40 CFR 421.266 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as N) 599.900 263.700 (b) Raw material granulation... Copper 0.819 0.390 Cyanide (total) 0.128 0.051 Zinc 0.653 0.269 Combined metals 0.192 Ammonia 85.310 37....300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. PSNS for the Secondary...

40 CFR 421.266 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as N) 599.900 263.700 (b) Raw material granulation... Copper 0.819 0.390 Cyanide (total) 0.128 0.051 Zinc 0.653 0.269 Combined metals 0.192 Ammonia 85.310 37....300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. PSNS for the Secondary...

40 CFR 421.266 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as N) 599.900 263.700 (b) Raw material granulation... Copper 0.819 0.390 Cyanide (total) 0.128 0.051 Zinc 0.653 0.269 Combined metals 0.192 Ammonia 85.310 37....300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. PSNS for the Secondary...

40 CFR 421.126 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 21.150 Ammonia (as N) 6,712.000 2,951.000 (b) Subpart L—Film Stripping Wet Air Pollution Control and... filtration of film stripping solutions Copper 1.242 .592 Zinc .990 .408 Ammonia (as N) 129.300 56.840 (c....120 Zinc 58.720 24.180 Ammonia (as N) 7,674.000 3,374.000 (d) Subpart L—Precipitation and Filtration...

40 CFR 421.126 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 21.150 Ammonia (as N) 6,712.000 2,951.000 (b) Subpart L—Film Stripping Wet Air Pollution Control and... filtration of film stripping solutions Copper 1.242 .592 Zinc .990 .408 Ammonia (as N) 129.300 56.840 (c....120 Zinc 58.720 24.180 Ammonia (as N) 7,674.000 3,374.000 (d) Subpart L—Precipitation and Filtration...

40 CFR 421.265 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... smelted Copper 5.760 2.745 Cyanide (total) 0.900 0.360 Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as... Combined metals 0.192 Ammonia (as N) 85.310 37.500 (c) Spent plating solutions. PSES for the Secondary... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent Cyanide...

40 CFR 421.265 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... smelted Copper 5.760 2.745 Cyanide (total) 0.900 0.360 Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as... Combined metals 0.192 Ammonia (as N) 85.310 37.500 (c) Spent plating solutions. PSES for the Secondary... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent Cyanide...

40 CFR 421.265 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... smelted Copper 5.760 2.745 Cyanide (total) 0.900 0.360 Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as... Combined metals 0.192 Ammonia (as N) 85.310 37.500 (c) Spent plating solutions. PSES for the Secondary... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent Cyanide...

40 CFR 421.265 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... smelted Copper 5.760 2.745 Cyanide (total) 0.900 0.360 Zinc 4.590 1.890 Combined metals 1.350 Ammonia (as... Combined metals 0.192 Ammonia (as N) 85.310 37.500 (c) Spent plating solutions. PSES for the Secondary... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent Cyanide...

Impact of zinc supplementation on the improvement of ethanol tolerance and yield of self-flocculating yeast in continuous ethanol fermentation.

PubMed

Zhao, X Q; Xue, C; Ge, X M; Yuan, W J; Wang, J Y; Bai, F W

2009-01-01

The effects of zinc supplementation were investigated in the continuous ethanol fermentation using self-flocculating yeast. Zinc sulfate was added at the concentrations of 0.01, 0.05 and 0.1 g l(-1), respectively. Reduced average floc sizes were observed in all the zinc-supplemented cultures. Both the ethanol tolerance and thermal tolerance were significantly improved by zinc supplements, which correlated well with the increased ergosterol and trehalose contents in the yeast flocs. The highest ethanol concentration by 0.05 g l(-1) zinc sulfate supplementation attained 114.5 g l(-1), in contrast to 104.1 g l(-1) in the control culture. Glycerol production was decreased by zinc supplementations, with the lowest level 3.21 g l(-1), about 58% of the control. Zinc content in yeast cells was about 1.4 microMol g(-1) dry cell weight, about sixfold higher than that of control in all the zinc-supplemented cultures, and close correlation of zinc content in yeast cells with the cell viability against ethanol and heat shock treatment was observed. These studies suggest that exogenous zinc addition led to a reprogramming of cellular metabolic network, resulting in enhanced ethanol tolerance and ethanol production.

Relationship between zinc and the growth and development of young children.

PubMed

Gao, S; Tu, D N; Li, H; Cao, X; Jiang, J X; Shi, Y; Zhou, X Q; You, J B

2015-08-19

The purpose of this study was to evaluate the relationship between zinc and the growth and development of young children. The parents of 8102 young children were surveyed in person by a trained surveyor using structured questionnaires. The hair zinc concentration of the children was determined using an atomic absorption spectrophotometer. The height, weight, sitting height, and head circumference of the children were measured at follow-up visits. There was a positive correlation between hair zinc concentration and adaptive developmental quotient (ADQ; r = 0.3164, P = 0.0272) while no correlation was found between hair zinc concentration and body measurement Z scores or intelligence quotient (IQ). There was a strong positive correlation between hair zinc concentration and weight-for-age Z scores (r = 0.3618, P = 0.0416) and ADQ (r = 0.2761, P = 0.0387) in boys; there was no correlation between hair zinc concentration and body measurement Z scores, IQ, and ADQ in girls. In boys with normal hair zinc levels, ADQ was 9.58 (P = 0.0392), higher than in boys who had zinc-deficient hair. In girls with normal hair zinc levels, ADQ was 2.52 (P = 0.0296), lower than in girls with zinc-deficient hair. In conclusion, there is no significant correlation between hair zinc levels and IQ or Z scores for all body measurements in young children.

40 CFR 466.13 - New source performance standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and grease 100.0 12.60 100.0 12.60 TSS 150.0 18.91 120.0 15.12 pH (1) (1) (1) (1) English units—pounds... Nickel 2.46 0.31 1.29 0.16 Zinc 2.09 0.27 0.86 0.11 Aluminum 6.21 0.78 2.54 0.32 Iron 5.74 0.72 2.87 0.36 Oil and grease 20.48 2.58 20.48 2.58 TSS 30.72 3.87 24.58 3.10 pH (1) (1) (1) (1) 1 Within the range 7...

40 CFR 466.13 - New source performance standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and grease 100.0 12.60 100.0 12.60 TSS 150.0 18.91 120.0 15.12 pH (1) (1) (1) (1) English units—pounds... Nickel 2.46 0.31 1.29 0.16 Zinc 2.09 0.27 0.86 0.11 Aluminum 6.21 0.78 2.54 0.32 Iron 5.74 0.72 2.87 0.36 Oil and grease 20.48 2.58 20.48 2.58 TSS 30.72 3.87 24.58 3.10 pH (1) (1) (1) (1) 1 Within the range 7...

Power scaling of ultrafast laser inscribed waveguide lasers in chromium and iron doped zinc selenide.

PubMed

McDaniel, Sean A; Lancaster, Adam; Evans, Jonathan W; Kar, Ajoy K; Cook, Gary

2016-02-22

We report demonstration of Watt level waveguide lasers fabricated using Ultrafast Laser Inscription (ULI). The waveguides were fabricated in bulk chromium and iron doped zinc selenide crystals with a chirped pulse Yb fiber laser. The depressed cladding structure in Fe:ZnSe produced output powers of 1 W with a threshold of 50 mW and a slope efficiency of 58%, while a similar structure produced 5.1 W of output in Cr:ZnSe with a laser threshold of 350 mW and a slope efficiency of 41%. These results represent the current state-of-the-art for ULI waveguides in zinc based chalcogenides.

40 CFR 415.642 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Selenium (T) 0.11 0.037 Zinc (T) 0.017 0.0092 pH (1) (1) 1 Within the range 6.0 to 9.0. (b) Except as....001 Cadmium (T) 4.87×10−5 1.62×10−5 Selenium (T) 7.0×10−5 2.3×10−5 Zinc (T) 1.04×10−5 5.8×10−6 pH (1...

Epigenetic Regulation of ZBTB18 Promotes Glioblastoma Progression. | Office of Cancer Genomics

Cancer.gov

Glioblastoma (GBM) comprises distinct subtypes characterized by their molecular profile. Mesenchymal identity in GBM has been associated with a comparatively unfavorable prognosis, primarily due to inherent resistance of these tumors to current therapies. The identification of molecular determinants of mesenchymal transformation could potentially allow for the discovery of new therapeutic targets. Zinc Finger and BTB Domain Containing 18 (ZBTB18/ZNF238/RP58) is a zinc finger transcriptional repressor with a crucial role in brain development and neuronal differentiation.

Genome-wide association study for longevity with whole-genome sequencing in 3 cattle breeds.

PubMed

Zhang, Qianqian; Guldbrandtsen, Bernt; Thomasen, Jørn Rind; Lund, Mogens Sandø; Sahana, Goutam

2016-09-01

Longevity is an important economic trait in dairy production. Improvements in longevity could increase the average number of lactations per cow, thereby affecting the profitability of the dairy cattle industry. Improved longevity for cows reduces the replacement cost of stock and enables animals to achieve the highest production period. Moreover, longevity is an indirect indicator of animal welfare. Using whole-genome sequencing variants in 3 dairy cattle breeds, we carried out an association study and identified 7 genomic regions in Holstein and 5 regions in Red Dairy Cattle that were associated with longevity. Meta-analyses of 3 breeds revealed 2 significant genomic regions, located on chromosomes 6 (META-CHR6-88MB) and 18 (META-CHR18-58MB). META-CHR6-88MB overlaps with 2 known genes: neuropeptide G-protein coupled receptor (NPFFR2; 89,052,210-89,059,348 bp) and vitamin D-binding protein precursor (GC; 88,695,940-88,739,180 bp). The NPFFR2 gene was previously identified as a candidate gene for mastitis resistance. META-CHR18-58MB overlaps with zinc finger protein 717 (ZNF717; 58,130,465-58,141,877 bp) and zinc finger protein 613 (ZNF613; 58,115,782-58,117,110 bp), which have been associated with calving difficulties. Information on longevity-associated genomic regions could be used to find causal genes/variants influencing longevity and exploited to improve the reliability of genomic prediction. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antioxidants and breast cancer risk- a population-based case-control study in Canada

PubMed Central

2011-01-01

Background The effect of antioxidants on breast cancer is still controversial. Our objective was to assess the association between antioxidants and breast cancer risk in a large population-based case-control study. Methods The study population included 2,362 cases with pathologically confirmed incident breast cancer (866 premenopausal and 1,496 postmenopausal) and 2,462 controls in Canada. Intakes of antioxidants from diet and from supplementation as well as other potential risk factors for breast cancer were collected by a self-reported questionnaire. Results Compared with subjects with no supplementation, 10 years or longer supplementation of zinc had multivariable-adjusted odds ratios (OR) and 95% confidence intervals (CI) of 0.46 (0.25-0.85) for premenopausal women, while supplementation of 10 years or longer of multiple vitamin, beta-carotene, vitamin C, vitamin E and zinc had multivariable-adjusted ORs (95% CIs) of 0.74 (0.59, 0.92), 0.58 (0.36, 0.95), 0.79 (0.63-0.99), 0.75 (0.58, 0.97), and 0.47 (0.28-0.78), respectively, for postmenopausal women. No significant effect of antioxidants from dietary sources (including beta-carotene, alpha-carotene, lycopene, lutein and zeaxanthin, vitamin C, vitamin E, selenium and zinc) or from supplementation less than 10 years was observed. Conclusions This study suggests that supplementation of zinc in premenopausal women, and supplementation of multiple vitamin, beta-carotene, vitamin C, vitamin E and zinc in postmenopausal women for 10 or more years may protect women from developing breast cancer. However, we were unable to determine the overall effect of total dose or intake from both diet and supplement. PMID:21864361

Randomized controlled trial of zinc and vitamin A as co-adjuvants for the treatment of pulmonary tuberculosis.

PubMed

Lawson, Lovett; Thacher, Tom D; Yassin, Mohammed A; Onuoha, Ndubusi A; Usman, Auwal; Emenyonu, Nnamdi E; Shenkin, Alan; Davies, Peter D O; Cuevas, Luis E

2010-12-01

To assess the efficacy of weekly zinc or zinc plus retinol as adjuncts for the treatment of pulmonary tuberculosis.   Double-blind, randomized, placebo-controlled trial in 350 patients >15 years old with smear-positive tuberculosis in Nigeria (ISRCTN36636609). In addition to antituberculous treatment, patients were randomly allocated to weekly supplements of zinc (90 mg), zinc plus retinol (5000 IU) or placebos for 6 months. Primary outcomes were time to sputum smear conversion and resolution of radiographic abnormalities. After 8 weeks of treatment, 68% had achieved sputum smear conversion, and the median conversion time was 6.5 weeks. Hazard ratios (HR, 95%CI) for sputum conversion relative to the placebo group were not significant for zinc (1.07, 0.92-1.29) or zinc plus retinol (0.89, 0.76-1.07). Significant predictors of time to sputum conversion were lung abnormality score, sputum smear grade, age and serum C-reactive protein. HIV co-infection and gender were not independent predictors of time to sputum conversion. There were no significant differences between supplement groups in clinical, radiological or laboratory outcomes at 2 months or 6 months. There were 9, 9 and 2 deaths in patients receiving zinc, zinc plus retinol or placebos, respectively. Mortality in those who received zinc (HR 1.71, 0.88-3.58) or zinc plus retinol (HR 1.54, 0.78-3.26) did not differ significantly from those who received placebos. Most deaths occurred in patients co-infected with HIV.   Supplementation with zinc or zinc plus retinol did not lead to better outcomes than placebos, and caution is warranted regarding routine micronutrient supplementation, particularly in patients co-infected with HIV. © 2010 Blackwell Publishing Ltd.

Partage du zinc entre verre et phases silicatées dans des scories historiques et actuelles issues de la métallurgie du plomb dans le district de Príbram, République tchèque.

NASA Astrophysics Data System (ADS)

Ettler, Vojtěch; Johan, Zdenek; Touray, Jean-Claude; Jelínek, Emil

2000-08-01

Metallurgical slags of different ages resulting from Pb-metallurgy in the Příbram district (Czech Republic) have been studied. The chemical analysis (EPMA) of melilite, clinopyroxene, olivine and glassy matrix showed the following ZnO concentrations (in wt. %): 3.20-11.93 (melilite), 1.56 (clinopyroxene), 1.29-7.82 (olivine), 1.58-6.58 (glass). The Zn partition coefficient D = Cs / Cl between crystallized phases and coexisting glass was calculated. The values obtained are: 1.96-2.16 (melilite), 0.41 (clinopyroxene) and 0.79-1.19 (olivine). The distribution of zinc between the crystalline phases and glass depends on the phase assemblage, which reflects the blast furnace charge and temperature, as well as the cooling conditions of slags.

The effect of different mouth rinse products on intra-oral halitosis.

PubMed

Erovic Ademovski, S; Lingström, P; Renvert, S

2016-05-01

To evaluate the effect of different mouth rinses 12 h after rinsing on genuine intra-oral halitosis. Twenty-four adults with halitosis were included in a double-blind, crossover, randomized clinical trial. Halitosis was evaluated 12 h after rinsing with placebo and five mouth rinse products containing zinc acetate and chlorhexidine diacetate; zinc lactate, chlorhexidine and cetylpyridinium chloride; zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol; zinc chloride and essential oil; and chlorine dioxide using the organoleptic method and a gas chromatograph. Test periods were separated by 1 week. Hydrogen sulphide (H2 S), methyl mercaptan (MM) and the organoleptic scores (OLS) were significantly reduced 12 h following rinsing with all substances compared to placebo (P < 0.05). H2 S was more effectively reduced after rinsing with zinc acetate and chlorhexidine diacetate and zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol compared to rinsing with zinc chloride and essential oil (P < 0.05), and significantly lower values of MM were obtained after rinsing with zinc acetate and chlorhexidine diacetate compared to zinc lactate, chlorhexidine and cetylpyridinium chloride (P < 0.05). The percentage effectively treated individuals (H2 S (<112 ppb), MM (<26 ppb) and OLS score <2) varied from 58% percentage (zinc acetate and chlorhexidine diacetate) to 26% (zinc chloride and essential oil). All treatments resulted in reduction in halitosis 12 h after rinsing compared to placebo. H2 S and MM were most effectively reduced by zinc acetate and chlorhexidine diacetate. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Village-randomized clinical trial of home distribution of zinc for treatment of childhood diarrhea in rural Western kenya.

PubMed

Feikin, Daniel R; Bigogo, Godfrey; Audi, Allan; Pals, Sherri L; Aol, George; Mbakaya, Charles; Williamson, John; Breiman, Robert F; Larson, Charles P

2014-01-01

Zinc treatment shortens diarrhea episodes and can prevent future episodes. In rural Africa, most children with diarrhea are not brought to health facilities. In a village-randomized trial in rural Kenya, we assessed if zinc treatment might have a community-level preventive effect on diarrhea incidence if available at home versus only at health facilities. We randomized 16 Kenyan villages (1,903 eligible children) to receive a 10-day course of zinc and two oral rehydration solution (ORS) sachets every two months at home and 17 villages (2,241 eligible children) to receive ORS at home, but zinc at the health-facility only. Children's caretakers were educated in zinc/ORS use by village workers, both unblinded to intervention arm. We evaluated whether incidence of diarrhea and acute lower respiratory illness (ALRI) reported at biweekly home visits and presenting to clinic were lower in zinc villages, using poisson regression adjusting for baseline disease rates, distance to clinic, and children's age. There were no differences between village groups in diarrhea incidence either reported at the home or presenting to clinic. In zinc villages (1,440 children analyzed), 61.2% of diarrheal episodes were treated with zinc, compared to 5.4% in comparison villages (1,584 children analyzed, p<0.0001). There were no differences in ORS use between zinc (59.6%) and comparison villages (58.8%). Among children with fever or cough without diarrhea, zinc use was low (<0.5%). There was a lower incidence of reported ALRI in zinc villages (adjusted RR 0.68, 95% CI 0.46-0.99), but not presenting at clinic. In this study, home zinc use to treat diarrhea did not decrease disease rates in the community. However, with proper training, availability of zinc at home could lead to more episodes of pediatric diarrhea being treated with zinc in parts of rural Africa where healthcare utilization is low. ClinicalTrials.gov NCT00530829.

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.

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

Fabrication of an Organic Light-Emitting Diode from New Host π Electron Rich Zinc Complex

NASA Astrophysics Data System (ADS)

Jafari, Mohammad Reza; Janghouri, Mohammad; Shahedi, Zahra

2017-01-01

A new π electron rich zinc complex was used as a fluorescent material in organic light-emitting diodes (OLEDs). Devices with a structure of indium tin oxide/poly (3,4-ethylenedi-oxythiophene):poly(styrenesulfonate) (PEDOT: PSS) (50 nm)/polyvinylcarbazole (60 nm)/Zn: %2 porphyrin derivatives (45 nm)/Al (150 nm) were fabricated. Porphyrin derivatives accounting for 2 wt.% in the π electron rich zinc complex were used as a host. The electroluminescence (EL) spectra of porphyrin derivatives indicated a red shift, as π electron rich zinc complex EL spectra. The device (4) has also a luminance of 3420 cd/m2 and maximum efficiency of 1.58 cd/A at 15 V, which are the highest values among four devices. The result of Commission International del'Eclairage (CIE) (X, Y) coordinate and EL spectrum of device (3) indicated that it is more red shifted compared to other devices. Results of this work indicate that π electron rich zinc complex is a promising host material for high efficiency red OLEDs and has a simple structure compared to Alq3-based devices.

Lower Zinc Bioavailability May Be Related to Higher Risk of Subclinical Atherosclerosis in Korean Adults

PubMed Central

Jung, Su Kyoung; Kim, Mi-Kyung; Lee, Young-Hoon; Shin, Dong Hoon; Shin, Min-Ho; Chun, Byung-Yeol; Choi, Bo Youl

2013-01-01

Background There is a proposed link between dietary zinc intake and atherosclerosis, but this relationship remains unclear. Phytate may contribute to this relationship by influencing zinc bioavailability. Objective The aim of this study is to examine the relationship between zinc bioavailability and subclinical atherosclerosis in healthy Korean adults. Materials and Methods The present cross-sectional analysis used baseline data from the Korean multi-Rural Communities Cohort Study (MRCohort), which is a part of The Korean Genome Epidemiology Study (KoGES). A total of 5,532 subjects (2,116 men and 3,416 women) aged 40 years and older were recruited from rural communities in South Korea between 2005 and 2010. Phytate:zinc molar ratio, estimated from a food-based food frequency questionnaire (FFQ) of 106 food items, was used to determine zinc bioavailability, and carotid intima media thickness (cIMT) and pulse wave velocity (PWV) were measured to calculate the subclinical atherosclerotic index. Results We found that phytate:zinc molar ratio is positively related to cIMT in men. A higher phytate:zinc molar ratio was significantly related to an increased risk of atherosclerosis in men, defined as the 80th percentile value of cIMT (5th vs. 1st quintile, OR = 2.11, 95% CI 1.42-3.15, P for trend = 0.0009), and especially in elderly men (5th vs. 1st quintile, OR = 2.58, 95% CI 1.52-4.37, P for trend = 0.0021). We found a positive relationship between phytate:zinc molar ratio and atherosclerosis risk among women aged 65 years or younger. Phytate:zinc molar ratio was not found to be related to PWV. Conclusions Lower zinc bioavailability may be related to higher atherosclerosis risk. PMID:24223217

Preparation and Properties of Iron Doped II-VI Chalcogenides

DTIC Science & Technology

1990-03-29

Toulmin (13) have reported that the solubility limit of iron in the system Znl-xFexS was 58 mole percent iron. Papalardo and Dietz (14) studied the...of iron in zinc sulfide has previously been determined by Barton and Toulmin (13) to be 58 mole percent iron at 890OC. The samples in their studies...1988). 13. P. Barton and P. Toulmin , Economic Geology, 61, (5), 815 (1966). 14. R. Pappalardo and R. Dietz, Phys Rev., 123 (4) 1188 (1961). 15. P. W, R

Preparation, characterization and bioactivities of Athelia rolfsii exopolysaccharide-zinc complex (AEPS-zinc).

PubMed

Dong, Jinman; Li, Hongmei; Min, Weihong

2018-07-01

A new Athelia rolfsii exopolysaccharides (AEPS) were purified by Sephacryl S-300 and S-200. The physicochemical characteristics of AEPS fractions were assayed by HPGPC and GC methods. The structures of AEPS and AEPS‑zinc complex were characterized by SEM, FTIR and NMR. Moreover, the bioactivities of complex were also evaluated by experiments in vitro and in vivo. AEPSI consisted of glucose, galacturonic acid, talose, galactose, mannose and xylose, the relative contents of them were 24.74, 19.60, 33.65, 8.77, 7.97 and 5.28%, respectively. AEPSII consisted of glucose, inositol, galacturonic acid, ribitol, gluconic acid, talose and xylose, whose relative contents were 36.06, 21.21, 12.78, 11.07, 6.58, 5.45 and 6.82%, respectively. The Mw and Mn of AEPSI were 6.1324×10 4 and 1.4218×10 4 Da, those of AEPSII were 517 and 248Da. SEM observations showed that microstructures of AEPS and AEPS‑zinc complex were obviously different both in size and shape. FTIR and NMR analysis indicated that AEPS might chelate with zinc ion through hydroxy and carboxy group. In vitro experiments showed that AEPS‑zinc complex had a good bioavailability, in vivo experiments showed that it had good effect on improving zinc deficiency and antioxidant activities, which suggested that it could be used as zinc supplementation with high antioxidant activities. Copyright © 2018 Elsevier B.V. All rights reserved.

The association between dietary zinc intake and risk of pancreatic cancer: a meta-analysis.

PubMed

Li, Li; Gai, Xuesong

2017-06-30

Previous reports have suggested a potential association on dietary zinc intake with the risk of pancreatic cancer. Since the associations between different studies were controversial, we therefore conducted a meta-analysis to reassess the relationship between dietary zinc intake and pancreatic cancer risk. A comprehensive search from the databases of PubMed, Embase, Web of Science, and Medline was performed until January 31, 2017. Relative risk (RR) with 95% confidence intervals (CI) derived by using random effect model was used. Sensitivity analysis and publication bias were conducted. Our meta-analysis was based on seven studies involving 1659 cases, including two prospective cohort studies and five case-control studies. The total RR of pancreatic cancer risk for the highest versus the lowest categories of dietary zinc intake was 0.798 (0.621-0.984), with its significant heterogeneity among studies ( I 2 =58.2%, P =0.026). The average Newcastle-Ottawa scale (NOS) score was 7.29, suggesting a high quality. There was no publication bias in the meta-analysis about dietary zinc intake on the risk of pancreatic cancer. Subgroup analyses showed that dietary zinc intake could reduce the risk of pancreatic cancer in case-control studies and among American populations. In conclusion, we found that highest category of dietary zinc intake can significantly reduce the risk of pancreatic cancer, especially among American populations. © 2017 The Author(s).

Influence of thickness of zinc coating on CMT welding-brazing with AlSi5 alloy wire

NASA Astrophysics Data System (ADS)

Jin, Pengli; Wang, Zhiping; Yang, Sinan; Jia, Peng

2018-03-01

Effect of thickness of zinc coating on Cold Mattel Transfer (CMT) brazing of aluminum and galvanized steel is investigated. The thickness of zinc coating is 10 μm, 30 μm, and 60 μm, respectively. A high-speed camera was used to capture images of welding process of different specimens; the microstructure and composition analyses of the welding seam were examined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS); the mechanical properties were measured in the form of Nano-indentation experiments. The results showed that arc characteristics and metal transfer behavior were unsteady at the beginning of welding process and that became stable after two cycles of CMT. With the thickness of zinc coating thickening, arc characteristics and metal transfer behaviors were more deteriorated. Compared with 10 μm and 30 μm, clad appearance of 60 μm was straight seam edges and a smooth surface which wetting angle was 60°. Zinc-rich zone at the seam edges was formed by zinc dissolution and motel pool oscillating, and zinc content of 10 μm and 30 μm were 5.8% and 7.75%. Zinc content of 60 μm was 14.61%, and it was a belt between galvanized steel and welding seam. The thickness of intermetallic compounds layer was in the range of 1-8 μm, and it changed with the thickness of zinc coating. The average hardness of the reaction layer of 60 μm is 9.197 GPa.

Micronutrient supplementation adherence and influence on the prevalences of anemia and iron, zinc and vitamin A deficiencies in preemies with a corrected age of six months

PubMed Central

de Freitas, Brunnella Alcantara Chagas; Lima, Luciana Moreira; Moreira, Maria Elisabeth Lopes; Priore, Silvia Eloiza; Henriques, Bruno David; Carlos, Carla Fernanda Lisboa Valente; Sabino, Jusceli Souza Nogueira; do Carmo Castro Franceschini, Sylvia

2016-01-01

OBJECTIVE: To analyze adherence to the recommended iron, zinc and multivitamin supplementation guidelines for preemies, the factors associated with this adherence, and the influence of adherence on the occurrence of anemia and iron, zinc and vitamin A deficiencies. METHODS: This prospective cohort study followed 58 preemies born in 2014 until they reached six months corrected age. The preemies were followed at a referral secondary health service and represented 63.7% of the preterm infants born that year. Outcomes of interest included high or low adherence to iron, zinc and multivitamin supplementation guidelines; prevalence of anemia; and prevalences of iron, zinc, and vitamin A deficiencies. The prevalence ratios were calculated by Poisson regression. RESULTS: Thirty-eight (65.5%) preemies presented high adherence to micronutrient supplementation guidelines. At six months of corrected age, no preemie had vitamin A deficiency. The prevalences of anemia, iron deficiency and zinc deficiency were higher in the low-adherence group but also concerning in the high-adherence group. Preemies with low adherence to micronutrient supplementation guidelines were 2.5 times more likely to develop anemia and 3.1 times more likely to develop zinc deficiency. Low maternal education level increased the likelihood of nonadherence to all three supplements by 2.2 times. CONCLUSIONS: Low maternal education level was independently associated with low adherence to iron, zinc and vitamin A supplementation guidelines in preemies, which impacted the prevalences of anemia and iron and zinc deficiencies at six months of corrected age. PMID:27626474

Weatherability and Leach Resistance of Wood Impregnated with Nano-Zinc Oxide

NASA Astrophysics Data System (ADS)

Clausen, Carol A.; Green, Frederick; Nami Kartal, S.

2010-09-01

Southern pine specimens vacuum-treated with nano-zinc oxide (nano-ZnO) dispersions were evaluated for leach resistance and UV protection. Virtually, no leaching occurred in any of the nano-ZnO-treated specimens in a laboratory leach test, even at the highest retention of 13 kg/m3. However, specimens treated with high concentrations of nano-ZnO showed 58-65% chemical depletion after 12 months of outdoor exposure. Protection from UV damage after 12 months exposure is visibly obvious on both exposed and unexposed surfaces compared to untreated controls. Graying was markedly diminished, although checking occurred in all specimens. Nano-zinc oxide treatment at a concentration of 2.5% or greater provided substantial resistance to water absorption following 12 months of outdoor exposure compared to untreated and unweathered southern pine. We conclude that nano-zinc oxide can be utilized in new wood preservative formulations to impart resistance to leaching, water absorption and UV damage of wood.

Dietary zinc and iron intake and risk of depression: A meta-analysis.

PubMed

Li, Zongyao; Li, Bingrong; Song, Xingxing; Zhang, Dongfeng

2017-05-01

The associations between dietary zinc and iron intake and risk of depression remain controversial. Thus, we carried out a meta-analysis to evaluate these associations. A systematic search was performed in PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases for relevant studies up to January 2017. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random effects model. A total of 9 studies for dietary zinc intake and 3 studies for dietary iron intake were finally included in present meta-analysis. The pooled RRs with 95% CIs of depression for the highest versus lowest dietary zinc and iron intake were 0.67 (95% CI: 0.58-0.76) and 0.57 (95% CI: 0.34-0.95), respectively. In subgroup analysis by study design, the inverse association between dietary zinc intake and risk of depression remained significant in the cohort studies and cross-sectional studies. The pooled RRs (95% CIs) for depression did not substantially change in the influence analysis and subgroup analysis by adjustment for body mass index (BMI). The present meta-analysis indicates inverse associations between dietary zinc and iron intake and risk of depression. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Efficacy of zinc sulfate supplement on febrile seizure recurrence prevention in children with normal serum zinc level: A randomised clinical trial.

