetarians has been reported to be higher than that of omnivores - suggesting that something about vegetarian diets may promote endogenous AGE production. Some researchers have proposed that the relatively high-fructose content of vegetarian diets may explain this phenomenon, but there so far is no clinical evidence that normal intakes of fructose have an important impact on AGE production. An alternative or additional possibility is that the relatively poor taurine status of vegetarians up-regulates the physiological role of myeloperoxidase-derived oxidants in the generation of AGEs - in which case, taurine supplementation might be expected to

  13. Bioleaching of cobalt and zinc from pyrite ore in relation to calcitic gangue content.

    PubMed

    Baldi, F; Bralia, A; Riccobono, F; Sabatini, G

    1991-05-01

    Bioleaching of a pyrite ore containing high concentrations of cobalt (0.1%) and zinc (0.065%) was affected by small amounts of calcitic gangue (from 0.01 to 1.01%). Results from an air-lift percolator and from Erlenmeyer flask experiments show that a small percentage of calcite raises the pH and arrests the growth of the acidophilic bacterium Thiobacillus ferrooxidans. In percolator experiments, when calcite is completely removed by the continuous addition of small quantities of acid, and the pH of the liquor becomes acid, the micro-organism begins to grow and to bio-oxidize the pyrite ore. The growth of T. ferrooxidans shows different lag phase spans (from 13 to 190 days) depending on carbonate dissolution. The metals Fe, Zn and Co are released into the leaching solution together at different rates after a lag-time which depends on calcite concentrations in pyrite gangue. Metal ratios in the mineral bulk are different from those in the liquor, Zn dissolving 5 times more readily than Co. Bioleaching rates for metal removal from pyrite are higher in percolator (for Fe, from 5 to 15 mg/l/h) than in flask experiments (from 0.5 to 2 mg/l/h), but the lag phases are shorter (from 2 to 65 days). The differences between the two systems are related to calcite dissolution and gypsum precipitation. PMID:24425016

  14. A NAC Gene Regulating Senescence Improves Grain Protein, Zinc, and Iron Content in Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enhancing the nutritional value of food crops is a sensible strategy for improving human nutrition and health. We report here the positional cloning of Gpc-B1, a wheat QTL associated with increased grain protein, Zn and Fe contents. The ancestral wild wheat allele encodes a NAC transcription factor ...

  15. [Contents of zinc, copper and cadmium in mild of women living in Poznań].

    PubMed

    Rydzewska, A; Król, I

    1996-03-01

    A research concerning the contents of Zn, Cu, Cd was carried out in 33 samples of human milk. The woman were inhabitants of Poznań (urban industrial area). The following concentrations of the metals were found: Zn 8.20 +/- 2.76 mg/l (colostrum 9.67, transitional 7.48 mg/l), Cu 0.54 +/- 0.16 mg/l (colostrum 0.47, transitional 0.60 mg/l), Cd 0.62 +/- 0.28 micrograms/l. The obtained results were considered regarding the woman's age, the day of puerperium on which the samples was taken, the number of deliveries and smoking factor. A negative correlation between the concentration of Zn and the day of puerperium was stated (p < 0.05). The contents of Zn and Cu doesn't exceed the accepted quantities in dairy products for babies. The contents of Cd in milk was the source of 1/6 PTWI given by FAO/WHO for adults. However it can present the danger to their health. The results of research point out the necessity for undertaking preventive measures and continuing the research on a larger scale. PMID:8647504

  16. The effect of zinc and phytoestrogen supplementation on the changes in mineral content of the femur of rats with chemically induced mammary carcinogenesis.

    PubMed

    Skrajnowska, Dorota; Korczak, Barbara Bobrowska-; Tokarz, Andrzej; Kazimierczuk, Agata; Klepacz, Marta; Makowska, Justyna; Gadzinski, Blazej

    2015-10-01

    The aim of this study was to assess skeletal effects of zinc or zinc with phytoestrogen (resveratrol or genistein) supplementation in an animal model of rats with DMBA-induced mammary carcinogenesis. The changes in bone parameters such as the length and mass were examined, as well as the changes in concentrations of selected minerals: calcium, magnesium, zinc, iron and phosphorus. Moreover, the investigations focused on finding the differences between the levels of iron and zinc in other tissues: the liver, spleen and serum of the examined rats. Fifty-six female Sprague-Dawley rats, 40 days old, were divided into four groups, regardless of the diets: standard (77mg Zn kg/food), zinc (4.6mg/mL via gavage), zinc (4.6mg/mL) plus resveratrol (0.2mg/kgbw), and zinc (4.6mg/mL) plus genistein (0.2mg/kgbw) for a period from 40 days until 20 weeks of age. The study rats were also treated with 7,12-dimethyl-1,2-benz[a]anthracene (DMBA) to induce mammary carcinogenesis. The applied diet and the advanced mammary cancer did not affect macrometric parameters of the rats' bones, but they strongly affected their mineral content. It was found that mammary cancer, irrespectively of the applied diet, significantly modified the iron level in the femur, liver, spleen and serum of the examined rats. In addition, zinc supplementation significantly lowered the levels of calcium, magnesium and phosphorus in the femur of rats with mammary cancer as compared with respective levels in the control group. So, it was found that additional supplementation with zinc, which is generally considered to be an antioxidant, with the co-existing mammary carcinoma, increased the unfavorable changes as concerns the stability of bone tissue. The appropriate combination of zinc and phytoestrogens (resveratrol or genistein) could help prevent or slow bone loss associated with a range of skeletal disorders in breast cancer. PMID:26302916

  17. An evaluation of zinc bearing palygorskite inclusion on the growth performance, mineral content, meat quality, and antioxidant status of broilers.

    PubMed

    Yang, W L; Chen, Y P; Cheng, Y F; Li, X H; Zhang, R Q; Wen, C; Zhou, Y M

    2016-04-01

    The current study was conducted to investigate the effect of zinc (Zn) bearing palygorskite (ZnPal) inclusion on the growth performance, mineral content, meat quality, and antioxidant status of broilers. A total of 240 one-day-old Arbor Acres broiler chicks were randomly allocated into 5 dietary treatments with 6 replicates of 8 chicks. Broilers in the 5 treatments were fed a basal diet supplemented with 0, 20, 40, 60, and 80 mg/kg Zn diet in the form of ZnPal for 42 d, respectively. Birds exhibited similar average daily gain (ADG), average daily feed intake (ADFI), and feed/gain ratio (F:G) among groups during the 42-day study (P>0.05). ZnPal supplementation linearly increased iron (Fe) (P=0.031) and magnesium (Mg) (P=0.002) content in the pectoralis major muscle. Similarly, the inclusion of ZnPal tended to increase Zn content in the thigh (P=0.072) and linearly increase Zn content in the pectoralis major muscle (P=0.055). The concentration of copper (Cu) in the thigh was linearly decreased by ZnPal inclusion (P=0.011). Meanwhile, a quadratic trend for reduced Cu content was observed in the pectoralis major muscle (P=0.074) and thigh (P=0.082), respectively. The supplementation of ZnPal linearly reduced cooking loss in the pectoralis major muscle (P=0.013), and linearly (P=0.029) and quadratically (P=0.034) decreased cooking loss in the thigh. Malondialdehyde (MDA) concentration in the thigh was linearly (P=0.020) and quadratically (P=0.017) reduced by ZnPal inclusion. Additionally, ZnPal supplementation tended to linearly enhance total antioxidant capacity (T-AOC) activity of the pectoralis major muscle (P=0.083). The results obtained in the current study indicated that ZnPal inclusion could alter muscular mineral accumulation, improve meat quality, and enhance the muscular antioxidant capacity of broilers, and Zn supplementation in the form of ZnPal at the dosage of 20 mg/kg would be sufficient in improving meat quality and muscular oxidative status. PMID

  18. [Research on zinc content in leaf of Olinda Valencia orange using visible near infrared spectroscopy model].

    PubMed

    Yi, Shi-lai; Deng, Lie; He, Shao-lan; Zheng, Yong-qiang; Wang, Liang; Zhao, Xu-yang

    2010-11-01

    Olinda valencia orange leaves dry powder-like were taken as sample, and chemical analysis combined with technology of visible near-infrared spectroscopy (Vis/NIRS) was used, through the treatment process of second derivative spectrum of samples of the original spectrum and denoising (Noise). Meanwhile, method of partial least squares (PLS) and cross-validation were used to establish maths model of Zn concentration which applying band combination composited by 400-500 and 1201-1300 nm of characteristic wavelength band. The coefficient of establishing models is 0.9975, while the coefficient of correlation coefficient of prediction is 0.9920. The root mean square error of prediction (RMSEP) of cross-validation is 0.5868. Therefore, the means using visible near-infrared spectroscopy (Vis/NIRS) and the methods of cross-validation and PLS to establish the spectral correction model reflecting the Zn content in leaves and characteristic wavelength bands can detect the Zn content in citrus leaves quantitatively and quickly. PMID:21284155

  19. Cadmium, Copper, Lead, and Zinc Contents of Fish Marketed in NW Mexico

    PubMed Central

    Frías-Espericueta, Martín G.; Zamora-Sarabia, Francia K. G.; Osuna-López, J. Isidro; Muy-Rangel, María D.; Rubio-Carrasco, Werner; Aguilar-Juárez, Marisela

    2014-01-01

    To assess if they were within the safety limits for human consumption, the Cd, Cu, Pb, and Zn contents of fish muscles, bought from separate stalls of the fish markets of nine cities of NW Mexico, were determined by atomic absorption spectrophotometry. Considering all fish and markets, the mean contents were Zn: 23.23 ± 5.83, Cu: 1.72 ± 0.63, Cd: 0.27 ± 0.07, and Pb: 0.09 ± 0.04 µg/g (dry weight). Cu, Zn, and Pb did not reach levels of concern for human consumption, but the high Cd values determined in Mazatlán (Mugil cephalus: 0.48 ± 0.15; Diapterus spp.: 0.57 ± 0.33; Lutjanus spp.: 0.72 ± 0.12; small shark: 0.87 ± 0.19 µg/g dry weight) indicate that this was the only metal of concern for human health because the daily individual consumption of fish muscle to reach the PTDI would be within 0.27 and 0.41 kg. PMID:24526908

  20. Cadmium, copper, lead, and zinc contents of fish marketed in NW Mexico.

    PubMed

    Frías-Espericueta, Martín G; Zamora-Sarabia, Francia K G; Osuna-López, J Isidro; Muy-Rangel, María D; Rubio-Carrasco, Werner; Aguilar-Juárez, Marisela; Voltolina, Domenico

    2014-01-01

    To assess if they were within the safety limits for human consumption, the Cd, Cu, Pb, and Zn contents of fish muscles, bought from separate stalls of the fish markets of nine cities of NW Mexico, were determined by atomic absorption spectrophotometry. Considering all fish and markets, the mean contents were Zn: 23.23 ± 5.83, Cu: 1.72 ± 0.63, Cd: 0.27 ± 0.07, and Pb: 0.09 ± 0.04 µg/g (dry weight). Cu, Zn, and Pb did not reach levels of concern for human consumption, but the high Cd values determined in Mazatlán (Mugil cephalus: 0.48 ± 0.15; Diapterus spp.: 0.57 ± 0.33; Lutjanus spp.: 0.72 ± 0.12; small shark: 0.87 ± 0.19 µg/g dry weight) indicate that this was the only metal of concern for human health because the daily individual consumption of fish muscle to reach the PTDI would be within 0.27 and 0.41 kg. PMID:24526908

  1. Reported zinc, but not copper, intakes influence whole body bone density, mineral content and T score responses to zinc and copper supplementation in healthy postmenopausal women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A supplementation trial starting with 224 postmenopausal women provided with adequate vitamin D and calcium was conducted to determine whether increased copper and zinc intakes would reduce the risk for bone loss. Healthy women aged 51-80 years were recruited for a double-blind, placebo-controlled s...

  2. The effects of the pressure and the oxygen content of the sputtering gas on the structure and the properties of zinc oxy-nitride thin films deposited by reactive sputtering of zinc

    NASA Astrophysics Data System (ADS)

    Jiang, Nanke; Georgiev, Daniel G.; Jayatissa, Ahalapitiya H.

    2013-02-01

    Zinc nitride and oxy-nitride thin films were prepared by reactive magnetron rf sputtering of zinc in either nitrogen-argon or nitrogen-argon-oxygen ambient. The effects of varying the total sputtering pressure and the oxygen fraction in the total sputtering gas mixture on the microstructure, electrical and optical properties were investigated. With increasing the sputtering pressure, the dominant phase comprising the film material changes from the crystalline zinc nitride phase to crystalline zinc oxide. The characteristic pressure, at which this change in the dominant phase is observed, decreases with the increase of the oxygen fraction in the total sputtering gas mixture. The increase of the oxygen content in the films (from 5 at.% to a maximum of 40 at.%) and the downward shift in the optical absorption edge (from 920 to 400 nm), combined with the x-ray diffraction data, support these observations, indicating the controllable fabrication of an oxy-nitride film material. Correlations between the films’ fabrication conditions, including post-deposition annealing, their structure and composition, and their electrical properties are examined as well.

  3. Effect of organic amendments and mineral fertilizer on zinc bioavailability, plant content and translocation

    NASA Astrophysics Data System (ADS)

    Chami, Ziad Al; Cavoski, Ivana; Mondelli, Donato; Miano, Teodoro

    2013-04-01

    Organic matter plays a key role in heavy metal bioavailability through changes in soil chemical characteristics, and by its metal-chelating ability, the latter being one of the most important factors controlling the mobility and bioavailability of heavy metals in the soil-plant system. In this research, rocket (Eruca vesicaria L. Cavalieri), a common edible plant species in the Mediterranean regions, was used as bio-indicator to evaluate the effect of different organic amendments on Zn toxicity, absorption, and translocation. The main objectives of this study were to investigate the bioavailability of Zn in an artificially contaminated soil after the addition of compost, manure and chemical fertilizers at agronomically recommended doses and to evaluate their ability to reduce Zn concentration in the edible plant part. A greenhouse pots experiment was carried out using rocket plant grown on an artificially contaminated soil. In this study, the effect of compost, manure and chemical fertilizers on Zn fate in a soil-plant system was evaluated. At the end of the experiment main growth parameters and Zn content in plants were determined. In addition, Zn speciation in the soil was assessed using the original BCR sequential extraction and the DTPA extraction. The overall assessment of experimental results is that compost, followed by chemical fertilizers treatments, was the most efficient in enhancing plant growth and decreasing metal toxicity and concentrations in plant tissues. Manure amendments increased plant Zn content and toxicity in rocket plants. In the case of compost treatment, this effect can be attributed to the humified OM present in compost; while the negative effect of manure is due to its content in low molecular weight organic acids. The effect of chemical fertilizers treatment could be attributed to the addition of P fertilizer in soluble and highly available forms to the plants. On the contrary, using DTPA and BCR sequential extraction procedure, all

  4. Spectroscopic and dielectric response of zinc bismuth phosphate glasses as a function of chromium content

    SciTech Connect

    Rao, P. Srinivasa; Babu, P. Ramesh; Vijay, R.; Narendrudu, T.; Veeraiah, N.; Rao, D. Krishna

    2014-09-15

    Graphical abstract: 20ZnF{sub 2}–(20 − x)Bi{sub 2}O{sub 3}–60P{sub 2}O{sub 5}:xCr{sub 2}O{sub 3} (0 ≤ x ≤2 mol%) glasses are prepared by melt quenching technique. The optical absorption spectra of present glasses are analyzed as a function of chromium content. The absorption bands are assigned to {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 1g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 2g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 2}T{sub 1g}(G) and {sup 4}A{sub 2g}(F) ⟶ {sup 2}E{sub g}(G) transitions of Cr{sup 3+} ions. - Highlights: • ZnF{sub 2}–Bi{sub 2}O{sub 3}–P{sub 2}O{sub 5}:Cr{sub 2}O{sub 3} glasses were prepared by melt quenching and annealing. • Spectroscopic and dielectric properties of chromium ions were investigated. • ESR and optical absorption spectra indicate the co-existence of Cr{sup 6+} ions with Cr{sup 5+} ions and Cr{sup 3+} ions. • Cr{sup 3+} ions act as modifiers and influence the semiconducting nature of the glass system. - Abstract: 20ZnF{sub 2}–(20 − x)Bi{sub 2}O{sub 3}–60P{sub 2}O{sub 5}:xCr{sub 2}O{sub 3} (0 ≤ x ≤2 mol%) glasses are prepared by melt quenching technique. Amorphous nature of these samples is confirmed by X-ray diffraction (XRD) analysis. FTIR study reveals bands due to CrO{sub 6}(o{sub d}) and CrO{sub 4}{sup 2−}(T{sub d}) units along with conventional phosphate groups. The optical absorption and ESR studies of present glasses are analyzed as a function of chromium content. The absorption bands are assigned to {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 1g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 4}T{sub 2g}(F), {sup 4}A{sub 2g}(F) ⟶ {sup 2}T{sub 1g}(G) and {sup 4}A{sub 2g}(F) ⟶ {sup 2}E{sub g}(G) transitions of Cr{sup 3+} ions. The highest concentration of Cr{sup 3+} ions (in octahedral sites, with network modifying positions) is found in the sample with 2.0 mol% of Cr{sub 2}O{sub 3}. The analysis of dielectric properties indicates a gradual increase in semiconducting character with increase in the concentration of

  5. [Zinc, copper, iron, calcium, phosphorus and magnesium content of maternal milk during the first 3 weeks of lactation].

    PubMed

    Itriago, A; Carrión, N; Fernández, A; Puig, M; Dini, E

    1997-03-01

    Zinc, Copper, Iron. Calcium Phosphorous and Magnesium contents were determined in early milk samples in 72 mothers from Caracas city. The samples were collected during three different lactation stages: calostro (3 days), transitional (7 days) and mature milk (21 days). The more significant changes in the concentration of the studied elements were observed during the first two weeks, them they stabilize during the third week. The Zn, Cu, Fe, Ca, P and Mg average concentration found in calostro samples were 7.1 +/- 2.5 micrograms/ml; 0.52 +/- 0.15 microgram/ml; 0.49 +/- 0.14 microgram/ml; 214 +/- 62 micrograms/ml, 107 +/- 27 micrograms/ml and 33.3 +/- 7.5 micrograms/ml. respectively. For the transitional milk samples the average concentration found for the studied elements were: 4.0 +/- 1.0 micrograms/ml; 0.50 +/- 0.10 microgram/ml; 0.38 +/- 0.08 microgram/ml, 292 +/- 62 micrograms/ml; 213 +/- 36 micrograms/ml and 30.4 +/- 5.2 micrograms/ml. For the mature milk samples the results were: 2.8 +/- 2.7 micrograms/ml; 0.47 +/- 0.08 microgram/ml; 0.36 +/- 0.09 microgram/ml; 244 +/- 49 micrograms/ml; 175 +/-35 micrograms/ml and 25.2 +/- 3.3 micrograms/ml. The concentration range for all trace elements studied (Cu, Fe and Zn) can be considered normal. For the major elements (Ca, P and Mg) the results obtained in our work are similar to those reported for other countries. These facts allows to conclude that the nutritional state of this mother population is adequate to satisfy the lactate's requirements during their first live stage. PMID:9429635

  6. Effect of sex and dietary organic zinc on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens.

    PubMed

    Salim, H M; Lee, H R; Jo, C; Lee, S K; Lee, Bong Duk

    2012-06-01

    Zinc (Zn) is an essential mineral for animal development and function. A study was carried out to evaluate the effect of sex and dietary organic zinc (OZ) on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens. A total of 240 1-day-old male and 240 female broiler chicks (Cobb × Cobb) were assigned to two dietary levels of OZ (2 × 2 factorial) with six replicates per treatment (20 birds/replicate pen). The OZ supplementation levels were 0 and 25 ppm. Results showed that OZ supplementation did not affect the growth performance of male and female broilers, but the males showed significantly better (P < 0.05) growth performance than females did. Similarly, OZ supplementation did not affect the thickness of both the back and thigh skin of male and female broilers; however, males had thicker skin than females. Dietary OZ supplementation did not affect collagen contents in the skin and meat samples. Male broilers had higher skin collagen contents than females, but no sex difference was found in meat collagen contents. OZ supplementation did not affect the shear force values of skin and meat samples. Male broilers had higher shear force values of back skin than females, but not in the meat samples. Dietary OZ supplementation increased (P < 0.05) the thigh meat Zn content in both sexes. The plasma Ca content was significantly (P < 0.05) increased by dietary OZ supplementation; however, other blood parameters were not affected by dietary OZ supplementation. Males had higher plasma glucose and cholesterol content than females. It is concluded that dietary OZ supplementation at the level of 25 ppm does not affect the growth performance and skin quality of broiler chickens but increases the Zn content in thigh meat and Ca content in plasma of broiler chickens. Male broilers had better growth performance and skin quality than females. PMID:22167309

  7. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae)

    NASA Astrophysics Data System (ADS)

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-04-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation.

  8. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae).

    PubMed

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-12-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation. PMID:27107771

  9. Effect of exercise and protein intake during pregnancy on maternal and fetal zinc content in the Sprague-Dawley rat

    SciTech Connect

    Asente, R.A.; Cameron, S.R.; Taper, L.J.

    1986-03-05

    Pregnant Sprague-Dawley rats (179) were divided into four groups: sedentary-standard protein diet, sedentary-high protein diet, exercising-standard protein diet and exercising-high protein diet. The standard protein diet contained 24.77% protein; all other nutrients were supplied in amounts required for normal parturition. After aclimitization, the exercising dams, regardless of diet, were forced to swim continuously for one and one-half hours/day until sacrifice. The four major groups were further subdivided into 28 groups, designated by three-day intervals according to gestational day - days 3, 6, 9, 12, 15, 18 and 21. Uterine tissues were analyzed for zinc; fetal and placental tissues were separated from uterine tissue for days 15 through 21 only. Uterine zinc was affected solely by gestation; absolute placental zinc values were lowest in the sedentary-high and exercising-low protein groups, while the exercising-high protein group possessed the greatest. No significant difference was detected in fetal zinc concentrations. Fetal tissues from exercising dams weighed significantly less than fetal tissue from the sedentary dams; and sedentary-high protein dams produced significantly more fetuses than the exercising-high protein dams. Both protein intake and exercise significantly affect normal parturition and zinc metabolism in the rat.

  10. Endogenous ochronosis.

    PubMed

    Turgay, E; Canat, D; Gurel, M S; Yuksel, T; Baran, M F; Demirkesen, C

    2009-12-01

    Endogenous ochronosis or alkaptonuria is a rare, autosomal recessive disease of tyrosine metabolism that is caused by a deficiency of the enzyme homogentisic acid oxidase. The disease results in the accumulation and deposition of homogentisic acid in the cartilage, eyelids, forehead, cheeks, axillae, genital region, buccal mucosa, larynx, tympanic membranes, and tendons. The disease generally presents in adults with arthritis and skin abnormalities; occasionally, involvement of other organs may be seen. A 49-year-old man was referred to our clinic with verrucous lesions on his hands. On physical examination, caviar-like ochronotic papules were found around his eyes and the helix cartilage of his ears, and on the dorsa of both hands. There were brown macules on the sclera (Osler's sign). The patient had arthritis and nephrolithiasis, and a sample of his urine darkened upon standing. Histopathological examination showed deposition of ochronotic pigment. High-dose ascorbic acid was given, and the patient showed improvement on follow-up examination 6 months later. PMID:20055850

  11. Moderate consumption of wine, through both its phenolic compounds and alcohol content, promotes hydroxytyrosol endogenous generation in humans. A randomized controlled trial.

