Copper, lead and zinc concentrations of human breast milk as affected by maternal dietary practices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umoren, J.; Kies, C.

1986-03-01

Maternal dietary practices have been found to affect the concentrations of some nutrients in human breast milk. Lead toxicity is a concern in young children. Lead, copper and zinc are thought to compete for intestinal absorption sites. The objective of the current project was to compare copper, lead and zinc contents of breast milk from practicing lacto-vegetarian and omnivore, lactating women at approximately four months post-partum. Analyses were done by atomic absorption spectrophotometry using a carbon rod attachment. Copper concentrations were higher in milk samples from lacto-ovo-vegetarians. Milk samples from the omnivores had the highest lead and zinc concentrations. Leadmore » and copper concentrations in milk were negatively correlated. The higher zinc concentrations in the milk of the omnivore women may have been related to better utilization of zinc from meat than from plant food sources.« less

Severe zinc responsive dermatosis in a litter of Pharaoh Hounds.

PubMed

Campbell, Gregory A; Crow, Dennis

2010-07-01

A litter of 3-month-old Pharaoh Hound puppies presented to the referring veterinarian with severe generalized erythematous-crusted papules with pruritus, accompanied by exfoliation and erythema of footpads, inappetence, lethargy, and retarded growth. Three of 5 puppies (2 male and 1 female) were affected. Representative areas were biopsied from 1 affected male puppy and were routinely processed. Histologically, there was marked epidermal hyperplasia with a disorganized appearance of the epidermis and massive parakeratotic hyperkeratosis, compatible with zinc-responsive dermatosis. Low serum zinc concentrations were documented, and the affected animals partially responded to intravenous zinc supplementation but did not respond to oral supplementation. One male puppy died as a result of unrelated causes and was necropsied. The remaining 4 puppies were followed over 2 years. Growth was stunted, and enamel hypoplasia of permanent dentition developed compared with unaffected littermates. Intravenous zinc supplementation at 3-4 week intervals was required to prevent further skin lesion development. One dog died at 3 years of age of renal failure.

The linoleic acid: dihomo-y-linolenic acid ratio (LA:DGLA)— an emerging biomarker of Zn status

USDA-ARS?s Scientific Manuscript database

Zinc (Zn) deficiency is a common aliment predicted to affect 17% of the world’s population. Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. Although whole blood, plasma, and urine zinc decrease in severe zinc deficien...

Compositions of surface layers formed on amalgams in air, water, and saline.

PubMed

Hanawa, T; Gnade, B E; Ferracane, J L; Okabe, T; Watari, F

1993-12-01

The surface layers formed on both a zinc-free and a zinc-containing dental amalgam after polishing and aging in air, water, or saline, were characterized using x-ray photoelectron spectroscopy (XPS) to determine the compositions of the surface layers which might govern the release of mercury from amalgam. The XPS data revealed that the formation of the surface layer on the zinc-containing amalgam was affected by the environment in which the amalgam was polished and aged, whereas that on the zinc-free amalgam was not affected. In addition, among the elements contained in amalgam, zinc was the most reactive with the environment, and was preferentially dissolved from amalgam into water or saline. Mercury atoms existed in the metallic state in the surface layer.

Effect of hypotensive therapy combined with modified diet or zinc supplementation on biochemical parameters and mineral status in hypertensive patients.

PubMed

Suliburska, Joanna; Skrypnik, Katarzyna; Szulińska, Monika; Kupsz, Justyna; Bogdański, Paweł

2018-05-01

Hypotensive therapy leads to a number of trace elements metabolism disturbances. Zinc balance is frequently affected by antihypertensive treatment. To evaluate the effect of a hypotensive treatment, modified diet and zinc supplementation on mineral status and selected biochemical parameters in newly diagnosed hypertensive patients on monotherapy. In the first stage, arterial hypertension in ninety-eight human subjects was diagnosed. In the second stage, antihypertensive monopharmacotherapy was implemented. In the third stage, patients were randomized into three groups and continued antihypertensive monotherapy: group D received an optimal-mineral-content diet, group S received zinc supplementation, and group C had no changes in diet or zinc supplementation. Iron, zinc, and copper concentrations in serum, erythrocytes, urine, and hair were determined. Lipids, glucose, ceruloplasmin, ferritin, albumin, C-reactive protein (CRP), tumor necrosis factor α (TNF-α), nitric oxide (NO), superoxide dismutase (SOD) and catalase (CAT) were assayed in serum. Antihypertensive monotherapy decreased zinc concentration in serum and erythrocytes and increased the level of zinc in urine, decreased CAT and SOD activity, TNF-α concentration in serum, and increased the level of NO in the serum. Zinc supply led to an increase in zinc concentration in serum, erythrocytes, and hair (in group S only). In the groups with higher zinc intake, decreased glucose concentration in the serum was observed. Significant correlation was seen between the zinc and glucose serum concentrations. Hypotensive drugs disturb zinc status in newly diagnosed hypertensive patients. Antihypertensive monotherapy combined with increased zinc supply in the diet or supplementation favorably modify zinc homeostasis and regulate glucose status without blood pressure affecting in patients with hypertension. Copyright © 2018 Elsevier GmbH. All rights reserved.

Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron

PubMed Central

Rosado, Jorge L.; Díaz, Margarita; Muñoz, Elsa; Westcott, Jamie L.; González, Karla E.; Krebs, Nancy F.; Caamaño, María C.; Hambidge, Michael

2013-01-01

Background Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. Objective To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. Methods A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. Results The mean (± SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 ± 0.07, 0.36 ± 0.05, and 0.37 ± 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 ± 0.04, 0.33 ± 0.02, and 0.32 ± 0.05, respectively) and similar amounts of zinc absorbed (4.8 ± 0.7, 4.5 ± 0.3, and 4.8 ± 0.7 mg/day, respectively). Conclusions Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour. PMID:23424892

Altered Stem Cell Receptor Activity in the Ovarian Surface Epithelium by Exogenous Zinc and/or Progesterone.

PubMed

Oktem, G; Sahin, C; Dilsiz, O Y; Demiray, S B; Goker, E N T; Tavmergen, E

2015-05-01

Ovarian surface epithelium (OSE) has the characteristics of a stem cell and the potential for differentiation. Previous studies on this subject have succeeded in deriving oocytes from OSE stem cells, leading to the belief that OSE could be used for infertility treatment. Each rat (n = 10) was subjected to zinc and/or progesterone injection for 5 days after conception. After a 6-day implantation period, ovarian tissues were removed and comprehensive immunohistochemical analysis of stem cell markers was conducted: Sox2, Klf4, Oct3/4, c-Myc, CD117, CD90, SSEA-1 and Notch pathway analysis; Notch1, Jagged1, and Delta1 in the OSE and ovarian stromal cells were evaluated after treatment with zinc, progesterone, or both. Progesterone moderately affected Sox2 expression (p < 0.001), while zinc application strongly affected Klf4 and Oct3/4 and immunoreactivity (p < 0.001). CD90 immunoreactivity was decreased in the OSE and stroma of the progesterone group (p = 0.006) compared with the zinc (p = 0.244) and zinc/progesterone groups (p = 0.910). On the other hand, SSEA-1 showed moderate staining in the OSE and weak staining in stromal cells in animals treated with zinc (p = 0.727), progesterone (p = 0.626), and zinc/progesterone (p = 0.371), with no differences compared with control. Zinc application affected Notch pathway immunoreactivity, with a significant increase in Notch1 (p = 0.0015) and Jagged1 (p < 0.001). The expression of putative stem cell markers in the OSE was verified and stem cell receptor activity was raised in the OSE and ovarian stromal cells by zinc and progesterone. Thus, this increased expression allows the therapeutic use of zinc and progesterone in ovary-related infertility and brings a different perspective to reproductive medicine. © Georg Thieme Verlag KG Stuttgart · New York.

The influence of early postnatal nutrition on retinopathy of prematurity in extremely low birth weight infants.

PubMed

Porcelli, Peter J; Weaver, R Grey

2010-06-01

Retinopathy of prematurity(ROP) is the most common serious ophthalmic disease in preterm infants. Human milk may provide a protective effect for ROP; however, beneficial effects of human milk preclude randomized trials. Therefore, we conducted a retrospective analysis comparing early postnatal nutrition with ROP development. Evaluate relationship between early postnatal nutriture and ROP surgery. Nutrition data was collected for inborn AGA infants, BW 700-1000 g. ROP surgery was the primary outcome variable. A single pediatric ophthalmologist supervised examinations. All infants received triweekly IM vitamin A as chronic lung disease prophylaxis (Tyson: NEJM, 1999). BW and gestational age were 867+/-85 g and 26.3+/-1.2 weeks (n=77, mean+/-1SD). ROP surgery infants(n=11) received more parenteral nutrition, 1648 mL, and less human milk, 13.8 mL/kg-day, and vitamin E, 1.4 mg/kg-day, during the second postnatal week. Human milk was a negative predictor for ROP surgery, odds ratio=0.94. Both groups met vitamin A recommendations; however, 74% was administered via IM injections. Neither group met vitamin E recommendations. Human milk feeding, parenteral nutrition volume and vitamin E intake were predictors for ROP surgery. IM vitamin A injections provided the majority of vitamin A; vitamin E administration was insufficient. Improving human milk feeding rates and vitamin dosing options may affect ROP surgery rates. Copyright 2010 Elsevier Ltd. All rights reserved.

Extracellular chelation of zinc does not affect hippocampal excitability and seizure-induced cell death in rats

PubMed Central

Lavoie, Nathalie; Peralta, Modesto R; Chiasson, Marilou; Lafortune, Kathleen; Pellegrini, Luca; Seress, László; Tóth, Katalin

2007-01-01

In the nervous system, zinc can influence synaptic responses and at extreme concentrations contributes to epileptic and ischaemic neuronal injury. Zinc can originate from synaptic vesicles, the extracellular space and from intracellular stores. In this study, we aimed to determine which of these zinc pools is responsible for the increased hippocampal excitability observed in zinc-depleted animals or following zinc chelation. Also, we investigated the source of intracellularly accumulating zinc in vulnerable neurons. Our data show that membrane-permeable and membrane-impermeable zinc chelators had little or no effect on seizure activity in the CA3 region. Furthermore, extracellular zinc chelation could not prevent the accumulation of lethal concentrations of zinc in dying neurons following epileptic seizures. At the electron microscopic level, zinc staining significantly increased at the presynaptic membrane of mossy fibre terminals in kainic acid-treated animals. These data indicate that intracellular but not extracellular zinc chelators could influence neuronal excitability and seizure-induced zinc accumulation observed in the cytosol of vulnerable neurons. PMID:17095563

Zinc deficiency alters soybean susceptibility to pathogens and pests

USDA-ARS?s Scientific Manuscript database

Inadequate plant nutrition and biotic stress are key threats to current and future crop yields. Zinc deficiency and toxicity in major crop plants have been documented, but there is limited information on how pathogen and pest damage may be affected by differing plant zinc levels. In our study, we us...

Prenatal zinc supplementation of zinc-adequate rats adversely affects immunity in offspring

USDA-ARS?s Scientific Manuscript database

We previously showed that zinc (Zn) supplementation of Zn-adequate dams induced immunosuppressive effects that persist in the offspring after weaning. We investigated whether the immunosuppressive effects were due to in utero exposure and/or mediated via milk using a cross-fostering design. Pregnant...

Meals and dephytinization affect calcium and zinc absorption in Nigerian children with rickets

USDA-ARS?s Scientific Manuscript database

Nutritional rickets resulting from calcium insufficiency is common in Nigeria, and high dietary phytate is thought to inhibit calcium and zinc absorption. We compared the effects of a high-phytate meal and enzymatic dephytinization on calcium and zinc absorption in Nigerian children with and without...

Dietary zinc deficiency effects dorso-lateral and ventral prostate of Wistar rats: histological, biochemical and trace element study.

PubMed

Joshi, Sangeeta; Nair, Neena; Bedwal, R S

2014-10-01

Zinc deficiency has become a global problem affecting the developed and developing countries due to inhibitors in the diet which prevents its absorption or due to a very low concentration of bioavailable zinc in the diet. Being present in high concentration in the prostate and having diverse biological function, we investigated the effects of dietary zinc deficiency for 2 and 4 weeks on dorso-lateral and ventral prostate. Sixty prepubertal rats were divided into three groups: zinc control (ZC), pair fed (PF) and zinc deficient (ZD) and fed on 100 μg/g (zinc control and pair fed groups) and 1 μg/g (zinc deficient) diet. Zinc deficiency was associated with degenerative changes in dorso-lateral and ventral prostate as made evident by karyolysis, karyorhexis, cytoplasmolysis, loss of cellularisation, decreased intraluminar secretion and degeneration of fibromuscular stroma. In response, protein carbonyl, nitric oxide, acid phosphatase, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase increased, exhibiting variable level of significance. Total protein and total zinc concentration in dorso-lateral and ventral prostate as well as in serum decreased (P < 0.001). Decrease (P < 0.001) was recorded in serum FSH and testosterone after 2 and 4 weeks of zinc deficiency. The changes were more prominent after 4 weeks of synthetic zinc deficient diet. The results indicate that zinc deficiency during prepubertal period affects the prostate structure, total protein concentration, enhanced protein carbonyl concentration, nitric oxide as well as acid phosphatase activities and impaired hydroxysteroid dehydrogenase activities. Evidently these changes could be attributed to dysfunction of dorso-lateral and ventral prostate after dietary zinc deficiency as well as impairment of metabolic and secretory activity, reduced gonadotropin levels by hypothalamus -hypophysial system which is indicative of a critical role of zinc in maintaining the prostate integrity.

Effect of subchronic zinc toxicity on rat salivary glands and serum composition.

PubMed

Mizari, Nazer; Hirbod-Mobarakeh, Armin; Shahinpour, Shervin; Ghalichi-Tabriz, Mostafa; Beigy, Maani; Yamini, Ali; Dehpour, Ahmad Reza

2012-11-01

Zinc plays an important role in a wide variety of metabolic processes in animal systems. The role of zinc in preservative treatment, fungicidal action and medicine, and addition of supplementary zinc have increased the probability of zinc toxicity, specially the chronic type. It is known that the composition and quantity of saliva influence the oral health. Regarding people's exposure to zinc in routine life and the importance of saliva, our purpose was to investigate the effects of oral zinc intoxication on secretory function in rat salivary glands and also on serum composition. In this study, there were five groups of female rats. Four groups received zinc acetate dehydrate through their drinking water. After 3 months of experiment, the chemical characteristics and flow rate of saliva and weight of salivary glands were determined. The effects of zinc on hematological and chemical factors of plasma were assessed too. Flow rate of submandibular glands was significantly lower in experimental groups and there were significant changes in Na(+), Ca(2+) and K(+) concentration both in saliva and in plasma. The serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, glucose levels in the plasma and urine creatinine levels were also altered in experimental groups in comparison with the control group. Our results show that zinc toxicity will affect the quantity and quality of saliva probably through changes in the various neurologic pathways to the salivary glands or effects on acinar cells of the salivary glands. Furthermore, our results showed that zinc toxicity will affect the liver and renal function.

Interaction of zinc with dental mineral.

PubMed

Ingram, G S; Horay, C P; Stead, W J

1992-01-01

As some currently available toothpastes contain zinc compounds, the reaction of zinc with dental mineral and its effect on crystal growth rates were studied using three synthetic calcium-deficient hydroxyapatites (HAP) as being representative of dental mineral. Zinc was readily acquired by all HAP samples in the absence of added calcium, the amount adsorbed being proportional to the HAP surface area; about 9 mumol Zn/m2 was adsorbed at high zinc concentrations. As zinc was acquired, calcium was released, consistent with 1:1 Ca:Zn exchange. Soluble calcium reduced zinc uptake and similarly, calcium post-treatment released zinc. Pretreatment of HAP with 0.5 mM zinc reduced its subsequent ability to undergo seeded crystal growth, as did extracts of a toothpaste containing 0.5% zinc citrate, even in the presence of saliva. The reverse reaction, i.e. displacement of adsorbed zinc by salivary levels of calcium, however, indicates the mechanism by which zinc can reduce calculus formation in vivo by inhibiting plaque mineralisation without adversely affecting the anti-caries effects of fluoride.

[Advances in the research of zinc deficiency and zinc supplementation treatment in patients with severe burns].

PubMed

Wang, X X; Zhang, M J; Li, X B

2018-01-20

Zinc is one of the essential trace elements in human body, which plays an important role in regulating acute inflammatory response, glucose metabolism, anti-oxidation, immune and gastrointestinal function of patients with severe burns. Patients with severe burns may suffer from zinc deficiency because of insufficient amount of zinc intake from the diet and a large amount of zinc lose through wounds and urine. Zinc deficiency may affect their wound healing process and prognosis. This article reviews the characteristics of zinc metabolism in patients with severe burns through dynamic monitoring the plasma and urinary concentration of zinc. An adequate dosage of zinc supplemented to patients with severe burns by an appropriate method can increase the level of zinc in plasma and skin tissue and improve wound healing, as well as reduce the infection rates and mortality. At the same time, it is important to observe the symptoms and signs of nausea, dizziness, leukopenia and arrhythmia in patients with severe burns after supplementing excessive zinc.

Salty Taste Acuity Is Affected by the Joint Action of αENaC A663T Gene Polymorphism and Available Zinc Intake in Young Women

PubMed Central

Noh, Hwayoung; Paik, Hee-Young; Kim, Jihye; Chung, Jayong

2013-01-01

Salty taste perception affects salt intake, of which excess amounts is a major public health concern. Gene polymorphisms in salty taste receptors, zinc status and their interaction may affect salty taste perception. In this study, we examined the relationships among the α-epithelial sodium channel (αENaC) A663T genotype, zinc intake, and salty taste perception including salty taste acuity and preference in healthy young adults. The αENaC A663T genotype was determined by the PCR-restriction fragment length polymorphism in 207 adults. Zinc intake was examined by one 24-h recall and a two-day dietary record. Salty taste acuity and preference were determined by measuring the salty taste recognition threshold and the preferred salinity of beansprout soup, respectively. Men had significantly higher thresholds and preferences for salty taste than women did (p < 0.05). In women, the salty taste threshold was significantly lower in the highest tertile of available zinc intake than in the lowest tertile (12.2 mM and 17.6 mM, respectively, p = 0.02). Interestingly, a significant inverse association between available zinc intake and salty taste threshold was found only in women with αENaC AA homozygotes (β = −0.833, p = 0.02), and no such association was found in T663 allele carriers. The salty taste preference was not associated with the αENaC A663T genotype or available zinc intake in either sex. In conclusion, our data suggest that gene-nutrient interactions between the αENaC A663T genotype and available zinc intake play a role in determining the salty taste acuity in young women. PMID:24317554

Effect of dietary proteins on zinc bioavailability in pregnant rats.

PubMed

Uenishi, K; Horio, H; Manabe, S; Sakamoto, S

1993-12-01

In order to clarify the effects of dietary proteins on zinc bioavailability during pregnancy, two experiments were carried out. In Experiment 1, changes in zinc retention due to pregnancy (difference in retention between pregnant and nonpregnant animals) during early-mid and late pregnancy were examined in rats fed 10 and 20% egg white diets. Total amounts of retained zinc due to pregnancy were about 1000 micrograms or slightly more, equal to the zinc content in the products of conception at term. However, extra zinc retention during late pregnancy ranged between only 20 to 40% of overall retention, suggesting that almost all zinc retained during early-mid pregnancy moved from the mothers to the fetuses near term. Zinc retention in early-mid and late periods of pregnancy was higher in pregnant than nonpregnant rats, due mainly to increases in intake and bioavailability. In Experiment 2, to examine the effects of quality and quantity of dietary proteins, pregnant rats were fed either 10 or 20% egg white (EW), whole egg (WE), casein (C) and soy protein isolate with or without methionine (SM and S, respectively) diets. Total zinc retention during pregnancy was affected by both zinc and nitrogen intakes, though the former effect was greater than the latter. Because rats fed the EW diets retained dietary zinc efficiently, a relationship between zinc retention (Y, microgram/100 g BW/21 d.) and zinc intake (X, microgram/100 g BW/21 d.) was also examined in the non-EW protein groups, resulting in the following regression equation: Y = 0.471X-1790 (n: 51, r = 0.81, p < 0.001). Dietary protein quality affected the food intake resulting in different zinc intake and retention during pregnancy. Zinc from EW diets was more available than from the other four protein diets, because similar plots for rats fed the 10 and 20% EW diets fell above this line. Reasons for efficient bioavailability of zinc in EW were discussed in connection with the forms of zinc in diets and the pancreatic or intestinal responses to ingested EW.

Zinc transporter 7 deficiency affects lipid synthesis in adipocytes by inhibiting insulin-dependent Akt activity and glucose uptake

USDA-ARS?s Scientific Manuscript database

Mice deficient for zinc transporter 7 (Znt7) are mildly zinc deficient, accompanied with low body weight gain and body fat accumulation. To investigate the underlying mechanism of Znt7 deficiency in body adiposity, we investigated fatty acid composition and insulin sensitivity in visceral (epididyma...

Effects of Dietary Copper and Zinc Supplementation on Growth Performance, Tissue Mineral Retention, Antioxidant Status, and Fur Quality in Growing-Furring Blue Foxes (Alopex lagopus).

PubMed

Liu, Zhi; Wu, Xuezhuang; Zhang, Tietao; Guo, Jungang; Gao, Xiuhua; Yang, Fuhe; Xing, Xiumei

2015-12-01

A 4×2 factorial experiment with four supplemental levels of copper (0, 20, 40, or 60 mg copper per kg dry matter) from copper sulfate and two supplemental levels of zinc (40 or 200 mg zinc per kg dry matter) from zinc sulfate was conducted to investigate the effects of dietary copper and zinc supplementation on growth performance, tissue mineral retention, antioxidant status, and fur quality in growing-furring blue foxes. One hundred and twenty healthy 15-week-old male blue foxes were randomly allocated to eight dietary treatments with 15 replicates per treatment for a 70-day trial from mid-September to pelting in December. The average daily gain and feed conversion ratio were increased with copper supplementation in the first 35 days as well as the overall period (P<0.05). In addition, copper supplementation tended to increase feed intake during the first 35 days (P<0.10). Diets supplemented with 200 mg/kg zinc did not affect body gain (P>0.10) and feed intake (P>0.10) but improved feed conversion (P<0.05) compared with those supplemented 40 mg/kg zinc throughout the experiment. No copper×zinc interaction was observed for growth performance except that a tendency (P=0.09) was found for feed intake in the first 35 days. Supplementation of copper or zinc improved crude fat digestibility (P<0.01) but had no effects on the digestibility of other nutrients. Fecal copper was increased with both copper (P<0.01) and zinc addition (P<0.05). However, fecal zinc was affected only by dietary zinc addition (P<0.01). Mineral contents in serum and kidney were not affected by dietary treatments (P>0.05). However, the level of copper in the liver was increased with copper supplementation (P<0.05) and tended to decrease with zinc supplementation (P=0.08). Dietary zinc addition tended to increase the activity of alkaline phosphatase (P=0.07). The activities of copper-zinc superoxide dismutase and catalase tended to increase by copper (P=0.08) and zinc addition (P=0.05). Moreover, a copper×zinc interaction was observed for catalase in the experiment (P<0.05). Serum malondialdehyde concentration decreased with the increasing of dietary copper and zinc levels (P<0.05). The activity of glutathione peroxidase tended to increase by copper addition (P=0.09). For fur quality, foxes fed diets supplemented with high copper had larger skin length and darker pelts than those fed the basal diet without copper addition (P<0.05). In conclusion, this study demonstrated that dietary copper and zinc supplementation can improve growth by increasing feed intake and improving fat digestibility. Additionally, copper and zinc can enhance the antioxidant capacity of blue foxes. This study also indicates that additional zinc up to 200 mg/kg did not exert significant adverse effects on the copper metabolism of growing-furring blue foxes.

Zinc treatment increases the titre of 'Candidatus Liberibacter asiaticus' in huanglongbing-affected citrus plants while affecting the bacterial microbiomes

USDA-ARS?s Scientific Manuscript database

The bacterial microbiomes of citrus plants in response to ‘Candidatus Liberibacter asiaticus’ (Las)-infection and zinc treatments were deciphered by Phylochip-based metagenomics. The results indicated that 5,475 of over 50,000 known Operational Taxonomic Units (OTUs) in 52 phyla were detected in cit...

Could Zinc Whiskers Be Impacting Your Electronic Systems? Raise Your Awareness. Revision D

NASA Technical Reports Server (NTRS)

Sampson, Michael; Brusse, Jay

2003-01-01

During the past several decades electrical short circuits induced by "Zinc Whiskers" have been cited as the root cause of failure for various electronic systems (e.g., apnea monitors, telecom switches). These tiny filaments of zinc that may grow from some zinc-coated items (especially those coated by electroplating processes) have the potential to induce electrical shorts in exposed circuitry. Through this article, the authors describe a particular failure scenario attributed to zinc whiskers that has affected many facilities (including some NASA facilities) that utilized zinc-coated raised "access" floor tiles and support structures. Zinc whiskers that may be growing beneath your raised floor have the potential to wreak havoc on electronic systems operating above the floor.

[Study on X-ray powder diffraction of various structured zinc titanate prepared by the method of direct precipitation].

PubMed

Guo, Jian; Wang, Zhi-hua; Tao, Dong-liang; Guo, Guang-sheng

2007-05-01

Zinc titanate powders were prepared from Ti(SO4)2, Zn(NO3)2 x (6)H2O and (NH4)2CO3 by the method of direct precipitation. The effects of reaction conditions on the structure of zinc titanate were studied. The sample was analyzed by means of XRD and TG-DTA. The structure of zinc titanate was affected by the reaction subsequence of the formation of titanic acid and zinc carbonate. In the reaction system where titanic acid was generated earlier, collision reaction occurred between the generated zinc carbonate molecule and the surrounding titanic acid molecule. When titanic acid was generated earlier and precipitant (NH4)2CO3 was sufficient, Zn2Ti3O8 was obtained because of the sufficient collision reaction and superfluous titanic acid. In the reaction system where zinc carbonate was generated earlier, collision reaction occurred between the generated titanic acid molecule and the surrounding zinc carbonate molecule. When zinc carbonate was generated earlier and precipitant (NH4)2CO3 was sufficient, Zn2TiO4 was obtained because of the sufficient collision reaction and superfluous zinc carbonate. In addition, the kinds and structure of the production were affected by the dosage of precipitant and the reaction temperature. Zn2Ti3O8 or Zn2TiO4 could be obtained easier when using more precipitant or higher reaction temperature which could cause more sufficient collision reaction. ZnTiO3 could be obtained under the conditions of less precipitant and lower reaction temperature.

Zinc in human health: effect of zinc on immune cells.

PubMed

Prasad, Ananda S

2008-01-01

Although the essentiality of zinc for plants and animals has been known for many decades, the essentiality of zinc for humans was recognized only 40 years ago in the Middle East. The zinc-deficient patients had severe immune dysfunctions, inasmuch as they died of intercurrent infections by the time they were 25 years of age. In our studies in an experimental human model of zinc deficiency, we documented decreased serum testosterone level, oligospermia, severe immune dysfunctions mainly affecting T helper cells, hyperammonemia, neurosensory disorders, and decreased lean body mass. It appears that zinc deficiency is prevalent in the developing world and as many as two billion subjects may be growth retarded due to zinc deficiency. Besides growth retardation and immune dysfunctions, cognitive impairment due to zinc deficiency also has been reported recently. Our studies in the cell culture models showed that the activation of many zinc-dependent enzymes and transcription factors were adversely affected due to zinc deficiency. In HUT-78 (T helper 0 [Th(0)] cell line), we showed that a decrease in gene expression of interleukin-2 (IL-2) and IL-2 receptor alpha(IL-2Ralpha) were due to decreased activation of nuclear factor-kappaB (NF-kappaB) in zinc deficient cells. Decreased NF-kappaB activation in HUT-78 due to zinc deficiency was due to decreased binding of NF-kappaB to DNA, decreased level of NF-kappaB p105 (the precursor of NF-kappaB p50) mRNA, decreased kappaB inhibitory protein (IkappaB) phosphorylation, and decreased Ikappa kappa. These effects of zinc were cell specific. Zinc also is an antioxidant and has anti-inflammatory actions. The therapeutic roles of zinc in acute infantile diarrhea, acrodermatitis enteropathica, prevention of blindness in patients with age-related macular degeneration, and treatment of common cold with zinc have been reported. In HL-60 cells (promyelocytic leukemia cell line), zinc enhances the up-regulation of A20 mRNA, which, via TRAF pathway, decreases NF-kappaB activation, leading to decreased gene expression and generation of tumor necrosis factor-alpha (TNF-alpha), IL-1beta, and IL-8. We have reported recently that in both young adults and elderly subjects, zinc supplementation decreased oxidative stress markers and generation of inflammatory cytokines.

Copper, iron and zinc absorption, retention and status of young women fed vitamin B-6 deficient diets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnlund, J.R.; Keyes, W.R.; Hudson, C.A.

1991-03-11

A study was conducted in young women to determine the effect of vitamin B-6 deficient diets on copper, iron and zinc metabolism. Young women were confined to a metabolic research unit for 84 and 98 days. They were fed a vitamin B-6 deficient formula diet initially, followed by food diet containing four increasing levels of vitamin B-6. Copper, iron and zinc absorption, retention and status were determined at intervals throughout the study. Absorption was determined using the stable isotopes {sup 65}Cu, {sup 54}Fe, and {sup 67}Zn. Status was based on serum copper and zinc, hemoglobin, hematocrit and mean corpuscular volume.more » Copper absorption averaged 18 {plus minus} 1% during vitamin B-6 depletion, significantly lower than 24 {plus minus} 1% during repletion, but serum copper was not affected and balance was positive. Iron absorption was not impaired significantly by vitamin B-6 deficient diets, but status declined during the depletion period. Zinc absorption averaged 40 {plus minus} 2% during depletion and 27 {plus minus} 2% during repletion. Zinc absorption and retention were significantly greater during vitamin B-6 depletion, but serum zinc declined suggesting the absorbed zinc was not available for utilization. The results suggest that vitamin B-6 depletion of young women may inhibit copper absorption, affect iron status and alter zinc metabolism. The effects of vitamin B-6 depletion differ markedly among these elements.« less

Efficient zinc uptake is critical for the ability of Pseudomonas aeruginosa to express virulence traits and colonize the human lung.

PubMed

Mastropasqua, Maria Chiara; Lamont, Iain; Martin, Lois W; Reid, David W; D'Orazio, Melania; Battistoni, Andrea

2018-07-01

We have recently shown that Pseudomonas aeruginosa, an opportunistic pathogen that chronically infects the lungs of patients with cystic fibrosis (CF) and other forms of lung disease, is extremely efficient in recruiting zinc from the environment and that this capability is required for its ability to cause acute lung infections in mice. To verify that P. aeruginosa faces zinc shortage when colonizing the lungs of human patients, we analyzed the expression of three genes that are highly induced under conditions of zinc deficiency (zrmA, dksA2 and rpmE2), in bacteria in the sputum of patients with inflammatory lung disease. All three genes were expressed in all the analyzed sputum samples to a level much higher than that of bacteria grown in zinc-containing laboratory medium, supporting the hypothesis that P. aeruginosa is under zinc starvation during lung infections. We also found that the expression of several virulence traits that play a central role in the ability of P. aeruginosa to colonize the lung is affected by disruption of the most important zinc importing systems. Virulence features dependent on zinc intake include swarming and swimming motility and the ability to form biofilms. Furthermore, alterations in zinc assimilation interfere with the synthesis of the siderophore pyoverdine, suggesting that zinc recruitment could modulate iron uptake and affect siderophore-mediated cell signaling. Our results reveal that zinc uptake is likely to play a key role in the ability of P. aeruginosa to cause chronic lung infections and strongly modulates critical virulence traits of the pathogen. Taking into account the recent discovery that zinc uptake in P. aeruginosa is promoted by the release of a small molecular weight molecule showing high affinity for zinc, our data suggest novel and effective possibilities to control lung infections by these bacteria. Copyright © 2018 Elsevier GmbH. All rights reserved.

Morphology control of zinc regeneration for zinc-air fuel cell and battery

NASA Astrophysics Data System (ADS)

Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

2014-12-01

Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

Characterization of the zinc-induced Shank3 interactome of mouse synaptosome.

PubMed

Lee, Yeunkum; Ryu, Jae Ryun; Kang, Hyojin; Kim, Yoonhee; Kim, Shinhyun; Zhang, Yinhua; Jin, Chunmei; Cho, Hyo Min; Kim, Won-Ki; Sun, Woong; Han, Kihoon

2017-12-16

Variants of the SHANK3 gene, which encodes a core scaffold protein of the postsynaptic density of excitatory synapses, have been causally associated with numerous brain disorders. Shank3 proteins directly bind zinc ions through their C-terminal sterile α motif domain, which enhances the multimerization and synaptic localization of Shank3, to regulate excitatory synaptic strength. However, no studies have explored whether zinc affects the protein interactions of Shank3, which might contribute to the synaptic changes observed after zinc application. To examine this, we first purified Shank3 protein complexes from mouse brain synaptosomal lysates that were incubated with different concentrations of ZnCl 2 , and analyzed them with mass spectrometry. We used strict criteria to identify 71 proteins that specifically interacted with Shank3 when extra ZnCl 2 was added to the lysate. To characterize the zinc-induced Shank3 interactome, we performed various bioinformatic analyses that revealed significant associations of the interactome with subcellular compartments, including mitochondria, and brain disorders, such as bipolar disorder and schizophrenia. Together, our results showing that zinc affected the Shank3 protein interactions of in vitro mouse synaptosomes provided an additional link between zinc and core synaptic proteins that have been implicated in multiple brain disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Complementary feeding: clinically relevant factors affecting timing and composition.

PubMed

Krebs, Nancy F; Hambidge, K Michael

2007-02-01

Exclusive breastfeeding for the first 6 mo of life followed by optimal complementary feeding are critical public health measures for reducing and preventing morbidity and mortality in young children. Clinical factors, such as birth weight, prematurity, and illness, that affect the iron and zinc requirements of younger infants are discussed. Maternal diet and nutritional status do not have a strong effect on the mineral content of human milk, but physiologic changes in milk and the infants' status determine the dependence of the infant on complementary foods in addition to human milk to meet iron and zinc requirements after 6 mo. The nature of zinc absorption, which is suitably characterized by saturation response modeling, dictates that plant-based diets, which are low in zinc, are associated with low absolute daily absorbed zinc, which is inadequate to meet requirements. Foods with a higher zinc content, such as meats, are much more likely to be sufficient to meet dietary requirements. Current plant-based complementary feeding patterns for older fully breastfed infants in both developed and developing countries pose a risk of zinc deficiency. The strong rationale for the potential benefits of providing meat as an early complementary food, and the examples of successful intervention programs, provide potent incentives to pursue broader implementation programs, with concurrent rigorous evaluation of both efficacy and effectiveness.

Inhibition of vaccinia virus maturation by zinc chloride.

PubMed Central

Katz, E; Margalith, E

1981-01-01

Zinc chloride (0.1 mM) inhibited by 96.4% the growth of vaccinia virus in HeLa cells. Approximately 50% inhibition in formation of particles that sedimented in sucrose gradients similarly to vaccinia virions occurred in the presence of zinc ions. Whereas the synthesis of the viral deoxyribonucleic acid was not affected by zinc chloride, a decrease in the overall synthesis of viral polypeptides and inhibition of the cleavage of precursors to the core polypeptides were observed. Images PMID:7347557

The Zinc Concentration in the Diet and the Length of the Feeding Period Affect the Methylation Status of the ZIP4 Zinc Transporter Gene in Piglets

PubMed Central

Karweina, Diana; Kreuzer-Redmer, Susanne; Müller, Uwe; Franken, Tobias; Pieper, Robert; Baron, Udo; Olek, Sven; Zentek, Jürgen; Brockmann, Gudrun A.

2015-01-01

High doses of zinc oxide are commonly used in weaned pig diets to improve performance and health. Recent reports show that this may also lead to an imbalanced zinc homeostasis in the animal. For a better understanding of the regulatory mechanisms of different zinc intakes, we performed a feeding experiment to assess potential epigenetic regulation of the ZIP4 gene expression via DNA methylation in the small intestine of piglets. Fifty-four piglets were fed diets with 57 (LZn), 164 (NZn) or 2,425 (HZn) mg Zn/kg feed for one or four weeks. The ZIP4 expression data provided significant evidence for counter-regulation of zinc absorption with higher dietary zinc concentrations. The CpG +735 in the second exon had a 56% higher methylation in the HZn group compared to the others after one week of feeding (8.0·10-4 < p < 0.035); the methylation of this CpG was strongly negatively associated with the expression of the long ZIP4 transcripts (p < 0.007). In the LZn and NZn diets, the expression of the long ZIP4 transcripts were lower after four vs. one week of feeding (2.9·10-4 < p < 0.017). The strongest switch leading to high DNA methylation in nearly all analysed regions was dependent on feeding duration or age in all diet groups (3.7·10-10 < p < 0.099). The data suggest that DNA methylation serves as a fine-tuning mechanism of ZIP4 gene regulation to maintain zinc homeostasis. Methylation of the ZIP4 gene may play a minor role in the response to very high dietary zinc concentration, but may affect binding of alternate zinc-responsive transcription factors. PMID:26599865

Effects of Antioxidant Components of AREDS Vitamins and Zinc Ions on Endothelial Cell Activation: Implications for Macular Degeneration

PubMed Central

Zeng, Shemin; Hernández, Jasmine

2012-01-01

Purpose. To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Methods. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)–choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl2. The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. Results. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Conclusions. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation. PMID:22247465

Effects of antioxidant components of AREDS vitamins and zinc ions on endothelial cell activation: implications for macular degeneration.

PubMed

Zeng, Shemin; Hernández, Jasmine; Mullins, Robert F

2012-02-01

To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)-choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl(2). The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation.

Bone mineralization in childhood and adolescence.

PubMed

Bachrach, L K

1993-08-01

Prevention of osteoporosis depends on establishing adequate peak bone mass in the first two decades of life. Achievement of this goal requires an understanding of factors that promote skeletal health. Genetic factors are important determinants of adult bone mass, but nonheritable variables, including body mass, calcium nutriture, sex steroids, and activity can strongly influence whether maximal bone mineral is achieved. Acquisition of bone mineral continues throughout childhood and adolescence, reaching a lifetime maximum in early adulthood. Adolescence is a particularly critical time for bone mineral accretion as more than half of the bone calcium is normally laid down during the teen years. Chronic illness, malnutrition, or endocrine deficiencies at this age may result in profound deficits in bone mass, which may not be fully reversible. These risk factors contribute to the osteopenia associated with anorexia nervosa, exercise-induced amenorrhea, delayed puberty, Turner's syndrome, and growth hormone deficiency.

Zinc and Zinc Transporters: Novel Regulators of Ventricular Myocardial Development.

PubMed

Lin, Wen; Li, Deqiang

2018-06-01

Ventricular myocardial development is a well-orchestrated process involving different cardiac structures, multiple signal pathways, and myriad proteins. Dysregulation of this important developmental event can result in cardiomyopathies, such as left ventricle non-compaction, which affect the pediatric population and the adults. Human and mouse studies have shed light upon the etiology of some cardiomyopathy cases and highlighted the contribution of both genetic and environmental factors. However, the regulation of ventricular myocardial development remains incompletely understood. Zinc is an essential trace metal with structural, enzymatic, and signaling function. Perturbation of zinc homeostasis has resulted in developmental and physiological defects including cardiomyopathy. In this review, we summarize several mechanisms by which zinc and zinc transporters can impact the regulation of ventricular myocardial development. Based on our review, we propose that zinc deficiency and mutations of zinc transporters may underlie some cardiomyopathy cases especially those involving ventricular myocardial development defects.

Properties of ice-cream fortified with zinc and Lactobacillus casei.

PubMed

Gheisari, Hamid R; Ahadi, Leila; Khezli, Sanaz; Dehnavi, Tayebeh

2016-01-01

In this study, the possible effects of zinc on physicochemical properties of ice cream and the survival of Lactobacillus casei during a 90 days storage at -18°C was investigated. Samples were divided into four experimental groups as follows: control, zinc fortified ice cream, probiotic ice cream, zinc fortified and probiotic ice cream. The physicochemical, texture, organoleptic properties and the survival of probiotics, were investigated. Results showed that the addition of zinc did not affect the textural properties of ice creams. Viscosity and pH were independently decreased in all groups in the presence of zinc. A significant increase in the lipid oxidation rate especially in the zinc fortified group was also observed. The probiotic counts were maintained above the least advised quantities (106 cfu/g) which were subsequently reduced following the three months of storage. In the zinc fortified samples, the counts were higher compared to the other groups with no zinc addition. The addition of probiotics and zinc had no significant effect on the sensory properties of ice cream. As a final conclusion, the commercial production of zinc fortified ice cream is recommended.

Increased Zinc Availability Enhances Initial Aggregation and Biofilm Formation of Streptococcus pneumoniae.

PubMed

Brown, Lindsey R; Caulkins, Rachel C; Schartel, Tyler E; Rosch, Jason W; Honsa, Erin S; Schultz-Cherry, Stacey; Meliopoulos, Victoria A; Cherry, Sean; Thornton, Justin A

2017-01-01

Bacteria growing within biofilms are protected from antibiotics and the immune system. Within these structures, horizontal transfer of genes encoding virulence factors, and promoting antibiotic resistance occurs, making biofilms an extremely important aspect of pneumococcal colonization and persistence. Identifying environmental cues that contribute to the formation of biofilms is critical to understanding pneumococcal colonization and infection. Iron has been shown to be essential for the formation of pneumococcal biofilms; however, the role of other physiologically important metals such as copper, zinc, and manganese has been largely neglected. In this study, we investigated the effect of metals on pneumococcal aggregation and early biofilm formation. Our results show that biofilms increase as zinc concentrations increase. The effect was found to be zinc-specific, as altering copper and manganese concentrations did not affect biofilm formation. Scanning electron microscopy analysis revealed structural differences between biofilms grown in varying concentrations of zinc. Analysis of biofilm formation in a mutant strain lacking the peroxide-generating enzyme pyruvate oxidase, SpxB, revealed that zinc does not protect against pneumococcal H 2 O 2 . Further, analysis of a mutant strain lacking the major autolysin, LytA, indicated the role of zinc as a negative regulator of LytA-dependent autolysis, which could affect biofilm formation. Additionally, analysis of cell-cell aggregation via plating and microscopy revealed that high concentrations of zinc contribute to intercellular interaction of pneumococci. The findings from this study demonstrate that metal availability contributes to the ability of pneumococci to form aggregates and subsequently, biofilms.

Does zinc moderate essential fatty acid and amphetamine treatment of attention-deficit/hyperactivity disorder?

PubMed

Arnold, L E; Pinkham, S M; Votolato, N

2000-01-01

Zinc is an important co-factor for metabolism relevant to neurotransmitters, fatty acids, prostaglandins, and melatonin, and indirectly affects dopamine metabolism, believed intimately involved in attention-deficit/hyperactivity disorder (ADHD). To explore the relationship of zinc nutrition to essential fatty acid supplement and stimulant effects in treatment of ADHD, we re-analyzed data from an 18-subject double-blind, placebo-controlled crossover treatment comparison of d-amphetamine and Efamol (evening primrose oil, rich in gamma-linolenic acid). Subjects were categorized as zinc-adequate (n = 5), borderline zinc (n = 5), and zinc-deficient (n = 8) by hair, red cell, and urine zinc levels; for each category, placebo-active difference means were calculated on teachers' ratings. Placebo-controlled d-amphetamine response appeared linear with zinc nutrition, but the relationship of Efamol response to zinc appeared U-shaped; Efamol benefit was evident only with borderline zinc. Placebo-controlled effect size (Cohen's d) for both treatments ranged up to 1.5 for borderline zinc and dropped to 0.3-0.7 with mild zinc deficiency. If upheld by prospective research, this post-hoc exploration suggests that zinc nutrition may be important for treatment of ADHD even by pharmacotherapy, and if Efamol benefits ADHD, it likely does so by improving or compensating for borderline zinc nutrition.

Supplementation with zinc in rats enhances memory and reverses an age-dependent increase in plasma copper.

PubMed

Sandusky-Beltran, Leslie A; Manchester, Bryce L; McNay, Ewan C

2017-08-30

Zinc and copper are essential trace elements. Dyshomeostasis in these two metals has been observed in Alzheimer's disease, which causes profound cognitive impairment. Insulin therapy has been shown to enhance cognitive performance; however, recent data suggest that this effect may be at least in part due to the inclusion of zinc in the insulin formulation used. Zinc plays a key role in regulation of neuronal glutamate signaling, suggesting a possible link between zinc and memory processes. Consistent with this, zinc deficiency causes cognitive impairments in children. The effect of zinc supplementation on short- and long-term recognition memory, and on spatial working memory, was explored in young and adult male Sprague Dawley rats. After behavioral testing, hippocampal and plasma zinc and copper were measured. Age increased hippocampal zinc and copper, as well as plasma copper, and decreased plasma zinc. An interaction between age and treatment affecting plasma copper was also found, with zinc supplementation reversing elevated plasma copper concentration in adult rats. Zinc supplementation enhanced cognitive performance across tasks. These data support zinc as a plausible therapeutic intervention to ameliorate cognitive impairment in disorders characterized by alterations in zinc and copper, such as Alzheimer's disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

PubMed

Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

2016-04-25

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

Modulating the immune response by oral zinc supplementation: a single approach for multiple diseases.

PubMed

Overbeck, Silke; Rink, Lothar; Haase, Hajo

2008-01-01

Zinc is required for multiple cellular tasks, and especially the immune system depends on a sufficient availability of this essential trace element. During the last decades, many studies attempted to affect the outcome of various diseases by zinc supplementation. These efforts either aimed at supporting immunity by zinc administration or at correcting a loss of zinc secondary to the disease to restore the zinc-dependent functions of the immune system. This review aims to summarize the respective findings and to discuss possible molecular mechanisms by which zinc could influence viral, bacterial, and parasitic infections, autoimmune diseases, and the response to vaccination. Zinc supplementation in diseases such as diarrhea, chronic hepatitis C, shigellosis, leprosy, tuberculosis, pneumonia, acute lower respiratory infection, and leishmaniasis seems beneficial. In contrast, the results for the common cold and malaria are still not conclusive, and zinc was ineffective in most vaccination and rheumatoid arthritis studies. For AIDS and type 1 diabetes, zinc supplementation may even be a risk factor for increased mortality or deterioration of the glucose metabolism, respectively. In these cases, zinc supplementation should be used with care and limited to clearly zinc-deficient individuals.

Recent advances in knowledge of zinc nutrition and human health.

PubMed

Hess, Sonja Y; Lönnerdal, Bo; Hotz, Christine; Rivera, Juan A; Brown, Kenneth H

2009-03-01

Zinc deficiency increases the risk and severity of a variety of infections, restricts physical growth, and affects specific outcomes of pregnancy. Global recognition of the importance of zinc nutrition in public health has expanded dramatically in recent years, and more experience has accumulated on the design and implementation of zinc intervention programs. Therefore, the Steering Committee of the International Zinc Nutrition Consultative Group (IZiNCG) completed a second IZiNCG technical document that reexamines the latest information on the intervention strategies that have been developed to enhance zinc nutrition and control zinc deficiency. In particular, the document reviews the current evidence regarding preventive zinc supplementation and the role of zinc as adjunctive therapy for selected infections, zinc fortification, and dietary diversification or modification strategies, including the promotion and protection of breastfeeding and biofortification. The purposes of this introductory paper are to summarize new guidelines on the assessment of population zinc status, as recommended by the World Health Organization (WHO), the United Nations Children's Fund (UNICEF), the International Atomic Energy Agency (IAEA), and IZiNCG, and to provide an overview on several new advances in zinc metabolism. The following papers will then review the intervention strategies individually.

Zinc and its importance for human health: An integrative review

PubMed Central

Roohani, Nazanin; Hurrell, Richard; Kelishadi, Roya; Schulin, Rainer

2013-01-01

Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers), human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency. PMID:23914218

Diel cycling of zinc in a stream impacted by acid rock drainage: Initial results from a new in situ Zn analyzer

USGS Publications Warehouse

Chapin, T.P.; Nimick, D.A.; Gammons, C.H.; Wanty, R.B.

2007-01-01

Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 ??g/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage. ?? Springer Science+Business Media B.V. 2006.

Behavioral impairments in animal models for zinc deficiency

PubMed Central

Hagmeyer, Simone; Haderspeck, Jasmin Carmen; Grabrucker, Andreas Martin

2015-01-01

Apart from teratogenic and pathological effects of zinc deficiency such as the occurrence of skin lesions, anorexia, growth retardation, depressed wound healing, altered immune function, impaired night vision, and alterations in taste and smell acuity, characteristic behavioral changes in animal models and human patients suffering from zinc deficiency have been observed. Given that it is estimated that about 17% of the worldwide population are at risk for zinc deficiency and that zinc deficiency is associated with a variety of brain disorders and disease states in humans, it is of major interest to investigate, how these behavioral changes will affect the individual and a putative course of a disease. Thus, here, we provide a state of the art overview about the behavioral phenotypes observed in various models of zinc deficiency, among them environmentally produced zinc deficient animals as well as animal models based on a genetic alteration of a particular zinc homeostasis gene. Finally, we compare the behavioral phenotypes to the human condition of mild to severe zinc deficiency and provide a model, how zinc deficiency that is associated with many neurodegenerative and neuropsychological disorders might modify the disease pathologies. PMID:25610379

Low-Earth-Orbit (LEO) Life Cycle Evaluation of Nickel-Zinc Batteries

NASA Technical Reports Server (NTRS)

Coates, D.; Ferreira, E.; Nyce, M.; Charkey, A.

1997-01-01

The conclusion of the Low-Earth-Orbit (LEO) life cycle evaluation of nickel-zinc batteries are: that composite nickel electrode provide excellent performance at a reduced weight and lower cost; calcium / zinc electrode minimizes shape change; unioptimized cell designs yield 60 Wh/kg; nickel-zinc delivers 600 cycles at 80% DOD; long cycle life obtainable at low DOD; high rate capability power density; long-term failure mechanism is stack dry; and anomalous overcharge (1120%) greatly affected cell performance but did not induce failure and was recoverable.

Zinc Levels Modulate Lifespan through Multiple Longevity Pathways in Caenorhabditis elegans

PubMed Central

Kumar, Jitendra; Barhydt, Tracy; Awasthi, Anjali; Lithgow, Gordon J.; Killilea, David W.; Kapahi, Pankaj

2016-01-01

Zinc is an essential trace metal that has integral roles in numerous biological processes, including enzymatic function, protein structure, and cell signaling pathways. Both excess and deficiency of zinc can lead to detrimental effects on development and metabolism, resulting in abnormalities and disease. We altered the zinc balance within Caenorhabditis elegans to examine how changes in zinc burden affect longevity and healthspan in an invertebrate animal model. We found that increasing zinc levels in vivo with excess dietary zinc supplementation decreased the mean and maximum lifespan, whereas reducing zinc levels in vivo with a zinc-selective chelator increased the mean and maximum lifespan in C. elegans. We determined that the lifespan shortening effects of excess zinc required expression of DAF-16, HSF-1 and SKN-1 proteins, whereas the lifespan lengthening effects of the reduced zinc may be partially dependent upon this set of proteins. Furthermore, reducing zinc levels led to greater nuclear localization of DAF-16 and enhanced dauer formation compared to controls, suggesting that the lifespan effects of zinc are mediated in part by the insulin/IGF-1 pathway. Additionally, zinc status correlated with several markers of healthspan in worms, including proteostasis, locomotion and thermotolerance, with reduced zinc levels always associated with improvements in function. Taken together, these data support a role for zinc in regulating both development and lifespan in C. elegans, and that suggest that regulation of zinc homeostasis in the worm may be an example of antagonistic pleiotropy. PMID:27078872

Mining-Related Sediment and Soil Contamination in a Large Superfund Site: Characterization, Habitat Implications, and Remediation.

PubMed

Juracek, K E; Drake, K D

2016-10-01

Historical mining activity (1850-1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

Mining-Related Sediment and Soil Contamination in a Large Superfund Site: Characterization, Habitat Implications, and Remediation

NASA Astrophysics Data System (ADS)

Juracek, K. E.; Drake, K. D.

2016-10-01

Historical mining activity (1850-1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

Mining-related sediment and soil contamination in a large Superfund site: Characterization, habitat implications, and remediation

USGS Publications Warehouse

Juracek, Kyle E.; Drake, K. D.

2016-01-01

Historical mining activity (1850–1970) in the now inactive Tri-State Mining District provided an ongoing source of lead and zinc to the environment including the US Environmental Protection Agency Superfund site located in Cherokee County, southeast Kansas, USA. The resultant contamination adversely affected biota and caused human health problems and risks. Remediation in the Superfund site requires an understanding of the magnitude and extent of contamination. To provide some of the required information, a series of sediment and soil investigations were conducted in and near the Superfund site to characterize lead and zinc contamination in the aquatic and floodplain environments along the main-stem Spring River and its major tributaries. In the Superfund site, the most pronounced lead and zinc contamination, with concentrations that far exceed sediment quality guidelines associated with potential adverse biological effects, was measured for streambed sediments and floodplain soils located within or downstream from the most intensive mining-affected areas. Tributary streambeds and floodplains in affected areas are heavily contaminated with some sites having lead and zinc concentrations that are an order of magnitude (or more) greater than the sediment quality guidelines. For the main-stem Spring River, the streambed is contaminated but the floodplain is mostly uncontaminated. Measured lead and zinc concentrations in streambed sediments, lakebed sediments, and floodplain soils documented a persistence of the post-mining contamination on a decadal timescale. These results provide a basis for the prioritization, development, and implementation of plans to remediate contamination in the affected aquatic and floodplain environments within the Superfund site.

A dynamic model for predicting growth in zinc-deficient stunted infants given supplemental zinc.

PubMed

Wastney, Meryl E; McDonald, Christine M; King, Janet C

2018-05-01

Zinc deficiency limits infant growth and increases susceptibility to infections, which further compromises growth. Zinc supplementation improves the growth of zinc-deficient stunted infants, but the amount, frequency, and duration of zinc supplementation required to restore growth in an individual child is unknown. A dynamic model of zinc metabolism that predicts changes in weight and length of zinc-deficient, stunted infants with dietary zinc would be useful to define effective zinc supplementation regimens. The aims of this study were to develop a dynamic model for zinc metabolism in stunted, zinc-deficient infants and to use that model to predict the growth response when those infants are given zinc supplements. A model of zinc metabolism was developed using data on zinc kinetics, tissue zinc, and growth requirements for healthy 9-mo-old infants. The kinetic model was converted to a dynamic model by replacing the rate constants for zinc absorption and excretion with functions for these processes that change with zinc intake. Predictions of the dynamic model, parameterized for zinc-deficient, stunted infants, were compared with the results of 5 published zinc intervention trials. The model was then used to predict the results for zinc supplementation regimes that varied in the amount, frequency, and duration of zinc dosing. Model predictions agreed with published changes in plasma zinc after zinc supplementation. Predictions of weight and length agreed with 2 studies, but overpredicted values from a third study in which other nutrient deficiencies may have been growth limiting; the model predicted that zinc absorption was impaired in that study. The model suggests that frequent, smaller doses (5-10 mg Zn/d) are more effective for increasing growth in stunted, zinc-deficient 9-mo-old infants than are larger, less-frequent doses. The dose amount affects the duration of dosing necessary to restore and maintain plasma zinc concentration and growth.

Effect of the linkers between the zinc fingers in zinc finger protein 809 on gene silencing and nuclear localization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ichida, Yu, E-mail: ichida-y@ncchd.go.jp; Utsunomiya, Yuko; Onodera, Masafumi

2016-03-18

Zinc finger protein 809 (ZFP809) belongs to the Kruppel-associated box-containing zinc finger protein (KRAB-ZFP) family and functions in repressing the expression of Moloney murine leukemia virus (MoMLV). ZFP809 binds to the primer-binding site (PBS)located downstream of the MoMLV-long terminal repeat (LTR) and induces epigenetic modifications at integration sites, such as repressive histone modifications and de novo DNA methylation. KRAB-ZFPs contain consensus TGEKP linkers between C2H2 zinc fingers. The phosphorylation of threonine residues within linkers leads to the inactivation of zinc finger binding to target sequences. ZFP809 also contains consensus linkers between zinc fingers. However, the function of ZFP809 linkers remainsmore » unknown. In the present study, we constructed ZFP809 proteins containing mutated linkers and examined their ability to silence transgene expression driven by MLV, binding ability to MLV PBS, and cellular localization. The results of the present study revealed that the linkers affected the ability of ZFP809 to silence transgene expression. Furthermore, this effect could be partly attributed to changes in the localization of ZFP809 proteins containing mutated linkers. Further characterization of ZFP809 linkers is required for understanding the functions and features of KRAB-ZFP-containing linkers. - Highlights: • ZFP809 has three consensus linkers between the zinc fingers. • Linkers are required for ZFP809 to silence transgene expression driven by MLV-LTR. • Linkers affect the precise nuclear localization of ZFP809.« less

Increased Zinc Availability Enhances Initial Aggregation and Biofilm Formation of Streptococcus pneumoniae

PubMed Central

Brown, Lindsey R.; Caulkins, Rachel C.; Schartel, Tyler E.; Rosch, Jason W.; Honsa, Erin S.; Schultz-Cherry, Stacey; Meliopoulos, Victoria A.; Cherry, Sean; Thornton, Justin A.

2017-01-01

Bacteria growing within biofilms are protected from antibiotics and the immune system. Within these structures, horizontal transfer of genes encoding virulence factors, and promoting antibiotic resistance occurs, making biofilms an extremely important aspect of pneumococcal colonization and persistence. Identifying environmental cues that contribute to the formation of biofilms is critical to understanding pneumococcal colonization and infection. Iron has been shown to be essential for the formation of pneumococcal biofilms; however, the role of other physiologically important metals such as copper, zinc, and manganese has been largely neglected. In this study, we investigated the effect of metals on pneumococcal aggregation and early biofilm formation. Our results show that biofilms increase as zinc concentrations increase. The effect was found to be zinc-specific, as altering copper and manganese concentrations did not affect biofilm formation. Scanning electron microscopy analysis revealed structural differences between biofilms grown in varying concentrations of zinc. Analysis of biofilm formation in a mutant strain lacking the peroxide-generating enzyme pyruvate oxidase, SpxB, revealed that zinc does not protect against pneumococcal H2O2. Further, analysis of a mutant strain lacking the major autolysin, LytA, indicated the role of zinc as a negative regulator of LytA-dependent autolysis, which could affect biofilm formation. Additionally, analysis of cell-cell aggregation via plating and microscopy revealed that high concentrations of zinc contribute to intercellular interaction of pneumococci. The findings from this study demonstrate that metal availability contributes to the ability of pneumococci to form aggregates and subsequently, biofilms. PMID:28638805

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

Zinc status and cognitive function of pregnant women in Southern Ethiopia

PubMed Central

Stoecker, BJ; Abebe, Y; Hubbs-Tait, L; Kennedy, TS; Gibson, RS; Arbide, I; Teshome, A; Westcott, J; Krebs, NF; Hambidge, KM

2015-01-01

The relation between zinc status and cognitive function was examined in a cross-sectional study in the Sidama area of Southern Ethiopia. Pregnant women >24 weeks of gestation from three adjacent rural villages volunteered to participate. Mean (s.d.) plasma zinc of 99 women was 6.97 (1.07) μmol/l (below the cutoff of 7.6 μmol/l indicative of zinc deficiency at this stage of gestation). The Raven’s Coloured Progressive Matrices (CPM) test was administered individually. Scores for the Raven’s scale A, which is the simplest scale, ranged from 4 to 10 of a possible 12. Women with plasma zinc <7.6 μmol/l had significantly lower Raven’s CPM scale A scores than women with plasma zinc concentrations >7.6 μmol/l. Plasma zinc and maternal age and education predicted 17% of the variation in Raven’s CPM scale A scores. We conclude that zinc deficiency is a major factor affecting cognition in these pregnant women. PMID:19190668

A Photoluminescence Study of the Changes Induced in the Zinc White Pigment by Formation of Zinc Complexes

PubMed Central

Artesani, Alessia; Gherardi, Francesca; Nevin, Austin; Valentini, Gianluca; Comelli, Daniela

2017-01-01

It is known that oil paintings containing zinc white are subject to rapid degradation. This is caused by the interaction between the active groups of binder and the metal ions of the pigment, which gives rise to the formation of new zinc complexes (metal soaps). Ongoing studies on zinc white paints have been limited to the chemical mechanisms that lead to the formation of zinc complexes. On the contrary, little is known of the photo-physical changes induced in the zinc oxide crystal structure following this interaction. Time-resolved photoluminescence spectroscopy has been applied to follow modifications in the luminescent zinc white pigment when mixed with binder. Significant changes in trap state photoluminescence emissions have been detected: the enhancement of a blue emission combined with a change of the decay kinetic of the well-known green emission. Complementary data from molecular analysis of paints using Fourier transform infrared spectroscopy confirms the formation of zinc carboxylates and corroborates the mechanism for zinc complexes formation. We support the hypothesis that zinc ions migrate into binder creating novel vacancies, affecting the photoluminescence intensity and lifetime properties of zinc oxide. Here, we further demonstrate the advantages of a time-resolved photoluminescence approach for studying defects in semiconductor pigments. PMID:28772700

Effect of Dietary Zinc Oxide on Morphological Characteristics, Mucin Composition and Gene Expression in the Colon of Weaned Piglets

PubMed Central

Liu, Ping; Pieper, Robert; Rieger, Juliane; Vahjen, Wilfried; Davin, Roger; Plendl, Johanna; Meyer, Wilfried; Zentek, Jürgen

2014-01-01

The trace element zinc is often used in the diet of weaned piglets, as high doses have resulted in positive effects on intestinal health. However, the majority of previous studies evaluated zinc supplementations for a short period only and focused on the small intestine. The hypothesis of the present study was that low, medium and high levels of dietary zinc (57, 164 and 2,425 mg Zn/kg from zinc oxide) would affect colonic morphology and innate host defense mechanisms across 4 weeks post-weaning. Histological examinations were conducted regarding the colonic morphology and neutral, acidic, sialylated and sulphated mucins. The mRNA expression levels of mucin (MUC) 1, 2, 13, 20, toll-like receptor (TLR) 2, 4, interleukin (IL)-1β, 8, 10, interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were also measured. The colonic crypt area increased in an age-depending manner, and the greatest area was found with medium concentration of dietary zinc. With the high concentration of dietary zinc, the number of goblet cells containing mixed neutral-acidic mucins and total mucins increased. Sialomucin containing goblet cells increased age-dependently. The expression of MUC2 increased with age and reached the highest level at 47 days of age. The expression levels of TLR2 and 4 decreased with age. The mRNA expression of TLR4 and the pro-inflammatory cytokine IL-8 were down-regulated with high dietary zinc treatment, while piglets fed with medium dietary zinc had the highest expression. It is concluded that dietary zinc level had a clear impact on colonic morphology, mucin profiles and immunological traits in piglets after weaning. Those changes might support local defense mechanisms and affect colonic physiology and contribute to the reported reduction of post-weaning diarrhea. PMID:24609095

A question mark on zinc deficiency in 185 million people in Pakistan--possible way out.

PubMed

Khalid, Nauman; Ahmed, Anwaar; Bhatti, Muhammad Shahbaz; Randhawa, Muhammad Atif; Ahmad, Asif; Rafaqat, Rabab

2014-01-01

This paper reviews research published in recent years concerning the effects of zinc deficiency, its consequences, and possible solutions. Zinc is an essential trace element necessary for over 300 zinc metalloenzymes and required for normal nucleic acid, protein, and membrane metabolism. Zinc deficiency is one of the ten biggest factors contributing to burden of disease in developing countries. Populations in South Asia, South East Asia, and sub-Saharan Africa are at greatest risk of zinc deficiency. Zinc intakes are inadequate for about a third of the population and stunting affects 40% of preschool children. In Pakistan, zinc deficiency is an emerging health problem as about 20.6% children are found in the levels of zinc, below 60 μg/dL. Signs and symptoms caused by zinc deficiency are poor appetite, weight loss, and poor growth in childhood, delayed healing of wounds, taste abnormalities, and mental lethargy. As body stores of zinc decline, these symptoms worsen and are accompanied by diarrhea, recurrent infection, and dermatitis. Daily zinc requirements for an adult are 12-16 mg/day. Iron, calcium and phytates inhibit the absorption of zinc therefore simultaneous administration should not be prescribed. Zinc deficiency and its effects are well known but the ways it can help in treatment of different diseases is yet to be discovered. Improving zinc intakes through dietary improvements is a complex task that requires considerable time and effort. The use of zinc supplements, dietary modification, and fortifying foods with zinc are the best techniques to combat its deficiency.

Effect of iron and zinc deficiency on short term memory in children.

PubMed

Umamaheswari, K; Bhaskaran, Mythily; Krishnamurthy, Gautham; Vasudevan, Hemamalini; Vasudevan, Kavita

2011-04-01

To evaluate the effect of iron and zinc deficiency on short term memory of children in the age group of 6-11 years and to assess the response to supplementation therapy. Interventional study. 100 children in the age group of 6-11 years (subdivided into 6-8 yr and 9-11 yr groups) from an urban corporation school. After collection of demographic data, the study children underwent hematological assessment which included serum iron, serum zinc, and hemoglobin estimation. Based on the results, they were divided into Iron deficient, Zinc deficient, and Combined deficiency groups. Verbal and nonverbal memory assessment was done in all the children. Iron (2mg/kg bodyweight in two divided doses) and zinc (5mg once-a-day) supplementation for a period of 3 months for children in the deficient group. All children with iron and zinc deficiency in both the age groups had memory deficits. Combined deficiency in 9-11 years group showed severe degree of affectation in verbal (P<0.01) and non-verbal memory (P<0.01), and improved after supplementation (P = 0.05 and P< 0.01, respectively). In 6-8 years group, only non-verbal form of memory (P =0.02) was affected, which improved after supplementation. Iron and zinc deficiency is associated with memory deficits in children. There is a marked improvement in memory after supplementation. Post supplementation IQ scores do not show significant improvement in deficient groups in 6-8 year olds.

Correlation between the Severity and Type of Acne Lesions with Serum Zinc Levels in Patients with Acne Vulgaris

PubMed Central

Rostami Mogaddam, Majid; Safavi Ardabili, Nastaran; Soflaee, Maedeh

2014-01-01

Acne vulgaris is the most common cutaneous disorder affecting adolescents and young adults. Some studies have reported an association between serum zinc levels and acne vulgaris. We aimed to evaluate the serum zinc level in patients with acne vulgaris and compare it with healthy controls. One hundred patients with acne vulgaris and 100 healthy controls were referred to our clinic. Acne severity was classified according to Global Acne Grading System (GAGS). Atomic absorption spectrophotometry was used to measure serum zinc levels. Mean serum level of zinc in acne patients and controls was 81.31 ± 17.63 μg/dl and 82.63 ± 17.49 μg/dl, respectively. Although the mean serum zinc level was lower in acne group, it was not statistically significant (P = 0.598). There was a correlation between serum zinc levels with severity and type of acne lesions. The results of our study suggest that zinc levels may be related to the severity and type of acne lesions in patients with acne vulgaris. Relative decrease of serum zinc level in acne patients suggests a role for zinc in the pathogenesis of acne vulgaris. PMID:25157359

Correlation between the severity and type of acne lesions with serum zinc levels in patients with acne vulgaris.

PubMed

Rostami Mogaddam, Majid; Safavi Ardabili, Nastaran; Maleki, Nasrollah; Soflaee, Maedeh

2014-01-01

Acne vulgaris is the most common cutaneous disorder affecting adolescents and young adults. Some studies have reported an association between serum zinc levels and acne vulgaris. We aimed to evaluate the serum zinc level in patients with acne vulgaris and compare it with healthy controls. One hundred patients with acne vulgaris and 100 healthy controls were referred to our clinic. Acne severity was classified according to Global Acne Grading System (GAGS). Atomic absorption spectrophotometry was used to measure serum zinc levels. Mean serum level of zinc in acne patients and controls was 81.31 ± 17.63 μg/dl and 82.63 ± 17.49 μg/dl, respectively. Although the mean serum zinc level was lower in acne group, it was not statistically significant (P = 0.598). There was a correlation between serum zinc levels with severity and type of acne lesions. The results of our study suggest that zinc levels may be related to the severity and type of acne lesions in patients with acne vulgaris. Relative decrease of serum zinc level in acne patients suggests a role for zinc in the pathogenesis of acne vulgaris.

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

PubMed

Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

2017-06-01

The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P < 0.05) decrease in diet consumption, body weight and pituitary weight and decrease in gradation of intensity of zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

Effect of short-term zinc supplementation on zinc and selenium tissue distribution and serum antioxidant enzymes.

PubMed

Skalny, Andrey A; Tinkov, Alexey A; Medvedeva, Yulia S; Alchinova, Irina B; Karganov, Mikhail Y; Skalny, Anatoly V; Nikonorov, Alexandr A

2015-01-01

A significant association between Zn and Se homeostasis exists. At the same time, data on the influence of zinc supplementation on selenium distribution in organs and tissues seem to be absent. Therefore, the primary objective of the current study is to investigate the influence of zinc asparaginate supplementation on zinc and selenium distribution and serum superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in Wistar rats. 36 rats were used in the experiment. The duration of the experiment was 7 and 14 days in the first and second series, respectively. The rats in Group I were used as the control ones. Animals in Groups II and III daily obtained zinc asparaginate (ZnA) in the doses of 5 and 15 mg/kg weight, respectively. Zinc and selenium content in liver, kidneys, heart, muscle, serum and hair was assessed using inductively coupled plasma mass spectrometry. Serum SOD and GPx activity was analysed spectrophotometrically using Randox kits. Intragastric administration of zinc asparaginate significantly increased liver, kidney, and serum zinc content without affecting skeletal and cardiac muscle levels. Zinc supplementation also stimulated selenium retention in the rats' organs. Moreover, a significant positive correlation between zinc and selenium content was observed. Finally, zinc asparaginate treatment has been shown to modulate serum GPx but not SOD activity. The obtained data indicate that zinc-induced increase in GPx activity may be mediated through modulation of selenium status. However, future studies are required to estimate the exact mechanisms of zinc and selenium interplay.

Role of zinc in chronic gastritis.

PubMed

Marjanović, Ksenija; Dovhanj, Jasna; Kljaić, Ksenija; Sakić, Katarina; Kondza, Goran; Tadzić, Refmir; Vcev, Aleksandar

2010-06-01

Oxidative stress occurs in inflammation of gastric mucosa. The role of zinc in modulating oxidative stress has recently been recognized. Zn deficiency results in an increased sensitivity to oxidative stress and have a higher risk of musoca damage in inflammation. The aim of this study was to determine wheather chronic inflammation affects on the concentration of Zn2+ ions in gastric mucosa of patients with chronic gastritis. Forthy-three patients with chronic gastitis were enrolled. Patients were endoscoped. Histology and scoring of gastritis was performed following the guidelines of the updated Sydney system. Endoscopic finding of mucosa were scored according to a Lanza scoring system. The diagnosis of Helicobacter pylori (H. pylori) infection, histopathologic changes, intensity of inflammation and zinc concentration were determined from biopsies of gastric mucosa. The atomic absorption spectrophotometer was used to determine tissue concentrations of zinc. Twenty of 43 patients with chronic gastritis were uninfected by H. pylori. There was no statistically significant difference in tissue concentrations of zinc between H. pylori-positive and H. pylori-negative patients. From those infected patients 53.3% had chronic active gastritis. There was no statistically significant difference in tissue concentrations of zinc between patients with chronic active gastritis and patients with chronic inactive gastritis (p = 0.966). Zn in antrum showed positive correlation with density of H. pylori in antrum (Spearman' rho = 0.481, p = 0.020), negative correlation with density of H. pylori in corpus (Spearman' rho = -0.492, p = 0.017) and with zinc in corpus (Spearman' rho = 0.631, p =0.001). Tissue concentration of zinc was not affected by chronic inflammation of gastric mucosa in patients with chronic gastritis.

The lack of effects of zinc and nitric oxide in initial state of pilocarpine-induced seizures.

PubMed

Noyan, Behzat; Jensen, Morten Skovgaard; Danscher, Gorm

2007-07-01

In this study we investigated whether intracerebroventricular (i.c.v.) injection of L-NAME (a nitric oxide synthase inhibitor) or CaEDTA (an extracellular zinc chelator) or the combination of the two could affect the initial phase of pilocarpine induced (2 h) seizures. Two groups of rats were used. Animals from both groups were given with i.c.v. injections of either saline (10 microl), L-NAME (150 microg/10 microl), CaEDTA (100 mM/10 microl) or L-NAME and CaEDTA. One group received pilocarpine HCl (380 mg/kg i.p.) the other served as control. Pilocarpine HCl was injected intraperitoneally 10 min later. The behavior of the animals was observed for 2h and the intensity of their seizures was scored. The rats were then sacrificed and their brains were removed and analyzed for zinc ions by using the immersion autometallography and the TSQ fluorescence staining. All the animals which received pilocarpine HCl developed seizures. Despite treatment with L-NAME and/or CaEDTA we found that the latency and the intensity of seizures were similar in both groups investigated. The distribution of stainable zinc ions and the intensity of staining in hippocampus were not affected by pilocarpine and found unchanged after L-NAME and/or CaEDTA injections in both the control animals and the pilocarpine treated animals. The data suggest that the nitric oxide system and zinc ions do not affect pilocarpine-induced seizures in their initial state.

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. Copyright © 2015 Elsevier GmbH. All rights reserved.

Properties of Zip4 accumulation during zinc deficiency and its usefulness to evaluate zinc status: a study of the effects of zinc deficiency during lactation.

PubMed

Hashimoto, Ayako; Nakagawa, Miki; Tsujimura, Natsuki; Miyazaki, Shiho; Kizu, Kumiko; Goto, Tomoko; Komatsu, Yusuke; Matsunaga, Ayu; Shirakawa, Hitoshi; Narita, Hiroshi; Kambe, Taiho; Komai, Michio

2016-03-01

Systemic and cellular zinc homeostasis is elaborately controlled by ZIP and ZnT zinc transporters. Therefore, detailed characterization of their expression properties is of importance. Of these transporter proteins, Zip4 functions as the primarily important transporter to control systemic zinc homeostasis because of its indispensable function of zinc absorption in the small intestine. In this study, we closely investigated Zip4 protein accumulation in the rat small intestine in response to zinc status using an anti-Zip4 monoclonal antibody that we generated and contrasted this with the zinc-responsive activity of the membrane-bound alkaline phosphatase (ALP). We found that Zip4 accumulation is more rapid in response to zinc deficiency than previously thought. Accumulation increased in the jejunum as early as 1 day following a zinc-deficient diet. In the small intestine, Zip4 protein expression was higher in the jejunum than in the duodenum and was accompanied by reduction of ALP activity, suggesting that the jejunum can become zinc deficient more easily. Furthermore, by monitoring Zip4 accumulation levels and ALP activity in the duodenum and jejunum, we reasserted that zinc deficiency during lactation may transiently alter plasma glucose levels in the offspring in a sex-specific manner, without affecting homeostatic control of zinc metabolism. This confirms that zinc nutrition during lactation is extremely important for the health of the offspring. These results reveal that rapid Zip4 accumulation provides a significant conceptual advance in understanding the molecular basis of systemic zinc homeostatic control, and that properties of Zip4 protein accumulation are useful to evaluate zinc status closely. Copyright © 2016 the American Physiological Society.

Dietary Zinc Deficiency Affects Blood Linoleic Acid: Dihomo-γ-linolenic Acid (LA:DGLA) Ratio; a Sensitive Physiological Marker of Zinc Status in Vivo (Gallus gallus)

PubMed Central

Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P.; Tako, Elad

2014-01-01

Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn(+) (zinc adequate control, 42.3 μg/g zinc), and Zn(−) (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn(+) control versus Zn(−) group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn(+) control group (p < 0.05), and hepatic Δ6 desaturase was significantly higher in the Zn(+) group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn(−) group compared to the Zn(+) group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation. PMID:24658588

Dendrite-Free Nanocrystalline Zinc Electrodeposition from an Ionic Liquid Containing Nickel Triflate for Rechargeable Zn-Based Batteries.

PubMed

Liu, Zhen; Cui, Tong; Pulletikurthi, Giridhar; Lahiri, Abhishek; Carstens, Timo; Olschewski, Mark; Endres, Frank

2016-02-18

Metallic zinc is a promising anode material for rechargeable Zn-based batteries. However, the dendritic growth of zinc has prevented practical applications. Herein it is demonstrated that dendrite-free zinc deposits with a nanocrystalline structure can be obtained by using nickel triflate as an additive in a zinc triflate containing ionic liquid. The formation of a thin layer of Zn-Ni alloy (η- and γ-phases) on the surface and in the initial stages of deposition along with the formation of an interfacial layer on the electrode strongly affect the nucleation and growth of zinc. A well-defined and uniform nanocrystalline zinc deposit with particle sizes of about 25 nm was obtained in the presence of Ni(II) . Further, it is shown that the nanocrystalline Zn exhibits a high cycling stability even after 50 deposition/stripping cycles. This strategy of introducing an inorganic metal salt in ionic liquid electrolytes can be considered as an efficient way to obtain dendrite-free zinc. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Salmonella utilizes zinc to subvert anti-microbial host defense of macrophages via modulation of NF-κB signaling.