PubMed

Fallah, Razieh; Sabbaghzadegan, Saeideh; Karbasi, Sedighah Akhavan; Binesh, Fariba

2015-01-01

Serum zinc level might be related to pathogenesis of febrile seizure (FS). The purpose of this study was to evaluate efficacy and safety of oral zinc supplementation on FS recurrence prevention in non-zinc-deficient children. In a randomized clinical study, one hundred 18 to 60 mo old children with normal zinc level with first simple FS were referred to Shahid Sadoughi Hospital, Yazd, Iran from May 2012 to June 2013, were randomly assigned to two groups to receive 2 mg/kg/d zinc sulfate for six consecutive months or placebo as control group and were followed up for 1 y for FS recurrence. 41 girls and 59 boys with mean age of 2.47 ± 1.01 y were evaluated. Race, mean weight, height and body fat were similar in both groups. FS recurrence occurred in 19 children (38%) in the control group [95% confidence interval (CI): 19.45%-53.95%] and in 11 children (22%) in the zinc sulfate (95% CI: 57.47%-89.13%) groups, respectively; and the zinc group had lower FS recurrence (P = 0.03). The mean serum zinc level before intervention was lower in children with FS recurrence (72.43 ± 14.58 μg/dL versus 96.33 ± 12.69 μg/dL, P = 0.04). Gastrointestinal side effects (vomiting in five children, heartburn in two children and abdominal pain in one child) were seen in 16% of the zinc group and vomiting occurred in two children (4%) in control group and frequency of adverse events was similar in the two groups (P = 0.1). Zinc supplementation should be considered as effective and safe in prevention of FS recurrence. Copyright © 2015 Elsevier Inc. All rights reserved.

Improvement in degradability of 58s glass scaffolds by ZnO and β-TCP modification

PubMed Central

Shuai, Cijun; Cao, Yiyuan; Dan, Gao; Gao, Chengde; Feng, Pei; Wu, Ping

2016-01-01

ABSTRACT 58s bioactive glass shows great potential for bone defects repair. However, at early repairing stage, the degradation rate of 58s glass is too fast due to the fast ion-exchange. At later repairing stage, the degradation rate of 58s glass is too slow due to the high dense mineral layer. In this work, Zinc oxide (ZnO) and β-tricalcium phosphate (β-TCP) were introduced into 58s glass bone scaffolds to improve the degradability. The results showed that ZnO could decrease the degradation rate and promote the stability of 58s glass at early repairing stage. Moreover, the presence of β-TCP appeared to increase the degradation rate at a later stage of repairing. Furthermore, in vitro biocompatibility study, carried out using human osteoblast-like cells (MG63), demonstrated that ZnO and β-TCP enhanced cell attachment and proliferation. The study provided a reference for further research in bone tissue engineering. PMID:27710432

High dietary zinc feeding promotes persistence of multi-resistant E. coli in the swine gut

PubMed Central

Guenther, Sebastian; Pieper, Robert; Kalisch, Martin; Bednorz, Carmen; Wieler, Lothar H.

2018-01-01

High levels of zinc oxide are used frequently as feed additive in pigs to improve gut health and growth performance and are still suggested as an alternative to antimicrobial growth promoters. However, we have recently described an increase of multi-resistant E. coli in association to zinc feeding in piglets. This previous study focused on clonal diversity of E. coli, observing the effect on multi-resistant strains by chance. To shed further light into this highly important topic and falsify our previous findings, we performed a zinc pig feeding trial where we specifically focused on in-depth analysis of antimicrobial resistant E. coli. Under controlled experimental conditions, piglets were randomly allocated to a high dietary zinc (zinc group) and a background zinc feeding group (control group). At different ages samples were taken from feces, digesta, and mucosa and absolute E. coli numbers were determined. A total of 2665 E. coli isolates were than phenotypically tested for antimicrobial resistance and results were confirmed by minimum inhibitory concentration testing for random samples. In piglets fed with high dietary zinc, we detected a substantial increase of multi-resistant E. coli in all gut habitats tested, ranging from 28.9–30.2% multi-resistant E. coli compared to 5.8–14.0% in the control group. This increase was independent of the total number of E. coli. Interestingly, the total amount of the E. coli population decreased over time. Thus, the increase of the multi-resistant E. coli populations seems to be linked with persistence of the resistant population, caused by the influence of high dietary zinc feeding. In conclusion, these findings corroborate our previous report linking high dietary zinc feeding of piglets with the occurrence of antimicrobial resistant E. coli and therefore question the feeding of high dietary zinc oxide as alternative to antimicrobial growth promoters. PMID:29373597

Changes in zinc status and zinc transporters expression in whole blood of patients with Systemic Inflammatory Response Syndrome (SIRS).

PubMed

Florea, Daniela; Molina-López, Jorge; Hogstrand, Christer; Lengyel, Imre; de la Cruz, Antonio Pérez; Rodríguez-Elvira, Manuel; Planells, Elena

2018-09-01

Critically ill patients develop severe stress, inflammation and a clinical state that may raise the utilization and metabolic replacement of many nutrients and especially zinc, depleting their body reserves. This study was designed to assess the zinc status in critical care patients with systemic inflammatory response syndrome (SIRS), comparing them with a group of healthy people, and studying the association with expression of zinc transporters. This investigation was a prospective, multicentre, comparative, observational and analytic study. Twelve critically ill patients from different hospitals and 12 healthy subjects from Granada, Spain, all with informed consent were recruited. Data on daily nutritional assessment, ICU severity scores, inflammation, clinical and nutritional parameters, plasma and blood cell zinc concentrations, and levels of transcripts for zinc transporters in whole blood were taken at admission and at the seventh day of the ICU stay. Zinc levels on critical ill patient are diminish comparing with the healthy control (HS: 0.94 ± 0.19; CIPF: 0.67 ± 0.16 mg/dL). The 58% of critical ill patients showed zinc plasma deficiency at beginning of study while 50.0% of critical ill after 7 days of ICU stay. ZnT7, ZIP4 and ZIP9 were the zinc transporters with highest expression in whole blood. In general, all zinc transporters were significantly down-regulated (P < 0.05) in the critical ill population at admission in comparison with healthy subjects. Severity scores and inflammation were significantly associated (P < 0.05) with zinc plasma levels, and zinc transporters ZIP3, ZIP4, ZIP8, ZnT6, ZnT7. Expression of 11 out of 24 zinc transporters was analysed, and ZnT1, ZnT4, ZnT5 and ZIP4, which were downregulated by more than 3-fold in whole blood of patients. In summary, in our study an alteration of zinc status was related with the severity-of-illness scores and inflammation in critical ill patients since admission in ICU stay. SIRS caused a general shut-down of expression of zinc transporters in whole blood. That behavior was associated with severity and inflammation of patients at ICU admission regardless zinc status. We conclude that zinc transporters in blood might be useful indicators of severity of systemic inflammation and outcome for critically ill patients. Copyright © 2017 Elsevier GmbH. All rights reserved.

40 CFR 466.33 - New source performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 6.13 0.79 Oil and grease 97.24 12.60 97.24 12.60 TSS 145.86 18.91 116.69 15.12 pH (1) (1) (1) (1... 0.03 0.18 0.20 Nickel 1.10 0.14 0.74 0.10 Zinc 2.03 0.27 0.84 0.11 Aluminum 6.03 0.78 2.47 0.32 Iron 2.45 0.32 1.26 0.16 Oil and grease 19.92 2.58 19.92 2.58 TSS 29.88 3.87 23.90 3.10 pH (1) (1) (1) (1...

40 CFR 466.33 - New source performance standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 6.13 0.79 Oil and grease 97.24 12.60 97.24 12.60 TSS 145.86 18.91 116.69 15.12 pH (1) (1) (1) (1... 0.03 0.18 0.20 Nickel 1.10 0.14 0.74 0.10 Zinc 2.03 0.27 0.84 0.11 Aluminum 6.03 0.78 2.47 0.32 Iron 2.45 0.32 1.26 0.16 Oil and grease 19.92 2.58 19.92 2.58 TSS 29.88 3.87 23.90 3.10 pH (1) (1) (1) (1...

40 CFR 466.33 - New source performance standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 6.13 0.79 Oil and grease 97.24 12.60 97.24 12.60 TSS 145.86 18.91 116.69 15.12 pH (1) (1) (1) (1... 0.03 0.18 0.20 Nickel 1.10 0.14 0.74 0.10 Zinc 2.03 0.27 0.84 0.11 Aluminum 6.03 0.78 2.47 0.32 Iron 2.45 0.32 1.26 0.16 Oil and grease 19.92 2.58 19.92 2.58 TSS 29.88 3.87 23.90 3.10 pH (1) (1) (1) (1...

Comparing the Effects of Zinc Sulfate, Calcium Pantothenate, Their Combination and Minoxidil Solution Regimens on Controlling Hair Loss in Women: A Randomized Controlled Trial.

PubMed

Siavash, Mansour; Tavakoli, Fereshteh; Mokhtari, Fatemeh

2017-01-01

This study was conducted to evaluate the combination of oral supplements with 2% minoxidil solution in four groups of women with hair loss. A prospective, randomized controlled trial was conducted from July to December 2016 in dermatology clinics affiliated to Isfahan University of Medical Sciences. A total of 73, 15-45-year-old, women with hair loss participated in this 4-month study. Simple randomization using Random Allocation Software was done to put the participants in four groups to receive coadministration of zinc sulfate and calcium pantothenate, zinc sulfate, calcium pantothenate, and 2% minoxidil solution. The primary endpoint was the change in hair density and diameter measured by dermatoscope. Secondary endpoints included the researcher's evaluation, dermatologist's opinion - which was blinded to the study - from comparing the participants' photographs before and after treatment and finally, overall changes in hair density measured by participants' self-assessment. Seventy-three women participated in this study. Primary hair count and thickness were 118.5 ± 10 hairs/cm 2 and 58.8 ± 5.8 μ that changed to 124 ± 11 hairs/cm 2 and 62.3 ± 4.3 μ respectively ( P < 0.001) which in the zinc plus pantothenate group these changes were from 118.6 ± 9.9 hairs/cm 2 to 121.9 ± 11.1 hairs/cm 2 ( P = 0.042) and from 62.2 ± 6.6 μ to 64.0 ± 5.0 μ ( P = 0.126), respectively. Hair density increments were more obvious in the minoxidil group, and hair thickness increments were more obvious in pantothenate group. Participants' satisfaction was 85% in the combination therapy which was more than other groups. Participants' satisfaction, author's and blind dermatologist's opinion showed a significant correlation ( P = 0.0001). Based on the participants' satisfaction, the combination of zinc sulfate and calcium pantothenate when administered in a pulse therapy way could be a good choice for hair loss controlling in initial stages.

Mode of VAMP Substrate Recognition and Inhibition of Clostridium botulinum Neurotoxin F

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

Agarwal, R.; Schmidt, J; Stafford, R

2009-01-01

Clostridium botulinum neurotoxins (BoNTs) cleave neuronal proteins responsible for neurotransmitter release, causing the neuroparalytic disease botulism. BoNT serotypes B, D, F and G cleave and inactivate vesicle-associated membrane protein (VAMP), each at a unique peptide bond. The specificity of BoNTs depends on the mode of substrate recognition. We have investigated the mechanism of substrate recognition of BoNT F by determining the crystal structures of its complex with two substrate-based inhibitors, VAMP 22-58/Gln58D-cysteine and 27-58/Gln58D-cysteine. The inhibitors bind to BoNT F in the canonical direction (as seen for BoNTs A and E substrates) but are positioned specifically via three major exositesmore » away from the active site. The cysteine sulfur of the inhibitors interacts with the zinc and exists as sulfinic acid in the inhibitor VAMP 27-58/Gln58D-cysteine. Arg133 and Arg171, which form part of two separate exosites, are crucial for substrate binding and catalysis.« less

Low zinc serum levels and high blood lead levels among school-age children in coastal area

NASA Astrophysics Data System (ADS)

Pramono, Adriyan; Panunggal, Binar; Rahfiludin, M. Zen; Swastawati, Fronthea

2017-02-01

The coverage of environmental lead toxicant was quiet wide. Lead exposure recently has been expected to be associated with zinc deficiency and blood indices disturbance. Emphasizing on children, which could absorb more than 50 % of lead that enters the body. Lead became the issue on the coastal area due to it has polluted the environment and waters as the source of fisheries products. This was a cross sectional study to determined nutritional status, blood lead levels, zinc serum levels, blood indices levels, fish intake among school children in coastal region of Semarang. This study was carried out on the school children aged between 8 and 12 years old in coastal region of Semarang. Nutritional status was figured out using anthropometry measurement. Blood lead and zinc serum levels were analyzed using the Atomic Absorbent Spectrophotometry (AAS) at a wavelength of 213.9 nm for zinc serum and 283.3 nm for blood lead. Blood indices was measured using auto blood hematology analyzer. Fish intake was assessed using 3-non consecutive days 24-hours food recall. The children had high lead levels (median 34.86 μg/dl, range 11.46 - 58.86 μg/dl) compared to WHO cut off. Zinc serum levels was low (median 18.10 μg/dl, range 10.25 - 41.39 μg/dl) compared to the Joint WHO/UNICEF/IAEA/IZiNCG cut off. Approximately 26.4% of children were anemic. This study concluded that all school children had high blood lead levels, low zinc serum, and presented microcytic hypochromic anemia. This phenomenon should be considered as public health concern.

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

Baiden, H.N.; Ercanli-Huffman, F.G.

Bioavailability of zinc from sweet potato (SP) roots and leaves were determined, by extrinsic labeling technique, in rats fed control and zinc deficient diets. Weanling male Sprague Dawley (SD) rats (60-75g) were divided into 4 groups, and fed laboratory chow, a control diet (ad libitum and pair fed) and a zinc deficient diet, for 4 weeks. Each group then was divided into at least 2 sub groups, containing 6 rats, which were intubated with one of 3 tubing solutions extrinsically labeled with /sup 65/Zn; baked sweet potato roots (BSPR), raw sweet potato leaves (RSPL) and cooked sweet potato leaves (CSPL).more » Five hours after intubation the rats were sacrificed, blood, liver, testes, spleen, heart, brain, thymus and lungs were removed. Feces, urine, and GI tract contents were collected and their /sup 65/Zn activity was determined in a gamma counter. In all treatment groups zinc bioavailability from BSPR, RSPL or CSPL were not significantly different. Zinc deficient rats absorbed significantly more (P < 0.01) /sup 65/Zn (86-90% of the dose), regardless of type of tubing solution than the pairfed or control animals (35-58% of the dose). The highest retention of /sup 65/Zn was found in the liver (12-20% of absorbed dose), GI tract (6-17% of absorbed dose), kidney (2-8% of absorbed dose), and blood (1-5% of absorbed dose). The lowest retention was found in the brain, heart, thymus and testes. (< 1% of absorbed dose).« less

40 CFR 421.263 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Ammonia (as N) 599.900 263.700 (b) Raw material granulation. BAT Limitations for the Secondary Precious....051 Zinc 0.653 0.269 Combined metals 0.192 Palladium 0.064 Platinum 0.064 Ammonia (as N) 85.310 37.500... Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. BAT Limitations...

40 CFR 421.263 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Ammonia (as N) 599.900 263.700 (b) Raw material granulation. BAT Limitations for the Secondary Precious....051 Zinc 0.653 0.269 Combined metals 0.192 Palladium 0.064 Platinum 0.064 Ammonia (as N) 85.310 37.500... Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. BAT Limitations...

40 CFR 421.263 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Ammonia (as N) 599.900 263.700 (b) Raw material granulation. BAT Limitations for the Secondary Precious....051 Zinc 0.653 0.269 Combined metals 0.192 Palladium 0.064 Platinum 0.064 Ammonia (as N) 85.310 37.500... Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. BAT Limitations...

40 CFR 421.263 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Ammonia (as N) 599.900 263.700 (b) Raw material granulation. BAT Limitations for the Secondary Precious....051 Zinc 0.653 0.269 Combined metals 0.192 Palladium 0.064 Platinum 0.064 Ammonia (as N) 85.310 37.500... Combined metals 0.300 Ammonia (as N) 133.300 58.600 (d) Spent cyanide stripping solutions. BAT Limitations...

Causes of toxicity in stormwater runoff from sawmills

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

Bailey, H.C.; Elphick, J.R.; Potter, A.

1999-07-01

Samples of stormwater runoff from nine sawmills in British Columbia, Canada, were tested for acute toxicity with juvenile rainbow trout over a 23-month period. Forty-two of the 58 samples tested exhibited toxicity. Causes of toxicity were investigated using toxicity identification evaluation techniques. Toxicity was attributed to divalent cations, particularly zinc, in 32 of the samples. The low hardness associated with most of the samples increased the potential for metal toxicity. For example, the LC50 of zinc was 14 {micro}g/L at a hardness of 5 mg/L. Toxicity in the remaining samples was largely attributed to tannins and lignins and was associatedmore » with areas of bulk log handling. No evidence was found to indicate that antisapstain chemicals applied to freshly cut wood contributed to toxicity.« less

The prokaryotic zinc-finger: structure, function and comparison with the eukaryotic counterpart.

PubMed

Malgieri, Gaetano; Palmieri, Maddalena; Russo, Luigi; Fattorusso, Roberto; Pedone, Paolo V; Isernia, Carla

2015-12-01

Classical zinc finger (ZF) domains were thought to be confined to the eukaryotic kingdom until the transcriptional regulator Ros protein was identified in Agrobacterium tumefaciens. The Ros Cys2 His2 ZF binds DNA in a peculiar mode and folds in a domain significantly larger than its eukaryotic counterpart consisting of 58 amino acids (the 9-66 region) arranged in a βββαα topology, and stabilized by a conserved, extensive, 15-residue hydrophobic core. The prokaryotic ZF domain, then, shows some intriguing new features that make it interestingly different from its eukaryotic counterpart. This review will focus on the prokaryotic ZFs, summarizing and discussing differences and analogies with the eukaryotic domains and providing important insights into their structure/function relationships. © 2015 FEBS.

Yacon effects in immune response and nutritional status of iron and zinc in preschool children.

PubMed

Vaz-Tostes, Maria das Graças; Viana, Mirelle Lomar; Grancieri, Mariana; Luz, Tereza Cecília dos Santos; Paula, Heberth de; Pedrosa, Rogério Graça; Costa, Neuza Maria Brunoro

2014-06-01

The aim of this study was to evaluate the effect of yacon flour on iron and zinc nutritional status and immune response biomarkers in preschool children. Preschool children ages 2 to 5 y were selected from two nurseries and were placed into a control group (n = 58) or a yacon group (n = 59). The yacon group received yacon flour in preparations for 18 wk at a quantity to provide 0.14 g of fructooligosaccharides/kg of body weight daily. Anthropometric parameters were measured before and after the intervention and dietary intake was measured during the intervention. To assess iron and zinc status, erythrograms, serum iron, ferritin, and plasma, and erythrocyte zinc were evaluated. Systemic immune response was assessed by the biomarkers interleukin IL-4, IL-10, IL-6, and tumor necrosis factor-alfa (TNF-α). Intestinal immune response was analyzed by secretory IgA (sIgA) levels before and after the intervention. Statistical significance was evaluated using the paired t test (α = 5%). Before and after the study, the children presented a high prevalence of overweight and an inadequate dietary intake of zinc and fiber. The yacon group presented with lower hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration at the end of the study (P < 0.05). Erythrocyte zinc was reduced in both groups at the end of the study (P < 0.05). Yacon intake increased the serum levels of IL-4 and fecal sIgA (P < 0.05). The control group had lower serum TNF-α after the study period (P < 0.05). Yacon improved intestinal immune response but demonstrated no effect on the nutritional status of iron and zinc in preschool children. Copyright © 2014 Elsevier Inc. All rights reserved.

Characterization and in vitro bioactivity of zinc-containing bioactive glass and glass-ceramics.

PubMed

Du, Rui Lin; Chang, Jiang; Ni, Si Yu; Zhai, Wan Yin; Wang, Jun Ying

2006-04-01

Zinc-containing glass is prepared by the substitution of CaO in 58S bioactive glass with 0.5 and 4 wt% ZnO, and glass-ceramics are obtained by heat-treating the glass at 1,200 C. The bending strength and in vitro bioactivity of the glass and glass-ceramics are evaluated. The results indicate that Zn promotes the crystallization of SiO(2) and wollastonite in glass-ceramics, and proper crystallization can enhance the bending strength of the glass-ceramic. The in vitro results show that ZnO in glass retards the hydroxyapatite (HA) nucleation at the initial stage of simulated body fluid (SBF) soaking, but does not affect the growth of HA after long periods of soaking, and the ionic products of 58S4Z glass can stimulate the proliferation of osteoblast at certain concentrations. Osteoblasts attach well on both glass samples and glass-ceramic samples, but the high Si ion concentration released from glass samples restrains the proliferation of osteoblasts after 3 days of culture. In contrast, osteoblasts show good proliferation on glass-ceramic samples, and ZnO in glass-ceramics promotes the proliferation rate. The results in this study suggest that the glass and glass-ceramics with different ZnO content might be used as bioactive bone implant materials in different applications.

Zinc for the common cold.

PubMed

Singh, Meenu; Das, Rashmi R

2011-02-16

The common cold is one of the most widespread illnesses and is a leading cause of visits to the doctor and absenteeism from school and work. Trials conducted since 1984 investigating the role of zinc for the common cold symptoms have had mixed results. Inadequate treatment masking and reduced bioavailability of zinc from some formulations have been cited as influencing results. To assess the effect of zinc on common cold symptoms. We searched CENTRAL (2010, Issue 2) which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to May week 3, 2010) and EMBASE (1974 to June 2010). Randomised, double-blind, placebo-controlled trials using zinc for at least five consecutive days to treat, or for at least five months to prevent the common cold. Two review authors independently extracted data and assessed trial quality. We included 13 therapeutic trials (966 participants) and two preventive trials (394 participants). Intake of zinc is associated with a significant reduction in the duration (standardized mean difference (SMD) -0.97; 95% confidence interval (CI) -1.56 to -0.38) (P = 0.001), and severity of common cold symptoms (SMD -0.39; 95% CI -0.77 to -0.02) (P = 0.04). There was a significant difference between the zinc and control group for the proportion of participants symptomatic after seven days of treatment (OR 0.45; 95% CI 0.2 to 1.00) (P = 0.05). The incidence rate ratio (IRR) of developing a cold (IRR 0.64; 95% CI 0.47 to 0.88) (P = 0.006), school absence (P = 0.0003) and prescription of antibiotics (P < 0.00001) was lower in the zinc group. Overall adverse events (OR 1.59; 95% CI 0.97 to 2.58) (P = 0.06), bad taste (OR 2.64; 95% CI 1.91 to 3.64) (P < 0.00001) and nausea (OR 2.15; 95% CI 1.44 to 3.23) (P = 0.002) were higher in the zinc group. Zinc administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people. When supplemented for at least five months, it reduces cold incidence, school absenteeism and prescription of antibiotics in children. There is potential for zinc lozenges to produce side effects. In view of this and the differences in study populations, dosages, formulations and duration of treatment, it is difficult to make firm recommendations about the dose, formulation and duration that should be used.

Inclusion of Guava Enhances Non-Heme Iron Bioavailability but Not Fractional Zinc Absorption from a Rice-Based Meal in Adolescents12

PubMed Central

Nair, Krishnapillai Madhavan; Brahmam, Ginnela N.V.; Radhika, Madhari S.; Dripta, Roy Choudhury; Ravinder, Punjal; Balakrishna, Nagalla; Chen, Zhensheng; Hawthorne, Keli M.; Abrams, Steven A.

2013-01-01

Assessing the bioavailability of non-heme iron and zinc is essential for recommending diets that meet the increased growth-related demand for these nutrients. We studied the bioavailability of iron and zinc from a rice-based meal in 16 adolescent boys and girls, 13–15 y of age, from 2 government-run residential schools. Participants were given a standardized rice meal (regular) and the same meal with 100 g of guava fruit (modified) with 57Fe on 2 consecutive days. A single oral dose of 58Fe in orange juice was given at a separate time as a reference dose. Zinc absorption was assessed by using 70Zn, administered intravenously, and 67Zn given orally with meals. The mean hemoglobin concentration was similar in girls (129 ± 7.8 g/L) and boys (126 ± 7.1 g/L). There were no sex differences in the indicators of iron and zinc status except for a higher hepcidin concentration in boys (P < 0.05). The regular and modified meals were similar in total iron (10–13 mg/meal) and zinc (2.7 mg/meal) content. The molar ratio of iron to phytic acid was >1:1, but the modified diet had 20 times greater ascorbic acid content. The absorption of 57Fe from the modified meal, compared with regular meal, was significantly (P < 0.05) greater in both girls (23.9 ± 11.2 vs. 9.7 ± 6.5%) and boys (19.2 ± 8.4 vs. 8.6 ± 4.1%). Fractional zinc absorption was similar between the regular and modified meals in both sexes. Hepcidin was found to be a significant predictor of iron absorption (standardized β = −0.63, P = 0.001, R2 = 0.40) from the reference dose. There was no significant effect of sex on iron and zinc bioavailability from meals. We conclude that simultaneous ingestion of guava fruit with a habitual rice-based meal enhances iron bioavailability in adolescents. PMID:23596161

Selectivity sequences and sorption capacities of phosphatic clay and humus rich soil towards the heavy metals present in zinc mine tailing.

PubMed

Chaturvedi, Pranav Kumar; Seth, Chandra Shekhar; Misra, Virendra

2007-08-25

Sorption efficacy of phosphatic clay and humus rich soil alone and on combination were tested towards heavy metals present in zinc mine tailing (Zawar Zinc Mine), Udaipur (India). Characterization of the zinc mine tailing sample indicated the presence of Pb, Cu, Zn and Mn in the concentration of 637, 186, 720 and 577microg(-1), respectively. For sorption efficacy, the zinc mine tailing soil were properly amended with phosphatic clay and humus rich soil separately and in combination and leachability study was performed by batch experiment at different pH range from 3 to 9. The data showed that the percent leachability of heavy metal in non-amended soil was 75-90%. After amendment with phosphatic clay percent leachability of heavy metals became 35-45%. Further, the addition of humus soil to phosphatic clay decreased the percent leachability up to 5-15% at all tested pH. Column leachability experiment was performed to evaluate the rate of leachability. The shape of cumulative curves of Pb, Cu, Zn and Mn showed an increase in its concavity in following order: PbCu>Zn>Mn. Further, Langmuir isotherms applied for the sorption studies indicated that phosphatic clay in the presence of humus soil had high affinity for Pb followed by Cu, Zn and Mn, with sorption capacities (b) 139.94, 97.02, 83.32 and 67.58microgg(-1), respectively.

Heavy metal levels of pasture grasses in metropolitan area

NASA Astrophysics Data System (ADS)

Luilo, G. B.; Othman, O. C.

2003-05-01

Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study bas been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06-2.58 ± 0.15), Mn (41.5 ± 13.6-345.0 ± 124.3), Pb (1.15 ± 0.64-25.53 ± 1.29) and Zn (25.97 ± 3.69-95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.

The contribution of dairy products to micronutrient intake in the Netherlands.

PubMed

Vissers, Pauline A J; Streppel, Martinette T; Feskens, Edith J M; de Groot, Lisette C P G M

2011-10-01

To assess the contribution of dairy products to the intake of various vitamins and minerals in several life stages in the Dutch population. Data from 3 Dutch Food Consumption Surveys and the Leiden Longevity Study were used to estimate the contribution of dairy products--as percentage of total intake--to the intake of iron, copper, selenium, zinc, calcium, folic acid, vitamin D, vitamin C, and vitamin B(12). In young children, dairy products contributed substantially to the intake of calcium (73%), selenium (21%), iron (8%), zinc (39%), copper (12%), folic acid (24%), vitamin C (18%), vitamin D (16%), and vitamin B(12) (58%). Of all dairy products, milk contributed the most to the intake of these nutrients. In adults and elderly subjects, the contribution of dairy products to total micronutrient intake was 65%-68% for calcium, 18%-19% for selenium, 3%-4% for iron, 28%-31% for zinc, 6%-7% for copper, 17%-19% for folic acid, 10%-14% for vitamin C, 11%-16% for vitamin D, and 44%-46% for vitamin B(12). Milk as well as cheese contributed the most to the intake of these nutrients. Dairy products are an important source of vitamins and minerals in the Dutch population. Dairy products, especially milk and cheese, contribute substantially to the intake of calcium, selenium, zinc, and vitamin B(12).

40 CFR 421.264 - Standards of performance for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Ammonia (as N) 599.900 263.700 Total suspended solids 67.500 54.000 pH (1) (1) 1 Within the range of 7.5....269 Combined metals 0.192 Ammonia (as N) 85.310 37.500 Total suspended solids 9.600 7.680 pH (1) (1) 1... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 Total suspended solids 15...

40 CFR 421.264 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Ammonia (as N) 599.900 263.700 Total suspended solids 67.500 54.000 pH (1) (1) 1 Within the range of 7.5....269 Combined metals 0.192 Ammonia (as N) 85.310 37.500 Total suspended solids 9.600 7.680 pH (1) (1) 1... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 Total suspended solids 15...

40 CFR 421.264 - Standards of performance for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Ammonia (as N) 599.900 263.700 Total suspended solids 67.500 54.000 pH (1) (1) 1 Within the range of 7.5....269 Combined metals 0.192 Ammonia (as N) 85.310 37.500 Total suspended solids 9.600 7.680 pH (1) (1) 1... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 Total suspended solids 15...