    PubMed

    Pérez-Mañá, Clara; Farré, Magí; Rodríguez-Morató, Jose; Papaseit, Esther; Pujadas, Mitona; Fitó, Montserrat; Robledo, Patricia; Covas, Maria-Isabel; Cheynier, Véronique; Meudec, Emmanuelle; Escudier, Jean-Louis; de la Torre, Rafael

    2015-06-01

    In humans, urinary hydroxytyrosol (OHTyr) concentrations have been associated to alcohol and wine consumption. To explore the role of wine components on promoting an endogenous OHTyr generation we performed a cross-over, double-blind, randomized controlled clinical trial (n = 28 healthy volunteers). Ethanol (wine and vodka), dealcoholized wine, and placebo were administered. Alcohol, dealcoholized wine, and particularly wine promoted a de novo OHTyr generation in vivo in humans. Potential OHTyr precursors (tyrosine, tyrosol, tyramine) were investigated in rats. Tyrosol was metabolized to OHTyr. Collating both studies, it is postulated that an increased Tyr bioavailability, a shift to a reductive pathway in dopamine and tyramine oxidative metabolism, and the biotransformation of Tyr to OHTyr were mechanisms involved in the OHTyr endogenous generation. PMID:25712532

  12. Zinc metallothionein imported into liver mitochondria modulates respiration

    PubMed Central

    Ye, Bin; Maret, Wolfgang; Vallee, Bert L.

    2001-01-01

    Metallothionein (MT) localizes in the intermembrane space of liver mitochondria as well as in the cytosol and nucleus. Incubation of intact liver mitochondria with physiological, micromolar concentrations of MT leads to the import of MT into the mitochondria where it inhibits respiration. This activity is caused by the N-terminal β-domain of MT; in this system, the isolated C-terminal α-domain is inactive. Free zinc inhibits respiration at concentrations commensurate with the zinc content of either MT or the isolated β-domain, indicating that MT inhibition involves zinc delivery to mitochondria. Respiratory inhibition of uncoupled mitochondria identifies the electron transfer chain as the primary site of inhibition. The apoform of MT, thionein, is an endogenous chelating agent and activates zinc-inhibited respiration with a 1:1 stoichiometry ([zinc binding sites]/[zinc]). Carbamoylation of the lysines of MT significantly attenuates the inhibitory effect, suggesting that these residues are critical for the passage of MT through the outer mitochondrial membrane. Such an import pathway has been proposed for other proteins that also lack a mitochondrial targeting sequence, e.g., apocytochrome c, and possibly Cox17, a mitochondrial copper chaperone that is the only protein known so far to exhibit significant primary sequence homology to MT. The presence and respiratory inhibition of MT in liver, but not heart, mitochondria suggest a hitherto unknown biological modulating activity of MT in cellular respiration and energy metabolism in a tissue-specific manner. PMID:11226237

  13. Zinc Modulation of Glycine Receptors

    PubMed Central

    Trombley, Paul Q.; Blakemore, Laura J.; Hill, Brook J.

    2011-01-01

    Glycine receptors are widely expressed in the mammalian central nervous system, and previous studies have demonstrated that glycine receptors are modulated by endogenous zinc. Zinc is concentrated in synaptic vesicles in several brain regions but is particularly abundant in the hippocampus and olfactory bulb. In the present study, we used patch-clamp electrophysiology of rat hippocampal and olfactory bulb neurons in primary culture to examine the effects of zinc on glycine receptors. Although glycine has been reported to reach millimolar concentrations during synaptic transmission, most previous studies on the effects of zinc on glycine receptors have used relatively low concentrations of glycine. High concentrations of glycine cause receptor desensitization. Our current results extend our previous demonstration that the modulatory actions of zinc are largely prevented when co-applied with desensitizing concentrations of glycine (300 μM), suggesting that the effects of zinc are dependent on the state of the receptor. In contrast, pre-application of 300 μM zinc, prior to glycine (300 μM) application, causes a slowly developing inhibition with a slow rate of recovery, suggesting that the timing of zinc and glycine release also influences the effects of zinc. Furthermore, previous evidence suggests that synaptically released zinc can gain intracellular access, and we provide the first demonstration that low concentrations of intracellular zinc can potentiate glycine receptors. These results support the notion that zinc has complex effects on glycine receptors and multiple factors may interact to influence the efficacy of glycinergic transmission. PMID:21530619

  14. [INVESTIGATION OF IRON, ZINC, STABLE STRONTIUM AND LITHIUM CONTENT IN BIOLOGICAL FLUIDS AND TISSUES DURING EXPERIMENTAL SPACE FLIGHT SIMULATION].

    PubMed

    Protasova, O V; Maksimova, I A; Morukov, B V; Protasov, S V; Ushakov, I B

    2015-01-01

    In an experiment with space flight simulation, atomic emission spectral analysis with inductively coupled argon plasma was employed to measure iron, zinc, stable strontium and lithium in blood serum and its ultrafiltered fraction, and excretion with daily urine and hair. Monitoring of serum iron and its ultraviolet fraction showed good balance of these parameters in all periods of the experiment. Blood serum was found to contain exclusively iron bound with protein carriers. In the experiment, serum zinc was distinctively dependent on the nutrient status. Stable strontium excretion with daily urine can be a biological indicator of its homeostasis. The experiment factors had no effect on the lithium form in serum, i.e. lithium was invariably present in the ionized form and in quantities equal to ultrafiltered lithium in all blood samples in all periods of the experiment. PMID:26292427

  15. Copper and zinc affect the activity of plasma membrane H+-ATPase and thiol content in aquatic fungi.

    PubMed

    Azevedo, M M; Guimarães-Soares, L; Pascoal, C; Cássio, F

    2016-05-01

    Aquatic hyphomycetes are the major microbial decomposers of plant litter in streams. We selected three aquatic hyphomycete species with different abilities to tolerate, adsorb and accumulate copper and zinc, and we investigated the effects of these metals on H+-ATPase activity as well as on the levels of thiol (SH)-containing compounds. Before metal exposure, the species isolated from a metal-polluted stream (Heliscus submersus and Flagellospora curta) had higher levels of thiol compounds than the species isolated from a clean stream (Varicosporium elodeae). However, V. elodeae rapidly increased the levels of thiols after metal exposure, emphasizing the importance of these compounds in fungal survival under metal stress. The highest amounts of metals adsorbed to fungal mycelia were found in the most tolerant species to each metal, i.e. in H. submersus exposed to copper and in V. elodeae exposed to zinc. Short-term (10 min) exposure to copper completely inhibited the activity of H+-ATPase of H. submersus and V. elodeae, whilst zinc only led to a similar effect on H. submersus. However, at longer exposure times (8 days) the most metal-tolerant species exhibited increased H+-ATPase activities, suggesting that the plasma membrane proton pump may be involved in the acclimation of aquatic hyphomycetes to metals. PMID:26916755

  16. Total antioxidant capacity, total phenolic content and iron and zinc dialyzability in selected Greek varieties of table olives, tomatoes and legumes from conventional and organic farming.

    PubMed

    Drakou, Marina; Birmpa, Angeliki; Koutelidakis, Antonios E; Komaitis, Michael; Panagou, Efstathios Z; Kapsokefalou, Maria

    2015-03-01

    The objective was to compare 10 types of table olives, 11 types of tomatoes and tomato products and 18 types of legumes from conventional or organic farming for selected nutritional properties. All products were tested for their total antioxidant capacity (TAC) (Ferric Reducing Antioxidant Power (FRAP) assay) and total phenolic content (Folin-Ciocalteau method). Tomatoes and legumes were further tested for iron and zinc dialyzability after in vitro digestion. Ascorbic acid content of tomatoes was also measured. The study resulted that the nutritional properties of olives, tomatoes and legumes tested were different among the various cultivars but, in most cases, not between products from organic or conventional farming. Natural black olives, cherry and santorini tomatoes and lentils exhibited superior nutritional properties. PMID:25582178

  17. Zinc Enzymes.

    ERIC Educational Resources Information Center

    Bertini, I.; And Others

    1985-01-01

    Discusses the role of zinc in various enzymes concerned with hydration, hydrolysis, and redox reactions. The binding of zinc to protein residues, properties of noncatalytic zinc(II) and catalytic zinc, and the reactions catalyzed by zinc are among the topics considered. (JN)

  18. Zinc tolerance and zinc removal ability of living and dried biomass of Desmodesmus communis.

    PubMed

    Novák, Zoltán; Jánószky, Mihály; B-Béres, Viktória; Nagy, Sándor Alex; Bácsi, István

    2014-12-01

    Effects of zinc on growth, cell morphology, oxidative stress, and zinc removal ability of the common phytoplankton species Desmodesmus communis were investigated at a concentration range of 0.25-160 mg L(-1) zinc. Cell densities and chlorophyll content decreased in treated cultures, changes in coenobia morphology and elevated lipid peroxidation levels appeared above 2.5 mg L(-1) zinc. The most effective zinc removal was observed at 5 mg L(-1) zinc concentration, while maximal amount of removed zinc appeared in 15 mg L(-1) zinc treated culture. Removed zinc is mainly bound on the cell surface. Dead biomass adsorbed more zinc than living biomass relative to unit of dry mass, but living biomass was more effective, relative to initial zinc content. This study comprehensively examines the zinc tolerance and removal ability of D. communis and demonstrates, in comparison with published literature, that these characteristics of different isolates of the same species can vary within a wide range. PMID:25193446

  19. Zinc poisoning

    MedlinePlus

    ... other materials to make industrial items such as paint, dyes, and more. These combination substances can be ... Compounds used to make paint, rubber, dyes, wood preservatives, and ... Zinc chloride Zinc oxide (relatively nonharmful) Zinc ...

  20. [Effect of zinc deficiency on 3',5'-cyclic-AMP content and parameters of energy metabolism in the rat].

    PubMed

    Roth, H P; Kirchgessner, M

    1983-06-01

    Loss of appetite, strongly reduced feed intake, and stop in weight gain are characteristic signs of alimentary zinc deficiency. The present paper investigates some parameters of the energy metabolism of Zn-deficient rats in order to obtain information on possible disturbances. The blood of Zn-deficient rats showed an increased activity of adenosine triphosphatase (ATPase) in comparison to ad-libitum- and pair-fed control animals. Therefore the concentration of adenosine triphosphate (ATP) was reduced and the concentration of adenosine diphosphate (ADP) increased in deficient animals. As a consequence, the ratio ATP/ADP was strongly reduced in Zn-deficient rats compared with both control groups. The concentration of adenosine monophosphate (AMP) was reduced in the blood of Zn-deficient rats. The levels of c-AMP in serum and urine were markedly increased in Zn-deficient rats in comparison with both control groups. Key enzymes of energetic utilization of carbohydrates such as fructose-1.6-biphosphatase and glucose-6-phosphate dehydrogenase were reduced in their activities in livers and kidneys of Zn-deficient animals. The results show that alimentary Zn deficiency impairs some parameters of the energy metabolism. The problems of reduced feed intake in Zn deficiency still remain unsolved. PMID:6308919

  1. Evaluation of the content and bioaccessibility of iron, zinc, calcium and magnesium from groats, rice, leguminous grains and nuts.

    PubMed

    Suliburska, Joanna; Krejpcio, Zbigniew

    2014-03-01

    The objective of this study was to determine the content and the bioaccessibility of minerals (Fe, Zn, Ca and Mg) in commonly consumed food products, such as cereal groats, rice, leguminous grains and nuts purchased from the local market. The contents of Fe, Zn, Ca and Mg in foods were assayed after dry ashing of samples, while the bioaccessibility of these minerals after enzymatic in vitro digestion, was determined by flame atomic absorption spectrometry. A relatively high content of Fe was found in cashew nuts and green lentils, while cashew nuts and buckwheat groats had the highest concentration of Zn. It was found that the highest amount of macro-elements was generally in nuts, in particular: brazil nuts (Ca and Mg), cashews (Mg) and hazelnuts (Ca and Mg). Concerning the mineral bioaccessibility, the highest values for Fe were obtained in cashew nuts and green lentils (2.8 and 1.7 mg/100 g), for Zn in green lentils (2.1 mg/100 g), for Ca in brazil nuts and shelled pea (32.6 and 29.1 mg/100 g), while for Mg in shelled peas and green lentils (43.4 and 33.9 mg/100 g). Generally, the best sources of bioaccessible minerals seem to be leguminous grains and nuts. PMID:24587537

  2. Influence of different histidine sources and zinc supplementation of broiler diets on dipeptide content and antioxidant status of blood and meat.

    PubMed

    Kopeć, W; Jamroz, D; Wiliczkiewicz, A; Biazik, E; Pudlo, A; Hikawczuk, T; Skiba, T; Korzeniowska, M

    2013-01-01

    1. The objective of this study was to investigate how a diet containing spray-dried blood cells (SDBC) (4%) with or without zinc (Zn) would affect the concentration of two histidine heterodipeptides and the antioxidant status of broiler blood and breast muscles. 2. The study was carried out on 920 male Flex chickens randomly assigned to 4 dietary treatments: I - control, II - diet I with SDBC, III - diet I with SDBC and supplemented with Zn and IV - diet I supplemented with L-histidine. Birds were raised on floor littered with wood shavings, given free access to water and fed ad libitum. Performance indices were measured on d 1, 21 and 42. 3. The activity of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase was analysed in plasma, erythrocytes and muscle tissue. The total antioxidant capacity of plasma and breast muscles was measured by 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, as well as by ferric reducing antioxidant power (FRAP). Carnosine/anserine content of meat and plasma were determined using HPLC. Diets and breast muscles were analysed for amino acid profile and selected microelement content. 4. Histidine supplementation of the diet increased glutathione peroxidase activity in plasma and superoxide dismutase activity in erythrocytes. Moreover, the addition of SDBC or pure histidine in the diet increased histidine dipeptide content and activated enzymatic and non-enzymatic antioxidant systems in chicken blood and muscles. However, it led to lower growth performance indices. 5. The enrichment of broiler diets with Zn increased the antioxidant potential and the activity of superoxide dismutase in plasma, which was independent of the histidine dipeptide concentration. Zn supplementation combined with SDBC in a broiler diet led to the increase of superoxide dismutase and glutathione peroxidase activity, but it did not affect the radical

  3. Effect of Li 2O content on physical and structural properties of vanadyl doped alkali zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Raghavendra Rao, T.; Rama Krishna, Ch.; Udayachandran Thampy, U. S.; Venkata Reddy, Ch.; Reddy, Y. P.; Sambasiva Rao, P.; Ravikumar, R. V. S. S. N.

    2011-05-01

    The effect of Li 2O content in vanadyl doped 20ZnO+ xLi 2O+(30- x)Na 2O+50B 2O 3 (5≤ x≥25) glasses has been studied with respect to their physical and structural properties. The absence of sharp peaks in XRD spectra of these glass samples confirms the amorphous nature. The physical parameters like density, refractive index, ionic concentration and electronic polarizability vary non-linearly with x mol% depending on the diffusivities of alkali ions. EPR and optical absorption spectra reveal that the resonance signals are characteristics of VO 2+ ions in tetragonally compressed octahedral site. Spin-Hamiltonian, crystal field, tetragonal field and bonding parameters are found to be in good agreement with the other reported glass systems. The tetragonal distortion ( g⊥- g∥) and Dt reveals that their values vary non-linearly with Li 2O content and reaches a minimum at x=10 mol%. An anomaly of character has been observed in all the properties of vanadyl doped glass systems, which gives a clear indication of mixed alkali effect.

  4. Assessment of genetic diversity in rice [Oryza sativa L.] germplasm based on agro-morphology traits and zinc-iron content for crop improvement.

    PubMed

    Roy, Subhas Chandra; Sharma, B D

    2014-04-01

    Genetic resources of landraces (84 cultivars) were collected from various agro-ecological regions of West Bengal and adjoining areas and characterized based on qualitative and quantitative agro-morphological descriptors along with zinc (Zn) and iron (Fe) content. The DUS protocol was employed to study 16 agro-morphological passport data such as: vegetative data (anthocyanin pigmentation, plant habit), reproductive data (flag leaf attitude, stigma colour, panicle attitude), including eight grain quality traits: grain length, grain width, 1000 grains weight, kernel length, kernel breadth etc. Highest seed weight was found in cultivar Khechri (32.04 g/1000 seeds), collected from Sundarban and least seed weight was 9.6 g/1000seeds in Katharibhog. Maturity duration was found very short (<100 days) in Jumla Marshi (97 days) collected from world's coldest rice growing area, Jumla, Nepal. Penultimate leaves breadth was observed broad (>2 cm) in one cultivar Jungli (2.3 cm). Seeds per panicle were 180 in Chinisakkar (medium range), 177 in Dudheswar, and 151 in Ladua. Flag leaf was found in erect condition in late observation in Dudheswar, Enda and Ghiosh. Seventeen cultivars were grouped in the aromatic rice category out of total 84 local landraces. Twenty-one cultivars were with awn, whose length ranges from 1.6 mm (Anandi) to 22.5 mm (Tulaipanji). Kernel colour varies from red, yellowish, brownish, creamy white to white. Kernel length varies from 4 mm to 8 mm and breadth 1.90 mm to 3 mm. Kernel length/breadth ration varied from 1.6 to 3.9. Highest ratio of L/B was found in Pusa Basmati 1(3.9) and lowest in Dudhey (1.6). Elongation ration was highest in Kalokure (2.07) and lowest in Phoolpakri (0.62). Nutritional values of mineral contents of iron (Fe) and zinc (Zn) were estimated in all cultivars by Atomic Absorption Spectrophotometic method. Iron concentration varies from 0.25 μg/g to 34.8 μg/g and zinc from 0.85 μg/g to 195.3 μg/g in the landraces

  5. Heavy metal (Pb, Zn, Cd, Fe, and Cu) contents of plant foliage near the Anvil Range lead/zinc mine, Faro, Yukon Territory.

    PubMed

    Pugh, Rachel E; Dick, David G; Fredeen, Arthur L

    2002-07-01

    Mining and processing of lead (Pb)/zinc (Zn) ore at the Anvil Range mine occurred near the town of Faro in the Yukon Territory, Canada, for approximately 30 years, beginning in 1968. A study was undertaken to examine whether the mining activities had left a detectable "footprint" on the environment in the way of heavy metal phytoaccumulation. Foliage of three native plant species was sampled: bog blueberry (Vaccinium uliginosum), Labrador tea (Ledum groenlandicum), and willow (Salix sp.), at approximately 0.25, 2.5, 12, 30, and 200 (control) km distant from the mill (ore-processing facility at the mine). Foliage samples were oven-dried, wet- or dry-ashed, and analyzed for metal content using ICP-AES. In addition to Pb and Zn, the primary ore constituents, copper (Cu), iron (Fe), and cadmium (Cd), were also assayed. As expected, foliar Pb and Zn concentrations were elevated in plants at the sites closest to the mill, i.e., 0.25 and 2.5 km from the mine facility. Copper and Fe, both essential nutrients for plants, were also elevated in foliage at the sites closest to the mill, but not to a level that would be of concern. Foliar Cd levels were highest in Salix relative to the other species but were not affected by proximity to the mill. Results suggest that Ledum may be the best indicator of high environmental concentrations of Pb, while Salix may be the best indicator of elevated Zn and Cd. PMID:12297090

  6. Zinc oxide nanorod assisted rapid single-step process for the conversion of electrospun poly(acrylonitrile) nanofibers to carbon nanofibers with a high graphitic content

    NASA Astrophysics Data System (ADS)

    Nain, Ratyakshi; Singh, Dhirendra; Jassal, Manjeet; Agrawal, Ashwini K.

    2016-02-01

    The effect of incorporation of rigid zinc oxide (ZnO) nanostructures on carbonization behavior of electrospun special acrylic fiber grade poly(acrylonitrile) (PAN-SAF) nanofibers was investigated. ZnO nanorods with high aspect ratios were incorporated into a PAN-N,N-dimethylformamide system and the composite nanofibers reinforced with aligned ZnO rods up to 50 wt% were successfully electrospun, and subsequently, carbonized. The morphology and the structural analysis of the resultant carbon nanofibers revealed that the rigid ZnO nanorods, present inside the nanofibers, possibly acted as scaffolds (temporary support structures) for immobilization of polymer chains and assisted in uniform heat distribution. This facilitated rapid and efficient conversion of the polymer structure to the ladder, and subsequently, the graphitized structure. At the end of the process, the ZnO nanorods were found to completely separate from the carbonized fibers yielding pure carbon nanofibers with a high graphitic content and surface area. The approach could be used to eliminate the slow, energy intensive stabilization step and achieve fast conversion of randomly laid carbon nanofiber webs in a single step to carbon nanofibers without the application of external tension or internal templates usually employed to achieve a high graphitic content in such systems.The effect of incorporation of rigid zinc oxide (ZnO) nanostructures on carbonization behavior of electrospun special acrylic fiber grade poly(acrylonitrile) (PAN-SAF) nanofibers was investigated. ZnO nanorods with high aspect ratios were incorporated into a PAN-N,N-dimethylformamide system and the composite nanofibers reinforced with aligned ZnO rods up to 50 wt% were successfully electrospun, and subsequently, carbonized. The morphology and the structural analysis of the resultant carbon nanofibers revealed that the rigid ZnO nanorods, present inside the nanofibers, possibly acted as scaffolds (temporary support structures) for

  7. 46 CFR 148.330 - Zinc ashes; zinc dross; zinc residues; zinc skimmings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Zinc ashes; zinc dross; zinc residues; zinc skimmings... Materials § 148.330 Zinc ashes; zinc dross; zinc residues; zinc skimmings. (a) The shipper must inform the cognizant Coast Guard Captain of the Port in advance of any cargo transfer operations involving zinc...

  8. 46 CFR 148.330 - Zinc ashes; zinc dross; zinc residues; zinc skimmings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Zinc ashes; zinc dross; zinc residues; zinc skimmings... Materials § 148.330 Zinc ashes; zinc dross; zinc residues; zinc skimmings. (a) The shipper must inform the cognizant Coast Guard Captain of the Port in advance of any cargo transfer operations involving zinc...

  9. 46 CFR 148.330 - Zinc ashes; zinc dross; zinc residues; zinc skimmings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Zinc ashes; zinc dross; zinc residues; zinc skimmings... Materials § 148.330 Zinc ashes; zinc dross; zinc residues; zinc skimmings. (a) The shipper must inform the cognizant Coast Guard Captain of the Port in advance of any cargo transfer operations involving zinc...

  10. [Improvement in zinc nutrition due to zinc transporter-targeting strategy].

    PubMed

    Kambe, Taiho

    2016-07-01

    Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health. PMID:27455817

  11. Does elevating silver content in zinc-based glass polyalkenoate cements increase their antibacterial efficacy against two common bacteria using the agar gel diffusion method?

    PubMed

    Coughlan, A; Breed, S M; Ashraf, C; Cardinale, J A; Hall, M M; Towler, M R

    2013-03-01

    The authors have previously shown that it is possible to incorporate silver into a soda-zinc-silicate glass and subsequently form a glass polyalkenoate cement from it. The objective of the research described herein is to determine if incremental increases in the silver content of these glass polyalkenoate cements will increase their antibacterial efficacy against gram-positive and gram-negative bacteria using the accepted spread plate method. Four glass polyalkenoate cements were formulated; three contained increasing amounts of silver incorporated into them (cements A, B, and C, containing 0.33 mol%, 0.66 mol%, and 0.99 mol% silver, respectively) and a fourth contained no silver, which acted as a control (control cement). The handling properties of the glass polyalkenoate cements were evaluated, where working times were around 2 min and setting times ranged from 1 h 17 min to 2 h 41 min. Inductively coupled plasma atomic emission spectroscopy was employed to determine silver ion release with cement maturation for up to 14 days. The majority of silver ions were released within the first 24 h, with up to 2 mg/L cumulative ion release recorded up to 14 days. The antibacterial properties of the coatings were evaluated against Staphylococcus aureus and Pseudomonas aeruginosa bacteria. The silver-glass polyalkenoate cements exhibited antibacterial effect against both bacterial strains. The maximum inhibition zones recorded against S. aureus was 14.8 mm (SD ± 1.11) and against P. aeruginosa was 20.6 mm (SD ± 0.81). Cement B had a greater antibacterial effect compared to cement A, however, cements B and C had comparable antibacterial effects after 14 days even though cement C contained 0.33 mol% more silver than B. This indicates that by increasing the silver content in these cements, the antibacterial efficacy increases to a point, but there is a threshold where further silver ion release does not increase the antibacterial effect

  12. Endogenous Pyrogen Physiology.

    ERIC Educational Resources Information Center

    Beisel, William R.