PubMed

Wu, Aimin; Tymoszuk, Piotr; Haschka, David; Heeke, Simon; Dichtl, Stefanie; Petzer, Verena; Seifert, Markus; Hilbe, Richard; Sopper, Sieghart; Talasz, Heribert; Bumann, Dirk; Lass-Flörl, Cornelia; Theurl, Igor; Zhang, Keying; Weiss, Guenter

2017-09-05

Zinc sequestration by macrophages is considered a crucial host defense strategy against infection with the intracellular bacterium Salmonella Typhimurium. However, the underlying mechanisms remain elusive. In this study we found zinc to favor pathogen survival within macrophages. Salmonella -hosting macrophages contained higher free zinc levels than uninfected macrophages and cells that successfully eliminated bacteria, which was paralleled by impaired production of reactive oxygen (ROS) and nitrogen (RNS) species in bacteria-harboring cells. A profound, zinc-mediated inhibition of NF-κB p65 transcriptional activity affecting expression of the ROS- and RNS-forming enzymes phos47 and iNOS provided a mechanistic explanation for this phenomenon. Macrophages responded to infection by enhanced expression of zinc scavenging methallothioneins-1 and 2, whose genetic deletion caused a rise of free zinc levels, reduced ROS and RNS production and increased survival of Salmonella Our data suggest that Salmonella invasion of macrophages results in a bacteria-driven rise of intracellular zinc levels which weakens anti-microbial defense and the ability of macrophages to eradicate the pathogen. Thus, limitation of cytoplasmic zinc levels may help to control infection with intracellular bacteria. Copyright © 2017 Wu et al.

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.

Zinc enhances intestinal epithelial barrier function through the PI3K/AKT/mTOR signaling pathway in Caco-2 cells.

PubMed

Shao, Yuxin; Wolf, Patricia G; Guo, Shuangshuang; Guo, Yuming; Gaskins, H Rex; Zhang, Bingkun

2017-05-01

Zinc plays an important role in maintaining intestinal barrier function as well as modulating cellular signaling recognition and protein kinase activities. The phosphatidylinositol 3-kinase (PI3K) cascade has been demonstrated to affect intercellular integrity and tight junction (TJ) proteins. The current study investigated the hypothesis that zinc regulates intestinal intercellular junction integrity through the PI3K/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. A transwell model of Caco-2 cell was incubated with 0, 50 and 100 μM of zinc at various time points. Transepithelial electrical resistance (TEER), paracellular permeability, TJ proteins, cell proliferation, differentiation and cell damage were measured. Compared with controls, 50 and 100 μM of zinc increased cell growth at 6, 12 and 24 h and the expression of proliferating cell nuclear antigen at 24 h. Zinc (100 μM) significantly elevated TEER at 6-24 h and reduced TJ permeability at 24 h, accompanied by the up-regulation of alkaline phosphatase (AP) activity and zonula occludens (ZO)-1 expression. In addition, zinc (100 μM) affected the PI3K/AKT/mTOR pathway by stimulating phosphorylation of AKT and the downstream target mTOR. Inhibition of PI3K signaling by LY294002 counteracted zinc promotion, as shown by a decrease in AP activity, TEER, the abundance of ZO-1 and phosphorylation of AKT and mTOR. Additionally, TJ permeability and the expression of caspase-3 and LC3II (markers of cell damage) were increased by addition of PI3K inhibitor. In conclusion, the activation of PI3K/AKT/mTOR signaling by zinc is involved in improving intestinal barrier function by enhancing cell differentiation and expression of TJ protein ZO-1. Copyright © 2017 Elsevier Inc. All rights reserved.

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate.

PubMed

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min; Chung, Tae Nyoung; Suh, Sang Won

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30  μ M and 100  μ M of ZnCl 2 . Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth.

Height, zinc and soil-transmitted helminth infections in schoolchildren: a study in Cuba and Cambodia.

PubMed

de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim; van der Werff, Suzanne D; D'Haese, Patrick C; Fiorentino, Marion; Khov, Kuong; Perignon, Marlene; Chamnan, Chhoun; Berger, Jacques; Parker, Megan E; Díaz, Raquel Junco; Núñez, Fidel Angel; Rivero, Lázara Rojas; Gorbea, Mariano Bonet; Doak, Colleen M; Ponce, Maiza Campos; Wieringa, Frank T; Polman, Katja

2015-04-20

Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children, plasma zinc was associated with height for age (aB-0.033, p = 0.029), but STH infection was not. Only in Cambodia, STH infection showed an association with zinc concentration (aB-0.233, p = 0.051). Factors influencing child growth differ between populations and may depend on prevalences of STH species and zinc deficiency. Further research is needed to elucidate these relationships and their underlying mechanisms.

Genomics of mineral nutrient biofortification: calcium, iron and zinc

USDA-ARS?s Scientific Manuscript database

Dietary deficiencies affect nearly half of the people on the planet, who simply do not receive sufficient nutrition from the food they buy or grow. Inadequate calcium, iron, and zinc consumption create short and long term health problems, which in turn can magnify and stagnate national development. ...

Evaluation of growth and biochemical indicators of Salvinia natans exposed to zinc oxide nanoparticles and zinc accumulation in plants.

PubMed

Hu, Changwei; Liu, Xu; Li, Xiuling; Zhao, Yongjun

2014-01-01

The adverse effects of zinc oxide nanoparticles (ZnO NPs) with an average diameter of 25 nm on the aquatic plant Salvinia natans (L.) All. were determined. Growth, superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase activity, and chlorophyll content of the plants were measured after 7 days of exposure to different concentrations of ZnO NPs (1 to 50 mg L(-1)). The particle distribution in the culture medium (without plants) during the first 24 h was determined using a Nanotrac 250 particle analyzer. We also investigated the zinc accumulation in leaves and roots of the plant after 7 days of exposure. Exposure to 50 mg L(-1) ZnO NPs significantly increased SOD and CAT activities (P < 0.05) and significantly depressed photosynthetic pigments (P < 0.05). However, plant growth was not significantly affected (P > 0.05). NPs completely precipitated at the bottom of the container at 8 h except for the portions of dissolution and aggregation on the roots. ZnO NPs at a concentration of 50 mg L(-1) can adversely affect S. natans, and their stress is affected by their aggregation and dissolution.

Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

PubMed

Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

2016-09-01

The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

Genetic causes and gene–nutrient interactions in mammalian zinc deficiencies: acrodermatitis enteropathica and transient neonatal zinc deficiency as examples.

PubMed

Kasana, Shakhenabat; Din, Jamila; Maret, Wolfgang

2015-01-01

Discovering genetic causes of zinc deficiency has been a remarkable scientific journey. It started with the description of a rare skin disease, its treatment with various agents, the successful therapy with zinc, and the identification of mutations in a zinc transporter causing the disease. The journey continues with defining the molecular and cellular pathways that lead to the symptoms caused by zinc deficiency. Remarkably, at least two zinc transporters from separate protein families are now known to be involved in the genetics of zinc deficiency. One is ZIP4, which is involved in intestinal zinc uptake. Its mutations can cause acrodermatitis enteropathica (AE) with autosomal recessive inheritance. The other one is ZnT2, the transporter responsible for supplying human milk with zinc. Mutations in this transporter cause transient neonatal zinc deficiency (TNZD) with symptoms similar to AE but with autosomal dominant inheritance. The two diseases can be distinguished in affected infants. AE is fatal if zinc is not supplied to the infant after weaning, whereas TNZD is a genetic defect of the mother limiting the supply of zinc in the milk, and therefore the infant usually will obtain enough zinc once weaned. Although these diseases are relatively rare, the full functional consequences of the numerous mutations in ZIP4 and ZnT2 and their interactions with dietary zinc are not known. In particular, it remains unexplored whether some mutations cause milder disease phenotypes or increase the risk for other diseases if dietary zinc requirements are not met or exceeded. Thus, it is not known whether widespread zinc deficiency in human populations is based primarily on a nutritional deficiency or determined by genetic factors as well. This consideration becomes even more significant with regard to mutations in the other 22 human zinc transporters, where associations with a range of diseases, including diabetes, heart disease, and mental illnesses have been observed. Therefore, clinical tests for genetic disorders of zinc metabolism need to be developed.

An overview of methods for assessment of iron bioavailability from foods nutritionally enhanced through biotechnology.

PubMed

Cockell, Kevin A

2007-01-01

Iron deficiency and iron deficiency anemia continue to be significant public health problems worldwide. While supplementation and fortification have been viable means to improve iron nutriture of the population in developed countries, they may be less successful in developing regions for a number of reasons, including complexities in distribution and consumer compliance. Biofortification of staple crops, through conventional plant breeding strategies or modern methods of biotechnology, provides an alternative approach that may be more sustainable once initial investments have been made. Three types of biofortification strategies are being essayed, singly or in combination: increasing the total iron content of edible portions of the plant, decreasing the levels of inhibitors of iron absorption, and increasing the levels of factors that enhance iron absorption. Bioavailability is a key concept in iron nutrition, particularly for nonheme iron such as is found in these biofortified foods. An overview is presented of methods for evaluation of iron bioavailability from foods nutritionally enhanced through biotechnology.

Combinatorial effects of zinc deficiency and arsenic exposure on zebrafish (Danio rerio) development

PubMed Central

Truong, Lisa; Barton, Carrie L.; Chase, Tyler T.; Gonnerman, Greg D.; Wong, Carmen P.; Tanguay, Robert L.; Ho, Emily

2017-01-01

Zinc deficiency and chronic low level exposures to inorganic arsenic in drinking water are both significant public health concerns that affect millions of people including pregnant women. These two conditions can co-exist in the human population but little is known about their interaction, and in particular, whether zinc deficiency sensitizes individuals to arsenic exposure and toxicity, especially during critical windows of development. To address this, we utilized the Danio rerio (zebrafish) model to test the hypothesis that parental zinc deficiency sensitizes the developing embryo to low-concentration arsenic toxicity, leading to altered developmental outcomes. Adult zebrafish were fed defined zinc deficient and zinc adequate diets and were spawned resulting in zinc adequate and zinc deficient embryos. The embryos were treated with environmentally relevant concentrations of 0, 50, and 500 ppb arsenic. Arsenic exposure significantly reduced the amount of zinc in the developing embryo by ~7%. The combination of zinc deficiency and low-level arsenic exposures did not sensitize the developing embryo to increased developmental malformations or mortality. The combination did cause a 40% decline in physical activity of the embryos, and this decline was significantly greater than what was observed with zinc deficiency or arsenic exposure alone. Significant changes in RNA expression of genes that regulate zinc homeostasis, response to oxidative stress and insulin production (including zip1, znt7, nrf2, ogg1, pax4, and insa) were found in zinc deficient, or zinc deficiency and arsenic exposed embryos. Overall, the data suggests that the combination of zinc deficiency and arsenic exposure has harmful effects on the developing embryo and may increase the risk for developing chronic diseases like diabetes. PMID:28837703

Gender Dependent Evaluation of Autism like Behavior in Mice Exposed to Prenatal Zinc Deficiency

PubMed Central

Grabrucker, Stefanie; Boeckers, Tobias M.; Grabrucker, Andreas M.

2016-01-01

Zinc deficiency has recently been linked to the etiology of autism spectrum disorders (ASD) as environmental risk factor. With an estimated 17% of the world population being at risk of zinc deficiency, especially zinc deficiency during pregnancy might be a common occurrence, also in industrialized nations. On molecular level, zinc deficiency has been shown to affect a signaling pathway at glutamatergic synapses that has previously been identified through genetic mutations in ASD patients, the Neurexin-Neuroligin-Shank pathway, via altering zinc binding Shank family members. In particular, prenatal zinc deficient but not acute zinc deficient animals have been reported to display autism like behavior in some behavioral tests. However, a full behavioral analysis of a possible autism like behavior has been lacking so far. Here, we performed an extensive behavioral phenotyping of mice born from mothers with mild zinc deficiency during all trimesters of pregnancy. Prenatal zinc deficient animals were investigated as adults and gender differences were assessed. Our results show that prenatal zinc deficient mice display increased anxiety, deficits in nest building and various social interaction paradigm, as well as mild alterations in ultrasonic vocalizations. A gender specific analysis revealed only few sex specific differences. Taken together, given that similar behavioral abnormalities as reported here are frequently observed in ASD mouse models, we conclude that prenatal zinc deficient animals even without specific genetic susceptibility for ASD, already show some features of ASD like behavior. PMID:26973485

Responses of Pseudomonas putida to Zinc Excess Determined at the Proteome Level: Pathways Dependent and Independent of ColRS.

PubMed

Mumm, Karl; Ainsaar, Kadi; Kasvandik, Sergo; Tenson, Tanel; Hõrak, Rita

2016-12-02

Zinc is an important micronutrient for bacteria, but its excess is toxic. Recently, the ColRS two-component system was shown to detect and respond to zinc excess and to contribute to zinc tolerance of Pseudomonas putida. Here, we applied a label-free whole-cell proteome analysis to compare the zinc-induced responses of P. putida and colR knockout. We identified dozens of proteins that responded to zinc in a ColR-independent manner, among others, known metal efflux systems CzcCBA1, CzcCBA2, CadA2 and CzcD. Nine proteins were affected in a ColR-dependent manner, and besides known ColR targets, four new candidates for ColR regulon were identified. Despite the relatively modest ColR-dependent changes of wild-type, colR deficiency resulted in drastic proteome alterations, with 122 proteins up- and 62 down-regulated by zinc. This zinc-promoted response had remarkable overlap with the alternative sigma factor AlgU-controlled regulon in P. aeruginosa. The most prominent hallmark was a high induction of alginate biosynthesis proteins and regulators. This response likely alleviates the zinc stress, as the AlgU-regulated alginate regulator AmrZ was shown to contribute to zinc tolerance of colR knockout. Thus, the ColRS system is important for zinc homeostasis, and in its absence, alternative stress response pathways are activated to support the zinc tolerance.

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 problem in different countries can be drawn based on the country-specific rank order of estimated prevalence of inadequate zinc intake. PMID:23209781

DOE Office of Scientific and Technical Information (OSTI.GOV)

Svensson, Emelie; Eriksson, Helena; Gekas, Christos

The Wilms tumor gene 1 (WT1) encodes a zinc-finger-containing transcription factor highly expressed in immature hematopoietic progenitor cells. Overexpression and presence of somatic mutations in acute leukemia indicate a role for WT1 in the pathogenesis of leukemia. CD34{sup +} progenitor cells were transduced with one splice variant of human WT1 without the KTS insert in the zinc-finger domain, WT1(+/-), and with a deleted mutant of WT1 lacking the entire zinc-finger region, WT1(delZ), thus incapable of binding DNA. We show that inhibition of erythroid colony formation and differentiation is absolutely dependent on the DNA-binding zinc-finger domain of WT1. Unexpectedly, however, WT1(delZ)more » was equally effective as wild type protein in the reduction of myeloid clonogenic growth as well as in stimulation of myeloid differentiation, as judged by the expression of cell surface CD11b. Expression of neither WT1(+/-) nor WT1(delZ) upregulated mRNA for the cdk inhibitor p21{sup Waf1/Cip1} or p27{sup Kip1}. Our results demonstrate that WT1 affects proliferation and differentiation in erythroid and myeloid cells by different molecular mechanisms, and suggest that mutations affecting the zinc-finger domain of WT1 could interfere with normal differentiation in the pathogenesis of leukemia.« less

Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

NASA Astrophysics Data System (ADS)

Acarali, Nil Baran; Bardakci, Melek; Tugrul, Nurcan; Derun, Emek Moroydor; Piskin, Sabriye

2013-06-01

The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120°C), cooling temperature (10-80°C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (1wt%-6wt%), and oleic acid (OA, 1wt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.

New perspectives on the regulation of iron absorption via cellular zinc concentrations in humans.

PubMed

Knez, Marija; Graham, Robin D; Welch, Ross M; Stangoulis, James C R

2017-07-03

Iron deficiency is the most prevalent nutritional deficiency, affecting more than 30% of the total world's population. It is a major public health problem in many countries around the world. Over the years various methods have been used with an effort to try and control iron-deficiency anemia. However, there has only been a marginal reduction in the global prevalence of anemia. Why is this so? Iron and zinc are essential trace elements for humans. These metals influence the transport and absorption of one another across the enterocytes and hepatocytes, due to similar ionic properties. This paper describes the structure and roles of major iron and zinc transport proteins, clarifies iron-zinc interactions at these sites, and provides a model for the mechanism of these interactions both at the local and systemic level. This review provides evidence that much of the massive extent of iron deficiency anemia in the world may be due to an underlying deficiency of zinc. It explains the reasons for predominance of cellular zinc status in determination of iron/zinc interactions and for the first time thoroughly explains mechanisms by which zinc brings about these changes.

Effects of Zinc Gluconate and 2 Other Divalent Cationic Compounds on Olfactory Function in Mice

PubMed Central

Duncan-Lewis, Christopher A; Lukman, Roy L; Banks, Robert K

2011-01-01

Intranasal application of zinc gluconate has commonly been used to treat the common cold. The safety of this treatment, however, has come into question recently. In addition to a United States recall of a homeopathic product that contains zinc gluconate, abundant literature reports cytotoxic effects of zinc on the olfactory epithelium. Additional research suggests that divalent cations (such as zinc) can block ion channels that facilitate the transduction of odors into electrical signals on the olfactory epithelium. The purpose of the current study was 2-fold: to confirm whether zinc gluconate causes anosmia and to reveal whether any other divalent cationic compounds produce a similar effect. Groups of mice underwent a buried food-pellet test to gauge olfactory function and then were nasally irrigated with 1 of 3 divalent cationic compounds. When tested after treatment, mice irrigated with zinc gluconate and copper gluconate experienced a marked increase in food-finding time, indicating that they had lost their ability to smell a hidden food source. Control mice irrigated with saline had a significantly lower increase in times. These results confirm that zinc gluconate can cause anosmia and reveal that multiple divalent cations can negatively affect olfaction. PMID:22330252

Salmonella Utilizes Zinc To Subvert Antimicrobial Host Defense of Macrophages via Modulation of NF-κB Signaling

PubMed Central

Wu, Aimin; Haschka, David; Heeke, Simon; Dichtl, Stefanie; Petzer, Verena; Seifert, Markus; Hilbe, Richard; Sopper, Sieghart; Talasz, Heribert; Bumann, Dirk; Lass-Flörl, Cornelia; Theurl, Igor; Zhang, Keying

2017-01-01

ABSTRACT Zinc sequestration by macrophages is considered a crucial host defense strategy against infection by the intracellular bacterium Salmonella enterica serovar Typhimurium. However, the underlying mechanisms remain elusive. In this study, we found that zinc favors pathogen survival within macrophages. Salmonella-hosting macrophages contained higher free zinc levels than did uninfected macrophages and cells that successfully eliminated bacteria, which was paralleled by the impaired production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in bacterium-harboring cells. A profound, zinc-mediated inhibition of NF-κB p65 transcriptional activity affecting the expression of the ROS- and RNS-forming enzymes phos47 and inducible nitric oxide synthase (iNOS) provided a mechanistic explanation for this phenomenon. Macrophages responded to infection by enhancing the expression of zinc-scavenging metallothioneins 1 and 2, whose genetic deletion caused increased free zinc levels, reduced ROS and RNS production, and increased the survival of Salmonella. Our data suggest that Salmonella invasion of macrophages results in a bacterium-driven increase in the intracellular zinc level, which weakens antimicrobial defense and the ability of macrophages to eradicate the pathogen. Thus, limitation of cytoplasmic zinc levels may help to control infection by intracellular bacteria. PMID:28874447

Zinc use efficiency is enhanced in wheat through nanofertilization.

PubMed

Dapkekar, Ashwin; Deshpande, Paresh; Oak, Manoj D; Paknikar, Kishore M; Rajwade, Jyutika M

2018-05-01

Ferti-fortification of wheat with zinc, an essential micronutrient is one of the strategies for combating 'hidden hunger' in a large proportion of people all over the world. During fertilization, application of large quantities of micronutrients often results in nutrient wastage and subsequent environmental pollution. Here, we report zinc complexed chitosan nanoparticles (Zn-CNP) for ferti-fortification of durum wheat in field-scale experiments. The efficacy of Zn-CNP was assessed vis-à-vis conventionally applied ZnSO 4 (0.2%; 400 mgL -1 zinc) in two durum wheat genotypes (MACS 3125, an indigenous high yielding genotype and UC 1114, a genotype containing the Gpc-B1gene). The observed grain zinc enrichment using Zn-CNP nanocarrier (~36%) and conventional ZnSO 4 (~50%) were comparable, despite 10 folds less zinc (40 mgL -1 ) used in the former. Nanofertilizer application increased grain zinc content without affecting grain yield, protein content, spikelets per spike, thousand kernel weight, etc. Grain zinc enrichment observed in the four-year field trials on plots with varying soil zinc content was consistent, proving the utility of Zn-CNP as a novel nanofertilizer which enhanced fertilizer use efficiency. Our work describes a new paradigm in micronutrient fortification, viz. 'use nanofertilizers at the right place, right time and in right doses'.

Passivation of Cu-Zn alloy on low carbon steel electrodeposited from a pyrophosphate medium

NASA Astrophysics Data System (ADS)

Yavuz, Abdulcabbar; Yakup Hacıibrahimoğlu, M.; Bedir, Metin

2018-01-01

The motivation of this study is to understand whether zinc-based alloy also has a passivation behaviour similar to zinc itself. Cu-Zn alloys were electrodeposited potentiostatically from a pyrophosphate medium on a carbon steel electrode and their corrosion behaviours were studied. Pt and carbon steel electrodes were used in order to examine the corrosion/passivation behaviour of bare Cu, bare Zn and Cu-Zn alloy coatings. The passivation behaviour of all brass-modified electrodes having Zn content between 10% and 100% was investigated. The growth potential affects the morphology and structure of crystals. The brass coatings are more porous than their pure components. The crystalline structure of Cu-Zn alloys can be obtained by changing the deposition potential. The zinc content in brass increases when the deposition voltage applied decreases. However, the growth potential and the ratio of zinc in brass do not affect the passivation behaviour of the resulting alloys. The coatings obtained by applying different growth potentials were immersed in tap water for 24 h to compare their corrosion behaviours with carbon steel having pitting formation.

Effects of separate delivery of zinc or zinc and vitamin A on hemoglobin response, growth, and diarrhea in young Peruvian children receiving iron therapy for anemia.

PubMed

Alarcon, Karl; Kolsteren, Patrick W; Prada, Ana M; Chian, Ana M; Velarde, Ruth E; Pecho, Iris L; Hoeree, Tom F

2004-11-01

Anemia is the most prevalent nutritional deficiency in the world. Attempts to improve iron indexes are affected by deficiency of and interaction between other micronutrients. Our goal was to assess whether zinc added to iron treatment alone or with vitamin A improves iron indexes and affects diarrheal episodes. This was a randomized, placebo-controlled, double-blind trial conducted in Peru. Anemic children aged 6-35 mo were assigned to 3 treatment groups: ferrous sulfate (FS; n = 104), ferrous sulfate and zinc sulfate (FSZn; n = 109), and ferrous sulfate, zinc sulfate, and vitamin A (FSZnA; n = 110). Vitamin A or its placebo was supplied only once; iron and zinc were provided under supervision >/=1 h apart 6 d/wk for 18 wk. The prevalence of anemia was 42.97%. The increase in hemoglobin in the FS group (19.5 g/L) was significantly less than that in the other 2 groups (24.0 and 23.8 g/L in the FSZn and FSZnA groups, respectively). The increase in serum ferritin in the FS group (24.5 mug/L) was significantly less than that in the other 2 groups (33.0 and 30.8 mug/L in the FSZn and FSZnA groups, respectively). The median duration of diarrhea and the mean number of stools per day was significantly higher in the FS group than in other 2 groups (P < 0.005). Adding zinc to iron treatment increases hemoglobin response, improves iron indexes, and has positive effects on diarrhea. No additional effect of vitamin A was found.

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate

PubMed Central

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30 μM and 100 μM of ZnCl2. Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth. PMID:29765417

Height, Zinc and Soil-Transmitted Helminth Infections in Schoolchildren: A Study in Cuba and Cambodia

PubMed Central

de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim; van der Werff, Suzanne D.; D’Haese, Patrick C.; Fiorentino, Marion; Khov, Kuong; Perignon, Marlene; Chamnan, Chhoun; Berger, Jacques; Parker, Megan E.; Junco Díaz, Raquel; Angel Núñez, Fidel; Rojas Rivero, Lázara; Bonet Gorbea, Mariano; Doak, Colleen M.; Campos Ponce, Maiza; Wieringa, Frank T.; Polman, Katja

2015-01-01

Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children, plasma zinc was associated with height for age (aB-0.033, p = 0.029), but STH infection was not. Only in Cambodia, STH infection showed an association with zinc concentration (aB-0.233, p = 0.051). Factors influencing child growth differ between populations and may depend on prevalences of STH species and zinc deficiency. Further research is needed to elucidate these relationships and their underlying mechanisms. PMID:25903454

Biomonitoring of lead-contaminated Missouri streams with an assay for erythrocyte δ-aminolevulinic acid dehydratase activity in fish blood

USGS Publications Warehouse

Schmitt, C.J.; Wildhaber, M.L.; Hunn, J.B.; Nash, T.; Tieger, M. N.; Steadman, B. L.

1993-01-01

The activity of the enzyme δ-aminolevulinic acid dehydratase (ALA-D) in erythrocytes has long been used as a biomarker of lead exposure in humans and waterfowl and, more recently, in fishes. The assay was tested for ALA-D activity in fishes from streams affected by lead in combination with other metals from lead-zinc mining and related activities. Fishes (mostly catostomids) were collected from sites affected by historic and current mining activities, and from sites considered to be unaffected by mining (reference sites). A group of potentially toxic elements was measured in blood and carcass samples of individual fish, as were ALA-D activity, total protein (TP), and hemoglobin (Hb) in blood. Concentrations of mining-related metals (lead, zinc, and cadmium) were significantly greater (P<0.05) in fish blood and carcass at sites affected by historic mining activities than at reference and active mining sites. When analyzed by multiple regression, ALA-D activity, Hb, and TP accounted for 66% of blood-lead and 69% of carcass-lead variability. Differences among species were small. ALA-D activity as a biomarker adequately distinguished sites affected by bioavailable environmental lead. Zinc was the only other metal that affected ALA-D activity; it appeared to ameliorate the inactivation of ALA-D by lead.

Cell-specific gain modulation by synaptically released zinc in cortical circuits of audition.

PubMed

Anderson, Charles T; Kumar, Manoj; Xiong, Shanshan; Tzounopoulos, Thanos

2017-09-09

In many excitatory synapses, mobile zinc is found within glutamatergic vesicles and is coreleased with glutamate. Ex vivo studies established that synaptically released (synaptic) zinc inhibits excitatory neurotransmission at lower frequencies of synaptic activity but enhances steady state synaptic responses during higher frequencies of activity. However, it remains unknown how synaptic zinc affects neuronal processing in vivo. Here, we imaged the sound-evoked neuronal activity of the primary auditory cortex in awake mice. We discovered that synaptic zinc enhanced the gain of sound-evoked responses in CaMKII-expressing principal neurons, but it reduced the gain of parvalbumin- and somatostatin-expressing interneurons. This modulation was sound intensity-dependent and, in part, NMDA receptor-independent. By establishing a previously unknown link between synaptic zinc and gain control of auditory cortical processing, our findings advance understanding about cortical synaptic mechanisms and create a new framework for approaching and interpreting the role of the auditory cortex in sound processing.

Cadmium and zinc activate adaptive mechanisms in Nicotiana tabacum similar to those observed in metal tolerant plants.

PubMed

Vera-Estrella, Rosario; Gómez-Méndez, María F; Amezcua-Romero, Julio C; Barkla, Bronwyn J; Rosas-Santiago, Paul; Pantoja, Omar

2017-09-01

Tobacco germinated and grew in the presence of high concentrations of cadmium and zinc without toxic symptoms. Evidence suggests that these ions are sequestered into the vacuole by heavy metal/H + exchanger mechanisms. Heavy metal hyperaccumulation and hypertolerance are traits shared by a small set of plants which show specialized physiological and molecular adaptations allowing them to accumulate and sequester toxic metal ions. Nicotiana tabacum was used to test its potential as a metal-accumulator in a glass house experiment. Seed germination was not affected in the presence of increasing concentrations of zinc and cadmium. Juvenile and adult plants could concentrate CdCl 2 and ZnSO 4 to levels exceeding those in the hydroponic growth medium and maintained or increased their leaf dry weight when treated with 0.5- or 1-mM CdCl 2 or 1-mM ZnSO 4 for 5 days. Accumulation of heavy metals did not affect the chlorophyll and carotenoid levels, while variable effects were observed in cell sap osmolarity. Heavy metal-dependent H + transport across the vacuole membrane was monitored using quinacrine fluorescence quenching. Cadmium- or zinc-dependent fluorescence recovery revealed that increasing concentrations of heavy metals stimulated the activities of the tonoplast Cd 2+ or Zn 2+ /H + exchangers. Immunodetection of the V-ATPase subunits showed that the increased proton transport by zinc was not due to changes in protein amount. MTP1 and MTP4 immunodetection and semiquantitative RT-PCR of NtMTP1, NtNRAMP1, and NtZIP1 helped to identify the genes that are likely involved in sequestration of cadmium and zinc in the leaf and root tissue. Finally, we demonstrated that cadmium and zinc treatments induced an accumulation of zinc in leaf tissues. This study shows that N. tabacum possesses a hyperaccumulation response, and thus could be used for phytoremediation purposes.

The zinc pool is involved in the immune-reconstituting effect of melatonin in pinealectomized mice.

PubMed

Mocchegiani, E; Bulian, D; Santarelli, L; Tibaldi, A; Muzzioli, M; Lesnikov, V; Pierpaoli, W; Fabris, N

1996-06-01

Melatonin (MEL) affects the immune system by direct or indirect mechanisms. An involvement of the zinc pool in the immune-reconstituting effect of MEL in old mice has recently been documented. An altered zinc turnover and impaired immune functions are also evident in pinealectomized (px) mice. The present work investigates further the effect of "physiological" doses of MEL on the zinc pool and on thymic and peripheral immune functions in px mice. Daily injections of MEL (100 micrograms/mouse) for 1 month in px mice restored the crude zinc balance from negative to positive values. Thymic and peripheral immune functions, including plasma levels of interleukin-2, also recovered. The nontoxic effect of MEL on immune functions was observed in sham-operated mice. Because the half-life of MEL is very short (12 min), interruption of MEL treatment in px mice resulted, after 1 month, in a renewed negative crude zinc balance and a regression of immune functions. Both the zinc pool and immunological parameters were restored by 30 further days of MEL treatment. The existence of a significant correlation between zinc and thymic hormone after both cycles of MEL treatment clearly shows an involvement of the zinc pool in the immunoenhancing effects of MEL and thus suggests an inter-relationship between zinc and MEL in px mice. Moreover, the existence of significant positive correlations between zinc or thymulin and interleukin-2 suggests that interleukin-2 may participate in the action of MEL, via zinc, on thymic functions in px MEL-treated mice.

Leptin and zinc relation: In regulation of food intake and immunity

PubMed Central

Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim

2012-01-01

Leptin is synthesized and released by the adipose tissue. Leptin, which carries the information about energy reserves of the body to the brain, controls food intake by acting on neuropeptide Y (NPY), which exercises a food-intake-increasing effect through relevant receptors in the hypothalamus. Zinc deficiency is claimed to result in anorexia, weight loss, poor food efficiency, and growth impairment. The fact that obese individuals have low zinc and high leptin levels suggests that there is a relation between zinc and nutrition, and consequently also between zinc and leptin. Leptin deficiency increases the predisposition to infections and this increase is associated with the impairments in the production of cytokines. Zinc has a key role in the sustenance of immune resistance against infections. Dietary zinc deficiency negatively affects CD+4 cells, Th functions, and consequently, cell-mediated immunity by causing a decrease in the production of IL-2, IF-γ, and TNF-α, which are Th1 products. The relation between zinc and the concerned cytokines in particular, and the fact that leptin has a part in the immune responses mediated by these cytokines demonstrate that an interaction among cellular immunity, leptin and zinc is inevitable. An overall evaluation of the information presented above suggests that there are complex relations among food intake, leptin and zinc on one hand and among cellular immunity, leptin and zinc on the other. The aim of the present review was to draw attention to the possible relation between zinc and leptin in dietary regulation and cellular immunity. PMID:23565497

Zinc deficiency in children with environmental enteropathy—development of new strategies: report from an expert workshop1234

PubMed Central

Young, Graeme P; Mortimer, Elissa K; Gopalsamy, Geetha L; Alpers, David H; Binder, Henry J; Manary, Mark J; Ramakrishna, Balakrishnan S; Brown, Ian L; Brewer, Thomas G

2014-01-01

Zinc deficiency is a major cause of childhood morbidity and mortality. The WHO/UNICEF strategy for zinc supplementation as adjunctive therapy for diarrhea is poorly implemented. A conference of experts in zinc nutrition and gastrointestinal disorders was convened to consider approaches that might complement the current recommendation and what research was needed to develop these approaches. Several key points were identified. The design of novel zinc interventions would be facilitated by a better understanding of how disturbed gut function, such as environmental (or tropical) enteropathy, affects zinc absorption, losses, and homeostasis. Because only 10% of zinc stores are able to be rapidly turned over, and appear to be rapidly depleted by acute intestinal illness, they are probably best maintained by complementary regular supplementation in a primary prevention strategy rather than secondary prevention triggered by acute diarrhea. The assessment of zinc status is challenging and complex without simple, validated measures to facilitate field testing of novel interventions. Zinc bioavailability may be a crucial factor in the success of primary prevention strategies, and a range of options, all still inadequately explored, might be valuable in improving zinc nutrition. Some therapeutic actions of zinc on diarrhea seem attributable to pharmacologic effects, whereas others are related to the reversal of deficiency (ie, nutritional). The distinction between these 2 mechanisms cannot be clarified given the insensitivity of serum zinc to identify subclinical deficiency states. Why zinc seems to be less effective than expected at all ages, and ineffective for secondary prevention of diarrhea in children <12 mo of age, remains unclear. It was concluded that a reframing of the current recommendation is warranted with consideration of how to better optimize and deliver zinc and whether to provide a complementary public health primary prevention zinc strategy. This requires careful consideration of the zinc product to be used as well as strategies for its delivery. PMID:25240082

Measuring zinc in biological nanovesicles by multiple analytical approaches.

PubMed

Piacenza, Francesco; Biesemeier, Antje; Farina, Marco; Piva, Francesco; Jin, Xin; Pavoni, Eleonora; Nisi, Lorenzo; Cardelli, Maurizio; Costarelli, Laura; Giacconi, Robertina; Basso, Andrea; Pierpaoli, Elisa; Provinciali, Mauro; Hwang, James C M; Morini, Antonio; di Donato, Andrea; Malavolta, Marco

2018-07-01

Exosomes are nanovesicles known to mediate intercellular communication. Although it is established that zinc ions can act as intracellular signaling factors, the measurement of zinc in circulating nanovesicles has not yet been attempted. Providing evidence of the existence of this zinc fraction and methods for its measurement might be important to advance our knowledge of zinc status and its relevance in diseases. Exosomes from 0.5 ml of either fresh or frozen human plasma were isolated by differential centrifugation. A morphological and dimensional evaluation at the nanoscale level was performed by atomic force microscopy (AFM) and Transmission Electron Microscopy (TEM). Energy Dispersive X-Ray Microanalysis (EDX) revealed the elemental composition of exosomes and their respective total Zinc content on a quantitative basis. The zinc mole fraction (in at%) was correlated to the phosphorous mole fraction, which is indicative for exosomal membrane material. Both fresh (Zn/P 0.09 ± 0.01) and frozen exosomes (Zn/P 0.08 ± 0.02) had a significant zinc content, which increased up to 1.09 ± 0.12 for frozen exosomes when treated with increasing amounts of zinc (100-500 μM; each p < 0.05). Interestingly, after zinc addition, the Calcium mole fractions decreased accordingly suggesting a possible exchange by zinc. In order to estimate the intra-exosomal labile zinc content, an Imaging Flow Cytometry approach was developed by using the specific membrane permeable zinc-probe Fluozin-3AM. A labile zinc content of 0.59 ± 0.27 nM was calculated but it is likely that the measurement may be affected by purification and isolation conditions. This study suggests that circulating nano-vesicular-zinc can represent a newly discovered zinc fraction in the blood plasma whose functional and biological properties will have to be further investigated in future studies. Copyright © 2018 Elsevier GmbH. All rights reserved.

SLC30A9 mutation affecting intracellular zinc homeostasis causes a novel cerebro-renal syndrome

PubMed Central

Perez, Yonatan; Shorer, Zamir; Liani-Leibson, Keren; Chabosseau, Pauline; Kadir, Rotem; Volodarsky, Michael; Halperin, Daniel; Barber-Zucker, Shiran; Shalev, Hanna; Schreiber, Ruth; Gradstein, Libe; Gurevich, Evgenia; Zarivach, Raz; Rutter, Guy A.; Landau, Daniel

2017-01-01

Abstract A novel autosomal recessive cerebro-renal syndrome was identified in consanguineous Bedouin kindred: neurological deterioration was evident as of early age, progressing into severe intellectual disability, profound ataxia, camptocormia and oculomotor apraxia. Brain MRI was normal. Four of the six affected individuals also had early-onset nephropathy with features of tubulo-interstitial nephritis, hypertension and tendency for hyperkalemia, though none had rapid deterioration of renal function. Genome wide linkage analysis identified an ∼18 Mb disease-associated locus on chromosome 4 (maximal logarithm of odds score 4.4 at D4S2971; θ = 0). Whole exome sequencing identified a single mutation in SLC30A9 within this locus, segregating as expected within the kindred and not found in a homozygous state in 300 Bedouin controls. We showed that SLC30A9 (solute carrier family 30 member 9; also known as ZnT-9) is ubiquitously expressed with high levels in cerebellum, skeletal muscle, thymus and kidney. Confocal analysis of SH-SY5Y cells overexpressing SLC30A9 fused to enhanced green fluorescent protein demonstrated vesicular cytosolic localization associated with the endoplasmic reticulum, not co-localizing with endosomal or Golgi markers. SLC30A9 encodes a putative zinc transporter (by similarity) previously associated with Wnt signalling. However, using dual-luciferase reporter assay in SH-SY5Y cells we showed that Wnt signalling was not affected by the mutation. Based on protein modelling, the identified mutation is expected to affect SLC30A9’s highly conserved cation efflux domain, putatively disrupting its transmembrane helix structure. Cytosolic Zn2+ measurements in HEK293 cells overexpressing wild-type and mutant SLC30A9 showed lower zinc concentration within mutant rather than wild-type SLC30A9 cells. This suggests that SLC30A9 has zinc transport properties affecting intracellular zinc homeostasis, and that the molecular mechanism of the disease is through defective function of this novel activity of SLC30A9 rather than by a defect in its previously described role in transcriptional activation of Wnt signalling. PMID:28334855

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial.

PubMed

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia.

Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp; Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Wada, Eiji, E-mail: gacchu1@yahoo.co.jp

2015-05-01

Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc onmore » differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.« less

Performance characteristics of zinc-rich coatings applied to carbon steel

NASA Technical Reports Server (NTRS)

Paton, W. J.

1973-01-01

A program was conducted to evaluate the performance of topcoated and untopcoated zinc-rich coatings. Sacrificial coatings of this type are required for protecting carbon steel structures from the aggressive KSC sea coast environment. A total of 59 commercially available zinc-rich coatings and 47 topcoated materials were exposed for an 18-month period. Test panels were placed in special racks placed approximately 30.5 m (100 feet) above the high tide line at the KSC Corrosion Test Site. Laboratory tests to determine the temperature resistance, abrasion resistance, and adhesion of the untopcoated zinc-rich coatings were also performed. It has been concluded that: (1) The inorganic types of zinc-rich coatings are far superior to the organic types in the KSC environment. (2) Organic zinc-rich coatings applied at 0.1 - 0.15 mm (4-6 mils) film thickness provide better corrosion protection than when applied at the manufacturers' recommended nominal film thickness of .08 mm (3 mils). (3) Topcoats are not necessary, or even desirable, when used in conjunction with zinc-rich coatings in the KSC environment. (4) Some types of inorganic zinc-rich coatings require an extended outdoor weathering period in order to obtain adequate mechanical properties. and (5) A properly formulated inorganic zinc-rich coating is not affected by a 24-hour thermal exposure to 400 C (752 F).

Effect of zinc intake on hepatic autophagy during acute alcohol intoxication.

PubMed

Liuzzi, Juan P; Narayanan, Vijaya; Doan, Huong; Yoo, Changwon

2018-04-01

Autophagy is a conserved mechanism that plays a housekeeping role by eliminating protein aggregates and damaged organelles. Recent studies have demonstrated that acute ethanol intoxication induces hepatic autophagy in mice. The effect of dietary zinc intake on hepatic autophagic flux during ethanol intoxication has not been evaluated using animal models. Herein, we investigated whether zinc deficiency and excess can affect autophagic flux in the liver in mice and in human hepatoma cells acutely exposed to ethanol. A mouse model of binge ethanol feeding was utilized to analyze the effect of low, adequate, and high zinc intake on hepatic autophagic flux during ethanol intoxication. Autophagic flux was inferred by analyzing LC3II/LC3I ratio, protein levels of p62/SQSTM1, Beclin1 and Atg7, and phosphorylation of 4EBP1. In addition, the degradation of the fusion protein LC3-GFP and the formation of autophagosomes and autolysosomes were evaluated in cells. Ethanol treatment stimulated autophagy in mice and cells. High zinc intake resulted in enhanced autophagy in mice exposed to ethanol. Conversely, zinc deficiency was consistently associated with impaired ethanol-induced autophagy in mice and cells. Zinc-deficient mice exhibited a high degree of ethanol-driven steatosis. Furthermore, zinc depletion increased apoptosis in cells exposed to ethanol. The results of this study suggest that adequate zinc intake is necessary for proper stimulation of autophagy by ethanol. Poor zinc status is commonly found among alcoholics and could likely contribute to faulty autophagy.

Zinc regulates iNOS-derived nitric oxide formation in endothelial cells.

PubMed

Cortese-Krott, Miriam M; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D; Suschek, Christoph V

2014-01-01

Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-κB transactivation activity, as determined by a decrease in both NF-κB-driven luciferase reporter activity and expression of NF-κB target genes, including cyclooxygenase 2 and IL-1β. However, zinc did not affect NF-κB translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-κB-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation.

Galvanic zinc-copper microparticles inhibit melanogenesis via multiple pigmentary pathways.

PubMed

Won, Yen-Kim; Lin, Connie B; Seiberg, Miri; Chen, Nannan; Hu, Yaping; Rossetti, Dianne; Saliou, Claude; Loy, Chong-Jin

2014-01-01

The endogenous electrical field of human skin plays an important role in many skin functions. However, the biological effects and mechanism of action of externally applied electrical stimulation on skin remain unclear. Recent study showed that galvanic zinc-copper microparticles produce electrical stimulation and reduce inflammatory and immune responses in intact skin, suggesting the important role of electrical stimulation in non-wounded skin. The objective of this study is to investigate the biological effect of galvanic zinc-copper microparticles on skin pigmentation. Our findings showed that galvanic zinc-copper microparticles inhibited melanogenesis in a human melanoma cell line (MNT-1), human keratinocytes and melanoma cells co-cultures, and in pigmented epidermal equivalents. Treatment of galvanic zinc-copper microparticles inhibited melanogenesis by reducing the promoter transactivation of tyrosinase and tyrosinase-related protein-1 in human melanoma cells. In a co-culture Transwell system of keratinocytes and melanoma cells, galvanic zinc-copper microparticles reduced melanin production via downregulation of endothelin-1 secretion from keratinocytes and reduced tyrosinase gene expression in melanoma cells. In addition, exposure of pigmented epidermal equivalents to galvanic zinc-copper microparticles resulted in reduced melanin deposition. In conclusion, our data demonstrated for the first time that galvanic zinc-copper microparticles reduced melanogenesis in melanoma cells and melanin deposition in pigmented epidermal equivalents by affecting multiple pigmentary pathways.

Effects of zinc and DHA on the epigenetic regulation of human neuronal cells.

PubMed

Sadli, Nadia; Ackland, M Leigh; De Mel, Damitha; Sinclair, Andrew J; Suphioglu, Cenk

2012-01-01

Dietary intake of zinc and omega-3 fatty acids (DHA) have health benefits for a number of human diseases. However, the molecular basis of these health benefits remains unclear. Recently, we reported that zinc and DHA affect expression levels of histones H3 and H4 in human neuronal M17 cells. Here, using immunoblotting and densitometric analysis, we aimed to investigate the effect of zinc and DHA on post-translational modifications of histone H3 in M17 cells. In response to increase in zinc concentration, we observed increase in deacetylation, methylation and phosphorylation of H3 and decrease in acetylation. We also investigated the role of zinc in apoptosis, and found that zinc reduced the levels of the anti-apoptotic marker Bcl-2 while increasing the apoptotic marker caspase-3 levels, correlating with cell viability assays. Conversely, DHA treatment resulted in increase in acetylation of H3 and Bcl-2 levels and decrease in deacetylation, methylation, phosphorylation of H3 and caspase-3 levels, suggesting that DHA promotes gene expression and neuroprotection. Our novel findings show the opposing effects of zinc and DHA on the epigenetic regulation of human neuronal cells and highlight the potential benefit of dietary intake of DHA for management of neurodegenerative diseases. Copyright © 2012 S. Karger AG, Basel.

Zinc regulates iNOS-derived nitric oxide formation in endothelial cells

PubMed Central

Cortese-Krott, Miriam M.; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D.; Suschek, Christoph V.

2014-01-01

Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-κB transactivation activity, as determined by a decrease in both NF-κB-driven luciferase reporter activity and expression of NF-κB target genes, including cyclooxygenase 2 and IL-1β. However, zinc did not affect NF-κB translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-κB-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation. PMID:25180171

Clioquinol-zinc chelate: a candidate causative agent of subacute myelo-optic neuropathy.

PubMed Central

Arbiser, J. L.; Kraeft, S. K.; van Leeuwen, R.; Hurwitz, S. J.; Selig, M.; Dickersin, G. R.; Flint, A.; Byers, H. R.; Chen, L. B.

1998-01-01

BACKGROUND: 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol) was used clinically three decades ago as an oral antiparasitic agent and to increase intestinal absorption of zinc in patients with acrodermatitis enteropathica, a genetic disorder of zinc absorption. Use of clioquinol was epidemiologically linked to subacute myelo-optic neuropathy (SMON), characterized by peripheral neuropathy and blindness, which affected 10,000 patients in Japan. Discontinuation of oral clioquinol use led to elimination of SMON, however, the mechanism of how clioquinol induces neurotoxicity is unclear. MATERIALS AND METHODS: We tested the effect of clioquinol-metal chelates on neural crest-derived melanoma cells. The effect of clioquinol chelates on cells was further studied by electron microscopy and by a mitochondrial potential-sensitive fluorescent dye. RESULTS: Of the ions tested, only clioquinol-zinc chelate demonstrated cytotoxicity. The cytotoxicity of clioquinol-zinc chelate was extremely rapid, suggesting that its primary effect was on the mitochondria. Electron microscopic analysis demonstrated that clioquinol-zinc chelate caused mitochondrial damage. This finding was further confirmed by the observation that clioquinol-zinc chelate caused a decrease in mitochondrial membrane potential. CONCLUSIONS: We demonstrate that clioquinol, in the presence of zinc, is converted to a potent mitochondrial toxin. The phenomenon of clioquinol mediated toxicity appears to be specific to zinc and is not seen with other metals tested. Since clioquinol has been shown to cause increased systemic absorption of zinc in humans, it is likely that clioquinol-zinc chelate was present in appreciable levels in patients with SMON and may be the ultimate causative toxin of SMON. Images Fig. 2 Fig. 3 PMID:9848083

Zinc enhances the number of regulatory T cells in allergen-stimulated cells from atopic subjects.

PubMed

Rosenkranz, Eva; Hilgers, Ralf-Dieter; Uciechowski, Peter; Petersen, Arnd; Plümäkers, Birgit; Rink, Lothar

2017-03-01

The trace element zinc is essential for immune function and its regulation. Since zinc deficiency and allergic hyperresponsive reactions are often accompanied, the influence of zinc on allergen-induced cell growth, CD4+ regulatory T (Treg) cell numbers and cytokine expression during allergic immune reactions was investigated. Peripheral blood mononuclear cells (PBMCs) from non-atopic and atopic subjects were treated with timothy grass allergen pre-incubated with or without zinc. Proliferation was determined by analyzing the incorporation of 3 H-thymidine. Intracellular zinc and Foxp3 levels and cell surface antigens were measured by FACS, cytokine expression by ELISA and real-time PCR. Incubation with 50 μM zinc sulfate (Zn50) enhances cytosolic zinc concentrations in CD3+ T cells. The data also reveal that the combination of Zn50 plus allergen significantly reduces PBMC proliferation of atopic subjects. Additionally, Zn50 plus allergen enhances Th1 cytokine responses shown by increased interferon (IFN)-γ/interleukin (IL)-10 ratios as well as enhanced tumor necrosis factor-α release. In response to allergen, zinc increases Treg cells and upregulates the mRNA expression of cytotoxic T-lymphocyte antigen-4 in atopic subjects. Interestingly, Zn50 alone leads to an increase of CD4+CD25high(hi)+ cells in atopic and non-atopic subjects. Zinc may regulate unwanted hyperresponsive immune reactions by suppressing proliferation through a significant shift from IL-10 to the Th1 cytokine IFN-γ, and enhanced regulatory T cell numbers. Therefore, zinc supplementation may be a promising tool for the therapy of allergies, without negatively affecting the immune system.

A multilateral investigation of the effects of zinc level on pregnancy.

PubMed

Özgan Çelikel, Özgül; Doğan, Özlem; Aksoy, Nurkan

2018-06-01

The relationship between maternal zinc level and birth weight, birth week, delivery type, garvida, maternal age, etc., contribute to diagnosis and clinical follow-up. Multivariate investigated for data of 275 patients were obtained during their pregnancy periods until birth. 3 cc blood samples were centrifuged for 15 minutes at 2500 g within a period of 30 minutes and were stored at -80°C until the time of analysis. The zinc levels of the patients were found to be within the range of 49-129 μg/dL. Patients were divided into 8 groups according to their zinc levels (49-59, 60-69, …, 120-129) and the relationships of zinc level with the parameters related to the mode of delivery, week of delivery, birth weight, age, early membrane rupture, live-stillbirth, and gravid were statistically analyzed to determine differences between the groups. There was a significant difference between the live births and stillbirths with a 95% confidence level regarding the zinc level. The zinc level affected the live-stillbirth status; patients with a zinc level of 49-59 μg/dL had stillbirths, the live birth rate for 59-69 μg/dL was approximately 50%, whereas it was approximately 88% for in the patients with a zinc level of 109-119 μg/dL. All patients with a zinc level of 119 μg/dL and above had live births. Based on the results of this study, it is suggested that zinc supplementation may be an appropriate treatment for the pregnant women with low zinc levels to provide the realization of live births. © 2018 Wiley Periodicals, Inc.

Effects of zinc and cholesterol/choleate on serum lipoproteins and the liver in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, C.H.; Chen, S.M.; Ogle, C.W.

1989-01-01

The effects of short-term treatment with orally-administered zinc sulfate and/or a mixture of cholesterol/choleate on serum lipoprotein and hepatic enzyme levels were studied. Administration of graded doses of zinc sulfate for 5 days, dose-dependently increased serum and hepatic zinc levels but depressed the serum high-density lipoprotein-cholesterol (HDL-C) concentration and liver cytochrome P-450 activity. However, it did not affect hepatic concentrations of malondialdehyde and free {beta}-glucuronidase. Cholesterol/choleate treatment for 5 days markedly damaged the liver, as reflected by elevations of hepatic concentrations of malondialdehyde (both in the mitochondrial and microsomal fractions) and of free {beta}-glucuronidase; total cholesterol and low-density lipoprotein-cholesterol inmore » the blood were increased, whereas HDL-C was decreased significantly. Concomitant administration of zinc sulfate with cholesterol/choleate further lowered HDL-C levels, but reversed the high hepatic concentrations of both malondialdehyde and free {beta}-glucuronidase. The present study indicates that both zinc ions and cholesterol can decrease circulatory HDL-C levels and that zinc protects against cholesterol-induced hepatic damage by reducing lysosomal enzyme release and preventing lipid peroxidation in the liver.« less

Real-time monitoring of laser welding of galvanized high strength steel in lap joint configuration

NASA Astrophysics Data System (ADS)

Kong, Fanrong; Ma, Junjie; Carlson, Blair; Kovacevic, Radovan

2012-10-01

Two different cases regarding the zinc coating at the lap joint faying surface are selected for studying the influence of zinc vapor on the keyhole dynamics of the weld pool and the final welding quality. One case has the zinc coating fully removed at the faying surface; while the other case retains the zinc coating on the faying surface. It is found that removal of the zinc coating at the faying surface produces a significantly better weld quality as exemplified by a lack of spatters whereas intense spatters are present when the zinc coating is present at the faying surface. Spectroscopy is used to detect the optical spectra emitted from a laser generated plasma plume during the laser welding of galvanized high strength DP980 steel in a lap-joint configuration. A correlation between the electron temperature and defects within the weld bead is identified by using the Boltzmann plot method. The laser weld pool keyhole dynamic behavior affected by a high-pressure zinc vapor generated at the faying surface of galvanized steel lap-joint is monitored in real-time by a high speed charge-coupled device (CCD) camera assisted with a green laser as an illumination source.

X-ray tomography as a powerful method for zinc-air battery research

NASA Astrophysics Data System (ADS)

Franke-Lang, Robert; Arlt, Tobias; Manke, Ingo; Kowal, Julia

2017-12-01

X-ray tomography is used to investigate material redistribution and effects of electrochemical reactions in a zinc-air battery in-situ. For this, a special battery set-up is developed which meets tomographic and electrochemical requirements. The prepared batteries are discharged and some of them have partially been charged. To analyse the three-dimensional structure of the zinc and air electrode a tomographic measurement is made in charge and discharge condition without disassembling the battery. X-ray tomography gives the opportunity to detect and analyse three different effects within the cell operation: tracking the morphology and transformation of zinc and air electrode, monitoring electrolyte decomposition and movement, finding electrical misbehaviour by parasitic reactions. Therefore, it is possible to identify the loss of capacity and major problems of cyclability. The electrolyte strongly reacts with the pure zinc that leads to gassing and a loss of electrolyte. The loss prevents a charge carrier exchange between the anode and the cathode and reduces the theoretical capacity. One of the chemical reaction produces hydroxylated zinc, namely zincate. The most crucial problems with cyclability are affected by zincate movement into the catalyst layer. This assumption is confirmed by finding pure zinc areas within the catalyst layer.

Zinc attenuates forskolin-stimulated electrolyte secretion without involvement of the enteric nervous system in small intestinal epithelium from weaned piglets.

PubMed

Feng, Zike; Carlson, Dorthe; Poulsen, Hanne Damgaard

2006-11-01

In a previous study, we found that secretagogue-stimulated electrolyte secretion was attenuated by dietary and serosal zinc in piglet small intestinal epithelium in Ussing chambers. Several studies show that the enteric nervous system (ENS) is involved in regulation of electrolyte and/or fluid transport in intestinal epithelium from many species. The aim of the present study is to examine the mechanisms behind the attenuating effect of zinc on electrolyte secretion and to study whether the ENS is involved in this effect of zinc in vitro. Twenty-four piglets (six litters of four piglets) were allocated randomly to one of two dietary treatments consisting of a basic diet supplemented with 100 mg zinc/kg (Zn(100)) or 2500 mg zinc/kg (Zn(2500)), as ZnO. All the piglets were killed at 5-6 days after weaning and in vitro experiments with small intestinal epithelium in Ussing chambers were carried out. Furthermore, zinc, copper, alkaline phosphatase (AP) and metallothionein (MT) in mucosa, liver, and plasma were measured. These measurements showed that zinc status was increased in the Zn(2500) compared to the Zn(100) fed piglets. The in vitro studies did not confirm previous findings of attenuating effects of dietary zinc and zinc in vitro on the 5-HT induced secretion. But it showed that the addition of zinc at the serosal side attenuated the forskolin (FSK) (cAMP-dependent) induced ion secretion in epithelium from piglets fed with Zn(100) diet. Blocking the ENS with lidocaine or hexamethonium apparently slightly reduced this effect of zinc in vitro, but did not remove the effect of zinc. Consequently, it is suggested that zinc attenuates the cAMP dependent ion secretion mainly due to an effect on epithelial cells rather than affecting the mucosal neuronal pathway.

Requirement of Zinc Transporter SLC39A7/ZIP7 for Dermal Development to Fine-Tune Endoplasmic Reticulum Function by Regulating Protein Disulfide Isomerase.

PubMed

Bin, Bum-Ho; Bhin, Jinhyuk; Seo, Juyeon; Kim, Se-Young; Lee, Eunyoung; Park, Kyuhee; Choi, Dong-Hwa; Takagishi, Teruhisa; Hara, Takafumi; Hwang, Daehee; Koseki, Haruhiko; Asada, Yoshinobu; Shimoda, Shinji; Mishima, Kenji; Fukada, Toshiyuki

2017-08-01

Skin is the first area that manifests zinc deficiency. However, the molecular mechanisms by which zinc homeostasis affects skin development remain largely unknown. Here, we show that zinc-regulation transporter-/iron-regulation transporter-like protein 7 (ZIP7) localized to the endoplasmic reticulum plays critical roles in connective tissue development. Mice lacking the Slc39a7/Zip7 gene in collagen 1-expressing tissue exhibited dermal dysplasia. Ablation of ZIP7 in mesenchymal stem cells inhibited cell proliferation thereby preventing proper dermis formation, indicating that ZIP7 is required for dermal development. We also found that mesenchymal stem cells lacking ZIP7 accumulated zinc in the endoplasmic reticulum, which triggered zinc-dependent aggregation and inhibition of protein disulfide isomerase, leading to endoplasmic reticulum dysfunction. These results suggest that ZIP7 is necessary for endoplasmic reticulum function in mesenchymal stem cells and, as such, is essential for dermal development. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Wurtzite/zinc-blende electronic-band alignment in basal-plane stacking faults in semi-polar GaN

NASA Astrophysics Data System (ADS)

Monavarian, Morteza; Hafiz, Shopan; Izyumskaya, Natalia; Das, Saikat; Özgür, Ümit; Morkoç, Hadis; Avrutin, Vitaliy

2016-02-01

Heteroepitaxial semipolar and nonpolar GaN layers often suffer from high densities of extended defects including basal plane stacking faults (BSFs). BSFs which are considered as inclusions of cubic zinc-blende phase in wurtzite matrix act as quantum wells strongly affecting device performance. Band alignment in BSFs has been discussed as type of band alignment at the wurtzite/zinc blende interface governs the response in differential transmission; fast decay after the pulse followed by slow recovery due to spatial splitting of electrons and heavy holes for type- II band alignment in contrast to decay with no recovery in case of type I band alignment. Based on the results, band alignment is demonstrated to be of type II in zinc-blende segments in wurtzite matrix as in BSFs.

Potential ecological risk assessment and predicting zinc accumulation in soils.

PubMed

Baran, Agnieszka; Wieczorek, Jerzy; Mazurek, Ryszard; Urbański, Krzysztof; Klimkowicz-Pawlas, Agnieszka

2018-02-01

The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and intensity of industrial development. The zinc content was affected by soil factors, and the type of land use (arable lands, grasslands, forests, wastelands). A total of 320 soil samples were characterized in terms of physicochemical properties (texture, pH, organic C content, total and available Zn content). Based on the obtained data, assessment of the ecological risk of zinc was conducted using two methods: potential ecological risk index and hazard quotient. Total Zn content in the soils ranged from 8.27 to 7221 mg kg -1 d.m. Based on the surface semivariograms, the highest variability of zinc in the soils was observed from northwest to southeast. The point sources of Zn contamination were located in the northwestern part of the area, near the mining-metallurgical activity involving processing of zinc and lead ores. These findings were confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. The content of bioavailable forms of zinc was between 0.05 and 46.19 mg kg -1 d.m. (0.01 mol dm -3 CaCl 2 ), and between 0.03 and 71.54 mg kg -1 d.m. (1 mol dm -3 NH 4 NO 3 ). Forest soils had the highest zinc solubility, followed by arable land, grassland and wasteland. PCA showed that organic C was the key factor to control bioavailability of zinc in the soils. The extreme, very high and medium zinc accumulation was found in 69% of studied soils. There is no ecological risk of zinc to living organisms in the study area, and in 90% of the soils there were no potentially negative effects of zinc to ecological receptors.

Genetic Variability, Genotype × Environment Interaction, Correlation, and GGE Biplot Analysis for Grain Iron and Zinc Concentration and Other Agronomic Traits in RIL Population of Sorghum (Sorghum bicolor L. Moench)

PubMed Central

Phuke, Rahul M.; Anuradha, Kotla; Radhika, Kommineni; Jabeen, Farzana; Anuradha, Ghanta; Ramesh, Thatikunta; Hariprasanna, K.; Mehtre, Shivaji P.; Deshpande, Santosh P.; Anil, Gaddameedi; Das, Roma R.; Rathore, Abhishek; Hash, Tom; Reddy, Belum V. S.; Kumar, Are Ashok

2017-01-01

The low grain iron and zinc densities are well documented problems in food crops, affecting crop nutritional quality especially in cereals. Sorghum is a major source of energy and micronutrients for majority of population in Africa and central India. Understanding genetic variation, genotype × environment interaction and association between these traits is critical for development of improved cultivars with high iron and zinc. A total of 336 sorghum RILs (Recombinant Inbred Lines) were evaluated for grain iron and zinc concentration along with other agronomic traits for 2 years at three locations. The results showed that large variability exists in RIL population for both micronutrients (Iron = 10.8 to 76.4 mg kg−1 and Zinc = 10.2 to 58.7 mg kg−1, across environments) and agronomic traits. Genotype × environment interaction for both micronutrients (iron and zinc) was highly significant. GGE biplots comparison for grain iron and zinc showed greater variation across environments. The results also showed that G × E was substantial for grain iron and zinc, hence wider testing needed for taking care of G × E interaction to breed micronutrient rich sorghum lines. Iron and zinc concentration showed high significant positive correlation (across environment = 0.79; p < 0.01) indicating possibility of simultaneous effective selection for both the traits. The RIL population showed good variability and high heritabilities (>0.60, in individual environments) for Fe and Zn and other traits studied indicating its suitability to map QTL for iron and zinc. PMID:28529518

The structural role of the zinc ion can be dispensable in prokaryotic zinc-finger domains

PubMed Central

Baglivo, Ilaria; Russo, Luigi; Esposito, Sabrina; Malgieri, Gaetano; Renda, Mario; Salluzzo, Antonio; Di Blasio, Benedetto; Isernia, Carla; Fattorusso, Roberto; Pedone, Paolo V.

2009-01-01

The recent characterization of the prokaryotic Cys2His2 zinc-finger domain, identified in Ros protein from Agrobacterium tumefaciens, has demonstrated that, although possessing a similar zinc coordination sphere, this domain is structurally very different from its eukaryotic counterpart. A search in the databases has identified ≈300 homologues with a high sequence identity to the Ros protein, including the amino acids that form the extensive hydrophobic core in Ros. Surprisingly, the Cys2His2 zinc coordination sphere is generally poorly conserved in the Ros homologues, raising the question of whether the zinc ion is always preserved in these proteins. Here, we present a functional and structural study of a point mutant of Ros protein, Ros56–142C82D, in which the second coordinating cysteine is replaced by an aspartate, 5 previously-uncharacterized representative Ros homologues from Mesorhizobium loti, and 2 mutants of the homologues. Our results indicate that the prokaryotic zinc-finger domain, which in Ros protein tetrahedrally coordinates Zn(II) through the typical Cys2His2 coordination, in Ros homologues can either exploit a CysAspHis2 coordination sphere, previously never described in DNA binding zinc finger domains to our knowledge, or lose the metal, while still preserving the DNA-binding activity. We demonstrate that this class of prokaryotic zinc-finger domains is structurally very adaptable, and surprisingly single mutations can transform a zinc-binding domain into a nonzinc-binding domain and vice versa, without affecting the DNA-binding ability. In light of our findings an evolutionary link between the prokaryotic and eukaryotic zinc-finger domains, based on bacteria-to-eukaryota horizontal gene transfer, is discussed. PMID:19369210

Interdependence of free zinc changes and protein complex assembly - insights into zinc signal regulation.

PubMed

Kocyła, Anna; Adamczyk, Justyna; Krężel, Artur

2018-01-24

Cellular zinc (Zn(ii)) is bound with proteins that are part of the proteomes of all domains of life. It is mostly utilized as a catalytic or structural protein cofactor, which results in a vast number of binding architectures. The Zn(ii) ion is also important for the formation of transient protein complexes with a Zn(ii)-dependent quaternary structure that is formed upon cellular zinc signals. The mechanisms by which proteins associate with and dissociate from Zn(ii) and the connection with cellular Zn(ii) changes remain incompletely understood. In this study, we aimed to examine how zinc protein domains with various Zn(ii)-binding architectures are formed under free Zn(ii) concentration changes and how formation of the Zn(ii)-dependent assemblies is related to the protein concentration and reactivity. To accomplish these goals we chose four zinc domains with different Zn(ii)-to-protein binding stoichiometries: classical zinc finger (ZnP), LIM domain (Zn 2 P), zinc hook (ZnP 2 ) and zinc clasp (ZnP 1 P 2 ) folds. Our research demonstrated a lack of changes in the saturation level of intraprotein zinc binding sites, despite various peptide concentrations, while homo- and heterodimers indicated a concentration-dependent tendency. In other words, at a certain free Zn(ii) concentration, the fraction of a formed dimeric complex increases or decreases with subunit concentration changes. Secondly, even small or local changes in free Zn(ii) may significantly affect protein saturation depending on its architecture, function and subcellular concentration. In our paper, we indicate the importance of interdependence of free Zn(ii) availability and protein subunit concentrations for cellular zinc signal regulation.

Zinc transport by respiratory epithelial cells and interaction with iron homeostasis.

PubMed

Deng, Zhongping; Dailey, Lisa A; Soukup, Joleen; Stonehuerner, Jacqueline; Richards, Judy D; Callaghan, Kimberly D; Yang, Funmei; Ghio, Andrew J

2009-10-01

Despite recurrent exposure to zinc through inhalation of ambient air pollution particles, relatively little information is known about the homeostasis of this metal in respiratory epithelial cells. We describe zinc uptake and release by respiratory epithelial cells and test the postulate that Zn(2+) transport interacts with iron homeostasis in these same cells. Zn(2+) uptake after 4 and 8 h of exposure to zinc sulfate was concentration- and time-dependent. A majority of Zn(2+) release occurred in the 4 h immediately following cell exposure to ZnSO(4). Regarding metal importers, mRNA for Zip1 and Zip2 showed no change after respiratory epithelial cell exposure to zinc while mRNA for divalent metal transporter (DMT)1 increased. Western blot assay for DMT1 protein supported an elevated expression of this transport protein following zinc exposure. RT-PCR confirmed mRNA for the metal exporters ZnT1 and ZnT4 with the former increasing after ZnSO(4). Cell concentrations of ferritin increased with zinc exposure while oxidative stress, measured as lipid peroxides, was decreased supporting an anti-oxidant function for Zn(2+). Increased DMT1 expression, following pre-incubations of respiratory epithelial cells with TNF-alpha, IFN-gamma, and endotoxin, was associated with significantly decreased intracellular zinc transport. Finally, incubations of respiratory epithelial cells with both zinc sulfate and ferric ammonium citrate resulted in elevated intracellular concentrations of both metals. We conclude that exposure to zinc increases iron uptake by respiratory epithelial cells. Elevations in cell iron can possibly affect an increased expression of DMT1 and ferritin which function to diminish oxidative stress. Comparable to other metal exposures, changes in iron homeostasis may contribute to the biological effects of zinc in specific cells and tissues.

The zinc dyshomeostasis hypothesis of Alzheimer's disease.

PubMed

Craddock, Travis J A; Tuszynski, Jack A; Chopra, Deepak; Casey, Noel; Goldstein, Lee E; Hameroff, Stuart R; Tanzi, Rudolph E

2012-01-01

Alzheimer's disease (AD) is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ), intracellular neurofibrillary tangles (NFTs) composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau), and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques) not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1) used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2) performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3) used metallomic imaging mass spectrometry (MIMS) to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of polymerized microtubules, their binding to MAP-tau, and molecular dynamics involved in cognition. Further, our theory supports novel AD therapeutic strategies targeting intra-neuronal zinc homeostasis and microtubule dynamics to prevent neurodegeneration and cognitive decline.

Zinc Replenishment Reverses Overexpression of the Proinflammatory Mediator S100A8 and Esophageal Preneoplasia in the Rat

PubMed Central

Taccioli, Cristian; Wan, Shao-Gui; Liu, Chang-Gong; Alder, Hansjuerg; Volinia, Stefano; Farber, John L.; Croce, Carlo M.

2009-01-01

Background & Aims Zinc-deficiency is implicated in the pathogenesis of human esophageal cancer. In the rat esophagus, it induces cell proliferation, modulates genetic expression, and enhances carcinogenesis. Zinc-replenishment reverses proliferation and inhibits carcinogenesis. The zinc-deficient rat model allows the identification of biological differences affected by zinc during early esophageal carcinogenesis. Methods We evaluated gene expression profiles of esophageal epithelia from zinc-deficient and replenished rats versus sufficient rats using Affymetrix Rat Genome GeneChip. We characterized the role of the top-upregulated gene S100A8 in esophageal hyperplasia/reversal and in chemically-induced esophageal carcinogenesis in zinc-modulated animals by immunohistochemistry and real-time quantitative polymerase chain reaction. Results The hyperplastic deficient esophagus has a distinct expression signature with the proinflammation-gene S100A8 and S100A9 upregulated 57- and 5-fold. “Response to external stimulus” comprising S100A8 was the only significantly overrepresented biological pathway among the upregulated genes. Zinc-replenishment rapidly restored to control levels the expression of S100A8/A9 and 27 other genes and reversed the hyperplastic phenotype. With its receptor RAGE, co-localization and overexpression of S100A8 protein occurred in the deficient esophagus that overexpressed NF-κB p65 and COX-2 protein. Zinc-replenishment but not by a COX-2 inhibitor reduced the overexpression of these 4 proteins. Additionally, esophageal S100A8/A9 mRNA levels were directly associated with the diverse tumorigenic outcome in zinc-deficient and zinc-replenished rats. Conclusions In vivo zinc regulates S100A8 expression and modulates the link between S100A8-RAGE interaction and downstream NF-κB/COX-2 signaling. The finding that zinc regulates an inflammatory pathway in esophageal carcinogenesis may lead to prevention and therapy for this cancer. PMID:19111725

Metamorphosis affects metal concentrations and isotopic signatures in a mayfly (Baetis tricaudatus): Implications for the aquatic-terrestrial transfer of metals

USGS Publications Warehouse

Wesner, Jeff S.; Walters, David; Schmidt, Travis S.; Kraus, Johanna M.; Stricker, Craig A.; Clements, William H.; Wolf, Ruth E.

2017-01-01

Insect metamorphosis often results in substantial chemical changes that can alter contaminant concentrations and fractionate isotopes. We exposed larval mayflies (Baetis tricaudatus) and their food (periphyton) to an aqueous zinc gradient (3-340 µg Zn/l) and measured zinc concentrations at different stages of metamorphosis: larval, subimago, and imago. We also measured changes in stable isotopes (δ15N and δ13C) in unexposed mayflies. Larval zinc concentrations were positively related to aqueous zinc, increasing 9-fold across the exposure gradient. Adult zinc concentrations were also positively related to aqueous zinc, but were 7-fold lower than larvae. This relationship varied according to adult substage and sex. Tissue concentrations in female imagoes were not related to exposure concentrations, but the converse was true for all other stage-by-sex combinations. Metamorphosis also increased δ15N by ~0.8‰, but not δ13C. Thus, the main effects of metamorphosis on insect chemistry were large declines in zinc concentrations coupled with increased δ15N signatures. For zinc, this change was largely consistent across the aqueous exposure gradient. However, differences among sexes and stages suggest that caution is warranted when using nitrogen isotopes or metal concentrations measured in one insect stage (e.g. larvae) to assess risk to wildlife that feed on subsequent life stages (e.g. adults).

Metamorphosis Affects Metal Concentrations and Isotopic Signatures in a Mayfly (Baetis tricaudatus): Implications for the Aquatic-Terrestrial Transfer of Metals.

PubMed

Wesner, Jeff S; Walters, David M; Schmidt, Travis S; Kraus, Johanna M; Stricker, Craig A; Clements, William H; Wolf, Ruth E

2017-02-21

Insect metamorphosis often results in substantial chemical changes that can alter contaminant concentrations and fractionate isotopes. We exposed larval mayflies (Baetis tricaudatus) and their food (periphyton) to an aqueous zinc gradient (3-340 μg Zn/l) and measured zinc concentrations at different stages of metamorphosis: larval, subimago, and imago. We also measured changes in stable isotopes (δ 15 N and δ 13 C) in unexposed mayflies. Larval zinc concentrations were positively related to aqueous zinc, increasing 9-fold across the exposure gradient. Adult zinc concentrations were also positively related to aqueous zinc, but were 7-fold lower than larvae. This relationship varied according to adult substage and sex. Tissue concentrations in female imagoes were not related to exposure concentrations, but the converse was true for all other stage-by-sex combinations. Metamorphosis also increased δ 15 N by ∼0.8‰, but not δ 13 C. Thus, the main effects of metamorphosis on insect chemistry were large declines in zinc concentrations coupled with increased δ 15 N signatures. For zinc, this change was largely consistent across the aqueous exposure gradient. However, differences among sexes and stages suggest that caution is warranted when using nitrogen isotopes or metal concentrations measured in one insect stage (e.g., larvae) to assess risk to wildlife that feed on subsequent life stages (e.g., adults).

Influence of zinc deficiency on cell-membrane fluidity in Jurkat, 3T3 and IMR-32 cells.

PubMed Central

Verstraeten, Sandra V; Zago, M Paola; MacKenzie, Gerardo G; Keen, Carl L; Oteiza, Patricia I

2004-01-01

We investigated whether zinc deficiency can affect plasma membrane rheology. Three cell lines, human leukaemia T-cells (Jurkat), rat fibroblasts (3T3) and human neuroblastoma cells (IMR-32), were cultured for 48 h in control medium, in zinc-deficient medium (1.5 microM zinc; 1.5 Zn), or in the zinc-deficient medium supplemented with 15 microM zinc (15 Zn). The number of viable cells was lower in the 1.5 Zn group than in the control and 15 Zn groups. The frequency of apoptosis was higher in the 1.5 Zn group than in the control and 15 Zn groups. Membrane fluidity was evaluated using the 6-(9-anthroyloxy)stearic acid and 16-(9-anthroyloxy)palmitic acid probes. Membrane fluidity was higher in 1.5 Zn cells than in the control cells; no differences were observed between control cells and 15 Zn cells. The effect of zinc deficiency on membrane fluidity at the water/lipid interface was associated with a higher phosphatidylserine externalization. The higher membrane fluidity in the hydrophobic region of the bilayer was correlated with a lower content of arachidonic acid. We suggest that the increased fluidity of the membrane secondary to zinc deficiency is in part due to a decrease in arachidonic acid content and the apoptosis-related changes in phosphatidylserine distribution. PMID:14629198

Role of zinc in maternal and child mental health1234

PubMed Central

Ramirez-Zea, Manuel

2009-01-01

Mental health problems in women, children, and adolescents are a significant public health issue. Given current barriers to the effective treatment of these problems, researchers are looking to the field of nutrition for potential alternatives to better understand and address mental health issues. The purpose of this article was to review current evidence on the relation between zinc and mental health disorders with a focus on 2 mental health problems that commonly affect women and children: depression and attention-deficit hyperactivity disorder (ADHD). A literature search of the databases Medline and PsychInfo was conducted with the use of key terms. The review included articles from 1975 to May 2008, but focused on articles published in recent years. Relations between zinc concentrations and behavior in animals; the relation between zinc deficiency, depression, and ADHD in patient and community samples; and the potential biological mechanisms for these relations were explored. The data support a relation between low concentrations of zinc and mental health problems, especially in at-risk populations. Evidence for the potential use of zinc in treating mental health problems comes mainly from patient populations and is strongest when zinc is given in combination with pharmacologic treatment. Less conclusive evidence exists for the effectiveness of zinc alone or in general community samples. Recommendations for further research in this area are provided. PMID:19176735

Impact of Cadmium on Intracellular Zinc Levels in HepG2 Cells: Quantitative Evaluations and Molecular Effects.

PubMed

Urani, Chiara; Melchioretto, Pasquale; Bruschi, Maurizio; Fabbri, Marco; Sacco, Maria Grazia; Gribaldo, Laura

2015-01-01

Cadmium is classified as a human carcinogen, and its disturbance in zinc homeostasis has been well established. However, its extent as well as molecular mechanisms involved in cadmium carcinogenesis has yet to be fully clarified. To this end, we used the zinc specific probe Zinquin to visualize and to quantitatively evaluate changes in the concentration of labile zinc, in an in vitro model of human hepatic cells (HepG2) exposed to cadmium. A very large increase (+93%) of intracellular labile zinc, displaced by cadmium from the zinc proteome, was measured when HepG2 were exposed to 10 µM cadmium for 24 hrs. Microarray expression profiling showed that in cells, featuring an increase of labile zinc after cadmium exposure, one of the top regulated genes is Snail1 (+3.6), which is included in the adherens junction pathway and linked to cancer. In the same pathway MET, TGF-βR, and two members of the Rho-family GTPase, Rac, and cdc42 all implicated in the loss of adherence features and acquisition of migratory and cancer properties were regulated, as well. The microRNAs analysis showed a downregulation of miR-34a and miR-200a, both implicated in the epithelial-mesenchymal transition. These microRNAs results support the role played by zinc in affecting gene expression at the posttranscriptional level.