40 CFR 421.264 - Standards of performance for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Ammonia (as N) 599.900 263.700 Total suspended solids 67.500 54.000 pH (1) (1) 1 Within the range of 7.5....269 Combined metals 0.192 Ammonia (as N) 85.310 37.500 Total suspended solids 9.600 7.680 pH (1) (1) 1... 0.080 Zinc 1.020 0.420 Combined metals 0.300 Ammonia (as N) 133.300 58.600 Total suspended solids 15...

Zinc supplementation for improving glucose handling in pre-diabetes: A double blind randomized placebo controlled pilot study.

PubMed

Islam, Md Rafiqul; Attia, John; Ali, Liaquat; McEvoy, Mark; Selim, Shahjada; Sibbritt, David; Akhter, Ayesha; Akter, Shahnaz; Peel, Roseanne; Faruque, Omar; Mona, Tazreen; Lona, Hafiza; Milton, Abul Hasnat

2016-05-01

There are a number of studies showing that zinc supplementation may improve glucose handling in people with established diabetes. We sought to investigate whether this zinc-dependent improvement in glucose handling could potentially be harnessed to prevent the progression of pre-diabetes to diabetes. In this double-blind randomized placebo-controlled trial, we determined participants' fasting blood glucose levels, (FBG) and Homeostasis Model Assessment (HOMA) parameters (beta cell function, insulin sensitivity and insulin resistance) at baseline and after 6 months of zinc supplementation. The Bangladesh Institute of Health Sciences Hospital (BIHS) (Mirpur, Dhaka, Bangladesh) database was used to identify 224 patients with prediabetes, of whom 55 met the inclusion criteria and agreed to participate. The participants were randomized either to the intervention or control group using block randomization. The groups received either 30mg zinc sulphate dispersible tablet or placebo, once daily for six months. After six months, the intervention group significantly improved their FBG concentration compared to the placebo group (5.37±0.20mmol/L vs 5.69±0.26, p<0.001) as well as compared to their own baseline (5.37±0.20mmol/L vs 5.8±0.09, p<0.001). Beta cell function, insulin sensitivity and insulin resistance all showed a statistically significant improvement as well. To our knowledge this is the first trial to show an improvement in glucose handling using HOMA parameters in participants with prediabetes. Larger randomized controlled trials are warranted to confirm these findings and to explore clinical endpoints. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The association of time in the US and diet during pregnancy in low-income women of Mexican descent.

PubMed

Harley, Kim; Eskenazi, Brenda; Block, Gladys

2005-03-01

This study compared nutritional intake during pregnancy among women of Mexican descent according to country of birth (US vs. Mexico) and, for Mexico-born women, according to number of years lived in the US (or= 11 years). A 72-item food frequency questionnaire (FFQ) was used to assess dietary intake in 474 pregnant Mexico-born immigrants and US-born Mexican-Americans. Mexico-born women had significantly higher intakes of calories (P = 0.02), fibre (P < 0.001), vitamin A (P < 0.001), vitamin C (P = 0.03), vitamin E (P < 0.01), folate (P < 0.01), calcium (P < 0.001) and zinc (P = 0.02) from their diets than US-born women. Intakes of all nutrients except vitamin C and zinc remained significantly higher in Mexico-born women when nutrients from both diet and vitamin supplements were considered. Among Mexico-born women, increasing years of residence in the US was associated with lower intake of calories (P(trend) < 0.01), fibre (P(trend) < 0.01), folate (P(trend) = 0.03), iron (P(trend) = 0.05) and zinc (P(trend) = 0.03), although only the trend for iron remained significant when vitamin supplement sources were included. A large percentage of women had inadequate intake of vitamin E (58%), folate (61%), iron (77%) and zinc (47%) from their diets during pregnancy and these rates were higher in US-born women than Mexico-born women.

Heavy metals in soil at a waste electrical and electronic equipment processing area in China.

PubMed

Gu, Weihua; Bai, Jianfeng; Yao, Haiyan; Zhao, Jing; Zhuang, Xuning; Huang, Qing; Zhang, Chenglong; Wang, JingWei

2017-11-01

For the objective of evaluating the contamination degree of heavy metals and analysing its variation trend in soil at a waste electrical and electronic equipment processing area in Shanghai, China, evaluation methods, which include single factor index method, geo-accumulation index method, comprehensive pollution index method, and potential ecological risk index method, were adopted in this study. The results revealed that the soil at a waste electrical and electronic equipment processing area was polluted by arsenic, cadmium, copper, lead, zinc, and chromium. It also demonstrated that the concentrations of heavy metals were increased over time. Exceptionally, the average value of the metalloid (arsenic) was 73.31 mg kg -1 in 2014, while it was 58.31 mg kg -1 in the first half of 2015, and it was 2.93 times and 2.33 times higher than that of the Chinese Environmental Quality Standard for Soil in 2014 and the first half of 2015, respectively. The sequences of the contamination degree of heavy metals in 2014 and the first half of 2015 were cadmium > lead > copper > chromium > zinc and cadmium > lead > chromium > zinc > copper. From the analysis of the potential ecological risk index method, arsenic and cadmium had higher ecological risk than other heavy metals. The integrated ecological risk index of heavy metals (cadmium, copper, lead, zinc, and chromium) and metalloid (arsenic) was 394.10 in 2014, while it was 656.16 in the first half of 2015, thus documenting a strong ecological risk.

Anemia and Micronutrient Status of Women of Childbearing Age and Children 6–59 Months in the Democratic Republic of the Congo

PubMed Central

Harvey-Leeson, Sarah; Karakochuk, Crystal D.; Hawes, Meaghan; Tugirimana, Pierrot L.; Bahizire, Esto; Akilimali, Pierre Z.; Michaux, Kristina D.; Lynd, Larry D.; Whitfield, Kyly C.; Moursi, Mourad; Boy, Erick; Foley, Jennifer; McLean, Judy; Houghton, Lisa A.; Gibson, Rosalind S.; Green, Tim J.

2016-01-01

Little is known about the micronutrient status of women and children in the Democratic Republic of the Congo, which is critical for the design of effective nutrition interventions. We recruited 744 mother-child pairs from South Kivu (SK) and Kongo Central (KC). We determined hemoglobin (Hb), serum zinc, vitamin B12, folate, ferritin, soluble transferrin receptor (sTfR), retinol binding protein (RBP), C-reactive protein, and α-1 acid glycoprotein concentrations. Anemia prevalence was determined using Hb adjusted for altitude alone and Hb adjusted for both altitude and ethnicity. Anemia prevalence was lower after Hb adjustment for altitude and ethnicity, compared to only altitude, among women (6% vs. 17% in SK; 10% vs. 32% in KC), children 6–23 months (26% vs. 59% in SK; 25% vs. 42% in KC), and children 24–59 months (14% vs. 35% in SK; 23% vs. 44% in KC), respectively. Iron deficiency was seemingly higher with sTfR as compared to inflammation-adjusted ferritin among women (18% vs. 4% in SK; 21% vs. 5% in KC), children 6–23 months (51% vs. 14% in SK; 74% vs. 10% in KC), and children 24–59 months (23% vs. 4% in SK; 58% vs. 1% in KC). Regardless of indicator, iron deficiency anemia (IDA) never exceeded 3% in women. In children, IDA reached almost 20% when sTfR was used but was only 10% with ferritin. Folate, B12, and vitamin A (RBP) deficiencies were all very low (<5%); RBP was 10% in children. The prevalence of anemia was unexpectedly low. Inflammation-adjusted zinc deficiency was high among women (52% in SK; 58% in KC), children 6–23 months (23% in SK; 20% in KC), and children 24–59 months (25% in SK; 27% in KC). The rate of biochemical zinc deficiency among Congolese women and children requires attention. PMID:26901219

Anemia and Micronutrient Status of Women of Childbearing Age and Children 6-59 Months in the Democratic Republic of the Congo.

PubMed

Harvey-Leeson, Sarah; Karakochuk, Crystal D; Hawes, Meaghan; Tugirimana, Pierrot L; Bahizire, Esto; Akilimali, Pierre Z; Michaux, Kristina D; Lynd, Larry D; Whitfield, Kyly C; Moursi, Mourad; Boy, Erick; Foley, Jennifer; McLean, Judy; Houghton, Lisa A; Gibson, Rosalind S; Green, Tim J

2016-02-17

Little is known about the micronutrient status of women and children in the Democratic Republic of the Congo, which is critical for the design of effective nutrition interventions. We recruited 744 mother-child pairs from South Kivu (SK) and Kongo Central (KC). We determined hemoglobin (Hb), serum zinc, vitamin B12, folate, ferritin, soluble transferrin receptor (sTfR), retinol binding protein (RBP), C-reactive protein, and α-1 acid glycoprotein concentrations. Anemia prevalence was determined using Hb adjusted for altitude alone and Hb adjusted for both altitude and ethnicity. Anemia prevalence was lower after Hb adjustment for altitude and ethnicity, compared to only altitude, among women (6% vs. 17% in SK; 10% vs. 32% in KC), children 6-23 months (26% vs. 59% in SK; 25% vs. 42% in KC), and children 24-59 months (14% vs. 35% in SK; 23% vs. 44% in KC), respectively. Iron deficiency was seemingly higher with sTfR as compared to inflammation-adjusted ferritin among women (18% vs. 4% in SK; 21% vs. 5% in KC), children 6-23 months (51% vs. 14% in SK; 74% vs. 10% in KC), and children 24-59 months (23% vs. 4% in SK; 58% vs. 1% in KC). Regardless of indicator, iron deficiency anemia (IDA) never exceeded 3% in women. In children, IDA reached almost 20% when sTfR was used but was only 10% with ferritin. Folate, B12, and vitamin A (RBP) deficiencies were all very low (<5%); RBP was 10% in children. The prevalence of anemia was unexpectedly low. Inflammation-adjusted zinc deficiency was high among women (52% in SK; 58% in KC), children 6-23 months (23% in SK; 20% in KC), and children 24-59 months (25% in SK; 27% in KC). The rate of biochemical zinc deficiency among Congolese women and children requires attention.

Zinc for the common cold.

PubMed

Singh, Meenu; Das, Rashmi R

2013-06-18

The common cold is one of the most widespread illnesses and is a leading cause of visits to the doctor and absenteeism from school and work. Trials conducted in high-income countries since 1984 investigating the role of zinc for the common cold symptoms have had mixed results. Inadequate treatment masking and reduced bioavailability of zinc from some formulations have been cited as influencing results. To assess whether zinc (irrespective of the zinc salt or formulation used) is efficacious in reducing the incidence, severity and duration of common cold symptoms. In addition, we aimed to identify potential sources of heterogeneity in results obtained and to assess their clinical significance. In this updated review, we searched CENTRAL (2012, Issue 12), MEDLINE (1966 to January week 2, 2013), EMBASE (1974 to January 2013), CINAHL (1981 to January 2013), Web of Science (1985 to January 2013), LILACS (1982 to January 2013), WHO ICTRP and clinicaltrials.gov. Randomised, double-blind, placebo-controlled trials using zinc for at least five consecutive days to treat, or for at least five months to prevent the common cold. Two review authors independently extracted data and assessed trial quality. Five trials were identified in the updated searches in January 2013 and two of them did not meet our inclusion criteria. We included 16 therapeutic trials (1387 participants) and two preventive trials (394 participants). Intake of zinc was associated with a significant reduction in the duration (days) (mean difference (MD) -1.03, 95% confidence interval (CI) -1.72 to -0.34) (P = 0.003) (I(2) statistic = 89%) but not the severity of common cold symptoms (MD -1.06, 95% CI -2.36 to 0.23) (P = 0.11) (I(2) statistic = 84%). The proportion of participants who were symptomatic after seven days of treatment was significantly smaller (odds ratio (OR) 0.45, 95% CI 0.20 to 1.00) (P = 0.05) than those in the control, (I(2 )statistic = 75%). The incidence rate ratio (IRR) of developing a cold (IRR 0.64, 95% CI 0.47 to 0.88) (P = 0.006) (I(2) statistic = 88%), school absence (P = 0.0003) and prescription of antibiotics (P < 0.00001) was lower in the zinc group. Overall adverse events (OR 1.58, 95% CI 1.19 to 2.09) (P = 0.002), bad taste (OR 2.31, 95% CI 1.71 to 3.11) (P < 0.00001) and nausea (OR 2.15, 95% CI 1.44 to 3.23) (P = 0.002) were higher in the zinc group. The very high heterogeneity means that the averaged estimates must be viewed with caution. Zinc administered within 24 hours of onset of symptoms reduces the duration of common cold symptoms in healthy people but some caution is needed due to the heterogeneity of the data. As the zinc lozenges formulation has been widely studied and there is a significant reduction in the duration of cold at a dose of ≥ 75 mg/day, for those considering using zinc it would be best to use it at this dose throughout the cold. Regarding prophylactic zinc supplementation, currently no firm recommendation can be made because of insufficient data. When using zinc lozenges (not as syrup or tablets) the likely benefit has to be balanced against side effects, notably a bad taste and nausea.

Effect of Process Parameters on the Structure and Properties of Galvanized Sheets

NASA Astrophysics Data System (ADS)

Shukla, S. K.; Saha, B. B.; Triathi, B. D.; Avtar, Ram

2010-07-01

The effect of galvanizing parameters on the structure (spangle size and coating microstructure) and properties (formability and corrosion resistance) of galvanized sheets was studied in a hot dip process simulator (HDPS) in a conventional Pb bearing (0.08-0.10%) zinc bath by varying zinc bath Al level (0.10-0.28%), bath temperature (718-743 K), dipping time (1.5-3.5 s), wiping gas flow rate (200-450 lpm), nozzle distance (15-17 mm) and wiping delay time (0.1-2.1 s). Al level in the range of 0.18-0.24% in combination with dipping time of 1.5-2.5 s and bath temperature of 718-733 K results in superior formability ( E cv: ~9.3 mm) of the composite (thickness: 0.8 mm). High post-dip cooling rates (~25 K/s) suppress spangle growth (spangle size: ~2 mm). The spangle size of the GI sheet strongly influences the corrosion rate which increases from 5.8 to 9.2 mpy with a decrease in spangle size from 17.5 to 3 mm. By controlling the Al level (0.20%) in zinc bath and bath temperature (733 K), the corrosion rate of mini-spangle GI sheet can be controlled to a level of 5.5 mpy.

[Effects of intercropping Sedum plumbizincicola and Apium graceolens on the soil chemical and microbiological properties under the contamination of zinc and cadmium from sewage sludge application].

PubMed

Nai, Feng-Jiao; Wu, Long-Hua; Liu, Hong-Yan; Ren, Jing; Liu, Wu-Xing; Luo, Yong-Ming

2013-05-01

Taking the vegetable soil with zinc- and cadmium contamination from a long-term sewage sludge application as the object, a pot experiment was conducted to study the remediation effect of Sedum plumbizincicola and Apium graceolens under continuous monoculture and intercropping. With the remediation time increased, both S. plumbizincicola and A. graceolens under monoculture grew poorly, but S. plumbizincicola under intercropping grew well. Under intercropping, the soil organic matter, total N, extractable N, and total P contents decreased significantly while the soil extractable K content had a significant increase, the counts of soil bacteria and fungi increased by 7.9 and 18.4 times and 3.7 and 4.3 times, respectively, but the soil urease and catalase activities remained unchanged, as compared with those under A. graceolens and S. plumbizincicola monoculture. The BIOLOG ECO micro-plates also showed that the carbon sources utilization level and the functional diversity index of soil microbial communities were higher under intercropping than under monoculture, and the concentrations of soil zinc and cadmium under intercropping decreased by 5.8% and 50.0%, respectively, with the decrements being significantly higher than those under monoculture. It was suggested that soil microbial effect could be one of the important factors affecting plant growth.

Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan.

PubMed

Aoki, Aya; Inoue, Maiko; Nguyen, Elizabeth; Obata, Ryo; Kadonosono, Kazuaki; Shinkai, Shoji; Hashimoto, Hideki; Sasaki, Satoshi; Yanagi, Yasuo

2016-02-05

This case-control study reports the association between nutrient intake and neovascular age-related macular degeneration (AMD) in Japan. The nutrient intake of 161 neovascular AMD cases from two university hospitals and 369 population-based control subjects from a cohort study was assessed using a brief-type self-administered questionnaire on diet history, which required respondent recall of the usual intake of 58 foods during the preceding month. Energy-adjusted nutrient intake values were compared between the groups. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs adjusted for smoking history, age, sex, chronic disease history, supplement use, and alcohol consumption. Logistic regression analysis demonstrated that low intakes of n-3 fatty acid, α-tocopherol, zinc, vitamin D, vitamin C, and β-carotene were associated with neovascular AMD (Trend P < 0.0001 for n-3 fatty acid, Trend P < 0.0001 for α-tocopherol, Trend P < 0.0001 for zinc, Trend P = 0.002 for vitamin D, Trend P = 0.04 for vitamin C, Trend P = 0.0004 for β-carotene). There was no association with retinol or cryptoxanthin intake and neovascular AMD (P = 0.67, 0.06).

Chromium and Ruthenium-Doped Zinc Oxide Thin Films for Propane Sensing Applications

PubMed Central

Gómez-Pozos, Heberto; González-Vidal, José Luis; Torres, Gonzalo Alberto; Rodríguez-Baez, Jorge; Maldonado, Arturo; de la Luz Olvera, María; Acosta, Dwight Roberto; Avendaño-Alejo, Maximino; Castañeda, Luis

2013-01-01

Chromium and ruthenium-doped zinc oxide (ZnO:Cr) and (ZnO:Ru) thin solid films were deposited on soda-lime glass substrates by the sol-gel dip-coating method. A 0.6 M solution of zinc acetate dihydrate dissolved in 2-methoxyethanol and monoethanolamine was used as basic solution. Chromium (III) acetylacetonate and Ruthenium (III) trichloride were used as doping sources. The Ru incorporation and its distribution profile into the films were proved by the SIMS technique. The morphology and structure of the films were studied by SEM microscopy and X-ray diffraction measurements, respectively. The SEM images show porous surfaces covered by small grains with different grain size, depending on the doping element, and the immersions number into the doping solutions. The sensing properties of ZnO:Cr and ZnO:Ru films in a propane (C3H8) atmosphere, as a function of the immersions number in the doping solution, have been studied in the present work. The highest sensitivity values were obtained for films doped from five immersions, 5.8 and 900, for ZnO:Cr and ZnO:Ru films, respectively. In order to evidence the catalytic effect of the chromium (Cr) and ruthenium (Ru), the sensing characteristics of undoped ZnO films are reported as well. PMID:23482091

Ligand exchange in quaternary alloyed nanocrystals--a spectroscopic study.

PubMed

Gabka, Grzegorz; Bujak, Piotr; Giedyk, Kamila; Kotwica, Kamil; Ostrowski, Andrzej; Malinowska, Karolina; Lisowski, Wojciech; Sobczak, Janusz W; Pron, Adam

2014-11-14

Exchange of initial, predominantly stearate ligands for pyridine in the first step and butylamine (BA) or 11-mercaptoundecanoic acid (MUA) in the second one was studied for alloyed quaternary Cu-In-Zn-S nanocrystals. The NMR results enabled us to demonstrate, for the first time, direct binding of the pyridine labile ligand to the nanocrystal surface as evidenced by paramagnetic shifts of the three signals attributed to its protons to 7.58, 7.95 and 8.75 ppm. XPS investigations indicated, in turn, a significant change in the composition of the nanocrystal surface upon the exchange of initial ligands for pyridine, which being enriched in indium in the 'as prepared' form became enriched in zinc after pyridine binding. This finding indicated that the first step of ligand exchange had to involve the removal of the surface layer enriched in indium with simultaneous exposure of a new, zinc-enriched layer. In the second ligand exchange step (replacement of pyridine with BA or MUA) the changes in the nanocrystal surface compositions were much less significant. The presence of zinc in the nanocrystal surface layer turned out necessary for effective binding of pyridine as shown by a comparative study of ligand exchange in Cu-In-Zn-S, Ag-In-Zn-S and CuInS2, carried out by complementary XPS and NMR investigations.

Lithiation-induced zinc clustering of Zn 3, Zn 12, and Zn 18 units in Zintl-like Ca ~30Li 3+xZn 60-x (x=0.44-1.38)

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

Lin, Qisheng

2014-11-14

Zinc clusters are not common for binary intermetallics with relatively low zinc content, but this work shows that zinc clustering can be triggered by lithiation, as exemplified by Ca ~30Li 3+xZn 60-x, P6/mmm, Z = 1, which can be directly converted from CaZn 2. Two end members of the solid solution (x = 0.44 and 1.38) were established and structurally characterized by single-crystal X-ray diffraction analyses: Ca 30Li 3.44(6)Zn59.56(6), a = 15.4651(9) Å, c = 9.3898(3) Å; Ca 30.45(2)Li 4.38(6)Zn 58.62(6), a = 15.524(3) Å, c = 9.413(2) Å. The structures of Ca ~30Li 3+xZn 60-x feature a condensed anionicmore » network of Zn3 triangles, lithium-centered Zn12 icosahedra, and arachno-(Zn,Li)18 tubular clusters that are surrounded respectively by Ca 14, Ca 20, and Ca 30 polyhedra. These polyhedra share faces and form a clathrate-like cationic framework. The specific occupation of lithium in the structure is consistent with theoretical “coloring” analyses. Analysis by the linear muffin-tin orbital (LMTO) method within the atomic sphere approximation reveals that Ca ~30Li 3+xZn 60-x is a metallic, Zintl-like phase with an open-shell electronic structure. The contribution of Ca–Zn polar covalent interactions is about 41%.« less

Determination of instream metal loads using tracer-injection and synoptic-sampling techniques in Wightman Fork, southwestern Colorado, September 1997

USGS Publications Warehouse

Ortiz, Roderick F.; Bencala, Kenneth E.

2001-01-01

Spatial determinations of the metal loads in Wightman Fork can be used to identify potential source areas to the stream. In September 1997, a chloride tracer-injection study was done concurrently with synoptic water-quality sampling in Wightman Fork near the Summitville Mine site. Discharge was determined and metal concentrations at 38 sites were used to generate mass-load profiles for dissolved aluminum, copper, iron, manganese, and zinc. The U.S. Environmental Protection Agency had previously identified these metals as contaminants of concern.Metal loads increased substantially in Wightman Fork near the Summitville Mine. A large increase occurred along a 60-meter reach that is north of the North Waste Dump and generally corresponds to a region of radial faults. Metal loading from this reach was equivalent to 50 percent or more of the dissolved aluminum, copper, iron, manganese, and zinc load upstream from the outfall of the Summitville Water Treatment Facility (SWTF). Overall, sources along the entire reach upstream from the SWTF were equivalent to 15 percent of the iron, 33 percent of the copper and manganese, 58 percent of the zinc, and 66 percent of the aluminum load leaving the mine site. The largest increases in metal loading to Wightman Fork occurred as a result of inflow from Cropsy Creek. Aluminum, iron, manganese, and zinc loads from Cropsy Creek were equivalent to about 40 percent of the specific metal load leaving the mine site. Copper, iron, and manganese loads from Cropsy Creek were nearly as large or larger than the load from sources upstream from the SWTF.

Effects of copper and tributyltin on stress protein abundance in the rotifer Brachionus plicatilis.

PubMed

Cochrane, B J; Irby, R B; Snell, T W

1991-01-01

1. Exposure of the rotifer Brachionus plicatilis to elevated temperature resulted in the synthesis of a number of proteins, including a prominent one of 58,000 Da (SP58). 2. This protein is immunologically crossreactive with the 65,000 Da heat shock protein of the moth Heliothis virescens, which is a member of a highly conserved family of mitochondrial proteins. 3. Exposure of rotifers to sublethal doses of CuSO4 leads to a 4-5-fold increase in abundance of SP58, with maximum increase occurring at a dose that is approximately 5% of the LC50 for that compound. 4. A similar response was seen with tributyl tin (TBT). Kinetics of induction were sigmoidal, with induction occurring in the range of 20-30 micrograms/l. 5. No response was observed when rotifers were exposed to aluminum chloride, mercury chloride, pentachlorophenol, sodium arsenite, sodium azide, sodium dodecyl sulfate, or zinc chloride. 6. These results indicate that changes in stress protein abundance may prove useful as a biomarker of exposure to particular toxicants.

Promotion of zinc tablets with ORS through child health weeks improves caregiver knowledge, attitudes, and practice on treatment of diarrhoea in Nigeria.

PubMed

Kung'u, Jacqueline K; Owolabi, Olumuyiwa; Essien, Grace; Aminu, Francis T; Ngnie-Teta, Ismael; Neufeld, Lynnette M

2015-03-01

We examined whether the Maternal, Newborn and Child Health Weeks (MNCHW) in Nigeria would present an opportunity to raise awareness of and demand for the use of zinc and ORS in the treatment for diarrhoea, guided by a conceptual framework designed to assess three theoretical underpinnings (characteristics and performance standard of the health workers, potential reach, and intensity of the intervention), along the impact pathway. Zinc and ORS with education for their appropriate use during the next diarrhoeal episode were delivered as part of the November 2010 and May 2011 MNCHW. On the day of but before participating in MNCHW activities, semi-structured interviews were used for collecting information on knowledge, attitudes, and practice (KAP) relating to diarrhoea from 602 caregivers with children aged less than five years. Forty-eight health workers were also interviewed. Nearly all health workers (98%) correctly mentioned the dosage of zinc while only 58% correctly stated the preparation of ORS. The proportion of caregivers with knowledge on the treatment for diarrhoea increased from 46.4% in November 2010 pre-MNCHW to 71.3% in May 2011 pre-MNCHW interviews (p<0.001). More caregivers correctly mentioned the dosage of zinc (80.9%) and stated the preparation of ORS (88.8%) in the November 2010 exit interview immediately after the MNCHW encounter compared to the levels a few months later in the home follow-up visit (53.1% and 37.4% respectively). After attending both rounds of November 2010 and May 2011 MNCHW, caregivers' knowledge on the treatment of diarrhoea increased seven times compared to the caregivers who attended the May 2011 MNCHW only (OR=7.0, p<0.001). Additionally, caregivers were 40% less likely to seek advice outside the home in the treatment for diarrhoea if they had attended both the MNCHWs than if they had attended the May 2011 MNCHW only (OR=0.6, p<0.029). We conclude that providing opportunities for caregivers to receive a sample of zinc and ORS and to learn about its use in the treatment for diarrhoea, from trained health workers during MNCHW, has the potential to increase KAP relating to the use of zinc and ORS in the treatment for diarrhoea and for future diarrhoeal episodes.

Relative toxicity of lead and selected substitute shot types to game farm mallards

USGS Publications Warehouse

Irby, H.D.; Locke, L.N.; Bagley, George E.

1967-01-01

The acute toxicity of lead, three types of plastic-coated lead, two lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot were tested in year-old male game farm mallards. Mallards (Anus platyrhynchos) were fed eight number 6 shot of each type and observed for a period of 60 days. Ducks used totaled 230 and most shot types were tested in three replicates of 8 ducks each. Mortality and losses of body weight were the criteria used for judging toxicity. Three types of plastic-coated lead shot were as toxic (93 percent) as the commercial lead shot (96 percent). The average mortality in mallards fed lead-magnesium alloy shot was less (58 percent) than that occurring in birds fed commercial lead shot. Mortality among mallards fed iron, copper, zinc-coated iron or molybdenum-coated iron shot was significantly less than in birds fed lead shot, and was not significantly greater than the conrtols.

The Effect of Tear Supplementation with 0.15% Preservative-Free Zinc-Hyaluronate on Ocular Surface Sensations in Patients with Dry Eye.

PubMed

Perényi, Kristóf; Dienes, Lóránt; Kornafeld, Anna; Kovács, Balázs; Kiss, Huba J; Szepessy, Zsuzsanna; Nagy, Zoltán Z; Barsi, Árpád; Acosta, M Carmen; Gallar, Juana; Kovács, Illés

To evaluate the effect of tear supplementation with preservative free 0.15% zinc-hyaluronate on ocular surface sensations and corneal sensitivity in dry eye patients. Ocular surface sensations were assessed using the ocular surface disease index (OSDI) questionnaire and by recording ocular sensations during forced blinking in parallel with noninvasive tear film breakup time measurement in 20 eyes of 20 dry eye patients. Corneal sensitivity thresholds to selective stimulation of corneal mechano-, thermal- and chemical receptors were measured using the Belmonte gas esthesiometer. All baseline measurements were repeated after 1 month of treatment with 0.15% zinc-hyaluronate. After 1 month, a significant decrease in mean OSDI score (from 35.66 ± 12.36 to 15.03 ± 11.22; P < 0.001) and a significant improvement in tear film breakup time (from 3.83 ± 0.80 to 8.67 ± 4.50 s; P < 0.001) was observed compared to baseline. Sensory responses during the interblink period also significantly decreased after 1 month (P < 0.004). Corneal sensitivity thresholds to mechanical stimulation (90.61 ± 20.35 vs. 103.92 ± 17.97 mL/min; P < 0.025) and chemical stimulation (33.21 ± 0.51 vs. 33.58% ± 0.44% CO 2 ; P < 0.025) significantly increased after 1 month, however sensitivity thresholds to thermal stimulation remained unchanged compared to baseline (P > 0.05). Prolonged use of 0.15% zinc-hyaluronate results in an improvement of tear film stability and a decrease of dry eye complaints. The decrease in corneal mechano-and polymodal receptor excitability suggests that zinc-hyaluronate helps to recover normal corneal sensitivity, and thus might have a beneficial additional effect on reducing ocular surface complaints in dry eye patients.

Effect of lanthanum substitution on structural and magnetic properties of nickel zinc ferrites

NASA Astrophysics Data System (ADS)

Šoka, Martin; Ušáková, Mariana; Dosoudil, Rastislav; Ušák, Elemír; Lokaj, Ján

2018-04-01

The purpose of the presented research is to investigate the effect of La3+ ions substitution for Fe3+ ions in Ni0.42Zn0.58LaxFe2-xO4 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) ferrite compositions prepared by the innovated glycine-nitrate process based on auto-combustion method. Structural and magnetic properties of examined samples were estimated by the analysis of X-ray spectra, EDAX spectrum, SEM micrographs, thermomagnetic characteristics, magnetic hysteresis loops and complex permeability spectra.