    1980-01-01

    Discusses the physiology of endogenous pyrogen (EP), the fever-producing factor of cellular origin. Included are: its hormone-like role, its molecular nature, bioassay procedures, cellular production and mechanisms of EP action. (SA)

  13. Bacillus cereus endogenous panophthalmitis.

    PubMed

    Bouza, E; Grant, S; Jordan, C; Yook, R H; Sulit, H L

    1979-03-01

    A case of severe suppurative endogenous panophthalmitis caused by Bacillus cereus resulted from intravenously administered medications. This is the first, to our knowledge, well-documented case of endogenous endophthalmitis associated with this organism. It is recommended that if on Gram's stain of the anterior chamber fluid, Gram-positive rods are seen, chloramphenicol should be administered in addition to penicillin because of the possibility of B cereus infection. PMID:105693

  14. Doped zinc oxide microspheres

    DOEpatents

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  15. Doped zinc oxide microspheres

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-12-14

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel. 4 figures.

  16. The Endogenous Exposome

    PubMed Central

    Nakamura, Jun; Mutlu, Esra; Sharma, Vyom; Collins, Leonard; Bodnar, Wanda; Yu, Rui; Lai, Yongquan; Moeller, Benjamin; Lu, Kun; Swenberg, James

    2014-01-01

    The concept of the Exposome, is a compilation of diseases and one’s lifetime exposure to chemicals, whether the exposure comes from environmental, dietary, or occupational exposures; or endogenous chemicals that are formed from normal metabolism, inflammation, oxidative stress, lipid peroxidation, infections, and other natural metabolic processes such as alteration of the gut microbiome. In this review, we have focused on the Endogenous Exposome, the DNA damage that arises from the production of endogenous electrophilic molecules in our cells. It provides quantitative data on endogenous DNA damage and its relationship to mutagenesis, with emphasis on when exogenous chemical exposures that produce identical DNA adducts to those arising from normal metabolism cause significant increases in total identical DNA adducts. We have utilized stable isotope labeled chemical exposures of animals and cells, so that accurate relationships between endogenous and exogenous exposures can be determined. Advances in mass spectrometry have vastly increased both the sensitivity and accuracy of such studies. Furthermore, we have clear evidence of which sources of exposure drive low dose biology that results in mutations and disease. These data provide much needed information to impact quantitative risk assessments, in the hope of moving towards the use of science, rather than default assumptions. PMID:24767943

  17. Resistant starch does not affect zinc homeostasis in rural Malawian children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study tested the hypothesis that Malawian children at risk for zinc deficiency will have reduced endogenous fecal zinc (EFZ) and increased net absorbed zinc (NAZ) following the addition of high amylose maize resistant starch (RS) to their diet. This was a small controlled clinical trial to dete...

  18. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide.

    PubMed

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnic, Marica; Hurrell, Richard F

    2014-02-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with (67)Zn and (70)Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6-71.0) and was not different from that from zinc gluconate with 60.9% (50.6-71.7). Absorption from zinc oxide at 49.9% (40.9-57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

  19. Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide123

    PubMed Central

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F.

    2014-01-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

  20. Endogenous opioids and reward.

    PubMed

    Van Ree, J M; Niesink, R J; Van Wolfswinkel, L; Ramsey, N F; Kornet, M M; Van Furth, W R; Vanderschuren, L J; Gerrits, M A; Van den Berg, C L

    2000-09-29

    The discovery of endogenous opioids has markedly influenced the research on the biology of addiction and reward brain processes. Evidence has been presented that these brain substances modulate brain stimulation reward, self-administration of different drugs of abuse, sexual behaviour and social behaviour. There appears to be two different domains in which endogenous opioids, present in separate and distinct brain regions, are involved. One is related to the modulation of incentive motivational processes and the other to the performance of certain behaviours. It is concluded that endogenous opioids may play a role in the vulnerability to certain diseases, such as addiction and autism, but also when the disease is present, such as alcoholism. PMID:11033317

  1. History of Zinc in Agriculture12

    PubMed Central

    Nielsen, Forrest H.

    2012-01-01

    Zinc was established as essential for green plants in 1926 and for mammals in 1934. However, >20 y would pass before the first descriptions of zinc deficiencies in farm animals appeared. In 1955, it was reported that zinc supplementation would cure parakeratosis in swine. In 1958, it was reported that zinc deficiency induced poor growth, leg abnormalities, poor feathering, and parakeratosis in chicks. In the 1960s, zinc supplementation was found to alleviate parakeratosis in grazing cattle and sheep. Within 35 y, it was established that nearly one half of the soils in the world may be zinc deficient, causing decreased plant zinc content and production that can be prevented by zinc fertilization. In many of these areas, zinc deficiency is prevented in grazing livestock by zinc fertilization of pastures or by providing salt licks. For livestock under more defined conditions, such as poultry, swine, and dairy and finishing cattle, feeds are easily supplemented with zinc salts to prevent deficiency. Today, the causes and consequences of zinc deficiency and methods and effects of overcoming the deficiency are well established for agriculture. The history of zinc in agriculture is an outstanding demonstration of the translation of research into practical application. PMID:23153732

  2. The requirement of zinc and calcium ions for functional MMP activity in demineralized dentin matrices

    PubMed Central

    Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Hoshika, Tomohiro; Carrilho, Marcela; Breschi, Lorenzo; Tjäderhane, Leo; Nishitani, Yoshihiro; Carvalho, Ricardo M.; Looney, Stephen; Tay, Franklin R.; Pashley, David H.

    2010-01-01

    The progressive degradation of resin-dentin bonds is due, in part, to the slow degradation of collagen fibrils in the hybrid layer by endogenous matrix metalloproteinases (MMPs) of the dentin matrix. In in vitro durability studies, the storage medium composition might be important because the optimum activity of MMPs requires both zinc and calcium. Objective This study evaluated the effect of different storage media on changes in matrix stiffness, loss of dry weight or solubilization of collagen from demineralized dentin beams incubated in vitro for up to 60 days. Methods Dentin beams (1×2×6mm) were completely demineralized in 10% phosphoric acid. After baseline measurements of dry mass and elastic modulus (E) (3-point bending, 15% strain) the beams were divided into 5 groups (n=11/group) and incubated at 37°C in either media containing both zinc and calcium designated as complete medium(CM), calcium-free medium, zinc-free medium, a doubled-zinc medium or water. Beams were retested at 3, 7, 14, 30, and 60 days of incubation. The incubation media was hydrolyzed with HCl for the quantitation of hydroxyproline (HOP) as an index of solubilization of collagen by MMPs. Data were analyzed using repeated measures of ANOVA. Results Both the storage medium and storage time showed significant effects on E, mass loss and HOP release (p<0.05). The incubation in CM resulted in relatively rapid and significant (p<0.05) decreases in stiffness, and increasing amounts of mass loss. The HOP content of the experimental media also increased with incubation time but was significantly lower (p<0.05) than in the control CM medium, the recommended storage medium. Conclusions The storage solutions used to age resin-dentin bonds should be buffered solutions that contain both calcium and zinc. The common use of water as an aging medium may underestimate the hydrolytic activity of endogenous dentin MMPs. PMID:20688380

  3. Endogenous Retroviruses and Human Evolution

    PubMed Central

    Lebedev, Yuri; Sverdlov, Eugene

    2002-01-01

    Humans share about 99% of their genomic DNA with chimpanzees and bonobos; thus, the differences between these species are unlikely to be in gene content but could be caused by inherited changes in regulatory systems. Endogenous retroviruses (ERVs) comprise ∼ 5% of the human genome. The LTRs of ERVs contain many regulatory sequences, such as promoters, enhancers, polyadenylation signals and factor-binding sites. Thus, they can influence the expression of nearby human genes. All known human-specific LTRs belong to the HERV-K (human ERV) family, the most active family in the human genome. It is likely that some of these ERVs could have integrated into regulatory regions of the human genome, and therefore could have had an impact on the expression of adjacent genes, which have consequently contributed to human evolution. This review discusses possible functional consequences of ERV integration in active coding regions. PMID:18629260

  4. Reconstruction of paleo-particulate organic carbon fluxes for the Campbell Plateau region of southern New Zealand using the zinc content of sponge spicules

    NASA Astrophysics Data System (ADS)

    Ellwood, Michael J.; Kelly, Michelle; Neil, Helen; Nodder, Scott D.

    2005-09-01

    The zinc concentration of siliceous sponge spicules was determined from spicules recovered from four sediment cores spanning the last 160 kyr, from the Campbell Plateau region southeast of New Zealand. Zinc/Si results showed little difference between Holocene and glacial aged spicules. An increase in Zn/Si was observed for core Y14, where Zn/Si peaked at about 0.6 μmol/mol during marine isotope stages 5a-5b. To better understand the role carbon export has on sponge Zn/Si, we explored the strong relationship observed between surficial sediment particulate organic carbon (POC) and the Zn/Si of sponge silica and related this to sediment trap POC flux estimates. Conversion of the Zn/Si records to benthic POC fluxes suggests that there has been little change in the amount of POC reaching Campbell Plateau sediments over the past 30 kyr. These results suggest that surface productivity over the Campbell Plateau has remained relatively low over the past 160 kyr and suggests that glacial productivity was not significantly higher than the present day. Finally, this work reveals that living marine sponges appear to act as the biological equivalents of moored sediment traps, recording the flux of POC to the seafloor by archiving zinc associated with sinking POC in the growing silica skeleton.

  5. Stimulating endogenous cardiac repair

    PubMed Central

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  6. A rapid and general assay for monitoring endogenous gene modification.

    PubMed

    Guschin, Dmitry Y; Waite, Adam J; Katibah, George E; Miller, Jeffrey C; Holmes, Michael C; Rebar, Edward J

    2010-01-01

    The development of zinc finger nucleases for targeted gene modification can benefit from rapid functional assays that directly quantify activity at the endogenous target. Here we describe a simple procedure for quantifying mutations that result from DNA double-strand break repair via non-homologous end joining. The assay is based on the ability of the Surveyor nuclease to selectively cleave distorted duplex DNA formed via cross-annealing of mutated and wild-type sequence. PMID:20680839

  7. Symptomatic zinc deficiency in experimental zinc deprivation.

    PubMed Central

    Taylor, C M; Goode, H F; Aggett, P J; Bremner, I; Walker, B E; Kelleher, J

    1992-01-01

    An evaluation of indices of poor zinc status was undertaken in five male subjects in whom dietary zinc intake was reduced from 85 mumol d-1 in an initial phase of the study to 14 mumol d-1. One of the subjects developed features consistent with zinc deficiency after receiving the low zinc diet for 12 days. These features included retroauricular acneform macullo-papular lesions on the face, neck, and shoulders and reductions in plasma zinc, red blood cell zinc, neutrophil zinc and plasma alkaline phosphatase activity. Alcohol induced hepatitis, which was suspected in this subject, may have caused a predisposition to altered zinc metabolism and possible zinc deficiency which was exacerbated by subsequent zinc deprivation. The report supports the value of neutrophil zinc concentration as an indicator of poor zinc status. PMID:1740525

  8. Mammalian Endogenous Retroviruses.

    PubMed

    Mager, Dixie L; Stoye, Jonathan P

    2015-02-01

    Over 40% of mammalian genomes comprise the products of reverse transcription. Among such retrotransposed sequences are those characterized by the presence of long terminal repeats (LTRs), including the endogenous retroviruses (ERVs), which are inherited genetic elements closely resembling the proviruses formed following exogenous retrovirus infection. Sequences derived from ERVs make up at least 8 to 10% of the human and mouse genomes and range from ancient sequences that predate mammalian divergence to elements that are currently still active. In this chapter we describe the discovery, classification and origins of ERVs in mammals and consider cellular mechanisms that have evolved to control their expression. We also discuss the negative effects of ERVs as agents of genetic disease and cancer and review examples of ERV protein domestication to serve host functions, as in placental development. Finally, we address growing evidence that the gene regulatory potential of ERV LTRs has been exploited multiple times during evolution to regulate genes and gene networks. Thus, although recently endogenized retroviral elements are often pathogenic, those that survive the forces of negative selection become neutral components of the host genome or can be harnessed to serve beneficial roles. PMID:26104559

  9. Zinc cyanide

    Integrated Risk Information System (IRIS)

    Zinc cyanide ; CASRN 557 - 21 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effe

  10. Zinc phosphide

    Integrated Risk Information System (IRIS)

    Zinc phoshide ; CASRN 1314 - 84 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  11. Zinc interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most common and probably the most harmful micronutrient deficiency of commercial pecan enterprises is zinc deficiency. A review is presented of how orchard nutrient element management practices potentially influence tree Zn nutrition. Findings provide background information on how to reduce th...

  12. The Essential Toxin: Impact of Zinc on Human Health

    PubMed Central

    Plum, Laura M.; Rink, Lothar; Haase, Hajo

    2010-01-01

    Compared to several other metal ions with similar chemical properties, zinc is relatively harmless. Only exposure to high doses has toxic effects, making acute zinc intoxication a rare event. In addition to acute intoxication, long-term, high-dose zinc supplementation interferes with the uptake of copper. Hence, many of its toxic effects are in fact due to copper deficiency. While systemic homeostasis and efficient regulatory mechanisms on the cellular level generally prevent the uptake of cytotoxic doses of exogenous zinc, endogenous zinc plays a significant role in cytotoxic events in single cells. Here, zinc influences apoptosis by acting on several molecular regulators of programmed cell death, including caspases and proteins from the Bcl and Bax families. One organ where zinc is prominently involved in cell death is the brain, and cytotoxicity in consequence of ischemia or trauma involves the accumulation of free zinc. Rather than being a toxic metal ion, zinc is an essential trace element. Whereas intoxication by excessive exposure is rare, zinc deficiency is widespread and has a detrimental impact on growth, neuronal development, and immunity, and in severe cases its consequences are lethal. Zinc deficiency caused by malnutrition and foods with low bioavailability, aging, certain diseases, or deregulated homeostasis is a far more common risk to human health than intoxication. PMID:20617034

  13. Endogenous pulmonary antibiotics.

    PubMed

    Gibbons, M A; Bowdish, D M; Davidson, D J; Sallenave, J M; Simpson, A J

    2006-05-01

    The human lung produces a variety of peptides and proteins which have intrinsic antimicrobial activity. In general these molecules have broad spectra of antimicrobial activity, kill micro-organisms rapidly, and evade resistance generated by pathogens. In recent years it has become increasingly apparent that the antimicrobial peptides (AMPs) simultaneously possess immunomodulatory functions, suggesting complex roles for these molecules in regulating the clearance of, and immune response to, invading pathogens. These collective properties have stimulated considerable interest in the potential clinical application of endogenous AMPs. This article outlines the biology of AMPs, their pattern of expression in the lung, and their functions, with reference to both antimicrobial and immunomodulatory activity. We then consider the biological importance of AMPs, before concentrating on the potential to use AMPs to therapeutic effect. The principles discussed in the article apply to innate immune defence throughout the body, but particular emphasis is placed on AMPs in the lung and the potential application to pulmonary infection. PMID:16722137

  14. The Relevance of the Colon to Zinc Nutrition

    PubMed Central

    Gopalsamy, Geetha Lavaniya; Alpers, David H; Binder, Henry J; Tran, Cuong D; Ramakrishna, B S; Brown, Ian; Manary, Mark; Mortimer, Elissa; Young, Graeme P

    2015-01-01

    Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income countries. Apart from inadequate dietary intake of bioavailable zinc, other significant contributors to zinc deficiency include the excessive intestinal loss of endogenously secreted zinc and impairment in small intestinal absorptive function. Such changes are likely to occur in children suffering from environmental (or tropical) enteropathy (EE)—an almost universal condition among inhabitants of developing countries characterized by morphologic and functional changes in the small intestine. Changes to the proximal gut in environmental enteropathy will likely influence the nature and amount of zinc delivered into the large intestine. Consequently, we reviewed the current literature to determine if colonic absorption of endogenous or exogenous (dietary) zinc could contribute to overall zinc nutriture. Whilst we found evidence that significant zinc absorption occurs in the rodent colon, and is favoured when microbially-fermentable carbohydrates (specifically resistant starch) are consumed, it is unclear whether this process occur in humans and/or to what degree. Constraints in study design in the few available studies may well have masked a possible colonic contribution to zinc nutrition. Furthermore these few available human studies have failed to include the actual target population that would benefit, namely infants affected by EE where zinc delivery to the colon may be increased and who are also at risk of zinc deficiency. In conducting this review we have not been able to confirm a colonic contribution to zinc absorption in humans. However, given the observations in rodents and that feeding resistant starch to children is feasible, definitive studies utilising the dual stable isotope method in children with EE should be undertaken. PMID:25594440

  15. Rechargeable nickel-zinc batteries

    NASA Technical Reports Server (NTRS)

    Soltis, D. G.

    1977-01-01

    Device proves superiority in having two and one half to three times the energy content of popular lead-zinc or nickel-cadmium batteries. Application to electric utility vehicles improved acceleration rate and nearly doubled driving range between rechargings. Unit contributes substantially toward realization of practical urban electrical automobiles.

  16. Higher Bioavailability of Organic Bound Zinc from High Zinc-Enriched Fungi.

    PubMed

    Zhang, Xin-Guo; Peng, Yi-Nan; Li, Xiao-Ru; Ma, Guo-Di; Wang, Ming-Gang

    2014-01-01

    The organic forms of trace elements are considered more bioavailable than the inorganic forms. Although yeast can enrich metal elements and convert inorganic zinc to organic species, its tolerability and transforming capacity are limited. It would therefore be very interesting to look for higher conversion and accumulation in zinc fungi to obtain organic bound zinc from the natural environment. In this paper, potato dextrose agar (PDA) medium containing 800 μg/mL zinc was used for initial screening, with twenty-two fungal strains that tolerated high zinc isolated from the natural environment, and one strain (No.LZ-1108) growing well at a zinc (II) concentration of 10,000 μg/mL. According to morphological analysis, 18S rDNA sequence analysis, and biophysical and biochemical characteristics, No.LZ-1108 was tentatively identified as Fusarium oxysporum. Using atomic absorption spectrometry, the zinc content in the No.LZ-1108 cells was found to be 6.7 mg/g dry cell. After oral administration to rats at a dose of 10 mg Zn (II)/kg body weight, the area under the plasma concentration-time curve (AUC) and the maximum zinc blood concentration (Cmax) of No.LZ-1108 and zinc gluconate were 8.10 g/L.min and 4.28 g/L.min, 23.72 μg/mL and 6.23 μg/mL, respectively. The AUC of No.LZ-1108 was significantly higher than those of zinc gluconate (P<0.05), and the mean relative bioavailability of AUC(test)/AUC(zinc gluconate) was 190 %, which showed that the bound zinc in No.LZ-1108 was more bioavailable than zinc gluconate. The present study reports an interesting alternative to developing zinc-based supplements from a natural source of zinc. PMID:26255549

  17. Zinc Competition among the Intestinal Microbiota

    PubMed Central

    Gielda, Lindsay M.; DiRita, Victor J.

    2012-01-01

    ABSTRACT Bioavailable levels of trace metals, such as iron and zinc, for bacterial growth in nature are sufficiently low that most microbes have evolved high-affinity binding and transport systems. The microbe Campylobacter jejuni lives in the gastrointestinal tract of chickens, the principal source of human infection. A high-affinity ABC transporter for zinc uptake is required for Campylobacter survival in chicken intestines in the presence of a normal microbiota but not when chickens are raised with a limited microbiota. Mass spectrometric analysis of cecal contents revealed the presence of numerous zinc-binding proteins in conventional chicks compared to the number in limited-microbiota chicks. The presence of a microbiota results in the production of host zinc-binding enzymes, causing a growth restriction for bacteria that lack the high-affinity zinc transporter. Such transporters in a wide range of pathogenic bacteria make them good targets for the development of broad-spectrum antimicrobials. Importance Zinc is an essential trace element for the growth of most organisms. Quantities of zinc inside cells are highly regulated, as too little zinc does not support growth, while too much zinc is toxic. Numerous bacterial cells require zinc uptake systems for growth and virulence. The work presented here demonstrates that the microbiota in the gastrointestinal tract reduces the quantity of zinc. Without a high-affinity zinc transporter, Campylobacter jejuni, a commensal organism of chickens, is unable to replicate or colonize the gastrointestinal tract. This is the first demonstration of zinc competition between microbiota in the gastrointestinal tract of a host. These results could have profound implications in the field of microbial pathogenesis and in our understanding of host metabolism and the microbiota. PMID:22851657

  18. Food survey: levels and potential health risks of chromium, lead, zinc and copper content in fruits and vegetables consumed in Algeria.

    PubMed

    Cherfi, Abdelhamid; Abdoun, Samira; Gaci, Ouardia

    2014-08-01

    A food survey was carried out with the aim to investigate the levels of lead (Pb), zinc (Zn), copper (Cu) and chromium (Cr) in various fruits and vegetables sold in Algeria. Concentrations (mg/kgdry wt.) in selected foodstuffs were detected within the following ranges: 4-29.49, 11.17-49, 12.33-39.33 and 3-16.33 for Cu, Zn, Pb and Cr respectively. The food ingestion rate of the selected items was investigated by self-administered questionnaires which were filled by a total of 843 people randomly recruited at the exit of markets. The potential health risk for consumers was investigated by estimating the daily intake (EDI) and the target hazard quotient (THQ) for each heavy metal. For all foodstuffs, the EDI and the THQ were below the threshold values for Cu, Zn and Cr while they exceeded the thresholds for Pb (EDI: 15.66μgPb/kg body weight/day; THQ: 4.37), indicating an obvious health risk over a life time of exposure. PMID:24815819

  19. [Endogenous bacterial endophthalmitis].

    PubMed

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  20. Endogenous strategy in exploration.

    PubMed

    Solman, Grayden J F; Kingstone, Alan

    2015-12-01

    We examined the characteristics of endogenous exploratory behaviors in a generalized search task in which guidance signals (e.g., landmarks, semantics, visual saliency, layout) were limited or precluded. Individuals looked for the highest valued cell in an array and were scored on the quality of the best value they could find. Exploration was guided only by the cells that had been previously examined, and the value of this guidance was manipulated by adjusting spatial autocorrelation to produce relatively smooth and rough landscapes-that is, arrays in which nearby cells had unrelated values (low correlation = rough) or similar values (high correlation = smooth). For search in increasingly rough as compared with smooth arrays, we found reduced performance despite increased sampling and increased time spent searching after revelation of a searcher's best cell. Spatially, sampling strategies tended toward more excursive, branching, and space-filling patterns as correlation decreased. Using a novel generalized-recurrence analysis, we report that these patterns reflect an increase in systematic search paths, characterized by regularized sweeps with localized infilling. These tendencies were likewise enhanced for high-performance as compared with low-performance participants. The results suggest a trade-off between guidance (in smooth arrays) and systematicity (in rough arrays), and they provide insight into the particular strategic approaches adopted by searchers when exogenous guiding information is minimized. PMID:26214501

  1. Radioisotopic studies concerning the efficacy of standard washing procedures for the cleansing of hair before zinc analysis

    SciTech Connect

    Buckley, R.A.; Dreosti, I.E.

    1984-10-01

    Various standard procedures were investigated in relation to the removal of exogenously applied 65Zn from human hair and endogenously incorporated 65Zn from rat hair. Human hair was found to adsorb zinc and a variety of other metal ions from aqueous solutions in a manner which suggested some ion-exchange capacity. Uptake of zinc varied considerably between human hair samples, but in most cases accumulation of zinc occurred rapidly and often resulted in hair zinc levels several-fold higher than found in control samples. Extraction of zinc and other metal ions was greatest after treatment with disodium EDTA and sodium lauryl sulfate than after washing with water or aqueous Triton X-100. However, no procedure effectively removed all exogenous zinc, while all treatments extracted varying proportions of the endogenous zinc component. Because of the inability of standard washing procedures to remove exogenous zinc without reducing endogenous or indicator zinc levels, use of hair zinc analyses to indicate nutritional zinc status are inadvisable if hair zinc contamination is likely to have occurred.

  2. Zinc in diet

    MedlinePlus

    Animal proteins are a good source of zinc. Beef, pork, and lamb contain more zinc than fish. The ... use by the body as the zinc from animal proteins. Therefore, low-protein diets and vegetarian diets tend ...