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial

PubMed Central

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

Objectives: This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. Methods: This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Results: Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Conclusion: Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia. PMID:25674110

Mechanisms of Zn(II) binded to collagen and its effect on the capacity of eco-friendly Zn-Cr combination tanning system.

PubMed

Cao, Shan; Liu, Bing; Cheng, Baozhen; Lu, Fuping; Wang, Yanping; Li, Yu

2017-01-05

The eco-friendly combination tanning process has been developed to reduce chromium in existing researches, which is based on zinc tanning agents. This can be considered as a less-chrome substitute for current tanning process. To gain deeper understanding of the binding mechanisms of zinc-collagen interaction, which are affected by tanning pH, experiments have been carried out. Analysis in this paper reveals how chemical bonds from the collagen's main function groups combine with zinc. XPS and NIR data was analyzed for further understanding of where the zinc binding sites lie on collagen fibers at different pH. The results indicate that high pH is helpful to amino-binding sites while low pH promotes carboxyl-binding sites on collagen fibers. Furthermore, from the effect of Zinc-chrome combination tanning, we can see that the new method reduces the chromium dosage in tanning process compared to the conventional chrome tanning method. Copyright © 2016 Elsevier B.V. All rights reserved.

SLC30A9 mutation affecting intracellular zinc homeostasis causes a novel cerebro-renal syndrome.

PubMed

Perez, Yonatan; Shorer, Zamir; Liani-Leibson, Keren; Chabosseau, Pauline; Kadir, Rotem; Volodarsky, Michael; Halperin, Daniel; Barber-Zucker, Shiran; Shalev, Hanna; Schreiber, Ruth; Gradstein, Libe; Gurevich, Evgenia; Zarivach, Raz; Rutter, Guy A; Landau, Daniel; Birk, Ohad S

2017-04-01

A novel autosomal recessive cerebro-renal syndrome was identified in consanguineous Bedouin kindred: neurological deterioration was evident as of early age, progressing into severe intellectual disability, profound ataxia, camptocormia and oculomotor apraxia. Brain MRI was normal. Four of the six affected individuals also had early-onset nephropathy with features of tubulo-interstitial nephritis, hypertension and tendency for hyperkalemia, though none had rapid deterioration of renal function. Genome wide linkage analysis identified an ∼18 Mb disease-associated locus on chromosome 4 (maximal logarithm of odds score 4.4 at D4S2971; θ = 0). Whole exome sequencing identified a single mutation in SLC30A9 within this locus, segregating as expected within the kindred and not found in a homozygous state in 300 Bedouin controls. We showed that SLC30A9 (solute carrier family 30 member 9; also known as ZnT-9) is ubiquitously expressed with high levels in cerebellum, skeletal muscle, thymus and kidney. Confocal analysis of SH-SY5Y cells overexpressing SLC30A9 fused to enhanced green fluorescent protein demonstrated vesicular cytosolic localization associated with the endoplasmic reticulum, not co-localizing with endosomal or Golgi markers. SLC30A9 encodes a putative zinc transporter (by similarity) previously associated with Wnt signalling. However, using dual-luciferase reporter assay in SH-SY5Y cells we showed that Wnt signalling was not affected by the mutation. Based on protein modelling, the identified mutation is expected to affect SLC30A9's highly conserved cation efflux domain, putatively disrupting its transmembrane helix structure. Cytosolic Zn2+ measurements in HEK293 cells overexpressing wild-type and mutant SLC30A9 showed lower zinc concentration within mutant rather than wild-type SLC30A9 cells. This suggests that SLC30A9 has zinc transport properties affecting intracellular zinc homeostasis, and that the molecular mechanism of the disease is through defective function of this novel activity of SLC30A9 rather than by a defect in its previously described role in transcriptional activation of Wnt signalling. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Life-cycle changes and zinc shortage in cadmium-tolerant midges, Chironomus riparius (Diptera), reared in the absence of cadmium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Postma, J.F.; Mol, S.; Larsen, H.

1995-01-01

Adaptation to selected metals is known to modify life-cycle characteristics of some invertebrates and can modify the response to other metals. The reverse process, i.e., adaptation to nonpolluted conditions in a metal-tolerant strain, was studied here for a cadmium-tolerant population of the midge Chironomus riparius to detect whether this backward adaptation followed the same lines. It appeared that cadmium-tolerant populations, reared in the absence of cadmium, continued to suffer from high mortality rates and lowered larval growth rates and reproductive success. Also, some cadmium-tolerant populations accumulated more zinc than did nontolerant populations. Successive experiments in which both cadmium-tolerant and nontolerantmore » populations were exposed to zinc indicated that the reduced growth rate and reproduction were a direct consequence of zinc shortage in tolerant midges reared in the absence of cadmium. Mortality among cadmium-tolerant midges was, however, not lowered by zinc exposure and, judged by their high mortality rates, these midges were even more sensitive to zinc than were nontolerant chironomids. It was concluded that cadmium-tolerant chironomid populations recovering from prolonged exposure are affected by an increased need for zinc as well as by an increased mortality rate as a direct consequence of their earlier adaptation process.« less

Effect of increased concentrations of atmospheric carbon dioxide on the global threat of zinc deficiency: a modelling study.

PubMed

Myers, Samuel S; Wessells, K Ryan; Kloog, Itai; Zanobetti, Antonella; Schwartz, Joel

2015-10-01

Increasing concentrations of atmospheric carbon dioxide (CO2) lower the content of zinc and other nutrients in important food crops. Zinc deficiency is currently responsible for large burdens of disease globally, and the populations who are at highest risk of zinc deficiency also receive most of their dietary zinc from crops. By modelling dietary intake of bioavailable zinc for the populations of 188 countries under both an ambient CO2 and elevated CO2 scenario, we sought to estimate the effect of anthropogenic CO2 emissions on the global risk of zinc deficiency. We estimated per capita per day bioavailable intake of zinc for the populations of 188 countries at ambient CO2 concentrations (375-384 ppm) using food balance sheet data for 2003-07 from the Food and Agriculture Organization. We then used previously published data from free air CO2 enrichment and open-top chamber experiments to model zinc intake at elevated CO2 concentrations (550 ppm, which is the concentration expected by 2050). Estimates developed by the International Zinc Nutrition Consultative Group were used for country-specific theoretical mean daily per-capita physiological requirements for zinc. Finally, we used these data on zinc bioavailability and population-weighted estimated average zinc requirements to estimate the risk of inadequate zinc intake among the populations of the different nations under the two scenarios (ambient and elevated CO2). The difference between the population at risk at elevated and ambient CO2 concentrations (ie, population at new risk of zinc deficiency) was our measure of impact. The total number of people estimated to be placed at new risk of zinc deficiency by 2050 was 138 million (95% CI 120-156). The people likely to be most affected live in Africa and South Asia, with nearly 48 million (32-63) residing in India alone. Global maps of increased risk show significant heterogeneity. Our results indicate that one heretofore unquantified human health effect associated with anthropogenic CO2 emissions will be a significant increase in the human population at risk of zinc deficiency. Our country-specific findings can be used to help guide interventions aimed at reducing this vulnerability. Bill & Melinda Gates Foundation, Winslow Foundation. Copyright © 2015 Myers et al. Open access article published under the terms of CC BY-NC-ND. Published by Elsevier Ltd.. All rights reserved.

Transcriptome sequencing and analysis of zinc-uptake-related genes in Trichophyton mentagrophytes.

PubMed

Zhang, Xinke; Dai, Pengxiu; Gao, Yongping; Gong, Xiaowen; Cui, Hao; Jin, Yipeng; Zhang, Yihua

2017-11-21

Trichophyton mentagrophytes is an important zoonotic dermatophytic (ringworm) pathogen; causing severe skin infection in humans and other animals worldwide. Fortunately, commonly used fungal skin disease prevention and treatment measures are relatively simple. However, T. mentagrophytes is primarily studied at the epidemiology and drug efficacy research levels, yet current study has been unable to meet the needs of clinical medicine. Zinc is a crucial trace element for the growth and reproduction of fungi and other microorganisms. The metal ions coordinate within a variety of proteins to form zinc finger proteins, which perform many vital biological functions. Zinc transport regulatory networks have not been resolved in T. mentagrophytes. The T. mentagrophytes transcriptome will allow us to discover new genes, particularly those genes involved in zinc uptake. We found T. mentagrophytes growth to be restricted by zinc deficiency; natural T. mentagrophytes growth requires zinc ions. T. Mentagrophytes must acquire zinc ions for growth and development. The transcriptome of T. mentagrophytes was sequenced by using Illumina HiSeq™ 2000 technology and the de novo assembly of the transcriptome was performed by using the Trinity method, and functional annotation was analyzed. We got 10,751 unigenes. The growth of T. mentagrophytes is severely inhibited and there were many genes showing significant up regulation and down regulation respectively in T. mentagrophytes when zinc deficiency. Zinc deficiency can affect the expression of multiple genes of T. mentagrophytes. The effect of the zinc deficiency could be recovered in the normal medium. And we finally found the zinc-responsive activating factor (ZafA) and speculated that 4 unigenes are zinc transporters. We knocked ZafA gene by ATMT transformation in T. mentagrophytes, the result showed that ZafA gene is very important for the growth and the generation of conidia in T. mentagrophytes. The expression of 4 zinc transporter genes is potentially regulated by the zinc-responsive activating factor. The data of this study is also sufficient to be used as a support to study T. mentagrophytes. We reported the first large transcriptome study carried out in T. mentagrophytes where we have compared physiological and transcriptional responses to zinc deficiency, and analyzed the expression of genes involved in zinc uptake. The study also produced high-resolution digital profiles of global genes expression relating to T. mentagrophytes growth.

Preparation of organic and water hydrogen for stable isotope analysis. Effects due to reaction vessels and zinc reagent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schimmelmann, A.; DeNiro, M.J.

1993-03-15

Combustion of organic matter in sealed Pyrex, Vycor, and quartz ampules at temperatures between 520 and 900[degrees]C yields less than stoichiometric amounts of water. The loss of hydrogen to hydration reactions between water vapor and glass/quartz interferes with the determination of C/H and N/H elemental ratios in organic matter. The effect increases from quartz to Vycor to Pyrex, but the incomplete yield does not significantly affect the precision and accuracy of the determination of stable hydrogen isotope ratios. Reactions between water and Pyrex do not affect the conversion of water to hydrogen with zinc in Pyrex ampules at 500[degrees]C, whichmore » is quantitative, but even preoutgassed zinc contains a deuterium-depleted hydrogen blank. D/H ratios in hydrogen from the Zn method require a nonlinear correction to achieve compatibility with [delta]D values from the uranium method. 19 refs., 4 tabs.« less

Zinc and selenium accumulation and their effect on iron bioavailability in common bean seeds.

PubMed

de Figueiredo, Marislaine A; Boldrin, Paulo F; Hart, Jonathan J; de Andrade, Messias J B; Guilherme, Luiz R G; Glahn, Raymond P; Li, Li

2017-02-01

Common beans (Phaseolus vulgaris) are the most important legume crops. They represent a major source of micronutrients and a target for essential trace mineral enhancement (i.e. biofortification). To investigate mineral accumulation during seed maturation and to examine whether it is possible to biofortify seeds with multi-micronutrients without affecting mineral bioavailability, three common bean cultivars were treated independently with zinc (Zn) and selenium (Se), the two critical micronutrients that can be effectively enhanced via fertilization. The seed mineral concentrations during seed maturation and the seed Fe bioavailability were analyzed. Common bean seeds were found to respond positively to Zn and Se treatments in accumulating these micronutrients. While the seed pods showed a decrease in Zn and Se along with Fe content during pod development, the seeds maintained relatively constant mineral concentrations during seed maturation. Selenium treatment had minimal effect on the seed accumulation of phytic acid and polyphenols, the compounds affecting Fe bioavailability. Zinc treatment reduced phytic acid level, but did not dramatically affect the concentrations of total polyphenols. Iron bioavailability was found not to be greatly affected in seeds biofortified with Se and Zn. In contrast, the inhibitory polyphenol compounds in the black bean profoundly reduced Fe bioavailability. These results provide valuable information for Se and Zn enhancement in common bean seeds and suggest the possibility to biofortify with these essential nutrients without greatly affecting mineral bioavailability to increase the food quality of common bean seeds. Published by Elsevier Masson SAS.

An MSC2 Promoter-lacZ Fusion Gene Reveals Zinc-Responsive Changes in Sites of Transcription Initiation That Occur across the Yeast Genome

PubMed Central

Wu, Yi-Hsuan; Taggart, Janet; Song, Pamela Xiyao; MacDiarmid, Colin; Eide, David J.

2016-01-01

The Msc2 and Zrg17 proteins of Saccharomyces cerevisiae form a complex to transport zinc into the endoplasmic reticulum. ZRG17 is transcriptionally induced in zinc-limited cells by the Zap1 transcription factor. In this report, we show that MSC2 mRNA also increases (~1.5 fold) in zinc-limited cells. The MSC2 gene has two in-frame ATG codons at its 5’ end, ATG1 and ATG2; ATG2 is the predicted initiation codon. When the MSC2 promoter was fused at ATG2 to the lacZ gene, we found that unlike the chromosomal gene this reporter showed a 4-fold decrease in lacZ mRNA in zinc-limited cells. Surprisingly, β-galactosidase activity generated by this fusion gene increased ~7 fold during zinc deficiency suggesting the influence of post-transcriptional factors. Transcription of MSC2ATG2-lacZ was found to start upstream of ATG1 in zinc-replete cells. In zinc-limited cells, transcription initiation shifted to sites just upstream of ATG2. From the results of mutational and polysome profile analyses, we propose the following explanation for these effects. In zinc-replete cells, MSC2ATG2-lacZ mRNA with long 5’ UTRs fold into secondary structures that inhibit translation. In zinc-limited cells, transcripts with shorter unstructured 5’ UTRs are generated that are more efficiently translated. Surprisingly, chromosomal MSC2 did not show start site shifts in response to zinc status and only shorter 5’ UTRs were observed. However, the shifts that occur in the MSC2ATG2-lacZ construct led us to identify significant transcription start site changes affecting the expression of ~3% of all genes. Therefore, zinc status can profoundly alter transcription initiation across the yeast genome. PMID:27657924

Feeding Low or Pharmacological Concentrations of Zinc Oxide Changes the Hepatic Proteome Profiles in Weaned Piglets

PubMed Central

Bondzio, Angelika; Pieper, Robert; Gabler, Christoph; Weise, Christoph; Schulze, Petra; Zentek, Juergen; Einspanier, Ralf

2013-01-01

Pharmacological levels of zinc oxide can promote growth and health of weaning piglets, but the underlying molecular mechanisms are yet not fully understood. The aim of this study was to determine changes in the global hepatic protein expression in response to dietary zinc oxide in weaned piglets. Nine half-sib piglets were allocated to three dietary zinc treatment groups (50, 150, 2500 mg/kg dry matter). After 14 d, pigs were euthanized and liver samples taken. The increase in hepatic zinc concentration following dietary supplementation of zinc was accompanied by up-regulation of metallothionein mRNA and protein expression. Global hepatic protein profiles were obtained by two-dimensional difference gel electrophoresis following matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. A total of 15 proteins were differentially (P<0.05) expressed between groups receiving control (150 mg/kg) or pharmacological levels of zinc (2500 mg/kg) with 7 down- (e.g. arginase1, thiosulfate sulfurtransferase, HSP70) and 8 up-regulated (e.g. apolipoprotein AI, transferrin, C1-tetrahydrofolate synthase) proteins. Additionally, three proteins were differentially expressed with low zinc supply (50 mg/kg Zn) in comparison to the control diet. The identified proteins were mainly associated with functions related to cellular stress, transport, metabolism, and signal transduction. The differential regulation was evaluated at the mRNA level and a subset of three proteins of different functional groups was selected for confirmation by western blotting. The results of this proteomic study suggest that zinc affects important liver functions such as blood protein secretion, protein metabolism, detoxification and redox homeostasis, thus supporting the hypothesis of intermediary effects of pharmacological levels of zinc oxide fed to pigs. PMID:24282572

Molecular basis for subtype-specificity and high-affinity zinc inhibition in the GluN1-GluN2A NMDA receptor amino terminal domain

PubMed Central

Romero-Hernandez, Annabel; Simorowski, Noriko; Karakas, Erkan

2016-01-01

Summary Zinc is vastly present in the mammalian brain and controls functions of various cell surface receptors to regulate neurotransmission. A distinctive characteristic of N-methyl-D-aspartate (NMDA) receptors containing a GluN2A subunit is that their ion channel activity is allosterically inhibited by a nano-molar concentration of zinc that binds to an extracellular domain called an amino terminal domain (ATD). Despite physiological importance, the molecular mechanism underlying the high-affinity zinc inhibition has been incomplete due to lack of a GluN2A ATD structure. Here we show the first crystal structures of the heterodimeric GluN1-GluN2A ATD, which provide the complete map of the high-affinity zinc binding site and reveals distinctive features from the ATD of the GluN1-GluN2B subtype. Perturbation of hydrogen bond networks at the hinge of the GluN2A bi-lobe structure affects both zinc inhibition and open probability supporting the general model where the bi-lobe motion in ATD regulates the channel activity in NMDA receptors. PMID:27916457

Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

PubMed

Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

2017-03-01

Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P < 0.03); both did not differ from 57 FePP-Zn: 4.0% (2.8%, 5.6%). Relative iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P < 0.02) but not from that of 57 FePP+ZnO (10.2% compared with 13.1%; P = 0.08). Conclusions: In iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with ZnO. These findings suggest that ZnSO 4 may be the preferable zinc cofortificant for optimal iron bioavailability of iron-fortified extruded rice. This trial was registered at clinicaltrials.gov as NCT02255942. © 2017 American Society for Nutrition.

Zinc allocation and re-allocation in rice.

PubMed

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E L; Struik, Paul C

2014-01-01

Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Two solution culture experiments using (70)Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg(-1) dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement.

Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity☆

PubMed Central

Milacic, Vesna; Chen, Di; Giovagnini, Lorena; Diez, Alejandro; Fregona, Dolores; Dou, Q. Ping

2013-01-01

Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC50 value of 13.8 μM, which was less potent than copper(II) chloride (IC50 5.3 μM). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells. PMID:18501397

Zinc allocation and re-allocation in rice

PubMed Central

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E. L.; Struik, Paul C.

2014-01-01

Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg−1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement. PMID:24478788

Effect of Zinc-Deficient Diet on Oral Tissues and Periodontal Indices in Rats

PubMed Central

Seyedmajidi, Seyed Ali; Seyedmajidi, Maryam; Moghadamnia, Aliakbar; Khani, Zohreh; Zahedpasha, Samir; Jenabian, Niloofar; Jorsaraei, Gholamali; Halalkhor, Sohrab; Motallebnejad, Mina

2014-01-01

Zinc (Zn) as a nutritional factor affects the health of the oral tissues. This study was done for the evaluation of the effects of zinc deficiency on the oral tissues of rats. The study was carried out on 14 male Wistar rats, cessation of lactation on the 24th day after birth. The rats were randomly divided into two groups. Zinc deficient (ZD) diet was used for one group and another group was fed with a zinc-containing (ZC) diet. The alterations of the oral tissues in both groups were evaluated clinically after four weeks. Also the gingival index and periodontal pocket depth were recorded. The measurement of serum zinc level was done by atomic absorption spectrophotometry. The microscopic slides of oral tissue specimen were evaluated quantitatively. The serum zinc level of the ZD rats was lower than the ZC group (p< 0.001). According clinical findings, the gingival index was lower in ZC rat (p=0.001), but there was no significant difference regarding the periodontal pocket depth between two groups (p=0.07). Aphthous ulcer was observed in ZD rats on the floor of the mouth. There was no significant difference regarding the epithelial and keratin thickening between two groups. This study indicated that oral and periodontal health was better in ZC rats than in ZD rats. Aphthous lesions were more prominent in ZD rats. This study confirmed that zinc deficiency may endanger oral and periodo ntal structures. PMID:25035857

On The Effect Of Zinc Melt Composition On The Structure Of Hot-Dip Galvanized Coatings

NASA Astrophysics Data System (ADS)

Konidaris, S.; Pistofidis, N.; Vourlias, G.; Pavlidou, E.; Stergiou, A.; Stergioudis, G.; Polychroniadis, E. K.

2007-04-01

Zinc hot-dip galvanizing is an effective method for the corrosion protection of ferrous materials. A way of improving the results is through the addition of various elements in the zinc melt. In the present work the effect of Ni, Bi, Cr, Mn, Se and Si at concentration of 0.5 or 1.5 wt.% was examined. Coupons of carbon steel St-37 were coated with zinc containing the above-mentioned elements and were exposed in a Salt Spray Chamber (SSC). The micro structure of these coatings was examined with SEM and XRD. In every case the usual morphology was observed, while differences at the thickness and the crystal size of each layer were induced. However the alloying elements were present in the coating affecting its reactivity and, at least in the case of Mn and Cr, improving corrosion resistance.

Double layer effects on metal nucleation in deep eutectic solvents.

PubMed

Abbott, Andrew P; Barron, John C; Frisch, Gero; Gurman, Stephen; Ryder, Karl S; Fernando Silva, A

2011-06-07

The electrodeposition of zinc has been studied in two deep eutectic solvents. Unlike the metals studied to date in these liquids, zinc electrodeposition is not mass transport limited and the morphology of the deposit differs in the two liquids. This study shows that changing the concentration of solute affects the physical properties of the liquid to different extents although this is found to not effect the morphology of the metal deposited. EXAFS was used to show that the speciation of zinc was the same in both liquids. Double layer capacitance studies showed differences between the two liquids and these are proposed to be due to the adsorption of a species on the electrode which is thought to be chloride. The differences in zinc morphology is attributed to blocking of certain crystal faces leading to deposition of small platelet shaped crystals in the glycol based liquid.

Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Juanjuan; Zhang, Yu; Xu, Wentao, E-mail: xuwentaoboy@sina.com

Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did notmore » affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{sub m}). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by OTA in vitro.« less

Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis.

PubMed

Mahmoud, Abeer M; Al-Alem, Umaima; Dabbous, Firas; Ali, Mohamed M; Batai, Ken; Shah, Ebony; Kittles, Rick A

2016-01-01

Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR <6.5 vs 6.5-12.5mg/day 1.8, 95% CI: 0.6,5.6; OR <6.5 vs >12.5mg/day 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07hi vs lo 95% CI: 0.98-1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc intake and prostate cancer.

Measurement of total Zn and Zn isotope ratios by quadrupole ICP-MS for evaluation of Zn uptake in gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Wolf, R.E.; Todd, A.S.; Brinkman, S.; Lamothe, P.J.; Smith, K.S.; Ranville, J.F.

2009-01-01

This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the 67Zn/66Zn ratios for planned exposure levels and duration. After completion of the pilot study, a full-scale zinc exposure study using rainbow trout was performed. The results of these studies indicate that there are several factors that affect the precision of the measured 67Zn/66Zn ratios in the sample digests, including variations in sample size, endogenous zinc levels, and zinc uptake rates by individual fish. However, since these factors were incorporated in the calculation of the total zinc accumulated by the gills during the exposures, the data obtained were adequate for their intended use in calculating zinc binding and evaluating the influences of differences in water quality parameters.

Antepartum/postpartum depressive symptoms and serum zinc and magnesium levels.

PubMed

Wójcik, Jacek; Dudek, Dominika; Schlegel-Zawadzka, Małgorzata; Grabowska, Mariola; Marcinek, Antoni; Florek, Ewa; Piekoszewski, Wojciech; Nowak, Rafał J; Opoka, Włodzimierz; Nowak, Gabriel

2006-01-01

In the present study, we investigated the relationship between depressive symptoms and serum zinc and magnesium level in antepartum and postpartum women. All women received standard vitamin, zinc and magnesium supplementation. Sixty-six pregnant women in the Czerwiakowski Hospital in Kraków were assessed for prepartum depressive symptoms using the Beck Depression Inventory (BDI). Sixty-two and fifty-eight women were also assessed for postpartum depressive symptoms (using Edinburgh Postnatal Depression Rating Scale, EPDRS) at 3 and 30 days after delivery, respectively. Serum zinc and magnesium levels were also determined at these time points, however, the number of examined subjects were diminished. A significantly higher EPDRS score (by 45%), indicating severity of depressive symptoms, was found on the 3rd day after childbirth compared with the 30th postpartum day. Moreover, the early post-delivery period (3rd day) was characterized by a 24% lower serum zinc concentration than that found on the 30th day after childbirth. BDI scores assessed a month before childbirth revealed mild depressive symptoms, which was accompanied by a serum zinc concentration similar to that found on the 3rd day after delivery. No significant alterations were found in the magnesium levels between these time points. The present results demonstrated a relationship between severity of depressive symptoms and decreased serum zinc (but not magnesium) concentration in a very specific type of affective disorder, the postpartum depression.

Study of mixed Ca-Zn hydroxyapatite surface modified by lactic acid

NASA Astrophysics Data System (ADS)

Turki, Thouraya; Aissa, Abdallah; Bac, Christophe Goze; Rachdi, Férid; Debbabi, Mongi

2012-07-01

The new hybrid inorganic-organic composites, Ca(10-x)Znx(PO4)6(OH)2-lactic acid, at different amounts of zinc and lactic acid were prepared by dissolution of the organic compound in an hydroxyapatite suspension. They were characterized by XRD, IR, MAS NMR (13C and 1H) and chemical analysis. The crystallinity was slightly affected by the presence of organic fragments. IR and (13C and 1H) MAS NMR measurements indicate that the carboxylic groups of the acid interact with calcium and zinc ions of hydroxyapatite surface. Chemical analysis displays that zinc promotes the acid grafting. A mechanism of surface modification is proposed based on the obtained results.

Mercury Poisoning from an Unsuspected Source

PubMed Central

Tamir, M.; Bornstein, B.; Behar, M.; Chwat, M.

1964-01-01

In the manufacture of zinc oxide the raw material normally used in zinc metal plates. In a factory in which old aeroplane batteries containing zinc mercury amalgam were substituted, it was not realized that mercury vapour was being produced. Of 25 workers exposed, seven developed serious chronic mercury poisoning and were admitted to hospital. The clinical findings in the affected workers are described. They were first treated with penicillamine D, but in all but one case this had to be stopped because of rashes. Little improvement followed a switch to B.A.L. It is suggested that if penicillamine D is used in the treatment of mercury poisoning, steroid cover should be given from the start. PMID:14249900

Effect of Zinc Supplementation on Pregnancy and Infant Outcomes: A Systematic Review

PubMed Central

Chaffee, Benjamin W.; King, Janet C.

2013-01-01

Poor maternal zinc status has been associated with foetal loss, congenital malformations, intrauterine growth retardation, reduced birth weight, prolonged labour and preterm or post-term deliveries. A meta-analysis completed in 2007 showed that maternal zinc supplementation resulted in a small but significant reduction in preterm birth. The purposes of this analysis are to update that previous review and expand the scope of assessment to include maternal, infant and child health outcomes. Electronic searches were carried out to identify peer-reviewed, randomised controlled trials where daily zinc supplementation was given for at least one trimester of pregnancy. The co-authors applied the study selection criteria, assessed trial quality and abstracted data. A total of 20 independent intervention trials involving more than 11 000 births were identified. The 20 trials took place across five continents between 1977 and 2008. Most studies assessed the zinc effect against a background of other micronutrient supplements, but five were placebo-controlled trials of zinc alone. The provided dose of supplemental zinc ranged from 5 to 50 mg/day. Only the risk of preterm birth reached statistical significance (summary relative risk 0.86 [95% confidence interval 0.75, 0.99]). There was no evidence that supplemental zinc affected any parameter of foetal growth (risk of low birth weight, birth weight, length at birth or head circumference at birth). Six of the 20 trials were graded as high quality. The evidence that maternal zinc supplementation lowers the risk of preterm birth was graded low; evidence for a positive effect on other foetal outcomes was graded as very low. The effect of zinc supplementation on preterm birth, if causal, might reflect a reduction in maternal infection, a primary cause of prematurity. While further study would be needed to explore this possibility in detail, the overall public health benefit of zinc supplementation in pregnancy appears limited. PMID:22742606

Comparison of proteome response to saline and zinc stress in lettuce

PubMed Central

Lucini, Luigi; Bernardo, Letizia

2015-01-01

Zinc salts occurring in soils can exert an osmotic stress toward plants. However, being zinc a heavy metal, some more specific effects on plant metabolisms can be forecast. In this work, lettuce has been used as a model to investigate salt and zinc stresses at proteome level through a shotgun tandem MS proteomic approach. The effect of zinc stress in lettuce, in comparison with NaCl stress, was evaluated to dissect between osmotic/oxidative stress related effects, from those changes specifically related to zinc. The analysis of proteins exhibiting a fold change of 3 as minimum (on log 2 normalized abundances), revealed the involvement of photosynthesis (via stimulation of chlorophyll synthesis and enhanced role of photosystem I) as well as stimulation of photophosphorylation. Increased glycolytic supply of energy substrates and ammonium assimilation [through formation of glutamine synthetase (GS)] were also induced by zinc in soil. Similarly, protein metabolism (at both transcriptional and ribosomal level), heat shock proteins, and proteolysis were affected. According to their biosynthetic enzymes, hormones appear to be altered by both the treatment and the time point considered: ethylene biosynthesis was enhanced, while production of abscisic acid was up-regulated at the earlier time point to decrease markedly and gibberellins were decreased at the later one. Besides aquaporin PIP2 synthesis, other osmotic/oxidative stress related compounds were enhanced under zinc stress, i.e., proline, hydroxycinnamic acids, ascorbate, sesquiterpene lactones, and terpenoids biosynthesis. Although the proteins involved in the response to zinc stress and to salinity were substantially the same, their abundance changed between the two treatments. Lettuce response to zinc was more prominent at the first sampling point, yet showing a faster adaptation than under NaCl stress. Indeed, lettuce plants showed an adaptation after 30 days of stress, in a more pronounced way in the case of zinc. PMID:25932029

Loss of ErbB2-PI3K/Akt signaling prevents zinc pyrithione-induced cardioprotection during ischemia/reperfusion.

PubMed

Thokala, Sandhya; Inapurapu, Santhipriya; Bodiga, Vijaya Lakshmi; Vemuri, Praveen Kumar; Bodiga, Sreedhar

2017-04-01

The purpose of this study was to determine if zinc homeostasis is affected during ischemia/reperfusion, if so, whether zinc pyrithione limits myocardial cell death and improves hemodynamics when administered as an adjunct to reperfusion and if ErbB receptor tyrosine kinases that are important for the long-term structural integrity of the heart are indispensable for reperfusion salvage. Isolated perfused rat hearts were subjected to 35min of global ischemia and reperfused for 120min to determine the relative intracellular zinc levels by TSQ staining. The hearts were reperfused in the presence of incremental concentrations of zinc pyrithione for the first 10min during reperfusion. Silencing or blockade of ErbB2 using a monoclonal antibody, ErbB2 kinase inhibition and PI3kinase inhibition was used to study their critical role in zinc pyrithione-induced cardioprotection. We found that there was a profound decrease in intracellular zinc after ischemia/reperfusion resulting in increased apoptosis, caspase-3 activation, and infarct size. A dose-dependent reduction of infarct size with zinc pyrithione in the range of 5-20μmol/l (optimal protection was seen at 10μmol/l with infarct size of 16±2% vs. I/R vehicle, 33±2%, p<0.01). Increased TUNEL staining and caspase-3 activity observed after ischemia/reperfusion were attenuated by zinc pyrithione administration during the reperfusion. Moreover, this protection was sensitive to silencing and blockade of ErbB2, inhibition of ErbB2 kinase activity or PI3-kinase activity. Western blot analysis revealed that zinc pyrithione resulted in decreased caspase-3 activation, rapid stabilization of ErbB2/ErbB1 heterodimers, and increased activation of PI3K/Akt signaling cascade. Zinc pyrithione attenuates lethal perfusion-induced injury in a manner that is reliant on ErbB2/PI3K/Akt activity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Zinc deficiency exacerbates while zinc supplement attenuates cardiac hypertrophy in high-fat diet-induced obese mice through modulating p38 MAPK-dependent signaling.

PubMed

Wang, Shudong; Luo, Manyu; Zhang, Zhiguo; Gu, Junlian; Chen, Jing; Payne, Kristen McClung; Tan, Yi; Wang, Yuehui; Yin, Xia; Zhang, Xiang; Liu, Gilbert C; Wintergerst, Kupper; Liu, Quan; Zheng, Yang; Cai, Lu

2016-09-06

Childhood obesity often leads to cardiovascular diseases, such as obesity-related cardiac hypertrophy (ORCH), in adulthood, due to chronic cardiac inflammation. Zinc is structurally and functionally essential for many transcription factors; however, its role in ORCH and underlying mechanism(s) remain unclear and were explored here in mice with obesity induced with high-fat diet (HFD). Four week old mice were fed on either HFD (60%kcal fat) or normal diet (ND, 10% kcal fat) for 3 or 6 months, respectively. Either diet contained one of three different zinc quantities: deficiency (ZD, 10mg zinc per 4057kcal), normal (ZN, 30mg zinc per 4057kcal) or supplement (ZS, 90mg zinc per 4057kcal). HFD induced a time-dependent obesity and ORCH, which was accompanied by increased cardiac inflammation and p38 MAPK activation. These effects were worsened by ZD in HFD/ZD mice and attenuated by ZS in HFD/ZS group, respectively. Also, administration of a p38 MAPK specific inhibitor in HFD mice for 3 months did not affect HFD-induced obesity, but completely abolished HFD-induced, and zinc deficiency-worsened, ORCH and cardiac inflammation. In vitro exposure of adult cardiomyocytes to palmitate induced cell hypertrophy accompanied by increased p38 MAPK activation, which was heightened by zinc depletion with its chelator TPEN. Inhibition of p38 MAPK with its specific siRNA also prevented the effects of palmitate on cardiomyocytes. These findings demonstrate that ZS alleviates but ZD heightens cardiac hypertrophy in HFD-induced obese mice through suppressing p38 MAPK-dependent cardiac inflammatory and hypertrophic pathways. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Determination of the Optimum Conditions for Leaching of Zinc Cathode Melting Furnace Slag in Ammonium Chloride Media

NASA Astrophysics Data System (ADS)

Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

2014-04-01

This research is part of a continuing effort to leach zinc from zinc cathode melting furnace slags (ZCMFSs) to produce zinc oxide. The slag with an assay of 68.05 pct Zn was used in ammonium chloride leaching for zinc extraction. In this paper, the effects of influential factors on extraction efficiency of Zn from a ZCMFS were investigated. The Taguchi's method based on orthogonal array (OA) design has been used to arrange the experimental runs in order to maximize zinc extraction from a slag. The softwares named Excel and Design-Expert 7 have been used to design experiments and subsequent analysis. OA L 25 (55) consisting of five parameters, each with five levels, was employed to evaluate the effects of reaction time ( t = 10, 30, 50, 70, 90 minutes), reaction temperature [ T = 313, 323, 333, 343, 353 (40, 50, 60, 70, 80) K (°C)], pulp density ( S/ L = 20, 40, 60, 80, 100 g/L), stirring speed ( R = 300, 400, 500, 600, 700 rpm), and ammonium chloride concentration ( C = 10, 15, 20, 25, 30 pctwt), on zinc extraction percent. Statistical analysis, ANOVA, was also employed to determine the relationship between experimental conditions and yield levels. The results showed that the significant parameters affecting leaching of slag were ammonium chloride concentration and pulp density, and increasing pulp density reduced leaching efficiency of zinc. However, increasing ammonium chloride concentration promoted the extraction of zinc. The optimum conditions for this study were found to be t 4: 70 minutes, T 5: 353 K (80 °C), ( S/ L)2: 40 g/L, R 3: 500 rpm, and C 4: 25 pctwt. Under these conditions, the dissolution percentage of Zn in ammonium chloride media was 94.61 pct.

Risk of zinc, iodine and other micronutrient deficiencies among school children in North East Thailand.

PubMed

Thurlow, R A; Winichagoon, P; Pongcharoen, T; Gowachirapant, S; Boonpraderm, A; Manger, M S; Bailey, K B; Wasantwisut, E; Gibson, R S

2006-05-01

Micronutrient deficiencies during childhood can contribute to impairments in growth, immune competence, and mental and physical development, and the coexistence of several such deficiencies can adversely affect the efficacy of single micronutrient interventions. To assess the prevalence of zinc and iodine deficiency and their interrelationships with vitamin A deficiency and anemia and associations with socio-economic status, hemoglobin type, and anthropometry in a cross-sectional study. A total of 10 primary schools in North East Thailand. Non-fasting venipuncture blood samples and casual urine samples were collected from 567 children aged 6-13 years. Anthropometric measures and serum zinc, albumin, C-reactive protein and urinary iodine, are reported here and integrated with published data on vitamin A, anemia, and socio-economic status. Of the children, 57% had low serum zinc and 83% had urinary iodine levels below the 100 microg/l cutoff. Suboptimal serum zinc and urinary iodine concentrations may result from low intakes of zinc and iodized salt. Significant risk factors for low serum zinc were serum retinol <1.05 micromol/l and being male. Those for urinary iodine <100 microg/l were height-for-age score>median and being female. For serum retinol <1.05 micromol/l, risk factors were low hemoglobin, low serum zinc, and <9 years, and for low hemoglobin indicative of anemia risk factors were <9 years, AE hemoglobinopathy, and serum retinol <1.05 micromol/l. Of the children, 60% were at risk of two or more coexisting micronutrient deficiencies, most commonly suboptimal urinary iodine and low serum zinc. The findings emphasize the need for multimicronutrient interventions in North East Thailand.

Endocrine disruptor & nutritional effects of heavy metals in ovarian hyperstimulation.

PubMed

Dickerson, E H; Sathyapalan, T; Knight, R; Maguiness, S M; Killick, S R; Robinson, J; Atkin, S L

2011-12-01

There is increasing concern that environmental chemicals have a direct effect on fertility. Heavy metals such as mercury have been shown to affect various organ systems in humans including nervous system and skin, however they could also act as endocrine disrupting chemicals adversely affecting fertility. Metals such as zinc and selenium are essential micronutrients with diverse functions that may be important for reproductive outcomes. We measured mercury, zinc and selenium levels in the hair, a reliable reflection of long term environmental exposure and dietary status, to correlate with the outcome of ovarian hyperstimulation for in vitro fertilisation (IVF) treatment. We analysed the hair of 30 subfertile women for mercury, zinc and selenium using inductively coupled mass spectrometry. Each woman underwent one cycle of IVF treatment. Correlation between the levels of these trace metals and treatment outcomes was investigated. Thirty women were recruited with mean (±SD) age of 32.7(4.4) years and BMI of 25.4(5.0)kg/m(2). Hair mercury concentration showed a negative correlation with oocyte yield (p < 0.05,βcoefficient 0.38) and follicle number (p = 0.03,β coefficient0.19) after ovarian stimulation. Zinc and selenium levels in hair correlated positively with oocyte yield after ovarian stimulation (p < 0.05,β coefficient0.15) and (p = 0.03,β coefficient0.21) respectively. Selenium levels in hair correlated significantly with follicle number following stimulation (p = 0.04, βcoefficient0.22). There was no correlation between mercury, zinc and selenium in hair and their corresponding serum levels. These data suggest that mercury had a deleterious effect whilst there was a positive effect for zinc and selenium in the ovarian response to gonadotrophin therapy for IVF. Hair analysis offers a novel method of investigating the impact of long-term exposure to endocrine disruptors and nutritional status on reproductive outcomes.

Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

PubMed

Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

2011-12-06

The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

Fidelity of metal insertion into hydrogenases.

PubMed

Magalon, A; Blokesch, M; Zehelein, E; Böck, A

2001-06-15

The fidelity of metal incorporation into the active center of hydrogenase 3 from Escherichia coli was studied by analyzing the inhibition of the maturation pathway by zinc and other transition metals. Hydrogenase maturation of wild-type cells was significantly affected only by concentrations of zinc or cadmium higher than 200 microM, whereas a mutant with a lesion in the nickel uptake system displayed a total blockade of the proteolytic processing of the precursor form into the mature form of the large subunit after growth in the presence of 10 microM Zn(2+). The precursor could not be processed in vitro by the maturation endopeptidase even in the presence of an excess of nickel ions. Evidence is presented that zinc does not interfere with the incorporation of iron into the metal center. Precursor of the large subunit accumulated in nickel proficient cells formed a transient substrate complex with the cognate endoprotease HycI whereas that of zinc-supplemented cells did not. The results show that zinc can intrude the nickel-dependent maturation pathway only when nickel uptake is blocked. Under this condition zinc appears to be incorporated at the nickel site of the large subunit and delivers a precursor not amenable to proteolytic processing since the interaction with the endoprotease is blocked.

Effects of Zinc Supplementation on Endocrine Outcomes in Women with Polycystic Ovary Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial.

PubMed

Jamilian, Mehri; Foroozanfard, Fatemeh; Bahmani, Fereshteh; Talaee, Rezvan; Monavari, Mahshid; Asemi, Zatollah

2016-04-01

The current study was conducted to evaluate the effects of zinc supplementation on endocrine outcomes, biomarkers of inflammation, and oxidative stress in patients with polycystic ovary syndrome (PCOS). This study was a randomized double-blind, placebo-controlled trial. Forty-eight women (18-40 years) with PCOS diagnosed according to Rotterdam criteria were randomly assigned to receive either 220 mg zinc sulfate (containing 50 mg zinc) (group 1; n = 24) and/or placebo (group 2; n = 24) for 8 weeks. Hormonal profiles, biomarkers of inflammation, and oxidative stress were measured at study baseline and after 8-week intervention. After 8 weeks of intervention, alopecia (41.7 vs. 12.5%, P = 0.02) decreased compared with the placebo. Additionally, patients who received zinc supplements had significantly decreased hirsutism (modified Ferriman-Gallwey scores) (-1.71 ± 0.99 vs. -0.29 ± 0.95, P < 0.001) and plasma malondialdehyde (MDA) levels (-0.09 ± 1.31 vs. +2.34 ± 5.53 μmol/L, P = 0.04) compared with the placebo. A trend toward a significant effect of zinc intake on reducing high-sensitivity C-reactive protein (hs-CRP) levels (P = 0.06) was also observed. We did observe no significant changes of zinc supplementation on hormonal profiles, inflammatory cytokines, and other biomarkers of oxidative stress. In conclusion, using 50 mg/day elemental zinc for 8 weeks among PCOS women had beneficial effects on alopecia, hirsutism, and plasma MDA levels; however, it did not affect hormonal profiles, inflammatory cytokines, and other biomarkers of oxidative stress.

Development of stress tolerant Saccharomyces cerevisiae strains by metabolic engineering: New aspects from cell flocculation and zinc supplementation.

PubMed

Cheng, Cheng; Zhang, Mingming; Xue, Chuang; Bai, Fengwu; Zhao, Xinqing

2017-02-01

Budding yeast Saccharomyces cerevisiae is widely studied for the production of biofuels from lignocellulosic biomass. However, economic production is currently challenged by the repression of cell growth and compromised fermentation performance of S. cerevisiae strains in the presence of various environmental stresses, including toxic level of final products, inhibitory compounds released from the pretreatment of cellulosic feedstocks, high temperature, and so on. Therefore, it is important to improve stress tolerance of S. cerevisiae to these stressful conditions to achieve efficient and economic production. In this review, the latest advances on development of stress tolerant S. cerevisiae strains are summarized, with the emphasis on the impact of cell flocculation and zinc addition. It was found that cell flocculation affected ethanol tolerance and acetic acid tolerance of S. cerevisiae, and addition of zinc to a suitable level improved stress tolerance of yeast cells to ethanol, high temperature and acetic acid. Further studies on the underlying mechanisms by which cell flocculation and zinc status affect stress tolerance will not only enrich our knowledge on stress response and tolerance mechanisms of S. cerevisiae, but also provide novel metabolic engineering strategies to develop robust yeast strains for biofuels production. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Effect of dietary phytate on zinc homeostasis in young and elderly Korean women.

PubMed

Kim, Jihye; Paik, Hee Young; Joung, Hyojee; Woodhouse, Leslie R; Li, Shanji; King, Janet C

2007-02-01

Previous studies suggest that consumption of predominantly plant-based diets with high phytate content contribute to zinc deficiency by inhibiting zinc absorption. Age of the individual may also affect the ability to maintain zinc homeostasis. This study was designed to determine the effect of dietary phytate on zinc homeostasis and to evaluate the effect of age on the capacity to maintain the zinc homeostasis with changes in dietary phytate in young and elderly Korean women. Seven healthy young women (22-24 yr) and 10 healthy elderly women (66-75 yr) were studied consecutively for 3 months in 2 metabolic periods (MP) in two different metabolic units. During MP1 the women consumed a high phytate (HP) diet (P:Zn molar ratio = 23) for 9 days. After a 10 d wash-out period at home eating their usual diets, a lower phytate diet (LP) (P:Zn molar ratio = 10) was fed in MP2 for 9 d. Phytase was added to selected foods in the high phytate diet to reduce the phytate content of the meals in the LP period. The zinc content of both diets was about 6.5 mg/d. Stable isotopes of Zn ((70)Zn) were administered intravenously on d 5 of MP 1 and 2 for measuring endogenous fecal zinc excretion. Plasma samples were also collected on d 5 for measuring plasma zinc concentrations by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). 24 hr urine samples were collected for 5 d and complete fecal samples were collected for 9 d after isotope administration. Fractional zinc absorption (FZA) was calculated from mass balance corrected for endogenous fecal zinc (EFZ) excretion and EFZ was determined by using an isotopic dilution technique. Isotopic ratios for FZA and EFZ were measured by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Statistical analyses were done using ANOVA. Both the young and elderly women were in negative zinc balance during the HP period. This was due to a significant decrease in FZA and total absorbed zinc (TAZ) with a HP diet (43 vs 22% in young women, 34 vs 20% in elderly women, p < 0.001). EFZ excretion did not differ in the young and elderly women during the LP and HP periods. Dietary phytate did not alter plasma zinc concentrations or and urinary zinc excretion in either group. Adjustments in zinc homeostasis with an increase in dietary phytate did not differ between young and elderly women in this study.

Zinc or copper deficiency-induced impaired inflammatory response to brain trauma may be caused by the concomitant metallothionein changes.

PubMed

Penkowa, M; Giralt, M; Thomsen, P S; Carrasco, J; Hidalgo, J

2001-04-01

The role of zinc- and copper-deficient diets on the inflammatory response to traumatic brain injury (TBI) has been evaluated in adult rats. As expected, zinc deficiency decreased food intake and body weight gain, and the latter effect was higher than that observed in pair-fed rats. In noninjured brains, zinc deficiency only affected significantly lectin (increasing) and glial fibrillary acidic protein (GFAP) and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (decreasing) immunoreactivities (irs). In injured brains, a profound gliosis was observed in the area surrounding the lesion, along with severe damage to neurons as indicated by neuron specific enolase (NSE) ir, and the number of cells undergoing apoptosis (measured by TUNEL) was dramatically increased. Zinc deficiency significantly altered brain response to TBI, potentiating the microgliosis and reducing the astrogliosis, while increasing the number of apoptotic cells. Metallothioneins (MTs) are important zinc- and copper-binding proteins in the CNS, which could influence significantly the brain response to TBI because of their putative roles in metal homeostasis and antioxidant defenses. MT-I+II expression was dramatically increased by TBI, and this response was significantly blunted by zinc deficiency. The MT-III isoform was moderately increased by both TBI and zinc deficiency. TBI strongly increased oxidative stress levels, as demonstrated by malondialdehyde (MDA), protein tyrosine nitration (NITT), and nuclear factor kappaB (NF-kappaB) levels irs, all of which were potentiated by zinc deficiency. Further analysis revealed unbalanced expression of prooxidant and antioxidant proteins besides MT, since the levels of inducible nitric oxide synthase (iNOS) and Cu,Zn-SOD were increased and decreased, respectively, by zinc deficiency. All these effects were attributable to zinc deficiency, since pair-fed rats did not differ from normally fed rats. In general, copper deficiency caused a similar pattern of responses, albeit more moderate. Results obtained in mice with a null mutation for the MT-I+II isoforms strongly suggest that most of the effects observed in the rat brain after zinc and copper deficiencies are attributable to the concomitant changes in the MT expression.

Zinc rescues obesity-induced cardiac hypertrophy via stimulating metallothionein to suppress oxidative stress-activated BCL10/CARD9/p38 MAPK pathway.

PubMed

Wang, Shudong; Gu, Junlian; Xu, Zheng; Zhang, Zhiguo; Bai, Tao; Xu, Jianxiang; Cai, Jun; Barnes, Gregory; Liu, Qiu-Ju; Freedman, Jonathan H; Wang, Yonggang; Liu, Quan; Zheng, Yang; Cai, Lu

2017-06-01

Obesity often leads to obesity-related cardiac hypertrophy (ORCH), which is suppressed by zinc-induced inactivation of p38 mitogen-activated protein kinase (p38 MAPK). In this study, we investigated the mechanisms by which zinc inactivates p38 MAPK to prevent ORCH. Mice (4-week old) were fed either high fat diet (HFD, 60% kcal fat) or normal diet (ND, 10% kcal fat) containing variable amounts of zinc (deficiency, normal and supplement) for 3 and 6 months. P38 MAPK siRNA and the p38 MAPK inhibitor SB203580 were used to suppress p38 MAPK activity in vitro and in vivo, respectively. HFD activated p38 MAPK and increased expression of B-cell lymphoma/CLL 10 (BCL10) and caspase recruitment domain family member 9 (CARD9). These responses were enhanced by zinc deficiency and attenuated by zinc supplement. Administration of SB203580 to HFD mice or specific siRNA in palmitate-treated cardiomyocytes eliminated the HFD and zinc deficiency activation of p38 MAPK, but did not significantly impact the expression of BCL10 and CARD9. In cultured cardiomyocytes, inhibition of BCL10 expression by siRNA prevented palmitate-induced increased p38 MAPK activation and atrial natriuretic peptide (ANP) expression. In contrast, inhibition of p38 MAPK prevented ANP expression, but did not affect BCL10 expression. Deletion of metallothionein abolished the protective effect of zinc on palmitate-induced up-regulation of BCL10 and phospho-p38 MAPK. HFD and zinc deficiency synergistically induce ORCH by increasing oxidative stress-mediated activation of BCL10/CARD9/p38 MAPK signalling. Zinc supplement ameliorates ORCH through activation of metallothionein to repress oxidative stress-activated BCL10 expression and p38 MAPK activation. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Characterization of zinc stress response in Cyanobacterium Synechococcus sp. IU 625.

PubMed

Newby, Robert; Lee, Lee H; Perez, Jose L; Tao, Xin; Chu, Tinchun

2017-05-01

The ability of cyanobacteria to survive many environmental stress factors is a testament to their resilience in nature. Of these environmental stress factors, overexposure to zinc is important to study since excessive zinc intake can be a severe hazard. Zinc toxicity in freshwater has been demonstrated to affects organisms such as invertebrates, algae and cyanobacteria. Cyanobacteria which possess increased resistance to zinc have been isolated. It is therefore important to elucidate the mechanism of survival and response to determine what factors allow their survival; as well as any remediation implications they may have. To characterize the effects of zinc in freshwater cyanobacteria, we investigated the response of Synechococcus sp. IU 625 (S. IU 625) over 29days to various concentrations (10, 25, and 50mg/L) of ZnCl 2 . S. IU 625 was shown to be tolerant up to 25mg/L ZnCl 2 exposure, with 10mg/L ZnCl 2 having no outward physiological change and 50mg/L ZnCl 2 proving lethal to the cells. To determine a potential mechanism Inductive Coupled Plasma-Mass Spectrometry (ICP-MS) and RNA-seq analysis were performed on zinc exposed cells. Analysis performed on days 4 and 7 indicated that response is dose-dependent, with 10mg/L ZnCl 2 exhibiting nearly all zinc extracellular, corresponding with upregulation of cation transport response. Whereas the 25mg/L ZnCl 2 exhibited half of total zinc sequestered by the cells, which corresponds with the upregulation of sequestering proteins such as metallothionein and the downregulation of genes involved with ATP synthesis and phycobilisome assembly. These analyses were combined with growth monitoring, microscopy, quantitative polymerase chain reaction (qPCR) and flow cytometry to present a full spectrum of mechanisms behind zinc response in S. IU 625. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 60.170 - Applicability and designation of affected facility.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.170 Applicability and designation of affected facility. (a) The...: roaster and sintering machine. (b) Any facility under paragraph (a) of this section that commences...

Uptake and distribution of Zn65 in the coho salmon egg (Oncorhynchus kisutch)

USGS Publications Warehouse

Wedemeyer, Gary

1968-01-01

1. Zinc uptake and distribution in the developing coho salmon egg was measured using radioisotope tracer techniques.2. The uptake was affected by pH, temperature, Cu2+, 2,4-fluorodinitrobenzene and the azo dye, malachite green; but not by azide ion or 2,4-dinitrophenol.3. About 70 per cent of the total accumulated zinc was bound, rather firmly, to the chorion; about 26 per cent was found in the perivitelline fluid, about 2 per cent in the yolk, and about 1 per cent in the embryo.4. Temperature, pH, inhibitor and kinetic studies indicated that zinc uptake involves physicochemical sorption to the chorion together with passive diffusion into the yolk and embryo.

Redox and Lewis acid relay catalysis: a titanocene/zinc catalytic platform in the development of multicomponent coupling reactions.

PubMed

Gianino, Joseph B; Campos, Catherine A; Lepore, Antonio J; Pinkerton, David M; Ashfeld, Brandon L

2014-12-19

A titanocene-catalyzed multicomponent coupling is described herein. Using catalytic titanocene, phosphine, and zinc dust, zinc acetylides can be generated from the corresponding iodoalkynes to affect sequential nucleophilic additions to aromatic aldehydes. The intermediate propargylic alkoxides are trapped in situ with acetic anhydride, which are susceptible to a second nucleophilic displacement upon treatment with a variety of electron-rich species, including acetylides, allyl silanes, electron-rich aromatics, silyl enol ethers, and silyl ketene acetals. Additionally, employing cyclopropane carboxaldehydes led to ring-opened products resulting from iodine incorporation. Taken together, these results form the basis for a new mode of three-component coupling reactions, which allows for rapid access to value added products in a single synthetic operation.

Improved Sp1 and Betaine Homocysteine-S-Methyltransferase Expression and Homocysteine Clearance Are Involved in the Effects of Zinc on Oxidative Stress in High-Fat-Diet-Pretreated Mice.

PubMed

Wu, Li; Zhou, Xihong; Li, Tiejun; He, Juyun; Huang, Linli; Ouyang, Zicheng; He, Liuqin; Wei, Tao; He, Qinghua

2017-12-04

Zinc plays a role in alleviating oxidative stress. However, the related mechanisms remain to be further elucidated. The present study was conducted to investigate whether the recovery of oxidative stress in high-fat-diet (HFD)-pretreated mice was affected by zinc. Male mice received either an HFD or a low-fat-diet (LFD) for 8 weeks. Then, the mice fed with HFD and LFD were both assigned to either a control diet (30 mg zinc, ZD) or a no-added zinc diet (NZD) for an additional 4 weeks. The results showed that after feeding with NZD for 4 weeks, the HFD-pretreated mice had the highest plasma glucose and insulin concentrations, while had the lowest CuZn-SOD and glutathione concentrations. Moreover, after feeding with NZD for 4 weeks, the HFD-pretreated mice had the highest hepatic ROS and homocysteine concentrations, while had the lowest glutathione and methionine concentrations. Furthermore, the HFD-pretreated mice fed with NZD for 4 weeks had the lowest gene and protein expression of betaine homocysteine-S-methyltransferase (BHMT), cystathionine β-synthase, and Sp1. The results suggested that zinc was critical for oxidative stress alleviation and homocysteine clearance in HFD-pretreated mice. It was further elucidated that improved Sp1 and BHMT expression are involved in the effects of zinc on oxidative stress.

A Novel Polyaminocarboxylate Compound To Treat Murine Pulmonary Aspergillosis by Interfering with Zinc Metabolism.

PubMed

Laskaris, Paris; Vicentefranqueira, Rocío; Helynck, Olivier; Jouvion, Grégory; Calera, José Antonio; du Merle, Laurence; Suzenet, Franck; Buron, Frédéric; de Sousa, Rodolphe Alves; Mansuy, Daniel; Cavaillon, Jean-Marc; Latgé, Jean-Paul; Munier-Lehmann, Hélène; Ibrahim-Granet, Oumaima

2018-06-01

Aspergillus fumigatus can cause pulmonary aspergillosis in immunocompromised patients and is associated with a high mortality rate due to a lack of reliable treatment options. This opportunistic pathogen requires zinc in order to grow and cause disease. Novel compounds that interfere with fungal zinc metabolism may therefore be of therapeutic interest. We screened chemical libraries containing 59,223 small molecules using a resazurin assay that compared their effects on an A. fumigatus wild-type strain grown under zinc-limiting conditions and on a zinc transporter knockout strain grown under zinc-replete conditions to identify compounds affecting zinc metabolism. After a first screen, 116 molecules were selected whose inhibitory effects on fungal growth were further tested by using luminescence assays and hyphal length measurements to confirm their activity, as well as by toxicity assays on HeLa cells and mice. Six compounds were selected following a rescreening, of which two were pyrazolones, two were porphyrins, and two were polyaminocarboxylates. All three groups showed good in vitro activity, but only one of the polyaminocarboxylates was able to significantly improve the survival of immunosuppressed mice suffering from pulmonary aspergillosis. This two-tier screening approach led us to the identification of a novel small molecule with in vivo fungicidal effects and low murine toxicity that may lead to the development of new treatment options for fungal infections by administration of this compound either as a monotherapy or as part of a combination therapy. Copyright © 2018 American Society for Microbiology.

Copper and Zinc Deficiency in a Patient Receiving Long-Term Parenteral Nutrition During a Shortage of Parenteral Trace Element Products.

PubMed

Palm, Eric; Dotson, Bryan

2015-11-01

Drug shortages in the United States, including parenteral nutrition (PN) components, have been common in recent years and can adversely affect patient care. Here we report a case of copper and zinc deficiency in a patient receiving PN during a shortage of parenteral trace element products. The management of the patient's deficiencies, including the use of an imported parenteral multi-trace element product, is described. © 2014 American Society for Parenteral and Enteral Nutrition.

Physiological roles of zinc transporters: molecular and genetic importance in zinc homeostasis.

PubMed

Hara, Takafumi; Takeda, Taka-Aki; Takagishi, Teruhisa; Fukue, Kazuhisa; Kambe, Taiho; Fukada, Toshiyuki

2017-03-01

Zinc (Zn) is an essential trace mineral that regulates the expression and activation of biological molecules such as transcription factors, enzymes, adapters, channels, and growth factors, along with their receptors. Zn deficiency or excessive Zn absorption disrupts Zn homeostasis and affects growth, morphogenesis, and immune response, as well as neurosensory and endocrine functions. Zn levels must be adjusted properly to maintain the cellular processes and biological responses necessary for life. Zn transporters regulate Zn levels by controlling Zn influx and efflux between extracellular and intracellular compartments, thus, modulating the Zn concentration and distribution. Although the physiological functions of the Zn transporters remain to be clarified, there is growing evidence that Zn transporters are related to human diseases, and that Zn transporter-mediated Zn ion acts as a signaling factor, called "Zinc signal". Here we describe critical roles of Zn transporters in the body and their contribution at the molecular, biochemical, and genetic levels, and review recently reported disease-related mutations in the Zn transporter genes.

Influence of zinc, lead, and cadmium pollutants on the microflora of hawthorn leaves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bewley, R.J.F.; Campbell, R.

1980-01-01

Transect studies were conducted to determine the relative effects of zinc, lead, and cadmium pollution on microorganisms occurring on hawthorn leaves at varying distances from a smelting complex. Sporobolomyces roseus was absent from the most heavily contaminated leaves but, although lead was inhibitory, other environmental factors were also important in determining its overall population level. Conversely, Aureobasidium pullulans and nonpigmented yeasts showed a significant partial positive correlation with lead but were inhibited by zinc and/or cadmium. Numbers of bacterial colonies were only slightly reduced by the combined effect of all three metals, but total numbers of bacteria were highly negativelymore » correlated with lead. Filamentous fungi, isolated by leaf washing, were only slightly inhibited by all three metals, and the degree of mycelial proliferation on senescent leaves was little affected by heavy metal pollution. Computer-generated maps were produced of the distribution of A. pullulans in relation to zinc and lead fallout. 14 references, 7 figures, 2 tables.« less

Effect of pulse electric fields (PEF) on accumulation of magnesium and zinc ions in Saccharomyces cerevisiae cells.

PubMed

Pankiewicz, Urszula; Sujka, Monika; Włodarczyk-Stasiak, Marzena; Mazurek, Artur; Jamroz, Jerzy

2014-08-15

Cultures of Saccharomyces cerevisiae were treated with PEF to improve simultaneous accumulation of magnesium and zinc ions in the biomass. The results showed that the ions concentration in the medium and their mutual interactions affect accumulation in cells. Increasing the concentration of one ion in the medium reduced the accumulation of the second one, in the control as well as in the cells treated with PEF. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEF of 5.0 kV/cm and 20 μs pulse width, accumulation of magnesium and zinc in yeast biomass reached maximum levels of 2.85 and 11.41 mg/gd.m., respectively, To summarize, optimization of ion pair concentration and PEF parameters caused a 1.5 or 2-fold increase of magnesium and zinc accumulation, respectively, in S. cerevisiae. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of valerian consumption during pregnancy on cortical volume and the levels of zinc and copper in the brain tissue of mouse fetus.

PubMed

Mahmoudian, Alireza; Rajaei, Ziba; Haghir, Hossein; Banihashemian, Shahaboldin; Hami, Javad

2012-04-01

The aim of the present study was to determine the effects of valerian (Valeriana officinalis) consumption in pregnancy on cortical volume and the levels of zinc and copper, two essential elements that affect brain development and function, in the brain tissues of mouse fetuses. Pregnant female mice were treated with either saline or 1.2 g/kg body weight valerian extract intraperitoneally daily on gestation days (GD) 7 to 17. On GD 20, mice were sacrificed and their fetuses were collected. Fetal brains were dissected, weighed and processed for histological analysis. The volume of cerebral cortex was estimated by the Cavalieri principle. The levels of zinc and copper in the brain tissues were measured by atomic absorption spectroscopy. The results indicated that valerian consumption in pregnancy had no significant effect on brain weight, cerebral cortex volume and copper level in fetal brain. However,it significantly decreased the level of zinc in the brain (P<0.05). Using valerian during midgestation do not have an adverse effect on cerebral cortex; however,it caused a significant decrease in zinc level in the fetal brain. This suggests that valerian use should be limited during pregnancy.

Zinc deficiency promotes cystitis-related bladder pain by enhancing function and expression of Cav3.2 in mice.

PubMed

Ozaki, Tomoka; Matsuoka, Junki; Tsubota, Maho; Tomita, Shiori; Sekiguchi, Fumiko; Minami, Takeshi; Kawabata, Atsufumi

2018-01-15

Ca v 3.2 T-type Ca 2+ channel activity is suppressed by zinc that binds to the extracellular histidine-191 of Ca v 3.2, and enhanced by H 2 S that interacts with zinc. Ca v 3.2 in nociceptors is upregulated in an activity-dependent manner. The enhanced Ca v 3.2 activity by H 2 S formed by the upregulated cystathionine-γ-lyase (CSE) is involved in the cyclophosphamide (CPA)-induced cystitis-related bladder pain in mice. We thus asked if zinc deficiency affects the cystitis-related bladder pain in mice by altering Ca v 3.2 function and/or expression. Dietary zinc deficiency for 2 weeks greatly decreased zinc concentrations in the plasma but not bladder tissue, and enhanced the bladder pain/referred hyperalgesia (BP/RH) following CPA at 200mg/kg, a subeffective dose, but not 400mg/kg, a maximal dose, an effect abolished by pharmacological blockade or gene silencing of Ca v 3.2. Acute zinc deficiency caused by systemic N,N,N',N'-tetrakis-(2-pyridylmethyl)-ethylendiamine (TPEN), a zinc chelator, mimicked the dietary zinc deficiency-induced Ca v 3.2-dependent promotion of BP/RH following CPA at 200mg/kg. CPA at 400mg/kg alone or TPEN plus CPA at 200mg/kg caused Ca v 3.2 overexpression accompanied by upregulation of Egr-1 and USP5, known to promote transcriptional expression and reduce proteasomal degradation of Ca v 3.2, respectively, in the dorsal root ganglia (DRG). The CSE inhibitor, β-cyano-l-alanine, prevented the BP/RH and upregulation of Ca v 3.2, Egr-1 and USP5 in DRG following TPEN plus CPA at 200mg/kg. Together, zinc deficiency promotes bladder pain accompanying CPA-induced cystitis by enhancing function and expression of Ca v 3.2 in nociceptors, suggesting a novel therapeutic avenue for treatment of bladder pain, such as zinc supplementation. Copyright © 2017 Elsevier B.V. All rights reserved.

Increased iron bioavailability from lactic-fermented vegetables is likely an effect of promoting the formation of ferric iron (Fe(3+)).

PubMed

Scheers, Nathalie; Rossander-Hulthen, Lena; Torsdottir, Inga; Sandberg, Ann-Sofie

2016-02-01

Lactic fermentation of foods increases the availability of iron as shown in a number of studies throughout the years. Several explanations have been provided such as decreased content of inhibitory phytate, increased solubility of iron, and increased content of lactic acid in the fermented product. However, to our knowledge, there are no data to support that the bioavailability of iron is affected by lactic fermentation. The objective of the present study was to investigate whether the bioavailability of iron from a vegetable mix was affected by lactic fermentation and to propose a mechanism for such an event, by conducting human and cell (Caco-2, HepG2) studies and iron speciation measurements (voltammetry). We also investigated whether the absorption of zinc was affected by the lactic fermentation. In human subjects, we observed that lactic-fermented vegetables served with both a high-phytate and low-phytate meal increased the absorption of iron, but not zinc. In vitro digested fermented vegetables were able to provoke a greater hepcidin response per ng Fe than fresh vegetables, indicating that Fe in the fermented mixes was more bioavailable, independent on the soluble Fe content. We measured that hydrated Fe(3+) species were increased after the lactic fermentation, while there was no significant change in hydrated Fe(2+). Furthermore, lactate addition to Caco-2 cells did not affect ferritin formation in response to Fe nor did lactate affect the hepcidin response in the Caco-2/HepG2 cell system. The mechanism for the increased bioavailability of iron from lactic-fermented vegetables is likely an effect of the increase in ferric iron (Fe(3+)) species caused by the lactic fermentation. No effect on zinc bioavailability was observed.

Zinc ion-induced domain organization in metallo-beta-lactamases: a flexible "zinc arm" for rapid metal ion transfer?

PubMed

Selevsek, Nathalie; Rival, Sandrine; Tholey, Andreas; Heinzle, Elmar; Heinz, Uwe; Hemmingsen, Lars; Adolph, Hans W

2009-06-12

The reversible unfolding of metallo-beta-lactamase from Chryseobacterium meningosepticum (BlaB) by guanidinium hydrochloride is best described by a three-state model including folded, intermediate, and unfolded states. The transformation of the folded apoenzyme into the intermediate state requires only very low denaturant concentrations, in contrast to the Zn2-enzyme. Similarly, circular dichroism spectra of both BlaB and metallo-beta-lactamase from Bacillus cereus 569/H/9 (BcII) display distinct differences between metal-free and Zn2-enzymes, indicating that the zinc ions affect the folding of the proteins, giving a larger alpha-helix content. To identify the regions of the protein involved in this zinc ion-induced change, a hydrogen deuterium exchange study with matrix-assisted laser desorption ionization tandem time of flight mass spectrometry on metal-free and Zn1- and Zn2-BcII was carried out. The region spanning the metal binding metallo-beta-lactamases (MBL) superfamily consensus sequence His-X-His-X-Asp motif and the loop connecting the N- and C-terminal domains of the protein undergoes a zinc ion-dependent structural change between intrinsically disordered and ordered states. The inherent flexibility even appears to allow for the formation of metal ion-bridged protein-protein complexes which may account for both electrospray ionization-mass spectroscopy results obtained upon variation of the zinc/protein ratio and stoichiometry-dependent variations of 199mHg-perturbed angular correlation of gamma-rays spectroscopic data. We suggest that this flexible "zinc arm" motif, present in all the MBL subclasses, is disordered in metal-free MBLs and may be involved in metal ion acquisition from zinc-carrying molecules different from MBL in an "activation on demand" regulation of enzyme activity.

Contribution of Golden Apple Snail Flour to Enhance Omega- 3 and Omega-6 Fatty Acids Contents in Weaning Food

NASA Astrophysics Data System (ADS)

Marsyha, D. D.; Wijayanti, H. S.; Nuryanto; Anjani, G.

2018-02-01

The case of undernourished children in Grobogan District (15.3%) is caused by children nutrients intake less than the Recommendation Dietary Allowance (RDA). To enhance children nutrients intake, be required formulation of weaning food using high-nutrient local food such as golden apple snail (Pomacea canaliculata). Golden apple snail flour contains high contents of zinc, iron, omega-3 and omega-6 fatty acids. This study aims to analyze the effect of golden apple snail flour substitution on nutrients content and organoleptic properties of weaning food (baby porridge). This is an experimental research by substitution of golden apple snail flour in the making of weaning food with four treatments of substitution (0%, 5%, 10%, 15%). Substitution of golden apple snails flour could affect the nutrient content levels of fat, zinc, iron (p=0.0001), carbohydrate (p=0.011), water (p=0.003), ash (p=0.001), omega-3 and omega-6 fatty acids. Whereas, it could not affect the content of energy (p=0.678), protein (p=0.129) and fiber (p=0.482). Furthermore, the substitution could affect the organoleptic properties include color, texture and taste (p=0.0001) while not for the aroma (p=0.798). Based on nutrient content analysis, substitution of golden apple snail flour could enhance the zinc, iron, omega-3 and omega-6 fatty acids contents of weaning food.

Deficient dietary iron intakes among women and children in Russia: evidence from the Russian Longitudinal Monitoring Survey.

PubMed Central

Kohlmeier, L; Mendez, M; Shalnova, S; Martinchik, A; Chakraborty, H; Kohlmeier, M

1998-01-01

OBJECTIVES: This study evaluated the iron sufficiency of the Russian diet. METHODS: Data were obtained from 24-hour dietary recalls conducted in 4 rounds (1992 through 1994) of a nationally representative longitudinal survey of 10,548 women and children. Iron bioavailability was estimated via algorithms adjusting for enhancers (heme, vitamin C) and inhibitors (tannins in tea, phytates in grains) consumed at the same meal. RESULTS: Dietary iron intakes were deficient in the most vulnerable groups: young children and women of reproductive age. Poverty status was strongly associated with deficiency. After adjustment for enhancers and inhibitors, estimated bioavailable iron intakes at 3% to 4% of total iron were inadequate in all women and children. CONCLUSIONS: These dietary data suggest that Russian women and children are at high risk of iron deficiency. Grain products rich in phytates, which inhibit absorption, were the major food source of iron in Russia. High intakes of tea and low consumption of vitamin C also inhibited iron bioavailability. Since changes in eating behavior could potentially double iron bioavailability, educational programs should be explored as a strategy for improving iron nutriture. PMID:9550997

Essentiality of copper in humans.

PubMed

Uauy, R; Olivares, M; Gonzalez, M

1998-05-01

The biochemical basis for the essentiality of copper, the adequacy of the dietary copper supply, factors that condition deficiency, and the special conditions of copper nutriture in early infancy are reviewed. New biochemical and crystallographic evidence define copper as being necessary for structural and catalytic properties of cuproenzymes. Mechanisms responsible for the control of cuproprotein gene expression are not known in mammals; however, studies using yeast as a eukaryote model support the existence of a copper-dependent gene regulatory element. Diets in Western countries provide copper below or in the low range of the estimated safe and adequate daily dietary intake. Copper deficiency is usually the consequence of decreased copper stores at birth, inadequate dietary copper intake, poor absorption, elevated requirements induced by rapid growth, or increased copper losses. The most frequent clinical manifestations of copper deficiency are anemia, neutropenia, and bone abnormalities. Recommendations for dietary copper intake and total copper exposure, including that from potable water, should consider that copper is an essential nutrient with potential toxicity if the load exceeds tolerance. A range of safe intakes should be defined for the general population, including a lower safe intake and an upper safe intake, to prevent deficiency as well as toxicity for most of the population.

Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

PubMed Central

Shi, Xinchang

2017-01-01

Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and energy dispersive spectrometer (EDS). The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1) Zn2+ absorbed on the surface of HA crystal and (2) Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM) results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization. PMID:29159178

The impact of tertiary wastewater treatment on copper and zinc complexation.

PubMed

Constantino, C; Gardner, M; Comber, S D W; Scrimshaw, M D; Ellor, B

2015-01-01

Tightening quality standards for European waters has seen a move towards enhanced wastewater treatment technologies such as granulated organic carbon treatment and ozonation. Although these technologies are likely to be successful in degrading certain micro-organic contaminants, these may also destroy compounds which would otherwise complex and render metals significantly less toxic. This study examined the impact of enhanced tertiary treatment on the capacity of organic compounds within sewage effluents to complex copper and zinc. The data show that granulated organic carbon treatment removes a dissolved organic carbon (DOC) fraction that is unimportant to complexation such that no detrimental impact on complexation or metal bioavailability is likely to occur from this treatment type. High concentrations of ozone (>1 mg O3/mg DOC) are, however, likely to impact the complexation capacity for copper although this is unlikely to be important at the concentrations of copper typically found in effluent discharges or in rivers. Ozone treatment did not affect zinc complexation capacity. The complexation profiles of the sewage effluents show these to contain a category of non-humic ligand that appears unaffected by tertiary treatment and which displays a high affinity for zinc, suggesting these may substantially reduce the bioavailability of zinc in effluent discharges. The implication is that traditional metal bioavailability assessment approaches such as the biotic ligand model may overestimate zinc bioavailability in sewage effluents and effluent-impacted waters.

Short-Term Subclinical Zinc Deficiency in Weaned Piglets Affects Cardiac Redox Metabolism and Zinc Concentration.

PubMed

Brugger, Daniel; Windisch, Wilhelm M

2017-04-01

Background: Subclinical zinc deficiency (SZD) represents the common zinc malnutrition phenotype. However, its association with oxidative stress is not well understood. The heart muscle may be a promising target for studying early changes in redox metabolism. Objective: We investigated the effects of short-term SZD on cardiac redox metabolism in weaned piglets. Methods: Forty-eight weaned German Large White × Landrace × Piétrain piglets (50% castrated males and 50% females; body weight of 8.5 kg) were fed diets with different zinc concentrations for 8 d. Measurements included cardiac parameters of antioxidative capacity, stress-associated gene expression, and tissue zinc status. Analyses comprised (linear, broken-line) regression models and Pearson correlation coefficients. Results: Glutathione and α-tocopherol concentrations as well as catalase, glutathione reductase, B-cell lymphoma 2-associated X protein, and caspase 9 gene expression plateaued in response to reduction in dietary zinc from 88.0 to 57.6, 36.0, 36.5, 41.3, 55.3, and 33.8 mg/kg, respectively ( P < 0.0001). Further reduction in dietary zinc promoted a linear decrease of glutathione and α-tocopherol (30 and 0.6 nmol/mg dietary Zn, respectively; P < 0.05) and a linear increase of gene expression [0.02, 0.01, 0.003, and 0.02 Log 10 (2 -ΔΔCt )/mg dietary Zn, respectively; P < 0.05)]. Tissue zinc declined linearly with reduction in dietary zinc (0.21 mg tissue Zn/mg dietary Zn; P = 0.004) from 88.0 to 42.7 mg/kg ( P < 0.0001), below which it linearly increased inversely to further reduction in dietary zinc (0.57 mg tissue Zn/mg dietary Zn; P = 0.006). H 2 O 2 -detoxification activity and metallothionein 1A gene expression decreased linearly with reduction in dietary zinc from 88.0 to 28.1 mg/kg [0.02 mU and 0.008 Log 10 (2 -ΔΔCt )/mg dietary Zn, respectively; P < 0.05]. Fas cell-surface death receptor, etoposide-induced 2.4 and cyclin-dependent kinase inhibitor 1A gene expression correlated positively to cardiac zinc in piglets fed ≤42.7 mg Zn/kg ( r ≥ 0.97; P < 0.05). Conclusions: Short-term SZD decreased cardiac antioxidative capacity of weaned piglets while simultaneously increasing stress-associated gene expression and zinc concentration. This is the first report to our knowledge on the effects of SZD on redox metabolism. © 2017 American Society for Nutrition.