Inverted organic photovoltaic device with a new electron transport layer

NASA Astrophysics Data System (ADS)

Kim, Hyeong Pil; Yusoff, Abd Rashid bin Mohd; Kim, Hyo Min; Lee, Hee Jae; Seo, Gi Jun; Jang, Jin

2014-03-01

We demonstrate that there is a new solution-processed electron transport layer, lithium-doped zinc oxide (LZO), with high-performance inverted organic photovoltaic device. The device exhibits a fill factor of 68.58%, an open circuit voltage of 0.86 V, a short-circuit current density of -9.35 cm/mA2 along with 5.49% power conversion efficiency. In addition, we studied the performance of blend ratio dependence on inverted organic photovoltaics. Our device also demonstrates a long stability shelf life over 4 weeks in air.

MicroRNAs Associated with Epithelial-Mesenchymal Transition Can Be Targeted to Inhibit Peritoneal Dissemination of Human Scirrhous Gastric Cancers.

PubMed

Takei, Yoshifumi; Shen, Guodong; Morita-Kondo, Ayami; Hara, Toshifumi; Mihara, Keichiro; Yanagihara, Kazuyoshi

2018-05-30

Scirrhous gastric cancers grow rapidly, and frequently invade the peritoneum. Such peritoneal dissemination properties markedly reduce patient survival. Thus, an effective means for inhibiting peritoneal dissemination is urgently required. We previously established a cell line, HSC-58, from a scirrhous gastric cancer patient, and further successfully isolated a metastatic line, 58As9, in nude mice upon orthotopic inoculation. Using the lines, we examined the mechanism underlying peritoneal dissemination from the viewpoint of microRNA (miRNA) expression. miRNA array and qRT-PCR analysis showed that the expressions of epithelial-mesenchymal transition (EMT)-associated miRNAs such as miR-200c and miR-141 were significantly low in 58As9. Using 58As9 with stably overexpressing miR-200c, miR-141, or both, together with a luciferase reporter assay, we found that miR-200c targeted zinc finger E-box-binding homeobox 1 (ZEB1) and miR-141 targeted ZEB2. The overexpressed lines reversed the EMT status from mesenchymal to epithelial in 58As9, and significantly reduced the invasion activity and peritoneal dissemination for a significant prolongation of survival in the orthotopic tumor models in nude mice. EMT-associated miRNAs such as miR-200c and miR-141 and their target genes ZEB1/ZEB2 have good potential for antiperitoneal dissemination therapy in patients with scirrhous gastric cancers. © 2018 S. Karger AG, Basel.

Prostate cancer outcome and tissue levels of metal ions

USGS Publications Warehouse

Sarafanov, A.G.; Todorov, T.I.; Centeno, J.A.; MacIas, V.; Gao, W.; Liang, W.-M.; Beam, C.; Gray, Marion A.; Kajdacsy-Balla, A.

2011-01-01

BACKGROUNDThere are several studies examining prostate cancer and exposure to cadmium, iron, selenium, and zinc. Less data are available on the possible influence of these metal ions on prostate cancer outcome. This study measured levels of these ions in prostatectomy samples in order to examine possible associations between metal concentrations and disease outcome.METHODSWe obtained formalin fixed paraffin embedded tissue blocks of prostatectomy samples of 40 patients with PSA recurrence, matched 1:1 (for year of surgery, race, age, Gleason grading, and pathology TNM classification) with tissue blocks from 40 patients without recurrence (n = 80). Case–control pairs were compared for the levels of metals in areas adjacent to tumors. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for quantification of Cd, Fe, Zn, and Se.RESULTSPatients with biochemical (PSA) recurrence of disease had 12% lower median iron (95 µg/g vs. 111 µg/g; P = 0.04) and 21% lower zinc (279 µg/g vs. 346 µg/g; P = 0.04) concentrations in the normal-appearing tissue immediately adjacent to cancer areas. Differences in cadmium (0.489 µg/g vs. 0.439 µg/g; 4% higher) and selenium (1.68 µg/g vs. 1.58 µg/g; 5% higher) levels were not statistically significant in recurrence cases, when compared to non-recurrences (P = 0.40 and 0.21, respectively).CONCLUSIONSThere is an association between low zinc and low iron prostate tissue levels and biochemical recurrence in prostate cancer. Whether these novel findings are a cause or effect of more aggressive tumors, or whether low zinc and iron prostatic levels raise implications for therapy, remains to be investigated. 

A macroinvertebrate assessment of Ozark streams located in lead-zinc mining areas of the Viburnum Trend in southeastern Missouri, USA

USGS Publications Warehouse

Poulton, Barry C.; Allert, Ann L.; Besser, John M.; Schmitt, Christopher J.; Brumbaugh, William G.; Fairchild, James F.

2010-01-01

The Viburnum Trend lead-zinc mining subdistrict is located in the southeast Missouri portion of the Ozark Plateau. In 2003 and 2004, we assessed the ecological effects of mining in several watersheds in the region. We included macroinvertebrate surveys, habitat assessments, and analysis of metals in sediment, pore water, and aquatic biota. Macroinvertebrates were sampled at 21 sites to determine aquatic life impairment status (full, partial, or nonsupport) and relative biotic condition scores. Macroinvertebrate biotic condition scores were significantly correlated with cadmium, nickel, lead, zinc, and specific conductance in 2003 (r = -0.61 to -0.68) and with cadmium, lead, and pore water toxic units in 2004 (r = -0.55 to -0.57). Reference sites were fully supporting of aquatic life and had the lowest metals concentrations and among the highest biotic condition scores in both years. Sites directly downstream from mining and related activities were partially supporting, with biotic condition scores 10% to 58% lower than reference sites. Sites located greater distances downstream from mining activities had intermediate scores and concentrations of metals. Results indicate that elevated concentrations of metals originating from mining activities were the underlying cause of aquatic life impairment in several of the streams studied. There was general concurrence among the adversely affected sites in how the various indicators responded to mining activities during the overall study.

Functional analysis of structurally related soybean GmWRKY58 and GmWRKY76 in plant growth and development.

PubMed

Yang, Yan; Chi, Yingjun; Wang, Ze; Zhou, Yuan; Fan, Baofang; Chen, Zhixiang

2016-08-01

WRKY transcription factors constitute a large protein superfamily with a predominant role in plant stress responses. In this study we report that two structurally related soybean WRKY proteins, GmWRKY58 and GmWRKY76, play a critical role in plant growth and flowering. GmWRKY58 and GmWRKY76 are both Group III WRKY proteins with a C2HC zinc finger domain and are close homologs of AtWRKY70 and AtWRKY54, two well-characterized Arabidopsis WRKY proteins with an important role in plant responses to biotic and abiotic stresses. GmWRKY58 and GmWRKY76 are both localized to the nucleus, recognize the TTGACC W-box sequence with a high specificity, and function as transcriptional activators in both yeast and plant cells. Expression of GmWRKY58 and GmWRKY76 was detected at low levels in roots, stem, leaves, flowers, and pods. Expression of the two genes in leaves increased substantially during the first 4 weeks after germination but steadily declined thereafter with increased age. To determine their biological functions, transgenic Arabidopsis plants were generated overexpressing GmWRKY58 or GmWRKY76 Unlike AtWRKY70 and AtWRKY54, overexpression of GmWRKY58 or GmWRKY76 had no effect on disease resistance and only small effects on abiotic stress tolerance of the transgenic plants. Significantly, transgenic Arabidopsis plants overexpressing GmWRKY58 or GmWRKY76 flowered substantially earlier than control plants and this early flowering phenotype was associated with increased expression of several flowering-promoting genes, some of which are enriched in W-box sequences in their promoters recognized by GmWRKY58 and GmWRKY76. In addition, virus-induced silencing of GmWRKY58 and GmWRKY76 in soybean resulted in stunted plants with reduced leaf expansion and terminated stem growth. These results provide strong evidence for functional divergence among close structural homologs of WRKY proteins from different plant species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Functional analysis of structurally related soybean GmWRKY58 and GmWRKY76 in plant growth and development

PubMed Central

Yang, Yan; Chi, Yingjun; Wang, Ze; Zhou, Yuan; Fan, Baofang; Chen, Zhixiang

2016-01-01

WRKY transcription factors constitute a large protein superfamily with a predominant role in plant stress responses. In this study we report that two structurally related soybean WRKY proteins, GmWRKY58 and GmWRKY76, play a critical role in plant growth and flowering. GmWRKY58 and GmWRKY76 are both Group III WRKY proteins with a C2HC zinc finger domain and are close homologs of AtWRKY70 and AtWRKY54, two well-characterized Arabidopsis WRKY proteins with an important role in plant responses to biotic and abiotic stresses. GmWRKY58 and GmWRKY76 are both localized to the nucleus, recognize the TTGACC W-box sequence with a high specificity, and function as transcriptional activators in both yeast and plant cells. Expression of GmWRKY58 and GmWRKY76 was detected at low levels in roots, stem, leaves, flowers, and pods. Expression of the two genes in leaves increased substantially during the first 4 weeks after germination but steadily declined thereafter with increased age. To determine their biological functions, transgenic Arabidopsis plants were generated overexpressing GmWRKY58 or GmWRKY76. Unlike AtWRKY70 and AtWRKY54, overexpression of GmWRKY58 or GmWRKY76 had no effect on disease resistance and only small effects on abiotic stress tolerance of the transgenic plants. Significantly, transgenic Arabidopsis plants overexpressing GmWRKY58 or GmWRKY76 flowered substantially earlier than control plants and this early flowering phenotype was associated with increased expression of several flowering-promoting genes, some of which are enriched in W-box sequences in their promoters recognized by GmWRKY58 and GmWRKY76. In addition, virus-induced silencing of GmWRKY58 and GmWRKY76 in soybean resulted in stunted plants with reduced leaf expansion and terminated stem growth. These results provide strong evidence for functional divergence among close structural homologs of WRKY proteins from different plant species. PMID:27335454

OsLOL1, a C2C2-type zinc finger protein, interacts with OsbZIP58 to promote seed germination through the modulation of gibberellin biosynthesis in Oryza sativa.

PubMed

Wu, Jiahe; Zhu, Chuanfeng; Pang, Jinhuan; Zhang, Xiangrong; Yang, Chunlin; Xia, Guixian; Tian, Yingchuan; He, Chaozu

2014-12-01

Seed germination is a key developmental process in the plant life cycle that is influenced by various environmental cues and phytohormones through gene expression and a series of metabolism pathways. In the present study, we investigated a C2C2-type finger protein, OsLOL1, which promotes gibberellin (GA) biosynthesis and affects seed germination in Oryza sativa (rice). We used OsLOL1 antisense and sense transgenic lines to explore OsLOL1 functions. Seed germination timing in antisense plants was restored to wild type when exogenous GA3 was applied. The reduced expression of the GA biosynthesis gene OsKO2 and the accumulation of ent-kaurene were observed during germination in antisense plants. Based on yeast two-hybrid and firefly luciferase complementation analyses, OsLOL1 interacted with the basic leucine zipper protein OsbZIP58. The results from electrophoretic mobility shift and dual-luciferase reporter assays showed that OsbZIP58 binds the G-box cis-element of the OsKO2 promoter and activates LUC reporter gene expression, and that interaction between OsLOL1 and OsbZIP58 activates OsKO2 gene expression. In addition, OsLOL1 decreased SOD1 gene expression and accelerated programmed cell death (PCD) in the aleurone layer of rice grains. These findings demonstrate that the interaction between OsLOL1 and OsbZIP58 influences GA biosynthesis through the activation of OsKO2 via OsbZIP58, thereby stimulating aleurone PCD and seed germination. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Zinc isotope anomalies. [in Allende meteorite

NASA Technical Reports Server (NTRS)

Volkening, J.; Papanastassiou, D. A.

1990-01-01

The Zn isotope composition in refractory-element-rich inclusions of the Allende meteorite are determined. Typical inclusions contain normal Zn. A unique inclusion of the Allende meteorite shows an excess for Zn-66 of 16.7 + or - 3.7 eu (1 eu = 0.01 percent) and a deficit for Zn-70 of 21 + or - 13 eu. These results indicate the preservation of exotic components even for volatile elements in this inclusion. The observed excess Zn-66 correlates with excesses for the neutron-rich isotopes of Ca-48, Ti-50, Cr-54, and Fe-58 in the same inclusion.

Correlation of Aflatoxin Contamination With Zinc Content of Chicken Feed †

PubMed Central

Jones, Frank T.; Hagler, Winston M.; Hamilton, Pat B.

1984-01-01

Feed samples from chicken houses in five commercial chicken operations were analyzed for Zn, Mn, Fe, Cu, Cd, and aflatoxin content. Mean aflatoxin content of these samples was 14 ppb (14 ng/g) as opposed to 1.2 ppb in samples taken when the feed was made. Aflatoxin content of the feed samples correlated (r = 0.325) significantly (P < 0.05) with Zn content but not with Mn, Fe, or Cu, all of which correlated significantly with Zn. Zn content of unamended feed (<20 ppm [20 μg/g]) is normally supplemented with a mineral premix containing Zn, Mn, Fe, and Cu to meet the nutrient requirements of chickens (40 ppm of Zn). The mean zinc concentration of the feed samples (117 ppm) was about threefold greater than the nutrient requirement and ranged from 58 to 162 ppm in individual samples. These field survey results parallel earlier reports of augmented production of aflatoxin in monocultures of aflatoxigenic fungi in corn and other ingredients supplemented with Zn. These results suggest that stricter control of Zn levels during manufacture could reduce aflatoxin contamination of feed consumed by chickens. PMID:16346486

Synthesis of zinc oxide porous structures by anodization with water as an electrolyte

NASA Astrophysics Data System (ADS)

Shetty, Amitha; Nanda, Karuna Kar

2012-10-01

We report a simple, reliable and one-step method of synthesizing ZnO porous structures at room temperature by anodization of zinc (Zn) sheet with water as an electrolyte and graphite as a counter electrode. We observed that the de-ionized (DI) water used in the experiment is slightly acidic (pH=5.8), which is due to the dissolution of carbon dioxide from the atmosphere forming carbonic acid. Porous ZnO is characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and photoluminescence (PL) studies. The current-transient measurement is carried out using a Gamry Instruments Reference 3000 and the thickness of the deposited films is measured using a Dektak surface profilometer. The PL, Raman and X-ray photoelectron spectroscopy are used to confirm the presence of ZnO phase. We have demonstrated that the hybrid structures of ZnO and poly (3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) exhibit good rectifying characteristics. The evaluated barrier height and the ideality factor are 0.45 eV and 3.6, respectively.

Correlation of aflatoxin contamination with zinc content of chicken feed

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

Jones, F.T.; Hagler, W.M. Jr.; Hamilton, P.B.

Feed samples from chicken houses in five commercial chicken operations were analyzed for Zn, Mn, Fe, Cu, Cd, and aflatoxin content. Mean aflatoxin content of these samples was 14 ppb (14 ng/g) as opposed to 1.2 ppb in samples taken when the feed was made. Aflatoxin content of the feed samples correlated significantly with Zn content but not with Mn, Fe, or Cu, all of which correlated significantly with Zn. Zn content of unamended feed (<20 ppm (20 ..mu..g/g) is normally supplemented with a mineral premix containing Zn, Mn, Fe, and Cu to meet the nutrient requirements of chickens (40more » ppm of Zn). The mean zinc concentration of the feed samples (117 ppm) was about threefold greater than the nutrient requirement and ranged from 58 to 162 ppm in individual samples. These field survey results parallel earlier reports of augmented production of aflatoxin in monocultures of aflatoxigenic fungi in corn and other ingredients supplemented with Zn. These results suggest that stricter control of Zn levels during manufacture could reduce aflatoxing contamination of feed consumed by chickens.« less

Comparison of dexpanthenol and zinc oxide ointment with ointment base in the treatment of irritant diaper dermatitis from diarrhea: a multicenter study.

PubMed

Wananukul, Siriwan; Limpongsanuruk, Wanida; Singalavanija, Srisupalak; Wisuthsarewong, Wanee

2006-10-01

Severity of irritant diaper dermatitis (IDD) from diarrhea varies from patient to patient depending on the nature of feces and the number of bowel movements. The purpose of the present study was to compare the effectiveness of dexpanthenol and zinc oxide ointment with ointment base in the treatment of irritant diaper dermatitis from acute diarrhea in children by measuring transepidermal water loss (TEWL). Forty-six children with diarrhea were prospectively, block randomized, investigator-blinded to receive dexpanthenol and zinc oxide ointment on one side and ointment base on the other side. TEWL was measured before and on days 1, 3, and 7 of treatment together with the assessment of severity score. The efficacy of treatment was defined by complete clearance of the lesion. TEWL in the treated and control side was not different before the application of the topical medication. In the present study, the efficacy of 5% dexpanthenol and zinc oxide ointment on D3 was 39% (18from 46 patients) compared to 32% in the ointment base side. On D7, the efficacy of the treated side was 58.7% and the ointment base side was 56%. The patients who still had skin lesions were those who had prolonged diarrhea. On the treated side, the mean of TEWL was lower than the control side on DI (p = 0.18) and had significant improvement on D3 (p = 0. 002). At the end of the present study, TEWL on the treated side was less than TEWL of the control side but it did not have statistical significance (p = 0.07). There was no rash or sign of abnormality on the treated side at the end of D7. In the treatment of lDD from acute diarrhea, 5% dexpanthenol and zinc oxide ointment significantly decreased TEWL in the treated side more than the ointment base on day 3 but the severity score was not significantly different on days 1, 3 and 7.

The bulk composition and leaching properties of electroplating sludge prior/following the solidification/stabilization by calcium oxide.

PubMed

Orescanin, Visnja; Mikulic, Nenad; Mikelic, Ivanka Lovrencic; Posedi, Mario; Kampic, Stefica; Medunic, Gordana

2009-10-01

Eighteen samples of electroplating sludge were taken from three vertical profiles of waste storage pond of the zinc plating facility. Dry matter and organic matter content, pH value, bulk concentrations and leachate composition were determined. A sludge sample with the highest zinc value in the leachate was treated with calcium oxide (10% to 70%) and the obtained solidificate was repeatedly tested. There were found significant variations of all measured parameters among the profiles of untreated waste. Dry matter content varied from 125 to 455 mgg(-1), organic matter varied from 94.3 to 293.9 mgg(-1), and pH value varied from 3.42 to 5.90 (mean 4.34). Iron content ranged from 38.4 to 191.4 mgg(-1) (mean 136 mgg(-1); RSD 0.25), while zinc ranged from 10.9 to 58.2 mgg(-1) (mean 33.4 mgg(-1); RSD 0.38). According to its DIN38414-S4 leachate composition, this material was not suitable for landfilling of inert waste since zinc and nickel mean values were 10 and 1.5 times higher, respectively, and maximum values 27 and 2.5 times higher, respectively, compared to the upper permissible limit. Maximum values of Cr(VI), Fe, Ni, Cu, and Zn in the DIN38414-S4 leachate were 0.183 mgL(-1), 34.085 mgL(-1), 1.052 mgL(-1), 0.829 mgL(-1) and 107.475 mgL(-1)L, respectively. Following the solidification/stabilization procedure with CaO (sample/CaO = 90/10), concentrations of Cr(VI), Fe, Cu and Zn were reduced 92, 44, 66 and 57 times, respectively, compared to the untreated sample. The addition of 50% of CaO into the sludge reduced zinc and nickel concentrations 79 and 45 times, respectively, in the DIN38414-S4 leachate of the solidified waste compared to the original sludge, thereby converting an hazardous waste into the inert material suitable for landfilling or reuse in the construction processes.

[The content of zinc and cadmium in medicinal plants and their infusions].

PubMed

Celechovská, O; Pízová, M; Konícková, J

2004-11-01

The content of cadmium and zinc in the elder (Sambucus nigra) and the lime tree (Tilia spec.) collected from four different localities in the Czech Republic was studied. From the elder, the flowers (Sambuci flos), pollen, and fruits (Sambuci fructus) were collected, from the lime tree, the flowers (Tiliae flos) were used. The highest content of Zn and Cd was found in the pollen of the elder ( Zn 65.0-94.4 mg.kg(-1), Cd 14.1-43.1 microg.kg(-1)), the lowest in its fruits (Zn 4.5-14.7 mg.kg(-1), Cd max. 8.1 microg.kg(-1)). The content of Zn was lower in the Tiliae flos (13.8-32.5 mg.kg(-1)) than in the Sambuci flos (30.8-49.9 mg.kg(-1)). The Cd content in Tiliae flos (9.9-58.9 microg.kg(-1)) was higher in comparison with the Sambuci flos (3.3-15.3 microg.kg(-1)). The concentration of Cd in the infusion (10, 30 and 60 min) was found under the detection limit of the used metod (0.04 microg.l(-1)). The highest content of Zn transported to the infusion came from the Tiliae flos (20-36%), from the Sambuci flos (17-25%), and from the Sambuci fruits (12-19%). The content of both zinc and cadmium in the studied drugs depends on the localities of the original of plants.

Micronutrient Deficiencies and Related Factors in School-Aged Children in Ethiopia: A Cross-Sectional Study in Libo Kemkem and Fogera Districts, Amhara Regional State

PubMed Central

Herrador, Zaida; Sordo, Luis; Gadisa, Endalamaw; Buño, Antonio; Gómez-Rioja, Rubén; Iturzaeta, Jose Manuel; de Armas, Lisset Fernandez; Benito, Agustín; Aseffa, Abraham; Moreno, Javier; Cañavate, Carmen; Custodio, Estefania

2014-01-01

Introduction The present study describes the distribution of selected micronutrients and anaemia among school-aged children living in Libo Kemkem and Fogera (Amhara State, Ethiopia), assessing differences by socio-demographic characteristics, health status and dietary habits. Methods A cross-sectional survey was carried out during May–December 2009. Socio-demographic characteristics, health status and dietary habits were collected. Biomarkers were determined for 764 children. Bivariate and multivariable statistical methods were employed to assess micronutrient deficiencies (MD), anaemia, and their association with different factors. Results More than two thirds of the school-aged children (79.5%) had at least one MD and 40.5% had two or more coexisting micronutrient deficiencies. The most prevalent deficiencies were of zinc (12.5%), folate (13.9%), vit A (29.3%) and vit D (49%). Anaemia occurred in 30.9% of the children. Children living in rural areas were more likely to have vit D insufficiency [OR: 5.9 (3.7–9.5)] but less likely to have folate deficiency [OR: 0.2 (0.1–0.4)] and anaemia [OR: 0.58 (0.35–0.97)]. Splenomegaly was positively associated with folate deficiency and anaemia [OR: 2.77 (1.19–6.48) and 4.91 (2.47–9.75)]. Meat and fish consumption were inversely correlated with zinc and ferritin deficiencies [OR: 0.2 (0.1–0.8) and 0.2 (0.1–0.9)], while oil consumption showed a negative association with anaemia and deficiencies of folate and vitamin A [0.58 (0.3–0.9), OR: 0.5 (0.3–0.9) and 0.6 (0.4–0.9)]. Serum ferritin levels were inversely correlated to the presence of anaemia (p<0.005). Conclusion There is a high prevalence of vitamin A deficiency and vitamin D insufficiency and a moderate prevalence of zinc and folate deficiencies in school-aged children in this area. The inverse association of anaemia and serum ferritin levels may be due to the presence of infectious diseases in the area. To effectively tackle malnutrition, strategies should target not only isolated micronutrient supplementation but also diet diversification. PMID:25546056

Nutrition Concerns of Insufficient and Excessive Intake of Dietary Minerals in Lactating Women: A Cross-Sectional Survey in Three Cities of China.

PubMed

Zhao, Ai; Xue, Yong; Zhang, Yumei; Li, Wenjun; Yu, Kai; Wang, Peiyu

2016-01-01

Objectives of this study were 1) to investigate the mineral intake by Chinese lactating women, 2) to explore the dietary source of minerals, and 3) the ratios between different dietary minerals. A total of 468 lactating women in 5-240 days post-partum participated in this study. Food intakes by participants were measured using one time of 24-hour dietary recall, and minerals from food were calculated based on the Chinese Food Composition Table, second edition. In post-partum, women had inadequate food intake. 81.0% of women's daily intake of dairy products was lower than 300g, and 97.1% of women's daily intake of salt over 6g. For mineral intake, there were 81.8%, 59.0%, 47.6%, 45.7% and 66.8% of women's calcium, magnesium, iron, zinc and selenium intake lower than the estimated average requirement, respectively, and 91.7% of women's excessive intake of sodium. The calcium/phosphorus and sodium/potassium ratios were 0.41±0.26/1 and 3.13±2.89/1, respectively. Considering the dietary sources of minerals, 27.3%, 25.3% and 30.1% of iron, zinc and calcium were from animal-based food, respectively, and 60.3%, 66.1% and 58.0% of iron, zinc and calcium were from plant-based food, respectively. The phosphorus-protein ratio was 0.014±0.003/1. Lactation stage was associated with nutrient intake. Women within 30 days post-partum and the ones who live in Guangzhou had a significantly lower intake of certain minerals, while women with a high education experience had a high intake of calcium, potassium, iron and zinc. Productive age, whether obese or not, and delivery ways were not associated with mineral intakes (P all >0.05). Chinese women in three studied cities had an inappropriate food intake and resulted in both insufficient and excessive intakes of certain minerals.

Effects of chronic dietary exposure of zinc oxide nanoparticles on the serum protein profile of juvenile common carp (Cyprinus carpio L.).

PubMed

Chupani, Latifeh; Zusková, Eliška; Niksirat, Hamid; Panáček, Aleš; Lünsmann, Vanessa; Haange, Sven-Bastiaan; von Bergen, Martin; Jehmlich, Nico

2017-02-01

Zinc oxide (ZnO) nanoparticles (NPs) have been dramatically used in industry, biology, and medicine. Despite their interesting physico-chemical properties for application in various industrial, medical, and consumer products, safe use of ZnO NPs are under challenges due to the inadequate information related to their toxicological endpoints. Proteomics was applied to evaluate the sub-lethal effects of dietary exposure to ZnO NPs on serum proteome profile of juvenile common carp, (Cyprinus carpio). Therefore, ZnO NPs solution (500mgkg -1 of feed) was added to a commercial carp feed for six weeks. We compared the serum proteome profile from 7 controls and 7 treated fish. In addition, zinc accumulation were measured in intestine, liver, gill and brain. In total, we were able to identify 326 proteins from 6845 distinct peptides. As a result of the data analysis, the abundance levels of four proteins were significantly altered (fold change (fc) ≥2 and p<0.05) after dietary exposure to ZnO NPs. The protein levels of the complement component C4-2 (fc 2.5) and the uncharacterised protein encoded by kng1 (fc 5.8) were increased and major histocompatibility class I (fc 4.9) and the uncharacterised protein encoded by lum (fc 3.5) were decreased (fc 2.5). Molecular pathway analysis revealed four canonical pathways including acute-phase response signalling, liver and retinoid X receptors activation, and intrinsic and extrinsic prothrombin activation pathways as significantly regulated in the treated fish. No significant difference was observed for zinc accumulation in exposed fish compared to controls. In summary, despite no apparent accumulation, ZnO NPs exposure to common carp probably disturbs the fish homeostasis by affecting proteins of the haematological and the immune systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Zinc and copper distribution in swine wastewater treated by anaerobic digestion.

PubMed

Cestonaro do Amaral, André; Kunz, Airton; Radis Steinmetz, Ricardo Luís; Justi, Karin Cristiane

2014-08-01

Swine wastewater contain high levels of metals, such as copper and zinc, which can cause a negative impact on the environment. Anaerobic digestion is a process commonly used to remove carbon, and can act on metal availability (e.g., solubility or oxidation state). The present study aimed to evaluate the influence of anaerobic digestion on total Zn and Cu contents, and their chemical fractioning due to the biodegradation of the effluent over different hydraulic retention times (HRTs). The sequential extraction protocol proposed by the Community Bureau of Reference (BCR), plus two additional fractions, was the method chosen for this study of Cu and Zn distribution evaluation in swine wastewater. The Zn and Cu concentrations in raw swine manure were 63.58 ± 27.72 mg L(-1) and 8.98 ± 3.99 mg L(-1), respectively. The metal retention capacity of the bioreactor decreased when the HRT was reduced from 17.86 d to 5.32 d. Anaerobic digestion had a direct influence on zinc and copper distribution when raw manure (RM) and digested manure (DM) were compared. The reducible fraction showed a reduction of between 3.17% and 7.84% for Zn and between 2.52% and 11.92% for Cu when DM was compared with RM. However, the metal concentration increased in the oxidizable fraction of DM, viz. from 3.01% to 10.64% for Zn and from 4.49% to 16.71% for Cu, thus demonstrating the effect of anaerobic conditions on metal availability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trace metal uptake by garden herbs and vegetables.

PubMed

Shariatpanahi, M; Anderson, A C; Mather, F

1986-12-01

In many regions of Iran, crops are irrigated with municipal and industrial wastewater that contain a variety of metals. The purpose of this study was to simulate the level of metals that may be presented to plants over a growing season in a controlled laboratory setting. Cadmium, lead, arsenic, chromium, mercury, nickel, copper, zinc, and selenium were applied to plants at the high rate of 200 g metal/ha/wk. The following plants were examined for metal accumulation and effects on yield: garden cress (Lipidium sativum), leek (Allium porrum L.), basil (Ocimum basilicum L.), mint (Mentha arvensis L.), onion (Allium capa L.), radish (Raphanus sativus L.), and tarragon (Artemisia draculus L.). All plants showed significant uptake of all metals when compared to control (p=0.05), and growth was significantly reduced (p=0.05). Cadmium and chromium levels of 85±7.4 and 47.6±8.9 μg/g); selenium levels were highest in tarragon (16.5±5.8 μg/g). Zinc levels were similar (p=0.05) in all species tested, as were mercury and lead. The remaining metals (nickel and copper) showed significant differences in uptake, depending on plant species.