  3. Zinc asparaginate supplementation induces redistribution of toxic trace elements in rat tissues and organs

    PubMed Central

    Skalny, Andrey A.; Medvedeva, Yulia S.; Alchinova, Irina B.; Karganov, Mikhail Yu.; Ajsuvakova, Olga P.; Skalny, Anatoly V.; Nikonorov, Alexandr A.

    2015-01-01

    The primary objective of the current study was the investigation of the influence of zinc asparaginate supplementation for 7 and 14 days on toxic metal and metalloid content in rat organs and tissues. Rats obtained zinc asparaginate in doses of 5 and 15 mg/kg/day for 7 and 14 days. At the end of the experiment rat tissues and organs (liver, kidney, heart, m. gastrocnemius, serum, and hair) were collected for subsequent analysis. Estimation of Zn, Al, As, Li, Ni, Sn, Sr content in the harvested organs was performed using inductively coupled plasma mass spectrometry at NexION 300D. The obtained data showed that intragastric administration of zinc significantly increased liver, kidney and serum zinc concentrations. Seven-day zinc treatment significantly affected the toxic trace element content in the animals’ organs. Zinc supplementation significantly decreased particularly liver aluminium, nickel, and tin content, whereas lead tended to increase. Zinc-induced changes in kidney metal content were characterized by elevated lithium and decreased nickel concentration. Zinc-induced alteration of myocardical toxic element content was multidirectional. Muscle aluminium and lead concentration were reduced in response to zinc supplementation. At the same time, serum and hair toxic element concentrations remained relatively stable after 7-day zinc treatment. Zinc asparaginate treatment of 14 days significantly depressed liver and elevated kidney lithium content, whereas a significant zinc-associated decrease was detected in kidney strontium content. Zinc supplementation for 14 days resulted also in multidirectional changes in the content of heart toxic elements. At the same time, significant zinc-associated decrease in muscle lithium and nickel levels was observed. Fourteen-day zinc treatment resulted in significantly increased serum arsenic and tin concentrations, whereas hair trace element content remained relatively stable. Generally, the obtained data indicate a

  4. Zinc asparaginate supplementation induces redistribution of toxic trace elements in rat tissues and organs.

    PubMed

    Skalny, Andrey A; Tinkov, Alexey A; Medvedeva, Yulia S; Alchinova, Irina B; Karganov, Mikhail Yu; Ajsuvakova, Olga P; Skalny, Anatoly V; Nikonorov, Alexandr A

    2015-09-01

    The primary objective of the current study was the investigation of the influence of zinc asparaginate supplementation for 7 and 14 days on toxic metal and metalloid content in rat organs and tissues. Rats obtained zinc asparaginate in doses of 5 and 15 mg/kg/day for 7 and 14 days. At the end of the experiment rat tissues and organs (liver, kidney, heart, m. gastrocnemius, serum, and hair) were collected for subsequent analysis. Estimation of Zn, Al, As, Li, Ni, Sn, Sr content in the harvested organs was performed using inductively coupled plasma mass spectrometry at NexION 300D. The obtained data showed that intragastric administration of zinc significantly increased liver, kidney and serum zinc concentrations. Seven-day zinc treatment significantly affected the toxic trace element content in the animals' organs. Zinc supplementation significantly decreased particularly liver aluminium, nickel, and tin content, whereas lead tended to increase. Zinc-induced changes in kidney metal content were characterized by elevated lithium and decreased nickel concentration. Zinc-induced alteration of myocardical toxic element content was multidirectional. Muscle aluminium and lead concentration were reduced in response to zinc supplementation. At the same time, serum and hair toxic element concentrations remained relatively stable after 7-day zinc treatment. Zinc asparaginate treatment of 14 days significantly depressed liver and elevated kidney lithium content, whereas a significant zinc-associated decrease was detected in kidney strontium content. Zinc supplementation for 14 days resulted also in multidirectional changes in the content of heart toxic elements. At the same time, significant zinc-associated decrease in muscle lithium and nickel levels was observed. Fourteen-day zinc treatment resulted in significantly increased serum arsenic and tin concentrations, whereas hair trace element content remained relatively stable. Generally, the obtained data indicate a

  5. Effect of zinc concentration on the activity of angiotensin converting enzyme in human plasma and serum

    SciTech Connect

    Reeves, P.G.; Carl, G.F.; Smith, D.K.; O'Dell, B.L.

    1986-03-05

    The activity of angiotensin converting enzyme is measured clinically to assist in the diagnosis of sarcoidosis and to monitor therapy with steroids, and with antihypertensive drugs that inhibit the enzyme. Even though it has been known for some time that ACE is a zinc dependent enzyme, it was discovered only recently that zinc, in addition to endogenous levels in the assay mixture, is required for maximal activity of rat serum ACE. The present experiment was designed to determine if additional zinc is required for maximal activation of ACE in plasma and serum of human subjects. Plasma or serum samples were incubated at 37/sup 0/ in a zinc-free medium, pH 7.4, containing hippurylglyclglycine as the substrate. The addition of 20 ..mu..M zinc significantly increased ACE activity in plasma (95.4 +/- 11.9 vs 192.8 +/- 24.3 U/L) and in serum (89.9 +/- 5.6 vs 195.7 +/- 9.3 U/L) compared to samples without added zinc. Enzyme activity was increased 2.4-fold when zinc was added to plasma from a patient with low plasma zinc. These data suggest that the endogenous level of zinc in the assay mixture resulting from the addition of an aliquot of plasma or serum is insufficient to obtain maximal activity of ACE. The addition of zinc to zinc deficient plasma increased ACE activity even more.

  6. Mass fractions of 52 trace elements and zinc/trace element content ratios in intact human prostates investigated by inductively coupled plasma mass spectrometry.

    PubMed

    Zaichick, Sofia; Zaichick, Vladimir; Nosenko, Sergey; Moskvina, Irina

    2012-11-01

    Contents of 52 trace elements in intact prostate of 64 apparently healthy 13-60-year-old men (mean age 36.5 years) were investigated by inductively coupled plasma mass spectrometry. Mean values (M ± SΕΜ) for mass fraction (in milligrams per kilogram, on dry-weight basis) of trace elements were as follows: Ag 0.041 ± 0.005, Al 36 ± 4, Au 0.0039 ± 0.0007, B 0.97 ± 0.13, Be 0.00099 ± 0.00006, Bi 0.021 ± 0.008, Br 29 ± 3, Cd 0.78 ± 0.09, Ce 0.028 ± 0.004, Co 0.035 ± 0.003, Cs 0.034 ± 0.003, Dy 0.0031 ± 0.0005, Er 0.0018 ± 0.0004, Gd 0.0030 ± 0.0005, Hg 0.046 ± 0.006, Ho 0.00056 ± 0.00008, La 0.074 ± 0.015, Li 0.040 ± 0.004, Mn 1.53 ± 0.09, Mo 0.30 ± 0.03, Nb 0.0051 ± 0.0009, Nd 0.013 ± 0.002, Ni 4.3 ± 0.7, Pb 1.8 ± 0.4, Pr 0.0033 ± 0.0004, Rb 15.9 ± 0.6, Sb 0.040 ± 0.005, Se 0.73 ± 0.03, Sm 0.0027 ± 0.0004, Sn 0.25 ± 0.05, Tb 0.00043 ± 0.00009, Th 0.0024 ± 0.0005, Tl 0.0014 ± 0.0001, Tm 0.00030 ± 0.00006, U 0.0049 ± 0.0014, Y 0.019 ± 0.003, Yb 0.0015 ± 0.0002, Zn 782 ± 97, and Zr 0.044 ± 0.009, respectively. The upper limit of mean contents of As, Cr, Eu, Ga, Hf, Ir, Lu, Pd, Pt, Re, Ta, and Ti were the following: As ≤ 0.018, Cr ≤ 0.64, Eu ≤ 0.0006, Ga ≤ 0.08, Hf ≤ 0.02, Ir ≤ 0.0004, Lu ≤ 0.00028, Pd ≤ 0.007, Pt ≤ 0.0009, Re ≤ 0.0015, Ta ≤ 0.005, and Ti ≤ 2.6. In all prostate samples, the content of Te was under detection limit (<0.003). Additionally, ratios of the Zn content to other trace element contents as well as correlations between Zn and trace elements were calculated. Our data indicate that the human prostate accumulates such trace elements as Al, Au, B, Br, Cd, Cr, Ga, Li, Mn, Ni, Pb, U, and Zn. No special relationship between Zn and other trace elements was found. PMID:22549701

  7. Update on zinc biology.

    PubMed

    Solomons, Noel W

    2013-01-01

    Zinc has become a prominent nutrient of clinical and public health interest in the new millennium. Functions and actions for zinc emerge as increasingly ubiquitous in mammalian anatomy, physiology and metabolism. There is undoubtedly an underpinning in fundamental biology for all of the aspects of zinc in human health (clinical and epidemiological) in pediatric and public health practice. Unfortunately, basic science research may not have achieved a full understanding as yet. As a complement to the applied themes in the companion articles, a selection of recent advances in the domains homeostatic regulation and transport of zinc is presented; they are integrated, in turn, with findings on genetic expression, intracellular signaling, immunity and host defense, and bone growth. The elements include ionic zinc, zinc transporters, metallothioneins, zinc metalloenzymes and zinc finger proteins. In emerging basic research, we find some plausible mechanistic explanations for delayed linear growth with zinc deficiency and increased infectious disease resistance with zinc supplementation. PMID:23689109

  8. Production of zinc pellets

    SciTech Connect

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  9. Production of zinc pellets

    DOEpatents

    Cooper, John F.

    1996-01-01

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries.

  10. Gravity effects on endogenous movements

    NASA Astrophysics Data System (ADS)

    Johnsson, Anders; Antonsen, Frank

    Gravity effects on endogenous movements A. Johnsson * and F. Antonsen *+ * Department of Physics, Norwegian University of Science and Technology,NO-7491, Trond-heim, Norway, E-mail: anders.johnsson@ntnu.no + Present address: Statoil Research Center Trondheim, NO-7005, Trondheim, Norway Circumnutations in stems/shoots exist in many plants and often consists of more or less regular helical movements around the plumb line under Earth conditions. Recent results on circumnu-tations of Arabidopsis in space (Johnsson et al. 2009) showed that minute amplitude oscilla-tions exist in weightlessness, but that centripetal acceleration (mimicking the gravity) amplified and/or created large amplitude oscillations. Fundamental mechanisms underlying these results will be discussed by modeling the plant tissue as a cylinder of cells coupled together. As a starting point we have modeled (Antonsen 1998) standing waves on a ring of biological cells, as first discussed in a classical paper (Turing 1952). If the coupled cells can change their water content, an `extension' wave could move around the ring. We have studied several, stacked rings of cells coupled into a cylinder that together represent a cylindrical plant tissue. Waves of extensions travelling around the cylinder could then represent the observable circumnutations. The coupling between cells can be due to cell-to-cell diffusion, or to transport via channels, and the coupling can be modeled to vary in both longitudinal and transversal direction of the cylinder. The results from ISS experiments indicate that this cylindrical model of coupled cells should be able to 1) show self-sustained oscillations without the impact of gravity (being en-dogenous) and 2) show how an environmental factor like gravity can amplify or generate the oscillatory movements. Gravity has been introduced in the model by a negative, time-delayed feed-back transport across the cylinder. This represents the physiological reactions to acceler

  11. RNA-Seq Analysis of the Effect of Kanamycin and the ABC Transporter AtWBC19 on Arabidopsis thaliana Seedlings Reveals Changes in Metal Content

    PubMed Central

    Mentewab, Ayalew; Matheson, Kinnari; Adebiyi, Morayo; Robinson, Shanice; Elston, Brianna

    2014-01-01

    Plants are exposed to antibiotics produced by soil microorganisms, but little is known about their responses at the transcriptional level. Likewise, few endogenous mechanisms of antibiotic resistance have been reported. The Arabidopsis thaliana ATP Binding Cassette (ABC) transporter AtWBC19 (ABCG19) is known to confer kanamycin resistance, but the exact mechanism of resistance is not well understood. Here we examined the transcriptomes of control seedlings and wbc19 mutant seedlings using RNA-seq analysis. Exposure to kanamycin indicated changes in the organization of the photosynthetic apparatus, metabolic fluxes and metal uptake. Elemental analysis showed a 60% and 80% reduction of iron uptake in control and wbc19 mutant seedlings respectively, upon exposure to kanamycin. The drop in iron content was accompanied by the upregulation of the gene encoding for FERRIC REDUCTION OXIDASE 6 (FRO6) in mutant seedlings but not by the differential expression of other transport genes known to be induced by iron deficiency. In addition, wbc19 mutants displayed a distinct expression profile in the absence of kanamycin. Most notably the expression of several zinc ion binding proteins, including ZINC TRANSPORTER 1 PRECURSOR (ZIP1) was increased, suggesting abnormal zinc uptake. Elemental analysis confirmed a 50% decrease of zinc content in wbc19 mutants. Thus, the antibiotic resistance gene WBC19 appears to also have a role in zinc uptake. PMID:25310285

  12. RNA-seq analysis of the effect of kanamycin and the ABC transporter AtWBC19 on Arabidopsis thaliana seedlings reveals changes in metal content.

    PubMed

    Mentewab, Ayalew; Matheson, Kinnari; Adebiyi, Morayo; Robinson, Shanice; Elston, Brianna

    2014-01-01

    Plants are exposed to antibiotics produced by soil microorganisms, but little is known about their responses at the transcriptional level. Likewise, few endogenous mechanisms of antibiotic resistance have been reported. The Arabidopsis thaliana ATP Binding Cassette (ABC) transporter AtWBC19 (ABCG19) is known to confer kanamycin resistance, but the exact mechanism of resistance is not well understood. Here we examined the transcriptomes of control seedlings and wbc19 mutant seedlings using RNA-seq analysis. Exposure to kanamycin indicated changes in the organization of the photosynthetic apparatus, metabolic fluxes and metal uptake. Elemental analysis showed a 60% and 80% reduction of iron uptake in control and wbc19 mutant seedlings respectively, upon exposure to kanamycin. The drop in iron content was accompanied by the upregulation of the gene encoding for FERRIC REDUCTION OXIDASE 6 (FRO6) in mutant seedlings but not by the differential expression of other transport genes known to be induced by iron deficiency. In addition, wbc19 mutants displayed a distinct expression profile in the absence of kanamycin. Most notably the expression of several zinc ion binding proteins, including ZINC TRANSPORTER 1 PRECURSOR (ZIP1) was increased, suggesting abnormal zinc uptake. Elemental analysis confirmed a 50% decrease of zinc content in wbc19 mutants. Thus, the antibiotic resistance gene WBC19 appears to also have a role in zinc uptake. PMID:25310285

  13. Endogenous rhythms influence interpersonal synchrony.

    PubMed

    Zamm, Anna; Wellman, Chelsea; Palmer, Caroline

    2016-05-01

    Interpersonal synchrony, the temporal coordination of actions between individuals, is fundamental to social behaviors from conversational speech to dance and music-making. Animal models indicate constraints on synchrony that arise from endogenous rhythms: Intrinsic periodic behaviors or processes that continue in the absence of change in external stimulus conditions. We report evidence for a direct causal link between endogenous rhythms and interpersonal synchrony in a music performance task, which places high demands on temporal coordination. We first establish that endogenous rhythms, measured by spontaneous rates of individual performance, are stable within individuals across stimulus materials, limb movements, and time points. We then test a causal link between endogenous rhythms and interpersonal synchrony by pairing each musician with a partner who is either matched or mismatched in spontaneous rate and by measuring their joint behavior up to 1 year later. Partners performed melodies together, using either the same or different hands. Partners who were matched for spontaneous rate showed greater interpersonal synchrony in joint performance than mismatched partners, regardless of hand used. Endogenous rhythms offer potential to predict optimal group membership in joint behaviors that require temporal coordination. (PsycINFO Database Record PMID:26820249

  14. Synthesis and characterization of amylose-zinc inclusion complexes.

    PubMed

    Luo, Zhigang; Zou, Jinfeng; Chen, Haiming; Cheng, Weiwei; Fu, Xiong; Xiao, Zhigang

    2016-02-10

    Amylose-zinc inclusion complexes were synthesized using zinc chloride and amylose, which is obtained by completely debranching potato starch using pullulanase. Based on the zinc content (W-Zn) and zinc conversion (C-Zn), the reaction parameters, such as reaction time, reaction temperature, pH value and amount of zinc chloride added, were evaluated. The W-Zn and C-Zn of the zinc-loaded amylose, which was prepared under optimal conditions, were 128 mg/g and 82.05%, respectively. The Raman spectra showed that amylose formed a special single helix structure after complexing with zinc. X-Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) results showed that starch and zinc could formate the inclusion complexes. Moreover, the formation of amylose-zinc inclusion complexes was confirmed by the results of X-ray photoelectron spectroscopy (XPS) and (13)C CP/MAS NMR, which suggests that zinc was mainly coordinated to the oxygen atoms of the glucose unit, 6-CH2OH. Thermal properties of the complexes were influenced by the zincatation process. This approach not only enlarged the number of fields for amylose use but also exhibited the extensive potential applications for zinc nutrition fortifier research. The study suggested that potato amylose might be a good carrier of zinc for nutritional supplementation purposes. PMID:26686135

  15. Transient neonatal zinc deficiency.

    PubMed

    Krieger, I; Alpern, B E; Cunnane, S C

    1986-06-01

    We report an infant who developed clinical manifestations of zinc deficiency during the first month of life although the diet was adequate for zinc and no other causes could be ascertained. The diagnosis was confirmed by low plasma-zinc concentrations and a positive response to zinc treatment. The fatty acid profile of plasma phospholipids was typical of zinc deficiency (ie, arachidonic acid was markedly decreased). The transient nature of this disorder was evident when no relapse occurred after cessation of zinc therapy and plasma-zinc and arachidonic acid concentrations remained normal. Several explanations for the development of transient neonatal zinc deficiency are offered. The observation demonstrates that occasional infants may have requirements for zinc that are beyond the intakes of the conventional RDA. PMID:3717070

  16. Impact of the discovery of human zinc deficiency on health.

    PubMed

    Prasad, Ananda S

    2009-06-01

    The essentiality of zinc was recognized 46 years ago. Zinc deficiency resulting in growth retardation, hypogonadism, immune dysfunction and cognitive impairment affects nearly 2 billion subjects in the developing world. High phytate content of the cereal proteins consumed in the developing world, results in decreased availability of zinc for absorption. Zinc therapy has been very successful and life saving measure in patients with acrodermatitis enteropathica and Wilson's disease. Beneficial therapeutic responses of zinc supplementation have been ovserved in acute diarrhea in children, chronic hepatitis C, shigellosis, leprosy, leishmaniasis, and common cold. Zinc supplementation was effective in decreasing incidences of infection in elderly and patients with sickle cell disease. Zinc supplementation was effective in preventing blindness in 25% of the elderly with dry type of age related macular degeneration. Zinc supplementation in the elderly decreased oxidative stress and decreased generation of inflammatory cytokines. Zinc is an intracellular signaling molecule in monocytes, dendritic cells and macrophages and it plays an important role in cell-mediated immune functions and oxidative stress. Zinc is also an anti-inflammatory agent. These unique properties of zinc may have significant therapeutic benefits in several diseases in humans. In many diseases concurrent zinc deficiency may complicate the clinical features, affect adversely immunological status, increase oxidative stress and increase generation of inflammatory cytokines. Oxidative stress and chronic inflammation may play important causative roles in many chronic diseases, including atherosclerosis, several malignancies, neurological disorders, and auto-immune diseases. It is therefore, important that status of zinc is assessed and zinc deficiency corrected in these chronic diseases. A controlled clinical trial of zinc supplementation in these disorders in order to document the preventive and therapeutic

  17. Nematode endogenous small RNA pathways

    PubMed Central

    Hoogstrate, Suzanne W; Volkers, Rita JM; Sterken, Mark G; Kammenga, Jan E; Snoek, L Basten

    2014-01-01

    The discovery of small RNA silencing pathways has greatly extended our knowledge of gene regulation. Small RNAs have been presumed to play a role in every field of biology because they affect many biological processes via regulation of gene expression and chromatin remodeling. Most well-known examples of affected processes are development, fertility, and maintenance of genome stability. Here we review the role of the three main endogenous small RNA silencing pathways in Caenorhabditis elegans: microRNAs, endogenous small interfering RNAs, and PIWI-interacting RNAs. After providing an entry-level overview on how these pathways function, we discuss research on other nematode species providing insight into the evolution of these small RNA pathways. In understanding the differences between the endogenous small RNA pathways and their evolution, a more comprehensive picture is formed of the functions and effects of small RNAs. PMID:25340013

  18. Quantitative analysis of endogenous compounds.

    PubMed

    Thakare, Rhishikesh; Chhonker, Yashpal S; Gautam, Nagsen; Alamoudi, Jawaher Abdullah; Alnouti, Yazen

    2016-09-01

    Accurate quantitative analysis of endogenous analytes is essential for several clinical and non-clinical applications. LC-MS/MS is the technique of choice for quantitative analyses. Absolute quantification by LC/MS requires preparing standard curves in the same matrix as the study samples so that the matrix effect and the extraction efficiency for analytes are the same in both the standard and study samples. However, by definition, analyte-free biological matrices do not exist for endogenous compounds. To address the lack of blank matrices for the quantification of endogenous compounds by LC-MS/MS, four approaches are used including the standard addition, the background subtraction, the surrogate matrix, and the surrogate analyte methods. This review article presents an overview these approaches, cite and summarize their applications, and compare their advantages and disadvantages. In addition, we discuss in details, validation requirements and compatibility with FDA guidelines to ensure method reliability in quantifying endogenous compounds. The standard addition, background subtraction, and the surrogate analyte approaches allow the use of the same matrix for the calibration curve as the one to be analyzed in the test samples. However, in the surrogate matrix approach, various matrices such as artificial, stripped, and neat matrices are used as surrogate matrices for the actual matrix of study samples. For the surrogate analyte approach, it is required to demonstrate similarity in matrix effect and recovery between surrogate and authentic endogenous analytes. Similarly, for the surrogate matrix approach, it is required to demonstrate similar matrix effect and extraction recovery in both the surrogate and original matrices. All these methods represent indirect approaches to quantify endogenous compounds and regardless of what approach is followed, it has to be shown that none of the validation criteria have been compromised due to the indirect analyses. PMID

  19. Endogenized viral sequences in mammals.

    PubMed

    Parrish, Nicholas F; Tomonaga, Keizo

    2016-06-01

    Reverse-transcribed RNA molecules compose a significant portion of the human genome. Many of these RNA molecules were retrovirus genomes either infecting germline cells or having done so in a previous generation but retaining transcriptional activity. This mechanism itself accounts for a quarter of the genomic sequence information of mammals for which there is data. We understand relatively little about the causes and consequences of retroviral endogenization. This review highlights functions ascribed to sequences of viral origin endogenized into mammalian genomes and suggests some of the most pressing questions raised by these observations. PMID:27128186

  20. Zinc enrichment of whole potato tuber by vacuum impregnation.

    PubMed

    Erihemu; Hironaka, Kazunori; Koaze, Hiroshi; Oda, Yuji; Shimada, Kenichiro

    2015-04-01

    Zinc is a nutritionally essential truce element, and thus zinc deficiency (ZD) severely affects human health. More than 25% of the world's population is at risk of ZD. This study was initiated to examine the use of the vacuum impregnation (VI) technique for enriching zinc content of whole potatoes; the effect of vacuum time, restoration time, steam-cooking and storage at 4 °C on the zinc content of VI whole potatoes was evaluated. Whole potato tubers were immersed in a 9 g/100 g zinc (zinc gluconate) solution. Vacuum pressure of 1,000 Pa was applied for 0-120 min, and atmospheric pressure restoration for 0-4 h. Experimental results showed that the zinc content of VI potatoes increased with vacuum and restoration time. Moreover, VI-cooked unpeeled or peeled potatoes had 63-94 times and 47-75 times higher zinc contents than un-VI-cooked unpeeled or peeled potatoes, respectively. The world daily potato consumption (86 g) of the VI-cooked unpeeled and peeled potatoes provided adult men with 130-148% and 100-135% of the recommended daily allowance (RDA) of zinc, respectively. Also, the daily potato consumption of the unpeeled and peeled potatoes supplied adult women with 178-203% and 137-185% of the RDA level, respectively. In addition, the VI potatoes had 40 times higher zinc contents through 30 days of storage at 4 °C, compared with un-VI-treated potatoes. This study indicated that VI treatment of whole potatoes was useful for enriching the zinc content. PMID:25829619

  1. Measurements of plasma zinc

    PubMed Central

    Davies, I. J. T.; Musa, M.; Dormandy, T. L.