DETERMINATION OF MATERNAL SERUM ZINC, IRON, CALCIUM AND MAGNESIUM DURING PREGNANCY IN PREGNANT WOMEN AND UMBILICAL CORD BLOOD AND THEIR ASSOCIATION WITH OUTCOME OF PREGNANCY

PubMed Central

Khoushabi, Fahimeh; Shadan, Mohammad Reza; Miri, Ali; Sharifi-Rad, Javad

2016-01-01

Background: Trace elements and specially minerals are critical for the development of fetus. Many minerals are transferred to the fetus for fetal stores in the latter part of the pregnancy. It has been shown that various trace elements such as Zinc, Iron, Calcium and Magnesium are metabolically interrelated and there is alteration in their concentration during pregnancy. Beyond pregnancy is associated with increased demand of all the nutrients and deficiency of any of these could affect pregnancy, delivery and outcome of pregnancy. Aim: To study the levels of trace elements namely zinc, iron, magnesium and calcium in maternal and umbilical cord blood and their association with pregnancy outcome. Methods: Sixty pregnant women in Zabol, Iran were selected from those who had registered their names for the prenatal care and who had followed up till the 3rd trimester of pregnancy ending in child birth. Biochemical parameters analyzed with help of the biochemical laboratory. Data were analyzed by SPSS software. Results: The mean biochemical profile such, serum calcium, magnesium, zinc and iron in the pregnant women were as follow: in the 1st trimester 8.3, 1.9, 74.9 and 74.4 µg/dl respectively; in the 2nd trimester 8.5, 1.9, 73.1 and 79.3 µg/dl, respectively; in the 3rd trimester 8.6, 1.9, 68.4, and 82.2 µg/dl, respectively. In the umbilical cord blood, the mean serum calcium, magnesium, zinc and iron were 8.5, 1.9, 84.1, and 89.8 µg/dl, respectively. The mean serum calcium and magnesium during the three trimesters of pregnancy were not significantly different from that in the umbilical cord blood, while the mean serum zinc and iron in the umbilical cord blood were significantly different (p<0.05) in the three trimester of pregnancy. The mean birth weight of neonates was 3.1 kg and 12% of neonates showed low birth weight. Our findings showed that, except magnesium, the profile of other biochemical variables, namely, calcium, zinc and iron in the umbilical cord blood of the neonates with normal birth weight (NBW) were significantly higher than in the umbilical cord blood of neonates with low birth weight (LBW). Conclusion: The results suggest that maternal serum zinc, iron and calcium concentration influenced the birth weight of neonates as outcome of pregnancy, and however, there is need for proper, adequate and balanced micronutrient during pregnancy to affect neonates as healthy outcome. PMID:27147914

Intracellular zinc flux causes reactive oxygen species mediated mitochondrial dysfunction leading to cell death in Leishmania donovani.

PubMed

Kumari, Anjali; Singh, Krishn Pratap; Mandal, Abhishek; Paswan, Ranjeet Kumar; Sinha, Preeti; Das, Pradeep; Ali, Vahab; Bimal, Sanjiva; Lal, Chandra Shekhar

2017-01-01

Leishmaniasis caused by Leishmania parasite is a global threat to public health and one of the most neglected tropical diseases. Therefore, the discovery of novel drug targets and effective drug is a major challenge and an important goal. Leishmania is an obligate intracellular parasite that alternates between sand fly and human host. To survive and establish infections, Leishmania parasites scavenge and internalize nutrients from the host. Nevertheless, host cells presents mechanism like nutrient restriction to inhibit microbial growth and control infection. Zinc is crucial for cellular growth and disruption in its homeostasis hinders growth and survival in many cells. However, little is known about the role of zinc in Leishmania growth and survival. In this study, the effect of zinc on the growth and survival of L.donovani was analyzed by both Zinc-depletion and Zinc-supplementation using Zinc-specific chelator N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) and Zinc Sulfate (ZnSO4). Treatment of parasites with TPEN rather than ZnSO4 had significantly affected the growth in a dose- and time-dependent manner. The pre-treatment of promastigotes with TPEN resulted into reduced host-parasite interaction as indicated by decreased association index. Zn depletion resulted into flux in intracellular labile Zn pool and increased in ROS generation correlated with decreased intracellular total thiol and retention of plasma membrane integrity without phosphatidylserine exposure in TPEN treated promastigotes. We also observed that TPEN-induced Zn depletion resulted into collapse of mitochondrial membrane potential which is associated with increase in cytosolic calcium and cytochrome-c. DNA fragmentation analysis showed increased DNA fragments in Zn-depleted cells. In summary, intracellular Zn depletion in the L. donovani promastigotes led to ROS-mediated caspase-independent mitochondrial dysfunction resulting into apoptosis-like cell death. Therefore, cellular zinc homeostasis in Leishmania can be explored for new drug targets and chemotherapeutics to control Leishmanial growth and disease progression.

Angiotensin II potentiates zinc-induced cortical neuronal death by acting on angiotensin II type 2 receptor.

PubMed

Park, Mi-Ha; Kim, Ha Na; Lim, Joon Seo; Ahn, Jae-Sung; Koh, Jae-Young

2013-12-01

The angiotensin system has several non-vascular functions in the central nervous system. For instance, inhibition of the brain angiotensin system results in a reduction in neuronal death following acute brain injury such as ischemia and intracerebral hemorrhage, even under conditions of constant blood pressure. Since endogenous zinc has been implicated as a key mediator of ischemic neuronal death, we investigated the possibility that the angiotensin system affects the outcome of zinc-triggered neuronal death in cortical cell cultures. Exposure of cortical cultures containing neurons and astrocytes to 300 μM zinc for 15 min induced submaximal death in both types of cells. Interestingly, addition of angiotensin II significantly enhanced the zinc-triggered neuronal death, while leaving astrocytic cell death relatively unchanged. Both type 1 and 2 angiotensin II receptors (AT1R and AT2R, respectively) were expressed in neurons as well as astrocytes. Zinc neurotoxicity was substantially attenuated by PD123319, a specific inhibitor of AT2R, and augmented by CGP42112, a selective activator of AT2R, indicating a critical role for this receptor subtype in the augmentation of neuronal cell death.Because zinc toxicity occurs largely through oxidative stress, the levels of superoxides in zinc-treated neurons were assessed by DCF fluorescence microscopy. Combined treatment with zinc and angiotensin II substantially increased the levels of superoxides in neurons compared to those induced by zinc alone. This increase in oxidative stress by angiotensin II was completely blocked by the addition of PD123319. Finally, since zinc-induced oxidative stress may be caused by induction and/or activation of NADPH oxidase, the activation status of Rac and the level of the NADPH oxidase subunit p67phox were measured. Angiotensin II markedly increased Rac activity and the levels of p67phox in zinc-treated neurons and astrocytes in a PD123319-dependent manner. The present study shows that the angiotensin system, especially that involving AT2R, may have an oxidative injury-potentiating effect via augmentation of the activity of NADPH oxidase. Hence, blockade of angiotensin signaling cascades in the brain may prove useful in protecting against the oxidative neuronal death that is likely to occur in acute brain injury.

[Vitamin A and zinc levels in gastroenterological surgical patients: Relation with inflammation and postoperative complications].

PubMed

Zago, L B; Danguise, E; González Infantino, C A; Río, M E; Callegari, M

2011-01-01

It is accepted that even mild nutrient depletion may affect the evolution of the surgical patient. To evaluate the influence of preoperative levels of plasma retinol and zinc on postoperative evolution of surgical patients; to evaluate the influence of inflammation on both level markers. Plasma retinol and zinc were determined in 50 patients before programmed gastroenterological surgeries. To detect global malnutrition BMI and weight loss percentage (WL%) were included. C-reactive protein (CRP) was included as inflammation marker. During follow up postoperative complications were recorded. The present analysis was carried out in 43 patients with complete information. Low retinol values (< 20 μg/dl) were founded in 3 cases and low Zn values (< 85 μg/dl) in 20 cases, being 9 of them indicative of severe deficiency (< 70 μg/dl). Postoperative complications were recorded in 17 patients; patients with complications presented lower values of plasma Zn (78.4 ± 25.8 vs. 87.8 ± 25.7 μg/dl) and retinol (36.9 ± 14.5 vs. 49.7 ± 20.6; P = 0.0318) than those with no complications; the number of patients with complications decreased when retinol and Zn ranges increased. No relation between BMI or WL% and appearance of complications was founded; patients with higher WL% were those with higher usual weight. Inflammation affected both markers: retinol dropped from 50.1 ± 17.2 to 44.0 ±20.8 and to 23.7 ± 4.0 μg/dl for CRP ranges of < 0.5, 0.5-3.9 and ≥ 4 mg/dl, respectively (p = 0.0193); levels of zinc fell from 90.1 ± 17.8 to 85.2 ± 29.9 and to 55.0 ± 25.9 μg/dl for the same CRP ranges (P = 0.0195). Zn level influenced retinol level, dropping to 33.1 ± 11.7 μg/dl of retinol in the Zn severe deficiency group (P = 0.0386). The obtained results confirm the influence of vitamin A and zinc on postoperative evolution of the surgical patient, while alert about the interrelationships among vitamin A, zinc and inflammation, which lead to difficulty to establish the real source of deficiencies. Beyond these difficulties, retinol and zinc plasma levels determine the nutrient availability for the body and appear as promissory markers of surgical risk.

Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

PubMed Central

Kim, Ji-Myung; Lee, Ji-Eun; Cho, Mi Sook; Kang, Bong Soo; Choi, Hyeon

2016-01-01

The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth. PMID:26839873

Aging and walnut-rich diet supplementation affects the expression of immediate-early genes in critical brain regions

USDA-ARS?s Scientific Manuscript database

Emerging evidence indicates a direct link between age-associated changes in epigenetic mechanisms and onset of neurodegenerative diseases, and that these genomic modulations are directly affected by diet. Diets deficient in folate, choline and methionine, or the trace elements zinc and selenium, are...

77 FR 56128 - Polyoxin D Zinc Salt; Amendment to an Exemption From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-12

... vegetables, fruiting vegetables, ginseng, grapes, pistachios, pome fruits, potatoes, and strawberries by... to me? You may be potentially affected by this action if you are an agricultural producer, food... whether this document applies to them. Potentially affected entities may include: Crop production (NAICS...

Bovine Leukemia Virus SU Protein Interacts with Zinc, and Mutations within Two Interacting Regions Differently Affect Viral Fusion and Infectivity In Vivo

PubMed Central

Gatot, Jean-Stéphane; Callebaut, Isabelle; Van Lint, Carine; Demonté, Dominique; Kerkhofs, Pierre; Portetelle, Daniel; Burny, Arsène; Willems, Luc; Kettmann, Richard

2002-01-01

Bovine leukemia virus (BLV) and human T-cell lymphotropic virus type 1 (HTLV-1) belong to the genus of deltaretroviruses. Their entry into the host cell is supposed to be mediated by interactions of the extracellular (SU) envelope glycoproteins with cellular receptors. To gain insight into the mechanisms governing this process, we investigated the ability of SU proteins to interact with specific ligands. In particular, by affinity chromatography, we have shown that BLV SU protein specifically interacted with zinc ions. To identify the protein domains involved in binding, 16 peptides distributed along the sequence were tested. Two of them appeared to be able to interact with zinc. To unravel the role of these SU regions in the biology of the virus, mutations were introduced into the env gene of a BLV molecular clone in order to modify residues potentially interacting with zinc. The fusogenic capacity of envelope mutated within the first zinc-binding region (104 to 123) was completely abolished. Furthermore, the integrity of this domain was also required for in vivo infectivity. In contrast, mutations within the second zinc-binding region (218 to 237) did not hamper the fusogenic capacity; indeed, the syncytia were even larger. In sheep, mutations in region 218 to 237 did not alter infectivity or viral spread. Finally, we demonstrated that the envelope of the related HTLV-1 was also able to bind zinc. Interestingly, zinc ions were found to be associated with the receptor-binding domain (RBD) of Friend murine leukemia virus (Fr-MLV) SU glycoprotein, further supporting their relevance in SU structure. Based on the sequence similarities shared with the Fr-MLV RBD, whose three-dimensional structure has been experimentally determined, we located the BLV zinc-binding peptide 104-123 on the opposite side of the potential receptor-binding surface. This observation supports the hypothesis that zinc ions could mediate interactions of the SU RBD either with the C-terminal part of SU, thereby contributing to the SU structural integrity, or with a partner(s) different from the receptor. PMID:12134000

Nitrogen implantation into steel wire coated with zinc used as reinforcement in power transmission conductors

NASA Astrophysics Data System (ADS)

Castro-Maldonado, J. J.; Dulcé-Moreno, H. J.; V-Niño, E. D.

2013-11-01

In tropical environments, diversity of climatic factors such as temperature, relative humidity, deposition of environmental contaminants (such as sulfates and chlorides) affect a large proportion of materials exposed to the weather, and electrochemical corrosion is one of the phenomena that occur in the case of metals and alloys [1, 2]. It is therefore particularly important to study this behavior in the Zinc-coated steel, since this material is used for its economy in the industry specifically in the area of transport of electricity.

Factors that Affect the Content of Cadmium, Nickel, Copper and Zinc in Tissues of the Knee Joint.

PubMed

Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Jakóbik-Kolon, Agata; Kluczka, Joanna; Babuśka-Roczniak, Magdalena

2017-08-01

Osteoarthritis causes the degradation of the articular cartilage and periarticular bones. Trace elements influence the growth, development and condition of the bone tissue. Changes to the mineral composition of the bone tissue can cause degenerative changes and fractures. The aim of the research was to determine the content of cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) in the tibia, the femur and the meniscus in men and women who underwent a knee replacement surgery. Samples were collected from 50 patients, including 36 women and 14 men. The determination of trace elements content were performed by ICP-AES method, using Varian 710-ES. Average concentration in the tissues of the knee joint teeth amounted for cadmium 0.015, nickel 0.60, copper 0.89 and zinc 80.81 mg/kg wet weight. There were statistically significant differences in the content of cadmium, copper and zinc in different parts of the knee joint. There were no statistically significant differences in the content of cadmium, nickel, copper and zinc in women and men in the examined parts of the knee joint. Among the elements tested, copper and nickel showed a high content in the connective tissue (the meniscus) compared to the bone tissue (the tibia and the femur).

Sorption of copper, zinc and cobalt by oat and oat products.

PubMed

Górecka, Danuta; Stachowiak, Jadwiga

2002-04-01

We determined copper, zinc and cobalt sorption by oat and its products under variable pH conditions as well as the content of neutral dietary fiber (NDF) and its fractional composition. Adsorbents in a model sorption system were: oat, dehulled oat, oats bran and oats flakes. Three various buffers (pH 1.8, 6.6 and 8.7) were used as dispersing solutions. Results collected during this study indicate that copper, zinc and cobalt sorption is significantly affected by the type of cereal raw material. Zinc and copper ions are subjected to higher sorption than cobalt ions. Examined metal ions were subjected to high sorption under conditions corresponding to the duodenum environment (pH 8.7), regardless of the kind of adsorbent. A little lower sorption capacity is observed under conditions close to the neutral environment, while the lowest one is found in environment reflecting conditions of stomach juice (pH 1.8). Zinc ions are bound intensively by dehulled oat, while oats flakes bound mostly copper and cobalt, independently on environmental conditions. Contents of dietary fiber in oat, dehulled oat, oat bran and oat flakes were: 40.1, 19.3, 20.3 and 14.3%, respectively. The dominating fraction in all oat products was the fraction of hemicelluloses. The content of remaining fractions varies in dependence on the product.

Zinc oxide nanoparticles as selective killers of proliferating cells

PubMed Central

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant. PMID:21698081

Zinc oxide nanoparticles as selective killers of proliferating cells.

PubMed

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant.

The relationship between zinc intake and growth in children aged 1-8 years: a systematic review and meta-analysis.

PubMed

Stammers, A L; Lowe, N M; Medina, M W; Patel, S; Dykes, F; Pérez-Rodrigo, C; Serra-Majam, L; Nissensohn, M; Moran, V H

2015-02-01

It is estimated that zinc deficiency affects 17% of the world's population, and because of periods of rapid growth children are at an increased risk of deficiency, which may lead to stunting. This paper presents a systematic review and meta-analysis of the randomised controlled trials (RCTs) that assess zinc intake and growth in children aged 1-8 years. This review is part of a larger systematic review by the European Micronutrient Recommendations Aligned Network of Excellence that aims to harmonise the approach to setting micronutrient requirements for optimal health in European populations (www.eurreca.org). Searches were performed of literature published up to and including December 2013 using MEDLINE, Embase and the Cochrane Library databases. Included studies were RCTs in apparently healthy child populations aged from 1 to 8 years that supplied zinc supplements either as capsules or as part of a fortified meal. Pooled meta-analyses were performed when appropriate. Nine studies met the inclusion criteria. We found no significant effect of zinc supplementation of between 2 weeks and 12 months duration on weight gain, height for age, weight for age, length for age, weight for height (WHZ) or WHZ scores in children aged 1-8 years. Many of the children in the included studies were already stunted and may have been suffering from multiple micronutrient deficiencies, and therefore zinc supplementation alone may have only a limited effect on growth.

Combinatorial study of zinc tin oxide thin-film transistors

NASA Astrophysics Data System (ADS)

McDowell, M. G.; Sanderson, R. J.; Hill, I. G.

2008-01-01

Groups of thin-film transistors using a zinc tin oxide semiconductor layer have been fabricated via a combinatorial rf sputtering technique. The ZnO :SnO2 ratio of the film varies as a function of position on the sample, from pure ZnO to SnO2, allowing for a study of zinc tin oxide transistor performance as a function of channel stoichiometry. The devices were found to have mobilities ranging from 2to12cm2/Vs, with two peaks in mobility in devices at ZnO fractions of 0.80±0.03 and 0.25±0.05, and on/off ratios as high as 107. Transistors composed predominantly of SnO2 were found to exhibit light sensitivity which affected both the on/off ratios and threshold voltages of these devices.

SLC30A3 Responds to Glucose- and Zinc Variations in ß-Cells and Is Critical for Insulin Production and In Vivo Glucose-Metabolism During ß-Cell Stress

PubMed Central

Smidt, Kamille; Jessen, Niels; Petersen, Andreas Brønden; Larsen, Agnete; Magnusson, Nils; Jeppesen, Johanne Bruun; Stoltenberg, Meredin; Culvenor, Janetta G.; Tsatsanis, Andrew; Brock, Birgitte; Schmitz, Ole; Wogensen, Lise; Bush, Ashley I.; Rungby, Jørgen

2009-01-01

Background Ion transporters of the Slc30A- (ZnT-) family regulate zinc fluxes into sub-cellular compartments. β-cells depend on zinc for both insulin crystallization and regulation of cell mass. Methodology/Principal Findings This study examined: the effect of glucose and zinc chelation on ZnT gene and protein levels and apoptosis in β-cells and pancreatic islets, the effects of ZnT-3 knock-down on insulin secretion in a β-cell line and ZnT-3 knock-out on glucose metabolism in mice during streptozotocin-induced β-cell stress. In INS-1E cells 2 mM glucose down-regulated ZnT-3 and up-regulated ZnT-5 expression relative to 5 mM. 16 mM glucose increased ZnT-3 and decreased ZnT-8 expression. Zinc chelation by DEDTC lowered INS-1E insulin content and insulin expression. Furthermore, zinc depletion increased ZnT-3- and decreased ZnT-8 gene expression whereas the amount of ZnT-3 protein in the cells was decreased. Zinc depletion and high glucose induced apoptosis and necrosis in INS-1E cells. The most responsive zinc transporter, ZnT-3, was investigated further; by immunohistochemistry and western blotting ZnT-3 was demonstrated in INS-1E cells. 44% knock-down of ZnT-3 by siRNA transfection in INS-1E cells decreased insulin expression and secretion. Streptozotocin-treated mice had higher glucose levels after ZnT-3 knock-out, particularly in overt diabetic animals. Conclusion/Significance Zinc transporting proteins in β-cells respond to variations in glucose and zinc levels. ZnT-3, which is pivotal in the development of cellular changes as also seen in type 2 diabetes (e.g. amyloidosis in Alzheimer's disease) but not previously described in β-cells, is present in this cell type, up-regulated by glucose in a concentration dependent manner and up-regulated by zinc depletion which by contrast decreased ZnT-3 protein levels. Knock-down of the ZnT-3 gene lowers insulin secretion in vitro and affects in vivo glucose metabolism after streptozotocin treatment. PMID:19492079

Factors Affecting the Tunneling Behavior of the Western Subterranean Termite, Reticulitermes Hesperus Banks

Treesearch

James L. Smith; Michael K. Rust

1991-01-01

Laboratory studies were conducted to determine factors that affect the tunneling behavior of the western subterranean termite (Reticulitermes hesperus Banks). Soil particle sizes between 2.36 and 0.84 mm prevented tunneling. Exposure to solid layers of calcium, magnesium, or zinc borate did not repel workers, but produced >87 percent kill...

Iron, copper, and zinc status: response to supplementation with zinc or zinc and iron in adult females.

PubMed

Yadrick, M K; Kenney, M A; Winterfeldt, E A

1989-01-01

Response of iron, copper, and zinc status to supplementation with Zn or a combination of Zn and Fe was assessed in adult females in a 10-wk study. Group Z received 50 mg Zn/d as Zn gluconate; group F-Z received 50 mg Fe as ferrous sulfate monohydrate in addition to the Zn. For Group Z, serum ferritin, hematocrit, and erythrocyte Cu,Zn-superoxide dismutase (ESOD) were significantly lower (p less than 0.05) after 10 wk supplementation compared with pretreatment levels. Serum Zn increased (p less than 0.01) but no change occurred in serum ceruloplasmin, hemoglobin, or salivary sediment Zn with treatment. For Group F-Z ESOD decreased with treatment as did salivary sediment Zn (p less than 0.05). Serum ferritin and serum Zn increased significantly, but hemoglobin, hematocrit, and ceruloplasmin were not affected by this treatment. Supplementation with Zn poses a risk to Fe and Cu status. Inclusion of Fe with Zn ameliorates the effect on Fe but not on Cu status.

Effect of NaFeEDTA-fortified soy sauce on zinc absorption in children.

PubMed

Li, Min; Wu, Jinghuan; Ren, Tongxiang; Wang, Rui; Li, Weidong; Piao, Jianhua; Wang, Jun; Yang, Xiaoguang

2015-03-01

NaFeEDTA has been applied in many foods as an iron fortificant and is used to prevent iron deficiency in Fe-depleted populations. In China, soy sauce is fortified with NaFeEDTA to control iron deficiency. However, it is unclear whether Fe-fortified soy sauce affects zinc absorption. To investigate whether NaFeEDTA-fortified soy sauce affects zinc absorption in children, sixty children were enrolled in this study and randomly assigned to three groups (10 male children and 10 female children in each group). All children received daily 3 mg of (67)Zn and 1.2 mg of dysprosium orally, while the children in the three groups were supplemented with NaFeEDTA-fortified soy sauce (6 mg Fe, NaFeEDTA group), FeSO₄-fortified soy sauce (6 mg Fe, FeSO₄ group), and no iron-fortified soy sauce (control group), respectively. Fecal samples were collected during the experimental period and analyzed for the Zn content, (67)Zn isotope ratio and dysprosium content. The Fe intake from NaFeEDTA-fortified and FeSO₄-fortified groups was significantly higher than that in the control group (P < 0.0001). The daily total Zn intake was not significantly different among the three groups. There were no significant differences in fractional Zn absorption (FZA) (P = 0.3895), dysprosium recovery (P = 0.7498) and Zn absorption (P = 0.5940) among the three groups. Therefore, NaFeEDTA-fortified soy sauce does not affect Zn bioavailability in children.

Effects of sediment-bound zinc contamination on early life stages of the mummichog (Fundulus heteroclitus L.) in the Christina watershed, Delaware, U.S.A.

PubMed

Guy, Christopher Paul; Pinkney, Alfred Eli; Taylor, Malcolm Herbert

2006-05-01

During the last century, the Christina River, the major estuarine river system in New Castle County (DE, USA), has received loadings of organic and inorganic chemicals, primarily from manufacturing facilities. Among the most abundant chemicals is zinc, which has accumulated in sediments at concentrations as high as 5,440 mg/kg. We studied the possible effects of zinc on early life stages of the mummichog (Fundulus heteroclitus), a resident species in the river and watershed. We conducted three different types of exposures. The first was a 96-h median lethal concentration (LC50) test with larvae exposed to waterborne zinc. The second was a larval exposure with zinc-spiked sediments (obtained from the relatively uncontaminated Magothy River in Anne Arundel County, MD, USA). The third was an embryo-larval exposure with Christina River sediments having a gradient of zinc concentrations. The average 96-h LC50 with newly hatched yolk sac larvae was 970 lig/L. In the larval tests, the average 7- and 21-d LC50s were 1154 and 1012 mg/kg, respectively. In the embryo-larval test, no significant difference was found in survival at concentrations between 38.8 and 1098 mg/kg. However, significant reductions were observed in condition factor at concentrations of 582, 799, and 1098 mg/kg. We calculated an average no-observed-effects concentration of 579 mg/kg and an average lowest-observed-effects concentration of 849 mg/kg for larval survival. Based on these results, we suggest that zinc in the Christina River may be affecting early life stages of the mummichog.

Effects of zinc-fortified drinking skim milk (as functional food) on cytokine release and thymic hormone activity in very old persons: a pilot study.

PubMed

Costarelli, Laura; Giacconi, Robertina; Malavolta, Marco; Basso, Andrea; Piacenza, Francesco; DeMartiis, MariLuisa; Giannandrea, Elvio; Renieri, Carlo; Busco, Franco; Galeazzi, Roberta; Mocchegiani, Eugenio

2014-06-01

Zinc is a relevant nutritional factor for the whole life of an organism because it affects the inflammatory/immune response and antioxidant activity, leading to a healthy state. Despite its important function, the dietary intake of zinc is inadequate in elderly. Possible interventions include food fortification because it does not require changes in dietary patterns, the cost is low and it can reach a large portion of the elderly population, including very old subjects. Studies evaluating the impact of Zn-fortified foods on functional parameters in elderly, in particular, in very old individuals, are missing. The objective of this study was to evaluate the efficacy of consumption of a zinc-fortified drinking skim milk (Zn-FMilk) for a period of 2 months in comparison to standard non-fortified milk (No-FMilk) on some biochemical parameters, zinc status, inflammatory/immune response and on a key parameter of the T cell-mediated immunity (thymulin hormone) in healthy very old subjects. The treatment with zinc-fortified milk (Zn-FMilk) is a good omen to increase the cell-mediated immunity in very old age represented by thymulin activity and some cytokine (IL-12p70, IFN-γ) release. At clinical level, a good healthy state occurs in 70 % of the subjects with no hospitalization after 1 year of the follow-up in comparison to very old control subjects that did not participate to crossover design. In conclusion, the Zn-FMilk can be considered a good functional food for elderly, including older people. It might be a good replacement to the zinc tablets or lozenges taking into account the attitude of old people to uptake milk as a preferential food.

Leptin, neuropeptide Y (NPY), melatonin and zinc levels in experimental hypothyroidism and hyperthyroidism: relation with melatonin and the pineal gland.

PubMed

Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

2018-03-02

Background Melatonin, an important neurohormone released from the pineal gland, is generally accepted to exercise an inhibitor effect on the thyroid gland. Zinc mediates the effects of many hormones and is found in the structure of numerous hormone receptors. Aim The present study aims to examine the effect of melatonin supplementation and pinealectomy on leptin, neuropeptide Y (NPY), melatonin and zinc levels in rats with hypothyroidism and hyperthyroidism. Methods This study was performed on the 70 male rats. Experimental animals in the study were grouped as follows: control (C); hypothyroidism (PTU); hypothyroidism + melatonin (PTU + M); hypothyroidism + pinealectomy (PTU + Pnx); hyperthyroidism (H); hyperthyroidism + melatonin (H + M) and hyperthyroidism + pinealectomy (H + Pnx). Blood samples collected at the end of 4-week procedures were analyzed to determine melatonin, leptin, NPY and zinc levels. Results It was found that thyroid parameters thyroid stimulating hormone (TSH), free triiodthyronine (FT3), free thyroxine (FT4), total T3 (TT3) and total T4 (TT4) decreased in hypothyroidism groups and increased in the groups with hyperthyroidism. The changes in these hormones remained unaffected by melatonin supplementation and pinealectomy. Melatonin levels rose in hyperthyroidism and fell in hypothyroidism. Leptin and NPY levels increased in both hypothyroidism and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and pinealectomy, but increased in hyperthyroidism. Conclusion The results of the study demonstrate that hypothyroidism and hyperthyroidism affect leptin, NPY, melatonin and zinc values in different ways in rats. However, melatonin supplementation and pinealectomy do not have any significant influence on the changes occurring in leptin, NPY and zinc levels in thyroid dysfunction.

Effect of different spiking procedures on the distribution and toxicity of ZnO nanoparticles in soil.

PubMed

Waalewijn-Kool, Pauline L; Diez Ortiz, Maria; van Gestel, Cornelis A M

2012-10-01

Due to the difficulty in dispersing some engineered nanomaterials in exposure media, realizing homogeneous distributions of nanoparticles (NP) in soil may pose major challenges. The present study investigated the distribution of zinc oxide (ZnO) NP (30 nm) and non-nano ZnO (200 nm) in natural soil using two different spiking procedures, i.e. as dry powder and as suspension in soil extract. Both spiking procedures showed a good recovery (>85 %) of zinc and based on total zinc concentrations no difference was found between the two spiking methods. Both spiking procedures resulted in a fairly homogeneous distribution of the ZnO particles in soil, as evidenced by the low variation in total zinc concentration between replicate samples (<12 % in most cases). Survival of Folsomia candida in soil spiked at concentrations up to 6,400 mg Zn kg(-1) d.w. was not affected for both compounds. Reproduction was reduced in a concentration-dependent manner with EC50 values of 3,159 and 2,914 mg Zn kg(-1) d.w. for 30 and 200 nm ZnO spiked as dry powder and 3,593 and 5,633 mg Zn kg(-1) d.w. introduced as suspension. Toxicity of ZnO at 30 and 200 nm did not differ. We conclude that the ZnO particle toxicity is not size related and that the spiking of the soil with ZnO as dry powder or as a suspension in soil extract does not affect its toxicity to F. candida.

Apparent mineral retention is similar in control and hyperinsulinemic men after consumption of high amylose cornstarch.

PubMed

Behall, Kay M; Howe, Juliette C; Anderson, Richard A

2002-07-01

The effects on apparent mineral retention after long-term consumption of a high amylose diet containing 30 g resistant starch (RS) were investigated in 10 control and 14 hyperinsulinemic men. Subjects consumed products (bread, muffins, cookies, corn flakes and cheese puffs) made with standard (70% amylopectin, 30% amylose; AP) or high amylose (70% amylose, 30% amylopectin; AM) cornstarch for two 14-wk periods in a crossover pattern. Starch products replaced usual starches in the habitual diet for 10 wk followed by 4 wk of consuming the controlled diets. During wk 12, all urine, feces and duplicate foods were collected for 7 d. Urinary chromium losses after a glucose tolerance test or 24-h collections of the hyperinsulinemic and control subjects did not differ and were not altered by diet. Except for zinc, the two subject types did not differ significantly in apparent mineral balance. Apparent retentions of calcium and magnesium were not significantly affected by diet (AM vs. AP) or type-by-diet interaction. Apparent iron retention tended to be greater after AM than AP consumption (P < 0.09). Apparent copper retention was greater after consuming AP than after AM (P < 0.02), whereas apparent zinc retention was greater after consuming AM than after AP (P < 0.018). Zinc also showed a significant type-by-diet interaction (P < 0.034) with control subjects retaining less zinc after consuming AP than after AM. In summary, a high amylose cornstarch diet containing 30 g RS could be consumed long term without markedly affecting, and possibly enhancing, retention of some minerals.

Rhizosphere Microbial Community Composition Affects Cadmium and Zinc Uptake by the Metal-Hyperaccumulating Plant Arabidopsis halleri

PubMed Central

Muehe, E. Marie; Weigold, Pascal; Adaktylou, Irini J.; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas

2015-01-01

The remediation of metal-contaminated soils by phytoextraction depends on plant growth and plant metal accessibility. Soil microorganisms can affect the accumulation of metals by plants either by directly or indirectly stimulating plant growth and activity or by (im)mobilizing and/or complexing metals. Understanding the intricate interplay of metal-accumulating plants with their rhizosphere microbiome is an important step toward the application and optimization of phytoremediation. We compared the effects of a “native” and a strongly disturbed (gamma-irradiated) soil microbial communities on cadmium and zinc accumulation by the plant Arabidopsis halleri in soil microcosm experiments. A. halleri accumulated 100% more cadmium and 15% more zinc when grown on the untreated than on the gamma-irradiated soil. Gamma irradiation affected neither plant growth nor the 1 M HCl-extractable metal content of the soil. However, it strongly altered the soil microbial community composition and overall cell numbers. Pyrosequencing of 16S rRNA gene amplicons of DNA extracted from rhizosphere samples of A. halleri identified microbial taxa (Lysobacter, Streptomyces, Agromyces, Nitrospira, “Candidatus Chloracidobacterium”) of higher relative sequence abundance in the rhizospheres of A. halleri plants grown on untreated than on gamma-irradiated soil, leading to hypotheses on their potential effect on plant metal uptake. However, further experimental evidence is required, and wherefore we discuss different mechanisms of interaction of A. halleri with its rhizosphere microbiome that might have directly or indirectly affected plant metal accumulation. Deciphering the complex interactions between A. halleri and individual microbial taxa will help to further develop soil metal phytoextraction as an efficient and sustainable remediation strategy. PMID:25595759

The effects of coadministration of dietary copper and zinc supplements on atherosclerosis, antioxidant enzymes and indices of lipid peroxidation in the cholesterol-fed rabbit

PubMed Central

Alissa, Eman M; Bahijri, Suhad M; Lamb, David J; Ferns, Gordon A A

2004-01-01

It has previously been shown that dietary copper can modulate the extent of atherosclerosis in the thoracic aorta of cholesterol-fed rabbits. The metabolism of copper and zinc are closely related, and it has been hypothesized that the balance of dietary copper to zinc may be important in determining coronary risk. Hence, we have investigated the interaction between dietary copper and zinc in atherogenesis in the New Zealand White rabbit. Juvenile male rabbits were randomly allocated to eight groups. Four groups were fed a normal chow diet with zinc (0.5%, w/w), copper (0.2%, w/w), copper plus zinc or neither in their drinking water for 12 weeks. Four other groups were fed a diet containing 0.25–1% (w/w) cholesterol plus zinc, copper, both or neither. Serum cholesterol of individual animals was maintained at approximately 20 mmol/l. Integrated plasma cholesterol levels were similar for all groups receiving cholesterol and significantly higher than those in the chow-fed groups (P < 0.001). Aortic copper concentrations were higher in the animals receiving cholesterol diets with copper compared to rabbits receiving normal chow and copper (P < 0.001). Aortic zinc content was significantly higher in cholesterol-fed rabbits supplemented with zinc alone or with copper than in those fed cholesterol alone (P < 0.001). Plasma ceruloplasmin concentrations were significantly higher in groups receiving cholesterol, irrespective of their trace element supplementation (P < 0.001). However, trace element supplementation increased the level significantly (P < 0.05). Trace element supplements did not appear to affect erythrocyte superoxide dismutase in the cholesterol-fed animals; however, zinc supplementation was associated with a significant increase in the enzyme in chow-fed animals (P < 0.05). The activity of the enzyme per mg of protein in aortic tissue was higher in animals receiving copper in the presence of cholesterol (P < 0.05) but not significantly so in its absence. Dietary trace element supplementation in cholesterol-fed animals was associated with a significant reduction in aortic lesion area. Plasma thiobarbituric acid-reactive substances and FOX concentrations were both significantly higher in the cholesterol-fed rabbits compared with the animals that fed on a chow diet (P < 0.001), and these were reduced significantly by dietary copper or zinc supplementation (P < 0.001). Hence, dietary supplements of copper or zinc at the doses used both inhibited aortic atherogenesis in the cholesterol-fed rabbits, although there was no significant additional effect when given in combination. PMID:15379959

The Hypolipidemic and Pleiotropic Effects of Rosuvastatin Are Not Enhanced by Its Association with Zinc and Selenium Supplementation in Coronary Artery Disease Patients: A Double Blind Randomized Controlled Study

PubMed Central

Sena-Evangelista, Karine Cavalcanti Maurício; Pedrosa, Lucia Fatima Campos; Paiva, Maria Sanali Moura Oliveira; Dias, Paula Cristina Silveira; Ferreira, Diana Quitéria Cabral; Cozzolino, Sílvia Maria Franciscato; Faulin, Tanize Espírito Santo; Abdalla, Dulcinéia Saes Parra

2015-01-01

Objective Statins treatment may modify the levels of zinc and selenium, minerals that can improve vascular function and reduce oxidative damage and inflammation in atherosclerotic patients. This study aimed to evaluate the effects of rosuvastatin, alone or associated with zinc and selenium supplementation, on lipid profile, antioxidant enzymes and mineral status in coronary artery disease patients. Material and Methods A double-blind randomized clinical trial was performed in which patients (n = 76) were treated with 10 mg rosuvastatin over 4 months associated or not with zinc (30 mg/d) and selenium (150 μg/d) supplementation. The following parameters were analyzed before and after the intervention: anthropometric measurements, lipid profile, high sensitivity C-reactive protein (hs-CRP), electronegative low density lipoprotein (LDL(-)) concentrations, activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), zinc and selenium concentrations in blood plasma and erythocytes. Significance was determined using an α of 5% (two-tailed). Results We found that rosuvastatin therapy was efficient in reducing total cholesterol, LDL-cholesterol, non-HDL cholesterol, triglycerides, and hs-CRP independently of mineral supplementation. Neither treatment was associated with significant changes in LDL(-). Similarly, the antioxidant enzymes GPx and SOD activity were unchanged by treatments. Neither treatment was associated with significant differences in concentrations of zinc or selenium in blood plasma and erythocytes of studied groups. Conclusion Rosuvastatin treatment did not affect zinc and selenium levels in coronary artery disease patients. The zinc and selenium supplementation at doses used in this study did not change lipid profile or SOD and GPx activity in patients receiving rosuvastatin. Further studies should be focused on testing alternative doses and supplements in different populations to contribute for a consensus on the ideal choice of antioxidants to be used as possible complementary therapies in atherosclerotic patients. Trial Registration ClinicalTrials.gov NCT01547377 PMID:25785441

Zinc Supplementation Does Not Alter Indicators of Insulin Secretion and Sensitivity in Black and White Female Adolescents.

PubMed

Lobene, Andrea J; Kindler, Joseph M; Jenkins, Nathan T; Pollock, Norman K; Laing, Emma M; Grider, Arthur; Lewis, Richard D

2017-07-01

Background: Zinc is a micronutrient involved in the production of, and peripheral sensitivity to, pancreatic β cell-derived insulin. To our knowledge, the effect of zinc supplementation on insulin outcomes, and potential risk of diabetes, in otherwise healthy children in the United States has not been investigated. Objective: The objective of this study was to determine the influence of zinc supplementation on insulin outcomes in black and white girls in the early stages of adolescence. A secondary objective was to determine relations between baseline zinc concentrations and insulin outcomes. Methods: Healthy black and white girls aged 9-11 y were randomly assigned to daily supplementation of zinc (9 mg elemental Zn/d; n = 75; blacks: n = 35) or placebo ( n = 72; blacks: n = 32) for 4 wk. Fasting serum insulin, glucose, and C-peptide were assessed at baseline and at 4 wk. C-peptide and glucose values were used to calculate the computer model-derived homeostatic model assessment of insulin resistance (HOMA2-IR). Changes in outcome measures were compared by using repeated-measures, mixed-model ANOVA. Results: Baseline plasma zinc was not correlated with C-peptide ( r = -0.07), insulin ( r = -0.06), or HOMA2-IR ( r = -0.09) (all P > 0.05) after controlling for race and age. Treatment × time interactions for C-peptide and HOMA2-IR were not significant (both P > 0.05). Although the treatment × race × time interactions for C-peptide and HOMA2-IR were not significant (both P = 0.08), black girls who received the placebo experienced slight increases in C-peptide (15.7%) and HOMA2-IR (17.7%) ( P = 0.06). Conclusions: Four weeks of zinc supplementation had no effect on insulin outcomes in healthy black and white early-adolescent girls, although C-peptide and HOMA2-IR tended to increase in black girls who received placebo. Additional trials that are appropriately powered should further explore the effect of zinc on markers of diabetes risk, and whether race affects this relation. This trial was registered at clinicaltrials.gov as NCT01892098. © 2017 American Society for Nutrition.

Zinc and volatile element loss during planetary magma ocean phases

NASA Astrophysics Data System (ADS)

Dhaliwal, Jasmeet K.; Day, James M. D.; Moynier, Frédéric

2016-10-01

Zinc is a moderately volatile element and a key tracer of volatile depletion on planetary bodies due to lack of significant isotopic fractionation under high-temperature processes. Terrestrial basalts have δ66Zn values similar to some chondrites (+ 0.15 to 0.3‰ where [{66Zn/64Znsample/66Zn/64ZnJMC-Lyon-1} × 1000]) and elevated Zn concentrations (100 ppm). Lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ and have low Zn concentrations (~2 ppm). Late-stage lunar magmatic products, such as ferroan anorthosite, Mg-suite and Alkali suite rocks exhibit heavier δ66Zn values (+3 to +6‰). The heavy δ66Zn lunar signature is thought to reflect evaporative loss and fractionation of zinc, either during a giant impact or in a magma ocean phase.We explore conditions of volatile element loss within a lunar magma ocean (LMO) using models of Zn isotopic fractionation that are widely applicable to planetary magma oceans. For the Moon, our objective was to identify conditions that would yield a δ66Zn signature of ~ +1.4‰ within the mantle, assuming a terrestrial mantle zinc starting composition.We examine two cases of zinc evaporative fractionation: (1) lunar surface zinc fractionation that was completed prior to LMO crystallization and (2) lunar surface zinc fractionation that was concurrent with LMO crystallization. The first case resulted in a homogeneous lunar mantle and the second case yielded a stratified lunar mantle, with the greatest zinc isotopic enrichment in late-stage crystallization products. This latter case reproduces the distribution of zinc isotope compositions in lunar materials quite well.We find that hydrodynamic escape was not a dominant process in losing Zn, but that erosion of a nascent lunar atmosphere, or separation of condensates into a proto-lunar crust are possible. While lunar volatile depletion is still possible as a consequence of the giant impact, this process cannot reproduce the variable δ66Zn found in the Moon. Outgassing during magma ocean phases would have led to volatile-depleted planetesimal feed-stocks that would have profoundly affected the ultimate volatile inventories of larger planetary bodies.

Effects of Alder Mine on the Water, Sediments, and Benthic Macroinvertebrates of Alder Creek, 1998 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peplow, Dan

1999-05-28

The Alder Mine, an abandoned gold, silver, copper, and zinc mine in Okanogan County, Washington, produces heavy metal-laden effluent that affects the quality of water in a tributary of the Methow River. The annual mass loading of heavy metals from two audits at the Alder Mine was estimated to exceed 11,000 kg per year. In this study, water samples from stations along Alder Creek were assayed for heavy metals by ICP-AES and were found to exceed Washington State's acute freshwater criteria for cadmium (Cd), copper (Cu), selenium (Se), and zinc (Zn).

Study on copper kinetics in processing sulphide ore mixed with copper and zinc with sulfuric acid leaching under pressure

NASA Astrophysics Data System (ADS)

Wen-bo, LUO; Ji-kun, WANG; Yin, GAN

2018-01-01

Sulphide ore mixed with copper and zinc is processed with pressure acid leaching. Research is conducted on the copper kinetic. The stirring rate is set at 600 rpm which could eliminate the influence of external diffusions. Research is conducted on the factors affecting the copper leaching kinetic are temperature, pressure, concentration of sulfuric acid, particle size. The result shows that the apparent activity energy is 50.7 KJ/mol. We could determine that the copper leaching process is shrinking core model of chemical reaction control and work out the leaching equation.

Stability of Cucumber Necrosis Virus at the Quasi-6-Fold Axis Affects Zoospore Transmission.

PubMed

Sherman, Michael B; Kakani, Kishore; Rochon, D'Ann; Jiang, Wen; Voss, Neil R; Smith, Thomas J

2017-10-01

Cucumber necrosis virus (CNV) is a member of the genus Tombusvirus and has a monopartite positive-sense RNA genome. CNV is transmitted in nature via zoospores of the fungus Olpidium bornovanus As with other members of the Tombusvirus genus, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507-517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). P73 lies immediately adjacent to a putative zinc binding site (M. Li et al., J Virol 87:12166-12175, 2013, https://doi.org/10.1128/JVI.01965-13) that is formed by three icosahedrally related His residues in the N termini of the C subunit at the quasi-6-fold axes. To better understand how this buried residue might affect vector transmission, we determined the cryo-electron microscopy structure of wild-type CNV in the native and swollen state and of the transmission-defective mutant, P73G, under native conditions. With the wild-type CNV, the swollen structure demonstrated the expected expansion of the capsid. However, the zinc binding region at the quasi-6-fold at the β-annulus axes remained intact. By comparison, the zinc binding region of the P73G mutant, even under native conditions, was markedly disordered, suggesting that the β-annulus had been disrupted and that this could destabilize the capsid. This was confirmed with pH and urea denaturation experiments in conjunction with electron microscopy analysis. We suggest that the P73G mutation affects the zinc binding and/or the β-annulus, making it more fragile under neutral/basic pH conditions. This, in turn, may affect zoospore transmission. IMPORTANCE Cucumber necrosis virus (CNV), a member of the genus Tombusvirus , is transmitted in nature via zoospores of the fungus Olpidium bornovanus While a number of plant viruses are transmitted via insect vectors, little is known at the molecular level as to how the viruses are recognized and transmitted. As with many spherical plant viruses, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation that lies inside the capsid immediately adjacent to a putative zinc binding site (Li et al., J Virol 87:12166-12175, 2013, https://doi.org/10.1128/JVI.01965-13) blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507-517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). Here, we show that the P73G mutant is less stable than the wild type, and this appears to be correlated with destabilization of the β-annulus at the icosahedral 3-fold axes. Therefore, the β-annulus appears not to be essential for particle assembly but is necessary for interactions with the transmission vector. Copyright © 2017 American Society for Microbiology.

Stability of Cucumber Necrosis Virus at the Quasi-6-Fold Axis Affects Zoospore Transmission

PubMed Central

Sherman, Michael B.; Kakani, Kishore; Rochon, D'Ann; Jiang, Wen; Voss, Neil R.

2017-01-01

ABSTRACT Cucumber necrosis virus (CNV) is a member of the genus Tombusvirus and has a monopartite positive-sense RNA genome. CNV is transmitted in nature via zoospores of the fungus Olpidium bornovanus. As with other members of the Tombusvirus genus, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507–517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). P73 lies immediately adjacent to a putative zinc binding site (M. Li et al., J Virol 87:12166–12175, 2013, https://doi.org/10.1128/JVI.01965-13) that is formed by three icosahedrally related His residues in the N termini of the C subunit at the quasi-6-fold axes. To better understand how this buried residue might affect vector transmission, we determined the cryo-electron microscopy structure of wild-type CNV in the native and swollen state and of the transmission-defective mutant, P73G, under native conditions. With the wild-type CNV, the swollen structure demonstrated the expected expansion of the capsid. However, the zinc binding region at the quasi-6-fold at the β-annulus axes remained intact. By comparison, the zinc binding region of the P73G mutant, even under native conditions, was markedly disordered, suggesting that the β-annulus had been disrupted and that this could destabilize the capsid. This was confirmed with pH and urea denaturation experiments in conjunction with electron microscopy analysis. We suggest that the P73G mutation affects the zinc binding and/or the β-annulus, making it more fragile under neutral/basic pH conditions. This, in turn, may affect zoospore transmission. IMPORTANCE Cucumber necrosis virus (CNV), a member of the genus Tombusvirus, is transmitted in nature via zoospores of the fungus Olpidium bornovanus. While a number of plant viruses are transmitted via insect vectors, little is known at the molecular level as to how the viruses are recognized and transmitted. As with many spherical plant viruses, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation that lies inside the capsid immediately adjacent to a putative zinc binding site (Li et al., J Virol 87:12166–12175, 2013, https://doi.org/10.1128/JVI.01965-13) blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507–517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). Here, we show that the P73G mutant is less stable than the wild type, and this appears to be correlated with destabilization of the β-annulus at the icosahedral 3-fold axes. Therefore, the β-annulus appears not to be essential for particle assembly but is necessary for interactions with the transmission vector. PMID:28724762

Modulating the Intrinsic Disorder in the Cytoplasmic Domain Alters the Biological Activity of the N-Methyl-d-aspartate-sensitive Glutamate Receptor*

PubMed Central

Choi, Ucheor B.; Kazi, Rashek; Stenzoski, Natalie; Wollmuth, Lonnie P.; Uversky, Vladimir N.; Bowen, Mark E.

2013-01-01

The NMDA-sensitive glutamate receptor is a ligand-gated ion channel that mediates excitatory synaptic transmission in the nervous system. Extracellular zinc allosterically regulates the NMDA receptor by binding to the extracellular N-terminal domain, which inhibits channel gating. Phosphorylation of the intrinsically disordered intracellular C-terminal domain alleviates inhibition by extracellular zinc. The mechanism for this functional effect is largely unknown. Proline is a hallmark of intrinsic disorder, so we used proline mutagenesis to modulate disorder in the cytoplasmic domain. Proline depletion selectively uncoupled zinc inhibition with little effect on receptor biogenesis, surface trafficking, or ligand-activated gating. Proline depletion also reduced the affinity for a PDZ domain involved in synaptic trafficking and affected small molecule binding. To understand the origin of these phenomena, we used single molecule fluorescence and ensemble biophysical methods to characterize the structural effects of proline mutagenesis. Proline depletion did not eliminate intrinsic disorder, but the underlying conformational dynamics were changed. Thus, we altered the form of intrinsic disorder, which appears sufficient to affect the biological activity. These findings suggest that conformational dynamics within the intrinsically disordered cytoplasmic domain are important for the allosteric regulation of NMDA receptor gating. PMID:23782697

Plant architecture and grain yield are regulated by the novel DHHC-type zinc finger protein genes in rice (Oryza sativa L.).

PubMed

Zhou, Bo; Lin, Jian Zhong; Peng, Dan; Yang, Yuan Zhu; Guo, Ming; Tang, Dong Ying; Tan, Xiaofeng; Liu, Xuan Ming

2017-01-01

In many plants, architecture and grain yield are affected by both the environment and genetics. In rice, the tiller is a vital factor impacting plant architecture and regulated by many genes. In this study, we cloned a novel DHHC-type zinc finger protein gene Os02g0819100 and its alternative splice variant OsDHHC1 from the cDNA of rice (Oryza sativa L.), which regulate plant architecture by altering the tiller in rice. The tillers increased by about 40% when this type of DHHC-type zinc finger protein gene was over-expressed in Zhong Hua 11 (ZH11) rice plants. Moreover, the grain yield of transgenic rice increased approximately by 10% compared with wild-type ZH11. These findings provide an important genetic engineering approach for increasing rice yields. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of sulfur, zinc, iron, copper, manganese, and boron applications on sunflower yield and plant nutrient concentration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hilton, B.R.; Zubriski, J.C.

1985-01-01

Sulfur, zinc, iron, copper, manganese, and boron application did not affect the seed yield or oil percentage of sunflower (Helianthus annuus L.) on both dryland and irrigated soils in North Dakota in 1981. Field averages indicated significant Zn, Mn, and B uptake by sunflower at the 12-leaf stage as a result of fertilization with these elements. Increased Zn uptake was also observed in the uppermost mature leaf at anthesis from zinc fertilization. Although sunflower yield from boron fertilization was not significantly different from the check, a trend was observed in which boron fertilization seemed to decrease sunflower yield. Sunflower yieldsmore » from the boron treatment were the lowest out of seven treatments in three out of four fields. Also, sunflower yield from the boron treatment was significantly lower than both iron and sulfur treatments when all fields were combined.« less

DESCRIPTIVE ANALYSIS OF DIVALENT SALTS

PubMed Central

YANG, HEIDI HAI-LING; LAWLESS, HARRY T.

2005-01-01

Many divalent salts (e.g., calcium, iron, zinc), have important nutritional value and are used to fortify food or as dietary supplements. Sensory characterization of some divalent salts in aqueous solutions by untrained judges has been reported in the psychophysical literature, but formal sensory evaluation by trained panels is lacking. To provide this information, a trained descriptive panel evaluated the sensory characteristics of 10 divalent salts including ferrous sulfate, chloride and gluconate; calcium chloride, lactate and glycerophosphate; zinc sulfate and chloride; and magnesium sulfate and chloride. Among the compounds tested, iron compounds were highest in metallic taste; zinc compounds had higher astringency and a glutamate-like sensation; and bitterness was pronounced for magnesium and calcium salts. Bitterness was affected by the anion in ferrous and calcium salts. Results from the trained panelists were largely consistent with the psychophysical literature using untrained judges, but provided a more comprehensive set of oral sensory attributes. PMID:16614749

Iron, zinc, and copper in retinal physiology and disease.

PubMed

Ugarte, Marta; Osborne, Neville N; Brown, Laurence A; Bishop, Paul N

2013-01-01

The essential trace metals iron, zinc, and copper play important roles both in retinal physiology and disease. They are involved in various retinal functions such as phototransduction, the visual cycle, and the process of neurotransmission, being tightly bound to proteins and other molecules to regulate their structure and/or function or as unbound free metal ions. Elevated levels of "free" or loosely bound metal ions can exert toxic effects, and in order to maintain homeostatic levels to protect retinal cells from their toxicity, appropriate mechanisms exist such as metal transporters, chaperones, and the presence of certain storage molecules that tightly bind metals to form nontoxic products. The pathways to maintain homeostatic levels of metals are closely interlinked, with various metabolic pathways directly and/or indirectly affecting their concentrations, compartmentalization, and oxidation/reduction states. Retinal deficiency or excess of these metals can result from systemic depletion and/or overload or from mutations in genes involved in maintaining retinal metal homeostasis, and this is associated with retinal dysfunction and pathology. Iron accumulation in the retina, a characteristic of aging, may be involved in the pathogenesis of retinal diseases such as age-related macular degeneration (AMD). Zinc deficiency is associated with poor dark adaptation. Zinc levels in the human retina and RPE decrease with age in AMD. Copper deficiency is associated with optic neuropathy, but retinal function is maintained. The changes in iron and zinc homeostasis in AMD have led to the speculation that iron chelation and/or zinc supplements may help in its treatment. Copyright © 2013 Elsevier Inc. All rights reserved.

The co-occurrence of zinc deficiency and social isolation has the opposite effects on mood compared with either condition alone due to changes in the central norepinephrine system.

PubMed

Mitsuya, Hironori; Omata, Naoto; Kiyono, Yasushi; Mizuno, Tomoyuki; Murata, Tetsuhito; Mita, Kayo; Okazawa, Hidehiko; Wada, Yuji

2015-05-01

Nutritional and social environmental problems during the early stages of life are closely associated with the pathophysiology of mood disorders such as depression. Disruption or dysfunction of the central norepinephrine (NE) system is also considered to play a role in mood disorders. Therefore, we evaluated the effects of zinc deficiency and/or social isolation on mood and changes in the central NE system using rats. Compared with the controls, the rats subjected to zinc deficiency or social isolation alone exhibited increased anxiety-related behavior in the elevated plus maze and greater depression-like behavior in the forced swim test. However, the co-occurrence of zinc deficiency and social isolation resulted in decreased anxiety-related behavior and control levels of depression-like behavior. Social isolation alone decreased the rats' cerebral NE concentrations. The expression of the NE transporter was not affected by social isolation alone, but its expression in the locus coeruleus was markedly decreased by the co-occurrence of social isolation and zinc deficiency, and this change was accompanied by an increase in the blood concentration of 3-methoxy-4-hydroxyphenylglycol, which is a marker of central NE system activity. These findings suggest that zinc deficiency or social isolation alone induce anxious or depressive symptoms, but the presence of both conditions has anxiolytic or antidepressive effects. Furthermore, these opposing effects of mood-related behaviors were found to be associated with changes in the central NE system. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Yogurt protects against growth retardation in weanling rats fed diets high in phytic acid

PubMed Central

Gaetke, Lisa M.; McClain, Craig J.; Toleman, C. Jean; Stuart, Mary A.

2010-01-01

The purpose of this study was to determine the affects of adding yogurt to animal diets which were high in phytic acid (PA) and adequate in zinc (38 μg Zn/g). The PA:Zn molar ratio was 60:1. Zinc status was determined by documenting growth and measuring the zinc concentration in bone (tibia) and plasma. For 25 days, 6 groups (n=6) of Sprague-Dawley weanling rats were fed one of the following AIN-76 diets. Half of the diets contained PA. Four of the diets contained yogurt with either active or heat-treated (inactive) cultures added at 25% of the diet. Diets: (without PA) 1) AIN, 2) AIN with active yogurt, 3) AIN and inactive yogurt; and (with PA) 4) AIN with PA, 5) AIN with PA plus active yogurt, and 6) AIN with PA plus inactive yogurt. Body weight, weight gain, and zinc concentration in bone and plasma were measured, and feed efficiency ratio (FER) was calculated. Rats fed diets with PA and yogurt had normal growth compared to the control group. Growth retardation was evident in the group fed the diet with PA and no yogurt. This group had significantly lower body weight compared to all other groups (p<0.05). Rats fed diets with PA, with or without yogurt, had significantly lower zinc concentration in bone and plasma (p<0.05). Adding yogurt to diets high in PA resulted in normal growth in weanling rats, however, zinc concentration in bone and plasma was still sub-optimal. PMID:19269152

Mild zinc deficiency in male and female rats: early postnatal alterations in renal nitric oxide system and morphology.

PubMed

Tomat, Analia Lorena; Veiras, Luciana Cecilia; Aguirre, Sofía; Fasoli, Héctor; Elesgaray, Rosana; Caniffi, Carolina; Costa, María Ángeles; Arranz, Cristina Teresa

2013-03-01

Fetal and postnatal zinc deficiencies induce an increase in arterial blood pressure and impair renal function in male adult rats. We therefore hypothesized that these renal alterations are present in early stages of life and that there are sexual differences in the adaptations to this nutritional injury. The aim was to study the effects of moderate zinc deficiency during fetal life and lactation on renal morphology, oxidative stress, apoptosis, and the nitric oxide system in male and female rats at 21 d of life. Female Wistar rats received low (8 ppm) or control (30 ppm) zinc diets from the beginning of pregnancy to weaning. Glomerulus number, morphology, oxidative stress, apoptotic cells, nitric oxide synthase activity, and protein expression were evaluated in the kidneys of offspring at 21 d. Zinc deficiency decreased the nephron number, induced glomerular hypertrophy, increased oxidative damage, and decreased nitric oxide synthase activity in the male and female rat kidneys. Nitric oxide synthase activity was not affected by inhibitors of the neuronal or inducible isoforms, so nitric oxide was mainly generated by the endothelial isoenzyme. Gender differences were observed in glomerular areas and antioxidant enzyme activities. Zinc deficiency during fetal life and lactation induces an early decrease in renal functional units, associated with a decrease in nitric oxide activity and an increase in oxidative stress, which would contribute to increased arterial blood pressure and renal dysfunction in adulthood. The sexual differences observed in this model may explain the dissimilar development of hypertension and renal diseases in adult life. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of supplementary zinc on orthodontic tooth movement in a rat model

PubMed Central

Sadegh, Ahmad Akhoundi Mohammad; Rezvaneh, Ghazanfari; Shahroo, Etemad-Moghadam; Mojgan, Alaeddini; Azam, Khorshidian; Shahram, Rabbani; Reza, Shamshiri Ahmad; Nafiseh, Momeni

2016-01-01

ABSTRACT Introduction: Osteoclasts and osteoblasts are responsible for regulating bone homeostasis during which the trace element zinc has been shown to exert a cumulative effect on bone mass by stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption. Objective: The aim of the present study was to investigate the effects of zinc (Zn) on orthodontic tooth movement (OTM) in a rat model. Material and Methods: A total of 44 male Wistar rats were divided into four groups of 11 animals each and received 0, 1.5, 20 and 50 ppm Zn in distilled water for 60 days. In the last 21 days of the study, nickel-titanium closed coil springs were ligated between maxillary right incisors and first molars of all rats, and tooth movement was measured at the end of this period. Histological analysis of hematoxylin/eosin slides was performed to assess root resorption lacunae, osteoclast number and periodontal ligament (PDL) width. Results: Mean OTM was calculated as 51.8, 49.1, 35.5 and 45 µm in the 0, 1.5, 20 and 50 ppm zinc-receiving groups, respectively. There were no significant differences in neither OTM nor histological parameters among the study groups (p > 0.05). Conclusion: According to the results obtained in the current investigation, increase in supplementary zinc up to 50 ppm does not affect the rate of OTM neither bone and root resorption in rats. PMID:27275614

Supersaturation of aqueous species and hydrothermal crystal growth of ZnO

NASA Astrophysics Data System (ADS)

Gelabert, M. C.

2015-05-01

Synthesis of ZnO crystals prepared with zinc acetate or chloride, disodium dihydrogen ethylenediaminetetraacetate (EDTA), potassium hydroxide and sodium triflate at 200 °C and variable pH 8-12 is reported. Crystals were imaged and size-analyzed with optical microscopy. Using aqueous speciation modeling software, supersaturation dependence on pH was calculated for five zinc species-Zn2+, Zn(OH)+, Zn(OH)2, Zn(OH)3- and Zn(OH)42- -to investigate connections between predominate crystal habits at different pH and dominant aqueous species. For zinc acetate and chloride systems, the zinc species with highest supersaturation was Zn(OH)42- throughout the pH 8-12 range, and the second highest was Zn2+ or Zn(OH)3-, with a crossover pH of 10.2-10.4 depending on counterion. The prominence of the tetrahydroxyl zinc species in ZnO crystal growth is supported by these calculations, and total supersaturation is inversely proportional to average crystal sizes, as expected. Optical microscopy and size analysis on products revealed crystals with a needle or prismatic habit throughout the studied pH range, and the change in aspect ratio correlates with supersaturation changes for the Zn2+ in this pH range, thus suggesting that growth rates along the [001] crystallographic direction are affected by small concentration changes of this ion.

Immune malfunction in the GPR39 zinc receptor of knockout mice: Its relationship to depressive disorder.

PubMed

Młyniec, Katarzyna; Trojan, Ewa; Ślusarczyk, Joanna; Głombik, Katarzyna; Basta-Kaim, Agnieszka; Budziszewska, Bogusława; Skrzeszewski, Jakub; Siwek, Agata; Holst, Birgitte; Nowak, Gabriel

2016-02-15

Depression is a serious psychiatric disorder affecting not only the monaminergic, glutamatergic, and GABAergic neurosystems, but also the immune system. Patients suffering from depression show disturbance in the immune parameters as well as increased susceptibility to infections. Zinc is well known as an anti-inflammatory agent, and its link with depression has been proved, zinc deficiency causing depression- and anxiety-like behavior with immune malfunction. It has been discovered that trace-element zinc acts as a neurotransmitter in the central nervous system via zinc receptor GPR39. In this study we investigated whether GPR39 knockout would cause depressive-like behavior as measured by the forced swim test, and whether these changes would coexist with immune malfunction. In GPR39 knockout mice versus a wild-type control we found: i) depressive-like behavior; ii) significantly reduced thymus weight; (iii) reduced cell viability of splenocytes; iv) reduced proliferative response of splenocytes; and v) increased IL-6 production of splenocytes after ConA stimulation and decreased IL-1b and IL-6 release after LPS stimulation. The results indicate depressive-like behavior in GPR39 KO animals with an immune response similar to that observed in depressive disorder. Here for the first time we show immunological changes under GPR39-deficient conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Reducing anti-nutritional factor and enhancing yield with advancing time of planting and zinc application in grasspea in Ethiopia.

PubMed

Sarker, Ashutosh; Fikre, Asnake; El-Moneim, Ali M Abd; Nakkoul, Hani; Singh, Murari

2018-01-01

Grasspea (Lathyrus sativus L.) is an important pulse crop for food, feed and sustainable crop production systems in Ethiopia. Despite its advantages in nutrition and adaptability to harsh climate and low fertile soil, it contains a neurotoxin, β-N-oxalyl-α,β-diamiono propionic acid (β-ODAP), which paralyses the lower limbs and is affected by genotypic and agronomic factors. To determine the effect of zinc application and planting date on yield and β-ODAP content of two genotypes, experiments were conducted in two regions of Ethiopia. The main effects of variety, sowing date and zinc and their interactions were significant (P < 0.001) for β-ODAP and seed yield, which had a linear relationship with zinc. For the improved grasspea variety, an application of 20 kg ha -1 zinc showed a reduction of β-ODAP from 0.15% to 0.088% at Debre Zeit and 0.14% to 0.08% at Sheno and increased its yield from 841 kg ha -1 to 2260 kg ha -1 at Debre Zeit and from 715 to 1835 kg ha -1 at Sheno. Early sowing showed a reduction in ODAP content in relation to the late sowing. An application of Zn beyond even 20 kg ha -1 with an early sowing is recommended for the improved variety. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Eluted zinc ions stimulate osteoblast differentiation and mineralization in human dental pulp stem cells for bone tissue engineering.

PubMed

Yusa, Kazuyuki; Yamamoto, Osamu; Iino, Mitsuyoshi; Takano, Hiroshi; Fukuda, Masayuki; Qiao, Zhiwei; Sugiyama, Toshihiro

2016-11-01

Zinc is an essential element for proliferation, differentiation and survival in various cell types. In a previous study, we found that zinc ions released from zinc-modified titanium surfaces (eluted zinc ions; EZ) stimulate cell viability, osteoblast marker gene expression and calcium deposition in human bone marrow-derived mesenchymal cells (hBMCs). The aim of the present study was to investigate the effects of EZ on osteoblast differentiation among dental pulp stem cells (DPSCs) in vitro. In this study, we evaluated the effects of EZ on osteogenesis in DPSCs. Osteoblast and osteoclast marker gene expression was evaluated by real-time PCR. We also evaluated alkaline phosphatase (ALP) staining and calcium deposition. We found that EZ stimulated osteoblast marker gene (type I collagen, alkaline phosphatase (ALP), osteocalcin (OCN) and Runx2) expression, vascular endothelial growth factor A (VEGF-A), and TGF-beta signaling pathway-related gene expression after 7days of incubation. Osteoclastogenesis occurs in a receptor for activated nuclear-factor kappa B ligand (RANKL)/osteoprotegerin (OPG)-independent manner. Real-time PCR analysis revealed that EZ did not affect RANKL or OPG mRNA expression. It was also revealed that EZ induced alkaline phosphatase (ALP) staining and calcium deposition in DPSCs. Collectively, these results demonstrate the potential for clinical application to prospective treatment of bone diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nutritional supplements for people being treated for active tuberculosis.

PubMed

Abba, Katharine; Sudarsanam, Thambu D; Grobler, Liesl; Volmink, Jimmy

2008-10-08

Tuberculosis is a serious infection affecting mainly the lungs. It may contribute to nutritional deficiencies which in turn may delay recovery by depressing immune functions. Nutritional supplements might therefore promote recovery in people being treated for tuberculosis. To assess the provision of oral nutritional supplements to promote the recovery of people being treated with antituberculous drug therapy for active tuberculosis. We searched the Cochrane Infectious Disease Group Specialized Register (June 2008), CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE (June 2008), EMBASE (June 2008), LILACS (June 2008), mRCT (June 2008), the Indian Journal of Tuberculosis (1983 to June 2008), and checked the reference lists of all included studies. Randomized controlled trials comparing any oral nutritional supplement given for at least four weeks with no nutritional intervention, placebo, or dietary advice only for people being treated for active tuberculosis. Two authors independently selected trials, extracted data, and assessed risk of bias. We calculated risk ratios (RR) for dichotomous variables and mean differences (MD) for continuous variables, with 95% confidence intervals (CI). We pooled data from trials with similar interventions and outcomes. Twelve trials (3393 participants) were included. Five trials had adequate allocation concealment. Interventions included a high energy supplement, high cholesterol diet, vitamin D, vitamin A, zinc, arginine, multiple micronutrient supplements, combined multiple micronutrient supplements and zinc, combined vitamin A and zinc, and combined vitamin A and selenium. The following supplements were associated with increased body weight at follow up: high energy supplements (MD 1.73 kg, 95% CI 0.81 to 2.65; 34 participants, 1 trial); multiple micronutrients plus additional zinc (MD 2.37 kg, 95% CI 2.21 to 2.53; 192 participants, 1 trial); and vitamin A plus zinc (MD 3.10 kg, 95% CI 0.74 to 5.46; 80 participants, 1 trial). There was no evidence that any supplement affected the number of deaths or number of participants with sputum test positive results at the end of treatment. There is limited evidence that high energy supplements and some combinations of zinc with other micronutrients may help people with tuberculosis to gain weight. There is not enough evidence to assess the effect of other combinations of nutrients. A number of relevant trials are in progress, and, where appropriate, the results will be incorporated into future updates of this review.

Dietary calcium intake, serum copper concentration and bone density in postmenopausal women

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strause, L.; Andon, M.B.; Howard, G.

1991-03-11

Data from experimental animal nutrition and animal husbandry indicate that several trace minerals, including copper (Cu) are involved in bone metabolism. In addition, a large body of data suggests that low dietary calcium (Ca) intake is a risk factor for age related bone loss. The authors measured the serum (Cu), dietary Ca intake (dCa) and bone mineral density (BMD) in the spine of 225 postmenopausal women. The median dCa and serum (Cu) were 562 mg/d and 9.73 umoles/L, respectively. Serum (Cu) but, not dCa, was greater in subjects with a history of estrogen therapy (ERT). BMD was higher in subjectsmore » with above median dCa and serum (Cu) (group 1) compared to those with below median values (group 2). BMD was intermediate for subjects with either Low serum (Cu):High dCa or High serum (Cu):Low dCa. This relationship was observed in the subject group as a whole, as well as in subgroups partitioned according to history of ERT. Groups 1 and 2 did not differ in basic demographic characteristics such as age, age at menopause, body weight and height. These data support the hypothesis that Ca and Cu nutriture are determinants of skeletal health in postmenopausal women.« less

Folic acid: influence on the outcome of pregnancy.

PubMed

Scholl, T O; Johnson, W G

2000-05-01

The periconceptional use of folic acid-containing supplements reduces the first occurrence, as well as the recurrence, of neural tube defects. Women of populations in which adverse pregnancy outcomes are prevalent often consume diets that contain a low density of vitamins and minerals, including folate. Folate intake may need to be sustained after complete closure of the neural tube to decrease the risk of other poor pregnancy outcomes. A central feature of embryonic and fetal development is widespread cell division; folate is central because of its role in nucleic acid synthesis. During gestation, marginal folate nutriture can impair cellular growth and replication in the fetus or placenta. Folate deficiency can occur because dietary folate intake is low or because the metabolic requirement for folate is increased by a particular genetic defect or defects. During pregnancy, low concentrations of dietary and circulating folate are associated with increased risks of preterm delivery, infant low birth weight, and fetal growth retardation. A metabolic effect of folate deficiency is an elevation of blood homocysteine. Likewise, the presence of maternal homocysteine concentrations have been associated both with increased habitual spontaneous abortion and pregnancy complications (eg, placental abruption and preeclampsia), which increase the risk of poor pregnancy outcome and of decreased birth weight and gestation duration.

Metals in wine--impact on wine quality and health outcomes.

PubMed

Tariba, Blanka

2011-12-01

Metals in wine can originate from both natural and anthropogenic sources, and its concentration can be a significant parameter affecting consumption and conservation of wine. Since metallic ions have important role in oxide-reductive reactions resulting in wine browning, turbidity, cloudiness, and astringency, wine quality depends greatly on its metal composition. Moreover, metals in wine may affect human health. Consumption of wine may contribute to the daily dietary intake of essential metals (i.e., copper, iron, and zinc) but can also have potentially toxic effects if metal concentrations are not kept under allowable limits. Therefore, a strict analytical control of metal concentration is required during the whole process of wine production. This article presents a critical review of the existing literature regarding the measured metal concentration in wine, methods applied for their determination, and possible sources, as well as their impact on wine quality and human health. The main focus is set on aluminum, arsenic, cadmium, chromium, copper, iron, manganese, nickel, lead, and zinc, as these elements most often affect wine quality and human health.

Hyperforin changes the zinc-storage capacities of brain cells.

PubMed

Gibon, Julien; Richaud, Pierre; Bouron, Alexandre

2011-12-01

In vitro and in vivo experiments were carried out to investigate the consequences on brain cells of a chronic treatment with hyperforin, a plant extract known to dissipate the mitochondrial membrane potential and to release Zn(2+) and Ca(2+) from these organelles. Dissociated cortical neurons were grown in a culture medium supplemented with 1 μM hyperforin. Live-cell imaging experiments with the fluorescent probes FluoZin-3 and Fluo-4 show that a 3 day-hyperforin treatment diminishes the size of the hyperforin-sensitive pools of Ca(2+) and Zn(2+) whereas it increases the size of the DTDP-sensitive pool of Zn(2+) without affecting the ionomycin-sensitive pool of Ca(2+). When assayed by quantitative PCR the levels of mRNA coding for metallothioneins (MTs) I, II and III were increased in cortical neurons after a 3 day-hyperforin treatment. This was prevented by the zinc chelator TPEN, indicating that the plant extract controls the expression of MTs in a zinc-dependent manner. Brains of adult mice who received a daily injection (i.p.) of hyperforin (4 mg/kg/day) for 4 weeks had a higher sulphur content than control animals. They also exhibited an enhanced expression of the genes coding for MTs. However, the long-term treatment did not affect the brain levels of calcium and zinc. Based on these results showing that hyperforin influences the size of the internal pools of Zn(2+), the expression of MTs and the brain cellular sulphur content, it is proposed that hyperforin changes the Zn-storage capacity of brain cells and interferes with their thiol status. Copyright © 2011 Elsevier Ltd. All rights reserved.

Toxicity of Functional Nano-Micro Zinc Oxide Tetrapods: Impact of Cell Culture Conditions, Cellular Age and Material Properties

PubMed Central

Papavlassopoulos, Heike; Mishra, Yogendra K.; Kaps, Sören; Paulowicz, Ingo; Abdelaziz, Ramzy; Elbahri, Mady; Maser, Edmund; Adelung, Rainer; Röhl, Claudia

2014-01-01

With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development. PMID:24454775

Chemical bath deposited ZnS buffer layer for Cu(In,Ga)Se2 thin film solar cell

NASA Astrophysics Data System (ADS)

Hong, Jiyeon; Lim, Donghwan; Eo, Young-Joo; Choi, Changhwan

2018-02-01

The dependence of Zn precursors using zinc sulfate (ZnSO4), zinc acetate (Zn(CH3COO)2), and zinc chloride (ZnCl2) on the characteristics of the chemical bath deposited ZnS thin film used as a buffer layer of Cu(In,Ga)Se2 (CIGS) thin film solar cell was studied. It is found that the ZnS film deposition rate increases with higher stability constant during decomplexation reaction of zinc ligands, which affects the crack formation and the amount of sulfur and oxygen contents within the film. The band gap energies of all deposited films are in the range of 3.40-3.49 eV, which is lower than that of the bulk ZnS film due to oxygen contents within the films. Among the CIGS solar cells having ZnS buffer layers prepared by different Zn precursors, the best cell efficiency with 9.4% was attained using Zn(CH3COO)2 precursor due to increased Voc mainly. This result suggests that [Zn(NH3)4]2+ complex formation should be well controlled to attain the high quality ZnS thin films.

Immobilization of mercury and zinc in an alkali-activated slag matrix.

PubMed

Qian, Guangren; Sun, Darren Delai; Tay, Joo Hwa

2003-07-04

The behavior of heavy metals mercury and zinc immobilized in an alkali-activated slag (AAS) matrix has been evaluated using physical property tests, pore structure analysis and XRD, TG-DTG, FTIR and TCLP analysis. Low concentrations (0.5%) of mercury and zinc ions had only a slight affect on compressive strength, pore structure and hydration of AAS matrixes. The addition of 2% Hg ions to the AAS matrix resulted in a reduction in early compressive strength but no negative effects were noticed after 28 days of hydration. Meanwhile, 2% Hg ions can be effectively immobilized in the AAS matrix with the leachate meeting the USEPA TCLP mercury limit. For a 2% Zn-doped AAS matrix, the hydration of the AAS paste was greatly retarded and the zinc concentration in the leachate from this matrix was higher than 5mg/l even at 28 days. Based on these results, we conclude that the physical encapsulation and chemical fixation mechanisms were likely to be responsible for the immobilization of Hg ions in the AAS matrix while only chemical fixation mechanisms were responsible for the immobilization of Zn ions in the AAS matrix.

OsSUV3 functions in cadmium and zinc stress tolerance in rice (Oryza sativa L. cv IR64).

PubMed

Sahoo, Ranjan Kumar; Tuteja, Narendra

2014-01-01

Protein of nuclear encoded SUV3 (suppressor of Var 3) gene is a DNA and RNA helicase, localized in mitochondria and is a subunit of the degradosome complex involved in regulation of RNA surveillance and turnover. To overcome the abiotic stress-induced loss of crop yield, a multi-stress tolerant trait is required. Beside salinity stress the heavy metals including cadmium and zinc also affect the yield and quality of food crops. Since rice is a one of the staple food therefore it is important to develop a multi-stress including salinity and metal tolerant variety. Recently we have reported the role of OsSUV3 in salinity stress tolerance in rice; however, its role in metal stress has not been studied so far. Here we report that in response to cadmium and zinc stress the OsSUV3 transcript level is induced in rice and its overexpression in transgenic IR64 rice plants confers the metal stress tolerance. In addition to its previously reported role in salinity stress tolerance, this study further shows the role of OsSUV3 helicase in cadmium and zinc stress tolerance suggesting its involvement in multi-stress tolerance.

Does Zinc Sulfate Prevent Therapy-Induced Taste Alterations in Head and Neck Cancer Patients? Results of Phase III Double-Blind, Placebo-Controlled Trial from the North Central Cancer Treatment Group (N01C4)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halyard, Michele Y.; Jatoi, Aminah; Sloan, Jeff A.