Epigenetic Regulation of ZBTB18 Promotes Glioblastoma Progression

PubMed Central

Fedele, Vita; Dai, Fangping; Masilamani, Anie Priscilla; Heiland, Dieter Henrik; Kling, Eva; Gätjens-Sanchez, Ana Maria; Ferrarese, Roberto; Platania, Leonardo; Soroush, Doostkam; Kim, Hyunsoo; Nelander, Sven; Weyerbrock, Astrid; Prinz, Marco; Califano, Andrea; Iavarone, Antonio; Bredel, Markus; Carro, Maria Stella

2018-01-01

Glioblastoma (GBM) is comprised of distinct subtypes characterized by their molecular profile. Mesenchymal identity in GBM has been associated with a comparatively unfavorable prognosis, primarily due to inherent resistance of these tumors to current therapies. The identification of molecular determinants of mesenchymal transformation could potentially allow for the discovery of new therapeutic targets. Zinc Finger and BTB Domain Containing 18 (ZBTB18/ZNF238/RP58) is a zinc finger transcriptional repressor with a crucial role in brain development and neuronal differentiation. Here, ZBTB18 is primarily silenced in the mesenchymal subtype of GBM through aberrant promoter methylation. Loss of ZBTB18 contributes to the aggressive phenotype of glioblastoma through regulation of poor prognosis-associated signatures. Restitution of ZBTB18 expression reverses the phenotype and impairs tumor-forming ability. These results indicate that ZBTB18 functions as a tumor suppressor in GBM through the regulation of genes associated with phenotypically aggressive properties. Implications This study characterizes the role of the putative tumor suppressor ZBTB18 and its regulation by promoter hypermethylation, which appears to be a common mechanism to silence ZBTB18 in the mesenchymal subtype of GBM and provides a new mechanistic opportunity to specifically target this tumor subclass. PMID:28512252

Development of antiproliferative nanohybrid compound with controlled release property using ellagic acid as the active agent

PubMed Central

Hussein, Mohd Zobir; Al Ali, Samer Hasan; Zainal, Zulkarnain; Hakim, Muhammad Nazrul

2011-01-01

An ellagic acid (EA)–zinc layered hydroxide (ZLH) nanohybrid (EAN) was synthesized under a nonaqueous environment using EA and zinc oxide (ZnO) as the precursors. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was 10.4 Å, resulting in the spatial orientation of EA molecules between the interlayers of 22.5° from z-axis with two negative charges at 8,8′ position of the molecules pointed toward the ZLH interlayers. FTIR study showed that the intercalated EA spectral feature is generally similar to that of EA, but with bands slightly shifted. This indicates that some chemical bonding of EA presence between the nanohybrid interlayers was slightly changed, due to the formation of host–guest interaction. The nanohybrid is of mesopores type with 58.8% drug loading and enhanced thermal stability. The release of the drug active, EA from the nanohybrid was found to be sustained and therefore has good potential to be used as a drug controlled-release formulation. In vitro bioassay study showed that the EAN has a mild effect on the hepatocytes cells, similar to its counterpart, free EA. PMID:21796241

Comparative Analysis of Anther Transcriptome Profiles of Two Different Rice Male Sterile Lines Genotypes under Cold Stress.

PubMed

Bai, Bin; Wu, Jun; Sheng, Wen-Tao; Zhou, Bo; Zhou, Li-Jie; Zhuang, Wen; Yao, Dong-Ping; Deng, Qi-Yun

2015-05-18

Rice is highly sensitive to cold stress during reproductive developmental stages, and little is known about the mechanisms of cold responses in rice anther. Using the HiSeq™ 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Pei'ai64S) were analyzed at the fertility sensitive stage under cold stress. Approximately 243 million clean reads were obtained from four libraries and aligned against the oryza indica genome and 1497 and 5652 differentially expressed genes (DEGs) were identified in P64S and Y58S, respectively. Both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for these DEGs. Functional classification of DEGs was also carried out. The DEGs common to both genotypes were mainly involved in signal transduction, metabolism, transport, and transcriptional regulation. Most of the DEGs were unique for each comparison group. We observed that there were more differentially expressed MYB (Myeloblastosis) and zinc finger family transcription factors and signal transduction components such as calmodulin/calcium dependent protein kinases in the Y58S comparison group. It was also found that ribosome-related DEGs may play key roles in cold stress signal transduction. These results presented here would be particularly useful for further studies on investigating the molecular mechanisms of rice responses to cold stress.

Comparative Analysis of Anther Transcriptome Profiles of Two Different Rice Male Sterile Lines Genotypes under Cold Stress

PubMed Central

Bai, Bin; Wu, Jun; Sheng, Wen-Tao; Zhou, Bo; Zhou, Li-Jie; Zhuang, Wen; Yao, Dong-Ping; Deng, Qi-Yun

2015-01-01

Rice is highly sensitive to cold stress during reproductive developmental stages, and little is known about the mechanisms of cold responses in rice anther. Using the HiSeq™ 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Pei’ai64S) were analyzed at the fertility sensitive stage under cold stress. Approximately 243 million clean reads were obtained from four libraries and aligned against the oryza indica genome and 1497 and 5652 differentially expressed genes (DEGs) were identified in P64S and Y58S, respectively. Both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for these DEGs. Functional classification of DEGs was also carried out. The DEGs common to both genotypes were mainly involved in signal transduction, metabolism, transport, and transcriptional regulation. Most of the DEGs were unique for each comparison group. We observed that there were more differentially expressed MYB (Myeloblastosis) and zinc finger family transcription factors and signal transduction components such as calmodulin/calcium dependent protein kinases in the Y58S comparison group. It was also found that ribosome-related DEGs may play key roles in cold stress signal transduction. These results presented here would be particularly useful for further studies on investigating the molecular mechanisms of rice responses to cold stress. PMID:25993302

Development, validity, and reliability of a food frequency questionnaire for antioxidants in elderly Iranian people

PubMed Central

Malekahmadi, Mahsa; Naeini, Amirmansour Alavi; Shab-Bidar, Sakineh; Feizi, Awat; Djazayery, Abolghasem

2016-01-01

Background: The food frequency questionnaire (FFQ), as a way to assess the dietary intake in comparison with other methods, is easier to analyze and takes less time and is less costly. Our aim in this study was to develop and validate an FFQ for estimating the intakes of selected antioxidants in elderly Iranian people. Materials and Methods: A total of 185 elderly people were randomly selected. Three-day food records were completed by the subjects and collected every 2 months and dietary intake levels of zinc, selenium, carotenes and vitamins C and E were estimated. Based on the food records data, geographic location, and age, an FFQ was designed to estimate antioxidant intakes during 1 year. In addition, for controlling energy intake, 2-day food records were also collected with the food frequency questionnaire. To assess the reliability, 40 individuals were asked to complete the FFQ twice with an interval of 3 months in between. Results: Intraclass correlation coefficient (ICC) between the two FFQs for antioxidant C, antioxidant E, carotene, selenium, and zinc were 0.62, 0.47, 0.51, 0.54, and 0.58, respectively (P < 0.05). In addition, Pearson correlation coefficients between the FFQ and the food records, after controlling energy for vitamin C, vitamin E, carotene, selenium, and zinc, were 0.46, 0.48, 0.38, 0.55, and 0.47 respectively (P < 0.001). Conclusion: According to the results of this study, considering the fact that the FFQ was designed for the elderly and the special conditions (patience, memory, etc.) and vulnerability of this age group, the questionnaire is relatively valid and reliable to use. PMID:27904560

Enhanced synergism of antibiotics with zinc oxide nanoparticles against extended spectrum β-lactamase producers implicated in urinary tract infections

NASA Astrophysics Data System (ADS)

Bhande, Rashmi M.; Khobragade, C. N.; Mane, R. S.; Bhande, S.

2013-01-01

In this study, enhanced synergistic bioactivity of zinc oxide nanoparticles (ZnO NPs) with β-lactam antibiotics were evaluated against a panel of clinically isolated extended spectrum β-lactamase producers implicated in urinary tract infections. Chemically synthesized zinc oxide nanoparticles (15 nm) were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmittance electron microscopy (HR-TEM), selective area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and UV-Visible spectrophotometry techniques. The antimicrobial potency (10 ± 0.66, 12, 11.33 ± 1.10, and 0.7 ± 0.66 mm inhibiting zone) and minimum inhibitory concentrations (80, 60, 30, 50 μg/ml) of ZnO NPs were tested separately whereas time-kill and membrane leakage assays were evaluated in combination with ZnO NPs+ cefotaxime, ampicillin, ceftriaxone, cefepime against the β-lactamase producer strains of E. coli, K. pneumoniae, S. paucimobilis, and P. aeruginosa, respectively. Time-kill curve dynamics of ZnO NPs with β-lactam antibiotics revealed enhanced bactericidal activity (50, 85, 58, 50 % fold inhibition) by delaying the exponential and stationary phases of all isolates when tested separately. Posttime-kill effect was studied on cell membrane by assaying leakage of reducing sugars (130.2, 124.7, 137, and 115.8 μg/bacterial dry weight of 1 mg (μg/mg) and proteins (15, 10, 16, 18 μg/mg). These assays revealed that membrane leakage was due to synergism of ZnO NPs+ β-lactam antibiotics which successfully damage cell membrane thereby leading to death of all ESBL producers. The results demonstrate the utilization of ZnO NPs as a potentiator of β-lactam antibiotics and suggest the possibility to use nanoparticles in a combination therapy to treat UTI.

[Hygienic substantiation of application of functional dairy products in the prevention of macro- and micronutrient deficiency].

PubMed

Boyarskaya, L A; Vil’ms, E A; Turchaninov, D V; Bogdashin, I V; Erofeev, Yu V

Based on the study of actual nutrition and availability of macroelements there was found that adult population of the city of Omsk was established to refer to the group at risk for the development of micronutrient deficiency associated with low content of a set of essential elements (copper, zinc, calcium, selenium) in the ration, being prior for correction.There was executed the hygienic substantiation developed the fermented acid milk bioproduct of a functional purpose "Bifidin" enriched with micronutrients, prior for the population of the Omsk region. Introduction of this bio-product into the ration allows to effectively correct disorders of the mineral status, that was manifested in a decline in the proportion of patients with insufficiency of calcium (from 37.9 to 24.1%; p = 0.013), copper (from 51.7 to 25.9%; p = 0.004), selenium (from 96.6 to 84.5%; p = 0.026), zinc (from 58.6 to 48.3% of the subjects; p = 0.264). Upon the completion of the prophylactic course (intake "Bifidin" of 200 ml for 60 days), there was noted the gain in the concentration in hair: calcium (by 24.4%; p=0.441), zinc (by 8.0%; p=0.0008), copper (by 8.8%; p < 0.001), selenium (by 41.5%; p < 0.001). There was established the efficacy of the use of bio-product "Bifidin" enriched with micronutrients for the improvement of the structure of nutrition and element status of the adult population of the city of Omsk. There was justified the extensive use of dairy products enriched with micronutrients both for the reduction of the prevalence of microelementoses and the improvement of the nutritional status.

Effects of zinc deficiency and zinc supplementation on homocysteine levels and related enzyme expression in rats.

PubMed

Jing, Mingyan; Rech, Leslie; Wu, Yinghong; Goltz, Douglas; Taylor, Carla G; House, James D

2015-04-01

Methionine synthase (MS) and betaine-homocysteine methyltransferase (BHMT) are both zinc (Zn)-dependent methyltransferases and involved in the methylation of homocysteine. The objective of this study was to investigate the effects of dietary Zn supply on homocysteine levels and expression of the two enzymes in growing rats. Male weanling Sprague-Dawley rats were assigned randomly to four dietary groups (n=8/group) for 3 weeks: Zn deficient (ZD; <1mg Zn/kg); Zn control (ZC; 30mg Zn/kg); Zn supplemented (ZS; 300mg Zn/kg); pair fed (PF; 30mg Zn/kg) to the ZD group. Serum and femur Zn concentrations were 83% and 58% lower in ZD, and 49% and 62% higher in ZS compared to ZC (P<0.001), respectively. The ZD rats had lower feed intake (37%), body weight gains (45%), liver (43%) and kidney (31%) weights than those of ZC (P<0.001), but these parameters in ZD were not significantly different from the PF controls. Serum homocysteine concentrations were 65% higher in ZD compared to PF (P<0.05), and there was no significant difference in serum folate levels between ZD and PF groups. The mRNA expression of liver and kidney MS was 57% and 38% lower in ZD than PF (P<0.001), respectively. Hepatic and renal BHMT mRNA levels were not altered in ZD compared to controls. The aforementioned measurements were not significantly different between ZS and ZC groups, except Zn levels. These results demonstrated that homocysteine homeostasis appeared to be disturbed by Zn deficiency but not Zn supplementation, and elevated serum homocysteine might be due to reduced expression of MS during Zn deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

Revealing Ligand Binding Sites and Quantifying Subunit Variants of Noncovalent Protein Complexes in a Single Native Top-Down FTICR MS Experiment

NASA Astrophysics Data System (ADS)

Li, Huilin; Wongkongkathep, Piriya; Van Orden, Steve L.; Ogorzalek Loo, Rachel R.; Loo, Joseph A.

2014-12-01

"Native" mass spectrometry (MS) has been proven to be increasingly useful for structural biology studies of macromolecular assemblies. Using horse liver alcohol dehydrogenase (hADH) and yeast alcohol dehydrogenase (yADH) as examples, we demonstrate that rich information can be obtained in a single native top-down MS experiment using Fourier transform ion cyclotron mass spectrometry (FTICR MS). Beyond measuring the molecular weights of the protein complexes, isotopic mass resolution was achieved for yeast ADH tetramer (147 kDa) with an average resolving power of 412,700 at m/z 5466 in absorption mode, and the mass reflects that each subunit binds to two zinc atoms. The N-terminal 89 amino acid residues were sequenced in a top-down electron capture dissociation (ECD) experiment, along with the identifications of the zinc binding site at Cys46 and a point mutation (V58T). With the combination of various activation/dissociation techniques, including ECD, in-source dissociation (ISD), collisionally activated dissociation (CAD), and infrared multiphoton dissociation (IRMPD), 40% of the yADH sequence was derived directly from the native tetramer complex. For hADH, native top-down ECD-MS shows that both E and S subunits are present in the hADH sample, with a relative ratio of 4:1. Native top-down ISD of the hADH dimer shows that each subunit (E and S chains) binds not only to two zinc atoms, but also the NAD/NADH ligand, with a higher NAD/NADH binding preference for the S chain relative to the E chain. In total, 32% sequence coverage was achieved for both E and S chains.

The content of elements in rainwater and its relation to the frequency of hospitalization for chronic lymphocytic leukemia and chronic myeloid leukemia in Opole Voivodship, Poland, during 2000-2002.

PubMed

Szyguła, Renata; Bunio, Andrzej; Tubek, Sławomir

2011-06-01

Environmental factors play an essential role in the etiology of diseases of the hematopoietic system. Such factors include soil and water pollution and the presence of metals and toxic compounds in the air. Measuring the content of metallic elements in rainwater has become an accepted procedure for environmental pollution monitoring. In accordance with the above, it was decided to study relations between the content of selected elements in rainwater and hospitalization frequency due to chronic lymphocytic leukemia (CLL, C91 on ICD-10) and chronic myeloid leukemia (CML, C92 on ICD-10). It can be assumed that hospitalization frequency is a reliable indicator of exacerbations of these diseases. The annual average of hospitalizations due to a given disease during the years 2000-2002 was correlated with the annual average content of a given element in rainwater using the Spearman's correlation indicator to describe the relationship between the element content and the disease that is possibly a consequence of the element's presence in rainwater. In cases of CLL for all the subjected population and for men, no statistically significant correlations were found. For women, statistically significant correlations were found for chromium (r = 0.66), lead (r = 0.58), copper (r = 0.58), and cadmium (r = 0.51). For CML in all the studied population significant, negative correlations were found for magnesium (r = -0.6) and zinc (r = -0.52). In men, significant negative correlations were seen for magnesium (r = -0.69 and zinc (r = -0.55). No significant correlations were found in women. These results indicate the need of taking into account the environmental and gender factors in research connected with these diseases, which can be probably of help in improvements of therapy efficiency.

Sol-gel synthesis and in vitro bioactivity of copper and zinc-doped silicate bioactive glasses and glass-ceramics.

PubMed

Bejarano, Julian; Caviedes, Pablo; Palza, Humberto

2015-03-11

Metal doping of bioactive glasses based on ternary 60SiO2-36CaO-4P2O5 (58S) and quaternary 60SiO2-25CaO-11Na2O-4P2O5 (NaBG) mol% compositions synthesized using a sol-gel process was analyzed. In particular, the effect of incorporating 1, 5 and 10 mol% of CuO and ZnO (replacing equivalent quantities of CaO) on the texture, in vitro bioactivity, and cytocompatibility of these materials was evaluated. Our results showed that the addition of metal ions can modulate the textural property of the matrix and its crystal structure. Regarding the bioactivity, after soaking in simulated body fluid (SBF) undoped 58S and NaBG glasses developed an apatite surface layer that was reduced in the doped glasses depending on the type of metal and its concentration with Zn displaying the largest inhibitions. Both the ion release from samples and the ion adsorption from the medium depended on the type of matrix with 58S glasses showing the highest values. Pure NaBG glass was more cytocompatible to osteoblast-like cells (SaOS-2) than pure 58S glass as tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The incorporation of metal ions decreased the cytocompatibility of the glasses depending on their concentration and on the glass matrix doped. Our results show that by changing the glass composition and by adding Cu or Zn, bioactive materials with different textures, bioactivity and cytocompatibility can be synthesized.

Nutrition Concerns of Insufficient and Excessive Intake of Dietary Minerals in Lactating Women: A Cross-Sectional Survey in Three Cities of China

PubMed Central

Zhao, Ai; Xue, Yong; Zhang, Yumei; Li, Wenjun; Yu, Kai; Wang, Peiyu

2016-01-01

Objective Objectives of this study were 1) to investigate the mineral intake by Chinese lactating women, 2) to explore the dietary source of minerals, and 3) the ratios between different dietary minerals. Methods A total of 468 lactating women in 5–240 days post-partum participated in this study. Food intakes by participants were measured using one time of 24-hour dietary recall, and minerals from food were calculated based on the Chinese Food Composition Table, second edition. Results In post-partum, women had inadequate food intake. 81.0% of women’s daily intake of dairy products was lower than 300g, and 97.1% of women’s daily intake of salt over 6g. For mineral intake, there were 81.8%, 59.0%, 47.6%, 45.7% and 66.8% of women’s calcium, magnesium, iron, zinc and selenium intake lower than the estimated average requirement, respectively, and 91.7% of women’s excessive intake of sodium. The calcium/phosphorus and sodium/potassium ratios were 0.41±0.26/1 and 3.13±2.89/1, respectively. Considering the dietary sources of minerals, 27.3%, 25.3% and 30.1% of iron, zinc and calcium were from animal-based food, respectively, and 60.3%, 66.1% and 58.0% of iron, zinc and calcium were from plant-based food, respectively. The phosphorus-protein ratio was 0.014±0.003/1. Lactation stage was associated with nutrient intake. Women within 30 days post-partum and the ones who live in Guangzhou had a significantly lower intake of certain minerals, while women with a high education experience had a high intake of calcium, potassium, iron and zinc. Productive age, whether obese or not, and delivery ways were not associated with mineral intakes (P all >0.05). Conclusion Chinese women in three studied cities had an inappropriate food intake and resulted in both insufficient and excessive intakes of certain minerals. PMID:26730592

Epigenetic Regulation of ZBTB18 Promotes Glioblastoma Progression.

PubMed

Fedele, Vita; Dai, Fangping; Masilamani, Anie P; Heiland, Dieter H; Kling, Eva; Gätjens-Sanchez, Ana M; Ferrarese, Roberto; Platania, Leonardo; Soroush, Doostkam; Kim, Hyunsoo; Nelander, Sven; Weyerbrock, Astrid; Prinz, Marco; Califano, Andrea; Iavarone, Antonio; Bredel, Markus; Carro, Maria S

2017-08-01

Glioblastoma (GBM) comprises distinct subtypes characterized by their molecular profile. Mesenchymal identity in GBM has been associated with a comparatively unfavorable prognosis, primarily due to inherent resistance of these tumors to current therapies. The identification of molecular determinants of mesenchymal transformation could potentially allow for the discovery of new therapeutic targets. Zinc Finger and BTB Domain Containing 18 (ZBTB18/ZNF238/RP58) is a zinc finger transcriptional repressor with a crucial role in brain development and neuronal differentiation. Here, ZBTB18 is primarily silenced in the mesenchymal subtype of GBM through aberrant promoter methylation. Loss of ZBTB18 contributes to the aggressive phenotype of glioblastoma through regulation of poor prognosis-associated signatures. Restitution of ZBTB18 expression reverses the phenotype and impairs tumor-forming ability. These results indicate that ZBTB18 functions as a tumor suppressor in GBM through the regulation of genes associated with phenotypically aggressive properties. Implications: This study characterizes the role of the putative tumor suppressor ZBTB18 and its regulation by promoter hypermethylation, which appears to be a common mechanism to silence ZBTB18 in the mesenchymal subtype of GBM and provides a new mechanistic opportunity to specifically target this tumor subclass. Mol Cancer Res; 15(8); 998-1011. ©2017 AACR . ©2017 American Association for Cancer Research.

Williamson-Hall analysis and optical properties of small sized ZnO nanocrystals

NASA Astrophysics Data System (ADS)

Kalita, Amarjyoti; Kalita, Manos P. C.

2017-08-01

We apply Williamson-Hall (WH) method of X-ray diffraction (XRD) line profile analysis for lattice strain estimation of small sized ZnO nanocrystals (crystallite size≈4 nm). The ZnO nanocrystals are synthesized by room temperature chemical co-precipitation followed by heating at 40 °C. Zinc acetate, sodium hydroxide and 2-mercaptoethanol (ME) are used for the synthesis of the nanocrystals. {100}, {002}, {101} and {200}, {112}, {201} line profiles in the XRD pattern are significantly merged, therefore determination of the full width at half maximum values and peak positions of the line profiles required for WH analysis has been carried out by executing Rietveld refinement of the XRD pattern. Lattice strain of the 4 nm sized ZnO nanocrystals is found to be 5.8×10-3 which is significantly higher as compared to the literature reported values for larger ones (crystallite size≈17-47 nm). Role of ME as capping agent is confirmed by Fourier transform infrared spectroscopy. The band gap of the nanocrystals is determined from the UV-Visible absorption spectrum and is found to be 3.68 eV. The photoluminescence spectrum exhibits emissions in the visible (408 nm-violet, 467 nm-blue and 538 nm-green) regions showing presence of zinc interstitial and oxygen vacancy in the ZnO nanocrystals.

Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

NASA Astrophysics Data System (ADS)

Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

2017-12-01

Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

New insight into atmospheric mercury emissions from zinc smelters using mass flow analysis.

PubMed

Wu, Qingru; Wang, Shuxiao; Hui, Mulin; Wang, Fengyang; Zhang, Lei; Duan, Lei; Luo, Yao

2015-03-17

The mercury (Hg) flow paths from three zinc (Zn) smelters indicated that a large quantity of Hg, approximately 38.0-57.0% of the total Hg input, was stored as acid slag in the landfill sites. Approximately 15.0-27.1% of the Hg input was emitted into water or stored as open-dumped slags, and 3.3-14.5% of the Hg input ended in sulfuric acid. Atmospheric Hg emissions, accounting for 1.4-9.6% of the total Hg input, were from both the Zn production and waste disposal processes. Atmospheric Hg emissions from the waste disposal processes accounted for 40.6, 89.6, and 94.6% of the total atmospheric Hg emissions of the three studied smelters, respectively. The Zn production process mainly contributed to oxidized Hg (Hg2+) emissions, whereas the waste disposal process generated mostly elemental Hg (Hg0) emissions. When the emissions from these two processes are considered together, the emission proportion of the Hg2+ mass was 51, 46, and 29% in smelters A, B, and C, respectively. These results indicated that approximately 10.8±5.8 t of atmospheric Hg emissions from the waste disposal process were ignored in recent inventories. Therefore, the total atmospheric Hg emissions from the Zn industry of China should be approximately 50 t.

Selenium, zinc, copper, Cu/Zn ratio and total antioxidant status in the serum of vitiligo patients treated by narrow-band ultraviolet-B phototherapy.

PubMed

Wacewicz, Marta; Socha, Katarzyna; Soroczyńska, Jolanta; Niczyporuk, Marek; Aleksiejczuk, Piotr; Ostrowska, Jolanta; Borawska, Maria H

2018-03-01

Vitiligo is a chronic, depigmenting skin disorder, whose pathogenesis is still unknown. Narrow band ultraviolet-B (NB-UVB) is now one of the most widely used treatment of vitiligo. It was suggested that trace elements may play a role in pathogenesis of vitiligo. The aim of this study was to estimate the concentration of selenium (Se), zinc (Zn), copper (Cu) and Cu/Zn ratio as well as total antioxidant status (TAS) in the serum of patients with vitiligo. We assessed 50 patients with vitiligo and 58 healthy controls. Serum levels of Se, Zn and Cu were determined by the atomic absorption spectrometry method, and the Cu/Zn ratio was also calculated. TAS in serum was measured spectrophotometrically. Serum concentration of Se in patients with vitiligo before and after phototherapy was significantly lower as compared to the control group. Zn level in the serum of patients decreased significantly after phototherapy. We observed higher Cu/Zn ratio (p < .05) in examined patients than in the control group and after NB-UVB. We have found decrease in TAS in the serum of vitiligo patients after NB-UVB. The current study showed some disturbances in the serum levels of trace elements and total antioxidant status in vitiligo patients.

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

Anionic 11-mercaptoundecanoic acid capped ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Šimšíková, Michaela; Antalík, Marián; Kaňuchová, Mária; Škvarla, Jiří

2013-10-01

The anionic zinc oxide nanoparticles have been prepared at room temperature by a precipitation method using ZnCl2 and NaOH and surface modification with 11-mercaptoundecanoic acid (MUA). Atomic force microscopy (AFM) was used for definition of morphology and size of prepared nanoparticles which was proved by measurements of particle size distribution using Zetasizer. Successful coating with MUA as surfactant was acknowledged by X-ray photoelectron spectroscopy and ATR FT-IR spectroscopy. The isoelectric point (IEP) of ZnO-MUA nanoparticles was obtained by measurements of zeta potential and FT-IR dependence on pH; the obtained value was approximately 3.58. The value of exchanged protons was 2.88 which indicates a positive binding cooperativity of modified nanoparticles.

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

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 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.

A novel GATA3 nonsense mutation in a newly diagnosed adult patient of hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome.

PubMed

Nanba, Kazutaka; Usui, Takeshi; Nakamura, Michikazu; Toyota, Yuko; Hirota, Keisho; Tamanaha, Tamiko; Kawashima, Sachiko-Tsukamoto; Nakao, Kanako; Yuno, Akiko; Tagami, Tetsuya; Naruse, Mitsuhide; Shimatsu, Akira

2013-01-01

Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is an autosomal dominant disorder caused by a GATA3 gene mutation. Here we report a novel mutation of GATA3 in a patient diagnosed with HDR syndrome at the age of 58 with extensive intracranial calcification. A 58-year-old Japanese man showed severe hypocalcemia and marked calcification in the basal ganglia, cerebellum, deep white matter, and gray-white junction on computed tomography (CT). The serum intact parathyroid hormone level was relatively low against low serum calcium concentration. The patient had been diagnosed with bilateral sensorineural deafness in childhood and had a family history of hearing disorders. Imaging studies revealed no renal anomalies. The patient was diagnosed with HDR syndrome, and genetic testing was performed. Genetic analysis of GATA3 showed a novel nonsense mutation at codon 198 (S198X) in exon 3. The S198X mutation leads to a loss of two zinc finger deoxyribonucleic acid (DNA) binding domains and is considered to be responsible for HDR syndrome. We identified a novel nonsense mutation of GATA3 in an adult patient with HDR syndrome who showed extensive intracranial calcification.

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

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.

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

Rising intracellular zinc by membrane depolarization and glucose in insulin-secreting clonal HIT-T15 beta cells.

PubMed

Slepchenko, Kira G; Li, Yang V

2012-01-01

Zinc (Zn(2+)) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30-60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

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

Adherence to treatment guidelines for acute diarrhoea in children up to 12 years in Ujjain, India - a cross-sectional prescription analysis

PubMed Central

2011-01-01

Background Diarrhoea accounts for 20% of all paediatric deaths in India. Despite WHO recommendations and IAP (Indian Academy of Paediatrics) and Government of India treatment guidelines, few children suffering from acute diarrhoea in India receive low osmolarity oral rehydration solution (ORS) and zinc from health care providers. The aim of this study was to analyse practitioners' prescriptions for acute diarrhoea for adherence to treatment guidelines and further to determine the factors affecting prescribing for diarrhoea in Ujjain, India. Methods This cross-sectional study was conducted in pharmacies and major hospitals of Ujjain, India. We included prescriptions from all practitioners, including those from modern medicine, Ayurveda, Homeopathy as well as informal health-care providers (IHPs). The data collection instrument was designed to include all the possible medications that are given for an episode of acute diarrhoea to children up to 12 years of age. Pharmacy assistants and resident medical officers transferred the information regarding the current diarrhoeal episode and the treatment given from the prescriptions and inpatient case sheets, respectively, to the data collection instrument. Results Information was collected from 843 diarrhoea prescriptions. We found only 6 prescriptions having the recommended treatment that is ORS along with Zinc, with no additional probiotics, antibiotics, racecadotril or antiemetics (except Domperidone for vomiting). ORS alone was prescribed in 58% of the prescriptions; while ORS with zinc was prescribed in 22% of prescriptions, however these also contained other drugs not included in the guidelines. Antibiotics were prescribed in 71% of prescriptions. Broad-spectrum antibiotics were prescribed and often in illogical fixed-dose combinations. One such illogical combination, ofloxacin with ornidazole, was the most frequent oral antibiotic prescribed (22% of antibiotics prescribed). Practitioners from alternate system of medicine and IHPs are significantly less likely (OR 0.13, 95% CI 0.04-0.46, P = 0.003) to prescribe ORS and zinc than pediatricians. Practitioners from 'free' hospitals are more likely to prescribe ORS and zinc (OR 4.94, 95% CI 2.45-9.96, P < 0.001) and less likely to prescribe antibiotics (OR 0.01, 95% CI 0.01-0-04, P < 0.001) compared to practitioners from 'charitable' hospitals. Accompanying symptoms like the presence of fever, pain, blood in the stool and vomiting significantly increased antibiotic prescribing. Conclusion This study demonstrated low adherence to standard treatment guidelines for management of acute diarrhoea in children under 12 years in Ujjain, India. Key public health concerns were the low use of zinc and the high use of antibiotics, found in prescriptions from both specialist paediatricians as well as practitioners from alternate systems of medicine and informal health-care providers. To improve case management of acute diarrhoea, continuing professional development programme targeting the practitioners of all systems of medicine is necessary. PMID:21276243

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.