    1968-01-01

    Zinc is an essential trace element. Previous methods of measuring zinc in clinical material have been difficult and reported findings must be treated with caution. Using atomic absorption spectroscopy it has been established that plasma zinc is one of the most uniform biochemical characteristics of normal adult blood. Sex and age differences in adult life are insignificant. Increased metabolic activity, on the other hand, induces a marked, immediate fall in plasma zinc level. The possible implications of this are discussed. Zinc levels in patients with diabetes mellitus, cardiovascular disease, and anaemia due to acute blood loss have been within normal limits. Plasma zinc is low in certain types of liver disease. PMID:5303355

  2. Deletion of the zupT gene for a zinc importer influences zinc pools in Cupriavidus metallidurans CH34.

    PubMed

    Herzberg, M; Bauer, L; Nies, D H

    2014-03-01

    Cupriavidus metallidurans strain CH34 accomplishes a high level of transition metal resistance by a combination of rather unspecific transition metal import and controlled efflux of surplus metals. Using the plasmid-free mutant strain AE104 that possesses only a limited number of metal efflux systems, cellular metal pools were identified as counterparts of these transport reactions. At low zinc concentrations strain AE104 took up Zn(II) until the zinc content reached an optimum level of 70,000 Zn(II) per cell in the exponential phase of growth, whereas a ΔzupT mutant lacking the zinc importer ZupT contained only 20,000 Zn(II)/cell, possibly the minimum zinc content. Mutant and parent cells accumulated up to 125,000 Zn(II) per cell at high (100 μM) external zinc concentrations (optimum zinc content). When the mutant strain Δe4, which has all the known genes for zinc efflux systems deleted, was cultivated in the presence of zinc concentrations close to its upper tolerance level (10 μM), these cells contained 250,000 Zn(II) per cell, probably the maximum zinc content. Instead of zinc, 120,000 cobalt or cadmium ions could also fill-up parts of this zinc pool, showing that it is in fact an undefined pool of divalent transition metal cations bound with low substrate specificity. Even when the cells contained sufficient numbers of total zinc, the zinc importer ZupT was required for important cellular processes, indicating the presence of a pool of tightly bound zinc ions, which depends on ZupT for efficient replenishment. The absence of ZupT led to the formation of inclusion bodies, perturbed oxidative stress resistance and decreased efficiency in the synthesis of the zinc-dependent subunit RpoC of the RNA polymerase, leading to RpoC accumulation. Moreover, when a czc allele for a zinc-exporting transenvelope efflux system CzcCBA was constitutively expressed in a ΔzupT mutant, this led to the disappearance of the CzcA protein and the central subunit of the protein

  3. [Zinc metabolism--a factor in canine aggression?].

    PubMed

    Juhr, Norbert-Christian; Brand, Ulrike; Behne, Dietrich

    2003-01-01

    In order to test the hypothesis of zinc-deficiency as a factor in canine aggression, we examined sera of dangerously aggressive dogs and of behaviourally normal (non-aggressive) dogs for their zinc-contents. The results showed distinctly higher zinc-concentrations (mean +/- SD) in aggressive dogs (1.69 +/- 0.49 micrograms/ml) than in normal non aggressive dogs (0.76 +/- 0.16 microgram/ml). PMID:12894678

  4. Zinc in Early Life: A Key Element in the Fetus and Preterm Neonate

    PubMed Central

    Terrin, Gianluca; Berni Canani, Roberto; Di Chiara, Maria; Pietravalle, Andrea; Aleandri, Vincenzo; Conte, Francesca; De Curtis, Mario

    2015-01-01

    Zinc is a key element for growth and development. In this narrative review, we focus on the role of dietary zinc in early life (including embryo, fetus and preterm neonate), analyzing consequences of zinc deficiency and adequacy of current recommendations on dietary zinc. We performed a systematic search of articles on the role of zinc in early life. We selected and analyzed 81 studies. Results of this analysis showed that preservation of zinc balance is of critical importance for the avoidance of possible consequences of low zinc levels on pre- and post-natal life. Insufficient quantities of zinc during embryogenesis may influence the final phenotype of all organs. Maternal zinc restriction during pregnancy influences fetal growth, while adequate zinc supplementation during pregnancy may result in a reduction of the risk of preterm birth. Preterm neonates are at particular risk to develop zinc deficiency due to a combination of different factors: (i) low body stores due to reduced time for placental transfer of zinc; (ii) increased endogenous losses; and (iii) marginal intake. Early diagnosis of zinc deficiency, through the measurement of serum zinc concentrations, may be essential to avoid severe prenatal and postnatal consequences in these patients. Typical clinical manifestations of zinc deficiency are growth impairment and dermatitis. Increasing data suggest that moderate zinc deficiency may have significant subclinical effects, increasing the risk of several complications typical of preterm neonates (i.e., necrotizing enterocolitis, chronic lung disease, and retinopathy), and that current recommended intakes should be revised to meet zinc requirements of extremely preterm neonates. Future studies evaluating the adequacy of current recommendations are advocated. PMID:26690476

  5. [Endogenous hyperlactatemia and insulin secretion].

    PubMed

    Ribes, G; Valette, G; Lignon, F; Loubatières-Mariani, M M

    1978-01-01

    In the normal anesthetized dog, the endogenous hyperlactatemia induced either by intense muscular work or by a high dose of phenformin (20 mg/kg subtucaneously) is followed by an increase in the pancreaticoduodenal insulin output. A previous perfusion of sodium dichloroacetate (50 mg/kg. h) opposes the hyperlactatemia, and reduces or suppresses the increase in insulin output. PMID:150887

  6. Total zinc in zinc battery plates by EDTA titration

    SciTech Connect

    Hammersley, V.L.

    1995-07-01

    At present, zinc battery plate electrodes are analyzed for zinc oxide, zinc chloride, zinc fluoride, zinc carbonate, zinc oxychloride, total zinc, zinc as the metal, and trace metals. A variety of methods are used to determine each of these components. The amount of zinc in each of the zinc compounds is determined by multiplying the percent of the compound by the ratio of the molecular weights of zinc to the zinc compound. This percent zinc is subtracted from percent total zinc and the operation is performed for every zinc compound determined. The remaining zinc value after these subtractions represents zinc as the metal. Zinc metal is the charged state on the anode. Percent total zinc is required in all these calculations. The importance of these components cannot be overemphasized. The presence, or absence, of certain components in the zinc electrode can influence its behavior in a zinc-silver oxide primary battery. Passivation layers, tendency to dendritic growth, corrosion rates, voltage rise times, current density, porosity, surface area, electrochemical capacity, and other considerations make it imperative that the chemical composition of the zinc electrode be known. The focus of this project was to evaluate the present method for total zinc and to develop a better method.

  7. Bacitracin zinc overdose

    MedlinePlus

    ... Small amounts of bacitracin zinc are dissolved in petroleum jelly to create antibiotic ointments. Bacitracin zinc overdose ... is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation ...

  8. Zinc oxide overdose

    MedlinePlus

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

  9. Bacitracin zinc overdose

    MedlinePlus

    Bacitracin zinc is a medicine that is used on cuts and other skin wounds to help prevent infection. Bacitracin ... medicine that kills germs. Small amounts of bacitracin zinc are dissolved in petroleum jelly to create antibiotic ...

  10. Drawing a fine line on endogenous retroelement activity

    PubMed Central

    Castro-Diaz, Nathaly; Friedli, Marc; Trono, Didier

    2015-01-01

    Endogenous retroelements (EREs) are essential motors of evolution yet require careful control to prevent genomic catastrophes, notably during the vulnerable phases of epigenetic reprogramming that occur immediately after fertilization and in germ cells. Accordingly, a variety of mechanisms restrict these mobile genetic units. Previous studies have revealed the importance of KRAB-containing zinc finger proteins (KRAB-ZFPs) and their cofactor, KAP1, in the early embryonic silencing of endogenous retroviruses and so-called SVAs, but the implication of this transcriptional repression system in the control of LINE-1, the only known active autonomous retrotransposon in the human genome, was thought to be marginal. Two recent studies straighten the record by revealing that the KRAB/KAP system is key to the control of L1 in embryonic stem (ES) cells, and go further in demonstrating that DNA methylation and KRAB/KAP1-induced repression contribute to this process in an evolutionally dynamic fashion. These results shed light on the delicate equilibrium between higher vertebrates and endogenous retroelements, which are not just genetic invaders calling for strict control but rather a constantly renewed and nicely exploitable source of evolutionary potential. PMID:26442176

  11. Zinc and gastrointestinal disease

    PubMed Central

    Skrovanek, Sonja; DiGuilio, Katherine; Bailey, Robert; Huntington, William; Urbas, Ryan; Mayilvaganan, Barani; Mercogliano, Giancarlo; Mullin, James M

    2014-01-01

    This review is a current summary of the role that both zinc deficiency and zinc supplementation can play in the etiology and therapy of a wide range of gastrointestinal diseases. The recent literature describing zinc action on gastrointestinal epithelial tight junctions and epithelial barrier function is described. Zinc enhancement of gastrointestinal epithelial barrier function may figure prominently in its potential therapeutic action in several gastrointestinal diseases. PMID:25400994

  12. ZINC ABSORPTION BY INFANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc is a vital mineral in human nutrition, and rare cases of overt zinc deficiency are well described in term and preterm infants. A variety of methods have been developed to assess zinc absorption, retention, and balance in humans, either using mass (metabolic) balance or stable isotope-based METH...

  13. The generation of zinc finger proteins by modular assembly

    PubMed Central

    Bhakta, Mital; Segal, David J.

    2015-01-01

    The modular assembly (MA) method of generating engineered zinc finger proteins (ZFPs) was the first practical method for creating custom DNA-binding proteins. As such, MA has enabled a vast exploration of sequence-specific methods and reagents, ushering in the modern era of zinc finger-based applications that are described in this volume. The first zinc finger nuclease to cleave an endogenous site was created using MA, as was the first artificial transcription factor to enter phase II clinical trials. In recent years, other excellent methods have been developed that improved the affinity and specificity of the engineered ZFPs. However, MA is still used widely for many applications. This chapter will describe methods and give guidance for the creation of ZFPs using MA. Such ZFPs might be useful as starting materials to perform other methods described in this volume. Here, we also describe a single-strand annealing recombination assay for the initial testing of zinc finger nucleases. PMID:20680825

  14. Endogenous opiates and behavior: 2014.

    PubMed

    Bodnar, Richard J

    2016-01-01

    This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular

  15. Small-Quantity Lipid-Based Nutrient Supplements, Regardless of Their Zinc Content, Increase Growth and Reduce the Prevalence of Stunting and Wasting in Young Burkinabe Children: A Cluster-Randomized Trial

    PubMed Central

    Hess, Sonja Y.; Abbeddou, Souheila; Jimenez, Elizabeth Yakes; Somé, Jérôme W.; Vosti, Stephen A.; Ouédraogo, Zinéwendé P.; Guissou, Rosemonde M.; Ouédraogo, Jean-Bosco; Brown, Kenneth H.

    2015-01-01

    Small-quantity lipid-based nutrient supplements (SQ-LNS) are promising home fortification products, but the optimal zinc level needed to improve growth and reduce morbidity is uncertain. We aimed to assess the impact of providing SQ-LNS with varied amounts of zinc, along with illness treatment, on zinc-related outcomes compared with standard care. In a placebo-controlled, cluster-randomized trial, 34 communities were stratified to intervention (IC) or non-intervention cohorts (NIC). 2435 eligible IC children were randomly assigned to one of four groups:1) SQ-LNS without zinc, placebo tablet; 2) SQ-LNS containing 5mg zinc, placebo tablet; 3) SQ-LNS containing 10mg zinc, placebo tablet; or 4) SQ-LNS without zinc and 5mg zinc tablet from 9–18 months of age. During weekly morbidity surveillance, oral rehydration salts were provided for reported diarrhea and antimalarial therapy for confirmed malaria. Children in NIC (n = 785) did not receive SQ-LNS, tablets, illness surveillance or treatment. At 9 and 18 months, length, weight and hemoglobin were measured in all children. Reported adherence was 97±6% for SQ-LNS and tablets. Mean baseline hemoglobin was 89±15g/L. At 18 months, change in hemoglobin was greater in IC than NIC (+8 vs -1g/L, p<0.0001), but 79.1% of IC were still anemic (vs. 91.1% in NIC). Final plasma zinc concentration did not differ by group. During the 9-month observation period, the incidence of diarrhea was 1.10±1.03 and of malaria 0.54±0.50 episodes per 100 child-days, and did not differ by group. Length at 18 months was significantly greater in IC compared to NIC (77.7±3.0 vs. 76.9±3.4cm; p<0.001) and stunting prevalence was significantly lower in IC (29.3%) than NIC (39.3%; p<0.0001), but did not differ by intervention group within IC. Wasting prevalence was also significantly lower in IC (8.7%) than in NIC (13.5%; p = 0.0003). Providing SQ-LNS daily with or without zinc, along with malaria and diarrhea treatment, significantly increased

  16. Zinc oxyfluoride transparent conductor

    DOEpatents

    Gordon, Roy G.

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  17. Endogenous respiration of Polyporus sulphureus

    SciTech Connect

    Li, S.M.W.; Siehr, D.J.

    1980-01-01

    Thirty percent of the dry weight of the basidiomycete Polyporus sulphureus is triterpenoid acid. The endogenous respiratory quotient of this organism is 0.8 indicating that the triterpenoid is being used as an endogenous storage material. Monosaccharides did not seem to be utilized as exogenous substrates but Krebs-cycle intermediates stimulated oxygen uptake. Pyruvic acid inhibited oxygen uptake. Studies with /sup 14/C-labeled glucose indicated that 27% of the glucose was metabolized by way of glycolysis. The hexose-monophosphate pathway was the major metabolic path for the utilization of glucose. Despite the fact that P. sulphureus is associated with brown rot, its carbon metabolism suggests that it utilizes substances associated with the degradation of lignin more readily than it does glucose.

  18. Endogenous Mechanisms of Cardiac Regeneration.

    PubMed

    Xiang, M S W; Kikuchi, K

    2016-01-01

    Zebrafish possess a remarkable capacity for cardiac regeneration throughout their lifetime, providing a model for investigating endogenous cellular and molecular mechanisms regulating myocardial regeneration. By contrast, adult mammals have an extremely limited capacity for cardiac regeneration, contributing to mortality and morbidity from cardiac diseases such as myocardial infarction and heart failure. However, the viewpoint of the mammalian heart as a postmitotic organ was recently revised based on findings that the mammalian heart contains multiple undifferentiated cell types with cardiogenic potential as well as a robust regenerative capacity during a short period early in life. Although it occurs at an extremely low level, continuous cardiomyocyte turnover has been detected in adult mouse and human hearts, which could potentially be enhanced to restore lost myocardium in damaged human hearts. This review summarizes and discusses recent advances in the understanding of endogenous mechanisms of cardiac regeneration. PMID:27572127

  19. Endogenous opiates and behavior: 2004.

    PubMed

    Bodnar, Richard J; Klein, Gad E

    2005-12-01

    This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses. PMID:16039752

  20. Endogenous opiates and behavior: 2013.

    PubMed

    Bodnar, Richard J

    2014-12-01

    This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses. PMID:25263178

  1. Endogenous opiates and behavior: 2007.

    PubMed

    Bodnar, Richard J

    2008-12-01

    This paper is the thirtieth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2007 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses. PMID:18851999

  2. [Zinc and gastrointestinal disorders].

    PubMed

    Higashimura, Yasuki; Takagi, Tomohisa; Naito, Yuji

    2016-07-01

    Zinc, an essential trace element, affects immune responses, skin metabolism, hormone composition, and some sensory function, so that the deficiency presents various symptoms such as immunodeficiency and taste obstacle. Further, the zinc deficiency also considers as a risk of various diseases. Recent reports demonstrated that -20% of the Japanese population was marginally zinc deficiency, and over 25% of the global population is at high risk of zinc deficiency. In gastrointestinal disorders, zinc plays an important role in the healing of mucosal and epithelial damage. In fact, polaprezinc, a chelate compound of zinc and L-carnosine, has been used for the treatment of gastric ulcer and gastritis. We describe here the therapeutic effect of zinc on gastrointestinal disorders. PMID:27455800

  3. Cadmium and zinc relationships.

    PubMed Central

    Elinder, C G; Piscator, M

    1978-01-01

    Cadmium and zinc concentrations in kidney and liver have been measured under different exposure situations in different species including man. The results show that zinc increases almost equimolarly with cadmium in kidney after long-term low-level exposure to cadmium, e.g., in man, horse, pig, and lamb. In contrast, the increase of zinc follows that of cadmium to only a limited extent, e.g., in guinea pig, rabbit, rat, mouse, and chicks. In liver, the cadmium--zinc relationship seems to be reversed in such a way that zinc increases with cadmium more markedly in laboratory animals than in higher mammals. These differences between cadmium and zinc relationships in humans and large farm animals and those in commonly used laboratory animals must be considered carefully before experimental data on cadmium and zinc relationships in laboratory animals can be extrapolated to humans. PMID:720298

  4. Soybean extracts increase cell surface ZIP4 abundance and cellular zinc levels: a potential novel strategy to enhance zinc absorption by ZIP4 targeting.

    PubMed

    Hashimoto, Ayako; Ohkura, Katsuma; Takahashi, Masakazu; Kizu, Kumiko; Narita, Hiroshi; Enomoto, Shuichi; Miyamae, Yusaku; Masuda, Seiji; Nagao, Masaya; Irie, Kazuhiro; Ohigashi, Hajime; Andrews, Glen K; Kambe, Taiho

    2015-12-01

    Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin-Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans. PMID:26385990

  5. Respiratory response of guinea pigs to zinc oxide fume

    SciTech Connect

    Amdur, M.O.; McCarthy, J.F.; Gill, M.W.

    1983-02-01

    Zinc has been found enriched in the fine particle fraction of atmospheric aerosols and in the surface layer of fly ash. Experimental combustion studies of coal have demonstrated that zinc is vaporized and recondensed into the submicrometer fraction of the combustion aerosols. This size fraction may contain as much as 1.5% zinc when a coal of high zinc content (Illinois No. 6) is used. Zinc sulfate and zinc ammonium sulfate are among the sulfates with demonstrable irritant potency. Zinc oxide was thus chosen as the initial aerosol for studies of biological and chemical interaction of high temperature generated submicrometer metal oxides with sulfur dioxide. This paper reports the respiratory response of guinea pigs to short term exposure to freshly formed zinc oxide fume. These studies of zinc oxide alone have relevance to industrial exposure. The recommended TLV for zinc oxide is 5 mg/m/sup 3/ and the recommended STEL is 10 mg/m/sup 3/. Concentrations used in our studies were below these recommended levels.

  6. ADAPTATION IN ZINC ABSORPTION FROM WHOLE DIETS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited evidence suggests that humans increase zinc (Zn) absorption in response to low Zn intake. Aim: To assess human Zn absorption from whole diets varying in Zn content, and short-term adaptation to meet apparent Zn requirements. Method: Using 65Zn and whole body counting, Zn absorption by 83 hea...

  7. Improved zinc electrode and rechargeable zinc-air battery

    SciTech Connect

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  8. Contribution by synaptic zinc to the gender-disparate plaque formation in human Swedish mutant APP transgenic mice

    PubMed Central

    Lee, Joo-Yong; Cole, Toby B.; Palmiter, Richard D.; Suh, Sang Won; Koh, Jae-Young

    2002-01-01

    Endogenous metals may contribute to the accumulation of amyloid plaques in Alzheimer's disease. To specifically examine the role of synaptic zinc in the plaque accumulation, Tg2576 (also called APP2576) transgenic mice (hAPP+) expressing cerebral amyloid plaque pathology were crossed with mice lacking zinc transporter 3 (ZnT3−/−), which is required for zinc transport into synaptic vesicles. With aging, female hAPP+:ZnT3+/+ mice manifested higher levels of synaptic zinc, insoluble amyloid β, and plaques than males; these sex differences disappeared in hAPP+:ZnT3−/− mice. Both sexes of hAPP+:ZnT3−/− mice had markedly reduced plaque load and less insoluble amyloid β compared with hAPP+:ZnT3+/+ mice. Hence, of endogenous metals, synaptic zinc contributes predominantly to amyloid deposition in hAPP+ mice. PMID:12032347

  9. Zinc bioavailability in rats fed a plant-based diet: a study of fermentation and zinc supplementation

    PubMed Central

    Lazarte, Claudia E.; Vargas, Mirian; Granfeldt, Yvonne

    2015-01-01

    Background Zinc deficiency is a significant problem, in developing countries and in vegetarians, which can be caused by plant-based diets. Thus, dietary strategies, such as fermentation, to improve zinc bioavailability of diets should be investigated. Objective To improve zinc bioavailability in a plant-based diet by the inclusion of fermented food. Design Cassava tubers were fermented and made to replace the unfermented cassava in a basal plant-based diet, and compared with plant-based diets with and without zinc supplement. The zinc bioavailability of the diets was evaluated in Wistar rats that were fed these diets for 28 days. The evaluation was for zinc apparent absorption (ZnAA), serum zinc levels, and zinc deposits in liver and femur; in addition, the feed efficiency ratio (FER) of the diets and femur weight (FW) of the rats were evaluated. Results During the cassava fermentation, lactic acid increased and pH decreased (from 6.8 to 3.9), which is favorable for native phytase activity, resulting in a 90.2% reduction of phytate content in cassava. The diet containing fermented cassava showed significantly higher levels of ZnAA, FER, and FW (p<0.001). Moreover, the zinc levels in serum and femur were significantly higher (p<0.001) compared with the results of the diet with unfermented cassava. The results clearly show a higher zinc bioavailability in the diet containing fermented cassava and are comparable with the results obtained with the plant-based diet with zinc supplement. Conclusions In conclusion, the fermentation of cassava reduces the phytate content. The diet containing the fermented cassava represents a better nutritional alternative than the diet with unfermented cassava and is comparable with the zinc-supplemented diets. PMID:26626410

  10. Endogenous Methanol Regulates Mammalian Gene Activity

    PubMed Central

    Komarova, Tatiana V.; Petrunia, Igor V.; Shindyapina, Anastasia V.; Silachev, Denis N.; Sheshukova, Ekaterina V.; Kiryanov, Gleb I.; Dorokhov, Yuri L.

    2014-01-01

    We recently showed that methanol emitted by wounded plants might function as a signaling molecule for plant-to-plant and plant-to-animal communications. In mammals, methanol is considered a poison because the enzyme alcohol dehydrogenase (ADH) converts methanol into toxic formaldehyde. However, the detection of methanol in the blood and exhaled air of healthy volunteers suggests that methanol may be a chemical with specific functions rather than a metabolic waste product. Using a genome-wide analysis of the mouse brain, we demonstrated that an increase in blood methanol concentration led to a change in the accumulation of mRNAs from genes primarily involved in detoxification processes and regulation of the alcohol/aldehyde dehydrogenases gene cluster. To test the role of ADH in the maintenance of low methanol concentration in the plasma, we used the specific ADH inhibitor 4-methylpyrazole (4-MP) and showed that intraperitoneal administration of 4-MP resulted in a significant increase in the plasma methanol, ethanol and formaldehyde concentrations. Removal of the intestine significantly decreased the rate of methanol addition to the plasma and suggested that the gut flora may be involved in the endogenous production of methanol. ADH in the liver was identified as the main enzyme for metabolizing methanol because an increase in the methanol and ethanol contents in the liver homogenate was observed after 4-MP administration into the portal vein. Liver mRNA quantification showed changes in the accumulation of mRNAs from genes involved in cell signalling and detoxification processes. We hypothesized that endogenous methanol acts as a regulator of homeostasis by controlling the mRNA synthesis. PMID:24587296

  11. Evaluation of the alkaline electrolysis of zinc

    SciTech Connect

    Meisenhelder, J.H.; Brown, A.P.; Loutfy, R.O.; Yao, N.P.