2007-04-01

Purpose: Taste alterations (dysgeusia) are well described in head and neck cancer patients who undergo radiotherapy (RT). Anecdotal observations and pilot studies have suggested zinc may mitigate these symptoms. This multi-institutional, double-blind, placebo-controlled trial was conducted to provide definitive evidence of this mineral's palliative efficacy. Methods and Materials: A total of 169 evaluable patients were randomly assigned to zinc sulfate 45 mg orally three times daily vs. placebo. Treatment was to be given throughout RT and for 1 month after. All patients were scheduled to receive {>=}2,000 cGy of external beam RT to {>=}30% of the oral cavity, were ablemore » to take oral medication, and had no oral thrush at study entry. Changes in taste were assessed using the previously validated Wickham questionnaire. Results: At baseline, the groups were comparable in age, gender, and planned radiation dose (<6,000 vs. {>=}6,000 cGy). Overall, 61 zinc-treated (73%) and 71 placebo-exposed (84%) patients described taste alterations during the first 2 months (p = 0.16). The median interval to taste alterations was 2.3 vs. 1.6 weeks in the zinc-treated and placebo-exposed patients, respectively (p = 0.09). The reported taste alterations included the absence of any taste (16%), bitter taste (8%), salty taste (5%), sour taste (4%), sweet taste (5%), and the presence of a metallic taste (10%), as well as other descriptions provided by a write in response (81%). Zinc sulfate did not favorably affect the interval to taste recovery. Conclusion: Zinc sulfate, as prescribed in this trial, did not prevent taste alterations in cancer patients who were undergoing RT to the oral pharynx.« less

The effect of zinc and vitamin E cosupplementation on metabolic status and its related gene expression in patients with gestational diabetes.

PubMed

Ostadmohammadi, Vahidreza; Samimi, Mansooreh; Mobini, Moein; Zarezade Mehrizi, Maryam; Aghadavod, Esmat; Chamani, Maryam; Dastorani, Majid; Asemi, Zatollah

2018-06-12

The aim of this study was to determine the effects of zinc and vitamin E cosupplementation on metabolic status and gene expression related to insulin and lipid metabolism in women with gestational diabetes mellitus (GDM). Fifty-four women, in the age range of 18-40 years, diagnosed with GDM were recruited for this randomized, double-blinded, placebo-controlled trial. Subjects were randomly allocated into two intervention groups to either taking 233 mg/day Zinc Gluconate plus 400-IU/day vitamin E supplements or placebo (n = 27 each group) for 6 weeks. Gene expression related to insulin and lipid metabolism was evaluated in peripheral blood mononuclear cells (PBMCs) of women with GDM using RT-PCR method. Participants who received zinc plus vitamin E supplements had significantly lower serum insulin levels (β = -3.81; 95% CI, -5.90, -1.72; p = .001), homeostasis model of assessment-insulin resistance (β = -0.96; 95% CI, -1.54, -0.38; p = .002), serum total-cholesterol (β = -8.56; 95% CI, -16.69, -0.43; p = .03) and low density lipoprotein-cholesterol (LDL)-cholesterol (β = -8.72; 95% CI, -15.27, -2.16; p = .01), and higher quantitative insulin sensitivity check index (β = 0.01; 95% CI, 0.005, 0.02; p = .007) compared with the placebo. Moreover, zinc and vitamin E cosupplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ; p = .03) and low-density lipoprotein receptor (LDLR; p = .04) compared with the placebo. Though, zinc and vitamin E combination did not affect other metabolic parameters. Overall, zinc and vitamin E cosupplementation for 6 weeks in women with GDM significantly improved insulin metabolism, lipid profile, and the gene expression levels of PPAR-γ and LDLR.

Inorganic zinc supplementation modulates heat shock and immune response in heat stressed peripheral blood mononuclear cells of periparturient dairy cows.

PubMed

Sheikh, Aasif Ahmad; Aggarwal, Anjali; B, Indu; Aarif, Ovais

2017-06-01

Thermal stress in India is one of the major constraints affecting dairy cattle productivity. Every attempt should be made to ameliorate the heat and calving related stress in high producing dairy cows for higher economic returns. In the current study, inorganic zinc was tried to alleviate the adverse effects of thermal stress in periparturient cows. Twelve cows, six each of Sahiwal and Karan Fries (KF) in their second parity with confirmed pregnancy were chosen for the experiment. The blood samples were collected periparturiently on three occasions viz. -21, 0 and +21 days relative to calving. The in vitro study was conducted after isolating peripheral blood mononuclear cells (PBMC) from whole blood. The cultured PBMC were subjected to three different levels of exposures viz. 37°C as control, 42°C to induce thermal stress and 42°C + zinc to ameliorate the adverse effects of high temperature. Heat shock lead to a significant (P<0.05) rise in the level of heat shock proteins (HSP). HSP was more on the day of calving as well. KF showed more HSP concentration than Sahiwal breed indicating the heat bearing capacity of later. Zinc treatment to thermally stressed PBMC caused a fall in the HSP concentration in both the breeds during periparturient period. Moreover, heat stress increased significantly (P<0.05) the Interleukin 6 (IL-6) concentration which declined upon zinc supplementation to PBMC. IL-6 levels decreased periparturiently. Heat and calving related stress caused a fall in the IL-12 levels which increased significantly (P<0.05) with zinc supplementation. These findings suggest that zinc supplementation attenuates the HSP response and augments immunity in PBMC of periparturient dairy cows. The study could help to alleviate the heat stress and potentiate immunity by providing mineral supplements in periparturient dairy cattle habituating tropics. Copyright © 2017 Elsevier Inc. All rights reserved.

An analytical model for inductively coupled implantable biomedical devices with ferrite rods.

PubMed

Theilmann, P T; Asbeck, P M

2009-02-01

Using approximations applicable to near field coupled implants simplified expressions for the complex mutual inductance of coaxial aligned coils with and without a cylindrical ferrite rod are derived. Experimental results for ferrite rods of various sizes and permeabilities are presented to verify the accuracy of this expression. An equivalent circuit model for the inductive link between an implant and power coil is then presented and used to investigate how ferrite size, permeability and loss affect the power available to the implant device. Enhancements in coupling provided by high frequency, low permeability nickel zinc rods are compared with low frequency high permeability manganese zinc rods.

Assessment of metals pollution on agricultural soil surrounding a lead-zinc mining area in the Karst region of Guangxi, China.

PubMed

Zhang, Chaolan; Li, Zhongyi; Yang, Weiwei; Pan, Liping; Gu, Minghua; Lee, DoKyoung

2013-06-01

Soil samples were collected on farmland in a lead-zinc mining area in the Karst region of Guangxi, China. The contamination of the soil by eight metals (Cd, Hg, As, Cu, Pb, Cr, Zn, Ni) was determined. Among all these metals, Cd is the most serious pollutant in this area. Zn, Hg as well asPb can also be measured at high levels, which may affect the crop production. All other metals contributed marginally to the overall soil contamination. Besides the evaluation of single metals, the Nemerow synthetic index indicated that the soil is not suitable for agricultural use.

Lack of effect of mossy fiber-released zinc on granule cell GABA(A) receptors in the pilocarpine model of epilepsy.

PubMed

Molnár, P; Nadler, J V

2001-05-01

The recurrent mossy fiber pathway of the dentate gyrus expands dramatically in the epileptic brain and serves as a mechanism for synchronization of granule cell epileptiform activity. It has been suggested that this pathway also promotes epileptiform activity by inhibiting GABA(A) receptor function through release of zinc. Hippocampal slices from pilocarpine-treated rats were used to evaluate this hypothesis. The rats had developed status epilepticus after pilocarpine administration, followed by robust recurrent mossy fiber growth. The ability of exogenously applied zinc to depress GABA(A) receptor function in dentate granule cells depended on removal of polyvalent anions from the superfusion medium. Under these conditions, 200 microM zinc reduced the amplitude of the current evoked by applying muscimol to the proximal portion of the granule cell dendrite (23%). It also reduced the mean amplitude (31%) and frequency (36%) of miniature inhibitory postsynaptic currents. Nevertheless, repetitive mossy fiber stimulation (10 Hz for 1 s, 100 Hz for 1 s, or 10 Hz for 5 min) at maximal intensity did not affect GABA(A) receptor-mediated currents evoked by photorelease of GABA onto the proximal portion of the dendrite, where recurrent mossy fiber synapses were located. These results could not be explained by stimulation-induced depletion of zinc from the recurrent mossy fiber boutons. Negative results were obtained even during exposure to conditions that promoted transmitter release and synchronized granule cell activity (6 mM [K(+)](o), nominally Mg(2+)-free medium, 33 degrees C). These results suggest that zinc released from the recurrent mossy fiber pathway did not reach a concentration at postsynaptic GABA(A) receptors sufficient to inhibit agonist-evoked activation.

Concentrations and bioaccessibility of metals in vegetation and dust near a mining haul road, Cape Krusenstern National Monument, Alaska

USGS Publications Warehouse

Brumbaugh, William G.; Morman, Suzette A.; May, Thomas W.

2011-01-01

Vegetation, sub-surface peat, and road dust were sampled near the Delong Mountain Transportation System (DMTS) haul road in northwest Alaska in 2005-2006 to document aluminum, barium, cadmium, lead, and zinc concentrations, and to evaluate bioaccessibility of these metals. The DMTS haul road is the transport corridor between Red Dog Mine (a large-scale, lead-zinc mine and mill) and the coastal shipping port, and it traverses National Park Service lands. Compared to reference locations, total metal concentrations in four types of vegetation (birch, cranberry, and willow leaves, and cotton grass blades/stalks) collected 25 m from the haul road were enriched on average by factors of 3.5 for zinc, 8.0 for barium, 20 for cadmium, and 150 for lead. Triple rinsing of vegetation with a water/methanol mixture reduced metals concentrations by at most 50%, and cadmium and zinc concentrations were least affected by rinsing. Cadmium and zinc bioaccessibility was greater in vegetation (50% to 100%) than in dust (15% to 20%); whereas the opposite pattern was observed for lead bioaccessibility (<30% in vegetation; 50% in dust). Barium exhibited low-to-intermediate bioaccessibility in dust and vegetation (20% to 40%), whereas aluminum bioaccessibility was relatively low (<6%) in all sample types. Our reconnaissance-level study indicates that clean-up and improvements in lead/zinc concentrate transfer activities have been effective; however, as of 2006, metal dispersion from past and/or present releases of fugitive dusts along the DMTS road still may have been contributing to elevated metals in surface vegetation. Vegetation was most enriched in lead, but because bioaccessibility of cadmium was greater, any potential risks to animals that forage near the haul road might be equally important for both of these metals.

The Effect of Adjuvant Zinc Therapy on Recovery from Pneumonia in Hospitalized Children: A Double-Blind Randomized Controlled Trial

PubMed Central

Qasemzadeh, Mohammad Javad; Fathi, Mahdi; Tashvighi, Maryam; Gharehbeglou, Mohammad; Yadollah-Damavandi, Soheila; Parsa, Yekta; Rahimi, Ebrahim

2014-01-01

Objectives. Pneumonia is one of the common mortality causes in young children. Some studies have shown beneficial effect of zinc supplements on treatment of pneumonia. The present study aimed to investigate the effects of short courses of zinc administration on recovery from this disease in hospitalized children. Methods. In a parallel Double-Blind Randomized Controlled Trial at Ayatollah Golpaygani Hospital in Qom, 120 children aged 3–60 months with pneumonia were randomly assigned 1 : 1 to receive zinc or placebo (5 mL every 12 hours) along with the common antibiotic treatments until discharge. Primary outcome was recovery from pneumonia which included the incidence and resolving clinical symptoms and duration of hospitalization. Results. The difference between two groups in all clinical symptoms at admittance and the variables affecting the disease such as age and sex were not statistically significant (P < 0.05) at baseline. Compared to the placebo group, the treatment group showed a statistically significant decrease in duration of clinical symptoms (P = 0.044) and hospitalization (P = 0.004). Conclusions. Supplemental administration of zinc can expedite the healing process and results in faster resolution of clinical symptoms in children with pneumonia. In general, zinc administration, along with common antibiotic treatments, is recommended in this group of children. It can also reduce the drug resistance caused by multiple antibiotic therapies. This trial is approved by Medical Ethic Committee of Islamic Azad University in Iran (ID Number: 8579622-Q). This study is also registered in AEARCTR (The American Economic Association's Registry for Randomized Controlled Trials). This trial is registered with RCT ID: AEARCTR-0000187. PMID:24955282

Zinc deficiency in field-grown pecan trees: changes in leaf nutrient concentrations and structure.

PubMed

Ojeda-Barrios, Dámaris; Abadía, Javier; Lombardini, Leonardo; Abadía, Anunciación; Vázquez, Saúl

2012-06-01

Zinc (Zn) deficiency is a typical nutritional disorder in pecan trees [Carya illinoinensis (Wangenh.) C. Koch] grown under field conditions in calcareous soils in North America, including northern Mexico and south-western United States. The aim of this study was to assess the morphological and nutritional changes in pecan leaves affected by Zn deficiency as well as the Zn distribution within leaves. Zinc deficiency led to decreases in leaf chlorophyll concentrations, leaf area and trunk cross-sectional area. Zinc deficiency increased significantly the leaf concentrations of K and Ca, and decreased the leaf concentrations of Zn, Fe, Mn and Cu. All nutrient values found in Zn-deficient leaves were within the sufficiency ranges, with the only exception of Zn, which was approximately 44, 11 and 9 µg g(-1) dry weight in Zn-sufficient, moderately and markedly Zn-deficient leaves, respectively. Zinc deficiency led to decreases in leaf thickness, mainly due to a reduction in the thickness of the palisade parenchyma, as well as to increases in stomatal density and size. The localisation of Zn was determined using the fluorophore Zinpyr-1 and ratio-imaging technique. Zinc was mainly localised in the palisade mesophyll area in Zn-sufficient leaves, whereas no signal could be obtained in Zn-deficient leaves. The effects of Zn deficiency on the leaf characteristics of pecan trees include not only decreases in leaf chlorophyll and Zn concentrations, but also a reduction in the thickness of the palisade parenchyma, an increase in stomatal density and pore size and the practical disappearance of Zn leaf pools. These characteristics must be taken into account to design strategies to correct Zn deficiency in pecan tree in the field. Copyright © 2012 Society of Chemical Industry.

Effects of acidic recharge on groundwater at the St. Kevin Gulch site, Leadville, Colorado

USGS Publications Warehouse

Paschke, S.S.; Harrison, W.J.; Walton-Day, K.

2001-01-01

The acid rock drainage-affected stream of St. Kevin Gulch recharges the Quaternary sand and gravel aquifer of Tennessee Park, near Leadville, Colorado, lowering pH and contributing iron, cadmium, copper, zinc and sulphate to the ground-water system. Dissolved metal mobility is controlled by the seasonal spring runoff as well as oxidation/reduction (redox) reactions in the aquifer. Oxidizing conditions occur in the unconfined portions of the aquifer whilst sulphate-reducing conditions are found down gradient where semi-confined groundwater flow occurs beneath a natural wetland. Iron-reducing conditions occur in the transition from unconfined to semi-confined groundwater flow. Dissolved iron concentrations are low to not detectable in the alluvial fan recharge zone and increase in a down gradient direction. The effects of low-pH, metal-rich recharge are pronounced during low-flow in the fall when there is a defined area of low pH groundwater with elevated concentrations of dissolved zinc, cadmium, copper and sulphate adjacent to St. Kevin Gulch. Dissolved metal and sulphate concentrations in the recharge zone are diluted during spring runoff, although the maximum concentrations of dissolved zinc, cadmium, copper and sulphate occur at selected down gradient locations during high flow. Dissolved zinc, cadmium and copper concentrations are low to not detectable, whereas dissolved iron concentrations are greatest, in groundwater samples from the sulphate-reducing zone. Attenuation of zinc, cadmium and copper beneath the wetland suggests sulphide mineral precipitation is occurring in the semi-confined aquifer, in agreement with previous site investigations and saturation index calculations. Adsorption of dissolved zinc, cadmium and copper onto iron hydroxides is a minor attenuation process due to the low pH of the groundwater system.

Biomarkers of metals exposure in fish from lead-zinc mining areas of Southeastern Missouri, USA

USGS Publications Warehouse

Schmitt, C.J.; Whyte, J.J.; Roberts, A.P.; Annis, M.L.; May, T.W.; Tillitt, D.E.

2007-01-01

The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) from 16 sites representing a range of conditions relative to mining activities were collected. Samples were analyzed for metals (also reported in a companion paper) and for biomarkers of metals exposure [erythrocyte ??-aminolevulinic acid dehydratase (ALA-D) activity; concentrations of zinc protoporphyrin (ZPP), iron, and hemoglobin (Hb) in blood; and hepatic metallothionein (MT) gene expression and lipid peroxidation]. Blood lead concentrations were significantly higher and ALA-D activity significantly lower in all species at sites nearest to active lead-zinc mines and in a stream contaminated by historical mining than at reference or downstream sites. ALA-D activity was also negatively correlated with blood lead concentrations in all three species but not with other metals. Iron and Hb concentrations were positively correlated in all three species, but were not correlated with any other metals in blood or liver in any species. MT gene expression was positively correlated with liver zinc concentrations, but neither MT nor lipid peroxidase differences among fish grouped according to lead concentrations were statistically significant. ZPP was not detected by hematofluorometry in most fish, but fish with detectable ZPP were from sites affected by mining. Collectively, these results confirm that metals are released to streams from active lead-zinc mining sites and are accumulated by fish. ?? 2007 Elsevier Inc. All rights reserved.

Loss of synaptic zinc transport in progranulin deficient mice may contribute to progranulin-associated psychopathology and chronic pain.

PubMed

Hardt, Stefanie; Heidler, Juliana; Albuquerque, Boris; Valek, Lucie; Altmann, Christine; Wilken-Schmitz, Annett; Schäfer, Michael K E; Wittig, Ilka; Tegeder, Irmgard

2017-11-01

Affective and cognitive processing of nociception contributes to the development of chronic pain and vice versa, pain may precipitate psychopathologic symptoms. We hypothesized a higher risk for the latter with immanent neurologic diseases and studied this potential interrelationship in progranulin-deficient mice, which are a model for frontotemporal dementia, a disease dominated by behavioral abnormalities in humans. Young naïve progranulin deficient mice behaved normal in tests of short-term memory, anxiety, depression and nociception, but after peripheral nerve injury, they showed attention-deficit and depression-like behavior, over-activity, loss of shelter-seeking, reduced impulse control and compulsive feeding behavior, which did not occur in equally injured controls. Hence, only the interaction of 'pain x progranulin deficiency' resulted in the complex phenotype at young age, but neither pain nor progranulin deficiency alone. A deep proteome analysis of the prefrontal cortex and olfactory bulb revealed progranulin-dependent alterations of proteins involved in synaptic transport, including neurotransmitter transporters of the solute carrier superfamily. In particular, progranulin deficiency was associated with a deficiency of nuclear and synaptic zinc transporters (ZnT9/Slc30a9; ZnT3/Slc30a3) with low plasma zinc. Dietary zinc supplementation partly normalized the attention deficit of progranulin-deficient mice, which was in part reminiscent of autism-like and compulsive behavior of synaptic zinc transporter Znt3-knockout mice. Hence, the molecular studies point to defective zinc transport possibly contributing to progranulin-deficiency-associated psychopathology. Translated to humans, our data suggest that neuropathic pain may precipitate cognitive and psychopathological symptoms of an inherent, still silent neurodegenerative disease. Copyright © 2017. Published by Elsevier B.V.

Immunomodulatory properties and anti-apoptotic effects of zinc and melatonin in an experimental model of chronic Chagas disease.

PubMed

Brazão, Vânia; Filipin, Marina Del Vecchio; Santello, Fabricia Helena; Azevedo, Angela Palamin; Toldo, Míriam Paula Alonso; de Morais, Fabiana Rossetto; do Prado, José Clóvis

2015-05-01

The immunomodulatory effects of melatonin and zinc during chronic experimental Chagas' disease were studied. Early and late apoptosis by Annexin V-propidium iodide staining were evaluated. The expression of CD28, CD80, CD86, CD45RA and CD4(+)T and CD8(+)T cells were also evaluated by flow cytometry analysis. The combination of zinc and melatonin notably reduced the apoptotic ratios of splenic cells in the infected and treated animals when compared to untreated rats, during early and late stages of apoptosis. The percentages of CD8(+)T cells in Zn, Mel or Zn and Mel treated rats were reduced when compared to infected and untreated animals. Higher percentages of CD28 expression in CD4(+) and CD8(+) T cell populations were observed in control and infected Zn-treated group as compared to untreated ones. Zn, Mel or the combination of both did not induce any statistically significant differences for B cells when comparing to treated control and infected groups. Zinc or Mel-treated animals presented a lower expression of CD86 when compared to untreated counterparts. According to our data, this work strongly suggest that the modulation of the immune system operated by zinc and melatonin administration affected the balance among T cell immune response, apoptosis and expression of co-stimulatory molecules during chronic Trypanosoma cruzi infection, inducing important changes in the host's immune response against the parasite. Future experiments in this field should be focused in improving our understanding of the key mechanisms underlying the involvement of melatonin and zinc in the immune response during chronic Chagas' disease. Copyright © 2014 Elsevier GmbH. All rights reserved.

Zinc oxide nanoparticles as a substitute for zinc oxide or colistin sulfate: Effects on growth, serum enzymes, zinc deposition, intestinal morphology and epithelial barrier in weaned piglets

PubMed Central

Zhang, Ligen; Su, Weipeng; Ying, Zhixiong; He, Jintian; Zhang, Lili; Zhong, Xiang; Wang, Tian

2017-01-01

The objective of this study was to evaluate effects of zinc oxide nanoparticles (nano-ZnOs) as a substitute for colistin sulfate (CS) and/or zinc oxide (ZnO) on growth performance, serum enzymes, zinc deposition, intestinal morphology and epithelial barrier in weaned piglets. A total of 216 crossbred Duroc×(Landrace×Yorkshire) piglets weaned at 23 days were randomly assigned into 3 groups, which were fed with basal diets supplemented with 20 mg/kg CS (CS group), 20mg/kg CS+3000 mg/kg ZnO (CS+ZnO group), and 1200 mg/kg nano-ZnOs (nano-ZnO group) for 14 days. Results indicated that compared to CS group, supplementation of 1200 mg/kg nano-ZnOs (about 30 nm) significantly increased final body weight and average daily gain, and 3000 mg/kg ZnO plus colistin sulfate significantly increased average daily gain and decreased diarrhea rate in weaned piglets. There was no significant difference in growth performance and diarrhea rate between nano-ZnO and CS+ZnO groups. Supplementation of nano-ZnOs did not affect serum enzymes (glutamic oxalacetic transaminase, glutamic-pyruvic transaminase, and lactate dehydrogenase), but significantly increased plasma and tissue zinc concentrations (liver, tibia), improved intestinal morphology (increased duodenal and ileal villus length, crypt depth, and villus surface), enhanced mRNA expression of ZO-1 in ileal mucosa, and significantly decreased diamine oxidase activity in plasma, total aerobic bacterial population in MLN as compared to CS group. Effects of nano-ZnOs on serum enzymes, intestinal morphology, and mRNA expressions of tight junction were similar to those of high dietary ZnO plus colistin sulfate, while nano-ZnOs significantly reduced zinc concentrations of liver, tibia, and feces, and decreased total aerobic bacterial population in MLN as compared to CS+ZnO group. These results suggested that nano-ZnOs (1200 mg/kg) might be used as a substitute for colistin sulfate and high dietary ZnO in weaned piglets. PMID:28704517

The role of zinc deficiency-induced changes in the phospholipid-protein balance of blood serum in animal depression model by Raman, FTIR and UV-vis spectroscopy.

PubMed

Depciuch, J; Sowa-Kućma, M; Nowak, G; Szewczyk, B; Doboszewska, U; Parlinska-Wojtan, M

2017-05-01

Depression is a serious mental illness. To study the mechanisms of diseases and search for new, more effective therapies, animal models are used. Unfortunately, none of the available models does reflect all symptoms of depression. Zinc deficiency is proposed as a new animal model of depression. However, it has not been yet validated in a detailed manner. Recently, spectroscopic techniques are increasingly being used both in clinical and preclinical studies. Here we examined the effect of zinc deficiency and amitryptyline treatment on the phospholipid - protein balance in the blood serum of rats using Raman, Fourier Transform Infra Red (FTIR) and UV-vis technique. Male Sprague Dawley rats were fed with a zinc ample diet (ZnA, 50mg Zn/kg) or a zinc deficient diet (ZnD, 3mg Zn/kg) for 4 weeks. Then amitriptyline administration (AMI, 10mg/kg, i.p.) was started. After injecting the drug for 2-weeks, blood samples were collected and analyzed. It was found that zinc deficiency decreases both the level of phospholipids and proteins and also causes structural changes in their structures. In the ZnD group amitriptyline treatment influenced the protein level and structure. UV-vis spectroscopy combined with the second derivative calculated from the FTIR spectra provided information that the proteins in blood serum of rat fed with a low Zn diet regain their intact structure after amitriptyline medication. Simultaneously, the antidepressant therapy did not have any effect on the level of phospholipids in this group of rats. Additionally, our results show, that amitriptyline administration can change the structure of phospholipids in rats subjected to zinc ample diet. This altered structure of phospholipids was identified as shortening of carbon chains. Our findings indicate that the decreased level of zinc may be the cause of depressive disorders, as it leads to changes in the phospholipid-protein balance necessary for the proper functioning of the body. This study also shows possible new applications of spectroscopic techniques in the diagnosis of affective disorders, and maybe even identifies markers of depressive disorders. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Zinc oxide nanoparticles as a substitute for zinc oxide or colistin sulfate: Effects on growth, serum enzymes, zinc deposition, intestinal morphology and epithelial barrier in weaned piglets.

PubMed

Wang, Chao; Zhang, Ligen; Su, Weipeng; Ying, Zhixiong; He, Jintian; Zhang, Lili; Zhong, Xiang; Wang, Tian

2017-01-01

The objective of this study was to evaluate effects of zinc oxide nanoparticles (nano-ZnOs) as a substitute for colistin sulfate (CS) and/or zinc oxide (ZnO) on growth performance, serum enzymes, zinc deposition, intestinal morphology and epithelial barrier in weaned piglets. A total of 216 crossbred Duroc×(Landrace×Yorkshire) piglets weaned at 23 days were randomly assigned into 3 groups, which were fed with basal diets supplemented with 20 mg/kg CS (CS group), 20mg/kg CS+3000 mg/kg ZnO (CS+ZnO group), and 1200 mg/kg nano-ZnOs (nano-ZnO group) for 14 days. Results indicated that compared to CS group, supplementation of 1200 mg/kg nano-ZnOs (about 30 nm) significantly increased final body weight and average daily gain, and 3000 mg/kg ZnO plus colistin sulfate significantly increased average daily gain and decreased diarrhea rate in weaned piglets. There was no significant difference in growth performance and diarrhea rate between nano-ZnO and CS+ZnO groups. Supplementation of nano-ZnOs did not affect serum enzymes (glutamic oxalacetic transaminase, glutamic-pyruvic transaminase, and lactate dehydrogenase), but significantly increased plasma and tissue zinc concentrations (liver, tibia), improved intestinal morphology (increased duodenal and ileal villus length, crypt depth, and villus surface), enhanced mRNA expression of ZO-1 in ileal mucosa, and significantly decreased diamine oxidase activity in plasma, total aerobic bacterial population in MLN as compared to CS group. Effects of nano-ZnOs on serum enzymes, intestinal morphology, and mRNA expressions of tight junction were similar to those of high dietary ZnO plus colistin sulfate, while nano-ZnOs significantly reduced zinc concentrations of liver, tibia, and feces, and decreased total aerobic bacterial population in MLN as compared to CS+ZnO group. These results suggested that nano-ZnOs (1200 mg/kg) might be used as a substitute for colistin sulfate and high dietary ZnO in weaned piglets.

The effects of a lipid‐based nutrient supplement and antiretroviral therapy in a randomized controlled trial on iron, copper, and zinc in milk from HIV‐infected Malawian mothers and associations with maternal and infant biomarkers

PubMed Central

Shahab‐Ferdows, Setareh; Gertz, Erik; Flax, Valerie L.; Adair, Linda S.; Bentley, Margaret E.; Jamieson, Denise J.; Tegha, Gerald; Chasela, Charles S.; Kamwendo, Debbie; van der Horst, Charles M.; Allen, Lindsay H.

2017-01-01

Abstract We evaluated effects of antiretroviral (ARV) therapy and lipid‐based nutrient supplements (LNSs) on iron, copper, and zinc in milk of exclusively breastfeeding HIV‐infected Malawian mothers and their correlations with maternal and infant biomarkers. Human milk and blood at 2, 6, and 24 weeks post‐partum and blood during pregnancy (≤30 weeks gestation) were collected from 535 mothers/infant‐pairs in the Breastfeeding, Antiretrovirals, and Nutrition study. The participants received ARV, LNS, ARV and LNS, or no intervention from 0 to 28 weeks post‐partum. ARVs negatively affected copper and zinc milk concentrations, but only at 2 weeks, whereas LNS had no effect. Among all treatment groups, approximately 80–90% of copper and zinc and <50% of iron concentrations met the current adequate intake for infants at 2 weeks and only 1–19% at 24 weeks. Pregnancy haemoglobin was negatively correlated with milk iron at 2 and 6 weeks (r = −.18, p < .02 for both). The associations of the milk minerals with each other were the strongest correlations observed (r = .11–.47, p < .05 for all); none were found with infant biomarkers. At 2 weeks, moderately anaemic women produced milk higher in iron when ferritin was higher or TfR lower. At 6 weeks, higher maternal α‐1‐acid glycoprotein and C‐reactive protein were associated with higher milk minerals in mildly anaemic women. Infant TfR was lower when milk mineral concentrations were higher at 6 weeks and when mothers were moderately anaemic during pregnancy. ARV affects copper and zinc milk concentrations in early lactation, and maternal haemoglobin during pregnancy and lactation could influence the association between milk minerals and maternal and infant iron status and biomarkers of inflammation. PMID:28851037

U2AF1 mutations alter splice site recognition in hematological malignancies.

PubMed

Ilagan, Janine O; Ramakrishnan, Aravind; Hayes, Brian; Murphy, Michele E; Zebari, Ahmad S; Bradley, Philip; Bradley, Robert K

2015-01-01

Whole-exome sequencing studies have identified common mutations affecting genes encoding components of the RNA splicing machinery in hematological malignancies. Here, we sought to determine how mutations affecting the 3' splice site recognition factor U2AF1 alter its normal role in RNA splicing. We find that U2AF1 mutations influence the similarity of splicing programs in leukemias, but do not give rise to widespread splicing failure. U2AF1 mutations cause differential splicing of hundreds of genes, affecting biological pathways such as DNA methylation (DNMT3B), X chromosome inactivation (H2AFY), the DNA damage response (ATR, FANCA), and apoptosis (CASP8). We show that U2AF1 mutations alter the preferred 3' splice site motif in patients, in cell culture, and in vitro. Mutations affecting the first and second zinc fingers give rise to different alterations in splice site preference and largely distinct downstream splicing programs. These allele-specific effects are consistent with a computationally predicted model of U2AF1 in complex with RNA. Our findings suggest that U2AF1 mutations contribute to pathogenesis by causing quantitative changes in splicing that affect diverse cellular pathways, and give insight into the normal function of U2AF1's zinc finger domains. © 2015 Ilagan et al.; Published by Cold Spring Harbor Laboratory Press.

Facilitation of granule cell epileptiform activity by mossy fiber-released zinc in the pilocarpine model of temporal lobe epilepsy.

PubMed

Timofeeva, Olga; Nadler, J Victor

2006-03-17

Recurrent mossy fiber synapses in the dentate gyrus of epileptic brain facilitate the synchronous firing of granule cells and may promote seizure propagation. Mossy fiber terminals contain and release zinc. Released zinc inhibits the activation of NMDA receptors and may therefore oppose the development of granule cell epileptiform activity. Hippocampal slices from rats that had experienced pilocarpine-induced status epilepticus and developed a recurrent mossy fiber pathway were used to investigate this possibility. Actions of released zinc were inferred from the effects of chelation with 1 mM calcium disodium EDTA (CaEDTA). When granule cell population bursts were evoked by mossy fiber stimulation in the presence of 6 mM K(+) and 30 microM bicuculline, CaEDTA slowed the rate at which evoked bursting developed, but did not change the magnitude of the bursts once they had developed fully. The effects of CaEDTA were then studied on the pharmacologically isolated NMDA receptor- and AMPA/kainate receptor-mediated components of the fully developed bursts. CaEDTA increased the magnitude of NMDA receptor-mediated bursts and reduced the magnitude of AMPA/kainate receptor-mediated bursts. CaEDTA did not affect the granule cell bursts evoked in slices from untreated rats by stimulating the perforant path in the presence of bicuculline and 6 mM K(+). These results suggest that zinc released from the recurrent mossy fibers serves mainly to facilitate the recruitment of dentate granule cells into population bursts.

Fructose-1,6-bisphosphate aldolase (class II) is the primary site of nickel toxicity in Escherichia coli.

PubMed

Macomber, Lee; Elsey, Scott P; Hausinger, Robert P

2011-12-01

Nickel is toxic to all forms of life, but the mechanisms of cell damage are unknown. Indeed, environmentally relevant nickel levels (8 µM) inhibit wild-type Escherichia coli growth on glucose minimal medium. The same concentration of nickel also inhibits growth on fructose, but not succinate, lactate or glycerol; these results suggest that fructose-1,6-bisphosphate aldolase (FbaA) is a target of nickel toxicity. Cells stressed by 8 µM Ni(II) for 20 min lost 75% of their FbaA activity, demonstrating that FbaA is inactivated during nickel stress. Furthermore, overexpression of fbaA restored growth of an rcnA mutant in glucose minimal medium supplemented with 4 µM Ni(II), thus confirming that FbaA is a primary target of nickel toxicity. This class II aldolase has an active site zinc and a non-catalytic zinc nearby. Purified FbaA lost 80 % of its activity within 2 min when challenged with 8 µM Ni(II). Nickel-challenged FbaA lost 0.8 zinc and gained 0.8 nickel per inactivated monomer. FbaA mutants (D144A and E174A) affecting the non-catalytic zinc were resistant to nickel inhibition. These results define the primary site of nickel toxicity in E. coli as the class II aldolase FbaA through binding to the non-catalytic zinc site. © 2011 Blackwell Publishing Ltd.

Heat-transport mechanisms in molecular building blocks of inorganic/organic hybrid superlattices

NASA Astrophysics Data System (ADS)

Giri, Ashutosh; Niemelä, Janne-Petteri; Tynell, Tommi; Gaskins, John T.; Donovan, Brian F.; Karppinen, Maarit; Hopkins, Patrick E.

2016-03-01

Nanomaterial interfaces and concomitant thermal resistances are generally considered as atomic-scale planes that scatter the fundamental energy carriers. Given that the nanoscale structural and chemical properties of solid interfaces can strongly influence this thermal boundary conductance, the ballistic and diffusive nature of phonon transport along with the corresponding phonon wavelengths can affect how energy is scattered and transmitted across an interfacial region between two materials. In hybrid composites composed of atomic layer building blocks of inorganic and organic constituents, the varying interaction between the phononic spectrum in the inorganic crystals and vibronic modes in the molecular films can provide a new avenue to manipulate the energy exchange between the fundamental vibrational energy carriers across interfaces. Here, we systematically study the heat transfer mechanisms in hybrid superlattices of atomic- and molecular-layer-grown zinc oxide and hydroquinone with varying thicknesses of the inorganic and organic layers in the superlattices. We demonstrate ballistic energy transfer of phonons in the zinc oxide that is limited by scattering at the zinc oxide/hydroquinone interface for superlattices with a single monolayer of hydroquinone separating the thicker inorganic layers. The concomitant thermal boundary conductance across the zinc oxide interfacial region approaches the maximal thermal boundary conductance of a zinc oxide phonon flux, indicative of the contribution of long wavelength vibrations across the aromatic molecular monolayers in transmitting energy across the interface. This transmission of energy across the molecular interface decreases considerably as the thickness of the organic layers are increased.

Evaluation of serum trace mineral, vitamin D, and sex steroid hormone concentration, and survey data in llamas and alpacas with metacarpophalangeal and metatarsophalangeal hyperextension.

PubMed

Semevolos, Stacy A; Reed, Shannon K; Schultz, Loren G

2013-01-01

To characterize serum trace mineral, sex steroid hormone, and vitamin D concentrations and identify factors associated with metacarpophalangeal and metatarsophalangeal hyperextension in llamas and alpacas. Serum samples from 79 llamas and 15 alpacas and owner survey data for 573 llamas and 399 alpacas. Serum samples were stored at -20°C until analysis and were evaluated for trace mineral, vitamin D, estradiol, progesterone, and testosterone concentrations. Information regarding age of onset, number of affected animals in herd, feed and supplements given, type of housing, and management practices was obtained in an owner survey. Higher serum zinc and iron concentrations were associated with metacarpophalangeal and metatarsophalangeal hyperextension in camelids, compared with controls. In summer and fall months, vitamin D concentrations were significantly higher in affected camelids than controls. Overall prevalence was 13.3% in llamas, compared with 0.7% in alpacas. No management factors were found to be predictive of this condition. No other factors examined were associated with metacarpophalangeal and metatarsophalangeal hyperextension. Despite similar supplementation practices and environmental conditions between affected and unaffected animals, an association of high serum zinc, iron, and vitamin D concentrations in affected camelids, compared with controls, may indicate differences of intake or absorption of dietary supplements.

The binding of manganese(II) and zinc(II) to the synthetic oligonucleotide d(C-G-C-G-A-A-T-T-C-G-C-G)2. A 1H NMR study.

PubMed

Frøystein, N A; Sletten, E

1991-03-01

The interaction of the synthetic oligonucleotide d(C-G-C-G-A-A-T-T-C-G-C-G)2 with two different transition-metal ions has been investigated in aqueous solution by means of 1H NMR spectroscopy. The effects on the DNA due to the presence of manganese(II) or zinc(II) have been monitored by observing the paramagnetic broadening and diamagnetic shifts of the non-exchangeable proton resonance lines, respectively. The 1H NMR spectra acquired during the course of the manganese(II) titration show very distinct broadening effects on certain DNA resonance lines. Primarily, the H8 resonance of G4 is affected, but also the H5 and H6 resonances of C3 are clearly affected by the metal. The results imply that the binding of manganese(II) to DNA is sequence specific. The 1H spectra obtained during the zinc(II) titration reveal diamagnetic shift effects which largely conform with the paramagnetic broadening effects due to the presence of manganese(II), although this picture is somewhat more complex. The H8 resonance of G4 displays a clearly visible high-field shift, while for the other guanosine H8 protons this effect is absent. The H1' and H2' protons of C3 show an effect of similar strength, although in the opposite direction, while H5 and H6 of C3 are only slightly affected. Local differences in the structure of the DNA and the basicities of potential binding sites on different base steps in the sequence might account for the observed sequence selectivity.

Food prices and poverty negatively affect micronutrient intakes in Guatemala.

PubMed

Iannotti, Lora L; Robles, Miguel; Pachón, Helena; Chiarella, Cristina

2012-08-01

Limited empirical evidence exists for how economic conditions affect micronutrient nutrition. We hypothesized that increasing poverty and rising food prices would reduce consumption of high-quality "luxury" foods, leading to an increased probability of inadequacy for several nutrients. The 2006 Guatemala National Living Conditions Survey was analyzed. First, energy and nutrient intakes and adequacy levels were calculated. Second, the income-nutrient relationships were investigated by assessing disparities in intakes, determining income-nutrient elasticities, and modeling nutrient intakes by reductions in income. Third, the food price-nutrient relationships were explored through determination of price-nutrient elasticities and modeling 2 price scenarios: an increase in food prices similar in magnitude to the food price crisis of 2007-2008 and a standardized 10% increase across all food groups. Disparities in nutrient intakes were greatest for vitamin B-12 (0.38 concentration index) and vitamin A (0.30 concentration index); these nutrients were highly and positively correlated with income (r = 0.22-0.54; P < 0.05). Although the baseline probability of inadequacy was highest for vitamin B-12 (83%), zinc showed the greatest increase in probability of inadequacy as income was reduced, followed by folate and vitamin A. With rising food prices, zinc intake was most acutely affected under both scenarios (P < 0.05) and folate intake in the poorest quintile (+7 percentage points) under the 10% scenario. Price-nutrient elasticities were highest for vitamin B-12 and the meat, poultry, and fish group (-0.503) and for folate and the legumes group (-0.343). The economic factors of food prices and income differentially influenced micronutrient intakes in Guatemala, notably zinc and folate intakes.

[MORPHOFUNCTIONAL ADJUSTMENT VASCULAR AND CELLULAR COMPONENTS OF THE CEREBELLAR CORTEX IN EXPOSURE TO BODY SULFATES OF COPPER, ZINC AND IRON].

PubMed

Grintsova, N; Vasko, L; Kiptenko, L; Gortinsky, A; Murenets, N

2015-09-01

In order to analyze the morphological and morphometric reconstructions of the vascular bed, and Purkinje cells of the cerebellar cortex of rats in long-term action (for 90 days) on the body of sulphates of copper, zinc and iron, an experiment was conducted on 48 adult white male rats weighing 200-250 g in age 5-7 months. We used anatomical, morphometric, statistical and common methods of microanatomical research. It was found that the combined effect on the body of sulphates of copper and zinc, and iron in the cerebellum has enough expressive toxicity, which affects the condition of the vascular bed, and Purkinje cells. The degree of morphological transformations is in direct proportion to the duration of the experiment. In the pathogenesis of violations leading role played by hypoxia, develop signs of swelling of the cerebellar cortex with signs hemorrhagic infiltration, the severity of which is maximum on the 60th day of the experiment.

In vitro solubility of calcium, iron and zinc in relation to phytic acid levels in rice-based consumer products in China.

PubMed

Liang, Jianfen; Han, Bei-Zhong; Nout, M J Robert; Hamer, Robert J

2010-02-01

In vitro solubility of calcium, iron and zinc in relation to phytic acid (PA) levels in 30 commercial rice-based foods from China was studied. Solubility of minerals and molar ratios of PA to minerals varied with degrees of processing. In primary products, [PA]/[Ca] values were less than 5 and [PA]/[Fe] and [PA]/[Zn] similarly ranged between 5 and 74, with most values between 20 and 30. [PA]/[mineral] molar ratios in intensively processed products were lower. Solubility of calcium ranged from 0% to 87%, with the lowest in brown rice (12%) and the highest in infant foods (50%). Iron solubility in two-thirds of samples was lower than 30%, and that of zinc narrowly ranged from 6% to 30%. Solubility of minerals was not significantly affected by [PA]/[mineral]. At present, neither primary nor intensively processed rice-based products are good dietary sources of minerals. Improvements should be attempted by dephytinization, mineral fortification or, preferably, combination of both.

Research on plasma and saliva levels of some bivalent cations in patients with chronic periodontitis (salivary cations in chronic periodontitis).

PubMed

Manea, A; Nechifor, M

2014-01-01

The purpose of this study was to determine whether chronic periodontitis can stand behind modifications in the salivary and blood concentration of some bivalent cations (Calcium, Magnesium, Zinc and Copper). For this purpose, we formed a group of 30 adult patients with clinically onset chronic periodontitis, and another one of 30 healthy patients as control. Both groups were free from acute oral pathology and general illnesses. The groups were divided again according to the habit of smoking. Total saliva samples were obtained as "first time in the morning", then weighed and processed. Cations were read on Atomic Absorption Spectrophotometer and by Ion Chromatography (Magnesium). The same patients were required to undergo laboratory blood tests for Calcium, Magnesium and Zinc. Data obtained was normalised, then statistically interpreted using two-tailed heteroscedastic t-Student tests. Our data confirmed the existence of a connection between salivary calcium, magnesium, zinc and copper, and of blood magnesium, and chronic periodontitis. Salivary calcium and magnesium are affected by smoking.

Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

NASA Technical Reports Server (NTRS)

Sasscer, D. S.; Morgan, T. O.; Rivera, C.; Ernst, R.; Scott, A. C.; Summerson, T. J.

1982-01-01

Bare 3004 tubes, 7072 Alclad 3004 tubes, and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr). Pitting did not occur in bare 3003 and 3004 samples during the six month test. Pitting did occur to varying degrees in the Alclad and zinc diffusion treated material, but did not penetrate to the base metal. Biofouling countermeasures (intermittent chlorination and brushing) did not affect the corrosion rates to any significant extent. Intermittent chlorination at a level of 0.5 ppm for 28 minutes daily controlled microbiofouling of the samples but did not prevent the development of a macrobiofouling community in areas of the plumbing with low flow.

Novel hits for acetylcholinesterase inhibition derived by docking-based screening on ZINC database.

PubMed

Doytchinova, Irini; Atanasova, Mariyana; Valkova, Iva; Stavrakov, Georgi; Philipova, Irena; Zhivkova, Zvetanka; Zheleva-Dimitrova, Dimitrina; Konstantinov, Spiro; Dimitrov, Ivan

2018-12-01

The inhibition of the enzyme acetylcholinesterase (AChE) increases the levels of the neurotransmitter acetylcholine and symptomatically improves the affected cognitive function. In the present study, we searched for novel AChE inhibitors by docking-based virtual screening of the standard lead-like set of ZINC database containing more than 6 million small molecules using GOLD software. The top 10 best-scored hits were tested in vitro for AChE affinity, neurotoxicity, GIT and BBB permeability. The main pharmacokinetic parameters like volume of distribution, free fraction in plasma, total clearance, and half-life were predicted by previously derived models. Nine of the compounds bind to the enzyme with affinities from 0.517 to 0.735 µM, eight of them are non-toxic. All hits permeate GIT and BBB and bind extensively to plasma proteins. Most of them are low-clearance compounds. In total, seven of the 10 hits are promising for further lead optimisation. These are structures with ZINC IDs: 00220177, 44455618, 66142300, 71804814, 72065926, 96007907, and 97159977.

Non-invasive detection of iron deficiency by fluorescence measurement of erythrocyte zinc protoporphyrin in the lip

PubMed Central

Hennig, Georg; Homann, Christian; Teksan, Ilknur; Hasbargen, Uwe; Hasmüller, Stephan; Holdt, Lesca M.; Khaled, Nadia; Sroka, Ronald; Stauch, Thomas; Stepp, Herbert; Vogeser, Michael; Brittenham, Gary M.

2016-01-01

Worldwide, more individuals have iron deficiency than any other health problem. Most of those affected are unaware of their lack of iron, in part because detection of iron deficiency has required a blood sample. Here we report a non-invasive method to optically measure an established indicator of iron status, red blood cell zinc protoporphyrin, in the microcirculation of the lower lip. An optical fibre probe is used to illuminate the lip and acquire fluorescence emission spectra in ∼1 min. Dual-wavelength excitation with spectral fitting is used to distinguish the faint zinc protoporphyrin fluorescence from the much greater tissue background fluorescence, providing immediate results. In 56 women, 35 of whom were iron-deficient, the sensitivity and specificity of optical non-invasive detection of iron deficiency were 97% and 90%, respectively. This fluorescence method potentially provides a rapid, easy to use means for point-of-care screening for iron deficiency in resource-limited settings lacking laboratory infrastructure. PMID:26883939

Structure and optical properties of ZnO produced from microwave hydrothermal hydrolysis of tris(ethylenediamine)zinc nitrate complex

NASA Astrophysics Data System (ADS)

Mostafa, Nasser Y.; Heiba, Zein K.; Ibrahim, Mohamed M.

2015-01-01

ZnO powders were synthesized using a solution microwave hydrothermal hydrolysis process and tris(ethylenediamine)zinc nitrate {[Zn(en)3](NO3)2} (en = ethylenediamine) as a precursor. Hydrolysis of the precursor complex at different pH produced zinc oxide with a diversity of well-defined morphologies. The effect of hydrolysis pH values on the structural and optical properties has been explored using XRD, SEM, and UV-visible diffuse reflectance spectroscopy (DRS). At pH = 7.0, randomly dispersed rods were formed. Whereas flower-like morphologies were obtained by treating the complex precursor in water at pH = 10.0 and 12.0. The ZnO4 tetrahedrons are greatly affected by the pH value. The band gap decreased sharply with increasing the pH value from 7.0 to 10.0, then slightly decreased with further increasing the pH to 12.0. The relationship between band gap and both structure and surface defects of the samples is also discussed.

The efficacy of deferiprone on tissues aluminum removal and copper, zinc, manganese level in rabbits.

PubMed

Liu, Ping; Yao, Yu-Na; Wu, Shi-De; Dong, Huai-Jun; Feng, Guo-Chang; Yuan, Xiao-Yan

2005-08-01

The effect of 1,2-dimethyl-3-hydroxypyrid-4-one [deferiprone (DE)] on aluminum mobilization and elimination from tissues and serum as well as the influence on the excretion of trace elements, copper, zinc and manganese in rabbits was investigated. Sixteen New Zealand rabbits were randomly divided into three groups: control, Al-only and Al+DE. The Al-only and Al+DE animals received injections of Al2(SO43.18H2O 600 micromol Al/kg 5 days per week for 3 weeks. One week after the last Al injection the Al+DE rabbits were given deferiprone 750 micromol/kg/day intragastrically for 2 weeks. At the 42nd day the animals were sacrificed and the organs were taken and digested. Blood was taken from the ear artery three times (at the initiation of the experiment, before and after deferiprone administration). The aluminum and copper, zinc, manganese were determined by atomic absorption spectrophotometry. Our results showed that deferiprone could highly mobilize aluminum stores from tissues. At the end of experiment the aluminum contents of bone, kidney, liver and brain in Al+DE were significantly lower than that in Al-only rabbits. The copper, zinc, manganese contents were not affected by deferiprone administration.

Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials

PubMed Central

Azari, Z.; Pappalettere, C.

2015-01-01

The behaviour of materials is governed by the surrounding environment. The contact area between the material and the surrounding environment is the likely spot where different forms of degradation, particularly rust, may be generated. A rust prevention treatment, like bluing, inhibitors, humidity control, coatings, and galvanization, will be necessary. The galvanization process aims to protect the surface of the material by depositing a layer of metallic zinc by either hot-dip galvanizing or electroplating. In the hot-dip galvanizing process, a metallic bond between steel and metallic zinc is obtained by immersing the steel in a zinc bath at a temperature of around 460°C. Although the hot-dip galvanizing procedure is recognized to be one of the most effective techniques to combat corrosion, cracks can arise in the intermetallic δ layer. These cracks can affect the life of the coated material and decrease the lifetime service of the entire structure. In the present paper the mechanical response of hot-dip galvanized steel submitted to mechanical loading condition is investigated. Experimental tests were performed and corroborative numerical and analytical methods were then applied in order to describe both the mechanical behaviour and the processes of crack/cracks propagation in a bimaterial as zinc-coated material. PMID:27347531

Characterization and Prediction of Cracks in Coated Materials: Direction and Length of Crack Propagation in Bimaterials.

PubMed

Pruncu, C I; Azari, Z; Casavola, C; Pappalettere, C

2015-01-01

The behaviour of materials is governed by the surrounding environment. The contact area between the material and the surrounding environment is the likely spot where different forms of degradation, particularly rust, may be generated. A rust prevention treatment, like bluing, inhibitors, humidity control, coatings, and galvanization, will be necessary. The galvanization process aims to protect the surface of the material by depositing a layer of metallic zinc by either hot-dip galvanizing or electroplating. In the hot-dip galvanizing process, a metallic bond between steel and metallic zinc is obtained by immersing the steel in a zinc bath at a temperature of around 460°C. Although the hot-dip galvanizing procedure is recognized to be one of the most effective techniques to combat corrosion, cracks can arise in the intermetallic δ layer. These cracks can affect the life of the coated material and decrease the lifetime service of the entire structure. In the present paper the mechanical response of hot-dip galvanized steel submitted to mechanical loading condition is investigated. Experimental tests were performed and corroborative numerical and analytical methods were then applied in order to describe both the mechanical behaviour and the processes of crack/cracks propagation in a bimaterial as zinc-coated material.

Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide

NASA Technical Reports Server (NTRS)

Patterson, James D.; Li, Wei-Gang

1995-01-01

The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

The DNLZ/HEP zinc-binding subdomain is critical for regulation of the mitochondrial chaperone HSPA9

PubMed Central

Vu, Michael T; Zhai, Peng; Lee, Juhye; Guerra, Cecilia; Liu, Shirley; Gustin, Michael C; Silberg, Jonathan J

2012-01-01

Human mitochondrial DNLZ/HEP regulates the catalytic activity and solubility of the mitochondrial hsp70 chaperone HSPA9. Here, we investigate the role that the DNLZ zinc-binding and C-terminal subdomains play in regulating HSPA9. We show that truncations lacking portions of the zinc-binding subdomain (ZBS) do not affect the solubility of HSPA9 or its ATPase domain, whereas those containing the ZBS and at least 10 residues following this subdomain enhance chaperone solubility. Binding measurements further show that DNLZ requires its ZBS to form a stable complex with the HSPA9 ATPase domain, and ATP hydrolysis measurements reveal that the ZBS is critical for full stimulation of HSPA9 catalytic activity. We also examined if DNLZ is active in vivo. We found that DNLZ partially complements the growth of Δzim17Saccharomyces cerevisiae, and we discovered that a Zim17 truncation lacking a majority of the C-terminal subdomain strongly complements growth like full-length Zim17. These findings provide direct evidence that human DNLZ is a functional ortholog of Zim17. In addition, they implicate the pair of antiparallel β-strands that coordinate zinc in Zim17/DNLZ-type proteins as critical for binding and regulating hsp70 chaperones. PMID:22162012

The DNLZ/HEP zinc-binding subdomain is critical for regulation of the mitochondrial chaperone HSPA9.

PubMed

Vu, Michael T; Zhai, Peng; Lee, Juhye; Guerra, Cecilia; Liu, Shirley; Gustin, Michael C; Silberg, Jonathan J

2012-02-01

Human mitochondrial DNLZ/HEP regulates the catalytic activity and solubility of the mitochondrial hsp70 chaperone HSPA9. Here, we investigate the role that the DNLZ zinc-binding and C-terminal subdomains play in regulating HSPA9. We show that truncations lacking portions of the zinc-binding subdomain (ZBS) do not affect the solubility of HSPA9 or its ATPase domain, whereas those containing the ZBS and at least 10 residues following this subdomain enhance chaperone solubility. Binding measurements further show that DNLZ requires its ZBS to form a stable complex with the HSPA9 ATPase domain, and ATP hydrolysis measurements reveal that the ZBS is critical for full stimulation of HSPA9 catalytic activity. We also examined if DNLZ is active in vivo. We found that DNLZ partially complements the growth of Δzim17 Saccharomyces cerevisiae, and we discovered that a Zim17 truncation lacking a majority of the C-terminal subdomain strongly complements growth like full-length Zim17. These findings provide direct evidence that human DNLZ is a functional ortholog of Zim17. In addition, they implicate the pair of antiparallel β-strands that coordinate zinc in Zim17/DNLZ-type proteins as critical for binding and regulating hsp70 chaperones. Copyright © 2011 The Protein Society.

The cellular magnetic response and biocompatibility of biogenic zinc- and cobalt-doped magnetite nanoparticles

NASA Astrophysics Data System (ADS)

Moise, Sandhya; Céspedes, Eva; Soukup, Dalibor; Byrne, James M.; El Haj, Alicia J.; Telling, Neil D.

2017-01-01

The magnetic moment and anisotropy of magnetite nanoparticles can be optimised by doping with transition metal cations, enabling their properties to be tuned for different biomedical applications. In this study, we assessed the suitability of bacterially synthesized zinc- and cobalt-doped magnetite nanoparticles for biomedical applications. To do this we measured cellular viability and activity in primary human bone marrow-derived mesenchymal stem cells and human osteosarcoma-derived cells. Using AC susceptibility we studied doping induced changes in the magnetic response of the nanoparticles both as stable aqueous suspensions and when associated with cells. Our findings show that the magnetic response of the particles was altered after cellular interaction with a reduction in their mobility. In particular, the strongest AC susceptibility signal measured in vitro was from cells containing high-moment zinc-doped particles, whilst no signal was observed in cells containing the high-anisotropy cobalt-doped particles. For both particle types we found that the moderate dopant levels required for optimum magnetic properties did not alter their cytotoxicity or affect osteogenic differentiation of the stem cells. Thus, despite the known cytotoxicity of cobalt and zinc ions, these results suggest that iron oxide nanoparticles can be doped to sufficiently tailor their magnetic properties without compromising cellular biocompatibility.

The cellular magnetic response and biocompatibility of biogenic zinc- and cobalt-doped magnetite nanoparticles

PubMed Central

Moise, Sandhya; Céspedes, Eva; Soukup, Dalibor; Byrne, James M.; El Haj, Alicia J.; Telling, Neil D.

2017-01-01

The magnetic moment and anisotropy of magnetite nanoparticles can be optimised by doping with transition metal cations, enabling their properties to be tuned for different biomedical applications. In this study, we assessed the suitability of bacterially synthesized zinc- and cobalt-doped magnetite nanoparticles for biomedical applications. To do this we measured cellular viability and activity in primary human bone marrow-derived mesenchymal stem cells and human osteosarcoma-derived cells. Using AC susceptibility we studied doping induced changes in the magnetic response of the nanoparticles both as stable aqueous suspensions and when associated with cells. Our findings show that the magnetic response of the particles was altered after cellular interaction with a reduction in their mobility. In particular, the strongest AC susceptibility signal measured in vitro was from cells containing high-moment zinc-doped particles, whilst no signal was observed in cells containing the high-anisotropy cobalt-doped particles. For both particle types we found that the moderate dopant levels required for optimum magnetic properties did not alter their cytotoxicity or affect osteogenic differentiation of the stem cells. Thus, despite the known cytotoxicity of cobalt and zinc ions, these results suggest that iron oxide nanoparticles can be doped to sufficiently tailor their magnetic properties without compromising cellular biocompatibility. PMID:28045082

Sequestration of zinc from zinc oxide nanoparticles and life cycle effects in the sediment dweller amphipod Corophium volutator.

PubMed

Fabrega, Julia; Tantra, Ratna; Amer, Aisha; Stolpe, Bjorn; Tomkins, Jordan; Fry, Tony; Lead, Jamie R; Tyler, Charles R; Galloway, Tamara S

2012-01-17

We studied the effects of ZnO nanoparticles [ZnO NPs, primary particle size 35 ± 10 nm (circular diameter, TEM)], bulk [160 ± 81 nm (circular diameter, TEM)], and Zn ions (from ZnCl(2)) on mortality, growth, and reproductive endpoints in the sediment dwelling marine amphipod Corophium volutator over a complete lifecycle (100 days). ZnO NPs were characterized by size, aggregation, morphology, dissolution, and surface properties. ZnO NPs underwent aggregation and partial dissolution in the seawater exposure medium, resulting in a size distribution that ranged in size from discrete nanoparticles to the largest aggregate of several micrometers. Exposure via water to all forms of zinc in the range of 0.2-1.0 mg L(-1) delayed growth and affected the reproductive outcome of the exposed populations. STEM-EDX analysis was used to characterize insoluble zinc precipitates (sphaerites) of high sulfur content, which accumulated in the hepatopancreas following exposures. The elemental composition of the sphaerites did not differ for ZnO NP, Zn(2+), and bulk ZnO exposed organisms. These results provide an illustration of the comparable toxicity of Zn in bulk, soluble, and nanoscale forms on critical lifecycle parameters in a sediment dwelling organism.

Quantification and Simulation of Metal Loading to the Upper Animas River, Eureka to Silverton, San Juan County, Colorado, September 1997 and August 1998

USGS Publications Warehouse

Paschke, Suzanne S.; Kimball, Briant A.; Runkel, Robert L.

2005-01-01

Drainage from abandoned and inactive mines and from naturally mineralized areas in the San Juan Mountains of southern Colorado contributes metals to the upper Animas River near Silverton, Colorado. Tracer-injection studies and associated synoptic sampling were performed along two reaches of the upper Animas River to develop detailed profiles of stream discharge and to locate and quantify sources of metal loading. One tracer-injection study was performed in September 1997 on the Animas River reach from Howardsville to Silverton, and a second study was performed in August 1998 on the stream reach from Eureka to Howardsville. Drainage in the upper Animas River study reaches contributed aluminum, calcium, copper, iron, magnesium, manganese, sulfate, and zinc to the surface-water system in 1997 and 1998. Colloidal aluminum, dissolved copper, and dissolved zinc were attenuated through a braided stream reach downstream from Eureka. Instream dissolved copper concentrations were lower than the State of Colorado acute and chronic toxicity standards downstream from the braided reach to Silverton. Dissolved iron load and concentrations increased downstream from Howardsville and Arrastra Gulch, and colloidal iron remained constant at low concentrations downstream from Howardsville. Instream sulfate concentrations were lower than the U.S. Environmental Protection Agency's secondary drinking-water standard of 250 milligrams per liter throughout the two study reaches. Elevated zinc concentrations are the primary concern for aquatic life in the upper Animas River. In the 1998 Eureka to Howardsville study, instream dissolved zinc load increased downstream from the Forest Queen mine, the Kittimack tailings, and Howardsville. In the 1997 Howardsville to Silverton study, there were four primary areas where zinc load increased. First, was the increase downstream from Howardsville and abandoned mining sites downstream from the Cunningham Gulch confluence, which also was measured during the 1998 study. The second affected reach was downstream from Arrastra Gulch, where the increase in zinc load seems related to a series of right-bank inflows with low pH Quantification and Simulation of Metal Loading to the Upper Animas River, Eureka to Silverton, San Juan County, Colorado, September 1997 and August 1998By Suzanne S. Paschke, Briant A. Kimball, and Robert L. Runkeland elevated dissolved zinc concentrations. A third increase in zinc load occurred 6,100 meters downstream from the 1997 injection site and may have been from ground-water discharge with elevated zinc concentrations based on mass-loading graphs and the lack of visible inflow in the reach. A fourth but lesser dissolved zinc load increase occurred downstream from tailings near the Lackawanna Mill. Results of the tracer-injection studies and the effects of potential remediation were analyzed using the one- dimensional stream-transport computer code OTIS. Based on simulation results, instream zinc concentrations downstream from the Kittimack tailings to upstream from Arrastra Gulch would approach 0.16 milligram per liter (the upper limit of acute toxicity for some sensitive aquatic species) if zinc inflow concentrations were reduced by 75 percent in the stream reaches receiving inflow from the Forest Queen mine, the Kittimack tailings, and downstream from Howardsville. However, simulated zinc concentrations downstream from Arrastra Gulch were higher than approximately 0.30 milligram per liter due to numerous visible inflows and assumed ground-water discharge with elevated zinc concentrations in the lower part of the study reach. Remediation of discrete visible inflows seems a viable approach to reducing zinc inflow loads to the upper Animas River. Remediation downstream from Arrastra Gulch is more complicated because ground-water discharge with elevated zinc concentrations seems to contribute to the instream zinc load.

Optimization of the optical and electrical properties of electron beam evaporated aluminum-doped zinc oxide films for opto-electronic applications

NASA Astrophysics Data System (ADS)

Ali, H. M.; Abd El-Raheem, M. M.; Megahed, N. M.; Mohamed, H. A.

2006-08-01

Aluminum-doped zinc oxide (AZO) thin films have been deposited by electron beam evaporation technique on glass substrates. The structural, electrical and optical properties of AZO films have been investigated as a function of annealing temperature. It was observed that the optical properties such as transmittance, reflectance, optical band gap and refractive index of AZO films were strongly affected by annealing temperature. The transmittance values of 84% in the visible region and 97% in the NIR region were obtained for AZO film annealed at 475 °C. The room temperature electrical resistivity of 4.6×10-3 Ω cm has been obtained at the same temperature of annealing. It was found that the calculated refractive index has been affected by the packing density of the thin films, whereas, the high annealing temperature gave rise to improve the homogeneity of the films. The single-oscillator model was used to analyze the optical parameters such as the oscillator and dispersion energies.

Stability and electronic properties of oxygen-doped ZnS polytypes: DFTB study

NASA Astrophysics Data System (ADS)

Popov, Ilya S.; Vorokh, Andrey S.; Enyashin, Andrey N.

2018-06-01

Synthesis from aqueous solutions is an affordable method for fabrication of II-VI semiconductors. However, application of this method often imposes a disorder of crystal lattice, manifesting as a rich variety of polytypes arising from wurtzite and zinc blende phases. The origin of this disordering still remains debatable. Here, the influence of the most likely impurity at water environment - substitutional oxygen - on the polytypic equilibrium of zinc sulphide is studied by means of density-functional tight-binding method. According to calculations, the inclusion of such oxygen does not affect the polytypic equilibrium. Apart of thermodynamic stability, the electronic and elastic properties of ZnS polytypes are studied as the function of oxygen distribution.

Synthesis and characterization of copper zinc oxide nanoparticles obtained via metathesis process

NASA Astrophysics Data System (ADS)

Phoohinkong, Weerachon; Foophow, Tita; Pecharapa, Wisanu

2017-09-01

Copper-doped zinc oxide nanoparticles were successfully synthesized by grinding copper acetate and zinc acetate powder with different starting molar ratios in combined with sodium hydroxide. The effect of initial copper and zinc molar ratios on the product samples was investigated and discussed. Relevant ligand coordination type of reactant acetate salt precursors and product samples were investigated by Fourier transform infrared spectroscopy (FTIR). The particle shapes and surface morphologies were characterized by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Phase structures of prepared samples were studied by x-ray powder diffraction (XRD) and x-ray absorption near-edge spectroscopy (XANES) was applied to investigate the local structure of Cu and Zn environment atoms. The results demonstrate that the, particle size of as-synthesized products affected by copper concentration in the precursor trend to gradually decreases from nanorod shape with diameter around 50-100 nm to irregular particle structure around 5 nm associated with an increase in the concentration of copper in precursor. Moreover, it is noticed that shape and morphology of the products are strongly dependent on Cu:Zn ratios during the synthesis. Nanocrystallines Cu-doped ZnO by the substitution in Zn site with a high crystallization degree of hexagonal wurtzite structure were obtained. This synthesis technique is suggested as a potential effective technique for preparing copper zinc oxide nanoparticles with various atomic ratio in wide range of applications. Contribution at the 4th Southeast Asia Conference on Thermoelectrics 2016 (SACT 2016), 15-18 December 2016, Da Nang City, Vietnam.

Multi-year and short-term responses of soil ammonia-oxidizing prokaryotes to zinc bacitracin, monensin, and ivermectin, singly or in combination.

PubMed

Magda, Konopka; Hugh A L, Henry; Romain, Marti; Edward, Topp

2015-03-01

A field experiment was initiated whereby a series of replicated plots received annual applications of ivermectin, monensin, and zinc bacitracin, either singly or in a mixture. Pharmaceuticals were added at concentrations of 0.1 mg/kg soil or 10 mg/kg soil. The authors collected soil samples in 2013, before and after the fourth annual application of pharmaceuticals. In addition, a 30-d laboratory experiment was undertaken with the same soil and same pharmaceuticals, but at concentrations of 100 mg/kg soil. The impact of the pharmaceuticals on nitrification rates, on the abundance of ammonia-oxidizing bacteria (AOB), and on the abundance of ammonia-oxidizing archaea (AOA) was assessed. None of the pharmaceuticals at 0.1 mg/kg had any effect on nitrification. Referenced to control soil, nitrification was accelerated in soil exposed to 100 mg/kg zinc bacitracin or 10 mg/kg of the pharmaceutical mixture, but none of the treatments inhibited nitrification. Neither AOB abundance nor AOA abundance was affected by the pharmaceuticals at 0.1 mg/kg. At 10 mg/kg, monensin, zinc bacitracin, and a mixture of all 3 pharmaceuticals suppressed the abundance of AOB, and zinc bacitracin and the mixture increased AOA abundance. The decrease in AOB abundance and increase in AOA abundance when exposed to 10 mg/kg soil suggests that AOB are more sensitive to these chemicals and that AOA populations can expand to occupy the partially vacated niche. Published 2014 SETAC.

Zinc Absorption from Milk Is Affected by Dilution but Not by Thermal Processing, and Milk Enhances Absorption of Zinc from High-Phytate Rice in Young Dutch Women.

PubMed

Talsma, Elise F; Moretti, Diego; Ly, Sou Chheng; Dekkers, Renske; van den Heuvel, Ellen Ghm; Fitri, Aditia; Boelsma, Esther; Stomph, Tjeerd Jan; Zeder, Christophe; Melse-Boonstra, Alida

2017-06-01

Background: Milk has been suggested to increase zinc absorption. The effect of processing and the ability of milk to enhance zinc absorption from other foods has not been measured directly in humans. Objective: We aimed to assess zinc absorption from 1 ) milk undergoing various processing and preparatory steps and 2 ) from intrinsically labeled high-phytate rice consumed with milk or water. Methods: Two randomized crossover studies were conducted in healthy young women [age:18-25 y; body mass index (in kg/m 2 ): 20-25]: 1 ) a milk study ( n = 19) comparing the consumption of 800 mL full-fat ultra-high temperature (UHT) milk [heat-treated milk (HTM)], full-fat UHT milk diluted 1:1 with water [heat-treated milk and water (MW)], water, or unprocessed (raw) milk (UM), each extrinsically labeled with 67 Zn, and 2 ) a rice study ( n = 18) comparing the consumption of 90 g intrinsically 67 Zn-labeled rice with 600 mL of water [rice and water (RW)] or full-fat UHT milk [rice and milk (RM)]. The fractional absorption of zinc (FAZ) was measured with the double-isotope tracer ratio method. In vitro, we assessed zinc extraction from rice blended into water, UM, or HTM with or without phytate. Results: FAZ from HTM was 25.5% (95% CI: 21.6%, 29.4%) and was not different from UM (27.8%; 95% CI: 24.2%, 31.4%). FAZ from water was higher (72.3%; 95% CI: 68.7%, 75.9%), whereas FAZ from MW was lower (19.7%; 95% CI: 17.5%, 21.9%) than HTM and UM (both P < 0.01). FAZ from RM (20.7%; 95% CI: 18.8%, 22.7%) was significantly higher than from RW (12.8%; 95% CI: 10.8%, 14.6%; P < 0.01). In vitro, HTM and UM showed several orders of magnitude higher extraction of zinc from rice with HTM than from rice with water at various phytate concentrations. Conclusions: Milk enhanced human FAZ from high-phytate rice by 62% compared with water. Diluting milk with water decreases its absorption-enhancing proprieties, whereas UHT processing does not. This trial was registered at the Dutch trial registry as NTR4267 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4267). © 2017 American Society for Nutrition.

Modelling environment contamination with heavy metals in flathead grey mullet Mugil cephalus and upper sediments from north African coasts of the Mediterranean Sea.

PubMed

Ouali, Naouel; Belabed, Bourhane-Eddine; Chenchouni, Haroun

2018-05-18

Heavy metals are a serious hazard for aquatic ecosystems and human health. They negatively affect aquatic life functioning through accumulation resulting physiological/growth disturbances in aquatic lifeforms. This survey focused on the assessment of heavy metal pollution in the Gulf of Annaba (northeastern Algeria), the largest and most diversified industrial hub in Africa, using a multi-compartment approach (water-sediment-biota). The study aims to characterize the spatiotemporal variation of trace metal (TM) contamination and its effects on the growth of the Flathead grey mullet (Mugil cephalus). It reviewed TM concentrations in upper sediments and organs of M. cephalus from various hydrosystems worldwide. Five sites distributed along the Gulf were sampled to determine water physicochemical parameters as well as the contamination of surficial sediments and muscles of M. cephalus by zinc, copper, lead, cadmium and mercury. The spatiotemporal variations of the measured parameters were tested and discussed following the synergetic effects of water, sediment and muscle variables on fish biometrics. The sediments at the Port, Joinoville and Sidi-Salem sites were classified as heavily polluted by lead, copper, zinc and cadmium, whereas only at the Port by mercury. Muscular lead concentrations exceeded international standard values in Joinoville and Port, and zinc in Port. The increase of water dissolved oxygen induced a significant decrease in sediment TM. The increase of sediment TM caused a significant increase in muscle TM levels. The S-shaped logistic models indicated that muscle contaminations reached a saturation plateaus following the current sediment pollution. TM concentrations in fish muscles negatively affected fish weight, but only copper and cadmium significantly influenced fish length. The consumption of fish from the Port, Joinoville and Sidi-Salem can be dangerous because concentrations of lead, zinc and cadmium exceeded the international standards. This study validates the effectiveness of biomonitoring using M. cephalus as bioindicator in polluted coasts. Copyright © 2018 Elsevier B.V. All rights reserved.

In vitro and in vivo effects of zinc on cytokine signalling in human T cells.

PubMed

Varin, Audrey; Larbi, Anis; Dedoussis, George V; Kanoni, Stavroula; Jajte, Jolanta; Rink, Lothar; Monti, Daniela; Malavolta, Marco; Marcellini, Fiorella; Mocchegiani, Eugenio; Herbein, Georges; Fulop, Tamas

2008-05-01

Aging is associated with changes in the immune response which are collectively called immunosenescence. The changes mainly affect the adaptive immune response and especially the T cell-mediated cellular immune response. There are a few data indicating that the cytokine signalling in T cells is altered with aging. Zinc has been specifically shown to have potent immunomodulatory effects. The aim of the present work was to study the IL-2 and IL-6 cytokine signalling and activation induced cell death (AICD) in T cells of elderly subjects of various ages and from various European countries. These experiments were performed in the frame of European Community financed project called ZINCAGE "Nutritional zinc, oxidative stress and immunosenescence: biochemical, genetic and lifestyle implications for healthy ageing", assembling 17 laboratories from 8 countries through Europe. The study was carried out in a total of 312 French and a group of 201 (26 from Italy, 63 from France, 57 from Greece, 24 from Poland and 30 from Germany) healthy non-institutionalized men and women older than 60 years of age, with available dietary data. Human peripheral blood mononuclear cells (PBMC) were obtained from heparinized blood and were stimulated in vitro by IL-2 or IL-6 for various periods and the phosphorylation of STAT3 and STAT5 was measured by FACScan. The activation induced cell death (AICD) was measured after anti-CD3 and CD28 restimulation for 48h by using the Annexin:FITC Apoptosis Kit. We found that there is an IL-2 signalling defect with aging up to 90 years of age which cannot be modulated by zinc. In contrast at 90 years and over the zinc could reverse the negative signalling effect of IL-2. There is also a signalling defect for STAT3 and STAT5 activation in T cells under IL-6 stimulation with aging and the zinc supplementation could potentiate only the STAT5 activation in the age-group 90 years and over. Studying signalling in PBL from different countries we detected less activation in T cells of subjects from France and the most changes occurred in T cells of subjects from Poland, suggesting no correlation with the plasma zinc status observed in these countries. In vivo zinc supplementation had no effect on IL-2 and IL-6-modulated STAT3 and STAT5 activation. Zinc added in vitro to these T cells even inhibited the stimulation either by IL-2 or by IL-6. Zinc supplementation improved the susceptibility of T cells to AICD in both age-groups, with more efficiency in later ages. Our results suggest that zinc can have a potent immunomodulatory effect via the modulation of cytokine signalling and AICD, however this effect depends on the function and the activation status of the T cells.

Zinc Supplementation, via GPR39, Upregulates PKCζ to Protect Intestinal Barrier Integrity in Caco-2 Cells Challenged by Salmonella enterica Serovar Typhimurium.

PubMed

Shao, Yu-Xin; Lei, Zhao; Wolf, Patricia G; Gao, Yan; Guo, Yu-Ming; Zhang, Bing-Kun

2017-07-01

Background: Zinc has been shown to improve intestinal barrier function against Salmonella enterica serovar Typhimurium ( S. typhimurium ) infection, but the mechanisms involved in this process remain undefined. Objective: We aimed to explore the roles of G protein-coupled receptor (GPR)39 and protein kinase Cζ (PKCζ) in the regulation by zinc of intestinal barrier function. Methods: A Transwell Caco-2 monolayer was pretreated with 0, 50, or 100 μM Zn and then incubated with S. typhimurium for 0-6 h. Afterward, cells silenced by the small interfering RNA for GPR39 or PKCζ were pretreated with 100 μM Zn and incubated with S. typhimurium for 3 h. Finally, transepithelial electrical resistance (TEER), permeability, tight junction (TJ) proteins, and signaling molecules GPR39 and PKCζ were measured. Results: Compared with controls, S. typhimurium decreased TEER by 62.3-96.2% at 4-6 h ( P < 0.001), increased ( P < 0.001) permeability at 6 h, and downregulated ( P < 0.05) TJ protein zonula occludens (ZO)-1 and occludin by 104-123%, as well as Toll-like receptor 2 and PKCζ by 35.1% and 75.2%, respectively. Compared with S. typhimurium- challenged cells, 50 and 100 μM Zn improved TEER by 26.3-60.9% at 4-6 h ( P < 0.001) and decreased ( P < 0.001) permeability and bacterial invasion at 6 h. A total of 100 μM Zn increased ZO-1, occludin, GPR39, and PKCζ 0.72- to 1.34-fold ( P < 0.05); however, 50 μM Zn did not affect ZO-1 or occludin ( P > 0.1). Silencing GPR39 decreased ( P < 0.05) zinc-activated PKCζ and blocked ( P < 0.05) the promotion of zinc on epithelial integrity. Furthermore, silencing PKCζ counteracted the protective effect of zinc on epithelial integrity but did not inhibit GPR39 ( P = 0.138). Conclusion: We demonstrated that zinc upregulates PKCζ by activating GPR39 to enhance the abundance of ZO-1, thereby improving epithelial integrity in S. typhimurium- infected Caco-2 cells. © 2017 American Society for Nutrition.

Autosomal-Recessive Intellectual Disability with Cerebellar Atrophy Syndrome Caused by Mutation of the Manganese and Zinc Transporter Gene SLC39A8.