Rising Intracellular Zinc by Membrane Depolarization and Glucose in Insulin-Secreting Clonal HIT-T15 Beta Cells

PubMed Central

Slepchenko, Kira G.; Li, Yang V.

2012-01-01

Zinc (Zn2+) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30–60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells. PMID:22536213

[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

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.

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

Environmental implications of element emissions from phosphate-processing operations in southeastern Idaho

USGS Publications Warehouse

Severson, R.C.; Gough, L.P.

1979-01-01

In order to assess the contribution to plants and soils of certain elements emitted by phosphate processing, we sampled sagebrush, grasses, and A- and C-horizon soils along upwind and downwind transects at Pocatello and Soda Springs, Idaho. Analyses for 70 elements in plants showed that, statistically, the concentration of 7 environmentally important elements, cadmium, chromium, fluorine, selenium, uranium, vanadium, and zinc, were related to emissions from phosphate-processing operations. Two additional elements, lithium and nickel, show probable relationships. The literature on the effects of these elements on plant and animal health is briefly surveyed. Relations between element content in plants and distance from the phosphate-processing operations were stronger at Soda Springs than at Pocatello and, in general, stronger in sagebrush than in the grasses. Analyses for 58 elements in soils showed that, statistically, beryllium, fluorine, iron, lead, lithium, potassium, rubidium, thorium, and zinc were related to emissions only at Pocatello and only in the A horizon. Moreover, six additional elements, copper, mercury, nickel, titanium, uranium, and vanadium, probably are similarly related along the same transect. The approximate amounts of elements added to the soils by the emissions are estimated. In C-horizon soils, no statistically significant relations were observed between element concentrations and distance from the processing sites. At Soda Springs, the nonuniformity of soils at the sampling locations may have obscured the relationship between soil-element content and emissions from phosphate processing.

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

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 Signals and Immunity.

PubMed

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

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.

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

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

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

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

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.

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.

Laboratory strength of glass ionomer and zinc phosphate cements.

PubMed

Piwowarczyk, A; Ottl, P; Lauer, H C

2001-09-01

The present in vitro study examined 3 mechanical properties, namely compressive, flexural, and diametral tensile strength, of various commercially available cements and core materials as a function of time after mixing. The examined materials were 2 cermet cements (Ketac Silver [ESPE, Seefeld, Germany] and Chelon Silver [ESPE]), 1 metal-reinforced glass ionomer cement (Miracle Mix [GC Dental Industrial Corp, Tokyo, Japan]), 2 conventional glass ionomer cements (Ketac Bond [ESPE] and Ketac Cem [ESPE]), 1 standard cure zinc phosphate cement (Harvard Cement [Richter and Hoffmann, Berlin, Germany]), and 1 zinc phosphate cement with the addition of 30% silver amalgam alloy powder (Harvard Cement 70% with Dispersalloy 30% [Richter and Hoffmann/Johnson and Johnson, East Windsor, NJ]). Properties were measured using a universal testing machine at 15 minutes, 1 hour, and 24 hours after first mixing. Compressive strengths varied widely between the 3 times of measurement from 5.8 +/- 6.6 MPa for Ketac Cem to 144.3 +/- 10.2 MPa for Ketac Silver. Twenty-four hours after mixing, the Bonferroni test showed significant (p

Sublethal Toxicity Endpoints of Heavy Metals to the Nematode Caenorhabditis elegans

PubMed Central

Wu, Yue; Wang, Qiang; Li, Huixin

2016-01-01

Caenorhabditis elegans, a free-living nematode, is commonly used as a model organism in ecotoxicological studies. The current literatures have provided useful insight into the relative sensitivity of several endpoints, but few direct comparisons of multiple endpoints under a common set of experimental conditions. The objective of this study was to determine appropriate sublethal endpoints to develop an ecotoxicity screening and monitoring system. C. elegans was applied to explore the sublethal toxicity of four heavy metals (copper, zinc, cadmium and chromium). Two physiological endpoints (growth and reproduction), three behavioral endpoints (head thrash frequency, body bend frequency and feeding) and two enzymatic endpoints (acetylcholine esterase [AChE] and superoxide dismutase [SOD]) were selected for the assessment of heavy metal toxicity. The squared correlation coefficients (R2) between the responses observed and fitted by Logit function were higher than 0.90 and the RMSE were lower than 0.10, indicating a good significance statistically. There was no significant difference among the half effect concentration (EC50) endpoints in physiological and behavioral effects of the four heavy metals, indicating similar sensitivity of physiological and behavioral effects. AChE enzyme was more sensitive to copper, zinc, and cadmium than to other physiological and behavioral effects, and SOD enzyme was most sensitive to chromium. The EC50 of copper, zinc, and cadmium, to the AChE enzyme in the nematodes were 0.68 mg/L, 2.76 mg/L, and 0.92 mg/L respectively and the EC50 of chromium to the SOD enzyme in the nematode was 1.58 mg/L. The results of this study showed that there was a good concentration-response relationship between all four heavy metals and the sublethal toxicity effects to C. elegans. Considering these sublethal endpoints in terms of simplicity, accuracy, repeatability and costs of the experiments, feeding is the relatively ideal sublethal toxicity endpoint of heavy metals to C. elegans. PMID:26824831

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

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.

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.

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.

[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.

Zinc Signals and Immunity

PubMed Central

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-01-01

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as “zinc waves”, and late homeostatic zinc signals regarding prolonged changes in intracellular zinc. PMID:29064429

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...

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

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.

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.

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.

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.

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

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.

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.

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

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

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.

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.

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.

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.

Zinc Transport Differs in Rat Spermatogenic Cell Types and Is Affected by Treatment with Cyclophosphamide1

PubMed Central

Downey, Anne Marie; Hales, Barbara F.; Robaire, Bernard

2016-01-01

Adequate zinc levels are required for proper cellular functions and for male germ cell development. Zinc transport is accomplished by two families of zinc transporters, the ZIPs and the ZnTs, that increase and decrease cytosolic zinc levels, respectively. However, very little is known about zinc transport in the testis. Furthermore, whether cytotoxic agents such as cyclophosphamide (CPA), a known male germ cell toxicant, can affect zinc transport and homeostasis is unknown. We examined zinc transporter expression and zinc transport in pachytene spermatocytes (PS) and round spermatids (RS) in a normal state and after exposure to CPA. We observed differences in the expression of members of the ZnT and ZIP families in purified populations of PS and RS. We also observed that RS accumulate more zinc over time than PS. The expression of many zinc binding genes was altered after CPA treatment. Interestingly, we found that the expression levels of ZIP5 and ZIP14 were increased in PS from animals treated daily with 6 mg/kg CPA for 4 wk but not in RS. This up-regulation led to an increase in zinc uptake in PS but not in RS from treated animals compared to controls. These data suggest that CPA treatment may alter zinc homeostasis in male germ cells leading to an increased need for zinc. Altered zinc homeostasis may disrupt proper germ cell development and contribute to infertility and effects on progeny. PMID:27281708

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

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.

Trace element intakes and dietary phytate/Zn and Ca x phytate/Zn millimolar ratios of periurban Guatemalan women during the third trimester of pregnancy.

PubMed

Fitzgerald, S L; Gibson, R S; Quan de Serrano, J; Portocarrero, L; Vasquez, A; de Zepeda, E; Lopez-Palacios, C Y; Thompson, L U; Stephen, A M; Solomons, N W

1993-02-01

Repeated 24-h recalls (9-14/subject) were conducted on 52 periurban Guatemalan pregnant women aged 25 +/- 5 y (means +/- SD). Intakes of energy, protein, calcium, zinc, copper, manganese, nonstarch polysaccharide (NSP), phytate, and millimolar ratios of phytate to zinc and (calcium x phytate) to zinc were calculated from food-composition values on the basis of chemical analysis and the literature. Mean (+/- SD) daily intakes were as follows: energy 8694 +/- 1674 kJ, protein 63.0 +/- 13.3 g, calcium 727 +/- 163, zinc 11.3 +/- 2.7, copper 1.3 +/- 0.3, manganese 2.8 +/- 0.6, phytate 2254 +/- 773 mg/d, NSP 26.6 +/- 6.9 g, phytate/zinc 18.8 +/- 4.2, (calcium x phytate)/zinc 706 +/- 21 mmol/MJ. Ninety-four percent had zinc intakes below the recommendations (15 mg) of WHO and the US recommended dietary allowances, assuming 20% absorption. Tortillas were a major source of zinc (46%), copper (20%), manganese (23%), calcium (39%), phytate (68%), and NSP (50%); 19% zinc from flesh foods. Thirty-eight percent had phytate-zinc ratios > 20; 94% had millimolar ratios of (calcium x phytate) to zinc per MJ > or = 22. The high prevalence of millimolar ratios of phytate to zinc and (calcium x phytate) to zinc per MJ above 20 and 22, respectively, may compromise zinc nutriture.

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.

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.

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. ...

Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly:A randomized double-blind placebo-controlled trial

USDA-ARS?s Scientific Manuscript database

Background: Zinc is essential for the regulation of immune response. T cell function declines with age. Zinc supplementation has the potential to improve serum zinc concentrations and immunity of nursing home elderly with low serum zinc concentration. Objective: We aimed to determine the effect of ...

Zinc uptake and regulation by the sublittoral prawn Pandalus montagui (Crustacea: Decapoda)

NASA Astrophysics Data System (ADS)

Nugegoda, D.; Rainbow, P. S.

1988-06-01

The sublittoral decapod crustacean Pandalus montagui Leach in artificial seawater at 10°C regulates the total body zinc concentration to a constant level in dissolved zinc concentrations up to ca. 22 μg Zn l -1, beyond which there is net accumulation of body zinc. This threshold of zinc regulation breakdown is lower than that in the littoral decapods Palaemon elegans (ca. 93 μg Zn l -1) and Palaemonetes varians (ca. 190 μg Zn l -1) under the same physico-chemical conditions. Correspondingly, zinc uptake rates of the three species of decapods decrease in the order P. montagui > P. elegans > P. varians. It is concluded that regulation of total body zinc concentration is more efficient in decapods adapted to the fluctuating environments of littoral habitats, possibly as a result of changes in permeability of uptake surfaces in combination with improved zinc excretion systems. The moult cycle is important in determining the ability of an individual prawn to regulate zinc. Body zinc in Pandalus montagui consists of at least two pools of zinc exchanging at different rates which the environment. Zinc and copper are not evenly distributed in the tissues of P. montagui.

Studies on the bioavailability of zinc in humans: intestinal interaction of tin and zinc.

PubMed

Solomons, N W; Marchini, J S; Duarte-Favaro, R M; Vannuchi, H; Dutra de Oliveira, J E

1983-04-01

Mineral/mineral interactions at the intestinal level are important in animal nutrition and toxicology, but only limited understanding of their extent or importance in humans has been developed. An inhibitory interaction of dietary tin on zinc retention has been recently described from human metabolic studies. We have explored the tin/zinc interaction using the change-in-plasma-zinc-concentration method with a standard dosage of 12.5 mg of zinc as zinc sulfate in 100 ml of Coca-Cola. Sn/Zn ratios of 2:1, 4:1, and 8:1, constituted by addition of 25, 50, and 100 mg of tin as stannous chloride, had no significant overall effect on zinc uptake. The 100-mg dose of tin produced noxious gastrointestinal symptoms. Addition of iron as ferrous sulfate to form ratios of Sn/Fe/Zn of 1:1:1 and 2:2:1 with the standard zinc solution and the appropriate doses of tin produced a reduction of zinc absorption not dissimilar from that seen previously with zinc and iron alone, and addition of picolinic acid did not influence the uptake of zinc from the solution with the 2:2:1 Sn/Fe/Zn ratio.

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.

Factors influencing zinc status of apparently healthy indians.

PubMed

Agte, Vaishali V; Chiplonkar, Shashi A; Tarwadi, Kirtan V

2005-10-01

To identify dietary, environmental and socio-economic factors associated with mild zinc deficiency, three zinc status indices; erythrocyte membrane zinc (RBCMZn), plasma zinc and super oxide dismutase (SOD) were assessed in free living and apparently healthy Indian population. Dietary patterns of 232 men and 223 women (20-65 yr) from rural, industrial and urban regions of Western India were evaluated by food frequency questionnaire. RBCMZn was estimated using atomic absorption spectrometry, hemoglobin and serum ceruloplasmin by spectrophotometer. On a sub sample (48 men and 51 women) plasma zinc and SOD were also assessed. Mean RBCMZn was 0.5 +/- 0.1 micromols/g protein with 46% individuals showing zinc deficiency. Mean plasma zinc was 0.98 +/- 0.12 microg/mL with 25% men and 2.5% women having values below normal range. Mean SOD was 0.97 +/- 0.1 (u/mL cells). A significant positive correlation was observed between intakes of green leafy vegetables, other vegetables and milk products with RBCMZn status (p < 0.05). But these were not correlated with plasma zinc (p > 0.2). Cereal and legume intakes were negatively correlated with RBCMZn (p < 0.05) but positively correlated with plasma zinc (p < 0.05) and not correlated with SOD (p > 0.2). Fruit and other vegetable intake were positively correlated with SOD (p < 0.05) alone. Logistic regression analyses revealed that RBCMZn was positively associated with intakes of beta-carotene, zinc and environmental conditions and negatively associated with family size (p < 0.05). Plasma zinc indicated positive association with zinc, thiamin and riboflavin intakes (p < 0.05) and SOD showed negative association with iron and family size. RBCMZn was a more sensitive indicator of long-term zinc status than plasma zinc and SOD. Prominent determinants of zinc status were intakes of beta-carotene and zinc along with environmental conditions and family size.

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.

Mining Genomes of Marine Cyanobacteria for Elements of Zinc Homeostasis

PubMed Central

Barnett, James P.; Millard, Andrew; Ksibe, Amira Z.; Scanlan, David J.; Schmid, Ralf; Blindauer, Claudia Andrea

2012-01-01

Zinc is a recognized essential element for the majority of organisms, and is indispensable for the correct function of hundreds of enzymes and thousands of regulatory proteins. In aquatic photoautotrophs including cyanobacteria, zinc is thought to be required for carbonic anhydrase and alkaline phosphatase, although there is evidence that at least some carbonic anhydrases can be cambialistic, i.e., are able to acquire in vivo and function with different metal cofactors such as Co2+ and Cd2+. Given the global importance of marine phytoplankton, zinc availability in the oceans is likely to have an impact on both carbon and phosphorus cycles. Zinc concentrations in seawater vary over several orders of magnitude, and in the open oceans adopt a nutrient-like profile. Most studies on zinc handling by cyanobacteria have focused on freshwater strains and zinc toxicity; much less information is available on marine strains and zinc limitation. Several systems for zinc homeostasis have been characterized in the freshwater species Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803, but little is known about zinc requirements or zinc handling by marine species. Comparative metallo-genomics has begun to explore not only the putative zinc proteome, but also specific protein families predicted to have an involvement in zinc homeostasis, including sensors for excess and limitation (SmtB and its homologs as well as Zur), uptake systems (ZnuABC), putative intracellular zinc chaperones (COG0523) and metallothioneins (BmtA), and efflux pumps (ZiaA and its homologs). PMID:22514551

Discovery of Human Zinc Deficiency: Its Impact on Human Health and Disease123

PubMed Central

Prasad, Ananda S.

2013-01-01

The essentiality of zinc in humans was established in 1963. During the past 50 y, tremendous advances in both clinical and basic sciences of zinc metabolism in humans have been observed. The major factor contributing to zinc deficiency is high phytate-containing cereal protein intake in the developing world, and nearly 2 billion subjects may be zinc deficient. Conditioned deficiency of zinc has been observed in patients with malabsorption syndrome, liver disease, chronic renal disease, sickle cell disease, and other chronic illnesses. Major clinical problems resulting from zinc deficiency in humans include growth retardation; cell-mediated immune dysfunction, and cognitive impairment. In the Middle East, zinc-deficient dwarfs did not live beyond the age of 25 y, and they died because of intercurrent infections. In 1963, we knew of only 3 enzymes that required zinc for their activities, but now we know of >300 enzymes and >1000 transcription factors that are known to require zinc for their activities. Zinc is a second messenger of immune cells, and intracellular free zinc in these cells participate in signaling events. Zinc has been very successfully used as a therapeutic modality for the management of acute diarrhea in children, Wilson’s disease, the common cold and for the prevention of blindness in patients with age-related dry type of macular degeneration and is very effective in decreasing the incidence of infection in the elderly. Zinc not only modulates cell-mediated immunity but is also an antioxidant and anti-inflammatory agent. PMID:23493534

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.

Zinc: health effects and research priorities for the 1990s.

PubMed Central

Walsh, C T; Sandstead, H H; Prasad, A S; Newberne, P M; Fraker, P J

1994-01-01

This review critically summarizes the literature on the spectrum of health effects of zinc status, ranging from symptoms of zinc deficiency to excess exposure. Studies on zinc intake are reviewed in relation to optimum requirements as a function of age and sex. Current knowledge on the biochemical properties of zinc which are critical to the essential role of this metal in biological systems is summarized. Dietary and physiological factors influencing the bioavailability and utilization of zinc are considered with special attention to interactions with iron and copper status. The effects of zinc deficiency and toxicity are reviewed with respect to specific organs, immunological and reproductive function, and genotoxicity and carcinogenicity. Finally, key questions are identified where research is needed, such as the risks to human health of altered environmental distribution of zinc, assessment of zinc status in humans, effects of zinc status in relation to other essential metals on immune function, reproduction, neurological function, and the cardiovascular system, and mechanistic studies to further elucidate the biological effects of zinc at the molecular level. PMID:7925188

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

DOE PAGES

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; ...

2014-12-15

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. Here we show that the zinc spark arises from a system of thousands ofmore » 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. We conclude that 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

Interaction Between Yeasts and Zinc

NASA Astrophysics Data System (ADS)

Nicola, Raffaele De; Walker, Graeme

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

Suppressive effect of zinc ion on iNOS expression induced by interferon-gamma or tumor necrosis factor-alpha in murine keratinocytes.

PubMed

Yamaoka, J; Kume, T; Akaike, A; Miyachi, Y

2000-05-01

Zinc, an essential metal, is a critical component of zinc binding proteins such as zinc fingers, zinc enzymes and metallothioneins. Recently, evidence for its anti-inflammatory property in skin has been accumulating, as shown in the treatment of acne, alopecia and zinc deficiency. In cutaneous inflammations, a large amount of nitric oxide (NO) is produced through induction of inducible nitric oxide synthase (iNOS) under the influence of proinflammatory cytokines, resulting in tissue damages in skin, as clarified in other organs. Therefore, we asked if the effect of zinc on NO production and/or on iNOS expression in keratinocytes may explain the anti-inflammatory property of zinc in skin. Accordingly, we sought to determine in this study whether zinc ion may have effect on IFN-gamma or TNF-alpha induced NO production and iNOS expression in cultured murine keratinocytes. Ten microM of zinc ion remarkably suppressed cytokine-induced NO production in keratinocytes. Furthermore, zinc ion also suppressed cytokine-induced iNOS expression in the protein level as well as in the messenger RNA level. These results suggest the possibility that the suppressive effect of zinc ion on cytokine-induced NO production in keratinocytes may be in part implicated in the anti-inflammatory property of zinc in some of skin disorders.

[Effect of cultivation in zinc media on the growth of and the degree of zinc in organic form in transgenic metallothionein mushroom].

PubMed

Sheng, Ji-Ping; Shen, Lin; Ru, Bing-Gen

2009-03-01

Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich and metal-binding functional proteins. Transgenic MT mushroom can be used as functional food additives, but its zinc-enriching ability has not been studied systemically until now. The zinc contents in mycelia of transgenic MT mushroom (Pleurotus ostreatus) and wild type mushroom mycelia cultivated in different zinc concentration media were analyzed by ICP-OES. The growth status, zinc-enriching ability and degree of zinc in organic form (DZOF) were also analyzed. Results showed that MT mushroom mycelia grew rapidly, but the growth was inhibited when the zinc content in solid media was higher than 1.6 mmol x L(-1). MT mushroom mycelia could enrich more zinc than that of wild type, and the zinc content in MT mushroom mycelia could be 2.56-27.49 mg x kg(-1) when it was cultivated in a liquid media with 0.6-1.2 mmol x L(-1) zinc. DZOF of MT mushroom mycelia in a liquid media with 0.6 mmol x L(-1) zinc at 7 d was significantly higher (88.7%) than that in the wild type (82.1%, alpha = 0.05), but there was no significant difference in DZOF when the MT mushroom mycelia was cultivated in a liquid media with different zinc content at 7 d.

A marriage of convenience; a simple food chain comprised of Lemna minor (L.) and Gammarus pulex (L.) to study the dietary transfer of zinc.

PubMed

Lahive, E; O'Halloran, J; Jansen, M A K

2015-01-01

Macrophytes contribute significantly to the cycling of metals in aquatic systems, through accumulation during growth and release during herbivory or decomposition. Accumulation of high levels of metals has been extensively documented in Lemnaceae (duckweeds). However, the degree of trophic transfer of metals from Lemnaceae to secondary consumers remains poorly understood. This study demonstrates that zinc accumulated in Lemna minor is bioavailable to the herbivore consumer Gammarus pulex. Overall, the higher the zinc content of L. minor, the more zinc accumulated in G. pulex. Accumulation in G. pulex was such that mortality occurred when they were fed high zinc-containing L. minor. Yet, the percentage of consumed zinc retained by G. pulex actually decreased with higher zinc concentrations in L. minor. We hypothesise that this decrease reflects internal zinc metabolism, including a shift from soluble to covalently bound zinc in high zinc-containing L. minor. Consistently, relatively more zinc is lost through depuration when G. pulex is fed L. minor with high zinc content. The developed Lemna-Gammarus system is simple, easily manipulated, and sensitive enough for changes in plant zinc metabolism to be reflected in metal accumulation by the herbivore, and therefore suitable to study ecologically relevant metal cycling in aquatic ecosystems. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Zinc halogen battery electrolyte composition with lead additive

DOEpatents

Henriksen, Gary L.

1981-01-01

This disclosure relates to a zinc halogen battery electrolyte composition containing an additive providing improved zinc-on-zinc recyclability. The improved electrolyte composition involves the use of a lead additive to inhibit undesirable irregular plating and reduce nodular or dendritic growth on the electrode surface. The lead-containing electrolyte composition of the present invention appears to influence not only the morphology of the base plate zinc, but also the morphology of the zinc-on-zinc replate. In addition, such lead-containing electrolyte compositions appear to reduce hydrogen formation.

Alterations in protein kinase C activity and processing during zinc-deficiency-induced cell death.

PubMed

Chou, Susan S; Clegg, Michael S; Momma, Tony Y; Niles, Brad J; Duffy, Jodie Y; Daston, George P; Keen, Carl L

2004-10-01

Protein kinases C (PKCs) are a family of serine/threonine kinases that are critical for signal transduction pathways involved in growth, differentiation and cell death. All PKC isoforms have four conserved domains, C1-C4. The C1 domain contains cysteine-rich finger-like motifs, which bind two zinc atoms. The zinc-finger motifs modulate diacylglycerol binding; thus, intracellular zinc concentrations could influence the activity and localization of PKC family members. 3T3 cells were cultured in zinc-deficient or zinc-supplemented medium for up to 32 h. Cells cultured in zinc-deficient medium had decreased zinc content, lowered cytosolic classical PKC activity, increased caspase-3 processing and activity, and reduced cell number. Zinc-deficient cytosols had decreased activity and expression levels of PKC-alpha, whereas PKC-alpha phosphorylation was not altered. Inhibition of PKC-alpha with Gö6976 had no effect on cell number in the zinc-deficient group. Proteolysis of the novel PKC family member, PKC-delta, to its 40-kDa catalytic fragment occurred in cells cultured in the zinc-deficient medium. Occurrence of the PKC-delta fragment in mitochondria was co-incident with caspase-3 activation. Addition of the PKC-delta inhibitor, rottlerin, or zinc to deficient medium reduced or eliminated proteolysis of PKC-delta, activated caspase-3 and restored cell number. Inhibition of caspase-3 processing by Z-DQMD-FMK (Z-Asp-Gln-Met-Asp-fluoromethylketone) did not restore cell number in the zinc-deficient group, but resulted in processing of full-length PKC-delta to a 56-kDa fragment. These results support the concept that intracellular zinc concentrations influence PKC activity and processing, and that zinc-deficiency-induced apoptosis occurs in part through PKC-dependent pathways.

Dietary catechins and procyanidins modulate zinc homeostasis in human HepG2 cells.

PubMed

Quesada, Isabel M; Bustos, Mario; Blay, Mayte; Pujadas, Gerard; Ardèvol, Anna; Salvadó, M Josepa; Bladé, Cinta; Arola, Lluís; Fernández-Larrea, Juan

2011-02-01

Catechins and their polymers procyanidins are health-promoting flavonoids found in edible vegetables and fruits. They act as antioxidants by scavenging reactive oxygen species and by chelating the redox-active metals iron and copper. They also behave as signaling molecules, modulating multiple cell signalling pathways and gene expression, including that of antioxidant enzymes. This study aimed at determining whether catechins and procyanidins interact with the redox-inactive metal zinc and at assessing their effect on cellular zinc homeostasis. We found that a grape-seed procyanidin extract (GSPE) and the green tea flavonoid (-)-epigallocatechin-3-gallate (EGCG) bind zinc cations in solution with higher affinity than the zinc-specific chelator Zinquin, and dose-dependently prevent zinc-induced toxicity in the human hepatocarcinoma cell line HepG2, evaluated by the lactate dehydrogenase test. GSPE and EGCG hinder intracellular accumulation of total zinc, measured by atomic flame absorption spectrometry, concomitantly increasing the level of cytoplasmic labile zinc detectable by Zinquin fluorescence. Concurrently, GSPE and EGCG inhibit the expression, evaluated at the mRNA level by quantitative reverse transcriptase-polymerase chain reaction, of zinc-binding metallothioneins and of plasma membrane zinc exporter ZnT1 (SLC30A1), while enhancing the expression of cellular zinc importers ZIP1 (SLC39A1) and ZIP4 (SLC39A4). GSPE and EGCG also produce all these effects when HepG2 cells are stimulated to import zinc by treatment with supplemental zinc or the proinflammatory cytokine interleukin-6. We suggest that extracellular complexation of zinc cations and the elevation of cytoplasmic labile zinc may be relevant mechanisms underlying the modulation of diverse cell signaling and metabolic pathways by catechins and procyanidins. Copyright © 2011 Elsevier Inc. All rights reserved.

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.

Mechanisms of zinc binding to the solute-binding protein AztC and transfer from the metallochaperone AztD.

PubMed

Neupane, Durga P; Avalos, Dante; Fullam, Stephanie; Roychowdhury, Hridindu; Yukl, Erik T

2017-10-20

Bacteria can acquire the essential metal zinc from extremely zinc-limited environments by using ATP-binding cassette (ABC) transporters. These transporters are critical virulence factors, relying on specific and high-affinity binding of zinc by a periplasmic solute-binding protein (SBP). As such, the mechanisms of zinc binding and release among bacterial SBPs are of considerable interest as antibacterial drug targets. Zinc SBPs are characterized by a flexible loop near the high-affinity zinc-binding site. The function of this structure is not always clear, and its flexibility has thus far prevented structural characterization by X-ray crystallography. Here, we present intact structures for the zinc-specific SBP AztC from the bacterium Paracoccus denitrificans in the zinc-bound and apo-states. A comparison of these structures revealed that zinc loss prompts significant structural rearrangements, mediated by the formation of a sodium-binding site in the apo-structure. We further show that the AztC flexible loop has no impact on zinc-binding affinity, stoichiometry, or protein structure, yet is essential for zinc transfer from the metallochaperone AztD. We also found that 3 His residues in the loop appear to temporarily coordinate zinc and then convey it to the high-affinity binding site. Thus, mutation of any of these residues to Ala abrogated zinc transfer from AztD. Our structural and mechanistic findings conclusively identify a role for the AztC flexible loop in zinc acquisition from the metallochaperone AztD, yielding critical insights into metal binding by AztC from both solution and AztD. These proteins are highly conserved in human pathogens, making this work potentially useful for the development of novel antibiotics. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Zinc deficiency mediates alcohol-induced apoptotic cell death in the liver of rats through activating ER and mitochondrial cell death pathways

PubMed Central

Sun, Qian; Zhong, Wei; Zhang, Wenliang; Li, Qiong; Sun, Xiuhua; Tan, Xiaobing; Sun, Xinguo; Dong, Daoyin

2015-01-01

Hepatic zinc deficiency has been well documented in alcoholic patients, but the mechanisms by which zinc deficiency mediates cell death have not been well defined. The objectives of this study were to determine whether alcohol perturbs subcellular zinc homeostasis and how organelle zinc depletion may link with cell death pathways. Wistar rats were pair-fed with the Lieber-DeCarli control or ethanol diet for 5 mo. Chronic alcohol exposure significantly reduced zinc level in isolated hepatic endoplasmic reticulum (ER) and mitochondria. Among the detected zinc transporters, ER Zrt/Irt-like protein (ZIP)13 and mitochondrial ZIP8, which transport zinc from ER and mitochondria to cytosol, were significantly increased. Mitochondrial zinc transporter (ZnT) 4, which transports zinc from cytosol to mitochondria, was also increased. ER phosphorylated eukaryotic initiation factor 2α, activating transcription factor 4, and C/EBP homologous protein were significantly upregulated, and mitochondrial cytochrome c release and Bax insertion were detected in association with caspase-3 activation and apoptotic cell death. To define the role of zinc deficiency in ER and mitochondrial stress, H4IIEC3 cells were treated with 3 μM N,N,N′,N′-tetrakis (2-pyridylmethyl) ethylenediamine for 6 h with or without supplementation with zinc or N-acetylcysteine (NAC). The results demonstrated that zinc deprivation induced caspase-3 activation and apoptosis in association with ER and mitochondria dysfunction, which were inhibited by zinc as low as 10 μM but not by 2 mM NAC. These results suggest that chronic ethanol exposure induced in ER and mitochondrial zinc deficiency might activate intrinsic cell death signaling pathway, which could not be effectively rescued by antioxidant treatment. PMID:25767260

The beneficial effects of zinc on diabetes-induced kidney damage in murine rodent model of type 1 diabetes mellitus.