    1981-05-01

    The alkaline leach and electrolysis process for zinc production is compared to the conventional acid-sulfate process in terms of both energy saving and technical merit. In addition, the potential for industrial application of the alkaline process is discussed on the basis of present market conditions, possible future zinc market scenarios, and the probability of increased secondary zinc recovery. In primary zinc production, the energy-saving potential for the alkaline process was estimated to be greater than 10%, even when significantly larger electrolysis current densities than those required for the sulfate process are used. The principal technical advantages of the alkaline process are that it can handle low-grade, high-iron-content or oxidized ores (like most of those found in the US) in a more cost- and energy-efficient manner than can the sulfate process. Additionally, in the electrowinning operation, the alkaline process should be technically superior because a dendritic or sponge deposit is formed that is amenable to automated collection without interruption of the electrolysis. Also, use of the higher current densities would result in significant capital cost reductions. Alkaline-based electrolytic recovery processes were considered for the recycling of zinc from smelter baghouse dusts and from the potential source of nickel/zinc electric-vehicle batteries. In all comparisons, an alkaline process was shown to be technically superior and, particularly for the baghouse dusts, energetically and economically superior to alternatively proposed recovery methods based on sulfate electrolysis. It is concluded that the alkaline zinc method is an important alternative technology to the conventional acid zinc process. (WHK)

  12. Zinc electrode and rechargeable zinc-air battery

    SciTech Connect

    Ross, P.N. Jr.

    1989-06-27

    This patent describes an improved zinc electrode for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed.

  13. Zinc Extraction from Zinc Plants Residue Using Selective Alkaline Leaching and Electrowinning

    NASA Astrophysics Data System (ADS)

    Ashtari, Pedram; Pourghahramani, Parviz

    2015-10-01

    Annually, a great amount of zinc plants residue is produced in Iran. One of them is hot filter cake (known as HFC) which can be used as a secondary resource of zinc, cobalt and manganese. Unfortunately, despite its heavy metal content, the HFC is not treated. For the first time, zinc was selectively leached from HFC employing alkaline leaching. Secondly, leaching was optimized to achieve maximum recovery using this method. Effects of factors like NaOH concentration (C = 3, 5, 7 and 9 M), temperature (T = 50, 70, 90 and 105 °C), solid/liquid ratio (weight/volume, S/L = 1/10 and 1/5 W/V) and stirring speed (R = 500 and 800 rpm) were studied on HFC leaching. L16 orthogonal array (OA, two factors in four levels and two factors in two levels) was applied to determine the optimum condition and the most significant factor affecting the overall zinc extraction. As a result, maximum zinc extraction was 83.4 %. Afterwards, a rough test was conducted for zinc electrowinning from alkaline solution according to the common condition available in literature by which pure zinc powder (99.96 %) was successfully obtained.

  14. Zinc in Entamoeba invadens.

    NASA Technical Reports Server (NTRS)

    Morgan, R. S.; Sattilaro, R. F.

    1972-01-01

    Atomic absorption spectroscopy, electron microprobe analysis, and dithizone staining of trophozoites and cysts of Entamoeba invadens demonstrate that these cells have a high concentration of zinc (approximately one picogram per cell or 1% of their dry weight). In the cysts of this organism, the zinc is confined to the chromatoid bodies, which previous work has shown to contain crystals of ribosomes. The chemical state and function of this zinc are unknown.

  15. Vegetarian diets across the lifecycle: impact on zinc intake and status.

    PubMed

    Foster, Meika; Samman, Samir

    2015-01-01

    Optimal zinc status is an important consideration when evaluating the nutritional adequacy of vegetarian diets. In the absence of animal tissue sources of zinc and with increased intake of inhibitors of zinc absorption, phytic acid in particular, the bioavailability of zinc is thought to be lower from vegetarian as compared to omnivorous diets. The aim of this chapter is to review the research that examines the effects of vegetarian compared to omnivorous diets on zinc intake and zinc status in the elderly, adults, children, pregnancy, and lactation. A narrative review of the published literature was undertaken, focusing on observational studies in humans that reported zinc intake and biomarkers of zinc status at various stages of the life cycle. Compared to their respective nonvegetarian control groups, adult male and female vegetarians have lower dietary zinc intakes and serum zinc concentrations. However in the elderly, children, and in women during pregnancy and lactation, there is insufficient evidence to determine whether zinc intake and status are lower in vegetarians compared to omnivores. Inconsistencies in study findings reflect variations inherent in the definition of vegetarian diets, and in many instances compromised statistical power due to a small sample size. Improved methods for the assessment of zinc status are required to determine whether homeostatic responses are sufficient to maintain an adequate zinc status in vegetarians, particularly during times of increased requirement. Appropriate dietary advice to increase the zinc content and bioavailability of vegetarian diets throughout the life cycle is prudent. PMID:25624036

  16. Zinc and Chlamydia trachomatis

    SciTech Connect

    Sugarman, B.; Epps, L.R.

    1985-07-01

    Zinc was noted to have significant effects upon the infection of McCoy cells by each of two strains of Chlamydia trachomatis. With a high or low Chlamydia inoculant, the number of infected cells increased up to 200% utilizing supplemental zinc (up to 1 x 10/sup -4/ M) in the inoculation media compared with standard Chlamydia cultivation media (8 x 10/sup -6/ M zinc). Ferric chloride and calcium chloride did not effect any such changes. Higher concentrations of zinc, after 2 hr of incubation with Chlamydia, significantly decreased the number of inclusions. This direct effect of zinc on the Chlamydia remained constant after further repassage of the Chlamydia without supplemental zinc, suggesting a lethal effect of the zinc. Supplemental zinc (up to 10/sup -4/ M) may prove to be a useful addition to inoculation media to increase the yield of culturing for Chlamydia trachomatis. Similarly, topical or oral zinc preparations used by people may alter their susceptibility to Chamydia trachomatis infections.

  17. Zinc: An Essential Micronutrient

    PubMed Central

    SAPER, ROBERT B.; RASH, REBECCA

    2009-01-01

    Zinc is an essential micronutrient for human metabolism that catalyzes more than 100 enzymes, facilitates protein folding, and helps regulate gene expression. Patients with malnutrition, alcoholism, inflammatory bowel disease, and malabsorption syndromes are at an increased risk of zinc deficiency. Symptoms of zinc deficiency are nonspecific, including growth retardation, diarrhea, alopecia, glossitis, nail dystrophy, decreased immunity, and hypogonadism in males. In developing countries, zinc supplementation may be effective for the prevention of upper respiratory infection and diarrhea, and as an adjunct treatment for diarrhea in malnourished children. Zinc in combination with antioxidants may be modestly effective in slowing the progression of intermediate and advanced age-related macular degeneration. Zinc is an effective treatment for Wilson disease. Current data do not support zinc supplementation as effective for upper respiratory infection, wound healing, or human immunodeficiency virus. Zinc is well tolerated at recommended dosages. Adverse effects of long-term high-dose zinc use include suppressed immunity, decreased high-density lipoprotein cholesterol levels, anemia, copper deficiency, and possible genitourinary complications. PMID:20141096

  18. Endogenous endostatin inhibits choroidal neovascularization.

    PubMed

    Marneros, Alexander G; She, Haicheng; Zambarakji, Hadi; Hashizume, Hiroya; Connolly, Edward J; Kim, Ivana; Gragoudas, Evangelos S; Miller, Joan W; Olsen, Bjorn R

    2007-12-01

    Endostatin, a fragment of the basement membrane component collagen XVIII, exhibits antiangiogenic properties in vitro and in vivo when high doses are administered. It is not known whether endogenous endostatin at physiological levels has a protective role as an inhibitor of pathological angiogenesis, such as choroidal neovascularization (CNV) in age-related macular degeneration. Using a laser injury model, we induced CNV in mice lacking collagen XVIII/endostatin and in control mice. CNV lesions in mutant mice were approximately 3-fold larger than in control mice and showed increased vascular leakage. These differences were independent of age-related changes at the choroid-retina interface. Ultrastructural analysis of the choroidal vasculature in mutant mice excluded morphological vascular abnormalities as a cause for the larger CNV lesions. When recombinant endostatin was administered to collagen XVIII/endostatin-deficient mice, CNV lesions were similar to those seen in control mice. In control mice treated with recombinant endostatin, CNV lesions were almost undetectable. These findings demonstrate that endogenous endostatin is an inhibitor of induced angiogenesis and that administration of endostatin potently inhibits CNV growth and vascular leakage. Endostatin may have a regulatory role in the pathogenesis of CNV and could be used therapeutically to inhibit growth and leakage of CNV lesions. PMID:17526870

  19. Endogenous Opiates and Behavior: 2006

    PubMed Central

    Bodnar, Richard J.

    2009-01-01

    This paper is the twenty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning thirty years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:17949854

  20. Endogenous opiates and behavior: 2012.

    PubMed

    Bodnar, Richard J

    2013-12-01

    This paper is the thirty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2012 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:24126281

  1. Endogenous opiates and behavior: 2009.

    PubMed

    Bodnar, Richard J

    2010-12-01

    This paper is the 32nd consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2009 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:20875476

  2. Endogenous opiates and behavior: 2005.

    PubMed

    Bodnar, Richard J; Klein, Gad E

    2006-12-01

    This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17). PMID:16973239

  3. Endogenous opiates and behavior: 2008.

    PubMed

    Bodnar, Richard J

    2009-12-01

    This paper is the 31st consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2008 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:19793543

  4. Endogenous opiates and behavior: 2010.

    PubMed

    Bodnar, Richard J

    2011-12-01

    This paper is the thirty-third consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2010 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17). PMID:21983105

  5. Endogenous opiates and behavior: 2006.

    PubMed

    Bodnar, Richard J

    2007-12-01

    This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:17949854

  6. Endogenous opiates and behavior: 2011.

    PubMed

    Bodnar, Richard J

    2012-12-01

    This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17). PMID:23041439

  7. Endogenous opiates and behavior: 2002.

    PubMed

    Bodnar, Richard J; Hadjimarkou, Maria M

    2003-08-01

    This paper is the twenty-fifth consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2002 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:14612197

  8. Endogenous opiates and behavior: 2003.

    PubMed

    Bodnar, Richard J; Klein, Gad E

    2004-12-01

    This paper is the 26th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2003 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:15572211

  9. Evaluation of the endogenous glucocorticoid hypothesis of denervation atrophy

    NASA Technical Reports Server (NTRS)

    Konagaya, Masaaki; Konagaya, Yoko; Max, Stephen R.

    1988-01-01

    The effects are studied of the oral administration of RU38486, a potent selective glucocorticoid antagonist, on muscle weight, non-collagen protein content, and selected enzyme activities (choline acetyltransferase, glucose 6-phosphate dehydrogenase, and glutamine synthetase) following denervation of rat skeletal muscle. Neither decreases in muscle weight, protein content, and choline acetyltransferase activity, nor increases in the activities of glucose 6-phosphate dehydrogernase and glutamine synthetase were affected by RU38486. These data do not support the hypothesis that denervation atrophy results from enhanced sensitivity of muscle to endogenous glucocorticoids.

  10. Improving access to endogenous DNA in ancient bones and teeth

    PubMed Central

    Damgaard, Peter B.; Margaryan, Ashot; Schroeder, Hannes; Orlando, Ludovic; Willerslev, Eske; Allentoft, Morten E.

    2015-01-01

    Poor DNA preservation is the most limiting factor in ancient genomic research. In the majority of ancient bones and teeth, endogenous DNA molecules represent a minor fraction of the whole DNA extract, rendering shot-gun sequencing inefficient for obtaining genomic data. Based on ancient human bone samples from temperate and tropical environments, we show that an EDTA-based enzymatic ‘pre-digestion’ of powdered bone increases the proportion of endogenous DNA several fold. By performing the pre-digestion step between 30 min and 6 hours on five bones, we observe an asymptotic increase in endogenous DNA content, with a 2.7-fold average increase reached at 1 hour. We repeat the experiment using a brief pre-digestion (15 or 30 mins) on 21 ancient bones and teeth from a variety of archaeological contexts and observe an improvement in 16 of these. We here advocate the implementation of a brief pre-digestion step as a standard procedure in ancient DNA extractions. Finally, we demonstrate on 14 ancient teeth that by targeting the outer layer of the roots we obtain up to 14 times more endogenous DNA than when using the inner dentine. Our presented methods are likely to increase the proportion of ancient samples that are suitable for genome-scale characterization. PMID:26081994

  11. Zinc deficiency and eating disorders.

    PubMed

    Humphries, L; Vivian, B; Stuart, M; McClain, C J

    1989-12-01

    Decreased food intake, a cyclic pattern of eating, and weight loss are major manifestations of zinc deficiency. In this study, zinc status was evaluated in 62 patients with bulimia and 24 patients with anorexia nervosa. Forty percent of patients with bulimia and 54% of those with anorexia nervosa had biochemical evidence of zinc deficiency. The authors suggest that for a variety of reasons, such as lower dietary intake of zinc, impaired zinc absorption, vomiting, diarrhea, and binging on low-zinc foods, patients with eating disorders may develop zinc deficiency. This acquired zinc deficiency could then add to the chronicity of altered eating behavior in those patients. PMID:2600063

  12. Zinc Levels in Seminal Fluid in Infertile Males and its Relation with Serum Free Testosterone

    PubMed Central

    Chaudhari, Ajay Rajeshwar

    2016-01-01

    Introduction The role of zinc is critical to reproduction potential. Seminal zinc is thought to be derived almost exclusively from prostatic secretions. Sperm motility is significantly influenced by zinc. Zinc deficiency has been linked with male sterility and subfertility. Aim To assess the influence of seminal plasma zinc on seminogram characteristics and whether endogenous testosterone affects the seminal levels of zinc. Materials and Methods The semen samples were obtained from 150 male partners of infertile couples who attended the Reproductive Biology Unit of the Department of Physiology, within the age 21-50 years and semen samples were analysed for the routine seminogram parameters. All the subjects were classified into two main groups, A- the subjects with normal ejaculates (n=62) and B- the subjects with abnormal ejaculates, who were further sub divided into the following groups: i) Asthenoteratozoospermics (n=43); ii) Oligoasthenoteratozoospermics (n=24); and iii) Azoospermics (n=21). The seminal plasma zinc was measured spectrophotometrically. The sample for serum free testosterone was sent to Thyrocare laboratory. Results The seminal plasma zinc was found to be significantly lower in the abnormal ejaculates than in the normal ejaculates. A statistically significant positive correlation was observed between the seminal plasma zinc and serum free testosterone (p<0.05, r=0.449). Statistically significant correlation was also found between seminal plasma zinc and all the seminogram parameters such as the sperm concentration, sperm motility and sperm morphology (p<0.05, r= 0.86, 0.87 and 0.86 respectively). Conclusion Low seminal plasma zinc might be a significant causative factor in impairing sperm functions and its dependence on endogenous free testosterone, is observed from a positive correlation between the two. PMID:27437207

  13. Preparation of zinc orthotitanate

    NASA Technical Reports Server (NTRS)

    Gates, D. W.; Gilligan, J. E.; Harada, Y.; Logan, W. R.

    1977-01-01

    Use of decomposable precursors to enhance zinc oxide-titanium dioxide reaction and rapid fixing results in rapid preparation of zinc orthotitanate powder pigment. Preparation process allows production under less stringent conditions. Elimination of powder grinding results in purer that is less susceptible to color degradation.

  14. Zinc Inhibits Hedgehog Autoprocessing

    PubMed Central

    Xie, Jian; Owen, Timothy; Xia, Ke; Singh, Ajay Vikram; Tou, Emiley; Li, Lingyun; Arduini, Brigitte; Li, Hongmin; Wan, Leo Q.; Callahan, Brian; Wang, Chunyu

    2015-01-01

    Zinc is an essential trace element with wide-ranging biological functions, whereas the Hedgehog (Hh) signaling pathway plays crucial roles in both development and disease. Here we show that there is a mechanistic link between zinc and Hh signaling. The upstream activator of Hh signaling, the Hh ligand, originates from Hh autoprocessing, which converts the Hh precursor protein to the Hh ligand. In an in vitro Hh autoprocessing assay we show that zinc inhibits Hh autoprocessing with a Ki of 2 μm. We then demonstrate that zinc inhibits Hh autoprocessing in a cellular environment with experiments in primary rat astrocyte culture. Solution NMR reveals that zinc binds the active site residues of the Hh autoprocessing domain to inhibit autoprocessing, and isothermal titration calorimetry provided the thermodynamics of the binding. In normal physiology, zinc likely acts as a negative regulator of Hh autoprocessing and inhibits the generation of Hh ligand and Hh signaling. In many diseases, zinc deficiency and elevated level of Hh ligand co-exist, including prostate cancer, lung cancer, ovarian cancer, and autism. Our data suggest a causal relationship between zinc deficiency and the overproduction of Hh ligand. PMID:25787080

  15. Endogenous opiates and behavior: 2001.

    PubMed

    Bodnar, Richard J; Hadjimarkou, Maria M

    2002-12-01

    This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17). PMID:12535711

  16. Exploring zinc coordination in novel zinc battery electrolytes.

    PubMed

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2014-06-14

    The coordination of zinc ions by tetraglyme has been investigated here to support the development of novel electrolytes for rechargeable zinc batteries. Zn(2+) reduction is electrochemically reversible from tetraglyme. The spectroscopic data, molar conductivity and thermal behavior as a function of zinc composition, between mole ratios [80 : 20] and [50 : 50] [tetraglyme : zinc chloride], all suggest that strong interactions take place between chloro-zinc complexes and tetraglyme. Varying the concentration of zinc chloride produces a range of zinc-chloro species (ZnClx)(2-x) in solution, which hinder full interaction between the zinc ion and tetraglyme. Both the [70 : 30] and [50 : 50] mixtures are promising electrolyte candidates for reversible zinc batteries, such as the zinc-air device. PMID:24760367

  17. Constitutive expression of the ZmZIP7 in Arabidopsis alters metal homeostasis and increases Fe and Zn content.

    PubMed

    Li, Suzhen; Zhou, Xiaojin; Zhao, Yongfeng; Li, Hongbo; Liu, Yuanfeng; Zhu, Liying; Guo, Jinjie; Huang, Yaqun; Yang, Wenzhu; Fan, Yunliu; Chen, Jingtang; Chen, Rumei

    2016-09-01

    Iron (Fe) and zinc (Zn) are important micronutrients for plant growth and development. Zinc-regulated transporters and the iron-regulated transporter-like protein (ZIP) are necessary for the homeostatic regulation of these metal micronutrients. In this study, the physiological function of ZmZIP7 which encodes a ZIP family transporter was characterized. We detected the expression profiles of ZmZIP7 in maize, and found that the accumulation of ZmZIP7 in root, stem, leaf, and seed was relatively higher than tassel and young ear. ZmZIP7 overexpression transgenic Arabidopsis lines were generated and the metal contents in transgenic and wild-type (WT) plants were examined using inductively coupled plasma atomic emission spectroscopy (ICP-OES) and Zinpyr-1 staining. Fe and Zn concentrations were elevated in the roots and shoots of ZmZIP7-overexpressing plants, while only Fe content was elevated in the seeds. We also analyzed the expression profiles of endogenous genes associated with metal homeostasis. Both endogenic Fe-deficiency inducible genes and the genes responsible for Zn and Fe transport and storage were stimulated in ZmZIP7 transgenic plants. In conclusion, ZmZIP7 encodes a functional Zn and Fe transporter, and ectopic overexpression of ZmZIP7 in Arabidopsis stimulate endogenous Fe and Zn uptake mechanisms, thereby facilitating both metal uptake and homeostasis. Our results contribute to improved understanding of ZIP family transporter functions and suggest that ZmZIP7 could be used to enhance Fe levels in grains. PMID:27135812

  18. Resistant starch does not affect zinc homeostasis in rural Malawian children☆,☆☆

    PubMed Central

    Thakwalakwa, Chrissie; Ordiz, M. Isabel; Maleta, Ken; Westcott, Jamie; Ryan, Kelsey; Hambidge, K. Michael; Miller, Leland V.; Young, Graeme; Mortimer, Elissa; Manary, Mark J.; Krebs, Nancy F.

    2015-01-01

    Objective This study tested the hypothesis that Malawian children at risk for zinc deficiency will have reduced endogenous fecal zinc (EFZ) and increased net absorbed zinc (NAZ) following the addition of high amylose maize resistant starch (RS) to their diet. Methods This was a small controlled clinical trial to determine the effects of added dietary RS on zinc homeostasis among 17 stunted children, aged 3–5 years consuming a plant-based diet and at risk for perturbed zinc homeostasis. Dual zinc stable isotope studies were performed before and after 28 d of intervention with RS, so that each child served as their own control. The RS was incorporated into fried wheat flour dough and given under direct observation twice daily for 28 d. Changes in zinc homeostatic measures were compared using paired Student's t-tests and linear regression analysis. Results Children had a mean height-for-age Z-score of −3.3, and consumed animal source foods ≤twice per month. Their habitual diet contained a phytate:zinc molar ratio of 34:1. Children avidly consumed the RS without complaints. EFZ was 0.8±0.4 mg/d (mean±SD) both before and after the intervention. Fractional absorption of zinc was 0.38±0.08 and 0.35±0.06 before and after the RS intervention respectively. NAZ was 1.1±0.5 and 0.6±0.7 before and after the RS intervention. This reduction of NAZ corresponded with diminished dietary zinc intake on the study day following intervention with RS. Regression analysis indicated no change in zinc absorption relative to dietary intake as a result of the RS intervention. Conclusion Consumption of RS did not improve zinc homeostasis in rural African children without zinc deficiency. RS was well tolerated in this setting. PMID:25744509

  19. Improve the flame retardancy of cellulose fibers by grafting zinc ion.

    PubMed

    Zhang, KeKe; Zong, Lu; Tan, Yeqiang; Ji, Quan; Yun, Weicai; Shi, Ran; Xia, Yanzhi

    2016-01-20

    Zinc ion as the only flame retardant of cellulose fibers was successfully grafted onto cellulose fibers. Grafting maleic anhydride onto cellulose fibers via homogeneous acylation reaction between N,N-dimethyl formamide (DMF) as the first step. Then, graft zinc ion onto the formed cellulose fibers was conducted with zinc carbonate. The resulting copolymers were characterized by FTIR. Flame retardancy and thermal degradation of zinc-ion-modified cellulose fibers (cellulose-Zn fibers) was investigated by limiting oxygen index (LOI), cone calorimeter (CONE), XRD, TG and SEM. Zinc ion could effectively improve flame retardancy and thermal degradation when its content increases up to 4.96 wt%. PMID:26572337

  20. Interstitial zinc clusters in zinc oxide

    NASA Astrophysics Data System (ADS)

    Gluba, M. A.; Nickel, N. H.; Karpensky, N.

    2013-12-01

    Doped zinc oxide (ZnO) exhibits anomalous Raman modes in the range of 270 to 870 cm-1. Commonly, the resonance at 275 cm-1 is attributed to the local vibration of Zn atoms in the vicinity of extrinsic dopants. We revisit this assignment by investigating the influence of isotopically purified zinc oxide thin films on the frequency of the vibrational mode around 275 cm-1. For this purpose, undoped and nitrogen-doped ZnO thin-films with Zn isotope compositions of natural Zn, 64Zn, 68Zn, and a 1:1 mixture of 64Zn and 68Zn were grown by pulsed laser deposition. The isotopic shift and the line shape of the Raman resonance around 275 cm-1 are analyzed in terms of three different microscopic models, which involve the vibration of (i) interstitial zinc atoms bound to extrinsic defects, (ii) interstitial diatomic Zn molecules, and (iii) interstitial zinc clusters. The energy diagram of interstitial Zn-Zn bonds in a ZnO matrix is derived from density functional theory calculations. The interstitial Zn-Zn bond is stabilized by transferring electrons from the antibonding orbital into the ZnO conduction band. This mechanism facilitates the formation of interstitial Zn clusters and fosters the common n-type doping asymmetry of ZnO.