PubMed

Boycott, Kym M; Beaulieu, Chandree L; Kernohan, Kristin D; Gebril, Ola H; Mhanni, Aziz; Chudley, Albert E; Redl, David; Qin, Wen; Hampson, Sarah; Küry, Sébastien; Tetreault, Martine; Puffenberger, Erik G; Scott, James N; Bezieau, Stéphane; Reis, André; Uebe, Steffen; Schumacher, Johannes; Hegele, Robert A; McLeod, D Ross; Gálvez-Peralta, Marina; Majewski, Jacek; Ramaekers, Vincent T; Nebert, Daniel W; Innes, A Micheil; Parboosingh, Jillian S; Abou Jamra, Rami

2015-12-03

Manganese (Mn) and zinc (Zn) are essential divalent cations used by cells as protein cofactors; various human studies and animal models have demonstrated the importance of Mn and Zn for development. Here we describe an autosomal-recessive disorder in six individuals from the Hutterite community and in an unrelated Egyptian sibpair; the disorder is characterized by intellectual disability, developmental delay, hypotonia, strabismus, cerebellar atrophy, and variable short stature. Exome sequencing in one affected Hutterite individual and the Egyptian family identified the same homozygous variant, c.112G>C (p.Gly38Arg), affecting a conserved residue of SLC39A8. The affected Hutterite and Egyptian individuals did not share an extended common haplotype, suggesting that the mutation arose independently. SLC39A8 is a member of the solute carrier gene family known to import Mn, Zn, and other divalent cations across the plasma membrane. Evaluation of these two metal ions in the affected individuals revealed variably low levels of Mn and Zn in blood and elevated levels in urine, indicating renal wasting. Our findings identify a human Mn and Zn transporter deficiency syndrome linked to SLC39A8, providing insight into the roles of Mn and Zn homeostasis in human health and development. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Differential iron distribution in seeds of two closely related legume species

USDA-ARS?s Scientific Manuscript database

The World Health Organization states that the lack of micronutrients such as zinc and iron represents a major threat to the health and development of populations around the world. Iron deficiency affects over 2 billion people, in particular children and pregnant women in developing countries. A comm...

Battery Safety Basics

ERIC Educational Resources Information Center

Roy, Ken

2010-01-01

Batteries commonly used in flashlights and other household devices produce hydrogen gas as a product of zinc electrode corrosion. The amount of gas produced is affected by the batteries' design and charge rate. Dangerous levels of hydrogen gas can be released if battery types are mixed, batteries are damaged, batteries are of different ages, or…

CaSO4 Scale Inhibition by a Trace Amount of Zinc Ion in Piping System

NASA Astrophysics Data System (ADS)

Mangestiyono, W.; Sutrisno

2017-05-01

Usually, a small steam generator is not complemented by equipment such as demineralization and chlorination process apparatus since the economic aspect was a precedence. Such phenomenon was uncovered in a case study of green tea industrial process in which the boiler capacity was not more than 1 ton/hour. The operation of the small boiler affected the scaling process in its piping system. In a year operation, there was already a large scale of calcium attached to the inner surface of the pipe. Such large scale formed a layer and decreased the overall heat transfer coefficient, prolonged the process time and decreased the production. The aim of the current research was to solve the problem through a laboratory research to inhibit the CaSO4 scale formation by the addition of trace amounts of zinc ion. This research was conducted through a built in-house experimental rig which consisted of a dosing pump for controlling the flow rate and a thermocouple to control the temperature. Synthesis solution was prepared with 3,500 ppm concentration of CaCl2 and Na2SO4. The concentration of zinc was set at 0.00; 5.00 and 10.00 ppm. The data found were characterized by scanning electron microscopy (SEM) to analyze crystal polymorph as the influence of zinc ion addition. The induction time was also investigated to analyze the nucleation time, and it was found on the 9th, 13th, and 19th minute of the zinc ion addition of 0.00, 5.00 and 10.00 ppm. After running for a four-hour duration, the scale grow-rate was found to be 5.799; 5.501 and 4.950 × 10-3 gr/min for 0.00; 5.00 and 10.00 ppm of zinc addition at 50 °C.

Effect of in ovo supplementation of nano forms of zinc, copper, and selenium on post-hatch performance of broiler chicken.

PubMed

Joshua, P Patric; Valli, C; Balakrishnan, V

2016-03-01

Nanoparticles can bypass conventional physiological ways of nutrient distribution and transport across tissue and cell membranes, as well as protect compounds against destruction prior to reaching their targets. In ovo administration of nanoparticles, may be seen as a new method of nano-nutrition, providing embryos with an additional quantity of nutrients. The aim of the study is to examine the effect of in ovo supplementation of nano forms of zinc, copper and selenium on the hatchability and post hatch performance of broiler chicken. Nano form of zinc at 20, 40, 60 and 80 µg/egg, nano form of copper at 4, 8, 12 and 16 µg/egg and nano form of selenium at 0.075, 0.15, 0.225 and 0.3 µg/egg were in ovo supplemented (18(th) day incubation, amniotic route) in fertile broiler eggs. Control group in ovo fed with normal saline alone was also maintained. Each treatment had thirty replicates. Parameters such as hatchability, hatch weight and post hatch performance were studied. In ovo feeding of nano minerals were not harmful to the developing embryo and did not influence the hatchability. Significantly (p<0.05) best feed efficiency for nano forms of zinc (2.16), copper (2.46) and selenium (2.51) were observed, when 40, 4 and 0.225 µg/egg respectively were in ovo supplemented. Except in nano form of copper at 12 µg per egg which had significantly (p<0.05) highest breast muscle percentage there was no distinct trend to indicate that dressing percentage or breast muscle yield was influenced in other treatments. Nano forms of zinc, copper and selenium can be prepared at laboratory conditions. In ovo feeding of nano forms of zinc, copper and selenium at 18(th) day of incubation through amniotic route does not harm the developing embryo, does not affect hatchability.

Effect of in ovo supplementation of nano forms of zinc, copper, and selenium on post-hatch performance of broiler chicken

PubMed Central

Joshua, P. Patric; Valli, C.; Balakrishnan, V.

2016-01-01

Background and Aim: Nanoparticles can bypass conventional physiological ways of nutrient distribution and transport across tissue and cell membranes, as well as protect compounds against destruction prior to reaching their targets. In ovo administration of nanoparticles, may be seen as a new method of nano-nutrition, providing embryos with an additional quantity of nutrients. The aim of the study is to examine the effect of in ovo supplementation of nano forms of zinc, copper and selenium on the hatchability and post hatch performance of broiler chicken. Materials and Methods: Nano form of zinc at 20, 40, 60 and 80 µg/egg, nano form of copper at 4, 8, 12 and 16 µg/egg and nano form of selenium at 0.075, 0.15, 0.225 and 0.3 µg/egg were in ovo supplemented (18th day incubation, amniotic route) in fertile broiler eggs. Control group in ovo fed with normal saline alone was also maintained. Each treatment had thirty replicates. Parameters such as hatchability, hatch weight and post hatch performance were studied. Results: In ovo feeding of nano minerals were not harmful to the developing embryo and did not influence the hatchability. Significantly (p<0.05) best feed efficiency for nano forms of zinc (2.16), copper (2.46) and selenium (2.51) were observed, when 40, 4 and 0.225 µg/egg respectively were in ovo supplemented. Except in nano form of copper at 12 µg per egg which had significantly (p<0.05) highest breast muscle percentage there was no distinct trend to indicate that dressing percentage or breast muscle yield was influenced in other treatments. Conclusion: Nano forms of zinc, copper and selenium can be prepared at laboratory conditions. In ovo feeding of nano forms of zinc, copper and selenium at 18th day of incubation through amniotic route does not harm the developing embryo, does not affect hatchability. PMID:27057113

Concentrations and bioaccessibility of metals in vegetation and dust near a mining haul road, Cape Krusenstern National Monument, Alaska

USGS Publications Warehouse

Brumbaugh, W.G.; Morman, S.A.; May, T.W.

2011-01-01

Vegetation, sub-surface peat, and road dust were sampled near the Delong Mountain Transportation System (DMTS) haul road in northwest Alaska in 2005-2006 to document aluminum, barium, cadmium, lead, and zinc concentrations, and to evaluate bioaccessibility of these metals. The DMTS haul road is the transport corridor between Red Dog Mine (a large-scale, lead-zinc mine and mill) and the coastal shipping port, and it traverses National Park Service lands. Compared to reference locations, total metal concentrations in four types of vegetation (birch, cranberry, and willow leaves, and cotton grass blades/stalks) collected 25 m from the haul road were enriched on average by factors of 3.5 for zinc, 8.0 for barium, 20 for cadmium, and 150 for lead. Triple rinsing of vegetation with a water/methanol mixture reduced metals concentrations by at most 50%, and cadmium and zinc concentrations were least affected by rinsing. Cadmium and zinc bioaccessibility was greater in vegetation (50% to 100%) than in dust (15% to 20%); whereas the opposite pattern was observed for lead bioaccessibility (<30% in vegetation; 50% in dust). Barium exhibited low-to-intermediate bioaccessibility in dust and vegetation (20% to 40%), whereas aluminum bioaccessibility was relatively low (<6%) in all sample types. Our reconnaissance-level study indicates that clean-up and improvements in lead/zinc concentrate transfer activities have been effective; however, as of 2006, metal dispersion from past and/or present releases of fugitive dusts along the DMTS road still may have been contributing to elevated metals in surface vegetation. Vegetation was most enriched in lead, but because bioaccessibility of cadmium was greater, any potential risks to animals that forage near the haul road might be equally important for both of these metals. ?? 2011 Springer Science+Business Media B.V. (outside the USA).

Lipid peroxidation and antioxidant status in workers exposed to PCDD/Fs of metal recovery plants.

PubMed

Chen, Hsiu-Ling; Hsu, Ching-Yi; Hung, Dong-Zong; Hu, Miao-Lin

2006-12-15

Secondary copper smelters, which primarily utilize the waste materials that contain organic impurities, and the zinc recovery plant, which handles mostly fly ash and slag from the iron and steel industry, are major emission sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in Taiwan. In this study, we compared the levels of erythrocyte glutathione (GSH), erythrocyte superoxide dismutase (SOD) and plasma malondialdehyde (MDA) in workers at a secondary copper smelting plant and a zinc recovery plant who may have been exposed to PCDD/Fs. Though the PCDD/F levels were higher in workers of zinc recovery plant than those of secondary copper smelting plant, no significant difference was found for serum PCDD/F levels between the two kinds of plants. We observed a significant difference in plasma MDA levels between workers at the zinc recovery plant (2.54 microM) and those at the copper smelting plant (1.79 microM). There was and a significant positive correlation between plasma MDA levels and the PCDD/Fs levels. In addition, we observed that the MDA levels were not affected by smoking and exercise status. Therefore, the data suggest that the MDA levels of the metal recovery workers are influenced by their PCDD/F exposure. The erythrocyte SOD activity in workers from the zinc recovery plant was marginally higher than that from the secondary copper plant (196 vs. 146 units/ml, p<0.06). In both plants, large variations in the MDA and SOD levels were found, especially in the high-PCDD/Fs-exposure group, which may be attributed, at least partially, to the differences in smoking status and the number of cigarettes smoked. Overall, our results indicate a higher oxidative stress in workers of the zinc recovery plant than in workers of the secondary copper smelting plant in Taiwan.

In vitro effects of dental cements on hard and soft tissues associated with dental implants.

PubMed

Rodriguez, Lucas C; Saba, Juliana N; Chung, Kwok-Hung; Wadhwani, Chandur; Rodrigues, Danieli C

2017-07-01

Dental cements for cement-retained restorations are often chosen based on clinician preference for the product's material properties, mixing process, delivery mechanism, or viscosity. The composition of dental cement may play a significant role in the proliferation or inhibition of different bacterial strains associated with peri-implant disease, and the effect of dental cements on host cellular proliferation may provide further insight into appropriate cement material selection. The purpose of this in vitro study was to investigate the cellular host response of bone cells (osteoblasts) and soft tissue cells (gingival fibroblasts) to dental cements. Zinc oxide (eugenol and noneugenol), zinc phosphate, and acrylic resin cements were molded into pellets and directly applied to confluent preosteoblast (cell line MC3T3 E1) or gingival fibroblast cell cultures (cell line HGF) to determine cellular viability after exposure. Controls were defined as confluent cell cultures with no cement exposure. Direct contact cell culture testing was conducted following International Organization for Standardization 10993 methods, and all experiments were performed in triplicate. To compare either the MC3T3 E1 cell line, or the HGF cell line alone, a 1-way ANOVA test with multiple comparisons was used (α=.05). To compare the MC3T3 E1 cell line results and the HGF cell line results, a 2-way ANOVA test with multiple comparisons was used (α=.05). The results of this study illustrated that while both bone and soft tissue cell lines were vulnerable to the dental cement test materials, the soft tissue cell line (human gingival fibroblasts) was more susceptible to reduced cellular viability after exposure. The HGF cell line was much more sensitive to cement exposure. Here, the acrylic resin, zinc oxide (eugenol), and zinc phosphate cements significantly reduced cellular viability after exposure with respect to HGF cells only. Within the limitation of this in vitro cellular study, the results indicated that cell response to various implant cements varied significantly, with osteoblast proliferation much less affected than gingival fibroblast cells. Furthermore, the zinc oxide noneugenol dental cement appeared to affect the cell lines significantly less than the other test cements. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Synthesis, characterization and application of two-dimensional layered metal hydroxides for environmental remediation purposes

NASA Astrophysics Data System (ADS)

Machingauta, Cleopas

Two-dimensional layered nano composites, which include layered double hydroxides (LDHs), hydroxy double salts (HDSs) and layered hydroxide salts (LHSs) are able to intercalate different molecular species within their gallery space. These materials have a tunable structural composition which has made them applicable as fire retardants, adsorbents, catalysts, catalyst support materials, and ion exchangers. Thermal treatment of these materials results in destruction of the layers and formation of mixed metal oxides (MMOs) and spinels. MMOs have the ability to adsorb anions from solution and may also regenerate layered structures through a phenomenon known as memory effect. Zinc-nickel hydroxy nitrate was used for the uptake of a series of halogenated acetates (HAs). HAs are pollutants introduced into water systems as by-products of water chlorination and pesticide degradation; their sequestration from water is thus crucial. Optimization of layered materials for controlled uptake requires an understanding of their ion-exchange kinetics and thermodynamics. Exchange kinetics of these anions was monitored using ex-situ PXRD, UV-vis, HPLC and FTIR. It was revealed that exchange rates and uptake efficiencies are related to electronic spatial extents and the charge on carboxyl-oxygen atoms. In addition, acetate and nitrate-based HDSs were used to explore how altering the hydroxide layer affects uptake of acetate/nitrate ions. Changing the metal identities affects the interaction of the anions with the layers. From FTIR, we observed that nitrates coordinate in a D3h and Cs/C 2v symmetry; the nitrates in D3h symmetry were easily exchangeable. Interlayer hydrogen bonding was also revealed to be dependent on metal identity. Substituting divalent cations with trivalent cations produces materials with a higher charge density than HDSs and LHSs. A comparison of the uptake efficiency of zinc-aluminum, zinc-gallium and zinc-nickel hydroxy nitrates was performed using trichloroacetic acid as target anion. Uptake efficiency was better for LDHs than HDS, and between the LDHs, zinc-aluminum hydroxy nitrate was the best material for the uptake of tClAc. Calcined LDHs were applied for the uptake of methyl-orange, model azo-dye. The ability to regenerate the layered structures was helpful for improving adsorption efficiency. It has been reveal that calcined LDHs are also better adsorbents than calcined HDSs.

Chondroprotective effect of zinc oxide nanoparticles in conjunction with hypoxia on bovine cartilage-matrix synthesis.

PubMed

Mirza, Eraj Humayun; Pan-Pan, Chong; Wan Ibrahim, Wan Mohd Azhar Bin; Djordjevic, Ivan; Pingguan-Murphy, Belinda

2015-11-01

Articular cartilage is a tissue specifically adapted to a specific niche with a low oxygen tension (hypoxia), and the presence of such conditions is a key factor in regulating growth and survival of chondrocytes. Zinc deficiency has been linked to cartilage-related disease, and presence of Zinc is known to provide antibacterial benefits, which makes its inclusion attractive in an in vitro system to reduce infection. Inclusion of 1% zinc oxide nanoparticles (ZnONP) in poly octanediol citrate (POC) polymer cultured in hypoxia has not been well determined. In this study we investigated the effects of ZnONP on chondrocyte proliferation and matrix synthesis cultured under normoxia (21% O2 ) and hypoxia (5% O2 ). We report an upregulation of chondrocyte proliferation and sulfated glycosaminoglycan (S-GAG) in hypoxic culture. Results demonstrate a synergistic effect of oxygen concentration and 1% ZnONP in up-regulation of anabolic gene expression (Type II collagen and aggrecan), and a down regulation of catabolic (MMP-13) gene expression. Furthermore, production of transcription factor hypoxia-inducible factor 1A (HIF-1A) in response to hypoxic condition to regulate chondrocyte survival under hypoxia is not affected by the presence of 1% ZnONP. Presence of 1% ZnONP appears to act to preserve homeostasis of cartilage in its hypoxic environment. © 2015 Wiley Periodicals, Inc.

A novel zinc finger protein 219-like (ZNF219L) is involved in the regulation of collagen type 2 alpha 1a (col2a1a) gene expression in zebrafish notochord.

PubMed

Lien, Huang-Wei; Yang, Chung-Hsiang; Cheng, Chia-Hsiung; Hung, Chin-Chun; Liao, Wei-Hao; Hwang, Pung-Pung; Han, Yu-San; Huang, Chang-Jen

2013-01-01

The notochord is required for body plan patterning in vertebrates, and defects in notochord development during embryogenesis can lead to diseases affecting the adult. It is therefore important to elucidate the gene regulatory mechanism underlying notochord formation. In this study, we cloned the zebrafish zinc finger 219-like (ZNF219L) based on mammalian ZNF219, which contains nine C2H2-type zinc finger domains. Through whole-mount in situ hybridization, we found that znf219L mRNA is mainly expressed in the zebrafish midbrain-hindbrain boundary, hindbrain, and notochord during development. The znf219L morpholino knockdown caused partial abnormal notochord phenotype and reduced expression of endogenous col2a1a in the notochord specifically. In addition, ZNF219L could recognize binding sites with GGGGG motifs and trigger augmented activity of the col2a1a promoter in a luciferase assay. Furthermore, in vitro binding experiments revealed that ZNF219L recognizes the GGGGG motifs in the promoter region of the zebrafish col2a1a gene through its sixth and ninth zinc finger domains. Taken together, our results reveal that ZNF219L is involved in regulating the expression of col2a1a in zebrafish notochord specifically.

A Novel Zinc Finger Protein 219-like (ZNF219L) is Involved in the Regulation of Collagen Type 2 Alpha 1a (col2a1a) Gene Expression in Zebrafish Notochord

PubMed Central

Lien, Huang-Wei; Yang, Chung-Hsiang; Cheng, Chia-Hsiung; Hung, Chin-Chun; Liao, Wei-Hao; Hwang, Pung-Pung; Han, Yu-San; Huang, Chang-Jen

2013-01-01

The notochord is required for body plan patterning in vertebrates, and defects in notochord development during embryogenesis can lead to diseases affecting the adult. It is therefore important to elucidate the gene regulatory mechanism underlying notochord formation. In this study, we cloned the zebrafish zinc finger 219-like (ZNF219L) based on mammalian ZNF219, which contains nine C2H2-type zinc finger domains. Through whole-mount in situ hybridization, we found that znf219L mRNA is mainly expressed in the zebrafish midbrain-hindbrain boundary, hindbrain, and notochord during development. The znf219L morpholino knockdown caused partial abnormal notochord phenotype and reduced expression of endogenous col2a1a in the notochord specifically. In addition, ZNF219L could recognize binding sites with GGGGG motifs and trigger augmented activity of the col2a1a promoter in a luciferase assay. Furthermore, in vitro binding experiments revealed that ZNF219L recognizes the GGGGG motifs in the promoter region of the zebrafish col2a1a gene through its sixth and ninth zinc finger domains. Taken together, our results reveal that ZNF219L is involved in regulating the expression of col2a1a in zebrafish notochord specifically. PMID:24155663

Ionophore and Biometal Modulation of P-glycoprotein Expression and Function in Human Brain Microvascular Endothelial Cells.

PubMed

McInerney, Mitchell P; Volitakis, Irene; Bush, Ashley I; Banks, William A; Short, Jennifer L; Nicolazzo, Joseph A

2018-03-05

Biometals such as zinc and copper have been shown to affect tight junction expression and subsequently blood-brain barrier (BBB) integrity. Whether these biometals also influence the expression and function of BBB transporters such as P-glycoprotein (P-gp) however is currently unknown. Using the immortalised human cerebral microvascular endothelial (hCMEC/D3) cell line, an in-cell western assay (alongside western blotting) assessed relative P-gp expression after treatment with the metal ionophore clioquinol and biometals zinc and copper. The fluorescent P-gp substrate rhodamine-123 was employed to observe functional modulation, and inductively coupled plasma mass spectrometry (ICP-MS) provided information on biometal trafficking. A 24-h treatment with clioquinol, zinc and copper (0.5, 0.5 and 0.1 μM) induced a significant upregulation of P-gp (1.7-fold) assessed by in-cell western and this was confirmed with western blotting (1.8-fold increase). This same treatment resulted in a 23% decrease in rhodamine-123 accumulation over a 1 h incubation. ICP-MS demonstrated that while t8his combination treatment had no effect on intracellular zinc concentrations, the treatment significantly enhanced bioavailable copper (4.6-fold). Enhanced delivery of copper to human brain microvascular endothelial cells is associated with enhanced expression and function of the important efflux pump P-gp, which may provide therapeutic opportunities for P-gp modulation.

Biosorption of lead, cadmium, and zinc by Citrobacter strain MCM B-181: Characterization studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puranik, P.R.; Paknikar, K.M.

1999-03-01

The biosorption process for removal of lead, cadmium, and zinc by Citrobacter strain MCM B-181, a laboratory isolate, was characterized. Effects of environmental factors and growth conditions on metal uptake capacity were studied. Pretreatment of biomass with chemical agents increased cadmium sorption efficiency; however, there was no significant enhancement in lead and zinc sorption capacity. Metal sorption by Citrobacter strain MCM B-181 was found to be influenced by the pH of the solution, initial metal concentration, biomass concentration, and type of growth medium. The metal sorption process was not affected by the age of the culture or change in temperature.more » Equilibrium metal sorption was found to fit the Langmuir adsorption model. Kinetic studies showed that metal uptake by Citrobacter strain MCm B-181 was a fast process, requiring < 20 min to achieve > 90% adsorption efficiency. The presence of cations reduced lead, zinc, and cadmium sorption to the extent of 11.8%, 84.3%, and 33.4%, respectively. When biomass was exposed to multimetal solutions, metals were adsorbed in the order Co{sup 2+} < Ni{sup 2+} < Cd{sup 2+} < Cu{sup 2+}, Zn{sup 2+} < Pb{sup 2+}. A new mathematical model used for batch kinetic studies was found to be highly useful in prediction of experimentally obtained metal concentration profiles as a function of time.« less

A reconnaissance for signs of a Mississippi Valley-type lead-zinc mineralizing system on the eastern flank of the Rutbah Uplift, Anbar Province, Iraq

USGS Publications Warehouse

Hayes, Timothy S.; Mustafa, Mazin; Bennet, Thair

2014-01-01

Reconnaissance field visits and rock sampling were conducted at eight geologically selected locations within Mesozoic rocks on the eastern flank of the Rutbah Uplift, Anbar Province, western Iraq, in an attempt to determine if these rocks have been affected by a Mississippi Valley-Type (MVT) lead-zinc mineralizing system. Samples subsequently were studied by carbonate mineral staining, transmitted and reflected light petrology, and scanning electron microscopy with semi-quantitative energy dispersive elemental analyses. Single samples were studied by each, inductively coupled plasma mass spectrometry analyses of trace elements and fluid inclusion microthermometry. Permissive evidence indicates that there has been a MVT system present, but none of the evidence is considered definitive.

Photoswitching in azobenzene self-assembled monolayers capped on zinc oxide: nanodots vs nanorods.

PubMed

Shah, Syed Mujtaba; Martini, Cyril; Ackermann, Jörg; Fages, Frédéric

2012-02-01

We report the synthesis and spectroscopic characterization of nanohybrid structures consisting of an azobenzene compound grafted on the surface of zinc oxide nanoparticles. Characteristic bathochromic shifts indicate that the azobenzene photochromic molecules self-assemble onto the surface of the nanocrystals. The extent of packing is dependent on the shape of the nanoparticle. ZnO nanorods, with flat facets, enable a tighter organization of the molecules in the self-assembled monolayer than in the case of nanodots that display a more curvated shape. Consistently, the efficiency of photochromic switching of the self-assembled monolayer on ZnO nanoparticles is also shown to be strongly affected by nanoparticle shape. Copyright © 2011 Elsevier Inc. All rights reserved.

Reduction of channel resistance in amorphous oxide thin-film transistors with buried layer

NASA Astrophysics Data System (ADS)

Chong, Eugene; Kim, Bosul; Lee, Sang Yeol

2012-04-01

A silicon-indium-zinc-oxide (SIZO) thin film transistor (TFT) with low channel-resistance (RCH) indium-zinc-oxide (In2O3:ZnO = 9:1) buried layer annealed at low temperature of 200°C exhibited high field-effect mobility (μFE) over 55.8 cm2/V·s which is 5 times higher than that of the conventional TFTs due to small threshold voltage (Vth) change of 1.8 V under bias-temperature stress (BTS) condition for 420 minutes. The low-RCH buried-layer allows more strong current-path formed in channel layer well within relatively high-RCH channel-layer since it is less affected by the channel bulk and/or back interface trap with high carrier concentration.

Synthesis, characterization, and application of a Zn (II)-imprinted polymer grafted on graphene oxide/magnetic chitosan nanocomposite for selective extraction of zinc ions from different food samples.

PubMed

Kazemi, Elahe; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Ranjbar, Mansoureh

2017-12-15

A novel Zn(II) imprinted polymer was synthesized via a co-precipitation method using graphene oxide/magnetic chitosan nanocomposite as supporting material. The synthesized imprinted polymer was characterized by Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) and applied as a sorbent for selective magnetic solid phase extraction of zinc followed by its determination by flame atomic absorption spectrometry. The kinetic and isothermal adsorption experiments were carried out and all parameters affecting the extraction process was optimized. Under the optimal experimental conditions, the developed procedure exhibits a linear dynamic range of 0.5-5.0µgL -1 with a detection limit of 0.09µgL -1 and quantification limit of 0.3µgL -1 . The maximum sorption capacity of the sorbent was found to be 71.4mgg -1 . The developed procedure was successfully applied to the selective extraction and determination of zinc in various samples including well water, drinking water, black tea, rice, and milk. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of zinc oxide on the electronic properties of carbonated hydroxyapatite

NASA Astrophysics Data System (ADS)

Refaat, Ahmed; Youness, Rasha A.; Taha, Mohammed A.; Ibrahim, Medhat

2017-11-01

Zinc oxide (ZnO)-doped carbonate substituted hydroxyapatite (CHA) was successfully prepared with different ZnO contents up to 3 wt% and then samples were subjected to study with Fourier transform infrared (FTIR) spectroscopy. FTIR indicated that the interaction is physical and consequently molecular modeling was consulted to understand the effect of ZnO upon CHA. A model molecule of Ca10(PO4)6(OH)2·14H2O was built then interacted with Zn with different schemes through 4 active sites namely O of (PO4); O of OH; Ca of Ca(OH)2 and P of (PO4). For each interaction, two possibilities were tried; one through oxygen and the other through zinc of ZnO. The interaction of ZnO with CHA resulted in changes in the physical properties such as the final heat of formation, ionization potential, and even molecular dimensions. This may be due to the change in the electronic distribution which in turn changes the total dipole moment and hence the reactivity that could also affect the physical properties.

Acute changes in cellular zinc alters zinc uptake rates prior to zinc transporter gene expression in Jurkat cells.

PubMed

Holland, Tai C; Killilea, David W; Shenvi, Swapna V; King, Janet C

2015-12-01

A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells.

Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

PubMed Central

Donangelo, Carmen Marino; King, Janet C.

2012-01-01

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide. PMID:22852063

Biomarkers of Nutrition for Development (BOND)—Zinc Review12345

PubMed Central

King, Janet C; Brown, Kenneth H; Gibson, Rosalind S; Krebs, Nancy F; Lowe, Nicola M; Siekmann, Jonathan H; Raiten, Daniel J

2016-01-01

Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. Cellular, tissue, and whole-body zinc homeostasis is tightly controlled to sustain metabolic functions over a wide range of zinc intakes, making it difficult to assess zinc insufficiency or excess. The BOND (Biomarkers of Nutrition for Development) Zinc Expert Panel recommends 3 measurements for estimating zinc status: dietary zinc intake, plasma zinc concentration (PZC), and height-for-age of growing infants and children. The amount of dietary zinc potentially available for absorption, which requires an estimate of dietary zinc and phytate, can be used to identify individuals and populations at risk of zinc deficiency. PZCs respond to severe dietary zinc restriction and to zinc supplementation; they also change with shifts in whole-body zinc balance and clinical signs of zinc deficiency. PZC cutoffs are available to identify individuals and populations at risk of zinc deficiency. However, there are limitations in using the PZC to assess zinc status. PZCs respond less to additional zinc provided in food than to a supplement administered between meals, there is considerable interindividual variability in PZCs with changes in dietary zinc, and PZCs are influenced by recent meal consumption, the time of day, inflammation, and certain drugs and hormones. Insufficient data are available on hair, urinary, nail, and blood cell zinc responses to changes in dietary zinc to recommend these biomarkers for assessing zinc status. Of the potential functional indicators of zinc, growth is the only one that is recommended. Because pharmacologic zinc doses are unlikely to enhance growth, a growth response to supplemental zinc is interpreted as indicating pre-existing zinc deficiency. Other functional indicators reviewed but not recommended for assessing zinc nutrition in clinical or field settings because of insufficient information are the activity or amounts of zinc-dependent enzymes and proteins and biomarkers of oxidative stress, inflammation, or DNA damage. PMID:26962190

Modulation of intestinal gene expression by dietary zinc status: Effectiveness of cDNA arrays for expression profiling of a single nutrient deficiency

PubMed Central

Blanchard, Raymond K.; Moore, J. Bernadette; Green, Calvert L.; Cousins, Robert J.

2001-01-01

Mammalian nutritional status affects the homeostatic balance of multiple physiological processes and their associated gene expression. Although DNA array analysis can monitor large numbers of genes, there are no reports of expression profiling of a micronutrient deficiency in an intact animal system. In this report, we have tested the feasibility of using cDNA arrays to compare the global changes in expression of genes of known function that occur in the early stages of rodent zinc deficiency. The gene-modulating effects of this deficiency were demonstrated by real-time quantitative PCR measurements of altered mRNA levels for metallothionein 1, zinc transporter 2, and uroguanylin, all of which have been previously documented as zinc-regulated genes. As a result of the low level of inherent noise within this model system and application of a recently reported statistical tool for statistical analysis of microarrays [Tusher, V.G., Tibshirani, R. & Chu, G. (2001) Proc. Natl. Acad. Sci. USA 98, 5116–5121], we demonstrate the ability to reproducibly identify the modest changes in mRNA abundance produced by this single micronutrient deficiency. Among the genes identified by this array profile are intestinal genes that influence signaling pathways, growth, transcription, redox, and energy utilization. Additionally, the influence of dietary zinc supply on the expression of some of these genes was confirmed by real-time quantitative PCR. Overall, these data support the effectiveness of cDNA array expression profiling to investigate the pleiotropic effects of specific nutrients and may provide an approach to establishing markers for assessment of nutritional status. PMID:11717422

Stability of Vitamin A, Iron and Zinc in Fortified Rice during Storage and Its Impact on Future National Standards and Programs—Case Study in Cambodia

PubMed Central

Kuong, Khov; Laillou, Arnaud; Chea, Chantum; Chamnan, Chhoun; Berger, Jacques; Wieringa, Frank T.

2016-01-01

Fortified rice holds great potential for bringing essential micronutrients to a large part of the world population. The present study quantified the losses of three different micronutrients (vitamin A, iron, zinc) in fortified rice that were produced using three different techniques (hot extrusion, cold extrusion, and coating) and stored at two different environments (25 ± 5 °C at a humidity of 60% and 40 ± 5 °C at a humidity of 75%) for up to one year. Fortified rice premix from the different techniques was mixed with normal rice in a 1:100 ratio. Each sample was analyzed in triplicate. The study confirmed the high stability of iron and zinc during storage while the retention of vitamin A was significantly affected by storage and the type of techniques used to make rice premix. Losses for iron and zinc were typically <10% for any type of rice premix. After 12 months at mild conditions (25 °C and humidity of 60%), losses for vitamin A ranged from 20% for cold extrusion, 30% for hot extruded rice 77% for coated rice premix. At higher temperatures and humidity, losses of vitamin A were 40%–50% for extruded premix and 93% for coated premix after 6 months. We conclude that storage does lead to a major loss of vitamin A and question whether rice is a suitable food vehicle to fortify with vitamin A. For Cambodia, fortification of rice with iron and zinc could be an effective strategy to improve the micronutrient status of the population if no other food vehicles are available. PMID:26784227

Controlling corrosion rate of Magnesium alloy using powder mixed electrical discharge machining

NASA Astrophysics Data System (ADS)

Razak, M. A.; Rani, A. M. A.; Saad, N. M.; Littlefair, G.; Aliyu, A. A.

2018-04-01

Biomedical implant can be divided into permanent and temporary employment. The duration of a temporary implant applied to children and adult is different due to different bone healing rate among the children and adult. Magnesium and its alloys are compatible for the biodegradable implanting application. Nevertheless, it is difficult to control the degradation rate of magnesium alloy to suit the application on both the children and adult. Powder mixed electrical discharge machining (PM-EDM) method, a modified EDM process, has high capability to improve the EDM process efficiency and machined surface quality. The objective of this paper is to establish a formula to control the degradation rate of magnesium alloy using the PM-EDM method. The different corrosion rate of machined surface is hypothesized to be obtained by having different combinations of PM-EDM operation inputs. PM-EDM experiments are conducted using an opened-loop PM-EDM system and the in-vitro corrosion tests are carried out on the machined surface of each specimen. There are four operation inputs investigated in this study which are zinc powder concentration, peak current, pulse on-time and pulse off-time. The results indicate that zinc powder concentration is significantly affecting the response with 2 g/l of zinc powder concentration obtaining the lowest corrosion rate. The high localized temperature at the cutting zone in spark erosion process causes some of the zinc particles get deposited on the machined surface, hence improving the surface characteristics. The suspended zinc particles in the dielectric fluid have also improve the sparking efficiency and the uniformity of sparks distribution. From the statistical analysis, a formula was developed to control the corrosion rate of magnesium alloy within the range from 0.000183 mm/year to 0.001528 mm/year.

Mutations in the Putative Zinc-Binding Motif of UL52 Demonstrate a Complex Interdependence between the UL5 and UL52 Subunits of the Human Herpes Simplex Virus Type 1 Helicase/Primase Complex

PubMed Central

Chen, Yan; Carrington-Lawrence, Stacy D.; Bai, Ping; Weller, Sandra K.

2005-01-01

Herpes simplex virus type 1 (HSV-1) encodes a heterotrimeric helicase-primase (UL5/8/52) complex. UL5 contains seven motifs found in helicase superfamily 1, and UL52 contains conserved motifs found in primases. The contributions of each subunit to the biochemical activities of the complex, however, remain unclear. We have previously demonstrated that a mutation in the putative zinc finger at UL52 C terminus abrogates not only primase but also ATPase, helicase, and DNA-binding activities of a UL5/UL52 subcomplex, indicating a complex interdependence between the two subunits. To test this hypothesis and to further investigate the role of the zinc finger in the enzymatic activities of the helicase-primase, a series of mutations were constructed in this motif. They differed in their ability to complement a UL52 null virus: totally defective, partial complementation, and potentiating. In this study, four of these mutants were studied biochemically after expression and purification from insect cells infected with recombinant baculoviruses. All mutants show greatly reduced primase activity. Complementation-defective mutants exhibited severe defects in ATPase, helicase, and DNA-binding activities. Partially complementing mutants displayed intermediate levels of these activities, except that one showed a wild-type level of helicase activity. These data suggest that the UL52 zinc finger motif plays an important role in the activities of the helicase-primase complex. The observation that mutations in UL52 affected helicase, ATPase, and DNA-binding activities indicates that UL52 binding to DNA via the zinc finger may be necessary for loading UL5. Alternatively, UL5 and UL52 may share a DNA-binding interface. PMID:15994803

Mutations in the putative zinc-binding motif of UL52 demonstrate a complex interdependence between the UL5 and UL52 subunits of the human herpes simplex virus type 1 helicase/primase complex.

PubMed

Chen, Yan; Carrington-Lawrence, Stacy D; Bai, Ping; Weller, Sandra K

2005-07-01

Herpes simplex virus type 1 (HSV-1) encodes a heterotrimeric helicase-primase (UL5/8/52) complex. UL5 contains seven motifs found in helicase superfamily 1, and UL52 contains conserved motifs found in primases. The contributions of each subunit to the biochemical activities of the complex, however, remain unclear. We have previously demonstrated that a mutation in the putative zinc finger at UL52 C terminus abrogates not only primase but also ATPase, helicase, and DNA-binding activities of a UL5/UL52 subcomplex, indicating a complex interdependence between the two subunits. To test this hypothesis and to further investigate the role of the zinc finger in the enzymatic activities of the helicase-primase, a series of mutations were constructed in this motif. They differed in their ability to complement a UL52 null virus: totally defective, partial complementation, and potentiating. In this study, four of these mutants were studied biochemically after expression and purification from insect cells infected with recombinant baculoviruses. All mutants show greatly reduced primase activity. Complementation-defective mutants exhibited severe defects in ATPase, helicase, and DNA-binding activities. Partially complementing mutants displayed intermediate levels of these activities, except that one showed a wild-type level of helicase activity. These data suggest that the UL52 zinc finger motif plays an important role in the activities of the helicase-primase complex. The observation that mutations in UL52 affected helicase, ATPase, and DNA-binding activities indicates that UL52 binding to DNA via the zinc finger may be necessary for loading UL5. Alternatively, UL5 and UL52 may share a DNA-binding interface.

Comparison of methods to assess adherence to small-quantity lipid-based nutrient supplements (SQ-LNS) and dispersible tablets among young Burkinabé children participating in a community-based intervention trial.

PubMed

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

2015-12-01

Adherence to supplementation provided during an intervention trial can affect interpretation of study outcomes. We compared different approaches for estimating adherence to small-quantity lipid-based nutrient supplements (SQ-LNS) and dispersible tablets in a randomised clinical trial in Burkina Faso. A total of 2435 children (9-18 months) were randomly assigned to receive daily 20 g SQ-LNS with varying contents of zinc and a dispersible tablet containing 0 or 5 mg zinc. Adherence to SQ-LNS and tablets was assessed for all children through weekly caregiver interviews, and disappearance rate was calculated based on empty and unused packages returned during home visits. Additional adherence data were collected in different randomly selected subgroups of children: 12-h home observations were completed for children 11 and 16 months of age (n = 192) to assess consumption of SQ-LNS and dispersible tablets, and plasma zinc concentration was measured at baseline and 18 months (n = 310). Apparent adherence to SQ-LNS and dispersible tablets differed according to the assessment method used. Average daily caregiver-reported adherence to both SQ-LNS and dispersible tablets was 97 ± 6%. Disappearance rates showed similarly high average weekly adherence (98 ± 4%). In contrast, only 63% and 54% of children at 11 and 16 months, respectively, received SQ-LNS during the 12-h home observation periods, and fewer (32% and 27%) received a tablet. The lack of change in plasma zinc concentration after 9 months of supplementation suggests low adherence to the zinc tablet. Better methods are needed to assess adherence in community-based supplementation trials. © 2014 John Wiley & Sons Ltd.

Mercury exposure, nutritional deficiencies and metabolic disruptions may affect learning in children

PubMed Central

Dufault, Renee; Schnoll, Roseanne; Lukiw, Walter J; LeBlanc, Blaise; Cornett, Charles; Patrick, Lyn; Wallinga, David; Gilbert, Steven G; Crider, Raquel

2009-01-01

Among dietary factors, learning and behavior are influenced not only by nutrients, but also by exposure to toxic food contaminants such as mercury that can disrupt metabolic processes and alter neuronal plasticity. Neurons lacking in plasticity are a factor in neurodevelopmental disorders such as autism and mental retardation. Essential nutrients help maintain normal neuronal plasticity. Nutritional deficiencies, including deficiencies in the long chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, the amino acid methionine, and the trace minerals zinc and selenium, have been shown to influence neuronal function and produce defects in neuronal plasticity, as well as impact behavior in children with attention deficit hyperactivity disorder. Nutritional deficiencies and mercury exposure have been shown to alter neuronal function and increase oxidative stress among children with autism. These dietary factors may be directly related to the development of behavior disorders and learning disabilities. Mercury, either individually or in concert with other factors, may be harmful if ingested in above average amounts or by sensitive individuals. High fructose corn syrup has been shown to contain trace amounts of mercury as a result of some manufacturing processes, and its consumption can also lead to zinc loss. Consumption of certain artificial food color additives has also been shown to lead to zinc deficiency. Dietary zinc is essential for maintaining the metabolic processes required for mercury elimination. Since high fructose corn syrup and artificial food color additives are common ingredients in many foodstuffs, their consumption should be considered in those individuals with nutritional deficits such as zinc deficiency or who are allergic or sensitive to the effects of mercury or unable to effectively metabolize and eliminate it from the body. PMID:19860886

Soil Chemistry Still Affected 23 Years After Large Application of Fluidized Bed Material

USDA-ARS?s Scientific Manuscript database

This study was conducted to assess the movement of arsenic, aluminum, calcium, copper, iron, lead, magnesium, manganese, mercury and zinc in an old apple (Malus domestica Borkh) orchard that received a one time application of 36 kg/ m2 of fluidized bed combustion material (FBCM) 23 years earlier. S...

Trace element status and zinc homeostasis differ in breast and formula-fed piglets

USDA-ARS?s Scientific Manuscript database

Differences in trace element composition and bioavailability between breast milk and infant formulas may affect metal homeostasis in neonates. In the current study, piglets were fed soy infant formula (Soy), cow's milk formula (Milk), or were allowed to suckle from the sow from PND2 to PND21. Serum ...

Effects of aging and walnut diet on DNA methylation and expression of immediate-early genes in critical brain regions

USDA-ARS?s Scientific Manuscript database

Emerging evidence indicates a direct link between age-associated changes in epigenetic mechanisms and onset of neurodegenerative diseases, and that these genomic modulations are directly affected by the diet. Diets deficient in folate, choline and methionine, or the trace elements zinc and selenium,...

Identification of QTL affecting seed mineral concentrations and content in the model legume Medicago truncatula

USDA-ARS?s Scientific Manuscript database

Increasing the amount of bioavailable micronutrients such as iron and zinc in plant foods for human consumption is a challenge, especially in developing countries where plant foods comprise a significant portion of the diet. Legume seeds have the potential to provide the essential nutrients require...

Identification of quantitative trait loci (QTL) affecting seed mineral content in the model legume Medicago truncatula

USDA-ARS?s Scientific Manuscript database

Increasing the amount of bioavailable micronutrients such as iron and zinc in plant foods for human consumption is a challenge especially in developing countries where plant foods comprise a significant portion of the diet. Legume seeds have the potential to provide the essential nutrients required...

Ionomic characterization of maize kernels in the Intermated B73 x Mo17 (IBM) population

USDA-ARS?s Scientific Manuscript database

Dietary mineral deficiencies affect nearly half of the people on our planet, largely due to poverty. Many people do not receive adequate calcium, iron, zinc, and other mineral nutrients from the food they grow or purchase. These kinds of dietary deficiencies create both acute and chronic health prob...

Calcium and zinc differentially affect the structure of lipid membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kučerka, Norbert; Dushanov, Ermuhammad; Kholmurodov, Kholmirzo T.

Interactions of calcium (Ca 2+) and zinc (Zn 2+) cations with biomimetic membranes made of dipalmitoylphosphatidylcholine (DPPC) were studied by small angle neutron diffraction (SAND). Experiments show that the structure of these lipid bilayers is differentially affected by the two divalent cations. Initially, both Ca 2+ and Zn 2+ cause DPPC bilayers to thicken, while further increases in Ca 2+ concentration result in the bilayer thinning, eventually reverting to having the same thickness as pure DPPC. The binding of Zn 2+, on the other hand, causes the bilayers to swell to a maximum thickness, and the addition of more Znmore » 2+ does not result in a further thickening of the membrane. Agreement between our results obtained using oriented planar membranes and those from vesicular samples implies that the effect of cations on bilayer thickness is the result of electrostatic interactions, rather than geometrical constraints due to bilayer curvature. This notion is further reinforced by MD simulations. Lastly, the radial distribution functions reveal a strong interaction between Ca 2+ and the phosphate oxygens, while Zn 2+ shows a much weaker binding specificity.« less

Calcium and zinc differentially affect the structure of lipid membranes

DOE PAGES

Kučerka, Norbert; Dushanov, Ermuhammad; Kholmurodov, Kholmirzo T.; ...

2017-03-09

Interactions of calcium (Ca 2+) and zinc (Zn 2+) cations with biomimetic membranes made of dipalmitoylphosphatidylcholine (DPPC) were studied by small angle neutron diffraction (SAND). Experiments show that the structure of these lipid bilayers is differentially affected by the two divalent cations. Initially, both Ca 2+ and Zn 2+ cause DPPC bilayers to thicken, while further increases in Ca 2+ concentration result in the bilayer thinning, eventually reverting to having the same thickness as pure DPPC. The binding of Zn 2+, on the other hand, causes the bilayers to swell to a maximum thickness, and the addition of more Znmore » 2+ does not result in a further thickening of the membrane. Agreement between our results obtained using oriented planar membranes and those from vesicular samples implies that the effect of cations on bilayer thickness is the result of electrostatic interactions, rather than geometrical constraints due to bilayer curvature. This notion is further reinforced by MD simulations. Lastly, the radial distribution functions reveal a strong interaction between Ca 2+ and the phosphate oxygens, while Zn 2+ shows a much weaker binding specificity.« less

Zinc finger protein rotund deficiency affects development of the thoracic leg in Bombyx mori.

PubMed

Zhou, Chun-Yan; Zha, Xing-Fu; Liu, Hua-Wei; Xia, Qing-You

2017-06-01

The insect limb develops from the imaginal disc or larval leg during metamorphosis. The molecular mechanisms involved in the development from the larval to the adult leg are poorly understood. Herein, we cloned the full length of a zinc finger gene rotund from Bombyx mori (Bmrn), which contained a 1419 bp open reading frame, and encoded a 473 amino acid protein. Reverse transcription polymerase chain reaction and Western blot analyses demonstrated that Bmrn was expressed at higher levels in the epidermis than in other tissues tested, and it showed a very high expression level during metamorphosis. Knock-down of Bmrn produced defects in the tarsus and pretarsus, including the fusion and reduction of tarsomeres, and the developmental arrest of pretarsus. Our data showed that Bmrn is involved in the formation of the tarsus and pretarsus, whereas its homologous gene in Drosophila has been shown to affect three tarsal segments (t2-t4), suggesting that the remodeling of the leg has involved changes in the patterning of gene regulation during evolution. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois

USGS Publications Warehouse

Kay, R.T.; Groschen, G.E.; Cygan, G.; Dupre, David H.

2011-01-01

Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium, and barium may have been affected by competition with Fe+2 for sorption sites on hydrous ferric oxide minerals. ?? 2010.

Zinc starvation induces autophagy in yeast

PubMed Central

Kawamata, Tomoko; Horie, Tetsuro; Matsunami, Miou; Sasaki, Michiko; Ohsumi, Yoshinori

2017-01-01

Zinc is an essential nutrient for all forms of life. Within cells, most zinc is bound to protein. Because zinc serves as a catalytic or structural cofactor for many proteins, cells must maintain zinc homeostasis under severely zinc-deficient conditions. In yeast, the transcription factor Zap1 controls the expression of genes required for uptake and mobilization of zinc, but to date the fate of existing zinc-binding proteins under zinc starvation remains poorly understood. Autophagy is an evolutionarily conserved cellular degradation/recycling process in which cytoplasmic proteins and organelles are sequestered for degradation in the vacuole/lysosome. In this study, we investigated how autophagy functions under zinc starvation. Zinc depletion induced non-selective autophagy, which is important for zinc-limited growth. Induction of autophagy by zinc starvation was not directly related to transcriptional activation of Zap1. Instead, TORC1 inactivation directed zinc starvation-induced autophagy. Abundant zinc proteins, such as Adh1, Fba1, and ribosomal protein Rpl37, were degraded in an autophagy-dependent manner. But the targets of autophagy were not restricted to zinc-binding proteins. When cellular zinc is severely depleted, this non-selective autophagy plays a role in releasing zinc from the degraded proteins and recycling zinc for other essential purposes. PMID:28264932

A moderate increase in dietary zinc reduces DNA strand breaks in leukocytes and alters plasma proteins without changing plasma zinc concentrations123

PubMed Central

Zyba, Sarah J; Killilea, David W; Holland, Tai C; Kim, Elijah; Moy, Adrian; Sutherland, Barbara; Shigenaga, Mark K

2017-01-01

Background: Food fortification has been recommended to improve a population’s micronutrient status. Biofortification techniques modestly elevate the zinc content of cereals, but few studies have reported a positive impact on functional indicators of zinc status. Objective: We determined the impact of a modest increase in dietary zinc that was similar to that provided by biofortification programs on whole-body and cellular indicators of zinc status. Design: Eighteen men participated in a 6-wk controlled consumption study of a low-zinc, rice-based diet. The diet contained 6 mg Zn/d for 2 wk and was followed by 10 mg Zn/d for 4 wk. To reduce zinc absorption, phytate was added to the diet during the initial period. Indicators of zinc homeostasis, including total absorbed zinc (TAZ), the exchangeable zinc pool (EZP), plasma and cellular zinc concentrations, zinc transporter gene expression, and other metabolic indicators (i.e., DNA damage, inflammation, and oxidative stress), were measured before and after each dietary-zinc period. Results: TAZ increased with increased dietary zinc, but plasma zinc concentrations and EZP size were unchanged. Erythrocyte and leukocyte zinc concentrations and zinc transporter expressions were not altered. However, leukocyte DNA strand breaks decreased with increased dietary zinc, and the level of proteins involved in DNA repair and antioxidant and immune functions were restored after the dietary-zinc increase. Conclusions: A moderate 4-mg/d increase in dietary zinc, similar to that which would be expected from zinc-biofortified crops, improves zinc absorption but does not alter plasma zinc. The repair of DNA strand breaks improves, as do serum protein concentrations that are associated with the DNA repair process. This trial was registered at clinicaltrials.gov as NCT02861352. PMID:28003206

Inter- and intra-specific competition of duckweed under multiple heavy metal contaminated water.

PubMed

Zhao, Zhao; Shi, Huijuan; Kang, Xianjiang; Liu, Cunqi; Chen, Lingci; Liang, Xiaofei; Jin, Lei

2017-11-01

The influences of intra- and inter-species competition on ecosystems are poorly understood. Lemna aequinoctialis and Spirodela polyrhiza were used to assess the effects of exposure to different concentrations of multiple heavy metals (copper-cadmium-zinc), when the plants were grown in mixed- or mono-culture. Parameters assessed included relative growth rate (RGR), content of chlorophyll, glutathione (GSH), malondialdehyde (MDA), as well as the activity of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD). Inter-specific competition was affected by metal concentration, with results indicating that inter-specific competition significantly affected duckweed growth and metal uptake in different heavy metal exposure conditions. Inter-specific competition increased growth rate of duckweed under high metal concentrations, although when compared with intra-specific competition, it caused no obvious differences under low metal concentrations. The growth of L. aequinoctialis was further increased in mixed culture when exposed to high metal concentrations, with inter-specific competition increasing the content of cadmium and zinc, while decreasing copper content of L. aequinoctialis compared with under intra-specific conditions. Conversely, inter-specific competition increased the content of copper and cadmium of S. polyrhiza, without causing obvious differences in zinc accumulation under high ambient concentrations. Under high metal conditions, inter-specific competition increased antioxidant enzyme activities in duckweed species, increasing resistance to heavy metals. Results show that inter-specific competition makes duckweed develop mechanisms to increase fitness and survival, such as enhancement of antioxidant enzyme activities, rather than limiting metal uptake when exposed to high concentrations of multiple metals. Copyright © 2017 Elsevier B.V. All rights reserved.

Toxicity of marine pollutants on the ascidian oocyte physiology: an electrophysiological approach.

PubMed

Gallo, Alessandra

2018-02-01

In marine animals with external fertilization, gametes are released into seawater where fertilization and embryo development occur. Consequently, pollutants introduced into the marine environment by human activities may affect gametes and embryos. These xenobiotics can alter cell physiology with consequent reduction of fertilization success. Here the adverse effects on the reproductive processes of the marine invertebrate Ciona intestinalis (ascidian) of different xenobiotics: lead, zinc, an organic tin compound and a phenylurea herbicide were evaluated. By using the electrophysiological technique of whole-cell voltage clamping, the effects of these compounds on the mature oocyte plasma membrane electrical properties and the electrical events of fertilization were tested by calculating the concentration that induced 50% normal larval formation (EC50). The results demonstrated that sodium currents in mature oocytes were reduced in a concentration-dependent manner by all tested xenobiotics, with the lowest EC50 value for lead. In contrast, fertilization current frequencies were differently affected by zinc and organic tin compound. Toxicity tests on gametes demonstrated that sperm fertilizing capability and fertilization oocyte competence were not altered by xenobiotics, whereas fertilization was inhibited in zinc solution and underwent a reduction in organic tin compound solution (EC50 value of 1.7 µM). Furthermore, fertilized oocytes resulted in a low percentage of normal larvae with an EC50 value of 0.90 µM. This study shows that reproductive processes of ascidians are highly sensitive to xenobiotics suggesting that they may be considered a reliable biomarker and that ascidians are suitable model organisms to assess marine environmental quality.

DPL-1 DP, LIN-35 Rb and EFL-1 E2F act with the MCD-1 zinc-finger protein to promote programmed cell death in Caenorhabditis elegans.

PubMed

Reddien, Peter W; Andersen, Erik C; Huang, Michael C; Horvitz, H Robert

2007-04-01

The genes egl-1, ced-9, ced-4, and ced-3 play major roles in programmed cell death in Caenorhabditis elegans. To identify genes that have more subtle activities, we sought mutations that confer strong cell-death defects in a genetically sensitized mutant background. Specifically, we screened for mutations that enhance the cell-death defects caused by a partial loss-of-function allele of the ced-3 caspase gene. We identified mutations in two genes not previously known to affect cell death, dpl-1 and mcd-1 (modifier of cell death). dpl-1 encodes the C. elegans homolog of DP, the human E2F-heterodimerization partner. By testing genes known to interact with dpl-1, we identified roles in cell death for four additional genes: efl-1 E2F, lin-35 Rb, lin-37 Mip40, and lin-52 dLin52. mcd-1 encodes a novel protein that contains one zinc finger and that is synthetically required with lin-35 Rb for animal viability. dpl-1 and mcd-1 act with efl-1 E2F and lin-35 Rb to promote programmed cell death and do so by regulating the killing process rather than by affecting the decision between survival and death. We propose that the DPL-1 DP, MCD-1 zinc finger, EFL-1 E2F, LIN-35 Rb, LIN-37 Mip40, and LIN-52 dLin52 proteins act together in transcriptional regulation to promote programmed cell death.

Addition of zinc methacrylate in dental polymers: MMP-2 inhibition and ultimate tensile strength evaluation.

PubMed

Henn, Sandrina; de Carvalho, Rodrigo Varella; Ogliari, Fabrício Aulo; de Souza, Ana Paula; Line, Sergio Roberto Peres; da Silva, Adriana Fernandes; Demarco, Flávio Fernando; Etges, Adriana; Piva, Evandro

2012-04-01

This study evaluated the effect of zinc methacrylate (ZM) on the inhibition of matrix metalloproteinase 2 (MMP-2) and the ultimate tensile strength (UTS) of an experimental polymer. Enzymes secreted from mouse gingival tissues were analyzed by gelatin zymography in buffers containing 5 mM CaCl(2) (Tris-CaCl(2)) in 50 mM Tris-HCl buffer with various concentrations of ZM (0.5, 1, 2, 4, 8, and 16 mM). The matrix metalloproteinases present in the conditioned media were characterized by immunoprecipitation. The polymer UTS evaluation was performed in eight groups with various concentrations of ZM (0, 0.5, 1, 2.5, 5, 10, 20, and 30 wt.%), in a mechanical testing machine. MMP-2 (62 kDa) was detected in the zymographic assays and inhibited by ZM in all tested concentrations. UTS data were submitted to one-way ANOVA and Tukey's test (α = 0.05), and no significant differences were observed among groups, except in the polymer containing 30% ZM, presenting a significantly lower value when compared with the control group (p < 0.05). The results suggest that ZM inhibits MMP-2 expression in all concentrations tested, while small concentrations did not affect the ultimate tensile strength of the polymer. Zinc methacrylate is a metalloproteinase inhibitor that can be copolymerized with other methacrylate monomers. Yet, the addition of ZM did not affect the resin bond strength. Thus, in vivo tests should be performed to evaluate the performance of this material.

Polarization studies on zinc in hydrochloric acid solution containing some organic solvents

NASA Astrophysics Data System (ADS)

Mohamed, A. K.

1999-05-01

The corrosion behaviour of zinc metal in some organic solvents was tested electrochemically using galvanometric polarization measurements. The results showed that the studied organic solvents act as mixed type inhibitors. The inhibition was assumed to occur via physical adsorption of the inhibitor molecules fitting a Temkin's isotherm. The inhibition eficiency of the solvents increase in the order: glycerol>ethylene glycol>DMSO>dioxane. This order is not affected by the variation in temperature in the range 35-55 circC. The increase in temperature was found to increase the corrosion in absence and in presence of inhibitors. Some thermodynamic parameters for adsorption were also computed and discussed. Le comportement de corrosion du zinc métallique dans certains solvants organiques a été testé électrochimiquement en utilisant les mesures de polarisation galvanométrique. Les résultats ont montré que les solvants organiques étudiés agissent comme des inhibiteurs de type mixte. L'inhibition semble se produire par l'adsorption physique des molécules inhibitrices selon une isotherme de Temkin. L'efficacité d'inhibition des solvants augmente dans l'ordre suivant : glycérol>éthylène glycol>DMSO>dioxane. Cet ordre n'est pas affecté par une variation de température dans l'intervalle compris entre 35 et 55 circC. La corrosion augmente avec la température, en absence ou en présence d'inhibiteurs. Certains paramètres thermodynamiques d'adsorption ont été calculés et discutés.

Zinc as a Gatekeeper of Immune Function

PubMed Central

Wessels, Inga; Maywald, Martina; Rink, Lothar

2017-01-01

After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells. Zinc homeostasis is largely controlled via the expression and action of zinc “importers” (ZIP 1–14), zinc “exporters” (ZnT 1–10), and zinc-binding proteins. Anti-inflammatory and anti-oxidant properties of zinc have long been documented, however, underlying mechanisms are still not entirely clear. Here, we report molecular mechanisms underlying the development of a pro-inflammatory phenotype during zinc deficiency. Furthermore, we describe links between altered zinc homeostasis and disease development. Consequently, the benefits of zinc supplementation for a malfunctioning immune system become clear. This article will focus on underlying mechanisms responsible for the regulation of cellular signaling by alterations in zinc homeostasis. Effects of fast zinc flux, intermediate “zinc waves”, and late homeostatic zinc signals will be discriminated. Description of zinc homeostasis-related effects on the activation of key signaling molecules, as well as on epigenetic modifications, are included to emphasize the role of zinc as a gatekeeper of immune function. PMID:29186856

Zinc starvation induces autophagy in yeast.

PubMed

Kawamata, Tomoko; Horie, Tetsuro; Matsunami, Miou; Sasaki, Michiko; Ohsumi, Yoshinori

2017-05-19

Zinc is an essential nutrient for all forms of life. Within cells, most zinc is bound to protein. Because zinc serves as a catalytic or structural cofactor for many proteins, cells must maintain zinc homeostasis under severely zinc-deficient conditions. In yeast, the transcription factor Zap1 controls the expression of genes required for uptake and mobilization of zinc, but to date the fate of existing zinc-binding proteins under zinc starvation remains poorly understood. Autophagy is an evolutionarily conserved cellular degradation/recycling process in which cytoplasmic proteins and organelles are sequestered for degradation in the vacuole/lysosome. In this study, we investigated how autophagy functions under zinc starvation. Zinc depletion induced non-selective autophagy, which is important for zinc-limited growth. Induction of autophagy by zinc starvation was not directly related to transcriptional activation of Zap1. Instead, TORC1 inactivation directed zinc starvation-induced autophagy. Abundant zinc proteins, such as Adh1, Fba1, and ribosomal protein Rpl37, were degraded in an autophagy-dependent manner. But the targets of autophagy were not restricted to zinc-binding proteins. When cellular zinc is severely depleted, this non-selective autophagy plays a role in releasing zinc from the degraded proteins and recycling zinc for other essential purposes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of tire leachate on the invasive mosquito Aedes albopictus and the native congener Aedes triseriatus.

PubMed

Villena, Oswaldo C; Terry, Ivana; Iwata, Kayoko; Landa, Edward R; LaDeau, Shannon L; Leisnham, Paul T

2017-01-01

Discarded vehicle tire casings are an important artificial habitat for the developmental stages of numerous vector mosquitoes. Discarded vehicle tires degrade under ultraviolet light and leach numerous soluble metals (e.g., barium, cadmium, zinc) and organic substances (e.g., benzothiazole and its derivatives [BZTs], polyaromatic hydrocarbons [PAHs]) that could affect mosquito larvae that inhabit the tire casing. This study examined the relationship between soluble zinc, a common marker of tire leachate, on mosquito densities in tire habitats in the field, and tested the effects of tire leachate on the survival and development of newly hatched Aedes albopictus and Aedes triseriatus larvae in a controlled laboratory dose-response experiment. In the field, zinc concentrations were as high as 7.26 mg/L in a single tire and averaged as high as 2.39 (SE ± 1.17) mg/L among tires at a single site. Aedes albopictus (37/42 tires, 81.1%) and A. triseriatus (23/42, 54.8%) were the most widespread mosquito species, co-occurred in over half (22/42, 52.4%) of all tires, and A. triseriatus was only collected without A. albopictus in one tire. Aedes triseriatus was more strongly negatively associated with zinc concentration than A. albopictus, and another common mosquito, C. pipiens, which was found in 17 tires. In the laboratory experiment, A. albopictus per capita rate of population change ( λ ') was over 1.0, indicating positive population growth, from 0-8.9 mg/L zinc concentration (0-10,000 mg/L tire leachate), but steeply declined to zero from 44.50-89.00 mg/L zinc (50,000-100,000 mg/L tire leachate). In contrast, A. triseriatus λ ' declined at the lower concentration of 0.05 mg/L zinc (100 mg/L tire leachate), and was zero at 0.45, 8.90, 44.50, and 89.00 mg/L zinc (500, 10,000, 50,000 and 100,000 mg/L tire leachate). These results indicate that tire leachate can have severe negative effects on populations of container-utilizing mosquitoes at concentrations commonly found in the field. Superior tolerance to tire leachate of A. albopictus compared to A. triseriatus, and possibly other native mosquito species, may have facilitated the replacement of these native species as A. albopictus has invaded North America and other regions around the world.

Effects of tire leachate on the invasive mosquito Aedes albopictus and the native congener Aedes triseriatus

PubMed Central

Villena, Oswaldo C.; Terry, Ivana; Iwata, Kayoko; Landa, Edward R.; LaDeau, Shannon L.

2017-01-01

Discarded vehicle tire casings are an important artificial habitat for the developmental stages of numerous vector mosquitoes. Discarded vehicle tires degrade under ultraviolet light and leach numerous soluble metals (e.g., barium, cadmium, zinc) and organic substances (e.g., benzothiazole and its derivatives [BZTs], polyaromatic hydrocarbons [PAHs]) that could affect mosquito larvae that inhabit the tire casing. This study examined the relationship between soluble zinc, a common marker of tire leachate, on mosquito densities in tire habitats in the field, and tested the effects of tire leachate on the survival and development of newly hatched Aedes albopictus and Aedes triseriatus larvae in a controlled laboratory dose-response experiment. In the field, zinc concentrations were as high as 7.26 mg/L in a single tire and averaged as high as 2.39 (SE ± 1.17) mg/L among tires at a single site. Aedes albopictus (37/42 tires, 81.1%) and A. triseriatus (23/42, 54.8%) were the most widespread mosquito species, co-occurred in over half (22/42, 52.4%) of all tires, and A. triseriatus was only collected without A. albopictus in one tire. Aedes triseriatus was more strongly negatively associated with zinc concentration than A. albopictus, and another common mosquito, C. pipiens, which was found in 17 tires. In the laboratory experiment, A. albopictus per capita rate of population change (λ′) was over 1.0, indicating positive population growth, from 0–8.9 mg/L zinc concentration (0–10,000 mg/L tire leachate), but steeply declined to zero from 44.50–89.00 mg/L zinc (50,000–100,000 mg/L tire leachate). In contrast, A. triseriatus λ′ declined at the lower concentration of 0.05 mg/L zinc (100 mg/L tire leachate), and was zero at 0.45, 8.90, 44.50, and 89.00 mg/L zinc (500, 10,000, 50,000 and 100,000 mg/L tire leachate). These results indicate that tire leachate can have severe negative effects on populations of container-utilizing mosquitoes at concentrations commonly found in the field. Superior tolerance to tire leachate of A. albopictus compared to A. triseriatus, and possibly other native mosquito species, may have facilitated the replacement of these native species as A. albopictus has invaded North America and other regions around the world. PMID:28890855

Intracellular zinc distribution in mitochondria, ER and the Golgi apparatus

PubMed Central

Lu, Qiping; Haragopal, Hariprakash; Slepchenko, Kira G; Stork, Christian; Li, Yang V

2016-01-01

Zinc (Zn2+) is required for numerous cellular functions. As such, the homeostasis and distribution of intracellular zinc can influence cellular metabolism and signaling. However, the exact distribution of free zinc within live cells remains elusive. Previously we showed the release of zinc from thapsigargin/IP3-sensitive endoplasmic reticulum (ER) storage in cortical neurons. In the present study, we investigated if other cellular organelles also contain free chelatable zinc and function as organelle storage for zinc. To identify free zinc within the organelles, live cells were co-stained with Zinpyr-1, a zinc fluorescent dye, and organelle-specific fluorescent dyes (MitoFluor Red 589: mitochondria; ER Tracker Red: endoplasmic reticulum; BODIPY TR ceramide: Golgi apparatus; Syto Red 64: nucleus). We examined organelles that represent potential storing sites for intracellular zinc. We showed that zinc fluorescence staining was co-localized with MitoFluor Red 589, ER Tracker Red, and BODIPY TR ceramide respectively, suggesting the presence of free zinc in mitochondria, endoplasmic reticulum, and the Golgi apparatus. On the other hand, cytosol and nucleus had nearly no detectable zinc fluorescence. It is known that nucleus contains high amount of zinc binding proteins that have high zinc binding affinity. The absence of zinc fluorescence suggests that there is little free zinc in these two regions. It also indicates that the zinc fluorescence detected in mitochondria, ER and Golgi apparatus represents free chelatable zinc. Taken together, our results support that these organelles are potential zinc storing organelles during cellular zinc homeostasis. PMID:27186321

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

Dendrochemical patterns of calcium, zinc, and potassium related to internal factors detected by energy dispersive X-ray fluorescence (EDXRF)

USGS Publications Warehouse

Smith, Kevin T.; Balouet, Jean Christophe; Shortle, Walter C.; Chalot, Michel; Beaujard, François; Grudd, Håkan; Vroblesky, Don A.; Burkem, Joel G.

2014-01-01

Energy dispersive X-ray fluorescence (EDXRF) provides highly sensitive and precise spatial resolution of cation content in individual annual growth rings in trees. The sensitivity and precision have prompted successful applications to forensic dendrochemistry and the timing of environmental releases of contaminants. These applications have highlighted the need to distinguish dendrochemical effects of internal processes from environmental contamination. Calcium, potassium, and zinc are three marker cations that illustrate the influence of these processes. We found changes in cation chemistry in tree rings potentially due to biomineralization, development of cracks or checks, heartwood/sapwood differentiation, intra-annual processes, and compartmentalization of infection. Distinguishing internal from external processes that affect dendrochemistry will enhance the value of EDXRF for both physiological and forensic investigations.

Sequoia, a tramtrack-related zinc finger protein, functions as a pan-neural regulator for dendrite and axon morphogenesis in Drosophila.

PubMed

Brenman, J E; Gao, F B; Jan, L Y; Jan, Y N

2001-11-01

Morphological complexity of neurons contributes to their functional complexity. How neurons generate different dendritic patterns is not known. We identified the sequoia mutant from a previous screen for dendrite mutants. Here we report that Sequoia is a pan-neural nuclear protein containing two putative zinc fingers homologous to the DNA binding domain of Tramtrack. sequoia mutants affect the cell fate decision of a small subset of neurons but have global effects on axon and dendrite morphologies of most and possibly all neurons. In support of sequoia as a specific regulator of neuronal morphogenesis, microarray experiments indicate that sequoia may regulate downstream genes that are important for executing neurite development rather than altering a variety of molecules that specify cell fates.

Modification of FN tunneling provoking gate-leakage current in ZTO (zinc-tin oxide) TFT by regulating the ZTO/SiO2 area ratio

NASA Astrophysics Data System (ADS)

Li, Jeng-Ting; Tsai, Ho-Lin; Lai, Wei-Yao; Hwang, Weng-Sing; Chen, In-Gann; Chen, Jen-Sue

2018-04-01

This study addresses the variation in gate-leakage current due to the Fowler-Nordheim (FN) tunneling of electrons through a SiO2 dielectric layer in zinc-tin oxide (ZTO) thin film transistors. It is shown that the gate-leakage current is not related to the absolute area of the ZTO active layer, but it is reduced by reducing the ZTO/SiO2 area ratio. The ZTO/SiO2 area ratio modulates the ZTO-SiO2 interface dipole strength as well as the ZTO-SiO2 conduction band offset and subsequently affects the FN tunneling current through the SiO2 layer, which provides a route that modifies the gate-leakage current.

The site of antiviral action of 3-nitrosobenzamide on the infectivity process of human immunodeficiency virus in human lymphocytes.

PubMed Central

Rice, W G; Schaeffer, C A; Graham, L; Bu, M; McDougal, J S; Orloff, S L; Villinger, F; Young, M; Oroszlan, S; Fesen, M R

1993-01-01

The C-nitroso compound 3-nitrosobenzamide, which has been shown to remove zinc from the retroviral-type zinc finger of p7NC nucleocapsid proteins, inhibits acute infection of human immunodeficiency virus type 1 in cultured human lymphocytes. The attachment of the virus to lymphocytes and the activities of critical viral enzymes, such as reverse transcriptase, protease, and integrase, are not affected by 3-nitrosobenzamide. However, the process of reverse transcription to form proviral DNA is effectively abolished by the drug, identifying the mode of action of 3-nitrosobenzamide as interrupting the role of p7NC in accurate proviral DNA synthesis during the infectious phase of the virus life cycle. Images Fig. 3 Fig. 4 PMID:7692451

Modulations of anisotropic optical transmission on alumina-doped zinc oxide surface by femtosecond laser induced ripples

NASA Astrophysics Data System (ADS)

Lu, Yanhui; Jiang, Lan; Sun, Jingya; Cao, Qiang; Wang, Qingsong; Han, Weina; Lu, Yongfeng

2018-04-01

This study demonstrated that femtosecond-laser-induced ripples on an alumina-doped zinc oxide (AZO) film with space intervals of approximately 340 and 660 nm exhibit modulations of anisotropic optical transmission. At low laser fluence, ripples can not affect the original absorption peak of AZO film, but at higher laser fluence, the absorption peak of AZO film is disappeared due to the modulation by femtosecond laser induced ripples. Moreover, the relationship between the anisotropic optical transmission and the features of nanostructures is discussed. Ripples with a space interval of approximately 660 nm have a higher ability to block light than nanostructures with a space interval of approximately 340 nm. These observations indicate that anisotropic optical transmission has potential applications in the field of optoelectronics.

Effect of zinc and benzene on respiration and excretion of mussel larvae (Perna perna) (Linnaeus, 1758) (Mollusca; Bivalvia).

PubMed

Jorge, R A D L V C; Lemos, D; Moreira, G S

2007-02-01

The presence of pollutants in the ocean may affect different physiological parameters of animals. Oxygen consumption and ammonia excretion were evaluated in D-shaped larvae of mussels (Perna perna) exposed to zinc sulphate (ZnSO(4)) and benzene (C(6)H(6)). When compared to the control group, both pollutants presented a significant reduction in oxygen consumption. A reduction in the ammonia excretion was also observed, both for ZnSO(4) and C(6)H(6) and also in the oxygen consumption. The results indicate that anaerobic metabolism may occur at the beginning of P. perna mussels development, as observed in veliger larvae. The O:N ratio under experimental conditions showed low values indicating that catabolism in veliger larvae was predominantly proteic.

Plasma zinc's alter ego is a low-molecular-weight humoral factor.

PubMed

Ou, Ou; Allen-Redpath, Keith; Urgast, Dagmar; Gordon, Margaret-Jane; Campbell, Gill; Feldmann, Jörg; Nixon, Graeme F; Mayer, Claus-Dieter; Kwun, In-Sook; Beattie, John H

2013-09-01

Mild dietary zinc deprivation in humans and rodents has little effect on blood plasma zinc levels, and yet cellular consequences of zinc depletion can be detected in vascular and other tissues. We proposed that a zinc-regulated humoral factor might mediate the effects of zinc deprivation. Using a novel approach, primary rat vascular smooth muscle cells (VSMCs) were treated with plasma from zinc-deficient (<1 mg Zn/kg) or zinc-adequate (35 mg Zn/kg, pair-fed) adult male rats, and zinc levels were manipulated to distinguish direct and indirect effects of plasma zinc. Gene expression changes were analyzed by microarray and qPCR, and incubation of VSMCs with blood plasma from zinc-deficient rats strongly changed the expression of >2500 genes, compared to incubation of cells with zinc-adequate rat plasma. We demonstrated that this effect was caused by a low-molecular-weight (∼2-kDa) zinc-regulated humoral factor but that changes in gene expression were mostly reversed by adding zinc back to zinc-deficient plasma. Strongly regulated genes were overrepresented in pathways associated with immune function and development. We conclude that zinc deficiency induces the production of a low-molecular-weight humoral factor whose influence on VSMC gene expression is blocked by plasma zinc. This factor is therefore under dual control by zinc.

Uptake and partitioning of zinc in Lemnaceae.

PubMed

Lahive, Elma; O'Callaghan, Michael J A; Jansen, Marcel A K; O'Halloran, John

2011-11-01

Macrophytes provide food and shelter for aquatic invertebrates and fish, while also acting as reservoirs for nutrients and trace elements. Zinc accumulation has been reported for various Lemnaceae species. However, comparative accumulation across species and the link between zinc accumulation and toxicity are poorly understood. Morphological distribution and cellular storage, in either bound or soluble form, are important for zinc tolerance. This study shows differences in the uptake and accumulation of zinc by three duckweed species. Landoltia punctata and Lemna minor generally accumulated more zinc than Lemna gibba. L. minor, but not L. gibba or L. punctata, accumulated greater concentrations of zinc in roots compared to fronds when exposed to high levels of zinc. The proportion of zinc stored in the bound form relative to the soluble-form was higher in L. minor. L. punctata accumulated greater concentrations of zinc in fronds compared to roots and increased the proportion of zinc it stored in the soluble form, when exposed to high zinc levels. L. gibba is the only species that significantly accumulated zinc at low concentrations, and was zinc-sensitive. Overall, internal zinc concentrations showed no consistent correlation with toxic effect. We conclude that relationships between zinc toxicity and uptake and accumulation are species specific reflecting, among others, zinc distribution and storage. Differences in zinc distribution and storage are also likely to have implications for zinc bioavailability and trophic mobility.

Modulation of extrasynaptic NMDA receptors by synaptic and tonic zinc.

PubMed

Anderson, Charles T; Radford, Robert J; Zastrow, Melissa L; Zhang, Daniel Y; Apfel, Ulf-Peter; Lippard, Stephen J; Tzounopoulos, Thanos

2015-05-19

Many excitatory synapses contain high levels of mobile zinc within glutamatergic vesicles. Although synaptic zinc and glutamate are coreleased, it is controversial whether zinc diffuses away from the release site or whether it remains bound to presynaptic membranes or proteins after its release. To study zinc transmission and quantify zinc levels, we required a high-affinity rapid zinc chelator as well as an extracellular ratiometric fluorescent zinc sensor. We demonstrate that tricine, considered a preferred chelator for studying the role of synaptic zinc, is unable to efficiently prevent zinc from binding low-nanomolar zinc-binding sites, such as the high-affinity zinc-binding site found in NMDA receptors (NMDARs). Here, we used ZX1, which has a 1 nM zinc dissociation constant and second-order rate constant for binding zinc that is 200-fold higher than those for tricine and CaEDTA. We find that synaptic zinc is phasically released during action potentials. In response to short trains of presynaptic stimulation, synaptic zinc diffuses beyond the synaptic cleft where it inhibits extrasynaptic NMDARs. During higher rates of presynaptic stimulation, released glutamate activates additional extrasynaptic NMDARs that are not reached by synaptically released zinc, but which are inhibited by ambient, tonic levels of nonsynaptic zinc. By performing a ratiometric evaluation of extracellular zinc levels in the dorsal cochlear nucleus, we determined the tonic zinc levels to be low nanomolar. These results demonstrate a physiological role for endogenous synaptic as well as tonic zinc in inhibiting extrasynaptic NMDARs and thereby fine tuning neuronal excitability and signaling.