PubMed

Yang, Fan; Li, Bing; Dong, Xiaoming; Cui, Wenpeng; Luo, Ping

2017-07-01

Diabetes mellitus is a chronic multi-factorial metabolic disorder resulting from impaired glucose homeostasis. Zinc is a key co-factor for the correct functioning of anti-oxidant enzymes. Zinc deficiency therefore, impairs their synthesis, leading to increased oxidative stress within cells. Zinc deficiency occurs commonly in diabetic patients. The aim of this study is to investigate the effects of varying concentrations of zinc on diabetic nephropathy (DN) and the underlying mechanisms involved. FVB male mice aged 8 weeks were injected intraperitoneally with multiple low-dose streptozotocin at a concentration of 50mg/kg body weight daily for 5 days. Diabetic and age-matched control mice were treated with special diets supplemented with zinc at varying concentrations (0.85mg/kg, 30mg/kg, 150mg/kg) for 3 months. The mice were fed with zinc diets to mimic the process of oral administration of zinc in human. Zinc deficiency to some extent aggravated the damage of diabetic kidney. Feeding with normal (30mg/kg zinc/kg diet) and especially high (150mg/kg zinc/kg diet) concentration zinc could protect the kidney against diabetes-induced damage. The beneficial effects of zinc on DN are achieved most likely due to the upregulation of Nrf2 and its downstream factors NQO1, SOD1, SOD2. Zinc upregulated the expression of Akt phosphorylation and GSK-3β phosphorylation, resulting in a reduction in Fyn nuclear translocation and export of Nrf2 to the cytosol. Thus, regular monitoring and maintaining of adequate levels of zinc are recommended in diabetic individuals in order to delay the development of DN. Copyright © 2017 Elsevier GmbH. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Luque, P. A.; Gómez-Gutiérrez, Claudia M.; Lastra, G.; Carrillo-Castillo, A.; Quevedo-López, M. A.; Olivas, A.

2014-11-01

Zinc sulfide (ZnS) thin films have been grown by chemical bath deposition (CBD) using different zinc sources on a silicon nitride (Si3N4) substrate in an alkaline solution. The zinc precursors used were zinc acetate, zinc nitrate, and zinc sulfate. The structural and optical characteristics of the ZnS thin films obtained were analyzed. The morphology of the surface showed that the films were compact and uniform, with some pinholes in the surface depending on the zinc source. The most homogeneous and compact surfaces were those obtained using zinc nitrate as the zinc source with a root-mean-square (RMS) value of 3 nm. The transmission spectra indicated average transmittance of 80% to 85% in the spectral range from 300 nm to 800 nm, and the optical bandgap calculated for the films was around 3.71 eV to 3.74 eV.

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.

Structural and Functional Studies of the Protamine 2-Zinc Complex from Syrian Gold Hamster (Mesocricetus Auratus) Spermatids and Sperm

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

Dolan, Cheryl E.

The research described in this dissertation consists of four major areas: (1) sequence analysis of protamine 2 from Muroid rodents to identify potential zinc-binding domain(s) of protamine 2; (2) structural studies of the protamine 2-zinc complex from Syrian Gold hamster sperm and spermatids to elucidate the role of zinc during spermiogenesis; (3) structural studies of an unique protamine 2-zinc complex from chinchilla sperm; and (4) Nuclear Magnetic Resonance (NMR) studies of soluble complexes of hairpin oligonucleotides with synthetic arginine-rich peptides or protamine 1 isolated from bull sperm. First, zinc was quantitated in spermatids and sperm by Proton-Induced X-ray Emission (PIXE)more » to determine whether zinc is present in the early stages of spermiogenesis. The PIXE results revealed the zinc content varies proportionately with the amount of protamine 2 in both spermatid and sperm nuclei. An exception was chinchilla sperm containing twice the amount of protamine 2 than zinc. Further analyses by PIXE and X-ray Absorption Spectroscopy (XAS) of zinc bound to protamines isolated from hamster sperm confirmed the majority of the zinc is bound to protamine and identified the zinc ligands of protamine 2 in hamster spermatids and sperm in vivo. These studies established that zinc is bound to the protamine 2 precursor in hamster spermatids and the coordination of zinc by protamine 2 changes during spermiogenesis. Finally, the sequence analysis combined with the XAS results suggest that the zinc-binding domain in protamine 2 resides in the amino-terminus. Similar analyses of chinchilla sperm by XAS were performed to clarify the unusual PIXE results and revealed that chinchilla has an atypical protamine 2-zinc structure. Two protamine 2 molecules coordinate one zinc atom, forming homodimers that facilitate the binding of protamine 2 to DNA and provide an organizational scheme that would accommodate the observed species-specific protamine stoichiometry in mammalian sperm. Based on these results, we propose the binding of zinc to protamine 2 molecules stabilizes a dimerization domain in other mammalian sperm. Future experiments will use the knowledge we gained of the interactions between protamine 1 and DNA from the NMR studies to obtain structural data for the DNA-protamine 2-zinc complex.« less

Selective electrodiffusion of zinc ions in a Zrt-, Irt-like protein, ZIPB

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

Lin, W.; Fu, D.; Chai, J.

2010-12-10

All living cells need zinc ions to support cell growth. Zrt-, Irt-like proteins (ZIPs) represent a major route for entry of zinc ions into cells, but how ZIPs promote zinc uptake has been unclear. Here we report the molecular characterization of ZIPB from Bordetella bronchiseptica, the first ZIP homolog to be purified and functionally reconstituted into proteoliposomes. Zinc flux through ZIPB was found to be nonsaturable and electrogenic, yielding membrane potentials as predicted by the Nernst equation. Conversely, membrane potentials drove zinc fluxes with a linear voltage-flux relationship. Direct measurements of metal uptake by inductively coupled plasma mass spectroscopy demonstratedmore » that ZIPB is selective for two group 12 transition metal ions, Zn{sup 2+} and Cd{sup 2+}, whereas rejecting transition metal ions in groups 7 through 11. Our results provide the molecular basis for cellular zinc acquisition by a zinc-selective channel that exploits in vivo zinc concentration gradients to move zinc ions into the cytoplasm.« less

Zinc release contributes to hypoglycemia-induced neuronal death.

PubMed

Suh, Sang Won; Garnier, Philippe; Aoyama, Koji; Chen, Yongmei; Swanson, Raymond A

2004-08-01

Neurons exposed to zinc exhibit activation of poly(ADP-ribose) polymerase-1 (PARP-1), an enzyme that normally participates in DNA repair but promotes cell death when extensively activated. Endogenous, vesicular zinc in brain is released to the extracellular space under conditions causing neuronal depolarization. Here, we used a rat model of insulin-induced hypoglycemia to assess the role of zinc release in PARP-1 activation and neuronal death after severe hypoglycemia. Zinc staining with N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide (TSQ) showed depletion of presynaptic vesicular zinc from hippocampal mossy fiber terminals and accumulation of weakly bound zinc in hippocampal CA1 cell bodies after severe hypoglycemia. Intracerebroventricular injection of the zinc chelator calcium ethylene-diamine tetraacetic acid (CaEDTA) blocked the zinc accumulation and significantly reduced hypoglycemia-induced neuronal death. CaEDTA also attenuated the accumulation of poly(ADP-ribose), the enzymatic product of PARP-1, in hippocampal neurons. These results suggest that zinc translocation is an intermediary step linking hypoglycemia to PARP-1 activation and neuronal death.

Zinc and Chlamydia trachomatis

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

Sugarman, B.; Epps, L.R.

1985-07-01

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

Zinc is an Antioxidant and Anti-Inflammatory Agent: Its Role in Human Health

PubMed Central

Prasad, Ananda S.

2014-01-01

Zinc supplementation trials in the elderly showed that the incidence of infections was decreased by approximately 66% in the zinc group. Zinc supplementation also decreased oxidative stress biomarkers and decreased inflammatory cytokines in the elderly. In our studies in the experimental model of zinc deficiency in humans, we showed that zinc deficiency per se increased the generation of IL-1β and its mRNA in human mononuclear cells following LPS stimulation. Zinc supplementation upregulated A20, a zinc transcription factor, which inhibited the activation of NF-κB, resulting in decreased generation of inflammatory cytokines. Oxidative stress and chronic inflammation are important contributing factors for several chronic diseases attributed to aging, such as atherosclerosis and related cardiac disorders, cancer, neurodegeneration, immunologic disorders and the aging process itself. Zinc is very effective in decreasing reactive oxygen species (ROS). In this review, the mechanism of zinc actions on oxidative stress and generation of inflammatory cytokines and its impact on health in humans will be presented. PMID:25988117

Effects of Zinc on Particulate Methane Monooxygenase Activity and Structure*

PubMed Central

Sirajuddin, Sarah; Barupala, Dulmini; Helling, Stefan; Marcus, Katrin; Stemmler, Timothy L.; Rosenzweig, Amy C.

2014-01-01

Particulate methane monooxygenase (pMMO) is a membrane-bound metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria. Zinc is a known inhibitor of pMMO, but the details of zinc binding and the mechanism of inhibition are not understood. Metal binding and activity assays on membrane-bound pMMO from Methylococcus capsulatus (Bath) reveal that zinc inhibits pMMO at two sites that are distinct from the copper active site. The 2.6 Å resolution crystal structure of Methylocystis species strain Rockwell pMMO reveals two previously undetected bound lipids, and metal soaking experiments identify likely locations for the two zinc inhibition sites. The first is the crystallographic zinc site in the pmoC subunit, and zinc binding here leads to the ordering of 10 previously unobserved residues. A second zinc site is present on the cytoplasmic side of the pmoC subunit. Parallels between these results and zinc inhibition studies of several respiratory complexes suggest that zinc might inhibit proton transfer in pMMO. PMID:24942740

Mineral resource of the month: zinc

USGS Publications Warehouse

Tolcin, Amy C.

2009-01-01

The article provides information on zinc, the fourth most-widely consumed metal. It traces the first use of zinc with the Romans' production of brass. It describes the presence of zinc in Earth's crust and the importance of sphalerite as a source of zinc and other some minor metal production. The production and consumption of zinc as well as the commercial and industrial uses of this metal are also discussed.

Effect of zinc gluconate, sage oil on inflammatory patterns and hyperglycemia in zinc deficient diabetic rats.

PubMed

Elseweidy, Mohamed M; Ali, Abdel-Moniem A; Elabidine, Nabila Zein; Mursey, Nada M

2017-11-01

The relationship between zinc homeostasis and pancreatic function had been established. In this study we aimed firstly to configure the inflammatory pattern and hyperglycemia in zinc deficient diabetic rats. Secondly to illustrate the effect of two selected agents namely Zinc gluconate and sage oil (Salvia Officinalis, family Lamiaceae). Rats were fed on Zinc deficient diet, deionized water for 28days along with Zinc level check up at intervals to achieve zinc deficient state then rats were rendered diabetic through receiving one dose of alloxan monohydrate (120mg/kg) body weight, classified later into 5 subgroups. Treatment with sage oil (0.042mg/kg IP) and Zinc gluconate orally (150mg/kg) body weight daily for 8 weeks significantly reduced serum glucose, C-reactive protein (CRP), Tumor necrosis factor alpha (TNF- α), interleukins-6 1 β, inflammatory8 (IFN ȣ), pancreatic 1L1-β along with an increase in serum Zinc and pancreatic Zinc transporter 8 (ZNT8). Histopathological results of pancreatic tissues showed a good correlation with the biochemical findings. Both sage oil and zinc gluconate induced an improvement in the glycemic and inflammatory states. This may be of value like the therapeutic agent for diabetes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Comparative studies on acid leaching of zinc waste materials

NASA Astrophysics Data System (ADS)

Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

2017-11-01

Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

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

Zinc-rich oysters as well as zinc-yeast- and astaxanthin-enriched food improved sleep efficiency and sleep onset in a randomized controlled trial of healthy individuals.

PubMed

Saito, Hitomi; Cherasse, Yoan; Suzuki, Rina; Mitarai, Makoto; Ueda, Fumitaka; Urade, Yoshihiro

2017-05-01

Zinc is an essential mineral that plays an important role in the body. We previously reported that orally feeding zinc-enriched yeast to mice induces nonrapid-eye-movement sleep. In addition, astaxanthin, an antioxidant abundant in seafood such as salmon and krill, is able to chelate minerals and may promote zinc absorption, which in return may also improve sleep. The purpose of our study was to examine the effect of zinc-rich and astaxanthin-containing food on sleep in humans. We conducted a randomized, double-blinded, placebo-controlled parallel group trial of 120 healthy subjects and recorded their night activity by actigraphy for 12 weeks. These subjects were divided into four groups: placebo, zinc-rich food, zinc-, and astaxanthin-rich food, and placebo supplemented with zinc-enriched yeast and astaxanthin oil. Compared with the placebo group, the zinc-rich food group efficiently decreased the time necessary to fall asleep and improved sleep efficiency, whereas the group that ingested zinc-enriched yeast and astaxanthin oil significantly improved the sleep onset latency. Actigraphic sleep monitoring demonstrated that eating zinc-rich food improved sleep onset latency as well as improved the sleep efficiency in healthy individuals. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

PubMed

Zhang, M Q; Guo, Y; Powell, C A; Doud, M S; Yang, C Y; Zhou, H; Duan, Y P

2016-06-01

Huanglongbing (HLB)-affected citrus often display zinc deficiency symptoms. In this study, supplemental zinc was applied to citrus to determine its effect on Candidatus Liberibacter asiaticus (Las) titre, HLB symptoms, and leaf microbiome. HLB-affected citrus were treated with various amounts of zinc. The treatments promoted Las growth and affected microbiomes in citrus leaves. Phylochip(™) -based results indicated that 5475 of over 50 000 known Operational Taxonomic Units (OTUs) in 52 phyla were detected in the midribs of HLB-affected citrus, of which Proteobacteria was the most abundant, followed by Firmicutes and Actinobacteria. In comparison, the microbiomes of zinc-treated diseased plants had overall more OTUs with higher amounts of Proteobacteria, but decreased percentages of Firmicutes and Actinobacteria. In addition, more OTUs of siderophore-producing bacteria were present. Only zinc-sensitive Staphylococcaceae had higher OTU's in the diseased plants without zinc treatments. Although HLB-affected citrus appear zinc deficient, zinc amendments increased the pathogen levels and shifted the microbiome. HLB is currently the most devastating disease of citrus worldwide. Zinc is often applied to HLB-affected citrus due to zinc deficiency symptoms. This study provided new insights into the potential effects of zinc on HLB and the microbial ecology of citrus. © 2016 The Society for Applied Microbiology.

Zinc induces long-term upregulation of T-type calcium current in hippocampal neurons in vivo.

PubMed

Ekstein, Dana; Benninger, Felix; Daninos, Moshe; Pitsch, Julika; van Loo, Karen M J; Becker, Albert J; Yaari, Yoel

2012-11-15

Extracellular zinc can induce numerous acute and persistent physiological and toxic effects in neurons by acting at their plasma membrane or intracellularly following permeation or uptake into them. Zinc acutely and reversibly blocks T-type voltage-gated calcium current (I(CaT)), but the long-term effect of zinc on this current has not been studied. Because chemically induced status epilepticus (SE) results in the release of zinc into the extracellular space, as well as in a long-lasting increase in I(CaT) in CA1 pyramidal cells, we hypothesized that zinc may play a causative role in I(CaT) upregulation. We tested this hypothesis by monitoring for 18 days the effects of zinc and ibotenic acid (a neurotoxic agent serving as control for zinc), injected into the right lateral ventricle, on I(CaT) in rat CA1 pyramidal cells. Both zinc and ibotenic acid caused marked hippocampal lesions on the side of injection, but only minor damage to contralateral hippocampi. Zinc, but not ibotenic acid, caused upregulation of a nickel-sensitive I(CaT) in a subset of contralateral CA1 pyramidal cells, appearing 2 days after injection and lasting for about 2 weeks thereafter. In contrast, acute application of zinc to CA1 pyramidal cells promptly blocked I(CaT). These data indicate that extracellular zinc has a dual effect on I(CaT), blocking it acutely while causing its long-term upregulation. Through the latter effect, zinc may regulate the intrinsic excitability of principal neurons, particularly in pathological conditions associated with enhanced release of zinc, such as SE.

Vacuolar zinc transporter Zrc1 is required for detoxification of excess intracellular zinc in the human fungal pathogen Cryptococcus neoformans.

PubMed

Cho, Minsu; Hu, Guanggan; Caza, Mélissa; Horianopoulos, Linda C; Kronstad, James W; Jung, Won Hee

2018-01-01

Zinc is an important transition metal in all living organisms and is required for numerous biological processes. However, excess zinc can also be toxic to cells and cause cellular stress. In the model fungus Saccharomyces cerevisiae, a vacuolar zinc transporter, Zrc1, plays important roles in the storage and detoxification of excess intracellular zinc to protect the cell. In this study, we identified an ortholog of the S. cerevisiae ZRC1 gene in the human fungal pathogen Cryptococcus neoformans. Zrc1 was localized in the vacuolar membrane in C. neoformans, and a mutant lacking ZRC1 showed significant growth defects under high-zinc conditions. These results suggested a role for Zrc1 in zinc detoxification. However, contrary to our expectation, the expression of Zrc1 was induced in cells grown in zinc-limited conditions and decreased upon the addition of zinc. These expression patterns were similar to those of Zip1, the high-affinity zinc transporter in the plasma membrane of C. neoformans. Furthermore, we used the zrc1 mutant in a murine model of cryptococcosis to examine whether a mammalian host could inhibit the survival of C. neoformans using zinc toxicity. We found that the mutant showed no difference in virulence compared with the wildtype strain. This result suggests that Zrc1-mediated zinc detoxification is not required for the virulence of C. neoformans, and imply that zinc toxicity may not be an important aspect of the host immune response to the fungus.

Characterisation of zinc delivery from a nipple shield delivery system using a breastfeeding simulation apparatus

PubMed Central

Bruggraber, Sylvaine F. A.; Gerrard, Stephen E.; Kendall, Richard A.; Tuleu, Catherine; Slater, Nigel K. H.

2017-01-01

Zinc delivery from a nipple shield delivery system (NSDS), a novel platform for administering medicines to infants during breastfeeding, was characterised using a breastfeeding simulation apparatus. In this study, human milk at flow rates and pressures physiologically representative of breastfeeding passed through the NSDS loaded with zinc-containing rapidly disintegrating tablets, resulting in release of zinc into the milk. Inductively coupled plasma optical emission spectrometry was used to detect the zinc released, using a method that does not require prior digestion of the samples and that could be applied in other zinc analysis studies in breast milk. Four different types of zinc-containing tablets with equal zinc load but varying excipient compositions were tested in the NSDS in vitro. Zinc release measured over 20 minutes ranged from 32–51% of the loaded dose. Total zinc release for sets tablets of the same composition but differing hardness were not significantly different from one another with P = 0.3598 and P = 0.1270 for two tested pairs using unpaired t tests with Welch’s correction. By the same test total zinc release from two sets of tablets having similar hardness but differing composition were also not significantly significant with P = 0.2634. Future zinc tablet composition and formulation optimisation could lead to zinc supplements and therapeutics with faster drug release, which could be administered with the NSDS during breastfeeding. The use of the NSDS to deliver zinc could then lead to treatment and prevention of some of the leading causes of child mortality, including diarrheal disease and pneumonia. PMID:28158283

Characterisation of zinc delivery from a nipple shield delivery system using a breastfeeding simulation apparatus.

PubMed

Scheuerle, Rebekah L; Bruggraber, Sylvaine F A; Gerrard, Stephen E; Kendall, Richard A; Tuleu, Catherine; Slater, Nigel K H

2017-01-01

Zinc delivery from a nipple shield delivery system (NSDS), a novel platform for administering medicines to infants during breastfeeding, was characterised using a breastfeeding simulation apparatus. In this study, human milk at flow rates and pressures physiologically representative of breastfeeding passed through the NSDS loaded with zinc-containing rapidly disintegrating tablets, resulting in release of zinc into the milk. Inductively coupled plasma optical emission spectrometry was used to detect the zinc released, using a method that does not require prior digestion of the samples and that could be applied in other zinc analysis studies in breast milk. Four different types of zinc-containing tablets with equal zinc load but varying excipient compositions were tested in the NSDS in vitro. Zinc release measured over 20 minutes ranged from 32-51% of the loaded dose. Total zinc release for sets tablets of the same composition but differing hardness were not significantly different from one another with P = 0.3598 and P = 0.1270 for two tested pairs using unpaired t tests with Welch's correction. By the same test total zinc release from two sets of tablets having similar hardness but differing composition were also not significantly significant with P = 0.2634. Future zinc tablet composition and formulation optimisation could lead to zinc supplements and therapeutics with faster drug release, which could be administered with the NSDS during breastfeeding. The use of the NSDS to deliver zinc could then lead to treatment and prevention of some of the leading causes of child mortality, including diarrheal disease and pneumonia.

Comparison of complementary feeding strategies to meet zinc requirements of older breastfed infants1234

PubMed Central

Krebs, Nancy F; Westcott, Jamie E; Culbertson, Diana L; Sian, Lei; Miller, Leland V; Hambidge, K Michael

2012-01-01

Background: The low zinc intake from human milk at ∼6 mo of age predicts the dependence on complementary foods (CF) to meet the zinc requirements of older breastfed-only infants. Objective: The objective of this study was to compare major variables of zinc homeostasis and zinc status in 9-mo-old breastfed infants who were randomly assigned to different complementary food regimens. Design: Forty-five exclusively breastfed 5-mo-old infants were randomly assigned to receive commercially available pureed meats, iron-and-zinc–fortified infant cereal (IZFC), or whole-grain, iron-only–fortified infant cereal (IFC) as the first and primary CF until completion of zinc metabolic studies between 9 and 10 mo of age. A zinc stable-isotope methodology was used to measure the fractional absorption of zinc (FAZ) in human milk and CF by dual-isotope ratios in urine. Calculated variables included the dietary intake from duplicate diets and 4-d test weighing, the total absorbed zinc (TAZ) from FAZ × diet zinc, and the exchangeable zinc pool size (EZP) from isotope enrichment in urine. Results: Mean daily zinc intakes were significantly greater for the meat and IZFC groups than for the IFC group (P < 0.001); only intakes in meat and IZFC groups met estimated average requirements. Mean (±SEM) TAZ amounts were 0.80 ± 0.08, 0.71 ± 0.09, and 0.52 ± 0.05 mg/d for the meat, IZFC, and IFC groups, respectively (P = 0.027). Zinc from human milk contributed <25% of TAZ for all groups. The EZP correlated with both zinc intake (r = 0.43, P < 0.01) and TAZ (r = 0.54, P < 0.001). Conclusion: Zinc requirements for older breastfed-only infants are unlikely to be met without the regular consumption of either meats or zinc-fortified foods. PMID:22648720

Total Zinc Intake May Modify the Glucose-Raising Effect of a Zinc Transporter (SLC30A8) Variant

PubMed Central

Kanoni, Stavroula; Nettleton, Jennifer A.; Hivert, Marie-France; Ye, Zheng; van Rooij, Frank J.A.; Shungin, Dmitry; Sonestedt, Emily; Ngwa, Julius S.; Wojczynski, Mary K.; Lemaitre, Rozenn N.; Gustafsson, Stefan; Anderson, Jennifer S.; Tanaka, Toshiko; Hindy, George; Saylor, Georgia; Renstrom, Frida; Bennett, Amanda J.; van Duijn, Cornelia M.; Florez, Jose C.; Fox, Caroline S.; Hofman, Albert; Hoogeveen, Ron C.; Houston, Denise K.; Hu, Frank B.; Jacques, Paul F.; Johansson, Ingegerd; Lind, Lars; Liu, Yongmei; McKeown, Nicola; Ordovas, Jose; Pankow, James S.; Sijbrands, Eric J.G.; Syvänen, Ann-Christine; Uitterlinden, André G.; Yannakoulia, Mary; Zillikens, M. Carola; Wareham, Nick J.; Prokopenko, Inga; Bandinelli, Stefania; Forouhi, Nita G.; Cupples, L. Adrienne; Loos, Ruth J.; Hallmans, Goran; Dupuis, Josée; Langenberg, Claudia; Ferrucci, Luigi; Kritchevsky, Stephen B.; McCarthy, Mark I.; Ingelsson, Erik; Borecki, Ingrid B.; Witteman, Jacqueline C.M.; Orho-Melander, Marju; Siscovick, David S.; Meigs, James B.; Franks, Paul W.; Dedoussis, George V.

2011-01-01

OBJECTIVE Many genetic variants have been associated with glucose homeostasis and type 2 diabetes in genome-wide association studies. Zinc is an essential micronutrient that is important for β-cell function and glucose homeostasis. We tested the hypothesis that zinc intake could influence the glucose-raising effect of specific variants. RESEARCH DESIGN AND METHODS We conducted a 14-cohort meta-analysis to assess the interaction of 20 genetic variants known to be related to glycemic traits and zinc metabolism with dietary zinc intake (food sources) and a 5-cohort meta-analysis to assess the interaction with total zinc intake (food sources and supplements) on fasting glucose levels among individuals of European ancestry without diabetes. RESULTS We observed a significant association of total zinc intake with lower fasting glucose levels (β-coefficient ± SE per 1 mg/day of zinc intake: −0.0012 ± 0.0003 mmol/L, summary P value = 0.0003), while the association of dietary zinc intake was not significant. We identified a nominally significant interaction between total zinc intake and the SLC30A8 rs11558471 variant on fasting glucose levels (β-coefficient ± SE per A allele for 1 mg/day of greater total zinc intake: −0.0017 ± 0.0006 mmol/L, summary interaction P value = 0.005); this result suggests a stronger inverse association between total zinc intake and fasting glucose in individuals carrying the glucose-raising A allele compared with individuals who do not carry it. None of the other interaction tests were statistically significant. CONCLUSIONS Our results suggest that higher total zinc intake may attenuate the glucose-raising effect of the rs11558471 SLC30A8 (zinc transporter) variant. Our findings also support evidence for the association of higher total zinc intake with lower fasting glucose levels. PMID:21810599

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.

Dietary and non-dietary factors associated with serum zinc in Indian women.

PubMed

Herbst, Catherine A; Menon, Kavitha C; Ferguson, Elaine L; Thomson, Christine D; Bailey, Karl; Gray, Andrew R; Zodpey, Sanjay; Saraf, Abhay; Das, Prabir Kumar; Skeaff, Sheila A

2014-10-01

Women in low-income settings, common in India, are at risk of inadequate zinc intake due to poor diet quality and low consumption of flesh foods rich in zinc. The aims of this study were to assess the prevalence of zinc status of non-pregnant rural and tribal women living in central India and to identify dietary and non-dietary factors associated with the biochemical zinc status of these women. Rural and tribal non-pregnant women 18-30 years of age were selected using proportion to population sampling near Nagpur, Maharashtra, India. Sociodemographic, biochemical (serum zinc), clinical, and dietary data (1-day interactive 24-h recall) were collected. The mean age of women (n = 109; rural = 52; tribal = 56) was 23.2 years and mean BMI was 17.9 kg/m(2). The majority of the participants identified as being non-vegetarian (72 %). The mean ± SD serum zinc concentration was 10.8 ± 1.6 μmol/L, and 52 % of participants had a low serum zinc concentration according to the International Zinc Nutrition Consultative Group (IZiNCG). The median (first and third quartile) energy, zinc intake, and phytate/zinc molar ratio was 5.4 (4.2, 6.7) MJ/day, 5.3 (3.8, 7.0) mg/day, and 26 (22, 28), respectively. Zinc intakes were well below IZiNCG recommendations for dietary zinc of 9 mg/day for non-pregnant women aged 14-18 years and 7 mg/day for non-pregnant women aged ≥ 19 years. Using linear regression analysis to identify non-dietary and dietary factors associated with serum zinc, a significant association was only found for current lactation (p = 0.012) and energy intake (p < 0.001). Diets low in energy with poor bioavailability of dietary zinc are likely to be the primary cause of the high proportion of Indian women with zinc deficiency.

Zinc Deficiency Is associated With Depressive Symptoms-Results From the Berlin Aging Study II.