  1. Designing Hydrolytic Zinc Metalloenzymes

    PubMed Central

    2015-01-01

    Zinc is an essential element required for the function of more than 300 enzymes spanning all classes. Despite years of dedicated study, questions regarding the connections between primary and secondary metal ligands and protein structure and function remain unanswered, despite numerous mechanistic, structural, biochemical, and synthetic model studies. Protein design is a powerful strategy for reproducing native metal sites that may be applied to answering some of these questions and subsequently generating novel zinc enzymes. From examination of the earliest design studies introducing simple Zn(II)-binding sites into de novo and natural protein scaffolds to current studies involving the preparation of efficient hydrolytic zinc sites, it is increasingly likely that protein design will achieve reaction rates previously thought possible only for native enzymes. This Current Topic will review the design and redesign of Zn(II)-binding sites in de novo-designed proteins and native protein scaffolds toward the preparation of catalytic hydrolytic sites. After discussing the preparation of Zn(II)-binding sites in various scaffolds, we will describe relevant examples for reengineering existing zinc sites to generate new or altered catalytic activities. Then, we will describe our work on the preparation of a de novo-designed hydrolytic zinc site in detail and present comparisons to related designed zinc sites. Collectively, these studies demonstrate the significant progress being made toward building zinc metalloenzymes from the bottom up. PMID:24506795

  2. Endogenous Peer Effects: Fact or Fiction?

    ERIC Educational Resources Information Center

    Yeung, Ryan; Nguyen-Hoang, Phuong

    2016-01-01

    The authors examine endogenous peer effects, which occur when a student's behavior or outcome is a function of the behavior or outcome of his or her peer group. Endogenous peer effects have important implications for educational policies such as busing, school choice and tracking. In this study, the authors quantitatively review the literature on…

  3. Endogenous timing factors in bird migration

    NASA Technical Reports Server (NTRS)

    Gwinner, E. G.

    1972-01-01

    Several species of warbler birds were observed in an effort to determine what initiates and terminates migration. Environmental and endogenous timing mechanisms were analyzed. The results indicate that endogenous stimuli are dominant factors for bird migration especially for long distances. It was concluded that environmental factors act as an assist mechanism.

  4. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  5. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  6. Dietary Zinc Deficiency Exaggerates Ethanol-Induced Liver Injury in Mice: Involvement of Intrahepatic and Extrahepatic Factors

    PubMed Central

    Sun, Xinguo; Song, Zhenyuan; McClain, Craig J.; Zhou, Zhanxiang

    2013-01-01

    Clinical studies have demonstrated that alcoholics have a lower dietary zinc intake compared to health controls. The present study was undertaken to determine the interaction between dietary zinc deficiency and ethanol consumption in the pathogenesis of alcoholic liver disease. C57BL/6N mice were subjected to 8-week feeding of 4 experimental liquid diets: (1) zinc adequate diet, (2) zinc adequate diet plus ethanol, (3) zinc deficient diet, and (4) zinc deficient diet plus ethanol. Ethanol exposure with adequate dietary zinc resulted in liver damage as indicated by elevated plasma alanine aminotransferase level and increased hepatic lipid accumulation and inflammatory cell infiltration. Dietary zinc deficiency alone increased hepatic lipid contents, but did not induce hepatic inflammation. Dietary zinc deficiency showed synergistic effects on ethanol-induced liver damage. Dietary zinc deficiency exaggerated ethanol effects on hepatic genes related to lipid metabolism and inflammatory response. Dietary zinc deficiency worsened ethanol-induced imbalance between hepatic pro-oxidant and antioxidant enzymes and hepatic expression of cell death receptors. Dietary zinc deficiency exaggerated ethanol-induced reduction of plasma leptin, although it did not affect ethanol-induced reduction of white adipose tissue mass. Dietary zinc deficiency also deteriorated ethanol-induced gut permeability increase and plasma endotoxin elevation. These results demonstrate, for the first time, that dietary zinc deficiency is a risk factor in alcoholic liver disease, and multiple intrahepatic and extrahepatic factors may mediate the detrimental effects of zinc deficiency. PMID:24155903

  7. Sealed nickel-zinc battery

    SciTech Connect

    Gibbard, H. F.; Menard, C. J.; Murray Jr., R. C.; Putt, R. A.; Valentine, T. W.

    1985-11-12

    A sealed, rechargeable nickel-zinc cell includes a zinc electrode active mass essentially free of zinc metal when at full discharge, a carboxylated styrene-butadiene binder retaining the zinc electrode mixture in a coherent structure, a predetermined amount of cadmium being included in the zinc electrode mixture, a separator preferably comprising at least two layers of material free of any adhesive binding the layers together and a wicking layer positioned between the nickel positive electrode and the separator.

  8. Longitudinal changes in zinc transport kinetics, metallothionein, and zinc transporter expression in a blood-brain barrier model in response to a moderately excessive zinc environment$

    PubMed Central

    Gauthier, Nicole A.; Karki, Shakun; Olley, Bryony J.; Thomas, W. Kelly

    2008-01-01

    A blood-brain barrier (BBB) model composed of porcine brain capillary endothelial cells (BCEC) was exposed to a moderately excessive zinc environment (50 µmol Zn/L) in cell culture and longitudinal measurements were made of zinc transport kinetics, ZnT-1 (SLC30A1) expression, and changes in the protein concentration of metallothionein (MT), ZnT-1, ZnT-2 (SLC30A2), and Zip1 (SLC39A1). Zinc release by cells of the BBB model was significantly increased after 12–24 h of exposure, but decreased back to control levels after 48–96 h, as indicated by transport across the BBB from both the ablumenal (brain) and lumenal (blood) directions. Expression of ZnT-1, the zinc export protein, increased 169% within 12 h, but was no longer different from controls after 24 h. Likewise, ZnT-1 protein content increased transiently after 12 h of exposure but returned to control levels by 24 h. Capacity for zinc uptake and retention increased from both the lumenal and ablumenal directions within 12–24 h of exposure and remained elevated. MT and ZnT-2 were elevated within 12 h and remained elevated throughout the study. Zip1 was unchanged by the treatment. The BBB’s response to a moderately high zinc environment was dynamic and involved multiple mechanisms. The initial response was to increase the cell’s capacity to sequester zinc with additional MT and increase zinc export with the ZnT-1 protein. But, the longer term strategy involved increasing ZnT-2 transporters, presumably to sequester zinc into intracellular vesicles as a mechanism to protect the brain and maintain brain zinc homeostasis. PMID:18061429

  9. Hydrometallurgically recovering zinc from electric arc furnace dusts

    NASA Astrophysics Data System (ADS)

    Antrekowitsch, J.; Antrekowitsch, H.

    2001-12-01

    The increasing use of zinc-containing scrap for steel production has lead to a high zinc content in the electric arc furnace and converter flue dusts. The cost of disposing of this residue is high due to environmental restrictions. Various recycling processes have been developed for these dusts, but most never reached the pilot plant stage and many investigations were stopped because of metallurgical and economical inefficiencies. While pyrometallurgical methods have to deal with high energy consumption, low zinc yield, and valueless residues, hydrometallurgical processes could offer an economical recycling alternative. This paper describes hydrometallurgical methods for recovering zinc from steel industry dust. These methods can be integrated in the primary zinc-winning process or in galvanization. Investigations of sulfuric-acid leaching show high zinc solubility but also a high iron content in the final liquor. As a result, steps for purification are required that cannot be conducted economically. Alternatively, a NaOH leaching gives a satisfying zinc yield and a very low solubility for the iron that remains in the residue.

  10. Zinc in calcium phosphate mediates bone induction: in vitro and in vivo model.

    PubMed

    Luo, Xiaoman; Barbieri, Davide; Davison, Noel; Yan, Yonggang; de Bruijn, Joost D; Yuan, Huipin

    2014-01-01

    Zinc-containing tricalcium phosphate (Zn-TCP) was synthesized to investigate the role of zinc in osteoblastogenesis, osteoclastogenesis and in vivo bone induction in an ectopic implantation model. Zinc ions were readily released in the culture medium. Zn-TCP with the highest zinc content enhanced the alkaline phosphatase activity of human bone marrow stromal cells and tartrate-resistant acid phosphatase activity, as well as multinuclear giant cell formation of RAW264.7 monocyte/macrophages. RAW264.7 cultured with different dosages of zinc supplements in medium with or without zinc-free TCP showed that zinc could influence both the activity and the formation of multinuclear giant cells. After a 12-week implantation in the paraspinal muscle of canines, de novo bone formation and bone incidence increased with increasing zinc content in Zn-TCP - up to 52% bone in the free space. However, TCP without zinc induced no bone formation. Although the observed bone induction cannot be attributed to zinc release alone, these results indicate that zinc incorporated in TCP can modulate bone metabolism and render TCP osteoinductive, indicating to a novel way to enhance the functionality of this synthetic bone graft material. PMID:24140609

  11. Zinc recovery and waste sludge minimization from chromium passivation baths.

    PubMed

    Diban, Nazely; Mediavilla, Rosa; Urtiaga, Ane; Ortiz, Inmaculada

    2011-08-30

    This work reports the feasibility of applying emulsion pertraction technology (EPT) aiming at zinc recovery and waste minimization in the zinc electroplating processes that include Cr (III) passivation. The assessment consists of firstly the lifetime extension of the passivation baths by selective removal of the tramp ions zinc and iron, and secondly, the recovery of zinc for further reuse. Spent passivation baths from a local industry were tested, being the major metallic content: Cr(3+) 9000mg L(-1), Zn(2+) 12,000mg L(-1), Fe(3+) 100mg L(-1). Working in a Liqui-Cel hollow fiber membrane contactor and using the extractant bis(2,4,4-trimethylpentyl) phosphinic acid, reduction of zinc and iron concentrations below 60mg L(-1) and 2mg L(-1), respectively were obtained, while trivalent chromium, the active metal that generates the passivation layer, was retained in the baths. Zinc was selectively transferred to an acidic stripping phase that in the experimental time reached a concentration of 157,000mg L(-1). Zinc recovery by electrowinning from the acidic stripping phase without any pretreatment of the electrolyte solution provided a purity of 98.5%, matching the lower commercial zinc grade. As a result of the extension of the life time of the passivation bath, significant environmental advantages are derived such as minimization of the volume of hazardous wastes and savings in the consumption of raw materials. PMID:21704452

  12. [Effect of a zinc-enriched diet on the clinical and metabolic parameters in type 2 diabetic patients].

    PubMed

    Sharafetdinov, Kh Kh; Meshcheriakov, V A; Plotnikova, O A; Mazo, V K; Gmoshinskiĭ, I V; Aleshko-Ozhevskiĭ, Iu P; Sheviakova, L V; Makhova, N N

    2004-01-01

    It was investigated the influence of a diet with zinc supplementation on dynamic of glycaemia, lipid profile, blood pressure and weight in type 2 diabetic patients. Traditional hypocaloric diet was supplemented with zinc-spirulina (7.5 mg zinc per day). The results investigations indicated that a zinc-enriched diet has beneficial effects on basal and postprandial glycaemia, the content of cholesterol and triglycerides in serum in compared with a traditional hypocaloric diet. PMID:15460984

  13. Zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, Jr., Philip N.

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  14. Oral zinc therapy for zinc deficiency-related telogen effluvium.

    PubMed

    Karashima, Tadashi; Tsuruta, Daisuke; Hamada, Takahiro; Ono, Fumitake; Ishii, Norito; Abe, Toshifumi; Ohyama, Bungo; Nakama, Takekuni; Dainichi, Teruki; Hashimoto, Takashi

    2012-01-01

    Zinc is crucial for maintaining human body homeostasis and is one of the major components of hormones, signal molecules, and enzymes. Zinc deficiency is caused by insufficient uptake of zinc from food, or caused by malabsorption syndromes, increased gastrointestinal and urinary losses, and administration of various medications. In order to test whether oral zinc administration can successfully improve zinc deficiency-related alopecia, we treated five patients with zinc deficiency-related telogen effluvium with oral zinc administration in the form of polaprezinc (Promac®). In all patients, hair loss was cured or improved. The administration of zinc for zinc deficiency-related alopecia may recover appropriate activities of metalloenzymes, hedgehog signaling, and immunomodulation, all of which are required for normal control of hair growth cycle. PMID:22741940

  15. Zinc wired rebar

    SciTech Connect

    Zhang, X.G.; Hwang, J.

    1997-02-01

    A novel method for corrosion protection of rebar in concrete is reported wherein it is galvanically protected by attaching a zinc wire along its length. The self-corrosion and galvanic-corrosion loss of the zinc wire is dependent on the water/cement ratio, the size of the cathode, and the concrete cover thickness. The wire acts as a sacrificial anode when the rebar embedded in concrete is exposed to corrosive environments.

  16. Coordination dynamics of biological zinc “clusters” in metallothioneins and in the DNA-binding domain of the transcription factor Gal4

    PubMed Central

    Maret, Wolfgang; Larsen, Kjeld S.; Vallee, Bert L.

    1997-01-01

    The almost universal appreciation for the importance of zinc in metabolism has been offset by the considerable uncertainty regarding the proteins that store and distribute cellular zinc. We propose that some zinc proteins with so-called zinc cluster motifs have a central role in zinc distribution, since they exhibit the rather exquisite properties of binding zinc tightly while remaining remarkably reactive as zinc donors. We have used zinc isotope exchange both to probe the coordination dynamics of zinc clusters in metallothionein, the small protein that has the highest known zinc content, and to investigate the potential function of zinc clusters in cellular zinc distribution. When mixed and incubated, metallothionein isoproteins-1 and -2 rapidly exchange zinc, as demonstrated by fast chromatographic separation and radiometric analysis. Exchange kinetics exhibit two distinct phases (kfast ≃ 5000 min−1·M−1; kslow ≃ 200 min−1·M−1, pH 8.6, 25°C) that are thought to reflect exchange between the three-zinc clusters and between the four-zinc clusters, respectively. Moreover, we have observed and examined zinc exchange between metallothionein-2 and the Gal4 protein (k ≃ 800 min−1·M−1, pH 8.0, 25°C), which is a prototype of transcription factors with a two-zinc cluster. This reaction constitutes the first experimental example of intermolecular zinc exchange between heterologous proteins. Such kinetic reactivity distinguishes zinc in biological clusters from zinc in the coordination environment of zinc enzymes, where the metal does not exchange over several days with free zinc in solution. The molecular organization of these clusters allows zinc exchange to proceed through a ligand exchange mechanism, involving molecular contact between the reactants. PMID:9122177

  17. Zinc recovery from spent ZnO catalyst by carbon in the presence of calcium carbonate

    NASA Astrophysics Data System (ADS)

    Hsu, Hua-Ching; Lin, Chun-I.; Chen, Hsi-Kuei

    2004-02-01

    Zinc recovery from the spent zinc oxide catalyst by carbon in the presence of calcium carbonate was studied using an X-ray diffractometer (XRD), an atomic absorption spectrometer (AAS), and a scanning electron microscope (SEM). The spent zinc oxide catalyst was determined to be composed of 87.5 wt pct zinc oxide and 3.1 wt pct zinc sulfide. The results of X-ray diffractometry revealed that calcium carbonate decomposed to calcium oxide and carbon dioxide; zinc oxide and zinc sulfide were reduced to zinc vapor and carbon monoxide evolving from solid sample; and sulfur content was scavenged as calcium sulfide remained in the solid. Steps involved in this reaction system were summarized to explain the overall reaction. The experimental results of atomic absorption spectrometry showed that the initial rate of zinc recovery and final zinc recovery can be increased by increasing either the sample height, the reaction temperature or the initial bulk density. Furthermore, they were found to increase with decrease in either the argon flow rate, the molar ratio of Zntotal/C, the molar ratio of Zntotal/CaCO3, the grain size of the spent catalyst, the agglomerate size of carbon, or the agglomerate size of calcium carbonate. Empirical expressions of the initial rate of zinc recovery and final zinc recovery have been determined.

  18. Zinc deficiency in elderly patients.

    PubMed

    Prasad, A S; Fitzgerald, J T; Hess, J W; Kaplan, J; Pelen, F; Dardenne, M

    1993-01-01

    Zinc is needed for growth and development, DNA synthesis, neurosensory functions, and cell-mediated immunity. Although zinc intake is reduced in elderly people, its deficiency and effects on cell-mediated immunity of the elderly have not been established. Subjects enrolled in "A Model Health Promotion and Intervention Program for Urban Middle Aged and Elderly Americans" were assessed for nutrition and zinc status. One hundred eighty healthy subjects were randomly selected for the study. Their mean dietary zinc intake was 9.06 mg/day, whereas the recommended dietary allowance is 15 mg/day. Plasma zinc was normal, but zinc in granulocytes and lymphocytes were decreased compared with younger control subjects. Of 118 elderly subjects in whom zinc levels in both granulocytes and lymphocytes were available, 36 had deficient levels. Plasma copper was increased, and interleukin 1 (IL-1) production was significantly decreased. Reduced response to the skin-test antigen panel and decreased taste acuity were observed. Thirteen elderly zinc-deficient subjects were supplemented with zinc, and various variables were assessed before and after zinc supplementation. Zinc supplementation corrected zinc deficiency and normalized plasma copper levels. Serum thymulin activity, IL-1 production, and lymphocyte ecto-5'-nucleotidase increased significantly after supplementation. Improvement in response to skin-test antigens and taste acuity was observed after zinc supplementation. A mild zinc deficiency appears to be a significant clinical problem in free-living elderly people. PMID:8353362

  19. Interplay of TRIM28 and DNA methylation in controlling human endogenous retroelements.

    PubMed

    Turelli, Priscilla; Castro-Diaz, Nathaly; Marzetta, Flavia; Kapopoulou, Adamandia; Raclot, Charlène; Duc, Julien; Tieng, Vannary; Quenneville, Simon; Trono, Didier

    2014-08-01

    Reverse transcription-derived sequences account for at least half of the human genome. Although these retroelements are formidable motors of evolution, they can occasionally cause disease, and accordingly are inactivated during early embryogenesis through epigenetic mechanisms. In the mouse, at least for endogenous retroviruses, important mediators of this process are the tetrapod-specific KRAB-containing zinc finger proteins (KRAB-ZFPs) and their cofactor TRIM28. The present study demonstrates that KRAB/TRIM28-mediated regulation is responsible for controlling a very broad range of human-specific endogenous retroelements (EREs) in human embryonic stem (ES) cells and that it exerts, as a consequence, a marked effect on the transcriptional dynamics of these cells. It further reveals reciprocal dependence between TRIM28 recruitment at specific families of EREs and DNA methylation. It finally points to the importance of persistent TRIM28-mediated control of ERE transcriptional impact beyond their presumed inactivation by DNA methylation. PMID:24879559

  20. Dosage Effect of Zinc Glycine Chelate on Zinc Metabolism and Gene Expression of Zinc Transporter in Intestinal Segments on Rat.

    PubMed

    Huang, Danping; Hu, Qiaoling; Fang, Shenglin; Feng, Jie

    2016-06-01

    Zinc plays an essential role in various fundamental biological processes. The focus of this research was to investigate the dosage effect of zinc glycine chelate (Zn-Gly) on zinc metabolism and the gene expression of zinc transporters in intestinal segments. A total of 30 4-week-old SD rats were randomized into five treatment groups. The basal diets for each group were supplemented with gradient levels of Zn (0, 30, 60, 90, and 180 mg/kg) from Zn-Gly. After 1-week experiment, the results showed that serum and hepatic zinc concentration were elevated linearly with supplemental Zn levels from 0 to 180 mg Zn/kg. Serum Cu-Zn SOD activities resulted in a significant (P < 0.01) quadratic response and reached the peak when fed 60 mg Zn/kg. There were linear responses to the addition of Zn-Gly from 0 to 180 mg Zn/kg on Cu-Zn SOD and AKP activities in the liver. In the duodenum, MT1 mRNA was upregulated with the increasing dietary Zn-Gly levels and reached the peak of 180 mg Zn/kg (P < 0.05). Zip4 mRNA expression was downregulated with the increasing zinc levels (P < 0.05) in both duodenum and jejunum. In the jejunum, Zip5 mRNA expression in 60 mg Zn/kg was higher compared with other groups (P < 0.05). ZnT1 mRNA in duodenum was numerically increased with the rising levels of zinc content and was significantly higher (P < 0.05) with 180 mg Zn/kg. In the duodenum, adding 60 or 90 mg Zn/kg increased PepT1 expression, but in the jejunum, 60 mg Zn/kg did not differ from 0 added Zn. In summary, there is a dose-dependent effect of dietary Zn-Gly on serum and hepatic zinc levels and the activities of Cu-Zn SOD and AKP on rats. Dietary Zn-Gly has a certain effect on MT1, Zip4, Zip5, and ZnT1 expression, which expressed differently in intestinal segments with different levels of Zn-Gly load. Besides, Zn-Gly also could regulate PepT1 expression in intestinal segments. PMID:26507438

  1. ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, LOOKING NORTH. NOTE ONE STYLE OF DENVER AGITATOR IN LOWER RIGHT CELL. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  2. Suppression of zinc dendrites in zinc electrode power cells

    NASA Technical Reports Server (NTRS)

    Damjanovic, A.; Diggle, J. W.

    1970-01-01

    Addition of various tetraalkyl quarternary ammonium salts, to alkaline zincate electrolyte of cell, prevents formation of zinc dendrites during charging of zinc electrode. Electrode capacity is not impaired and elimination of dendrites prolongs cell life.

  3. Physiological concentrations of zinc reduce taurine-activated GlyR responses to drugs of abuse.

    PubMed

    Kirson, Dean; Cornelison, Garrett L; Philpo, Ashley E; Todorovic, Jelena; Mihic, S John

    2013-12-01

    Taurine is an endogenous ligand acting on glycine receptors in many brain regions, including the hippocampus, prefrontal cortex, and nucleus accumbens (nAcc). These areas also contain low concentrations of zinc, which is known to potentiate glycine receptor responses. Despite an increasing awareness of the role of the glycine receptor in the rewarding properties of drugs of abuse, the possible interactions of these compounds with zinc has not been thoroughly addressed. Two-electrode voltage-clamp electrophysiological experiments were performed on α1, α2 α1β and α2β glycine receptors expressed in Xenopus laevis oocytes. The effects of zinc alone, and zinc in combination with other positive modulators on the glycine receptor, were investigated when activated by the full agonist glycine versus the partial agonist taurine. Low concentrations of zinc enhanced responses of maximally-effective concentrations of taurine but not glycine. Likewise, chelation of zinc from buffers decreased responses of taurine- but not glycine-mediated currents. Potentiating concentrations of zinc decreased ethanol, isoflurane, and toluene enhancement of maximal taurine currents with no effects on maximal glycine currents. Our findings suggest that the concurrence of high concentrations of taurine and low concentrations of zinc attenuate the effects of additional modulators on the glycine receptor, and that these conditions are more representative of in vivo functioning than effects seen when these modulators are applied in isolation. PMID:23973295

  4. Physiological concentrations of zinc reduce taurine-activated GlyR responses to drugs of abuse

    PubMed Central

    Kirson, Dean; Cornelison, Garrett L.; Philpo, Ashley E.; Todorovic, Jelena; Mihic, S. John

    2013-01-01

    Taurine is an endogenous ligand acting on glycine receptors in many brain regions, including the hippocampus, prefrontal cortex, and nucleus accumbens (nAcc). These areas also contain low concentrations of zinc, which is known to potentiate glycine receptor responses. Despite an increasing awareness of the role of the glycine receptor in the rewarding properties of drugs of abuse, the possible interactions of these compounds with zinc has not been thoroughly addressed. Two-electrode voltage-clamp electrophysiological experiments were performed on α1, α2 α1β and a2β glycine receptors expressed in Xenopus laevis oocytes. The effects of zinc alone, and zinc in combination with other positive modulators on the glycine receptor, were investigated when activated by the full agonist glycine versus the partial agonist taurine. Low concentrations of zinc enhanced responses of maximally-effective concentrations of taurine but not glycine. Likewise, chelation of zinc from buffers decreased responses of taurine- but not glycine-mediated currents. Potentiating concentrations of zinc decreased ethanol, isoflurane, and toluene enhancement of maximal taurine currents with no effects on maximal glycine currents. Our findings suggest that the concurrence of high concentrations of taurine and low concentrations of zinc attenuate the effects of additional modulators on the glycine receptor, and that these conditions are more representative of in vivo functioning than effects seen when these modulators are applied in isolation. PMID:23973295

  5. Zinc absorption from zinc oxide, zinc sulfate, zinc oxide + EDTA, or sodium-zinc EDTA does not differ when added as fortificants to maize tortillas.