Modulation of extrasynaptic NMDA receptors by synaptic and tonic zinc

PubMed Central

Anderson, Charles T.; Radford, Robert J.; Zastrow, Melissa L.; Zhang, Daniel Y.; Apfel, Ulf-Peter; Lippard, Stephen J.; Tzounopoulos, Thanos

2015-01-01

Many excitatory synapses contain high levels of mobile zinc within glutamatergic vesicles. Although synaptic zinc and glutamate are coreleased, it is controversial whether zinc diffuses away from the release site or whether it remains bound to presynaptic membranes or proteins after its release. To study zinc transmission and quantify zinc levels, we required a high-affinity rapid zinc chelator as well as an extracellular ratiometric fluorescent zinc sensor. We demonstrate that tricine, considered a preferred chelator for studying the role of synaptic zinc, is unable to efficiently prevent zinc from binding low-nanomolar zinc-binding sites, such as the high-affinity zinc-binding site found in NMDA receptors (NMDARs). Here, we used ZX1, which has a 1 nM zinc dissociation constant and second-order rate constant for binding zinc that is 200-fold higher than those for tricine and CaEDTA. We find that synaptic zinc is phasically released during action potentials. In response to short trains of presynaptic stimulation, synaptic zinc diffuses beyond the synaptic cleft where it inhibits extrasynaptic NMDARs. During higher rates of presynaptic stimulation, released glutamate activates additional extrasynaptic NMDARs that are not reached by synaptically released zinc, but which are inhibited by ambient, tonic levels of nonsynaptic zinc. By performing a ratiometric evaluation of extracellular zinc levels in the dorsal cochlear nucleus, we determined the tonic zinc levels to be low nanomolar. These results demonstrate a physiological role for endogenous synaptic as well as tonic zinc in inhibiting extrasynaptic NMDARs and thereby fine tuning neuronal excitability and signaling. PMID:25947151

Zinc: an essential but elusive nutrient123

PubMed Central

King, Janet C

2011-01-01

Zinc is essential for multiple aspects of metabolism. Physiologic signs of zinc depletion are linked with diverse biochemical functions rather than with a specific function, which makes it difficult to identify biomarkers of zinc nutrition. Nutrients, such as zinc, that are required for general metabolism are called type 2 nutrients. Protein and magnesium are examples of other type 2 nutrients. Type 1 nutrients are required for one or more specific functions: examples include iron, vitamin A, iodine, folate, and copper. When dietary zinc is insufficient, a marked reduction in endogenous zinc loss occurs immediately to conserve the nutrient. If zinc balance is not reestablished, other metabolic adjustments occur to mobilize zinc from small body pools. The location of those pools is not known, but all cells probably have a small zinc reserve that includes zinc bound to metallothionein or zinc stored in the Golgi or in other organelles. Plasma zinc is also part of this small zinc pool that is vulnerable to insufficient intakes. Plasma zinc concentrations decline rapidly with severe deficiencies and more moderately with marginal depletion. Unfortunately, plasma zinc concentrations also decrease with a number of conditions (eg, infection, trauma, stress, steroid use, after a meal) due to a metabolic redistribution of zinc from the plasma to the tissues. This redistribution confounds the interpretation of low plasma zinc concentrations. Biomarkers of metabolic zinc redistribution are needed to determine whether this redistribution is the cause of a low plasma zinc rather than poor nutrition. Measures of metallothionein or cellular zinc transporters may fulfill that role. PMID:21715515

Prediction of Serum Zinc Levels in Mexican Children at 2 Years of Age Using a Food Frequency Questionnaire and Different Zinc Bioavailability Criteria

PubMed Central

Cantoral, Alejandra; Téllez-Rojo, Martha; Shamah-Levy, Teresa; Schnaas, Lourdes; Hernández-Ávila, Mauricio; Peterson, Karen; Ettinger, Adrienne

2017-01-01

Background The 2006 Mexican National Health and Nutrition Survey documented a prevalence of zinc deficiency of almost 30% in children aged one to two years old. Objective We sought to validate a Food Frequency Questionnaire (FFQ) for quantifying dietary bioavailable zinc intake in two-year old Mexican children accounting for phytic acid intake and using serum zinc as a reference. Methods This cross-sectional study was nested within a longitudinal birth cohort of 333 young children in Mexico City. Non-fasting serum zinc concentration was measured and dietary zinc intake was calculated on the basis of a semi-quantitative FFQ administered to their mothers. The relationship between dietary zinc intake and serum zinc was assessed using linear regression, adjusting for phytic acid intake, and analyzed according to two distinct international criteria to estimate bioavailable zinc. Models were stratified by zinc deficiency status. Results Dietary zinc, adjusted for phytic acid intake, explained the greatest proportion of the variance of serum zinc. For each mg of dietary zinc intake, serum zinc increased on average by 0.95 μg/dL (0.15 μmol/L) (p=0.06). When stratified by zinc status, this increase was 0.74 μg/dL (p=0.12) for each milligram of zinc consumed among children with adequate serum zinc (N=276) whereas among those children with zinc deficiency (N=57), serum zinc increased by only 0.11 μg/dL (p=0.82). Conclusion A semi-quantitative FFQ can be used for predicting serum zinc in relation to dietary intake in young children, particularly among those who are zinc-replete, and when phytic acid/phytate intake is considered. Future studies should be conducted accounting for both zinc status and dietary zinc inhibitors to further elucidate and validate these findings. PMID:26121697

Roadside soils show low plant available zinc and copper concentrations.

PubMed

Morse, Natalie; Walter, M Todd; Osmond, Deanna; Hunt, William

2016-02-01

Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day(-1)), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to "total metal", the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site. Copyright © 2015 Elsevier Ltd. All rights reserved.

Main biomarkers associated with age-related plasma zinc decrease and copper/zinc ratio in healthy elderly from ZincAge study.

PubMed

Giacconi, R; Costarelli, L; Piacenza, F; Basso, A; Rink, L; Mariani, E; Fulop, T; Dedoussis, G; Herbein, G; Provinciali, M; Jajte, J; Lengyel, I; Mocchegiani, E; Malavolta, M

2017-12-01

Zinc (Zn) plays an essential role in many biological processes including immune response. Impaired Zn status promotes immune dysfunction, and it has been associated with enhanced chronic inflammation during aging. It has been suggested that the measurement of circulating Zn by itself could not reflect the real Zn status of an individual. It is therefore necessary to identify other determinants associated with plasma Zn to better understanding how physiopathological conditions during aging may affect the concentration of this metal. We have investigated the association between Zn levels and some biomarkers in 1090 healthy elderly from five European countries to increase the accuracy in the assessment of the Zn status. Stepwise multivariate linear regression models were used to analyze the influence of factors such as age, dietary intake, inflammatory mediators, laboratory parameters and polymorphisms previously associated with Zn homeostasis. Plasma Zn decrement was most strongly predicted by age, while positive correlations were found with albumin, RANTES and Zn intake after adjustment for multiple confounders. HSP70 +1267 AA genotype was an independent factor associated with Zn plasma concentrations. Cu/Zn ratio was positively associated with markers of systemic inflammation and age and negatively associated with albumin serum levels. Our findings show the most important independent determinants of plasma Zn concentration and Cu/Zn ratio variability in elderly population and suggest that the decline with age of Zn circulating levels is more dependent on physiopathological changes occurring with aging rather than to its nutritional intake.

Copper, zinc, and cadmium in various fractions of soil and fungi in a Swedish forest.

PubMed

Vinichuk, Mykhailo M

2013-01-01

Ectomycorrhizal fungi profoundly affect forest ecosystems through mediating nutrient uptake and maintaining forest food webs. The accumulation of metals in each transfer step from bulk soil to fungal sporocarps is not well known. The accumulation of three metals copper (Cu), zinc (Zn) and cadmium (Cd) in bulk soil, rhizosphere, soil-root interface, fungal mycelium and sporocarps of mycorrhizal fungi in a Swedish forest were compared. Concentrations of all three metals increased in the order: bulk soil < soil-root interface (or rhizosphere) < fungal mycelium < fungal sporocarps. The uptake of Cu, Zn and Cd during the entire transfer process in natural conditions between soil and sporocarps occurred against a concentration gradient. In fungal mycelium, the concentration of all three metals was about three times higher than in bulk soil, and the concentration in sporocarps was about two times higher than in mycelium. In terms of accumulation, fungi (mycelium and sporocarps) preferred Cd to Zn and Cu. Zinc concentration in sporocarps and to a lesser extent in mycelium depended on the concentration in soil, whereas, the uptake of Cu and Cd by both sporocarps and mycelium did not correlate with metal concentration in soil. Heavy metal accumulation within the fungal mycelium biomass in the top forest soil layer (0-5 cm) might account for ca. 5-9% of the total amount of Cu, 5-11% of Zn, and 16-32% of Cd. As the uptake of zinc and copper by fungi may be balanced, this implied similarities in the uptake mechanism.

Trace metals in the brain: allosteric modulators of ligand-gated receptor channels, the case of ATP-gated P2X receptors.

PubMed

Huidobro-Toro, J Pablo; Lorca, Ramón A; Coddou, Claudio

2008-03-01

Zinc and copper are indispensable trace metals for life with a recognized role as catalysts in enzyme actions. We now review evidence supporting the role of trace metals as novel allosteric modulators of ionotropic receptors: a new and fundamental physiological role for zinc and copper in neuronal and brain excitability. The review is focussed on ionotropic receptor channels including nucleotide receptors, in particular the P2X receptor family. Since zinc and copper are stored within synaptic vesicles in selected brain regions, and released to the synaptic cleft upon electrical nerve ending depolarization, it is plausible that zinc and copper reach concentrations in the synapse that profoundly affect ligand-gated ionic channels, including the ATP-gated currents of P2X receptors. The identification of key P2X receptor amino acids that act as ligands for trace metal coordination, carves the structural determinants underlying the allosteric nature of the trace metal modulation. The recognition that the identified key residues such as histidines, aspartic and glutamic acids or cysteines in the extracellular domain are different for each P2X receptor subtype and may be different for each metal, highlights the notion that each P2X receptor subtype evolved independent strategies for metal coordination, which form upon the proper three-dimensional folding of the receptor channels. The understanding of the molecular mechanism of allosteric modulation of ligand-operated ionic channels by trace metals is a new contribution to metallo-neurobiology.

A Rapid Deposition of Fluorine Doped Zinc Oxide Using the Atmospheric Pressure Chemical Vapour Deposition Method

NASA Astrophysics Data System (ADS)

Najafi, Navid; Rozati, S. M.

2018-03-01

Fluorine-doped zinc oxide (FZO) (ZnO:F) thin films were manufactured by atmospheric pressure chemical vapor deposition (APCVD) on glass substrates using zinc acetate dihydrate [C4H6O4Zn·2H2O, ZnAc] and ammonium fluoride (NH4F) as the source of fluorine with deposition duration of only 120 s for each sample. The effects of different amounts of fluorine as the dopant on the structural, electrical and optical properties of FZO thin films were investigated. The results show a polycrystalline structure at higher temperatures compared to amorphous structure at lower temperatures. The x-ray diffraction patterns of the polycrystalline films were identified as a hexagonal wurtzite structure of zinc oxide (ZnO) with the (002) preferred orientation. Also, the sheet resistance decreased from 17.8 MΩ/□ to 28.9 KΩ/□ for temperatures 325°C to 450°C, respectively. In order to further decrease the sheet resistance of the undoped ZnO thin films, fluorine was added using NH4F as the precursor, and again a drastic change in sheet resistance of only 17.7 Ω/□ was obtained. Based on the field emission scanning electron microscopy images, the fluorine concentration in CVD source is an important factor affecting the grain size and modifies electrical parameters. Ultraviolet-visible measurements revealed reduction of transparency of the layers with increasing fluorine as the dopant.

Nutrition for brain recovery after ischemic stroke: an added value to rehabilitation.

PubMed

Aquilani, Roberto; Sessarego, Paolo; Iadarola, Paolo; Barbieri, Annalisa; Boschi, Federica

2011-06-01

In patients who undergo rehabilitation after ischemic stroke, nutrition strategies are adopted to provide tube-fed individuals with adequate nutrition and/or to avoid the body wasting responsible for poor functional outcome and prolonged stay in the hospital. Investigations have documented that nutrition interventions can enhance the recovery of neurocognitive function in individuals with ischemic stroke. Experimental studies have shown that protein synthesis is suppressed in the ischemic penumbra. In clinical studies on rehabilitation patients designed to study the effects of counteracting or limiting this reduction of protein synthesis by providing protein supplementation, patients receiving such supplementation had enhanced recovery of neurocognitive function. Cellular damage in cerebral ischemia is also partly caused by oxidative damage secondary to free radical formation and lipid peroxidation. Increased oxidative stress negatively affects a patient's life and functional prognosis. Some studies have documented that nutrition supplementation with B-group vitamins may mitigate oxidative damage after acute ischemic stroke. Experimental investigations have also shown that cerebral ischemia changes synaptic zinc release and that acute ischemia increases zinc release, aggravating neuronal injury. In clinical practice, patients with ischemic stroke were found to have a lower than recommended dietary intake of zinc. Patients in whom daily zinc intake was normalized had better recovery of neurological deficits than subjects given a placebo. The aim of this review is to highlight those brain metabolic alterations susceptible to nutrition correction in clinical practice. The mechanisms underlying the relationship between cerebral ischemia and nutrition metabolic conditions are discussed.

Chronic dietary toxicity of zinc oxide nanoparticles in common carp (Cyprinus carpio L.): Tissue accumulation and physiological responses.

PubMed

Chupani, Latifeh; Niksirat, Hamid; Velíšek, Josef; Stará, Alžběta; Hradilová, Šárka; Kolařík, Jan; Panáček, Aleš; Zusková, Eliška

2018-01-01

Concerns regarding the potential toxic effects of zinc oxide nanoparticles (ZnO NPs) on aquatic organisms are growing due to the fact that NPs may be released into aquatic ecosystems. This study aimed to investigate the effects of dietary exposure to ZnO NPs on juvenile common carp (Cyprinus carpio). Fish were fed a spiked diets at doses 50 and 500mg of ZnO NPs per kg of feed for 6 weeks followed by a 2-week recovery period. Fish were sampled every 2 weeks for haematology trends, blood biochemistry measures, histology analyses, and determination of the accumulation of zinc in tissues. At the end of the exposure and post-exposure periods, fish were sampled for an assessment of lipid peroxidation levels. Dietborne ZnO NPs had no effects on haematology, blood biochemistry, and lipid peroxidation levels during the exposure period. After the recovery period, aspartate aminotransferase activity significantly (p < 0.05) increased and alanine transferase activity significantly (p < 0.05) decreased in the higher exposure group. The level of lipid peroxidation significantly (p < 0.05) decreased in liver of treated fish after 2 weeks post-exposure period. A histological examination revealed mild histopathological changes in kidneys during exposure. Our results did not show a significant increase of zinc content at the end of experiment in any of tested organs. However, chronic dietary exposure to ZnO NPs might affect kidney and liver function. Copyright © 2017 Elsevier Inc. All rights reserved.

Outbreak of acute colitis on a horse farm associated with tetracycline-contaminated sweet feed.

PubMed Central

Keir, A A; Stämpfli, H R; Crawford, J

1999-01-01

Exposure of a group of horses to tetracycline-contaminated feed resulted in acute colitis and subsequent death in one horse and milder diarrhea in 3 others. The most severely affected animal demonstrated clinical and pathological findings typical of colitis X. The other herdmates responded well to administration of zinc bacitracin. PMID:10572668

Reactive Transport Modeling Of Remedial Scenarios To Predict Cadmium, Copper, And Zinc In North Fork of Clear Creek, Colorado

EPA Science Inventory

The North Fork of Clear Creek (NFCC), Colorado is an acid-mine-drainage-impacted stream typical of many mountain surface waters affected by historic metal mining in the western United States. The stream is devoid of fish primarily because of high metal concentrations in the wate...

Surface-Water Hydrology and Quality at the Pike Hill Superfund Site, Corinth, Vermont, October 2004 to December 2005

USGS Publications Warehouse

Kiah, Richard G.; Deacon, Jeffrey R.; Piatak, Nadine M.; Seal, Robert R.; Coles, James F.; Hammarstrom, Jane M.

2007-01-01

The hydrology and quality of surface water in and around the Pike Hill Brook watershed, in Corinth, Vermont, was studied from October 2004 to December 2005 by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency (USEPA). Pike Hill was mined intermittently for copper from 1847 to 1919 and the site is known to be contributing trace elements and acidity to Pike Hill Brook and an unnamed tributary to Cookville Brook. The site has been listed as a Superfund site since 2004. Streamflow, specific conductance, pH, and water temperature were measured continuously and monthly at three sites on Pike Hill Brook to determine the variation in these parameters over an annual cycle. Synoptic water-quality sampling was done at 10 stream sites in October 2004, April 2005, and June 2005 and at 13 stream sites in August 2005 to characterize the quality of surface water in the watershed on a seasonal and spatial basis, as well as to assess the effects of wetlands on water quality. Samples for analysis of benthic macroinvertebrate populations were collected at 11 stream sites in August 2005. Water samples were analyzed for 5 major ions and 32 trace elements. Concentrations of trace elements at sites in the Pike Hill Brook watershed exceeded USEPA National Recommended Water Quality Criteria acute and chronic toxicity standards for aluminum, iron, cadmium, copper, and zinc. Concentrations of copper exceeded the chronic criteria in an unnamed tributary to Cookville Brook in one sample. Concentrations of sulfate, calcium, aluminum, iron, cadmium, copper, and zinc decreased with distance from a site directly downstream from the mine (site 1), as a result of dilution and through sorption and precipitation of the trace elements. Maximum concentrations of aluminum, iron, cadmium, copper, and zinc were observed during spring snowmelt. Concentrations of sulfate, calcium, cadmium, copper, and zinc, and instantaneous loads of calcium and aluminum were statistically different (p<0.05) among the three continuously monitored sites (sites 1, 4, and 5). Instantaneous loads of aluminum, iron, and copper decreased by one to three orders of magnitude from site 1 to a site 1.1 mi downstream (site 4). Instantaneous loads of sulfate were similar between sites 1, 4, and at a site 3 mi downstream (site 5). Instantaneous loads of cadmium and zinc were similar between sites 1 and 4, and loads of iron and copper were similar between sites 4 and 5. Loads of chemical constituents were compared at site 1 (closest to the mine waste piles) and site 5 (near the mouth of Pike Hill Brook and below a majority of the wetlands). Annually, the loads of dissolved cadmium and zinc at site 1 were about five times greater than loads at site 5, and the load of dissolved copper at site 1 was about 17 times greater than at site 5. The ratio of loads for dissolved cadmium, copper, and zinc to total cadmium, copper, and zinc at site 1 was about 1. Samples collected in Pike Hill Brook upstream and downstream from the wetlands during low flows in August 2005 showed that oxidation of ferrous iron and precipitation of iron-hydroxides were probably not affecting trace metals in the wetlands through sorption; however, a significant portion of the iron entering the wetlands was in particulate form and may have transported sorbed copper and other trace metals. Thus, aerobic activity in the wetlands was probably not affecting metal cycling in the watershed. Concentrations and loads of sulfate may be unlikely to define unequivocally the role of the wetlands with regard to anaerobic bacterial sulfate reduction; however, bacterial sulfate removal may have affected loads of sulfate. Loads of copper increased downstream from the wetlands and may reflect the reductive dissolution of ferric hydroxide particulates in anaerobic parts of the wetlands.Concentrations of dissolved iron increased downstream from the wetlands. The most apparent effects on the macroinvertebr

ttm-1 Encodes CDF Transporters That Excrete Zinc from Intestinal Cells of C. elegans and Act in a Parallel Negative Feedback Circuit That Promotes Homeostasis

PubMed Central

Roh, Hyun Cheol; Collier, Sara; Deshmukh, Krupa; Guthrie, James; Robertson, J. David; Kornfeld, Kerry

2013-01-01

Zinc is an essential metal involved in a wide range of biological processes, and aberrant zinc metabolism is implicated in human diseases. The gastrointestinal tract of animals is a critical site of zinc metabolism that is responsible for dietary zinc uptake and distribution to the body. However, the role of the gastrointestinal tract in zinc excretion remains unclear. Zinc transporters are key regulators of zinc metabolism that mediate the movement of zinc ions across membranes. Here, we identified a comprehensive list of 14 predicted Cation Diffusion Facilitator (CDF) family zinc transporters in Caenorhabditis elegans and demonstrated that zinc is excreted from intestinal cells by one of these CDF proteins, TTM-1B. The ttm-1 locus encodes two transcripts, ttm-1a and ttm-1b, that use different transcription start sites. ttm-1b expression was induced by high levels of zinc specifically in intestinal cells, whereas ttm-1a was not induced by zinc. TTM-1B was localized to the apical plasma membrane of intestinal cells, and analyses of loss-of-function mutant animals indicated that TTM-1B promotes zinc excretion into the intestinal lumen. Zinc excretion mediated by TTM-1B contributes to zinc detoxification. These observations indicate that ttm-1 is a component of a negative feedback circuit, since high levels of cytoplasmic zinc increase ttm-1b transcript levels and TTM-1B protein functions to reduce the level of cytoplasmic zinc. We showed that TTM-1 isoforms function in tandem with CDF-2, which is also induced by high levels of cytoplasmic zinc and reduces cytoplasmic zinc levels by sequestering zinc in lysosome-related organelles. These findings define a parallel negative feedback circuit that promotes zinc homeostasis and advance the understanding of the physiological roles of the gastrointestinal tract in zinc metabolism in animals. PMID:23717214

Galvanizing action: conclusions and next steps for mainstreaming zinc interventions in public health programs.

PubMed

Brown, Kenneth H; Baker, Shawn K

2009-03-01

This paper summarizes the results of the foregoing reviews of the impact of different intervention strategies designed to enhance zinc nutrition, including supplementation, fortification, and dietary diversification or modification. Current evidence indicates a beneficial impact of such interventions on zinc status and zinc-related functional outcomes. Preventive zinc supplementation reduces the incidence of diarrhea and acute lower respiratory tract infection among young children, decreases mortality of children over 12 months of age, and increases growth velocity. Therapeutic zinc supplementation during episodes of diarrhea reduces the duration and severity of illness. Zinc fortification increases zinc intake and total absorbed zinc, and recent studies are beginning to confirm a positive impact of zinc fortification on indicators of population zinc status. To assist with the development of zinc intervention programs, more information is needed on the prevalence of zinc deficiency in different countries, and rigorous evaluations of the effectiveness of large-scale zinc intervention programs should be planned. Recommended steps for scaling up zinc intervention programs, with or without other micronutrients, are described. In summary, there is now clear evidence of the benefit of selected interventions to reduce the risk of zinc deficiency, and a global commitment is urgently needed to conduct systematic assessments of population zinc status and to develop interventions to control zinc deficiency in the context of existing public health and nutrition programs.

[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.

Zinc Regulation of Aminopeptidase B Involved in Neuropeptide Production

PubMed Central

Hwang, Shin-Rong; Hook, Vivian

2009-01-01

Aminopeptidase B (AP-B) is a metallopeptidase that removes basic residues from the N-termini of neuropeptide substrates in secretory vesicles. This study assessed zinc regulation of AP-B activity, since secretory vesicles contain endogenous zinc. AP-B was inhibited by zinc at concentrations typically present in secretory vesicles. Zinc effects were dependent on concentration, incubation time, and the molar ratio of zinc to enzyme. AP-B activity was recovered upon removal of zinc. AP-B with zinc became susceptible to degradation by trypsin, suggesting that zinc alters enzyme conformation. Zinc regulation demonstrates the metallopeptidase property of AP-B. PMID:18571504

Functional studies of Drosophila zinc transporters reveal the mechanism for dietary zinc absorption and regulation

PubMed Central

2013-01-01

Background Zinc is key to the function of many proteins, but the process of dietary zinc absorption is not well clarified. Current knowledge about dietary zinc absorption is fragmented, and mostly derives from incomplete mammalian studies. To gain a comprehensive picture of this process, we systematically characterized all zinc transporters (that is, the Zip and ZnT family members) for their possible roles in dietary zinc absorption in a genetically amenable model organism, Drosophila melanogaster. Results A set of plasma membrane-resident zinc transporters was identified to be responsible for absorbing zinc from the lumen into the enterocyte and the subsequent exit of zinc to the circulation. dZip1 and dZip2, two functionally overlapping zinc importers, are responsible for absorbing zinc from the lumen into the enterocyte. Exit of zinc to the circulation is mediated through another two functionally overlapping zinc exporters, dZnT1, and its homolog CG5130 (dZnT77C). Somewhat surprisingly, it appears that the array of intracellular ZnT proteins, including the Golgi-resident dZnT7, is not directly involved in dietary zinc absorption. By modulating zinc status in different parts of the body, we found that regulation of dietary zinc absorption, in contrast to that of iron, is unresponsive to bodily needs or zinc status outside the gut. The zinc transporters that are involved in dietary zinc absorption, including the importers dZip1 and dZip2, and the exporter dZnT1, are respectively regulated at the RNA and protein levels by zinc in the enterocyte. Conclusions Our study using the model organism Drosophila thus starts to reveal a comprehensive sketch of dietary zinc absorption and its regulatory control, a process that is still incompletely understood in mammalian organisms. The knowledge gained will act as a reference for future mammalian studies, and also enable an appreciation of this important process from an evolutionary perspective. PMID:24063361

Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xi; Zhou, Xixi; Du, Libo

2014-01-15

Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects ofmore » arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger structure.« less

Methods and options in vitro dialyzability; benefits and limitations.

PubMed

Sandberg, Ann-Sofie

2005-11-01

In vitro dialyzability methods involve a two-step digestion process simulating the gastric and intestinal phase, and dialysis through a semi-permeable membrane with a selected molecular weight cut-off. Dialyzable iron/zinc is used as an estimation of available mineral. Final pH adjustment and use of a strict time schedule were found to be critical factors for standardization. In addition the selected cut-off of the dialysis membrane and the method used for iron and zinc determination influence the results. For screening purposes, simple solubility or dialyzability methods seem preferable to the more sophisticated computer-controlled gastrointestinal model. This is likely more valuable in studies of different transit times and sites of dialyzability. In vitro solubility/dialyzability methods correlate in most cases with human absorption studies in ranking iron and zinc availability from different meals. Exceptions may be that effects of milk, certain proteins, tea, and organic acids cannot be predicted. The dialyzability methods exclude iron bound to large molecules, which in some cases is available and include iron bound to small molecules, which is not always available. In vitro experiments based on solubility/dialyzability are tools to understand factors that may affect subsequent mineral absorption.

Production and Characterization of a Ag- and Zn-Doped Glass-Ceramic Material and In Vitro Evaluation of Its Biological Effects

NASA Astrophysics Data System (ADS)

Baghbani, Fatemeh; Moztarzadeh, Fathollah; Mozafari, Masoud; Raz, Majid; Rezvani, Hamideh

2016-08-01

Bioactive glasses in the system SiO2-CaO-Na2O-P2O5-MgO with different amounts of zinc (Zn) and silver (Ag) were synthesized by the sol-gel technique and characterized. The bioactivity was studied during in vitro assays: the ability of hydroxycarbonate apatite (HCA) layer to form on the glass surface was examined after contact with simulated body fluid (SBF). The x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and inductively coupled plasma atomic emission spectrometry (ICP) studies were performed after immersion in vitro assays. Also, the antibacterial and antifungal activities of glass samples against Pseudomonas aeruginosa (ATCC 27853), E. coli (ATCC 25922), and Candida albicans were measured by the halo zone test. Introduction of zinc and silver as the trace elements induces several modifications on the observed phenomena at the glass surface and in SBF solution after immersion of the samples. The chemical durability of the glasses, the formation of the silica-rich layer, and the crystallization of the HCA layer were affected. Samples with the higher content of zinc and silver exhibited an excellent antibacterial/antifungal activity.

Water and sediment study of the Snake River watershed, Colorado, Oct. 9-12, 2001

USGS Publications Warehouse

Fey, D.L.; Church, S.E.; Unruh, D.M.; Bove, D.J.

2002-01-01

The Snake River watershed, located upstream from Dillon Reservoir in the central mountains of Colorado, has been affected by historical base-metal mining. Trout stocked in the Snake River for recreational purposes do not survive through the winter. Sediment cores analyzed by previous investigators from the reservoir revealed elevated concentrations of base metals and mercury. We collected 36 surface water samples (filtered and unfiltered) and 38 streambed-sediment samples from streams in the Snake River watershed. Analyses of the sediment and water samples show that concentrations of several metals exceed aquatic life standards in one or both media. Ribbon maps showing dissolved concentrations of zinc, cadmium, copper, and manganese in water (0.45-micron filtered and corrected for the ameliorating effect of hardness), and copper, cadmium, and zinc in sediment indicate reaches where toxic effects on trout would be expected and stream reaches where toxicity standards for rainbow, brown, and brook trout are exceeded. Instantaneous loads for sulfate, strontium, iron, cadmium, copper, and zinc were calculated from 0.45-micron-filtered water concentrations and discharge measurements were made at each site. Sulfate and strontium behave conservatively, whereas copper, cadmium, and zinc are reactive. The dissolved copper load entering the reservoir is less than 20 percent of the value calculated from some upper reaches; copper is transferred to suspended and or streambed sediment by sorption to iron oxyhydroxides. Higher percentages of zinc and cadmium reach the reservoir in dissolved form; however, load calculations indicate that some of these metals are also precipitated out of solution. The most effective remediation activities should be concentrated on reducing the dissolved loads of zinc, cadmium, and copper in two reaches of lower Peru Creek between the confluence with the Snake River and Cinnamon Gulch. We analyzed all streambed sediment for mercury and selected streambed-sediment and reservoir core samples for lead isotope signatures. Results indicate that the mercury anomaly in the reservoir sediment was not from any known source in the Snake River, Blue River, or Tenmile Creek watersheds. Its source remains an enigma.

Zinc Deficiency Impacts CO2 Assimilation and Disrupts Copper Homeostasis in Chlamydomonas reinhardtii*

PubMed Central

Malasarn, Davin; Kropat, Janette; Hsieh, Scott I.; Finazzi, Giovanni; Casero, David; Loo, Joseph A.; Pellegrini, Matteo; Wollman, Francis-André; Merchant, Sabeeha S.

2013-01-01

Zinc is an essential nutrient because of its role in catalysis and in protein stabilization, but excess zinc is deleterious. We distinguished four nutritional zinc states in the alga Chlamydomonas reinhardtii: toxic, replete, deficient, and limited. Growth is inhibited in zinc-limited and zinc-toxic cells relative to zinc-replete cells, whereas zinc deficiency is visually asymptomatic but distinguished by the accumulation of transcripts encoding ZIP family transporters. To identify targets of zinc deficiency and mechanisms of zinc acclimation, we used RNA-seq to probe zinc nutrition-responsive changes in gene expression. We identified genes encoding zinc-handling components, including ZIP family transporters and candidate chaperones. Additionally, we noted an impact on two other regulatory pathways, the carbon-concentrating mechanism (CCM) and the nutritional copper regulon. Targets of transcription factor Ccm1 and various CAH genes are up-regulated in zinc deficiency, probably due to reduced carbonic anhydrase activity, validated by quantitative proteomics and immunoblot analysis of Cah1, Cah3, and Cah4. Chlamydomonas is therefore not able to grow photoautotrophically in zinc-limiting conditions, but supplementation with 1% CO2 restores growth to wild-type rates, suggesting that the inability to maintain CCM is a major consequence of zinc limitation. The Crr1 regulon responds to copper limitation and is turned on in zinc deficiency, and Crr1 is required for growth in zinc-limiting conditions. Zinc-deficient cells are functionally copper-deficient, although they hyperaccumulate copper up to 50-fold over normal levels. We suggest that zinc-deficient cells sequester copper in a biounavailable form, perhaps to prevent mismetallation of critical zinc sites. PMID:23439652

Genomic analysis, cytokine expression, and microRNA profiling reveal biomarkers of human dietary zinc depletion and homeostasis.

PubMed

Ryu, Moon-Suhn; Langkamp-Henken, Bobbi; Chang, Shou-Mei; Shankar, Meena N; Cousins, Robert J

2011-12-27

Implementation of zinc interventions for subjects suspected of being zinc-deficient is a global need, but is limited due to the absence of reliable biomarkers. To discover molecular signatures of human zinc deficiency, a combination of transcriptome, cytokine, and microRNA analyses was applied to a dietary zinc depletion/repletion protocol with young male human subjects. Concomitant with a decrease in serum zinc concentration, changes in buccal and blood gene transcripts related to zinc homeostasis occurred with zinc depletion. Microarray analyses of whole blood RNA revealed zinc-responsive genes, particularly, those associated with cell cycle regulation and immunity. Responses of potential signature genes of dietary zinc depletion were further assessed by quantitative real-time PCR. The diagnostic properties of specific serum microRNAs for dietary zinc deficiency were identified by acute responses to zinc depletion, which were reversible by subsequent zinc repletion. Depression of immune-stimulated TNFα secretion by blood cells was observed after low zinc consumption and may serve as a functional biomarker. Our findings introduce numerous novel candidate biomarkers for dietary zinc status assessment using a variety of contemporary technologies and which identify changes that occur prior to or with greater sensitivity than the serum zinc concentration which represents the current zinc status assessment marker. In addition, the results of gene network analysis reveal potential clinical outcomes attributable to suboptimal zinc intake including immune function defects and predisposition to cancer. These demonstrate through a controlled depletion/repletion dietary protocol that the illusive zinc biomarker(s) can be identified and applied to assessment and intervention strategies.

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Manganese phosphate (dibasic). Manganese sulfate. Manganous oxide. Zinc Zinc acetate. Zinc carbonate. Zinc chloride. Zinc oxide. Zinc sulfate. ... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper...

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Manganese phosphate (dibasic). Manganese sulfate. Manganous oxide. Zinc Zinc acetate. Zinc carbonate. Zinc chloride. Zinc oxide. Zinc sulfate. ... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper...

Supplemental levels of iron and calcium interfere with repletion of zinc status in zinc-deficient animals.

PubMed

Jayalakshmi, S; Platel, Kalpana

2016-05-18

Negative interactions between minerals interfering with each other's absorption are of concern when iron and calcium supplements are given to pregnant women and children. We have previously reported that supplemental levels of iron and calcium inhibit the bioaccessibility of zinc, and compromise zinc status in rats fed diets with high levels of these two minerals. The present study examined the effect of supplemental levels of iron and calcium on the recovery of zinc status during a zinc repletion period in rats rendered zinc-deficient. Iron and calcium, both individually and in combination, significantly interfered with the recovery of zinc status in zinc deficient rats during repletion with normal levels of zinc in the diet. Rats maintained on diets containing supplemental levels of these two minerals had significantly lower body weight, and the concentration of zinc in serum and organs was significantly lower than in zinc-deficient rats not receiving the supplements. Iron and calcium supplementation also significantly inhibited the activity of zinc-containing enzymes in the serum as well as liver. Both iron and calcium independently exerted this negative effect on zinc status, while their combination seemed to have a more prominent effect, especially on the activities of zinc containing enzymes. This investigation is probably the first systematic study on the effect of these two minerals on the zinc status of zinc deficient animals and their recovery during repletion with normal amounts of zinc.

Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

PubMed Central

Maret, Wolfgang

2013-01-01

The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

Electrochemical behavior of zinc particles with silica based coatings as anode material for zinc air batteries with improved discharge capacity

NASA Astrophysics Data System (ADS)

Schmid, M.; Willert-Porada, M.

2017-05-01

Silica coatings on zinc particles as anode material for alkaline zinc air batteries are expected to reduce early formation of irreversible ZnO passivation layers during discharge by controlling zinc dissolution and precipitation of supersaturated zincates, Zn(OH)42-. Zinc particles were coated with SiO2 (thickness: 15 nm) by chemical solution deposition and with Zn2SiO4 (thickness: 20 nm) by chemical vapor deposition. These coatings formed a Si(OH)4 gel in aqueous KOH and retarded hydrogen evolution by 40%. By treatment in aqueous KOH and drying afterwards, the silica coatings were changed into ZnO-K2O·SiO2 layers. In this work, the electrochemical performance of such coated zinc particles is investigated by different electrochemical methods in order to gain a deeper understanding of the mechanisms of the coatings, which reduce zinc passivation. In particular, zinc utilization and changes in internal resistance are investigated. Moreover, methods for determination of diffusion coefficients, charge carrier numbers and activation energies for electrochemical oxidation are determined. SiO2-coated zinc particles show improved discharge capacity (CVD-coated zinc: 69% zinc utilization, CSD-coated zinc: 62% zinc utilization) as compared to as-received zinc (57% zinc utilization) at C/20 rate, by reducing supersaturation of zincates. Additionally, KOH-modified SiO2-coated zinc particles enhance rechargeability after 100% depth-of-discharge.

Production of zinc pellets

DOEpatents

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.

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.

Method for the regeneration of spent molten zinc chloride

DOEpatents

Zielke, Clyde W.; Rosenhoover, William A.

1981-01-01

In a process for regenerating spent molten zinc chloride which has been used in the hydrocracking of coal or ash-containing polynuclear aromatic hydrocarbonaceous materials derived therefrom and which contains zinc chloride, zinc oxide, zinc oxide complexes and ash-containing carbonaceous residue, by incinerating the spent molten zinc chloride to vaporize the zinc chloride for subsequent condensation to produce a purified molten zinc chloride: an improvement comprising the use of clay in the incineration zone to suppress the vaporization of metals other than zinc. Optionally water is used in conjunction with the clay to further suppress the vaporization of metals other than zinc.

Influence of structural and surface properties of whey-derived peptides on zinc-chelating capacity, and in vitro gastric stability and bioaccessibility of the zinc-peptide complexes.

PubMed

Udechukwu, M Chinonye; Downey, Brianna; Udenigwe, Chibuike C

2018-02-01

Gastrointestinal stability of zinc-peptide complexes is essential for zinc delivery. As peptide surface charge can influence their metal complex stability, we evaluated the zinc-chelating capacity and stability of zinc complexes of whey protein hydrolysates (WPH), produced with Everlase (WPH-Ever; ζ-potential, -39mV) and papain (WPH-Pap; ζ-potential, -7mV), during simulated digestion. WPH-Ever had lower amount of zinc-binding amino acids but showed higher zinc-chelating capacity than WPH-Pap. This is attributable to the highly anionic surface charge of WPH-Ever for electrostatic interaction with zinc. Release of zinc during peptic digestion was lower for WPH-Ever-zinc, and over 50% of zinc remained bound in both peptide complexes after peptic-pancreatic digestion. Fourier transform infrared spectroscopy suggests the involvement of carboxylate ion, and sidechain carbon-oxygen of aspartate/glutamate and serine/threonine in zinc-peptide complexation. The findings indicate that strong zinc chelation can promote gastric stability and impede intestinal release, for peptides intended for use as dietary zinc carriers. Copyright © 2017 Elsevier Ltd. All rights reserved.

The significance of the source of zinc and its anti-VSC effect.

PubMed

Rölla, G; Jonski, G; Young, A

2002-06-01

The anti-VSC (volatile sulphur compounds) effect of zinc is known to be associated with free zinc ions. To examine whether zinc salts with low stability constants were more suitable as sources of zinc in zinc lozenges than zinc salts with high stability constants. The former provide free zinc ions upon dissolution in water, whereas the latter provide few such ions. Identical lozenges were produced which contained either zinc acetate, zinc gluconate (low stability constants), zinc citrate or amino-acid chelated zinc (extremely high stability constants). All the lozenges contained 0.1 per cent of zinc. A test panel of 10 volunteers used the different lozenges randomly. VSC were measured by GC. The lozenge with the highest stability constant was as effective as those with very low stability constants. The anti-VSC effect was thus not related to this constant. These findings may be explained by the possibility that alternative ligands with stronger affinity for zinc than the original ligands in the lozenges may be present in the oral cavity. An in vitro experiment indicated that the sulphide ion (S2-) may be such a ligand.

Analysis of cellular responses of macrophages to zinc ions and zinc oxide nanoparticles: a combined targeted and proteomic approach.

PubMed

Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Gerdil, Adèle; Diemer, Hélène; Proamer, Fabienne; Collin-Faure, Véronique; Habert, Aurélie; Strub, Jean-Marc; Hanau, Daniel; Herlin, Nathalie; Carrière, Marie; Van Dorsselaer, Alain; Rabilloud, Thierry

2014-06-07

Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate catabolism and proteasome are critical determinants of sensitivity to zinc, which also induces DNA damage. Conversely, glutathione levels and phagocytosis appear unaffected at moderately toxic zinc concentrations.

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)

Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage.

PubMed

Hemilä, Harri

2017-05-01

To compare the efficacy of zinc acetate lozenges with zinc gluconate lozenges in common cold treatment and to examine the dose-dependency of the effect. Meta-analysis. Placebo-controlled zinc lozenge trials, in which the zinc dose was > 75 mg/day. The pooled effect of zinc lozenges on common cold duration was calculated by using inverse-variance random-effects method. Seven randomised trials with 575 participants with naturally acquired common colds. Duration of the common cold. The mean common cold duration was 33% (95% CI 21% to 45%) shorter for the zinc groups of the seven included trials. Three trials that used lozenges composed of zinc acetate found that colds were shortened by 40% and four trials that used zinc gluconate by 28%. The difference between the two salts was not significant: 12 percentage points (95% CI: -12 to + 36). Five trials used zinc doses of 80-92 mg/day, common cold duration was reduced by 33%, and two trials used zinc doses of 192-207 mg/day and found an effect of 35%. The difference between the high-dose and low-dose zinc trials was not significant: 2 percentage points (95% CI: -29 to + 32). Properly composed zinc gluconate lozenges may be as effective as zinc acetate lozenges. There is no evidence that zinc doses over 100 mg/day might lead to greater efficacy in the treatment of the common cold. Common cold patients may be encouraged to try zinc lozenges for treating their colds. The optimal lozenge composition and dosage scheme need to be investigated further.

Multiple Mechanisms of Zinc-Mediated Inhibition for the Apoptotic Caspases-3, -6, -7, and -8.

PubMed

Eron, Scott J; MacPherson, Derek J; Dagbay, Kevin B; Hardy, Jeanne A

2018-05-18

Zinc is emerging as a widely used and important biological regulatory signal. Cellular zinc levels are tightly regulated by a complex array of zinc importers and exporters to control processes such as apoptotic cell death. While caspase inhibition by zinc has been reported previously, the reported inhibition constants were too weak to suggest a critical biological role for zinc-mediated inhibition. In this work, we have adopted a method of assessing available zinc. This allowed assessment of accurate inhibition constants for apoptotic caspases, caspase-3, -6, -7, and -8. Each of these caspases are inhibited by zinc at intracellular levels but with widely differing inhibition constants and different zinc binding stoichiometries. Caspase-3, -6, and -8 appear to be constitutively inhibited by typical zinc levels, and this inhibition must be lifted to allow activation. The inhibition constant for caspase-7 (76 nM) is much weaker than for the other apoptotic caspases (2.6-6.9 nM) suggesting that caspase-7 is not inactivated by normal zinc concentrations but can be inhibited under conditions of zinc stress. Caspase-3, -7, and -8 were found to bind three, one, and two zincs, respectively. In each of these caspases, zinc was present in the active site, in contrast to caspase-6, which binds one zinc allosterically. The most notable new mechanism to emerge from this work is for zinc-mediated inhibition of caspase-8. Zinc binds caspase-8 directly at the active site and at a second site. Zinc binding inhibits formation of the caspase-8 dimer, the activated form of the enzyme. Together these findings suggest that zinc plays a critical role in regulation of apoptosis by direct inactivation of caspases, in a manner that is unique for each caspase.

Prevention of upper aerodigestive tract cancer in zinc-deficient rodents: Inefficacy of genetic or pharmacological disruption of COX-2

PubMed Central

Fong, Louise Y.Y.; Jiang, Yubao; Riley, Maurisa; Liu, Xianglan; Smalley, Karl J.; Guttridge, Denis C.; Farber, John L.

2009-01-01

Zinc deficiency in humans is associated with an increased risk of upper aerodigestive tract (UADT) cancer. In rodents, zinc deficiency predisposes to carcinogenesis by causing proliferation and alterations in gene expression. We examined whether in zinc-deficient rodents, targeted disruption of the cyclooxygenase (COX)-2 pathway by the COX-2 selective inhibitor celecoxib or by genetic deletion prevent UADT carcinogenesis. Tongue cancer prevention studies were conducted in zinc-deficient rats previously exposed to a tongue carcinogen by celecoxib treatment with or without zinc replenishment, or by zinc replenishment alone. The ability of genetic COX-2 deletion to protect against chemically-induced for-estomach tumorigenesis was examined in mice on zinc-deficient versus zinc-sufficient diet. The expression of 3 predictive bio-markers COX-2, nuclear factor (NF)-κ B p65 and leukotriene A4 hydrolase (LTA4H) was examined by immunohistochemistry. In zinc-deficient rats, celecoxib without zinc replenishment reduced lingual tumor multiplicity but not progression to malignancy. Celecoxib with zinc replenishment or zinc replenishment alone significantly lowered lingual squamous cell carcinoma incidence, as well as tumor multiplicity. Celecoxib alone reduced overexpression of the 3 biomarkers in tumors slightly, compared with intervention with zinc replenishment. Instead of being protected, zinc-deficient COX-2 null mice developed significantly greater tumor multiplicity and forestomach carcinoma incidence than wild-type controls. Additionally, zinc-deficient COX-2−/− forestomachs displayed strong LTA4H immunostaining, indicating activation of an alter-native pathway under zinc deficiency when the COX-2 pathway is blocked. Thus, targeting only the COX-2 pathway in zinc-deficient animals did not prevent UADT carcinogenesis. Our data suggest zinc supplementation should be more thoroughly explored in human prevention clinical trials for UADT cancer. PMID:17985342

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

Zinc pharmacokinetic parameters in the determination of body zinc status in children.

PubMed

Vale, S H L; Leite, L D; Alves, C X; Dantas, M M G; Costa, J B S; Marchini, J S; França, M C; Brandão-Neto, J

2014-02-01

Serum or tissue zinc concentrations are often used to assess body zinc status. However, all of these methods are relatively inaccurate. Thus, we investigated three different kinetic methods for the determination of zinc clearance to establish which of these could detect small changes in the body zinc status of children. Forty apparently healthy children were studied. Renal handling of zinc was investigated during intravenous zinc administration (0.06537 mg Zn/kg of body weight), both before and after oral zinc supplementation (5 mg Zn/day for 3 months). Three kinetic methods were used to determine zinc clearance: CZn-Formula A and CZn-Formula B were both used to calculate systemic clearance; the first is a general formula and the second is used for the specific analysis of a single-compartment model; CZn-Formula C is widely used in medical practices to analyze kinetic routine. Basal serum zinc values, which were within the reference range for healthy children, increased significantly after oral zinc supplementation. The three formulas used gave different results for zinc clearance both before and after oral zinc supplementation. CZn-Formula B showed a positive correlation with basal serum zinc concentration after oral supplementation (R2=0.1172, P=0.0306). In addition, CZn-Formula B (P=0.0002) was more effective than CZn-Formula A (P=0.6028) and CZn-Formula C (P=0.0732) in detecting small variations in body zinc status. All three of the formulas used are suitable for studying zinc kinetics; however, CZn-Formula B is particularly effective at detecting small changes in body zinc status in healthy children.

Method of capturing or trapping zinc using zinc getter materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunyadi Murph, Simona E.; Korinko, Paul S.

2017-07-11

A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

Serum thymulin in human zinc deficiency.

PubMed Central

Prasad, A S; Meftah, S; Abdallah, J; Kaplan, J; Brewer, G J; Bach, J F; Dardenne, M

1988-01-01

The activity of thymulin (a thymic hormone) is dependent on the presence of zinc in the molecule. We assayed serum thymulin activity in three models of mildly zinc-deficient (ZD) human subjects before and after zinc supplementation: (a) two human volunteers in whom a specific and mild zinc deficiency was induced by dietary means; (b) six mildly ZD adult sickle cell anemia (SCA) subjects; and (c) six mildly ZD adult non-SCA subjects. Their plasma zinc levels were normal and they showed no overt clinical manifestations of zinc deficiency. The diagnosis of mild zinc deficiency was based on the assay of zinc in lymphocytes, granulocytes, and platelets. Serum thymulin activity was decreased as a result of mild zinc deficiency and was corrected by in vivo and in vitro zinc supplementation, suggesting that this parameter was a sensitive indicator of zinc deficiency in humans. An increase in T101-, sIg-cells, decrease in T4+/T8+ ratio, and decreased IL 2 activity were observed in the experimental human model during the zinc depletion phase, all of which were corrected after repletion with zinc. Similar changes in lymphocyte subpopulation, correctable with zinc supplementation, were also observed in mildly ZD SCA subjects. Inasmuch as thymulin is known to induce intra- and extrathymic T cell differentiation, our studies provide a possible mechanism for the role of zinc on T cell functions. Images PMID:3262625

Identification and Functional Analysis of ZIC3 Mutations in Heterotaxy and Related Congenital Heart Defects

PubMed Central

Ware, Stephanie M.; Peng, Jianlan; Zhu, Lirong; Fernbach, Susan; Colicos, Suzanne; Casey, Brett; Towbin, Jeffrey; Belmont, John W.

2004-01-01

Mutations in the zinc finger transcription factor ZIC3 cause X-linked heterotaxy and have also been identified in patients with isolated congenital heart disease (CHD). To determine the relative contribution of ZIC3 mutations to both heterotaxy and isolated CHD, we screened the coding region of ZIC3 in 194 unrelated patients, including 61 patients with classic heterotaxy, 93 patients with heart defects characteristic of heterotaxy, and 11 patients with situs inversus totalis. Five novel ZIC3 mutations in three classic heterotaxy kindreds and two sporadic CHD cases were identified. None of these alleles was found in 97 ethnically matched control samples. On the basis of these analyses, we conclude that the phenotypic spectrum of ZIC3 mutations should be expanded to include affected females and CHD not typical for heterotaxy. This screening of a cohort of patients with sporadic heterotaxy indicates that ZIC3 mutations account for ∼1% of affected individuals. Missense and nonsense mutations were found in the highly conserved zinc finger–binding domain and in the N-terminal protein domain. Functional analysis of all currently known ZIC3 point mutations indicates that mutations in the putative zinc finger DNA binding domain and in the N-terminal domain result in loss of reporter gene transactivation. It is surprising that transfection studies demonstrate aberrant cytoplasmic localization resulting from mutations between amino acids 253–323 of the ZIC3 protein, indicating that the pathogenesis of a subset of ZIC3 mutations results at least in part from failure of appropriate nuclear localization. These results further expand the phenotypic and genotypic spectrum of ZIC3 mutations and provide initial mechanistic insight into their functional consequences. PMID:14681828

Effects of historical lead–zinc mining on riffle-dwelling benthic fish and crayfish in the Big River of southeastern Missouri, USA

USGS Publications Warehouse

Allert, A.L.; DiStefano, R.J.; Fairchild, J.F.; Schmitt, C.J.; McKee, M.J.; Girondo, J.A.; Brumbaugh, W.G.; May, T.W.

2013-01-01

The Big River (BGR) drains much of the Old Lead Belt mining district (OLB) in southeastern Missouri, USA, which was historically among the largest producers of lead–zinc (Pb–Zn) ore in the world. We sampled benthic fish and crayfish in riffle habitats at eight sites in the BGR and conducted 56-day in situ exposures to the woodland crayfish (Orconectes hylas) and golden crayfish (Orconectes luteus) in cages at four sites affected to differing degrees by mining. Densities of fish and crayfish, physical habitat and water quality, and the survival and growth of caged crayfish were examined at sites with no known upstream mining activities (i.e., reference sites) and at sites downstream of mining areas (i.e., mining and downstream sites). Lead, zinc, and cadmium were analyzed in surface and pore water, sediment, detritus, fish, crayfish, and other benthic macro-invertebrates. Metals concentrations in all materials analyzed were greater at mining and downstream sites than at reference sites. Ten species of fish and four species of crayfish were collected. Fish and crayfish densities were significantly greater at reference than mining or downstream sites, and densities were greater at downstream than mining sites. Survival of caged crayfish was significantly lower at mining sites than reference sites; downstream sites were not tested. Chronic toxic-unit scores and sediment probable effects quotients indicated significant risk of toxicity to fish and crayfish, and metals concentrations in crayfish were sufficiently high to represent a risk to wildlife at mining and downstream sites. Collectively, the results provided direct evidence that metals associated with historical mining activities in the OLB continue to affect aquatic life in the BGR.

Effect of medium variations (zinc supplementation during oocyte maturation, perifertilization pH, and embryo culture protein source) on equine embryo development after intracytoplasmic sperm injection.

PubMed

Choi, Young-Ho; Gibbons, John R; Canesin, Heloísa S; Hinrichs, Katrin

2016-10-15

Prospective studies were conducted to help define procedural factors affecting in vitro embryo production via intracytoplasmic sperm injection (ICSI) of equine oocytes. In experiment 1, use of 10% fetal bovine serum as a protein source in embryo culture medium resulted in a higher blastocyst rate than did use of a combination of 3% fetal bovine serum, 3% equine preovulatory follicular fluid, and 4% human serum substitute (37% vs. 15%, respectively, P < 0.05). In experiment 2, the effect of zinc supplementation (0, 0.5, 1, or 1.5 μg/mL) during IVM was examined. There were no significant differences in rates of cleavage or blastocyst development (20%-31%). However, the proportion of blastocysts that developed on Day 7 for the added-zinc treatments was significantly higher than that for the control treatment (45% vs. 8%). In experiment 3, we tested whether use of high-pH medium (pH 8.0-8.4) during ICSI procedures would improve blastocyst rate when sperm with low cleavage rates after ICSI was used. When high-pH conditions were used for sperm preparation and also for the first 2 hours of incubation of injected oocytes after ICSI, the cleavage rate was unaffected but no blastocysts developed (0% vs. 24% for control). When high-pH conditions were used for sperm preparation only, the blastocyst rate was 37%. This was repeated using sperm from a second stallion; there was no significant difference in cleavage or blastocyst rates between sperm preparation in high pH vs. control medium. These findings add to our knowledge of factors affecting in vitro production of equine embryos. Copyright © 2016 Elsevier Inc. All rights reserved.

The Zinc Transporter Zip5 (Slc39a5) Regulates Intestinal Zinc Excretion and Protects the Pancreas against Zinc Toxicity

PubMed Central

Geiser, Jim; De Lisle, Robert C.; Andrews, Glen K.

2013-01-01

Background ZIP5 localizes to the baso-lateral membranes of intestinal enterocytes and pancreatic acinar cells and is internalized and degraded coordinately in these cell-types during periods of dietary zinc deficiency. These cell-types are thought to control zinc excretion from the body. The baso-lateral localization and zinc-regulation of ZIP5 in these cells are unique among the 14 members of the Slc39a family and suggest that ZIP5 plays a role in zinc excretion. Methods/Principal Findings We created mice with floxed Zip5 genes and deleted this gene in the entire mouse or specifically in enterocytes or acinar cells and then examined the effects on zinc homeostasis. We found that ZIP5 is not essential for growth and viability but total knockout of ZIP5 led to increased zinc in the liver in mice fed a zinc-adequate (ZnA) diet but impaired accumulation of pancreatic zinc in mice fed a zinc-excess (ZnE) diet. Loss-of-function of enterocyte ZIP5, in contrast, led to increased pancreatic zinc in mice fed a ZnA diet and increased abundance of intestinal Zip4 mRNA. Finally, loss-of-function of acinar cell ZIP5 modestly reduced pancreatic zinc in mice fed a ZnA diet but did not impair zinc uptake as measured by the rapid accumulation of 67zinc. Retention of pancreatic 67zinc was impaired in these mice but the absence of pancreatic ZIP5 sensitized them to zinc-induced pancreatitis and exacerbated the formation of large cytoplasmic vacuoles containing secretory protein in acinar cells. Conclusions These studies demonstrate that ZIP5 participates in the control of zinc excretion in mice. Specifically, they reveal a paramount function of intestinal ZIP5 in zinc excretion but suggest a role for pancreatic ZIP5 in zinc accumulation/retention in acinar cells. ZIP5 functions in acinar cells to protect against zinc-induced acute pancreatitis and attenuate the process of zymophagy. This suggests that it may play a role in autophagy. PMID:24303081

A novel mechanism for the pyruvate protection against zinc-induced cytotoxicity: mediation by the chelating effect of citrate and isocitrate.

PubMed

Sul, Jee-Won; Kim, Tae-Youn; Yoo, Hyun Ju; Kim, Jean; Suh, Young-Ah; Hwang, Jung Jin; Koh, Jae-Young

2016-08-01

Intracellular accumulation of free zinc contributes to neuronal death in brain injuries such as ischemia and epilepsy. Pyruvate, a glucose metabolite, has been shown to block zinc neurotoxicity. However, it is largely unknown how pyruvate shows such a selective and remarkable protective effect. In this study, we sought to find a plausible mechanism of pyruvate protection against zinc toxicity. Pyruvate almost completely blocked cortical neuronal death induced by zinc, yet showed no protective effects against death induced by calcium (ionomycin, NMDA) or ferrous iron. Of the TCA cycle intermediates, citrate, isocitrate, and to a lesser extent oxaloacetate, protected against zinc toxicity. We then noted with LC-MS/MS assay that exposure to pyruvate, and to a lesser degree oxaloacetate, increased levels of citrate and isocitrate, which are known zinc chelators. While pyruvate added only during zinc exposure did not reduce zinc toxicity, citrate and isocitrate added only during zinc exposure, as did extracellular zinc chelator CaEDTA, completely blocked it. Furthermore, addition of pyruvate after zinc exposure substantially reduced intracellular zinc levels. Our results suggest that the remarkable protective effect of pyruvate against zinc cytotoxicity may be mediated indirectly by the accumulation of intracellular citrate and isocitrate, which act as intracellular zinc chelators.

Zinc and Regulation of Inflammatory Cytokines: Implications for Cardiometabolic Disease

PubMed Central

Foster, Meika; Samman, Samir

2012-01-01

In atherosclerosis and diabetes mellitus, the concomitant presence of low-grade systemic inflammation and mild zinc deficiency highlights a role for zinc nutrition in the management of chronic disease. This review aims to evaluate the literature that reports on the interactions of zinc and cytokines. In humans, inflammatory cytokines have been shown both to up- and down-regulate the expression of specific cellular zinc transporters in response to an increased demand for zinc in inflammatory conditions. The acute phase response includes a rapid decline in the plasma zinc concentration as a result of the redistribution of zinc into cellular compartments. Zinc deficiency influences the generation of cytokines, including IL-1β, IL-2, IL-6, and TNF-α, and in response to zinc supplementation plasma cytokines exhibit a dose-dependent response. The mechanism of action may reflect the ability of zinc to either induce or inhibit the activation of NF-κB. Confounders in understanding the zinc-cytokine relationship on the basis of in vitro experimentation include methodological issues such as the cell type and the means of activating cells in culture. Impaired zinc homeostasis and chronic inflammation feature prominently in a number of cardiometabolic diseases. Given the high prevalence of zinc deficiency and chronic disease globally, the interplay of zinc and inflammation warrants further examination. PMID:22852057

Proposed industrial recovered materials utilization targets for the metals and metal products industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1979-05-01

Set targets for increased utilization of energy-saving recovered materials in the metals and metal products industries (ferrous, aluminium, copper, zinc, and lead) are discussed. Data preparation and methodology development and analysis of the technological and economic factors in order to prepare draft targets for the use of recovered materials are covered. Chapter 2 provides an introductory discussion of the factors that affect the recovery and reuse of secondary materials and the competition between the primary and secondary metals industries. Chapter 3 presents general profiles for the major industrial segments comprising SIC 33, including industry structure, process technology, materials and recyclingmore » flow, and future trends for the 5 industries: ferrous, aluminium, copper, zinc, and lead. Chapter 4 presents the evaluation of recycling targets for those industries. (MCW)« less

Biokinetics of zinc oxide nanoparticles: toxicokinetics, biological fates, and protein interaction

PubMed Central

Choi, Soo-Jin; Choy, Jin-Ho

2014-01-01

Biokinetic studies of zinc oxide (ZnO) nanoparticles involve systematic and quantitative analyses of absorption, distribution, metabolism, and excretion in plasma and tissues of whole animals after exposure. A full understanding of the biokinetics provides basic information about nanoparticle entry into systemic circulation, target organs of accumulation and toxicity, and elimination time, which is important for predicting the long-term toxic potential of nanoparticles. Biokinetic behaviors can be dependent on physicochemical properties, dissolution property in biological fluids, and nanoparticle–protein interaction. Moreover, the determination of biological fates of ZnO nanoparticles in the systemic circulation and tissues is critical in interpreting biokinetic behaviors and predicting toxicity potential as well as mechanism. This review focuses on physicochemical factors affecting the biokinetics of ZnO nanoparticles, in concert with understanding bioavailable fates and their interaction with proteins. PMID:25565844

Trace-elements in sheep grazing near a lead-zinc smelting complex at Port Pirie, South Australia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koh, T.S.; Judson, G.J.

1986-07-01

In South Australia, several studies have shown that heavy metal pollution of soils and plants occurs in the vicinity of a lead/zinc smelter at Port Pirie. Data on soil analysis indicates that at least 3400 km/sup 2/ of land near these smelters has been contaminated by the fallout of Pb, Zn and Cd. It is possible that contamination of soil and pasture by heavy metals may adversely affect the health of livestock grazing near the smelters. In sheep, Pb toxicity causes anorexia, abdominal pain and diarrhea while Zn or Cd supplementation reduces the Cu status. This study was undertaken tomore » investigate the effects of heavy metals on the trace-element status of sheep grazing at selected distances from the Port Pirie smelters.« less

A combined intervention of zinc, multiple micronutrients, and albendazole does not ameliorate environmental enteric dysfunction or stunting in rural Malawian children in a double-blind randomized controlled trial

USDA-ARS?s Scientific Manuscript database

Environmental enteric dysfunction (EED) and linear growth stunting affect many rural agrarian children in the developing world and contribute to the persistently high rates of stunting that are observed worldwide. Effective interventions to consistently ameliorate EED are lacking. We tested whether ...

Transcription factor ZBED6 mediates IGF2 gene expression by regulating promoter activity and DNA methylation in myoblasts

USDA-ARS?s Scientific Manuscript database

Zinc finger, BED-type containing 6 (ZBED6) is an important transcription factor in placental mammals, affecting development, cell proliferation and growth. In this study, we found that the expression of the ZBED6 and IGF2 were up regulated during C2C12 differentiation. The IGF2 expression levels wer...

SIMS depth profiling of rubber-tyre cord bonding layers prepared using 64Zn depleted ZnO

NASA Astrophysics Data System (ADS)

Fulton, W. S.; Sykes, D. E.; Smith, G. C.

2006-07-01

Zinc oxide and copper/zinc sulphide layers are formed during vulcanisation and moulding of rubber to brass-coated steel tyre reinforcing cords. Previous studies have described how zinc diffuses through the rubber-brass interface to form zinc sulphide, and combines with oxygen to create zinc oxide during dezincification. The zinc is usually assumed to originate in the brass of the tyre cord, however, zinc oxide is also present in the rubber formulation. We reveal how zinc from these sources is distributed within the interfacial bonding layers, before and after heat and humidity ageing. Zinc oxide produced using 64Zn-isotope depleted zinc was mixed in the rubber formulation in place of the natural ZnO and the zinc isotope ratios within the interfacial layers were followed by secondary ion mass spectroscopy (SIMS) depth profiling. Variations in the relative ratios of the zinc isotopes during depth profiling were measured for unaged, heat-aged and humidity-aged wire samples and in each case a relatively large proportion of the zinc incorporated into the interfacial layer as zinc sulphide was shown to have originated from ZnO in the rubber compound.

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

Critical Role of Zinc as Either an Antioxidant or a Prooxidant in Cellular Systems

PubMed Central

2018-01-01

Zinc is recognized as an essential trace metal required for human health; its deficiency is strongly associated with neuronal and immune system defects. Although zinc is a redox-inert metal, it functions as an antioxidant through the catalytic action of copper/zinc-superoxide dismutase, stabilization of membrane structure, protection of the protein sulfhydryl groups, and upregulation of the expression of metallothionein, which possesses a metal-binding capacity and also exhibits antioxidant functions. In addition, zinc suppresses anti-inflammatory responses that would otherwise augment oxidative stress. The actions of zinc are not straightforward owing to its numerous roles in biological systems. It has been shown that zinc deficiency and zinc excess cause cellular oxidative stress. To gain insights into the dual action of zinc, as either an antioxidant or a prooxidant, and the conditions under which each role is performed, the oxidative stresses that occur in zinc deficiency and zinc overload in conjunction with the intracellular regulation of free zinc are summarized. Additionally, the regulatory role of zinc in mitochondrial homeostasis and its impact on oxidative stress are briefly addressed. PMID:29743987

Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

NASA Astrophysics Data System (ADS)

Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

2016-10-01

With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

Enhancement of hippocampal mossy fiber activity in zinc deficiency and its influence on behavior.

PubMed

Takeda, Atsushi; Itoh, Hiromasa; Yamada, Kohei; Tamano, Haruna; Oku, Naoto

2008-10-01

The extracellular concentration of glutamate in the hippocampus is increased by hippocampal perfusion with CaEDTA, a membrane-impermeable zinc chelator, suggesting that the activity of glutamatergic neurons in the hippocampus are influenced by the extracellular concentrations of zinc. In the present study, the relationship between the extracellular concentrations of zinc and mossy fiber activity in the hippocampus was examined in mice and rats fed a zinc-deficient diet for 4 weeks. Timm's stain, by which histochemically reactive zinc in the presynaptic vesicles is detected, was attenuated in the hippocampus in zinc deficiency. The extracellular signal of ZnAF-2, a membrane-impermeable zinc indicator, was also lower in the hippocampal CA3, suggesting that the basal extracellular concentrations of zinc are lower maintained in zinc deficiency. To check mossy fiber activity after 4-week zinc deprivation, the decrease in the signal of FM4-64, an indicator of presynaptic activity (exocytosis), at mossy fiber synapses was measured under the condition of spontaneous depolarization. The decrease was significantly facilitated by zinc deficiency, suggesting that the basal exocytosis at mossy fiber synapses is enhanced by zinc deficiency. On the other hand, the increase in anxiety-like behavior was observed in the open-field test after 4-week zinc deprivation. The present study demonstrates that the decrease in the basal extracellular concentrations of zinc may be linked to the enhancement of the basal mossy fiber activity in zinc deficiency. This decrease seems to be also involved in neuropsychological behavior in zinc deficiency.

Adverse effects of parental zinc deficiency on metal homeostasis and embryonic development in a zebrafish model.

PubMed

Beaver, Laura M; Nkrumah-Elie, Yasmeen M; Truong, Lisa; Barton, Carrie L; Knecht, Andrea L; Gonnerman, Greg D; Wong, Carmen P; Tanguay, Robert L; Ho, Emily

2017-05-01

The high prevalence of zinc deficiency is a global public health concern, and suboptimal maternal zinc consumption has been associated with adverse effects ranging from impaired glucose tolerance to low birthweights. The mechanisms that contribute to altered development and poor health in zinc deficient offspring are not completely understood. To address this gap, we utilized the Danio rerio model and investigated the impact of dietary zinc deficiency on adults and their developing progeny. Zinc deficient adult fish were significantly smaller in size, and had decreases in learning and fitness. We hypothesized that parental zinc deficiency would have an impact on their offspring's mineral homeostasis and embryonic development. Results from mineral analysis showed that parental zinc deficiency caused their progeny to be zinc deficient. Furthermore, parental dietary zinc deficiency had adverse consequences for their offspring including a significant increase in mortality and decreased physical activity. Zinc deficient embryos had altered expression of genes that regulate metal homeostasis including several zinc transporters (ZnT8, ZnT9) and the metal-regulatory transcription factor 1 (MTF-1). Zinc deficiency was also associated with decreased expression of genes related to diabetes and pancreatic development in the embryo (Insa, Pax4, Pdx1). Decreased expression of DNA methyltransferases (Dnmt4, Dnmt6) was also found in zinc deficient offspring, which suggests that zinc deficiency in parents may cause altered epigenetic profiles for their progeny. These data should inform future studies regarding zinc deficiency and pregnancy and suggest that supplementation of zinc deficient mothers prior to pregnancy may be beneficial. Published by Elsevier Inc.

Multi-modular, tris(triphenylamine) zinc porphyrin-zinc phthalocyanine-fullerene conjugate as a broadband capturing, charge stabilizing, photosynthetic 'antenna-reaction center' mimic.

PubMed

Kc, Chandra B; Lim, Gary N; D'Souza, Francis

2015-04-21

A broadband capturing, charge stabilizing, photosynthetic antenna-reaction center model compound has been newly synthesized and characterized. The model compound is comprised of a zinc porphyrin covalently linked to three units of triphenylamine entities and a zinc phthalocyanine entity. The absorption and fluorescence spectra of zinc porphyrin complemented that of zinc phthalocyanine offering broadband coverage. Stepwise energy transfer from singlet excited triphenylamine to zinc porphyrin, and singlet excited zinc porphyrin to zinc phthalocyanine (kENT ∼ 10(11) s(-1)) was established from spectroscopic and time-resolved transient absorption techniques. Next, an electron acceptor, fullerene was introduced via metal-ligand axial coordination to both zinc porphyrin and zinc phthalocyanine centers, and they were characterized by spectroscopic and electrochemical techniques. An association constant of 4.9 × 10(4) M(-1) for phenylimidazole functionalized fullerene binding to zinc porphyrin, and 5.1 × 10(4) M(-1) for it binding to zinc phthalocyanine was obtained. An energy level diagram for the occurrence of different photochemical events within the multi-modular donor-acceptor conjugate was established from spectral and electrochemical data. Unlike the previous zinc porphyrin-zinc phthalocyanine-fullerene conjugates, the newly assembled donor-acceptor conjugate has been shown to undergo the much anticipated initial charge separation from singlet excited zinc porphyrin to the coordinated fullerene followed by a hole shift process to zinc phthalocyanine resulting in a long-lived charge separated state as revealed by femto- and nanosecond transient absorption spectroscopic techniques. The lifetime of the final charge separated state was about 100 ns.

Adverse effects of parental zinc deficiency on metal homeostasis and embryonic development in a zebrafish model

PubMed Central

Beaver, Laura M.; Nkrumah-Elie, Yasmeen M.; Truong, Lisa; Barton, Carrie L.; Knecht, Andrea L.; Gonnerman, Greg D.; Wong, Carmen P.; Tanguay, Robert L.; Ho, Emily

2017-01-01

The high prevalence of zinc deficiency is a global public health concern, and suboptimal maternal zinc consumption has been associated with adverse effects ranging from impaired glucose tolerance to low birthweights. The mechanisms that contribute to altered development and poor health in zinc deficient offspring are not completely understood. To address this gap, we utilized the Danio rerio model and investigated the impact of dietary zinc deficiency on adults and their developing progeny. Zinc deficient adult fish were significantly smaller in size, and had decreases in learning and fitness. We hypothesized that parental zinc deficiency would have an impact on their offspring’s mineral homeostasis and embryonic development. Results from mineral analysis showed that parental zinc deficiency caused their progeny to be zinc deficient. Furthermore, parental dietary zinc deficiency had adverse consequences for their offspring including a significant increase in mortality and decreased physical activity. Zinc deficient embryos had altered expression of genes that regulate metal homeostasis including several zinc transporters (ZnT8, ZnT9) and the metal-regulatory transcription factor 1 (MTF-1). Zinc deficiency was also associated with decreased expression of genes related to diabetes and pancreatic development in the embryo (Insa, Pax4, Pdx1). Decreased expression of DNA methyltransferases (Dnmt4, Dnmt6) was also found in zinc deficient offspring, which suggests that zinc deficiency in parents may cause altered epigenetic profiles for their progeny. These data should inform future studies regarding zinc deficiency and pregnancy and suggest that supplementation of zinc deficient mothers prior to pregnancy may be beneficial. PMID:28268202

Peptide-based, two-fluorophore, ratiometric probe for quantifying mobile zinc in biological solutions.

PubMed

Zhang, Daniel Y; Azrad, Maria; Demark-Wahnefried, Wendy; Frederickson, Christopher J; Lippard, Stephen J; Radford, Robert J

2015-02-20

Small-molecule fluorescent sensors are versatile agents for detecting mobile zinc in biology. Capitalizing on the abundance of validated mobile zinc probes, we devised a strategy for repurposing existing intensity-based sensors for quantitative applications. Using solid-phase peptide synthesis, we conjugated a zinc-sensitive Zinpyr-1 derivative and a zinc-insensitive 7-hydroxycoumarin derivative onto opposite ends of a rigid P9K peptide scaffold to create HcZ9, a ratiometric fluorescent probe for mobile zinc. A plate reader-based assay using HcZ9 was developed, the accuracy of which is comparable to that of atomic absorption spectroscopy. We investigated zinc accumulation in prostatic cells and zinc levels in human seminal fluid. When normal and tumorigenic cells are bathed in zinc-enriched media, cellular mobile zinc is buffered and changes slightly, but total zinc levels increase significantly. Quantification of mobile and total zinc levels in human seminal plasma revealed that the two are positively correlated with a Pearson's coefficient of 0.73.

Evaluation of a hollow fiber supported liquid membrane device as a chemical surrogate for the measurements of zinc (II) bioavailability using two microalgae strains as biological references.

PubMed

Rodríguez-Morales, Erik A; Rodríguez de San Miguel, Eduardo; de Gyves, Josefina

2017-03-01

The environmental bioavailability of zinc (II), i.e., the uptake of the element by an organism, was determined using two microalgae species, Scenedesmus acutus and Pseudokirchneriella subcapitata, and estimated using hollow fiber supported liquid membrane (HF-SLM) device as the chemical surrogate. Several experimental conditions were studied including the presence of organic matter, inorganic anions and concomitant cations and pH. The results show strong positive correlation coefficients between the responses given by the HF-SLM and the microalgae species (r = 0.900 for S. acutus and r = 0.876 for P. subcapitata) in multivariate environments (changes in pH, calcium, humic and citrate concentrations). The maximum amount of zinc (II) retained by the HF-SLM (4.7 × 10 -8  mol/cm 2 ) was higher than those for P. subcapitata and S. acutus (9.4 × 10 -11  mol/cm 2 and 6.2 × 10 -11  mol/cm 2 , respectively). The variation in pH (pH 5.5-9) was the variable with the greatest effect on zinc internalization in all systems, increasing approximately 2.5 times for P. subcapitata and 5.5 times for S. acutus respect to pH = 5.5, while the presence of humic acids did not affect the response. The species' concentration analysis of the experimental design at pH = 5.5 indicated that the amount of internalized zinc (II) by the HF-SLM and both microalgae species is strongly dependent on the free zinc concentration (r = 0.910 for the HF-SLM, r = 0.922 for S. acutus and r = 0.954 for P. subcapitata); however, at pH = 9.0, the amount of internalized zinc (II) is strongly dependent on the sum of free zinc and labile species (r = 0.912 for the HF-SLM, r = 0.947 for S. acutus and r = 0.900 for P. subcapitata). The presence of inorganic ligands (chloride, sulfate, phosphate, carbonate, and nitrate) and metal ions (cobalt (II), copper (II), nickel (II), chromium (VI), lead (II) and cadmium (II)) produced different behaviors both in the chemical surrogate and the biological references. The results showed that the synthetic device can mimic biological uptake in the presence of humic acids, nitrate, sulfate, and phosphate, and pH within the range 5.5-9 when S. acutus was used as the biological reference, considering the simultaneous contribution of the Zn 2+ and ZnOH + labile species depending on the chemical composition of the medium. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geochemistry of Mine Waste and Mill Tailings, Meadow Deposits, Streambed Sediment, and General Hydrology and Water Quality for the Frohner Meadows Area, Upper Lump Gulch, Jefferson County, Montana

USGS Publications Warehouse

Klein, Terry L.; Cannon, Michael R.; Fey, David L.

2004-01-01

Frohner Meadows, an area of low-topographic gradient subalpine ponds and wetlands in glaciated terrane near the headwaters of Lump Gulch (a tributary of Prickly Pear Creek), is located about 15 miles west of the town of Clancy, Montana, in the Helena National Forest. Mining and ore treatment of lead-zinc-silver veins in granitic rocks of the Boulder batholith over the last 120 years from two sites (Frohner mine and the Nellie Grant mine) has resulted in accumulations of mine waste and mill tailings that have been distributed downslope and downstream by anthropogenic and natural processes. This report presents the results of an investigation of the geochemistry of the wetlands, streams, and unconsolidated-sediment deposits and the hydrology, hydrogeology, and water quality of the area affected by these sources of ore-related metals. Ground water sampled from most shallow wells in the meadow system contained high concentrations of arsenic, exceeding the Montana numeric water-quality standard for human health. Transport of cadmium and zinc in ground water is indicated at one site near Nellie Grant Creek based on water-quality data from one well near the creek. Mill tailings deposited in upper Frohner Meadow contribute large arsenic loads to Frohner Meadows Creek; Nellie Grant Creek contributes large arsenic, cadmium, and zinc loads to upper Frohner Meadows. Concentrations of total-recoverable cadmium, copper, lead, and zinc in most surface-water sites downstream from the Nellie Grant mine area exceeded Montana aquatic-life standards. Nearly all samples of surface water and ground water had neutral to slightly alkaline pH values. Concentrations of arsenic, cadmium, lead, and zinc in streambed sediment in the entire meadow below the mine waste and mill tailings accumulations are highly enriched relative to regional watershed-background concentrations and exceed consensus-based, probable-effects concentrations for streambed sediment at most sites. Cadmium, copper, and zinc typically are adsorbed to the surface coatings of streambed-sediment grains. Mine waste and mill tailings contain high concentrations of arsenic, cadmium, copper, lead, and zinc in a quartz-rich matrix. Most of the waste sites that were sampled had low acid-generating capacity, although one site (fine-grained mill tailings from the Nellie Grant mine deposited in the upper part of lower Frohner Meadows) had extremely high acid-generating potential because of abundant fine-grained pyrite. Two distinct sites were identified as metal sources based on streambed-sediment samples, cores in the meadow substrate, and mine and mill-tailings samples. The Frohner mine and mill site contribute material rich in arsenic and lead; similar material from the Nellie Grant mine and mill site is rich in cadmium and zinc.

Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

USDA-ARS?s Scientific Manuscript database

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

PubMed Central

Wilson, Rebecca L.; Grieger, Jessica A.; Bianco-Miotto, Tina; Roberts, Claire T.

2016-01-01

Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE); spontaneous preterm birth (sPTB); low birthweight (LBW); and gestational diabetes (GDM). Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g) and those who gave birth to an infant of adequate weight (>2500 g), particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg). No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status. PMID:27754451

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. Copyright © 2013 S. Karger AG, Basel.

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.

The Role of Compost in Stabilizing the Microbiological and Biochemical Properties of Zinc-Stressed Soil.

PubMed

Strachel, Rafał; Wyszkowska, Jadwiga; Baćmaga, Małgorzata

2017-01-01

The progressive development of civilization and intensive industrialization has contributed to the global pollution of the natural environment by heavy metals, especially the soil. Degraded soils generally contain less organic matter, and thus, their homeostasis is more often disturbed, which in turn manifests in changes in biological and physicochemical properties of the soil. Therefore, new possibilities and solutions for possible neutralization of these contaminations are sought, inter alia, through reclamation of degraded land. At present, the use of additives supporting the reclamation process that exhibit heavy metal-sorbing properties is becoming increasingly important in soil recovery. Research was conducted to determine the role of compost in stabilizing the microbial and biochemical balance of the soil due to the significant problem of heavy metal-contaminated areas. The study was conducted on loamy sand, to which zinc was applied at the following doses: 0, 250, 500, 750, 1000, and 1250 mg Zn 2+  kg -1 DM of soil. Compost was introduced to the appropriate objects calculated on the basis of organic carbon content in the amount of 0, 10, and 20 g C org  kg -1 DM of soil. The study was conducted over a period of 20 weeks, maintaining soil moisture at 50% capillary water capacity. Zinc significantly modified soil microbiome status. The abundance of microorganisms and their biological diversity and the enzymatic activity of the soil were affected. The negative effects of contaminating zinc doses were alleviated by the introduction of compost into the soil. Organic fertilization led to microbial growth intensification and increased biochemical activity of the soil already 2 weeks after compost application. These effects persisted throughout the experiment. Therefore, it can be stated that the use of compost is an appropriate method for restoring normal functions of soil ecosystems contaminated with zinc.

Using ICP and micro-PIXE to investigate possible differences in the mineral composition of genetically modified versus wild-type sorghum grain

NASA Astrophysics Data System (ADS)

Ndimba, R.; Cloete, K.; Mehlo, L.; Kossmann, J.; Mtshali, C.; Pineda-Vargas, C.

2017-08-01

In the present study, possible differences in the mineral composition of transgenic versus non-transgenic sorghum grains were investigated using inductively coupled atomic emission spectroscopy (ICP-AES); and, in-tissue elemental mapping by micro Proton-Induced X-ray Emission (micro-PIXE) analysis. ICP AES was used to analyse the bulk mineral content of the wholegrain flour derived from each genotype; whilst micro-PIXE was used to interrogate localised differences in mineral composition specific to certain areas of the grain, such as the bran layer and the central endosperm tissue. According to the results obtained, no significant difference in the average Fe, Zn or Ca content was found to differentiate the transgenic from the wild-type grain using ICP-AES. However, using micro-PIXE, a significant reduction in zinc could be detected in the bran layer of the transgenic grains relative to wild-type. Although it is difficult to draw firm conclusions, as a result of the small sample size used in this study, micro-PIXE has nonetheless proven itself as a useful technique for highlighting the possibility that there may be reduced levels of zinc accumulation in the bran layer of the transgenic grains. Given that the genetic modification targets proteins that are highly concentrated in certain parts of the bran tissue, it seems plausible that the reduced levels of zinc may be an unintended consequence of the silencing of kafirin proteins. Although no immediate health or nutritional concerns emerge from this preliminary finding, it is noted that zinc plays an important biological role within this part of the grain as a structural stabiliser and antioxidant factor. Further study is therefore needed to assess more definitively the extent of the apparent localised reduction in zinc in the transgenic grains and how this may affect other important grain quality characteristics.

Relationships between serum selenium and zinc concentrations versus profibrotic and proangiogenic cytokines (FGF-19 and endoglin) in patients with alcoholic liver cirrhosis.

PubMed

Prystupa, Andrzej; Kiciński, Paweł; Luchowska-Kocot, Dorota; Błażewicz, Anna; Kurys-Denis, Ewa; Niedziałek, Jarosław; Sak, Jarosław; Panasiuk, Lech

2017-09-21

Liver cirrhosis is a disease involving the liver parenchyma, which is characterised by fibrosis and impaired architectonics of the parenchyma with regenerative nodules. The aim of the study was to determine the relationship between stage of alcoholic liver cirrhosis, concentrations of selenium, zinc and profibrotic and proangiogenic cytokines (FGF-19, ENG). The study included 99 patients with alcoholic cirrhosis and 20 healthy subjects. Ion chromatography with UV/VIS detection was used for determination of zinc ions in the previously mineralized serum samples. The measurements of selenium were performed with the ContrAA700 high-resolution continuum source graphite tube atomic absorption spectrometer. ELISA was used to determine concentration of FGF-19 and ENG in serum samples. Concentrations of zinc and selenium were significantly decreased in cirrhotic patients (p<0.001 for both). The highest concentration of FGF-19 was found in Child-Pugh stage C liver cirrhosis patients (806.9±650.3 pg/ml), and was significantly higher than observed in controls (p=0.005) and stage A patients (compensated cirrhosis) (p=0.02). The highest concentration of ENG was demonstrated in the control group (3.24±148 ng/ml) while the lowest in patients with decompensated cirrhosis (7.32±5.39 ng/ml and 7.92±4.18 ng/ml for stage B and C; p=0.03 and p=0.02, respectively). The use of the multiple-variable model demonstrated that the independent factors affecting the concentration of ENG were the concentration of bilirubin (p=0.02), INR (p=0.01) and duration of alcohol abuse (p=0.02). The independent determinants of FGF-19 concentrations were found to be the stage (severity) of liver cirrhosis (p=0.04) and INR (p=0.03). Concentrations of zinc and selenium in serum of patients with alcoholic liver cirrhosis are not independently related to concentrations of FGF-19 and ENG.

Zinc and Copper Differentially Modulate Amyloid Precursor Protein Processing by γ-Secretase and Amyloid-β Peptide Production.

PubMed

Gerber, Hermeto; Wu, Fang; Dimitrov, Mitko; Garcia Osuna, Guillermo M; Fraering, Patrick C

2017-03-03

Recent evidence suggests involvement of biometal homeostasis in the pathological mechanisms in Alzheimer's disease (AD). For example, increased intracellular copper or zinc has been linked to a reduction in secreted levels of the AD-causing amyloid-β peptide (Aβ). However, little is known about whether these biometals modulate the generation of Aβ. In the present study we demonstrate in both cell-free and cell-based assays that zinc and copper regulate Aβ production by distinct molecular mechanisms affecting the processing by γ-secretase of its Aβ precursor protein substrate APP-C99. We found that Zn 2+ induces APP-C99 dimerization, which prevents its cleavage by γ-secretase and Aβ production, with an IC 50 value of 15 μm Importantly, at this concentration, Zn 2+ also drastically raised the production of the aggregation-prone Aβ43 found in the senile plaques of AD brains and elevated the Aβ43:Aβ40 ratio, a promising biomarker for neurotoxicity and AD. We further demonstrate that the APP-C99 histidine residues His-6, His-13, and His-14 control the Zn 2+ -dependent APP-C99 dimerization and inhibition of Aβ production, whereas the increased Aβ43:Aβ40 ratio is substrate dimerization-independent and involves the known Zn 2+ binding lysine Lys-28 residue that orientates the APP-C99 transmembrane domain within the lipid bilayer. Unlike zinc, copper inhibited Aβ production by directly targeting the subunits presenilin and nicastrin in the γ-secretase complex. Altogether, our data demonstrate that zinc and copper differentially modulate Aβ production. They further suggest that dimerization of APP-C99 or the specific targeting of individual residues regulating the production of the long, toxic Aβ species, may offer two therapeutic strategies for preventing AD. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Corrosion protection of galvanized steels by silane-based treatments

NASA Astrophysics Data System (ADS)

Yuan, Wei

The possibility of using silane coupling agents as replacements for chromate treatments was investigated on galvanized steel substrates. In order to understand the influence of deposition parameters on silane film formation, pure zinc substrates were first used as a model for galvanized steel to study the interaction between silane coupling agents and zinc surfaces. The silane films formed on pure zinc substrates from aqueous solutions were characterized by ellipsometry, contact angle measurements, reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscopy. The deposition parameters studied include solution concentration, solution dipping time and pH value of the applied solution. It appears that silane film formation involved a true equilibrium of hydrolysis and condensation reactions in aqueous solutions. It has been found that the silane film thickness obtained depends primarily on the solution concentration and is almost independent of the solution dipping time. The molecular orientation of applied silane films is determined by the pH value of applied silane solutions and the isoelectric point of metal substrates. The deposition window in terms of pH value for zinc substrates is between 6.0 and 9.0. The total surface energy of the silane-coated pure zinc substrates decreases with film aging time, the decrease rate, however, is determined by the nature of silane coupling agents. Selected silane coupling agents were applied as prepaint or passivation treatments onto galvanized steel substrates. The corrosion protection provided by these silane-based treatments were evaluated by salt spray test, cyclic corrosion test, electrochemical impedance spectroscopy, and stack test. The results showed that silane coupling agents can possibly be used to replace chromates for corrosion control of galvanized steel substrates. Silane coatings provided by these silane treatments serve mainly as physical barriers. Factors that affect the performance of a silane coupling agent in the application of corrosion control include chemical reactivity, hydrophobic character, siloxane crosslinker network, and film thickness. Good protections afforded by the silane treatments are a synergetic effect of all these factors.

Diel Sampling of Groundwater and Surface Water for Trace Elements and Select Water-Quality Constituents at a Former Zinc Smelter Site near Hegeler, Illinois, August 1-3, 2007

USGS Publications Warehouse

Kay, Robert T.; Groschen, George E.; Dupre, David H.; Drexler, Timothy D.; Thingvold, Karen L.; Rosenfeld, Heather J.

2009-01-01

Surface water can exhibit substantial diel variations in the concentration of a number of constituents. Sampling regimens that do not characterize diel variations in water quality can result in an inaccurate understanding of site conditions and of the threat posed by the site to human health and the environment. Surface- and groundwater affected by acid drainage were sampled every 60 to 90 minutes over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, in Hegeler, Ill. Groundwater-quality data from a well at the site indicate stable, low pH, weakly oxidizing geochemical conditions in the aquifer. With the exceptions of temperature and pH, no constituents exhibited diel variations in groundwater. Variations in temperature and pH likely were not representative of conditions in the aquifer. Surface water was sampled at a site on Grape Creek. Diel variations were observed in temperature, dissolved oxygen, pH, and specific conductance, and in the concentrations of nitrite, barium, iron, lead, vanadium, and possibly uranium. Concentrations during the diel cycles varied by about an order of magnitude for nitrite and varied by about a factor of two for barium, iron, lead, vanadium, and uranium. Temperature, dissolved oxygen, specific conductance, nitrite, barium, lead, and uranium generally reached maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally reached minimum values during the afternoon and maximum values during the night. These variations would need to be accounted for during sampling of surface-water quality in similar hydrologic settings. The temperature variations in surface water were affected by variations in air temperature. Concentrations of dissolved oxygen were affected by variations in the intensity of photosynthetic activity and respiration. Nitrite likely was formed by the oxidation of ammonium by dissolved oxygen and degraded by its anaerobic oxidation by ammonium or as part of the decomposition of organic matter. Variations in pH were affected by the photoreduction of Fe3+ to Fe2+ and the precipitation of iron oxyhydroxides. Diel variations in concentrations of iron and vanadium were likely caused by variations in the dissolution and precipitation of iron oxyhydroxides, oxyhydroxysulfates, and hydrous sulfates, which may have been affected by in the intensity of insolation, iron photoreduction, and the concentration of dissolved oxygen. The concentrations of lead, uranium, and perhaps barium in Grape Creek may have been affected by competition for sorption sites on iron oxyhydroxides. Competition for sorption sites was likely affected by variations in pH and the concentration of Fe2+. Constituent concentrations likely also were affected by precipitation and dissolution of minerals that are sensitive to changes in pH, temperature, oxidation-reduction conditions, and biologic activity. The chemical and biologic processes that resulted in the diel variations observed in Grape Creek occurred within the surface-water column or in the underlying sediments.

In-vitro antibacterial study of zinc oxide nanostructures on Streptococcus sobrinus

NASA Astrophysics Data System (ADS)

Bakhori, Siti Khadijah Mohd; Mahmud, Shahrom; Ann, Ling Chuo; Sirelkhatim, Amna; Hasan, Habsah; Mohamad, Dasmawati; Masudi, Sam'an Malik; Seeni, Azman; Rahman, Rosliza Abd

2014-10-01

Zinc oxide nanostructures were prepared using a pilot plant of zinc oxide boiling furnace. Generally, it produced two types of nanostructures different in morphology; one is rod-like shaped (ZnO-1) and a plate-like shape (ZnO-2). The properties of ZnO were studied by structural, optical and morphological using XRD, PL and FESEM respectively. The XRD patterns confirmed the wurtzite structures of ZnO with the calculated crystallite size of 41 nm (ZnO-1) and 42 nm (ZnO-2) using Scherrer formula. The NBE peaks were determined by photoluminescence spectra which reveal peak at 3.25 eV and 3.23 eV for ZnO-1 and ZnO-2 respectively. Prior to that, the morphologies for both ZnO-1 and ZnO-2 were demonstrated from FESEM micrographs. Subsequently the antibacterial study was conducted using in-vitro broth dilution technique towards a gram positive bacterium Streptococcus sobrinus (ATCC 33478) to investigate the level of antibacterial effect of zinc oxide nanostructures as antibacterial agent. Gradual increment of ZnO concentrations from 10-20 mM affected the inhibition level after twenty four hours of incubation. In conjunction with concentration increment of ZnO, the percentage inhibition towards Streptococcus sobrinus was also increased accordingly. The highest inhibition occurred at 20 mM of ZnO-1 and ZnO-2 for 98% and 77% respectively. It showed that ZnO has good properties as antibacterial agent and relevancy with data presented by XRD, PL and FESEM were determined.

ATR-X mutations cause impaired nuclear location and altered DNA binding properties of the XNP/ATR-X protein.

PubMed

Cardoso, C; Lutz, Y; Mignon, C; Compe, E; Depetris, D; Mattei, M G; Fontes, M; Colleaux, L

2000-10-01

Mutations in the XNP/ATR-X gene, located in Xq13.3, are associated with several X linked mental retardation syndromes, the best known being alpha thalassaemia with mental retardation (ATR-X). The XNP/ATR-X protein belongs to the family of SWI/SNF DNA helicases and contains three C2-C2 type zinc fingers of unknown function. Previous studies have shown that 65% of mutations of XNP have been found within the zinc finger domain (encoded by exons 7, 8, and the beginning of exon 9) while 35% of the mutations have been found in the helicase domain extending over 3 kb at the C-terminus of the protein. Although different types of mutations have been identified, no specific genotype-phenotype correlation has been found, suggesting that gene alteration leads to a loss of function irrespective of mutation type. Our aims were to understand the function of the XNP/ATR-X protein better, with specific attention to the functional consequences of mutations to the zinc finger domain. We used monoclonal antibodies directed against the XNP/ATR-X protein and performed immunocytochemical and western blot analyses, which showed altered or absent XNP/ATR-X expression in cells of affected patients. In addition, we used in vitro experiments to show that the zinc finger domain can mediate double stranded DNA binding and found that the DNA binding capacity of mutant forms in ATR-X patients is severely reduced. These data provide insights into the understanding of the functional significance of XNP/ATR-X mutations.

The Challenges and Opportunities Associated with Biofortification of Pearl Millet (Pennisetum glaucum) with Elevated Levels of Grain Iron and Zinc

PubMed Central

Manwaring, Hanna R.; Bligh, H. F. J.; Yadav, Rattan

2016-01-01

Deficiencies of essential micronutrients such as iron and zinc are the cause of extensive health problems in developing countries. They adversely affect performance, productivity and are a major hindrance to economic development. Since many people who suffer from micronutrient deficiencies are dependent on staple crops to meet their dietary requirements, the development of crop cultivars with increased levels of micronutrients in their edible parts is becoming increasingly recognized as a sustainable solution. This is largely facilitated by genetics and genomic platforms. The cereal crop pearl millet (Pennisetum glaucum), is an excellent candidate for genetic improvement due to its ability to thrive in dry, semi-arid regions, where farming conditions are often unfavorable. Not only does pearl millet grow in areas where other crops such as maize and wheat do not survive, it contains naturally high levels of micronutrients, proteins and a myriad of other health benefitting characteristics. This review discusses the current status of iron and zinc deficiencies and reasons why interventions such as fortification, supplementation, and soil management are neither practicable nor affordable in poverty stricken areas. We argue that the most cost effective, sustainable intervention strategy is to biofortify pearl millet with enhanced levels of bioavailable iron and zinc. We discuss how naturally occurring genetic variations present in germplasm collections can be incorporated into elite, micronutrient rich varieties and what platforms are available to drive this research. We also consider the logistics of transgenic methods that could facilitate the improvement of the pearl millet gene pool. PMID:28066495

Differential Regulation of Gene and Protein Expression by Zinc Oxide Nanoparticles in Hen’s Ovarian Granulosa Cells: Specific Roles of Nanoparticles

PubMed Central

Zhao, Yong; Li, Lan; Zhang, Peng-Fei; Shen, Wei; Liu, Jing; Yang, Fen-Fang; Liu, Hong-Bo; Hao, Zhi-Hui

2015-01-01

Annually, tons and tons of zinc oxide nanoparticles (ZnO NPs) are produced in the world. And they are applied in almost all aspects of our life. Their release from the products into environment may pose issue for human health. Although many studies have reported the adverse effects of ZnO NPs on organisms, little is known about the effects on female reproductive systems or the related mechanisms. Quantitative proteomics have not been applied although quantitative transcriptomics have been used in zinc oxide nanoparticles (ZnO NPs) research. Genes are very important players however proteins are the real actors in the biological systems. By using hen’s ovarian granulosa cells, it was found that ZnO-NP-5μg/ml and ZnSO4-10μg/ml treatments produced the same amount of intracellular Zn and resulted in similar cell growth inhibition. And NPs were found in the treated cells. However, ZnO-NP-5μg/ml specifically regulated the expression of genes and proteins compared with that in ZnSO4-10μg/ml treatment. For the first time, this investigation reports that intact NPs produce different impacts on the expression of genes and proteins involved in specific pathways compared to that by Zn2+. The findings enrich our knowledge for the molecular insights of zinc oxide nanoparticles effects on the female reproductive systems. This also may raise the health concern that ZnO NPs may adversely affect the female reproductive systems through regulation of specific signaling pathways. PMID:26460738

Differential Regulation of Gene and Protein Expression by Zinc Oxide Nanoparticles in Hen's Ovarian Granulosa Cells: Specific Roles of Nanoparticles.

PubMed

Zhao, Yong; Li, Lan; Zhang, Peng-Fei; Shen, Wei; Liu, Jing; Yang, Fen-Fang; Liu, Hong-Bo; Hao, Zhi-Hui

2015-01-01

Annually, tons and tons of zinc oxide nanoparticles (ZnO NPs) are produced in the world. And they are applied in almost all aspects of our life. Their release from the products into environment may pose issue for human health. Although many studies have reported the adverse effects of ZnO NPs on organisms, little is known about the effects on female reproductive systems or the related mechanisms. Quantitative proteomics have not been applied although quantitative transcriptomics have been used in zinc oxide nanoparticles (ZnO NPs) research. Genes are very important players however proteins are the real actors in the biological systems. By using hen's ovarian granulosa cells, it was found that ZnO-NP-5μg/ml and ZnSO4-10μg/ml treatments produced the same amount of intracellular Zn and resulted in similar cell growth inhibition. And NPs were found in the treated cells. However, ZnO-NP-5μg/ml specifically regulated the expression of genes and proteins compared with that in ZnSO4-10μg/ml treatment. For the first time, this investigation reports that intact NPs produce different impacts on the expression of genes and proteins involved in specific pathways compared to that by Zn2+. The findings enrich our knowledge for the molecular insights of zinc oxide nanoparticles effects on the female reproductive systems. This also may raise the health concern that ZnO NPs may adversely affect the female reproductive systems through regulation of specific signaling pathways.

Zinc and Wound Healing: A Review of Zinc Physiology and Clinical Applications.

PubMed

Kogan, Samuel; Sood, Aditya; Garnick, Mark S

2017-04-01

Our understanding of the role of zinc in normal human physiology is constantly expanding, yet there are major gaps in our knowledge with regard to the function of zinc in wound healing. This review aims to provide the clinician with sufficient understanding of zinc biology and an up-to-date perspective on the role of zinc in wound healing. Zinc is an essential ion that is crucial for maintenance of normal physiology, and zinc deficiency has many manifestations ranging from delayed wound healing to immune dysfunction and impairment of multiple sensory systems. While consensus has been reached regarding the detrimental effects of zinc deficiency on wound healing, there is considerable discord in the literature on the optimal methods and true benefits of zinc supplementation.

Zinc at glutamatergic synapses.

PubMed

Paoletti, P; Vergnano, A M; Barbour, B; Casado, M

2009-01-12

It has long been known that the mammalian forebrain contains a subset of glutamatergic neurons that sequester zinc in their synaptic vesicles. This zinc may be released into the synaptic cleft upon neuronal activity. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate receptors and transporters. Among these targets, NMDA receptors appear particularly interesting because certain NMDA receptor subtypes (those containing the NR2A subunit) contain allosteric sites exquisitely sensitive to extracellular zinc. The existence of these high-affinity zinc binding sites raises the possibility that zinc may act both in a phasic and tonic mode. Changes in zinc concentration and subcellular zinc distribution have also been described in several pathological conditions linked to glutamatergic transmission dysfunctions. However, despite intense investigation, the functional significance of vesicular zinc remains largely a mystery. In this review, we present the anatomy and the physiology of the glutamatergic zinc-containing synapse. Particular emphasis is put on the molecular and cellular mechanisms underlying the putative roles of zinc as a messenger involved in excitatory synaptic transmission and plasticity. We also highlight the many controversial issues and unanswered questions. Finally, we present and compare two widely used zinc chelators, CaEDTA and tricine, and show why tricine should be preferred to CaEDTA when studying fast transient zinc elevations as may occur during synaptic activity.

Zinc-mediated Allosteric Inhibition of Caspase-6*

PubMed Central

Velázquez-Delgado, Elih M.; Hardy, Jeanne A.

2012-01-01

Zinc and caspase-6 have independently been implicated in several neurodegenerative disorders. Depletion of zinc intracellularly leads to apoptosis by an unknown mechanism. Zinc inhibits cysteine proteases, including the apoptotic caspases, leading to the hypothesis that zinc-mediated inhibition of caspase-6 might contribute to its regulation in a neurodegenerative context. Using inductively coupled plasma optical emission spectroscopy, we observed that caspase-6 binds one zinc per monomer, under the same conditions where the zinc leads to complete loss of enzymatic activity. To understand the molecular details of zinc binding and inhibition, we performed an anomalous diffraction experiment above the zinc edge. The anomalous difference maps showed strong 5σ peaks, indicating the presence of one zinc/monomer bound at an exosite distal from the active site. Zinc was not observed bound to the active site. The zinc in the exosite was liganded by Lys-36, Glu-244, and His-287 with a water molecule serving as the fourth ligand, forming a distorted tetrahedral ligation sphere. This exosite appears to be unique to caspase-6, as the residues involved in zinc binding were not conserved across the caspase family. Our data suggest that binding of zinc at the exosite is the primary route of inhibition, potentially locking caspase-6 into the inactive helical conformation. PMID:22891250

Finger millet (Eleucine coracana) flour as a vehicle for fortification with zinc.

PubMed

Tripathi, Bhumika; Platel, Kalpana

2010-01-01

Millets, being less expensive compared to cereals and the staple for the poorer sections of population, could be the choice for fortification with micronutrients such as zinc. In view of this, finger millet, widely grown and commonly consumed in southern India, was explored as a vehicle for fortification with zinc in this investigation. Finger millet flour fortified with either zinc oxide or zinc stearate so as to provide 50mg zinc per kg flour, was specifically examined for the bioaccessibility of the fortified mineral, as measured by in vitro simulated gastrointestinal digestion procedure and storage stability. Addition of the zinc salts increased the bioaccessible zinc content by 1.5-3 times that of the unfortified flour. Inclusion of EDTA along with the fortified salt significantly enhanced the bioaccessibility of zinc from the fortified flours, the increase being three-fold. Inclusion of citric acid along with the zinc salt and EDTA during fortification did not have any additional beneficial effect on zinc bioaccessiblity. Moisture and free fatty acid contents of the stored fortified flours indicated the keeping quality of the same, up to 60 days. Both zinc oxide and zinc stearate were equally effective as fortificants, when used in combination with EDTA as a co-fortificant. The preparation of either roti or dumpling from the fortified flours stored up to 60 days did not result in any significant compromise in the bioaccessible zinc content. Thus, the present study has revealed that finger millet flour can effectively be used as a vehicle for zinc fortification to derive additional amounts of bioaccessible zinc, with reasonably good storage stability, to combat zinc deficiency. Copyright 2009 Elsevier GmbH. All rights reserved.

Serum alkaline phosphatase activity during zinc deficiency and long-term inflammatory stress.

PubMed

Naber, T H; Baadenhuysen, H; Jansen, J B; van den Hamer, C J; van den Broek, W

1996-05-30

A decrease in serum zinc can be caused by a real zinc deficiency but can also be caused by an apparent zinc deficiency, e.g. in inflammatory stress. The aim of this study was to evaluate the diagnostic power of serum alkaline phosphatase (AP) activity in the discrimination between pathophysiologic states of "real" and "apparent" zinc deficiency. A decrease in serum zinc was induced in growing and adult rats, by providing a diet low in zinc and by causing inflammatory stress. AP activity was determined using reagents low or enriched in zinc. Serum AP was decreased in zinc-deficient adult rats (P < 0.01). In zinc-deficient growing rats AP activity was not different from normal rats but AP activity decreased rapidly. In the same growing rats a significant difference was found in AP activities determined using buffers low and enriched in zinc (P < 0.001) between both groups of rats. After inducing inflammatory stress a decrease in AP activity (P < 0.01) and serum zinc (P < 0.001) was seen during the first few days. After the initial phase of inflammation AP activity normalized, serum zinc showed a rise which after correction for the decrease in serum albumin reached the level of the control rats. A difference in AP activity in buffers low and enriched in zinc was observed only during the first few days after induction of inflammatory stress (P < 0.001). Probably the method of measurement of the difference in enzyme activity, using buffers low and enriched in zinc, can be used as an indication for zinc deficiency in situations with changing AP enzyme concentrations. AP activity is decreased during the initial phase of inflammatory stress due to a decrease in serum zinc.

STAT5-glucocorticoid receptor interaction and MTF-1 regulate the expression of ZnT2 (Slc30a2) in pancreatic acinar cells

PubMed Central

Guo, Liang; Lichten, Louis A.; Ryu, Moon-Suhn; Liuzzi, Juan P.; Wang, Fudi; Cousins, Robert J.

2010-01-01

The exocrine pancreas plays an important role in endogenous zinc loss by regulating excretion into the intestinal tract and hence influences the dietary zinc requirement. The present experiments show that the zinc transporter ZnT2 (Slc30a2) is localized to the zymogen granules and that dietary zinc restriction in mice decreased the zinc concentration of zymogen granules and ZnT2 expression. Excess zinc given orally increased ZnT2 expression and was associated with increased pancreatic zinc accumulation. Rat AR42J acinar cells when induced into a secretory phenotype, using the glucocorticoid analog dexamethasone (DEX), exhibited increased ZnT2 expression and labile zinc as measured with a fluorophore. DEX administrated to mice also induced ZnT2 expression that accompanied a reduction of the pancreatic zinc content. ZnT2 promoter analyses identified elements required for responsiveness to zinc and DEX. Zinc regulation was traced to a MRE located downstream from the ZnT2 transcription start site. Responsiveness to DEX is produced by two upstream STAT5 binding sites that require the glucocorticoid receptor for activation. ZnT2 knockdown in the AR42J cells using siRNA resulted in increased cytoplasmic zinc and decreased zymogen granule zinc that further demonstrated that ZnT2 may mediate the sequestration of zinc into zymogen granules. We conclude, based upon experiments with intact mice and pancreatic acinar cells in culture, that ZnT2 participates in zinc transport into pancreatic zymogen granules through a glucocorticoid pathway requiring glucocorticoid receptor and STAT5, and zinc-regulated signaling pathways requiring MTF-1. The ZnT2 transporter appears to function in a physiologically responsive manner involving entero-pancreatic zinc trafficking. PMID:20133611

Decrease of non-point zinc runoff using porous concrete.

PubMed

Harada, Shigeki; Komuro, Yoshinori

2010-01-01

The use of porous concrete columns to decrease the amount of zinc in stormwater runoff is examined. The concentration of zinc in a simulated stormwater fluid (zinc acetate solution), fed through concrete columns (slashed circle10x10cm) decreased by 50-81%, suggesting physical adsorption of zinc by the porous concrete. We propose the use of porous concrete columns (slashed circle50x10cm) as the base of sewage traps. Longer-term, high-zinc concentration monitoring revealed that porous concrete blocks adsorb 38.6mgcm(-3) of zinc. A period of no significant zinc runoff (with an acceptable concentration of zinc in runoff of 0.03mgL(-1), a zinc concentration equal to the Japanese Environmental Standard) is estimated for 41years using a 1-ha catchment area with 20 porous concrete sewage traps. Scanning electron microscopy of the porous concrete used in this study indicates that the needle-like particles formed by hydration action significantly increase zinc adsorption. Evidence suggests that the hydrant is ettringite and has an important role in zinc adsorption, the resulting immobilization of zinc and the subsequent effects on groundwater quality. Copyright 2009 Elsevier Ltd. All rights reserved.

The Relationship between Zinc Intake and Serum/Plasma Zinc Concentration in Children: A Systematic Review and Dose-Response Meta-Analysis

PubMed Central

Moran, Victoria Hall; Stammers, Anna-Louise; Medina, Marisol Warthon; Patel, Sujata; Dykes, Fiona; Souverein, Olga W.; Dullemeijer, Carla; Pérez-Rodrigo, Carmen; Serra-Majem, Lluis; Nissensohn, Mariela; Lowe, Nicola M.

2012-01-01

Recommendations for zinc intake during childhood vary widely across Europe. The EURRECA project attempts to consolidate the basis for the definition of micronutrient requirements, taking into account relationships among intake, status and health outcomes, in order to harmonise these recommendations. Data on zinc intake and biomarkers of zinc status reported in randomised controlled trials (RCTs) can provide estimates of dose-response relationships which may be used for underpinning zinc reference values. This systematic review included all RCTs of apparently healthy children aged 1–17 years published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient () was calculated for each individual study and calculated the overall pooled and SE () using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status indicated that a doubling of the zinc intake increased the serum/plasma zinc status by 9%. This evidence can be utilised, together with currently used balance studies and repletion/depletion studies, when setting zinc recommendations as a basis for nutrition policies. PMID:23016120

The biological inorganic chemistry of zinc ions.

PubMed

Krężel, Artur; Maret, Wolfgang

2016-12-01

The solution and complexation chemistry of zinc ions is the basis for zinc biology. In living organisms, zinc is redox-inert and has only one valence state: Zn(II). Its coordination environment in proteins is limited by oxygen, nitrogen, and sulfur donors from the side chains of a few amino acids. In an estimated 10% of all human proteins, zinc has a catalytic or structural function and remains bound during the lifetime of the protein. However, in other proteins zinc ions bind reversibly with dissociation and association rates commensurate with the requirements in regulation, transport, transfer, sensing, signalling, and storage. In contrast to the extensive knowledge about zinc proteins, the coordination chemistry of the "mobile" zinc ions in these processes, i.e. when not bound to proteins, is virtually unexplored and the mechanisms of ligand exchange are poorly understood. Knowledge of the biological inorganic chemistry of zinc ions is essential for understanding its cellular biology and for designing complexes that deliver zinc to proteins and chelating agents that remove zinc from proteins, for detecting zinc ion species by qualitative and quantitative analysis, and for proper planning and execution of experiments involving zinc ions and nanoparticles such as zinc oxide (ZnO). In most investigations, reference is made to zinc or Zn 2+ without full appreciation of how biological zinc ions are buffered and how the d-block cation Zn 2+ differs from s-block cations such as Ca 2+ with regard to significantly higher affinity for ligands, preference for the donor atoms of ligands, and coordination dynamics. Zinc needs to be tightly controlled. The interaction with low molecular weight ligands such as water and inorganic and organic anions is highly relevant to its biology but in contrast to its coordination in proteins has not been discussed in the biochemical literature. From the discussion in this article, it is becoming evident that zinc ion speciation is important in zinc biochemistry and for biological recognition as a variety of low molecular weight zinc complexes have already been implicated in biological processes, e.g. with ATP, glutathione, citrate, ethylenediaminedisuccinic acid, nicotianamine, or bacillithiol. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The Components of the Unique Zur Regulon of Cupriavidus metallidurans Mediate Cytoplasmic Zinc Handling

PubMed Central

Bütof, Lucy; Schmidt-Vogler, Christopher; Herzberg, Martin; Große, Cornelia

2017-01-01

ABSTRACT Zinc is an essential trace element, yet it is toxic at high concentrations. In the betaproteobacterium Cupriavidus metallidurans, the highly efficient removal of surplus zinc from the periplasm is responsible for the outstanding metal resistance of the organism. Rather than having a typical Zur-dependent, high-affinity ATP-binding cassette transporter of the ABC protein superfamily for zinc uptake at low concentrations, C. metallidurans has the secondary zinc importer ZupT of the zinc-regulated transporter, iron-regulated transporter (ZRT/IRT)-like protein (ZIP) family. It is important to understand, therefore, how this zinc-resistant bacterium copes with exposure to low zinc concentrations. Members of the Zur regulon in C. metallidurans were identified by comparing the transcriptomes of a Δzur mutant and its parent strain. The consensus sequence of the Zur-binding box was derived for the zupTp promoter-regulatory region by use of a truncation assay. The motif was used to predict possible Zur boxes upstream of Zur regulon members. The binding of Zur to these boxes was confirmed. Two Zur boxes upstream of the cobW1 gene, encoding a putative zinc chaperone, proved to be required for complete repression of cobW1 and its downstream genes in cells cultivated in mineral salts medium. A Zur box upstream of each of zur-cobW2, cobW3, and zupT permitted both low expression levels of these genes and their upregulation under conditions of zinc starvation. This demonstrates a compartmentalization of zinc homeostasis in C. metallidurans, where the periplasm is responsible for the removal of surplus zinc, cytoplasmic components are responsible for the management of zinc as an essential cofactor, and the two compartments are connected by ZupT. IMPORTANCE Elucidating zinc homeostasis is necessary for understanding both host-pathogen interactions and the performance of free-living bacteria in their natural environments. Escherichia coli acquires zinc under conditions of low zinc concentrations via the Zur-controlled ZnuABC importer of the ABC superfamily, and this was also the paradigm for other bacteria. In contrast, the heavy-metal-resistant bacterium C. metallidurans achieves high tolerance to zinc through sophisticated zinc handling and efflux systems operating on periplasmic zinc ions, so that removal of surplus zinc is a periplasmic feature in this bacterium. It is shown here that this process is augmented by the management of zinc by cytoplasmic zinc chaperones, whose synthesis is controlled by the Zur regulator. This demonstrates a new mechanism, involving compartmentalization, for organizing zinc homeostasis. PMID:28808127

Repletion of Zinc and Iron Deficiencies Improves Cognition of Premenopausal Women.

DTIC Science & Technology

1997-10-01

to our earlier observations in premenopausal women (1, 13) and are consistent with the fact that many premenopausal women select diets that are low...women: associations of diet with serum ferritin and plasma zinc disappearance, and of serum ferritin with plasma zinc and plasma zinc disappearance...women: Associations of diet with serum ferritin and plasma zinc disappearance and of serum ferritin with plasma zinc and plasma zinc disappearance. J

High Gloss Corrosion-Resistant Coatings

DTIC Science & Technology

1991-08-27

removal and parts by weight of a zinc salt of a substituted benioic certainly saves on manpower that would generally be acid , and 4 to 27 pans by...system consisting essentially of zinc molybdate, zinc salt of benzoic acids , and zinc phosphate in specific ratio’s. The coating exhibits good...polymeric binder and 18 to 70 percent by weight of a pigment system consisting essen- tially of zinc molybdate. zinc salt of benzoic acids , and zinc

Zinc and its transporters, pancreatic beta cells, and insulin metabolism

USDA-ARS?s Scientific Manuscript database

Zinc is an essential trace metal for life. Two families of zinc transporters, SLC30A (ZnT) and SLC39A (ZIP) are required for maintaining cellular zinc homeostasis. ZnTs function to decrease cytoplasmic zinc concentrations whereas ZIPs do the opposite. Expression of zinc transporters can be tissue/ce...

Reduction of zinc emissions from buildings; the policy of Amsterdam.

PubMed

Gouman, E

2004-01-01

In Amsterdam zinc coming from the roofs and gutters of the buildings accounts for about 50% of the zinc emissions into the surface water (i.e. canals and rivers). This causes water and sediment pollution. Dumping strongly polluted sediment costs ten times more then dumping less polluted mud. Therefore the City of Amsterdam has developed a policy for reducing the zinc emissions from buildings based on the current environmental legislation and the current national targets for surface water quality. Zinc roofs on new and renovated buildings are not permitted. Run off water from zinc roofs of existing buildings is allowed to contain a maximum of 200 microg/l zinc. For the zinc gutters of houses, Amsterdam will promote measures to reduce zinc emissions. To investigate the feasibility of measures, research has been carried out on the zinc emissions of gutters and the effect of covering gutters with an impermeable foil. This research shows clearly that covering zinc gutters with EPDM foil reduces the zinc emissions by 90% from 8.5 to 0.88 gram per square metre per year including the atmospheric deposition.

Effect of in vitro zinc supplementation on HSPs expression and Interleukin 10 production in heat treated peripheral blood mononuclear cells of transition Sahiwal and Karan Fries cows.

PubMed

Sheikh, Aasif Ahmad; Aggarwal, Anjali; Aarif, Ovais

2016-02-01

The changing climatic scenario with apprehended rise in global temperature is likely to affect the livestock adversely vis-à-vis production and reproduction. This has prompted more focus in addressing the unfavorable effects of thermal stress in livestock system. Presuming that the trace element zinc is indispensible for cellular antioxidant system and immune function, the present study was designed to investigate the effect of zinc treatment on heat stress alleviation and immune modulation in peripheral blood mononuclear cells (PBMC) of indigenous and crossbred transition cows. Twelve cows, six each of Sahiwal and Karan Fries (KF) in their second parity with confirmed pregnancy were selected for the experiment. The blood samples were collected at -21, 0 and +21 days in relation to expected date of calving. The experiment was carried out in vitro after isolating PBMC from whole blood. The 48h cultured PBMC were subjected to assorted levels of exposures viz. 37°C, 42°C to impose heat stress and 42°C+zinc to alleviate heat stress and modulate immunity. The PBMC viability was 86%, 69% and 78%, respectively. The mRNA expression of heat shock proteins (HSP 40, 70 and 90α) and Interleukin-10 (IL-10) production varied between the two breeds vis-à-vis days and levels of exposure. The mRNA expression of HSP40 and HSP70 was significantly (P<0.05) higher in Karan Fries than the Sahiwal cows. Both the breeds showed maximum expression of HSP on the day of parturition, more so in KF than Sahiwal. There was a significant (P<0.05) difference in the HSP mRNA expression at different levels of exposure. Zinc treatment to heat stressed PBMC caused a significant (P<0.05) down regulation of HSP. For immune status, anti-inflammatory cytokine, IL-10 in the culture supernatant was accessed. The IL-10 was significantly (P<0.05) higher in Karan Fries (168.18±14.09pg/ml) than the Sahiwal cows (147.24±11.82pg/ml). The IL-10 concentration was highest on the day of calving. Zinc treatment reduced the IL-10 concentration. From the study, it could be concluded that the zinc supplementation in heat stressed PBMC can ameliorate thermal stress and modulate immune response which can act as a model for reducing heat stress during the periparturient period in tropical livestock. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of process parameters on Twin Wire Arc spray pattern shape

DOE PAGES

Hall, Aaron Christopher; McCloskey, James Francis; Horner, Allison Lynne

2015-04-20

A design of experiments approach was used to describe process parameter—spray pattern relationships in the Twin Wire Arc process using zinc feed stock in a TAFA 8835 (Praxair, Concord, NH, USA) spray torch. Specifically, the effects of arc current, primary atomizing gas pressure, and secondary atomizing gas pressure on spray pattern size, spray pattern flatness, spray pattern eccentricity, and coating deposition rate were investigated. Process relationships were investigated with the intent of maximizing or minimizing each coating property. It was determined that spray pattern area was most affected by primary gas pressure and secondary gas pressure. Pattern eccentricity was mostmore » affected by secondary gas pressure. Pattern flatness was most affected by primary gas pressure. Lastly, coating deposition rate was most affected by arc current.« less

The effect of process parameters on Twin Wire Arc spray pattern shape

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, Aaron Christopher; McCloskey, James Francis; Horner, Allison Lynne

A design of experiments approach was used to describe process parameter—spray pattern relationships in the Twin Wire Arc process using zinc feed stock in a TAFA 8835 (Praxair, Concord, NH, USA) spray torch. Specifically, the effects of arc current, primary atomizing gas pressure, and secondary atomizing gas pressure on spray pattern size, spray pattern flatness, spray pattern eccentricity, and coating deposition rate were investigated. Process relationships were investigated with the intent of maximizing or minimizing each coating property. It was determined that spray pattern area was most affected by primary gas pressure and secondary gas pressure. Pattern eccentricity was mostmore » affected by secondary gas pressure. Pattern flatness was most affected by primary gas pressure. Lastly, coating deposition rate was most affected by arc current.« less

Improved zinc electrode and rechargeable zinc-air battery

DOEpatents

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.

Role of nutritional zinc in the prevention of osteoporosis.

PubMed

Yamaguchi, Masayoshi

2010-05-01

Zinc is known as an essential nutritional factor in the growth of the human and animals. Bone growth retardation is a common finding in various conditions associated with dietary zinc deficiency. Bone zinc content has been shown to decrease in aging, skeletal unloading, and postmenopausal conditions, suggesting its role in bone disorder. Zinc has been demonstrated to have a stimulatory effect on osteoblastic bone formation and mineralization; the metal directly activates aminoacyl-tRNA synthetase, a rate-limiting enzyme at translational process of protein synthesis, in the cells, and it stimulates cellular protein synthesis. Zinc has been shown to stimulate gene expression of the transcription factors runt-related transcription factor 2 (Runx2) that is related to differentiation into osteoblastic cells. Moreover, zinc has been shown to inhibit osteoclastic bone resorption due to inhibiting osteoclast-like cell formation from bone marrow cells and stimulating apoptotic cell death of mature osteoclasts. Zinc has a suppressive effect on the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-induced osteoclastogenesis. Zinc transporter has been shown to express in osteoblastic and osteoclastic cells. Zinc protein is involved in transcription. The intake of dietary zinc causes an increase in bone mass. beta-Alanyl-L: -histidinato zinc (AHZ) is a zinc compound, in which zinc is chelated to beta-alanyl-L: -histidine. The stimulatory effect of AHZ on bone formation is more intensive than that of zinc sulfate. Zinc acexamate has also been shown to have a potent-anabolic effect on bone. The oral administration of AHZ or zinc acexamate has the restorative effect on bone loss under various pathophysiologic conditions including aging, skeletal unloading, aluminum bone toxicity, calcium- and vitamin D-deficiency, adjuvant arthritis, estrogen deficiency, diabetes, and fracture healing. Zinc compounds may be designed as new supplementation factor in the prevention and therapy of osteoporosis.

Profiling of zinc altered gene expression in human prostate normal versus cancer cells: a time course study

PubMed Central

Lin, Shu-fei; Wei, Hua; Maeder, Dennis; Franklin, Renty B.; Feng, Pei

2010-01-01

We have demonstrated that zinc exposure induces apoptosis in human prostate cancer cells (PC-3) and benign hyperplasia cells (BPH), but not in normal prostate cells (HPR-1). However, the mechanisms underlying the effects of zinc on prostate cancer cell growth and zinc homeostasis remain unclear. To explore the zinc effect on gene expression profiles in normal (HPR-1) and malignant prostate cells (PC-3), we conducted a time course study of Zn treatment with microarray analysis. Microarray data were evaluated and profiled using computational approach for the primary and secondary data analyses. Final analyses were focused on the genes: 1. highly sensitive to zinc, 2. associated with zinc homeostasis, i.e. metallothioneins (MTs), solute zinc carriers (ZIPs) and zinc exporters (ZnTs), 3. relevant to several oncogenic pathways. Zinc-mediated mRNA levels of MT isotypes were further validated by semi-quantitative RT-PCR. Results showed that zinc effect on genome-wide expression patterns was cell type specific, and zinc appeared to have mainly down-regulatory effects on thousands of genes (1,953 in HPR-1; 3,534 in PC-3) with a threshold of ±2.5-fold, while fewer genes were up-regulated (872 in HPR-1; 571 in PC-3). The patterns of zinc effect on functional MT genes’ expression provided evidence for the cell-type dependent zinc accumulation and zinc-induced apoptosis in prostate cells. In PC-3 cells, zinc significantly up-regulated the expression of MT-1 isotypes -J and -M, denoted previously as “non-functional” MT genes, and now a depictive molecular structure of MT-1J was proposed. Examination of genes involved in oncogenic pathways indicated that certain genes, e.g. Fos, Akt1, Jak3 and PI3K were highly regulated by zinc with cell type specificity. This work provided an extensive database on zinc related prostate cancer research. The strategy of data analysis was devoted to find genes highly sensitive to Zn, and the genes associated with zinc accumulation and zinc-induced apoptosis. The results indicate that zinc regulation of gene expression is cell-type specific, and MT genes play important roles in prostate malignancy. PMID:19071009

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.

2014-12-15

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each ofmore » which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes« less

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks.

PubMed

Que, Emily L; Bleher, Reiner; Duncan, Francesca E; Kong, Betty Y; Gleber, Sophie C; Vogt, Stefan; Chen, Si; Garwin, Seth A; Bayer, Amanda R; Dravid, Vinayak P; Woodruff, Teresa K; O'Halloran, Thomas V

2015-02-01

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

PubMed Central

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; Kong, Betty Y.; Gleber, Sophie C.; Vogt, Stefan; Chen, Si; Garwin, Seth A.; Bayer, Amanda R.; Dravid, Vinayak; Woodruff, Teresa K.; O’Halloran, Thomas V.

2015-01-01

Fertilization of a mammalian egg induces a series of ‘zinc sparks’ that are necessary for inducing the egg-to-embryo transition. Despite the importance of these zinc efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches to resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy dispersive spectroscopy, X-ray fluorescence microscopy, and 3D elemental tomography for high resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 106 zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes. PMID:25615666

Interrelationships among mediators of cellular zinc homeostasis in healthy and type 2 diabetes mellitus populations.

PubMed

Chu, Anna; Foster, Meika; Hancock, Dale; Petocz, Peter; Samman, Samir

2017-04-01

The involvement of zinc in multiple physiological systems requires tight control of cellular zinc concentration. This study aims to explore the relationships among selected mediators of cellular zinc homeostasis in an apparently healthy (AH) population and a cohort with type 2 diabetes mellitus (T2DM). Baseline data of three trials forming two cohorts, AH (n = 70) and T2DM (n = 42), were used for multivariate analyses to identify groupings within ten zinc transporter and metallothionein (MT) gene expressions, stratified by health status. Multiple regression models were used to explore relationships among zinc transporter/MT groupings and plasma zinc. Gene expression of zinc transporters and MTs, with the exception of ZnT6, were significantly lower in the T2DM cohort (p < 0.01). Cluster analysis showed that the groupings of zinc transporters and MTs were largely similar between the two cohorts, with the exception for ZnT1 and ZIP7. Zinc transporters and MTs were significant determinants of plasma zinc (r 2 = 0.48, p = 0.001) in the AH cohort, but not in the T2DM cohort. The current study suggests altered cellular zinc homeostasis in T2DM and supports the use of multiple zinc transporters and MTs groupings to further understand zinc homeostasis in health and T2DM. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective, quantitative measurement of releasable synaptic zinc in human autopsy hippocampal brain tissue from Alzheimer’s disease patients

PubMed Central

Bjorklund, Nicole L.; Sadagoparamanujam, V.M.; Taglialatela, Giulio

2011-01-01

Aberrant central nervous system zinc homeostasis has been reported in Alzheimer’s disease (AD). However, there are conflicting reports describing zinc concentration either increased or decreased in the brain of AD patients. Such discrepancies may be due to differences in the brain area examined, zinc detection method, and/or tissue composition. Furthermore, detection and measurement of the releasable zinc pool in autopsy tissue is difficult and usually unreliable. Obtaining an adequate assessment of this releasable zinc pool is of particular significance in AD research in that zinc can coordinate with and stabilize toxic amyloid beta oligomers, which are believed to play a key role in AD neuropathology. In addition, zinc released into the synaptic cleft can interact with the postsynaptic neurons causing altered signaling and synaptic dysfunction, which is a well established event in AD. The method presented here combines two approaches, biochemical fractionation and atomic absorption spectrophotometry, to allow, in addition to extracellular zinc concentration, the reliable and quantitative measurement of zinc specifically localized in synaptic vesicles, which contain the majority of the neuronal releasable zinc. Using this methodology, we found that synaptic vesicle zinc concentrations were increased in AD hippocampi compared to age-matched controls and that this increase in releasable zinc matched increased concentration of zinc in the extracellular space. PMID:21945000

Zinc finger proteins in cancer progression.

PubMed

Jen, Jayu; Wang, Yi-Ching

2016-07-13

Zinc finger proteins are the largest transcription factor family in human genome. The diverse combinations and functions of zinc finger motifs make zinc finger proteins versatile in biological processes, including development, differentiation, metabolism and autophagy. Over the last few decades, increasing evidence reveals the potential roles of zinc finger proteins in cancer progression. However, the underlying mechanisms of zinc finger proteins in cancer progression vary in different cancer types and even in the same cancer type under different types of stress. Here, we discuss general mechanisms of zinc finger proteins in transcription regulation and summarize recent studies on zinc finger proteins in cancer progression. In this review, we also emphasize the importance of further investigations in elucidating the underlying mechanisms of zinc finger proteins in cancer progression.

The components of the unique Zur regulon of Cupriavidus metallidurans mediate cytoplasmic zinc handling.

PubMed

Bütof, Lucy; Schmidt-Vogler, Christopher; Herzberg, Martin; Große, Cornelia; Nies, Dietrich H

2017-08-14

Zinc is an essential trace element and at the same time it is toxic at high concentrations. In the beta-proteobacterium Cupriavidus metallidurans the highly efficient removal of surplus zinc from the periplasm is responsible for its outstanding metal resistance. Rather than having a typical Zur-dependent, high-affinity ATP-binding cassette transporter of the ABC protein superfamily for zinc uptake at low concentrations, C. metallidurans instead has the secondary zinc importer ZupT of the ZRT/IRT (ZIP) family. It is important to understand, therefore, how this zinc-resistant bacterium copes when it is exposed to low zinc concentrations. Members of the Zur regulon in C. metallidurans were identified by comparing the transcriptomes of a Δ zur mutant and its parent strain. The consensus sequence of the Zur-binding box was derived for the zupTp promoter-regulatory region using a truncation assay. The motif was used to predict possible Zur-boxes upstream of Zur regulon members. Binding of Zur to these boxes was confirmed. Two Zur-boxes upstream of the cobW 1 gene, encoding a putative zinc chaperone, proved to be required for complete repression of cobW 1 and its downstream genes in cells cultivated in mineral salts medium. A Zur box upstream of each of zur-cobW 2 , cobW 3 and zupT permitted low-expression level of these genes plus their up-regulation under zinc starvation conditions. This demonstrates a compartmentalization of zinc homeostasis in C. metallidurans with the periplasm being responsible for removal of surplus zinc and cytoplasmic components for management of zinc as an essential co-factor, with both compartments connected by ZupT. Importance Elucidating zinc homeostasis is necessary to understand both host-pathogen interactions and performance of free-living bacteria in their natural environment. Escherichia coli acquires zinc under low zinc concentrations by the Zur-controlled ZnuABC importer of the ABC superfamily, and this was also the paradigm for other bacteria. In contrast, the heavy metal-resistant bacterium C. metallidurans achieves high tolerance to zinc due to sophisticated zinc handling and efflux systems operating on periplasmic zinc ions, so that removal of surplus zinc is a periplasmic feature in this bacterium. It is shown here that this process is augmented by management of zinc through cytoplasmic zinc chaperones, whose syntheses are controlled by the Zur regulator. This demonstrates a new mechanism to organize zinc homeostasis through compartmentalization. Copyright © 2017 American Society for Microbiology.

The Metallophore Staphylopine Enables Staphylococcus aureus To Compete with the Host for Zinc and Overcome Nutritional Immunity.

PubMed

Grim, Kyle P; San Francisco, Brian; Radin, Jana N; Brazel, Erin B; Kelliher, Jessica L; Párraga Solórzano, Paola K; Kim, Philip C; McDevitt, Christopher A; Kehl-Fie, Thomas E

2017-10-31

During infection, the host sequesters essential nutrients, such as zinc, to combat invading microbes. Despite the ability of the immune effector protein calprotectin to bind zinc with subpicomolar affinity, Staphylococcus aureus is able to successfully compete with the host for zinc. However, the zinc importers expressed by S. aureus remain unknown. Our investigations have revealed that S. aureus possesses two importers, AdcABC and CntABCDF, which are induced in response to zinc limitation. While AdcABC is similar to known zinc importers in other bacteria, CntABCDF has not previously been associated with zinc acquisition. Concurrent loss of the two systems severely impairs the ability of S. aureus to obtain zinc and grow in zinc-limited environments. Further investigations revealed that the Cnt system is responsible for the ability of S. aureus to compete with calprotectin for zinc in culture and contributes to acquisition of zinc during infection. The cnt locus also enables S. aureus to produce the broad-spectrum metallophore staphylopine. Similarly to the Cnt transporter, loss of staphylopine severely impairs the ability of S. aureus to resist host-imposed zinc starvation, both in culture and during infection. Further investigations revealed that together staphylopine and the Cnt importer function analogously to siderophore-based iron acquisition systems in order to facilitate zinc acquisition by S. aureus Analogous systems are found in a broad range of Gram-positive and Gram-negative bacterial pathogens, suggesting that this new type of zinc importer broadly contributes to the ability of bacteria to cause infection. IMPORTANCE A critical host defense against infection is the restriction of zinc availability. Despite the subpicomolar affinity of the immune effector calprotectin for zinc, Staphylococcus aureus can successfully compete for this essential metal. Here, we describe two zinc importers, AdcABC and CntABCDF, possessed by S. aureus , the latter of which has not previously been associated with zinc acquisition. The ability of S. aureus to compete with the host for zinc is dependent on CntABCDF and the metallophore staphylopine, both in culture and during infection. These results expand the mechanisms utilized by bacteria to obtain zinc, beyond Adc-like systems, and demonstrate that pathogens utilize strategies similar to siderophore-based iron acquisition to obtain other essential metals during infection. The staphylopine synthesis machinery is present in a diverse collection of bacteria, suggesting that this new family of zinc importers broadly contributes to the ability of numerous pathogens to cause infection. Copyright © 2017 Grim et al.

The effectiveness of high dose zinc acetate lozenges on various common cold symptoms: a meta-analysis.

PubMed

Hemilä, Harri; Chalker, Elizabeth

2015-02-25

A previous meta-analysis found that high dose zinc acetate lozenges reduced the duration of common colds by 42%, whereas low zinc doses had no effect. Lozenges are dissolved in the pharyngeal region, thus there might be some difference in the effect of zinc lozenges on the duration of respiratory symptoms in the pharyngeal region compared with the nasal region. The objective of this study was to determine whether zinc acetate lozenges have different effects on the duration of common cold symptoms originating from different anatomical regions. We analyzed three randomized trials on zinc acetate lozenges for the common cold administering zinc in doses of 80-92 mg/day. All three trials reported the effect of zinc on seven respiratory symptoms, and three systemic symptoms. We pooled the effects of zinc lozenges for each symptom and calculated point estimates and 95% confidence intervals (95% CI). Zinc acetate lozenges shortened the duration of nasal discharge by 34% (95% CI: 17% to 51%), nasal congestion by 37% (15% to 58%), sneezing by 22% (-1% to 45%), scratchy throat by 33% (8% to 59%), sore throat by 18% (-10% to 46%), hoarseness by 43% (3% to 83%), and cough by 46% (28% to 64%). Zinc lozenges shortened the duration of muscle ache by 54% (18% to 89%), but there was no difference in the duration of headache and fever. The effect of zinc acetate lozenges on cold symptoms may be associated with the local availability of zinc from the lozenges, with the levels being highest in the pharyngeal region. However our findings indicate that the effects of zinc ions are not limited to the pharyngeal region. There is no indication that the effect of zinc lozenges on nasal symptoms is less than the effect on the symptoms of the pharyngeal region, which is more exposed to released zinc ions. Given that the adverse effects of zinc in the three trials were minor, zinc acetate lozenges releasing zinc ions at doses of about 80 mg/day may be a useful treatment for the common cold, started within 24 hours, for a time period of less than two weeks.

Efficacy of highly bioavailable zinc from fortified water: a randomized controlled trial in rural Beninese children.

PubMed

Galetti, Valeria; Kujinga, Prosper; Mitchikpè, Comlan Evariste S; Zeder, Christophe; Tay, Fabian; Tossou, Félicien; Hounhouigan, Joseph D; Zimmermann, Michael B; Moretti, Diego

2015-11-01

Zinc deficiency and contaminated water are major contributors to diarrhea in developing countries. Food fortification with zinc has not shown clear benefits, possibly because of low zinc absorption from inhibitory food matrices. We used a novel point-of-use water ultrafiltration device configured with glass zinc plates to produce zinc-fortified, potable water. The objective was to determine zinc bioavailability from filtered water and the efficacy of zinc-fortified water in improving zinc status. In a crossover balanced study, we measured fractional zinc absorption (FAZ) from the zinc-fortified water in 18 healthy Swiss adults using zinc stable isotopes and compared it with zinc-fortified maize porridge. We conducted a 20-wk double-blind randomized controlled trial (RCT) in 277 Beninese school children from rural settings who were randomly assigned to receive a daily portion of zinc-fortified filtered water delivering 2.8 mg Zn (Zn+filter), nonfortified filtered water (Filter), or nonfortified nonfiltered water (Pump) from the local improved supply, acting as the control group. The main outcome was plasma zinc concentration (PZn), and the 3 groups were compared by using mixed-effects models. Secondary outcomes were prevalence of zinc deficiency, diarrhea prevalence, and growth. Geometric mean (-SD, +SD) FAZ was 7-fold higher from fortified water (65.9%; 42.2, 102.4) than from fortified maize (9.1%; 6.0, 13.7; P < 0.001). In the RCT, a significant time-by-treatment effect on PZn (P = 0.026) and on zinc deficiency (P = 0.032) was found; PZn in the Zn+filter group was significantly higher than in the Filter (P = 0.006) and Pump (P = 0.025) groups. We detected no effect on diarrhea or growth, but our study did not have the duration and power to detect such effects. Consumption of filtered water fortified with a low dose of highly bioavailable zinc is an effective intervention in children from rural African settings. Large community-based trials are needed to assess the effectiveness of zinc-fortified filtered water on diarrhea and growth. These trials were registered at clinicaltrials.gov as NCT01636583 and NCT01790321. © 2015 American Society for Nutrition.

Contribution of Zinc Solubilizing Bacteria in Growth Promotion and Zinc Content of Wheat.

PubMed

Kamran, Sana; Shahid, Izzah; Baig, Deeba N; Rizwan, Muhammad; Malik, Kauser A; Mehnaz, Samina

2017-01-01

Zinc is an imperative micronutrient required for optimum plant growth. Zinc solubilizing bacteria are potential alternatives for zinc supplementation and convert applied inorganic zinc to available forms. This study was conducted to screen zinc solubilizing rhizobacteria isolated from wheat and sugarcane, and to analyze their effect on wheat growth and development. Fourteen exo-polysaccharides producing bacterial isolates of wheat were identified and characterized biochemically as well as on the basis of 16S rRNA gene sequences. Along these, 10 identified sugarcane isolates were also screened for zinc solubilizing ability on five different insoluble zinc sources. Out of 24, five strains, i.e., EPS 1 ( Pseudomonas fragi) , EPS 6 ( Pantoea dispersa) , EPS 13 ( Pantoea agglomerans) , PBS 2 ( E. cloacae) and LHRW1 ( Rhizobium sp.) were selected (based on their zinc solubilizing and PGP activities) for pot scale plant experiments. ZnCO 3 was used as zinc source and wheat seedlings were inoculated with these five strains, individually, to assess their effect on plant growth and development. The effect on plants was analyzed based on growth parameters and quantifying zinc content of shoot, root and grains using atomic absorption spectroscopy. Plant experiment was performed in two sets. For first set of plant experiments (harvested after 1 month), maximum shoot and root dry weights and shoot lengths were noted for the plants inoculated with Rhizobium sp. (LHRW1) while E. cloacae (PBS 2) increased both shoot and root lengths. Highest zinc content was found in shoots of E. cloacae (PBS 2) and in roots of P. agglomerans (EPS 13) followed by zinc supplemented control. For second set of plant experiment, when plants were harvested after three months, Pantoea dispersa (EPS 6), P. agglomerans (EPS 13) and E. cloacae (PBS 2) significantly increased shoot dry weights. However, significant increase in root dry weights and maximum zinc content was recorded for Pseudomonas fragi (EPS 1) inoculated plants, isolated from wheat rhizosphere. While maximum zinc content for roots was quantified in the control plants indicating the plant's inability to transport zinc to grains, supporting accelerated bioavailability of zinc to plant grains with zinc solubilizing rhizobacteria.

Corrigendum to “Nuclear microprobe investigation of the penetration of ultrafine zinc oxide into human skin affected by atopic dermatitis” [Nucl. Instr. Meth. B 269 (2011) 2278-2280

NASA Astrophysics Data System (ADS)

Szikszai, Z.; Kertesz, Zs.; Bodnar, E.; Borbiro, I.; Kiss, B.; Angyal, A.; Csedreki, L.; Furu, E.; Szoboszlai, Z.; Kiss, A. Z.; Hunyadi, J.

2014-11-01

The author line in the originally published version of the article is incorrect and the correct author line is as follows: Z. Szikszaia,∗, Zs. Kertesza, E. Bodnarb, I. Borbiroc, B. Kissb, A. Angyala, L. Csedrekia, E. Furua, Z. Szoboszlaia, A.Z. Kissa, J. Hunyadib

Zinc deficiency induces vascular pro-inflammatory parameters associated with NF-kappaB and PPAR signaling.

PubMed

Shen, Huiyun; Oesterling, Elizabeth; Stromberg, Arnold; Toborek, Michal; MacDonald, Ruth; Hennig, Bernhard

2008-10-01

Marginal intake of dietary zinc can be associated with increased risk of cardiovascular diseases. In the current study we hypothesized that vascular dysfunction and associated inflammatory events are activated during a zinc deficient state. We tested this hypothesis using both vascular endothelial cells and mice lacking the functional LDL-receptor gene. Zinc deficiency increased oxidative stress and NF-kappaB DNA binding activity, and induced COX-2 and E-selectin gene expression, as well as monocyte adhesion in cultured endothelial cells. The NF-kappaB inhibitor CAPE significantly reduced the zinc deficiency-induced COX-2 expression, suggesting regulation through NF-kappaB signaling. PPAR can inhibit NF-kappaB signaling, and our previous data have shown that PPAR transactivation activity requires adequate zinc. Zinc deficiency down-regulated PPARalpha expression in cultured endothelial cells. Furthermore, the PPARgamma agonist rosiglitazone was unable to inhibit the adhesion of monocytes to endothelial cells during zinc deficiency, an event which could be reversed by zinc supplementation. Our in vivo data support the importance of PPAR dysregulation during zinc deficiency. For example, rosiglitazone induced inflammatory genes (e.g., MCP-1) only during zinc deficiency, and adequate zinc was required for rosiglitazone to down-regulate pro-inflammatory markers such as iNOS. In addition, rosiglitazone increased IkappaBalpha protein expression only in zinc adequate mice. Finally, plasma data from LDL-R-deficient mice suggest an overall pro-inflammatory environment during zinc deficiency and support the concept that zinc is required for proper anti-inflammatory or protective functions of PPAR. These studies suggest that zinc nutrition can markedly modulate mechanisms of the pathology of inflammatory diseases such as atherosclerosis.

Oxidative stress in newly-hatched Chorthippus brunneus--the effects of zinc treatment during diapause, depending on the female's age and its origins.

PubMed

Augustyniak, Maria; Babczyńska, Agnieszka; Augustyniak, Michał

2011-09-01

The responses of glutathione, glutathione S-transferases (GSTs), and catalase (CAT) were determined in 1-day-old larvae of Chorthippus brunneus Thunberg, 1815, a grasshopper exposed to zinc during diapause, from unpolluted (Pilica) or polluted (Olkusz, Szopienice) sites. The aim of the work was to search for differences among populations of the insects as a result of various multistress pressures in their habitats. The question of zinc toxicity in the context of energy allocation was also considered. Zinc caused a decrease in glutathione concentration in the body of zinc-treated larvae. Significant differences between control and zinc-treated groups were confirmed for young females' progeny from Pilica and Olkusz as well as old females' progeny from Olkusz. GSTs activity was generally not influenced by zinc. It is possible that GSTs were not the most important target of zinc action. On the contrary, the influence of zinc on CAT activity was found. The increase in CAT activity after zinc treatment was similar for all studied populations. An increase in CAT activity after zinc exposure seems to be the most universal reaction. CAT activity in zinc-treated grasshoppers may explain the mechanism of zinc toxicity based on reactive oxygen forms generation. Copyright © 2011 Elsevier Inc. All rights reserved.

Heat transfer capability of solar radiation in colored roof and influence on room thermal comfort

NASA Astrophysics Data System (ADS)

Syuhada, Ahmad; Maulana, Muhammad Ilham

2018-02-01

Colored zinc is the most widely used by people in Indonesia as the roof of the building. Each color has different heat absorption capability, the higher the absorption capacity of a roof will cause high room temperature. A high temperature in the room will cause the room is not thermally comfortable for activity. Lack of public knowledge about the ability of each color to absorb heat can cause errors in choosing the color of the roof of the building so that it becomes uncomfortable regarding thermal comfort. This study examined how big the ability of each color in influencing the heat absorption on the roof of the zinc. The purpose of this study is to examine which colors are the lowest to absorb radiation heat. This research used theexperimental method. Data collected by measuring the temperature of the environment above and below the colored tin roof, starting at 11:00 am until 15:00 pm. The zinc roofs tested in this study are zinc black, red zinc, green zinc, blue zinc, brown zinc, maroon zinc, orange zinc, zinc gray, zinc color chrome and zinc white color. The study results show that black and blackish colors will absorb more heat than other colors. While the color white or close to whitish color will absorb a slight heat.

The interactive roles of zinc and calcium in mitochondrial dysfunction and neurodegeneration.

PubMed

Pivovarova, Natalia B; Stanika, Ruslan I; Kazanina, Galina; Villanueva, Idalis; Andrews, S Brian

2014-02-01

Zinc has been implicated in neurodegeneration following ischemia. In analogy with calcium, zinc has been proposed to induce toxicity via mitochondrial dysfunction, but the relative role of each cation in mitochondrial damage remains unclear. Here, we report that under conditions mimicking ischemia in hippocampal neurons - normal (2 mM) calcium plus elevated (> 100 μM) exogenous zinc - mitochondrial dysfunction evoked by glutamate, kainate or direct depolarization is, despite significant zinc uptake, primarily governed by calcium. Thus, robust mitochondrial ion accumulation, swelling, depolarization, and reactive oxygen species generation were only observed after toxic stimulation in calcium-containing media. This contrasts with the lack of any mitochondrial response in zinc-containing but calcium-free medium, even though zinc uptake and toxicity were strong under these conditions. Indeed, abnormally high, ionophore-induced zinc uptake was necessary to elicit any mitochondrial depolarization. In calcium- and zinc-containing media, depolarization-induced zinc uptake facilitated cell death and enhanced accumulation of mitochondrial calcium, which localized to characteristic matrix precipitates. Some of these contained detectable amounts of zinc. Together these data indicate that zinc uptake is generally insufficient to trigger mitochondrial dysfunction, so that mechanism(s) of zinc toxicity must be different from that of calcium. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

PubMed Central

Tran, Cuong D.; Gopalsamy, Geetha L.; Mortimer, Elissa K.; Young, Graeme P.

2015-01-01

It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease. PMID:26035248

Crosstalk between Zinc Status and Giardia Infection: A New Approach

PubMed Central

Astiazarán-García, Humberto; Iñigo-Figueroa, Gemma; Quihui-Cota, Luis; Anduro-Corona, Iván

2015-01-01

Zinc supplementation has been shown to reduce the incidence and prevalence of diarrhea; however, its anti-diarrheal effect remains only partially understood. There is now growing evidence that zinc can have pathogen-specific protective effects. Giardiasis is a common yet neglected cause of acute-chronic diarrheal illness worldwide which causes disturbances in zinc metabolism of infected children, representing a risk factor for zinc deficiency. How zinc metabolism is compromised by Giardia is not well understood; zinc status could be altered by intestinal malabsorption, organ redistribution or host-pathogen competition. The potential metal-binding properties of Giardia suggest unusual ways that the parasite may interact with its host. Zinc supplementation was recently found to reduce the rate of diarrhea caused by Giardia in children and to upregulate humoral immune response in Giardia-infected mice; in vitro and in vivo, zinc-salts enhanced the activity of bacitracin in a zinc-dose-dependent way, and this was not due to zinc toxicity. These findings reflect biological effect of zinc that may impact significantly public health in endemic areas of infection. In this paper, we shall explore one direction of this complex interaction, discussing recent information regarding zinc status and its possible contribution to the outcome of the encounter between the host and Giardia. PMID:26046395

Zinc activates damage-sensing TRPA1 ion channels.

PubMed

Hu, Hongzhen; Bandell, Michael; Petrus, Matt J; Zhu, Michael X; Patapoutian, Ardem

2009-03-01

Zinc is an essential biological trace element. It is required for the structure or function of over 300 proteins, and it is increasingly recognized for its role in cell signaling. However, high concentrations of zinc have cytotoxic effects, and overexposure to zinc can cause pain and inflammation through unknown mechanisms. Here we show that zinc excites nociceptive somatosensory neurons and causes nociception in mice through TRPA1, a cation channel previously shown to mediate the pungency of wasabi and cinnamon through cysteine modification. Zinc activates TRPA1 through a unique mechanism that requires zinc influx through TRPA1 channels and subsequent activation via specific intracellular cysteine and histidine residues. TRPA1 is highly sensitive to intracellular zinc, as low nanomolar concentrations activate TRPA1 and modulate its sensitivity. These findings identify TRPA1 as an important target for the sensory effects of zinc and support an emerging role for zinc as a signaling molecule that can modulate sensory transmission.

Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

PubMed

Maret, Wolfgang

2017-10-31

In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

Zinc in innate and adaptive tumor immunity

PubMed Central

2010-01-01

Zinc is important. It is the second most abundant trace metal with 2-4 grams in humans. It is an essential trace element, critical for cell growth, development and differentiation, DNA synthesis, RNA transcription, cell division, and cell activation. Zinc deficiency has adverse consequences during embryogenesis and early childhood development, particularly on immune functioning. It is essential in members of all enzyme classes, including over 300 signaling molecules and transcription factors. Free zinc in immune and tumor cells is regulated by 14 distinct zinc importers (ZIP) and transporters (ZNT1-8). Zinc depletion induces cell death via apoptosis (or necrosis if apoptotic pathways are blocked) while sufficient zinc levels allows maintenance of autophagy. Cancer cells have upregulated zinc importers, and frequently increased zinc levels, which allow them to survive. Based on this novel synthesis, approaches which locally regulate zinc levels to promote survival of immune cells and/or induce tumor apoptosis are in order. PMID:21087493

Association of Mood Disorders with Serum Zinc Concentrations in Adolescent Female Students.

PubMed

Tahmasebi, Kobra; Amani, Reza; Nazari, Zahra; Ahmadi, Kambiz; Moazzen, Sara; Mostafavi, Seyed-Ali

2017-08-01

Among various factors influencing mood disorders, the impact of micronutrient deficiencies has attracted a great attention. Zinc deficiency is considered to play a crucial role in the onset and progression of mood disorders in different stages of life. The main objective of this study was to assess the correlation between serum zinc levels and mood disorders in high school female students. This cross-sectional study was conducted on a random sample of 100 representative high school female students. The participants completed 24-h food recall questionnaires to assess the daily zinc intakes. Serum zinc status was assessed using flame atomic absorption spectrometry, and zinc deficiency was defined accordingly. Mood disorders were estimated by calculating the sum of two test scores including Beck's depression inventory (BDI) and hospital anxiety depression scale (HADS) tests. General linear model (GLM) and Pearson's regression test were applied to show the correlation of serum zinc levels and mood disorder scores and the correlation between zinc serum levels and BDI scores, respectively. Dietary zinc intake was higher in subjects with normal zinc concentrations than that of zinc-deficient group (p = 0.001). Serum zinc levels were inversely correlated with BDI and HADS scores (p < 0.05). Each 10 μg/dL increment in serum zinc levels led to 0.3 and 0.01 decrease in depression and anxiety scores, respectively (p < 0.05). Serum zinc levels were inversely correlated with mood disorders including depression and anxiety in adolescent female students. Increasing serum levels of zinc in female students could improve their mood disorders.

Hyperaccumulation of zinc by zinc-depleted Candida utilis grown in chemostat culture.

PubMed

Lawford, H G; Pik, J R; Lawford, G R; Williams, T; Kligerman, A

1980-01-01

The steady-state levels of zinc in Candida utilis yeast grown in continuous culture under conditions of zinc limitations are <1nmol Zn2+/mg dry weight of cells. Unlike carbon-limited cells, zinc-depleted cells from a zinc-limited chemostat possess the capacity to accumulate and store zinc at levels far in excess of the steady-state level of 4 nmol/mg dry biomass observed in carbon-limited chemostat cultures. Zinc uptake is energy-dependent and apparently undirectional since accumulated 65Zn neither exists from preloaded cells nor exchanges with cold Zn2+. The transport system exhibits a high affinity for Zn2+ (Km =.36micrM) with a Vmaxof 2.2 nmol per minute per milligram dry weight of cells. Growth during the period of the uptake assay is responsible for the apparent plateau level of 35 nmol Zn2+/mg dry weight of cells achieved after 20-30 min in the presence of 65Zn at pH 4.5 and 30 degrees C. Inhibition of growth during the uptake assay by cycloheximide results in a biphasic linear pattern of zinc accumulation where the cellular zinc is about 60 nmol/mg dry weight after 1 h. The enhanced level of accumulated zinc is not inhibtory to growth. Zinc-depleted C. utilis contains elevated amounts of polyphosphate and this anionic evidence does not allow discrimination between possible regulation of zinc homestasis either by inhibitions of zinc efflux through control of the membrane carrier or by control of the synthesis of a cytoplasmic zinc-sequestering macromolecule.

Speciation And Bioavailability Of Zinc In Amended Sediments

EPA Science Inventory

The speciation and bioavailability of zinc (Zn) in smelter-contaminated sediments was investigated as a function of phosphate (apatite) and organic amendment loading rate. Zinc species identified in preamendment sediment were zinc hydroxide-like phases, sphalerite, and zinc sorbe...

40 CFR 415.630 - Applicability; description of the zinc sulfate production subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the zinc... CATEGORY Zinc Sulfate Production Subcategory § 415.630 Applicability; description of the zinc sulfate... production of zinc sulfate. ...

40 CFR 415.630 - Applicability; description of the zinc sulfate production subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the zinc... CATEGORY Zinc Sulfate Production Subcategory § 415.630 Applicability; description of the zinc sulfate... production of zinc sulfate. ...