    PubMed

    Hotz, Christine; DeHaene, Jessica; Woodhouse, Leslie R; Villalpando, Salvador; Rivera, Juan A; King, Janet C

    2005-05-01

    The fortification of staple foods with zinc may play an important role in achieving adequate zinc intakes in countries at risk of zinc deficiency. However, little is known about the relative bioavailability of different zinc compounds that may be used in food fortification. The objective of this study was to measure and compare fractional zinc absorption from a test meal that included a maize tortilla fortified with zinc oxide, zinc sulfate, zinc oxide + EDTA, or sodium-zinc EDTA. A double isotopic tracer ratio method ((67)Zn as oral tracer and (70)Zn as intravenous tracer) was used to estimate zinc absorption in 42 Mexican women living in a periurban community of Puebla State, Mexico. The test meal consisted of maize tortillas, yellow beans, chili sauce, and milk with instant coffee; it contained 3.3 mg zinc and had a phytate:zinc molar ratio of 17. Fractional zinc absorption did not differ significantly between the test groups (ANOVA; P > 0.05). Percent absorptions were (mean +/- SD) zinc oxide, 10.8 +/- 0.9; zinc sulfate, 10.0 +/- 0.02; zinc oxide + EDTA, 12.7 +/- 1.5; and sodium-zinc EDTA, 11.1 +/- 0.7. We conclude that there was no difference in zinc absorption from ZnO and ZnSO(4) when added as fortificants to maize tortillas and consumed with beans and milk. The addition of EDTA with zinc oxide or the use of prechelated sodium-zinc EDTA as fortificants did not result in higher zinc absorption from the test meal. PMID:15867288

  6. Estimating the Global Prevalence of Inadequate Zinc Intake from National Food Balance Sheets: Effects of Methodological Assumptions

    PubMed Central

    Wessells, K. Ryan; Singh, Gitanjali M.; Brown, Kenneth H.

    2012-01-01

    Background The prevalence of inadequate zinc intake in a population can be estimated by comparing the zinc content of the food supply with the population’s theoretical requirement for zinc. However, assumptions regarding the nutrient composition of foods, zinc requirements, and zinc absorption may affect prevalence estimates. These analyses were conducted to: (1) evaluate the effect of varying methodological assumptions on country-specific estimates of the prevalence of dietary zinc inadequacy and (2) generate a model considered to provide the best estimates. Methodology and Principal Findings National food balance data were obtained from the Food and Agriculture Organization of the United Nations. Zinc and phytate contents of these foods were estimated from three nutrient composition databases. Zinc absorption was predicted using a mathematical model (Miller equation). Theoretical mean daily per capita physiological and dietary requirements for zinc were calculated using recommendations from the Food and Nutrition Board of the Institute of Medicine and the International Zinc Nutrition Consultative Group. The estimated global prevalence of inadequate zinc intake varied between 12–66%, depending on which methodological assumptions were applied. However, country-specific rank order of the estimated prevalence of inadequate intake was conserved across all models (r = 0.57–0.99, P<0.01). A “best-estimate” model, comprised of zinc and phytate data from a composite nutrient database and IZiNCG physiological requirements for absorbed zinc, estimated the global prevalence of inadequate zinc intake to be 17.3%. Conclusions and Significance Given the multiple sources of uncertainty in this method, caution must be taken in the interpretation of the estimated prevalence figures. However, the results of all models indicate that inadequate zinc intake may be fairly common globally. Inferences regarding the relative likelihood of zinc deficiency as a public health

  7. Zinc and its deficiency diseases.

    PubMed

    Evans, G W

    1986-01-01

    The pervasive role of zinc in the metabolic function of the body results from its function as a cofactor of a multitude of enzymes. Zinc is found in every tissue in the body, and because zinc metalloenzymes are found in every known class of enzymes, the metal has a function in every conceivable type of biochemical pathway. Symptoms resulting from zinc deficiency are as diverse as the enzymes with which the metal is associated. If chronic, severe, and untreated, zinc deficiency can be fatal. Less drastic symptoms include infections, hypogonadism, weight loss, emotional disturbance, dermatitis, alopecia, impaired taste acuity, night blindness, poor appetite, delayed wound healing, and elevated blood ammonia levels. Many symptoms of zinc deficiency result from poor diet consumption, but often the most severe symptoms result from other factors including excessive alcohol use, liver diseases, malabsorption syndromes, renal disease, enteral or parenteral alimentation, administration of sulfhydryl-containing drugs, and sickle cell disease. The most severe symptoms of zinc deficiency occur in young children affected with the autosomal-recessive trait, acrodermatitis enteropathica. This disease results in decreased synthesis of picolinic acid which causes an impaired ability to utilize zinc from common food. Because simple laboratory analyses are often not reliable in determining zinc nutriture of a patient, those symptoms caused by suspected zinc deficiency are best verified by the oral administration of zinc dipicolinate. This zinc compound is efficacious and safe and would provide an accurate means of identifying symptoms that do result from zinc deficiency. PMID:3514057

  8. Clinical manifestations of zinc deficiency.

    PubMed

    Prasad, A S

    1985-01-01

    The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal diseases, following uses of certain drugs such as penicillamine for Wilson's disease and diuretics in some cases, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. In pregnancy and during periods of growth the requirement of zinc is increased. The clinical manifestations in severe cases of zinc deficiency include bullous-pustular dermatitis, alopecia, diarrhea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males; it is fatal if unrecognized and untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities, and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss, and hyperammonemia. Zinc is a growth factor. Its deficiency adversely affects growth in many animal species and humans. Inasmuch as zinc is needed for protein and DNA synthesis and for cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Whether or not zinc is required for the metabolism of somatomedin needs to be investigated in the future. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level; the hypothalamic-pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in cell division, its deficiency may adversely affect testicular size and thus affect its functions. Zinc is required for the functions of several enzymes and whether or not it has an enzymatic role in steroidogenesis is not known at present

  9. Optimal dose of zinc supplementation for preventing aluminum-induced neurotoxicity in rats.

    PubMed

    Lu, Hao; Hu, Jianyang; Li, Jing; Pang, Wei; Hu, Yandan; Yang, Hongpeng; Li, Wenjie; Huang, Chengyu; Zhang, Mingman; Jiang, Yugang

    2013-10-15

    Zinc supplementation can help maintain learning and memory function in rodents. In this study, we hypothesized that zinc supplementation could antagonize the neurotoxicity induced by aluminum in rats. Animals were fed a diet containing different doses of zinc (50, 100, 200 mg/kg) for 9 weeks, and orally administered aluminum chloride (300 mg/kg daily) from the third week for 7 consecutive weeks. Open-field behavioral test results showed that the number of rearings in the group given the 100 mg/kg zinc supplement was significantly increased compared with the group given the 50 mg/kg zinc supplement. Malondialdehyde content in the cerebrum was significantly decreased, while dopamine and 5-hydroxytryptamine levels were increased in the groups given the diet supplemented with 100 and 200 mg/kg zinc, compared with the group given the diet supplemented with 50 mg/kg zinc. The acetylcholinesterase activity in the cerebrum was significantly decreased in the group given the 100 mg/kg zinc supplement. Hematoxylin-eosin staining revealed evident pathological damage in the hippocampus of rats in the group given the diet supplemented with 50 mg/kg zinc, but the damage was attenuated in the groups given the diet supplemented with 100 and 200 mg/kg zinc. Our findings suggest that zinc is a potential neuroprotective agent against aluminum-induced neurotoxicity in rats, and the optimal dosages are 100 and 200 mg/kg. PMID:25206586

  10. Zinc titanate sorbents

    DOEpatents

    Gupta, Raghubir P.; Gangwal, Santosh K.; Jain, Suresh C.

    1998-01-01

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750.degree. C. to about 950.degree. C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 .mu., and about 1 part titanium dioxide having a median particle size of less than about 1 .mu.. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  11. Zinc titanate sorbents

    DOEpatents

    Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

    1998-02-03

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750 to about 950 C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 microns, and about 1 part titanium dioxide having a median particle size of less than about 1 micron. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  12. The role of iron and zinc in chemotherapy-induced alopecia

    NASA Astrophysics Data System (ADS)

    Buyukavci, Mustafa; Gurol, Ali; Karabulut, Abdulhalik; Budak, Gokhan; Karacan, Mehmet

    2005-10-01

    Chemotherapy-induced alopecia is a common and distressing side effect in children with cancer. Iron and zinc are the well known trace elements which are associated with hair shedding. In this study, we investigated the hair content of iron and zinc in children with cancer consists of two groups: group A, newly diagnosed patients; group B, the patients received a course of chemotherapy. We compared the results between each others and healthy controls. Hair content of iron and zinc was not different between the patient groups. Iron concentrations of patient samples, either at diagnosis or after chemotherapy, were significantly lower than healthy controls. However, there was no statistically significant difference between the groups regarding the zinc values. In conclusion, hair content of iron and zinc do not have a role in chemotherapy-induced alopecia.

  13. Novel zinc alginate hydrogels prepared by internal setting method with intrinsic antibacterial activity.

    PubMed

    Straccia, Maria Cristina; d'Ayala, Giovanna Gomez; Romano, Ida; Laurienzo, Paola

    2015-07-10

    In this paper, a controlled gelation of alginate was performed for the first time using ZnCO3 and GDL. Uniform and transparent gels were obtained and investigated as potential wound dressings. Homogeneity, water content, swelling capability, water evaporation rate, stability in normal saline solution, mechanical properties and antibacterial activity were assessed as a function of zinc concentration. Gelation rate increased at increasing zinc content, while a decrease in water uptake and an improvement of stability were found. Release of zinc in physiological environments showed that concentration of zinc released in solution lies below the cytotoxicity level. Hydrogels showed antimicrobial activity against Escherichia coli. The hydrogel with highest zinc content was stabilized with calcium by immersion in a calcium chloride solution. The resulting hydrogel preserved homogeneity and antibacterial activity. Furthermore, it showed even an improvement of stability and mechanical properties, which makes it suitable as long-lasting wound dressing. PMID:25857965

  14. Nanomolar concentrations of zinc pyrithione increase cell susceptibility to oxidative stress induced by hydrogen peroxide in rat thymocytes.

    PubMed

    Oyama, Tomohiro M; Saito, Minoru; Yonezawa, Takayasu; Okano, Yoshiro; Oyama, Yasuo

    2012-06-01

    Zinc pyrithione is used as an antifouling agent. However, the environmental impacts of zinc pyrithione have recently been of concern. Zinc induces diverse actions during oxidative stress; therefore, we examined the effect of zinc pyrithione on rat thymocytes suffering from oxidative stress using appropriate fluorescent probes. The cytotoxicity of zinc pyrithione was not observed when the cells were incubated with 3 μM zinc pyrithione for 3 h. However, zinc pyrithione at nanomolar concentrations (10 nM or more) significantly increased the lethality of cells suffering from oxidative stress induced by 3 mM H(2)O(2). The application of zinc pyrithione alone at nanomolar concentrations increased intracellular Zn(2+) level and the cellular content of superoxide anions, and decreased the cellular content of nonprotein thiols. The simultaneous application of nanomolar zinc pyrithione and micromolar H(2)O(2) synergistically increased the intracellular Zn(2+) level. Therefore, zinc pyrithione at nanomolar concentrations may exert severe cytotoxic action on cells simultaneously exposed to chemicals that induce oxidative stress. If so, zinc pyrithione leaked from antifouling materials into surrounding environments would be a risk factor for aquatic ecosystems. Alternatively, zinc pyrithione under conditions of oxidative stress may become more potent antifouling ingredient. PMID:22356860

  15. History of zinc in agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc was established as essential for green plants in 1926 and for mammals in 1934. However, over 20 years would past before the first descriptions of zinc deficiencies in farm animals appeared. In 1955, it was reported that zinc supplementation would cure a parakeratosis in swine. In 1958, it wa...

  16. Recovering Zinc From Discarded Tires

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1984-01-01

    Zinc sulfate monohydrate sold at profit. Shredded tire material steeped in three sulfuric acid baths to extract zinc. Final product removed by evaporating part of solution until product crystallizes out. Recovered as zinc sulfate monohydrate and sold as fertilizer or for general use.

  17. Photovoltaic cells employing zinc phosphide

    DOEpatents

    Barnett, Allen M.; Catalano, Anthony W.; Dalal, Vikram L.; Masi, James V.; Meakin, John D.; Hall, Robert B.

    1984-01-01

    A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

  18. Zinc Phosphide Poisoning

    PubMed Central

    Doğan, Erdal; Güzel, Abdulmenap; Çiftçi, Taner; Aycan, İlker; Çetin, Bedri; Kavak, Gönül Ölmez

    2014-01-01

    Zinc phosphide has been used widely as a rodenticide. Upon ingestion, it gets converted to phosphine gas in the body, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. Phosphine gas produces various metabolic and nonmetabolic toxic effects. Clinical symptoms are circulatory collapse, hypotension, shock symptoms, myocarditis, pericarditis, acute pulmonary edema, and congestive heart failure. In this case presentation, we aim to present the intensive care process and treatment resistance of a patient who ingested zinc phosphide for suicide purposes. PMID:25101186

  19. Observations of interstellar zinc

    NASA Technical Reports Server (NTRS)

    Jura, M.; York, D.

    1981-01-01

    The International Ultraviolet Explorer observations of interstellar zinc toward 10 stars are examined. It is found that zinc is at most only slightly depleted in the interstellar medium; its abundance may serve as a tracer of the true metallicity in the gas. The local interstellar medium has abundances that apparently are homogeneous to within a factor of two, when integrated over paths of about 500 pc, and this result is important for understanding the history of nucleosynthesis in the solar neighborhood. The intrinsic errors in detecting weak interstellar lines are analyzed and suggestions are made as to how this error limit may be lowered to 5 mA per target observation.

  20. The mineralogical deportment of germanium in the Clarksville Electrolytic Zinc Plant of Savage Zinc Inc.

    SciTech Connect

    Dutrizac, J.E.; Chen, T.T.; Longton, R.J.

    1996-08-01

    Germanium is a strategic element which is widely used for infrared night vision systems, fiber optics, gamma-ray detectors, semiconductors, catalysts, and phosphors. Germanium is recovered from the dusts and residues generated during the processing of certain complex Zn-Cu-Pb sulfide ores or low-temperature sphalerite ores. A mineralogical study was carried out on the neutral leach residue and weak acid leach residue generated from Gordonsville zinc concentrate at the Clarksville Electrolytic Zinc Plant of Savage Zinc Inc. The intent was to characterize the mineral forms and associations of germanium. The Gordonsville zinc concentrate consists mostly of sphalerite which has a solid solution Ge content of {approximately} 400 ppm; the sphalerite is the dominant, if not only, Ge carrier in the concentrate. The major Ge carrier in the neutral residue is the iron gel-silica gel phase, but modest amounts of Ge are present in the ZnO, ZnFe{sub 2}O{sub 4}, sphalerite, and Zn-Fe-Pb silicate phases. The major Ge carrier in the acid residue is the iron gel-silica gel phase which contains up to 1.7% Ge and accounts for {approximately} 70% of the total Ge content of this residue. The remaining Ge is carried by the Zn-Fe-Pb silicate, ZnFe{sub 2}O{sub 4}, and some of the rare Mn-Pb-Fe oxide phases.

  1. The physiology of massive zinc accumulation in the liver of female squirrelfish and its relationship to reproduction.

    PubMed

    Hogstrand, C; Gassman, N J; Popova, B; Wood, C M; Walsh, P J

    1996-11-01

    It is well known that zinc is an essential micronutrient and, as a rule, organisms keep relatively constant low levels of zinc to maintain cellular functions. The squirrelfish family (Holocentridae) is the only known exception from this rule. Squirrelfish accumulate very high concentrations of zinc in the liver. In the present study, we demonstrate that, while female squirrelfish store large amounts of zinc in the liver and ovaries, the males show zinc levels that are typical for vertebrates. The zinc content of the diet is the same in males and females, and zinc is not lost from the liver during starvation. Thus, the difference between genders in zinc storage is not dependent upon the diet. Rather, there are at least two processes that contribute to the accumulation in females. First, females possess high levels of two major zinc-binding proteins: metallothionein (MT) and a novel female-specific zinc-binding protein (FZnBP). In females, but not in males, almost all MT is present in the hepatocyte nucleus. FZnBP is exclusively found in the hepatocyte cytosol of females. Second, hepatocytes of female squirrelfish have a high capacity to transport zinc across the plasma membrane. In addition to the liver, only the gonads of females showed unusually high concentrations of zinc. Administration of exogenous oestrogen to females decreases the hepatic zinc concentration while there is a matching increase in the zinc content of the ovaries. Thus, oestrogen may trigger a redistribution of zinc from liver to ovaries. Together, our findings suggest that female squirrelfish may be uniquely adapted to detoxify zinc and to utilize it as a macronutrient for processes related to reproduction. PMID:9114505

  2. Imaging Mobile Zinc in Biology

    PubMed Central

    Tomat, Elisa; Lippard, Stephen J.

    2009-01-01

    Summary Trafficking and regulation of mobile zinc pools influence cellular functions and pathological conditions in multiple organs, including brain, pancreas, and prostate. The quest for a dynamic description of zinc distribution and mobilization in live cells fuels the development of increasingly sophisticated probes. Detection systems that respond to zinc binding with changes of their fluorescence emission properties have provided sensitive tools for mobile zinc imaging, and fluorescence microscopy experiments have afforded depictions of zinc distribution within live cells and tissues. Both small-molecule and protein-based fluorescent probes can address complex imaging challenges, such as analyte quantification, site-specific sensor localization, and real-time detection. PMID:20097117

  3. Creep Resistant Zinc Alloy

    SciTech Connect

    Frank E. Goodwin

    2002-12-31

    This report covers the development of Hot Chamber Die Castable Zinc Alloys with High Creep Strengths. This project commenced in 2000, with the primary objective of developing a hot chamber zinc die-casting alloy, capable of satisfactory service at 140 C. The core objectives of the development program were to: (1) fill in missing alloy data areas and develop a more complete empirical model of the influence of alloy composition on creep strength and other selected properties, and (2) based on the results from this model, examine promising alloy composition areas, for further development and for meeting the property combination targets, with the view to designing an optimized alloy composition. The target properties identified by ILZRO for an improved creep resistant zinc die-casting alloy were identified as follows: (1) temperature capability of 1470 C; (2) creep stress of 31 MPa (4500 psi); (3) exposure time of 1000 hours; and (4) maximum creep elongation under these conditions of 1%. The project was broadly divided into three tasks: (1) Task 1--General and Modeling, covering Experimental design of a first batch of alloys, alloy preparation and characterization. (2) Task 2--Refinement and Optimization, covering Experimental design of a second batch of alloys. (3) Task 3--Creep Testing and Technology transfer, covering the finalization of testing and the transfer of technology to the Zinc industry should have at least one improved alloy result from this work.

  4. Zinc and Compounds

    Integrated Risk Information System (IRIS)

    Zinc and Compounds ; CASRN 7440 - 66 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  5. Zinc sulfide liquefaction catalyst

    DOEpatents

    Garg, Diwakar

    1984-01-01

    A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.

  6. The protective role of iron chelation and zinc supplements in atherosclerosis induced in New Zealand white rabbits: A nuclear microscopy study

    NASA Astrophysics Data System (ADS)

    Ren, M. Q.; Rajendran, R.; Pan, N.; Huat, B. T. K.; Halliwell, B.; Watt, F.

    2005-04-01

    The protective properties of iron chelator desferal and zinc supplements on atherosclerosis induced in New Zealand white rabbits were investigated using nuclear microscopy, incorporating particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and scanning transmission ion microscopy (STIM). Firstly, we examined the effects of the desferal (desferrioxamine - a chelator which forms a stable complex with ferric iron) on atherosclerosis progression and lesion iron content in cholesterol-fed New Zealand white rabbits. Rabbits were fed with a 1% w/w cholesterol diet (HFD - high fat diet) for either 8 weeks (with the last 5 weeks injected daily with desferal), or for 12 weeks (with the last 9 weeks injected with desferal). Controls were injected with saline. A significant reduction in average lesion area (p = 0.038) was observed in the 12-week treated animals as compared with the 12-week controls. The average lesion iron level of the 12 week treated animals (58 ppm dry weight) was significantly lower (p = 0.03) than for the 12-week control animals (95 ppm dry weight). No reduction in lesion area or iron content was observed in the 8 week treated animals compared with controls, and no change in lesion zinc concentration was observed for either group. This data is consistent with the concept that iron contributes to the early stages in the development of atherosclerosis and that removal of iron from the lesion retards the progression of the disease. Secondly, the effect of zinc supplements on atherosclerotic lesion growth was examined. The rabbits in the test group received a 1% w/w cholesterol diet with Zn supplements for 8 weeks and the rabbits in the control group were fed only with a 1% w/w cholesterol diet for the same period of time. Lesion area analyses using light microscopy showed that the average lesion area was 1.0 mm2 for the test models compared with 3.0 mm2 for the control group models (p = 0.0045). Elemental analysis of the lesion

  7. Hydrocracking with molten zinc chloride catalyst containing 2-12% ferrous chloride

    DOEpatents

    Zielke, Clyde W.; Bagshaw, Gary H.

    1981-01-01

    In a process for hydrocracking heavy aromatic polynuclear carbonaceous feedstocks to produce hydrocarbon fuels boiling below about 475.degree. C. by contacting the feedstocks with hydrogen in the presence of a molten zinc chloride catalyst and thereafter separating at least a major portion of the hydrocarbon fuels from the spent molten zinc chloride catalyst, an improvement comprising: adjusting the FeCl.sub.2 content of the molten zinc chloride to from about 2 to about 12 mol percent based on the mixture of ferrous chloride and molten zinc chloride.

  8. Tobacco/Nicotine and Endogenous Brain Opioids

    PubMed Central

    Xue, Yue; Domino, Edward F.

    2008-01-01

    Smoking is a major public health problem with devastating health consequences. Although many cigarette smokers are able to quit, equal numbers of others cannot! Standard medications to assist in smoking cessation, such as nicotine replacement therapies and bupropion, are ineffective in many remaining smokers. Recent developments in the neurobiology of nicotine dependence have identified several neurotransmitter systems that may contribute to the process of smoking maintenance and relapse. These include: especially dopamine, but also norepinephrine, 5-hydroxytryptamine, acetylcholine, endogenous opioids, gamma-aminobutyric acid (GABA), glutamate, and endocannabinoids. The present review examines the limited contribution of the endogenous opioid system to the complex effects of nicotine/tobacco smoking. PMID:18215788

  9. An endogenous model of the credit network

    NASA Astrophysics Data System (ADS)

    He, Jianmin; Sui, Xin; Li, Shouwei

    2016-01-01

    In this paper, an endogenous credit network model of firm-bank agents is constructed. The model describes the endogenous formation of firm-firm, firm-bank and bank-bank credit relationships. By means of simulations, the model is capable of showing some obvious similarities with empirical evidence found by other scholars: the upper-tail of firm size distribution can be well fitted with a power-law; the bank size distribution can be lognormally distributed with a power-law tail; the bank in-degrees of the interbank credit network as well as the firm-bank credit network fall into two-power-law distributions.

  10. Animal spirits, competitive markets, and endogenous growth

    NASA Astrophysics Data System (ADS)

    Miyazaki, Kenji

    2013-10-01

    This paper uses a simple model with an endogenous discount rate and linear technology to investigate whether a competitive equilibrium has a higher balanced growth path (BGP) than the social planning solution and whether the BGP is determinate or indeterminate. The implications are as follows. To start with, people with an instinct to compare themselves with others possess an endogenous discount rate. In turn, this instinct affects the economic growth rate in a competitive market economy. The competitive market economy also sometimes achieves higher economic growth than a social planning economy. However, the outcomes of market economy occasionally fluctuate because of the presence of the self-fulfilling prophecy or animal spirits.