PubMed

Jung, Alissa; Spira, Dominik; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja; Norman, Kristina

2017-08-01

Zinc plays an important role for behavioral and mental function, maintaining the correct functions of intracellular signal transduction, cellular and trans-membrane transport, protein synthesis, and antioxidant system. We investigated both dietary zinc intake and plasma zinc levels and the correlation with depressive symptoms in a large sample of community-dwelling old. One thousand five hundred fourteen older people (aged 60-84 years, 772 women) from the Berlin Aging Study II were included. Zinc intake was assessed by the EPIC Food Frequency Questionnaire. Plasma zinc levels were assessed with atomic-absorption spectrophotometry. Depressive symptoms were assessed with the "Center for Epidemiological Studies Depression Scale" and the "Geriatric Depression Scale." Zinc deficiency in blood plasma was found in 18.7% of participants, and depressive symptoms in 15.7%. Participants with depressive symptoms had lower energy-adjusted zinc intake (median 11.1 vs 11.6 µmol/L; p = .048) and lower plasma zinc levels (median 12.2 vs12.3 mg/dL; p = .037). Even after adjustment for known predictors of depression, plasma zinc deficiency remained significantly associated with depressive symptoms (odds ratio: 1.490, 95% confidence interval: 1.027-2.164; p = .036). In the multiple logistic regression model stratified by sex, we found that plasma zinc deficiency was strongly associated with a higher risk for depressive symptoms in women (odds ratio: 1.739, 95% confidence interval: 1.068-2.833; p = .026). Plasma zinc deficiency was common in our old study population. An increase in dietary zinc and higher plasma zinc levels may reduce the risk of depressive symptoms. A screening for reduced dietary zinc intake or plasma zinc deficiency might be beneficial in older people at risk of depressive symptoms. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of Dietary Zinc Manipulation on Growth Performance, Zinc Status and Immune Response during Giardia lamblia Infection: A Study in CD-1 Mice

PubMed Central

Iñigo-Figueroa, Gemma; Méndez-Estrada, Rosa O.; Quihui-Cota, Luis; Velásquez-Contreras, Carlos A.; Garibay-Escobar, Adriana; Canett-Romero, Rafael; Astiazarán-García, Humberto

2013-01-01

Associations between Giardia lamblia infection and low serum concentrations of zinc have been reported in young children. Interestingly, relatively few studies have examined the effects of different dietary zinc levels on the parasite-infected host. The aims of this study were to compare the growth performance and zinc status in response to varying levels of dietary zinc and to measure the antibody-mediated response of mice during G. lamblia infection. Male CD-1 mice were fed using 1 of 4 experimental diets: adequate-zinc (ZnA), low-zinc (ZnL), high-zinc (ZnH) and supplemented-zinc (ZnS) diet containing 30, 10, 223 and 1383 mg Zn/kg respectively. After a 10 days feeding period, mice were inoculated orally with 5 × 106 G. lamblia trophozoites and were maintained on the assigned diet during the course of infection (30 days). Giardia-free mice fed ZnL diets were able to attain normal growth and antibody-mediated response. Giardia-infected mice fed ZnL and ZnA diets presented a significant growth retardation compared to non-infected controls. Zinc supplementation avoided this weight loss during G. lamblia infection and up-regulated the host’s humoral immune response by improving the production of specific antibodies. Clinical outcomes of zinc supplementation during giardiasis included significant weight gain, higher anti-G. lamblia IgG antibodies and improved serum zinc levels despite the ongoing infection. A maximum growth rate and antibody-mediated response were attained in mice fed ZnH diet. No further increases in body weight, zinc status and humoral immune capacity were noted by feeding higher zinc levels (ZnS) than the ZnH diet. These findings probably reflect biological effect of zinc that could be of public health importance in endemic areas of infection. PMID:24002196

40 CFR 60.171 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.171 Definitions... and in subpart A of this part. (a) Primary zinc smelter means any installation engaged in the production, or any intermediate process in the production, of zinc or zinc oxide from zinc sulfide ore...

40 CFR 421.80 - Applicability: Description of the primary zinc subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... primary zinc subcategory. 421.80 Section 421.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Zinc Subcategory § 421.80 Applicability: Description of the primary zinc subcategory. The provisions of this subpart are applicable to discharges resulting from the production of primary zinc by either...

40 CFR 421.80 - Applicability: Description of the primary zinc subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... primary zinc subcategory. 421.80 Section 421.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Zinc Subcategory § 421.80 Applicability: Description of the primary zinc subcategory. The provisions of this subpart are applicable to discharges resulting from the production of primary zinc by either...

40 CFR 60.171 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and in subpart A of this part. (a) Primary zinc smelter means any installation engaged in the production, or any intermediate process in the production, of zinc or zinc oxide from zinc sulfide ore... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.171 Definitions...

Shifts in microbial community composition and function in the acidification of a lead/zinc mine tailings.

PubMed

Chen, Lin-Xing; Li, Jin-Tian; Chen, Ya-Ting; Huang, Li-Nan; Hua, Zheng-Shuang; Hu, Min; Shu, Wen-Sheng

2013-09-01

In an attempt to link the microbial community composition and function in mine tailings to the generation of acid mine drainage, we simultaneously explored the geochemistry and microbiology of six tailings collected from a lead/zinc mine, i.e. primary tailings (T1), slightly acidic tailings (T2), extremely acidic tailings (T3, T4 and T5) and orange-coloured oxidized tailings (T6). Geochemical results showed that the six tailings (from T1 to T6) likely represented sequential stages of the acidification process of the mine tailings. 16S rRNA pyrosequencing revealed a contrasting microbial composition between the six tailings: Proteobacteria-related sequences dominated T1-T3 with relative abundance ranging from 56 to 93%, whereas Ferroplasma-related sequences dominated T4-T6 with relative abundance ranging from 28 to 58%. Furthermore, metagenomic analysis of the microbial communities of T2 and T6 indicated that the genes encoding key enzymes for microbial carbon fixation, nitrogen fixation and sulfur oxidation in T2 were largely from Thiobacillus and Acidithiobacillus, Methylococcus capsulatus, and Thiobacillus denitrificans respectively; while those in T6 were mostly identified in Acidithiobacillus and Leptospirillum, Acidithiobacillus and Leptospirillum, and Acidithiobacillus respectively. The microbial communities in T2 and T6 harboured more genes suggesting diverse metabolic capacities for sulfur oxidation/heavy metal detoxification and tolerating low pH respectively. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

High-pressure Gas Activation for Amorphous Indium-Gallium-Zinc-Oxide Thin-Film Transistors at 100 °C

PubMed Central

Kim, Won-Gi; Tak, Young Jun; Du Ahn, Byung; Jung, Tae Soo; Chung, Kwun-Bum; Kim, Hyun Jae

2016-01-01

We investigated the use of high-pressure gases as an activation energy source for amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs). High-pressure annealing (HPA) in nitrogen (N2) and oxygen (O2) gases was applied to activate a-IGZO TFTs at 100 °C at pressures in the range from 0.5 to 4 MPa. Activation of the a-IGZO TFTs during HPA is attributed to the effect of the high-pressure environment, so that the activation energy is supplied from the kinetic energy of the gas molecules. We reduced the activation temperature from 300 °C to 100 °C via the use of HPA. The electrical characteristics of a-IGZO TFTs annealed in O2 at 2 MPa were superior to those annealed in N2 at 4 MPa, despite the lower pressure. For O2 HPA under 2 MPa at 100 °C, the field effect mobility and the threshold voltage shift under positive bias stress were improved by 9.00 to 10.58 cm2/V.s and 3.89 to 2.64 V, respectively. This is attributed to not only the effects of the pressurizing effect but also the metal-oxide construction effect which assists to facilitate the formation of channel layer and reduces oxygen vacancies, served as electron trap sites. PMID:26972476

The contribution of breakfast cereals to the nutritional intake of the materially deprived UK population.

PubMed

Holmes, B A; Kaffa, N; Campbell, K; Sanders, T A B

2012-01-01

Breakfast is an important source of micronutrients in the diet and its consumption has been linked to positive health outcomes. The present analysis investigated the contribution that breakfast cereals make to the nutrient intakes of the materially deprived (low income) UK population. Data for 3728 respondents aged 2 years and over from the UK Low Income Diet and Nutrition Survey (2003-2005) were analysed. Nutrient intakes of consumers and non-consumers of breakfast cereal were compared. Breakfast cereals were consumed by 49% of men, 58% of women, 80% of boys and 80% of girls, and median intakes were: 35, 25, 29 and 21 g/d, respectively. Consumers of breakfast cereals had higher intakes of thiamin, riboflavin, niacin, biotin, folate, vitamin B(6), vitamin B(12), iron and zinc than non-consumers. Breakfast cereal consumption was also related to higher intakes of calcium, attributable to higher milk consumption. The intake of wholegrain and high-fibre breakfast cereals was associated with a higher intake of non-starch polysaccharides. Intakes of niacin, biotin, calcium and zinc were higher but that of vitamin B(6) was lower among consumers of exclusively wholegrain and high-fibre breakfast cereals compared with consumers of other breakfast cereals. There were no significant differences observed in intakes of non-milk extrinsic sugars according to type of breakfast cereal consumed. Breakfast cereals make a significant contribution to the micronutrient intake of the low-income UK population.

Multifactorial Analysis of a Biomarker Pool for Alzheimer Disease Risk in a North Indian Population.

PubMed

Talwar, Puneet; Grover, Sandeep; Sinha, Juhi; Chandna, Puneet; Agarwal, Rachna; Kushwaha, Suman; Kukreti, Ritushree

2017-01-01

Alzheimer disease (AD) is a progressive neurodegenerative disease with a complex multifactorial etiology. Here, we aim to identify a biomarker pool comprised of genetic variants and blood biomarkers as predictor of AD risk. We performed a case-control study involving 108 cases and 159 non-demented healthy controls to examine the association of multiple biomarkers with AD risk. The APOE genotyping revealed that ε4 allele frequency was significantly high (p value = 0.0001, OR = 2.66, 95% CI 1.58-4.46) in AD as compared to controls, whereas ε2 (p = 0.0430, OR = 0.29, CI 0.07-1.10) was overrepresented in controls. In biochemical assays, significant differences in levels of total copper, free copper, zinc, copper/zinc ratio, iron, epidermal growth factor receptor (EGFR), leptin, and albumin were also observed. The AD risk score (ADRS) as a linear combination of 6 candidate markers involving age, education status, APOE ε4 allele, levels of iron, Cu/Zn ratio, and EGFR was created using stepwise linear discriminant analysis. The area under the ROC curve of the ADRS panel for predicting AD risk was significantly high (AUC = 0.84, p < 0.0001, 95% CI 0.78-0.89, sensitivity = 70.0%, specificity = 83.8%) compared to individual parameters. These findings support the multifactorial etiology of AD and demonstrate the ability of a panel involving 6 biomarkers to discriminate AD cases from non-demented healthy controls. © 2017 S. Karger AG, Basel.

Microwave assisted digestion followed by ICP-MS for determination of trace metals in atmospheric and lake ecosystem.

PubMed

Ahmed, Manan; Chin, Ying Hui; Guo, Xinxin; Zhao, Xing-Min

2017-05-01

The study of trace metals in the atmosphere and lake water is important due to their critical effects on humans, aquatic animals and the geochemical balance of ecosystems. The objective of this study was to investigate the concentration of trace metals in atmospheric and lake water samples during the rainy season (before and after precipitation) between November and December 2015. Typical methods of sample preparation for trace metal determination such as cloud point extraction, solid phase extraction and dispersive liquid-liquid micro-extraction are time-consuming and difficult to perform; therefore, there is a crucial need for development of more effective sample preparation procedure. A convection microwave assisted digestion procedure for extraction of trace metals was developed for use prior to inductively couple plasma-mass spectrometric determination. The result showed that metals like zinc (133.50-419.30μg/m 3 ) and aluminum (53.58-378.93μg/m 3 ) had higher concentrations in atmospheric samples as compared to lake samples before precipitation. On the other hand, the concentrations of zinc, aluminum, chromium and arsenic were significantly higher in lake samples after precipitation and lower in atmospheric samples. The relationship between physicochemical parameters (pH and turbidity) and heavy metal concentrations was investigated as well. Furthermore, enrichment factor analysis indicated that anthropogenic sources such as soil dust, biomass burning and fuel combustion influenced the metal concentrations in the atmosphere. Copyright © 2016. Published by Elsevier B.V.

High-pressure Gas Activation for Amorphous Indium-Gallium-Zinc-Oxide Thin-Film Transistors at 100 °C.

PubMed

Kim, Won-Gi; Tak, Young Jun; Du Ahn, Byung; Jung, Tae Soo; Chung, Kwun-Bum; Kim, Hyun Jae

2016-03-14

We investigated the use of high-pressure gases as an activation energy source for amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs). High-pressure annealing (HPA) in nitrogen (N2) and oxygen (O2) gases was applied to activate a-IGZO TFTs at 100 °C at pressures in the range from 0.5 to 4 MPa. Activation of the a-IGZO TFTs during HPA is attributed to the effect of the high-pressure environment, so that the activation energy is supplied from the kinetic energy of the gas molecules. We reduced the activation temperature from 300 °C to 100 °C via the use of HPA. The electrical characteristics of a-IGZO TFTs annealed in O2 at 2 MPa were superior to those annealed in N2 at 4 MPa, despite the lower pressure. For O2 HPA under 2 MPa at 100 °C, the field effect mobility and the threshold voltage shift under positive bias stress were improved by 9.00 to 10.58 cm(2)/V.s and 3.89 to 2.64 V, respectively. This is attributed to not only the effects of the pressurizing effect but also the metal-oxide construction effect which assists to facilitate the formation of channel layer and reduces oxygen vacancies, served as electron trap sites.

Effect of Tamarindus indica leaf powder on plasma concentrations of copper, zinc, and iron in fluorotic cows.

PubMed

Samal, Pinaki; Patra, R C; Gupta, A R; Mishra, S K; Jena, D; Satapathy, D

2016-10-01

The main objective of the study was to determine the deleterious effect of fluoride on plasma trace minerals of fluorotic cattle and to evaluate the effect of Tamarindus indica leaf powder toward correction of the same. A total of 30 cattle exhibiting chronic sign of fluorosis and 10 healthy cattle from nonfluorotic area were incorporated in this study. Fluorotic cattle were divided into three equal groups consisting of 10 cattle each. Group I from fluoride free area served as healthy control. The Group II received no treatment and served as disease control. Groups III and IV were supplemented with tamarind leaf powder at 15 g and 30 g/day with feed for 60 days. Plasma mineral status was evaluated after 60 days of treatment with double beam atomic absorption spectrophotometer. Statistical analysis of data revealed a significant (p<0.05) decrease in mean plasma copper (Cu) (0.344±0.007 ppm), zinc (Zn) (0.692±0.06 ppm), and iron (Fe) concentration (1.100±0.01 ppm) in fluorotic cattle in comparison to healthy cattle (0.58±0.010, 2.342±0.04, 1.406±0.04 ppm, respectively). Significant (p<0.05) increase in Cu, Zn, and Fe was recorded after supplementation of tamarind leaf powder to the fluorotic cattle. It was concluded that fluorotic cattle might be supplemented with T. indica leaf powder with feed for the correction of the decreased level of certain plasma minerals.

Sprayed zinc oxide films: Ultra-violet light-induced reversible surface wettability and platinum-sensitization-assisted improved liquefied petroleum gas response.

PubMed

Nakate, Umesh T; Patil, Pramila; Bulakhe, R N; Lokhande, C D; Kale, Sangeeta N; Naushad, Mu; Mane, Rajaram S

2016-10-15

We report the rapid (superhydrophobic to superhydrophilic) transition property and improvement in the liquefied petroleum gas (LPG) sensing response of zinc oxide (ZnO) nanorods (NRs) on UV-irradiation and platinum (Pt) surface sensitization, respectively. The morphological evolution of ZnO NRs is evidenced from the field emission scanning electron microscope and atomic force microscope digital images and for the structural elucidation X-ray diffraction pattern is used. Elemental survey mapping is obtained from energy dispersive X-ray analysis spectrum. The optical properties have been studied by UV-Visible and photoluminescence spectroscopy measurements. The rapid (120sec) conversion of superhydrophobic (154°) ZnO NRs film to superhydrophilic (7°) is obtained under UV light illumination and the superhydrophobicity is regained by storing sample in dark. The mechanism for switching wettability behavior of ZnO NRs has thoroughly been discussed. In second phase, Pt-sensitized ZnO NRs film has demonstrated considerable gas sensitivity at 260ppm concentration of LPG. At 623K operating temperature, the maximum LPG response of 58% and the response time of 49sec for 1040ppm LPG concentration of Pt- sensitized ZnO NRs film are obtained. This higher LPG response of Pt-sensitized ZnO NRs film over pristine is primarily due to electronic effect and catalytic effect (spill-over effect) caused by an additional of Pt on ZnO NRs film surface. Copyright © 2016 Elsevier Inc. All rights reserved.

Contamination and human health risk of lead in soils around lead/zinc smelting areas in China.

PubMed

Lei, Kai; Giubilato, Elisa; Critto, Andrea; Pan, Huiyun; Lin, Chunye

2016-07-01

Pb/Zn smelting, an important economic activity in China, has led to heavy environmental pollution. This research reviewed studies on soil Pb contamination at Pb/Zn smelting sites in China published during the period of 2000 to 2015 to clarify the total levels, spatial changes, and health risks for Pb contamination in soils at local and national scales. The results show that Pb contents in surface soils at 58 Pb/Zn smelting sites in China ranged from 7 to 312,452 mg kg(-1) with an arithmetic average, geometric average, and median of 1982, 404, and 428 mg kg(-1), respectively (n = 1011). Surface soil Pb content at these smelting sites decreased from an average of 2466 to 659 mg kg(-1), then to 463 mg kg(-1) as the distance from the smelters increased from <1000 to 1000∼2000 m, and then to >2000 m. With respect to variation with depth, the average soil Pb content at these sites gradually decreased from 986 mg kg(-1) at 0- to 20-cm depth to 144 mg kg(-1) at 80- to 100-cm depth. Approximately 78 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites were classified as having high Pb pollution levels. Approximately 34.2 and 7.7 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites might pose adverse health effects and high chronic risks to children, respectively. The Pb/Zn smelting sites in the southwest and southeast provinces of China, as well as Liaoning province, were most contaminated and thus should receive priority for remediation.

Comparative analysis of the IGF2 and ZBED6 gene variants and haplotypes reveals significant effect of growth traits in cattle.

PubMed

Huang, Yong-Zhen; Zhan, Zhao-Yang; Sun, Yu-Jia; Wang, Jing; Li, Ming-Xun; Lan, Xian-Yong; Lei, Chu-Zhao; Zhang, Chun-Lei; Chen, Hong

2013-06-01

Muscle growth is a complex phenomenon regulated by many factors, whereby net growth results from the combined action of synthesis and turnover. Insulin-like growth factor 2 (IGF2) is a fetal growth and differentiation factor that plays an important role in muscle growth and in myoblast proliferation and differentiation; Zinc finger, BED-type containing 6 (ZBED6) is a novel transcription factor that was identified and shown to act as a repressor of IGF2 transcription in skeletal muscle. In this study, a total of seven single nucleotide polymorphisms (SNPs) were identified, four SNPs in intron 8 of IGF2 and one promoter SNP and two missense mutations in the coding region of ZBED6, two of which were in complete linkage disequilibrium (LD) in the bovine IGF2. The 58 haplotypes were inferred in 1522 individuals representing four purebred cattle breeds from China. The seven SNPs, 79 and 66 combined diplotypes were revealed for association with body mass in Nanyang and Jiaxian cattle populations at five different ages (P < 0.05 or 0.01). The mutant-type variants and haplotype 58 (likely in LD with the beneficial quantitative trait nucleotide allele) was superior for body mass; the heterozygote diplotype of the most common haplotypes 58 was associated with higher body mass compared to either heterozygote or homozygote. The statistical analyses indicated that the mutant-type variants and haplotypes are significantly associated with body mass in study cattle populations at different ages. These data demonstrate that variants and haplotypes are associated with growth traits, and these results may provide important biological insights into the phenotypic differentiation that is associated with adaptation and specialization of cattle breeds.

40 CFR 471.80 - Applicability; description of the zinc forming subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the zinc... CATEGORY Zinc Forming Subcategory § 471.80 Applicability; description of the zinc forming subcategory. This... pollutants into publicly owned treatment works from the process operations of the zinc forming subcategory. ...

40 CFR 63.11164 - What General Provisions apply to primary zinc production facilities?

Code of Federal Regulations, 2011 CFR

2011-07-01

... primary zinc production facilities? 63.11164 Section 63.11164 Protection of Environment ENVIRONMENTAL... Primary Nonferrous Metals Area Sources-Zinc, Cadmium, and Beryllium Primary Zinc Production Facilities § 63.11164 What General Provisions apply to primary zinc production facilities? (a) If you own or...

40 CFR 63.11164 - What General Provisions apply to primary zinc production facilities?

Code of Federal Regulations, 2010 CFR

2010-07-01

... primary zinc production facilities? 63.11164 Section 63.11164 Protection of Environment ENVIRONMENTAL... Primary Nonferrous Metals Area Sources-Zinc, Cadmium, and Beryllium Primary Zinc Production Facilities § 63.11164 What General Provisions apply to primary zinc production facilities? (a) If you own or...

21 CFR 522.2690 - Zinc gluconate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Zinc gluconate. 522.2690 Section 522.2690 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.2690 Zinc gluconate. (a) Specifications. Each milliliter of solution contains 13.1 milligrams zinc as zinc gluconate...

40 CFR 415.670 - Applicability; description of the zinc chloride 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 Chloride Production Subcategory § 415.670 Applicability; description of the zinc chloride... of pollutants into treatment works which are publicly owned resulting from the production of zinc...

21 CFR 172.399 - Zinc methionine sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc methionine sulfate. 172.399 Section 172.399... CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

40 CFR 471.80 - Applicability; description of the zinc forming subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the zinc... CATEGORY Zinc Forming Subcategory § 471.80 Applicability; description of the zinc forming subcategory. This... pollutants into publicly owned treatment works from the process operations of the zinc forming subcategory. ...

21 CFR 522.2690 - Zinc gluconate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc gluconate. 522.2690 Section 522.2690 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.2690 Zinc gluconate. (a) Specifications. Each milliliter of solution contains 13.1 milligrams zinc as zinc gluconate...

40 CFR 63.11167 - What definitions apply to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... melt cadmium or produce cadmium oxide from the cadmium recovered in the zinc production process... engaged in the production, or any intermediate process in the production, of zinc or zinc oxide from zinc... Sources-Zinc, Cadmium, and Beryllium Other Requirements and Information § 63.11167 What definitions apply...

Excessive zinc ingestion: A reversible cause of sideroblastic anemia and bone marrow depression

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

Broun, E.R.; Greist, A.; Tricot, G.

1990-09-19

Two patients with sideroblastic anemia secondary to zinc-induced copper deficiency absorbed excess zinc secondary to oral ingestion. The source of excess zinc was a zinc supplement in one case; in the other, ingested coins. In each case, the sideroblastic anemia was corrected promptly after removal of the source of excess zinc. These two cases emphasize the importance of recognizing this clinical entity, since the myelodysplastic features are completely reversible.

Regeneration of zinc halide catalyst used in the hydrocracking of polynuclear hydrocarbons

DOEpatents

Gorin, Everett

1978-01-01

Improved recovery of spent molten zinc halide hydro-cracking catalyst is achieved in the oxidative vapor phase regeneration thereof by selective treatment of the zinc oxide carried over by the effluent vapors from the regeneration zone with hydrogen halide gas under conditions favoring the reaction of the zinc oxide with the hydrogen halide, whereby regenerated zinc halide is recovered in a solids-free state with little loss of zinc values.

The effect of polymers onto the size of zinc layered hydroxide salt and its calcined product

NASA Astrophysics Data System (ADS)

Hussein, Mohd Zobir bin; Ghotbi, Mohammad Yeganeh; Yahaya, Asmah Hj; Abd Rahman, Mohd Zaki

2009-02-01

Zinc hydroxide nitrate, a brucite-like layered material was synthesized using pH control method. Poly(vinyl alcohol) and poly(ethylene glycol) were used at various percentages as size decreasing agents during the synthesis of zinc hydroxide nitrate. SEM and PXRD showed the decrease of size and thickness of the resultant zinc hydroxide nitrates. TG and surface area data confirmed the decrease of the particle sizes, too. When zinc hydroxide nitrates were heat treated at 500 °C, the physical properties of nano zinc oxides obtained depended on the parent material, zinc hydroxide nitrate.

Zinc Therapy in Dermatology: A Review

PubMed Central

Mahajan, Vikram K.; Mehta, Karaninder S.; Chauhan, Pushpinder S.

2014-01-01

Zinc, both in elemental or in its salt forms, has been used as a therapeutic modality for centuries. Topical preparations like zinc oxide, calamine, or zinc pyrithione have been in use as photoprotecting, soothing agents or as active ingredient of antidandruff shampoos. Its use has expanded manifold over the years for a number of dermatological conditions including infections (leishmaniasis, warts), inflammatory dermatoses (acne vulgaris, rosacea), pigmentary disorders (melasma), and neoplasias (basal cell carcinoma). Although the role of oral zinc is well-established in human zinc deficiency syndromes including acrodermatitis enteropathica, it is only in recent years that importance of zinc as a micronutrient essential for infant growth and development has been recognized. The paper reviews various dermatological uses of zinc. PMID:25120566

Determination of zinc availability in foods by the extrinsic label technique.

PubMed

Evans, G W; Johnson, P E

1977-06-01

The absorption of intrinsic 65Zn and extrinsic 65Zn from corn and liver was measured in rats. No significant difference between the absorption of intrinsic- and extrinsic-label was observed. These results indicate that endogenous zinc and exogenous 65Zn enter a common pool prior to being absorbed from the intestine. Since extrinsic 65Zn enters a common pool with intrinsic zinc, whole-body absorption of extrinsic 65Zn can be used to obtain an accurate estimate of the availability of zinc in food. The availability of zinc in human breast milk, in cow's milk, in infant formulas, and in reconstituted dry milk was analyzed by use of the extrinsic label. The zinc in human breast milk was most available (59%) while the zinc in the infant formulas was the least available (26 to 37%). Zinc from both raw and cooked corn was more available than zinc from either cooked or uncooked rat liver.

Maternal and fetal plasma zinc in pre-eclampsia.

PubMed

Bassiouni, B A; Foda, A I; Rafei, A A

1979-04-01

Zinc is important for fetal growth and is involved in several important enzyme systems. Maternal and umbilical plasma zinc concentrations were determined in 52 parturient women with mild and severe pre-eclampsia, and were compared with those obtained from 20 women in labor whose pregnancies had progressed normally. A decrease in maternal as well as umbilical plasma zinc concentrations was observed in pre-eclamptic women, and this decrease was statistically significant in severe pre-eclampsia. The causes of these changes in plasma zinc concentrations in pre-eclampsia were discussed, and the possible adverse effects of zinc deficiency on the mother and fetus were mentioned. Low plasma zinc concentrations in pre-eclampsia may be a sign of zinc deficiency, implying possible risks to the mother and her fetus. It is recommended that maintenance of adequate dietary zinc nutrition during pregnancy, and particularly in pre-eclampsia, is important.

Zinc and Autophagy

PubMed Central

Liuzzi, Juan P.; Guo, Liang; Yoo, Changwon; Stewart, Tiffanie S

2014-01-01

Autophagy is a highly conserved degradative process through which cells overcome stressful conditions. Inasmuch as faulty autophagy has been associated with aging, neuronal degeneration disorders, diabetes, and fatty liver, autophagy is regarded as a potential therapeutic target. This review summarizes the present state of knowledge concerning the role of zinc in the regulation of autophagy, the role of autophagy in zinc metabolism, and the potential role of autophagy as a mediator of the protective effects of zinc. Data from in vitro studies consistently support the notion that zinc is critical for early and late autophagy. Studies have shown inhibition of early and late autophagy in cells cultured in medium treated with zinc chelators. Conversely, excess zinc added to the medium has shown to potentiate the stimulation of autophagy by tamoxifen, H2O2, ethanol and dopamine. The potential role of autophagy in zinc homeostasis has just begun to be investigated.Increasing evidence indicates that autophagy dysregulation causes significant changes in cellular zinc homeostasis. Autophagy may mediate the protective effect of zinc against lipid accumulation, apoptosis and inflammation by promoting degradation of lipid droplets, inflammasomes, p62/SQSTM1 and damaged mitochondria.Studies with humans and animal models are necessary to determine whether autophagy is influenced by zinc intake. PMID:25012760

Effect of low zinc intake and oral contraceptive agents on nitrogen utilization and clinical findings in young women.

PubMed

Hess, F M; King, J C; Margen, S

1977-12-01

In a previous paper we reported that serum, urine and fecal zinc levels fell markedly in women taking a combination oral contraceptive agent (+OCA) and in women with normal menstrual cycles (-OCA) when they consumed a low-zinc diet (less than 0.2 mg/day) for 35 days. We evaluated other biochemical and clinical data in order to determine if depletion of accessible body zinc and/or physiologic adjustment to conserve body zinc stores had occurred. Neither low zinc intake nor oral contraceptive use appeared to influence nitrogen balance or body weight. Use of contraceptive drugs appeared to influence the response of blood parameters to zinc depletion. Serum transferrin and cholesterol declined significantly in the -OCA group, whereas alkaline phosphatase and gamma-globulin changed significantly in both groups. Clinical problems developed in all the subjects with serum zinc levels below 50 microgram/dl during the study; three of the six with serum zinc levels above 50 microgram/dl also complained of clinical symptoms. The results suggest that zinc deficiency through depletion of accessible body zinc stores developed during the 35-day study.

Leptin, NPY, Melatonin and Zinc Levels in Experimental Hypothyroidism and Hyperthyroidism: The Relation to Zinc.

PubMed

Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

2017-06-01

Since zinc mediates the effects of many hormones or is found in the structure of numerous hormone receptors, zinc deficiency leads to various functional impairments in the hormone balance. And also thyroid hormones have important activity on metabolism and feeding. NPY and leptin are affective on food intake and regulation of appetite. The present study is conducted to determine how zinc supplementation and deficiency affect thyroid hormones (free and total T3 and T4), melatonin, leptin, and NPY levels in thyroid dysfunction in rats. The experiment groups in the study were formed as follows: Control (C); Hypothyroidism (PTU); Hypothyroidism+Zinc (PTU+Zn); Hypothyroidism+Zinc deficient; Hyperthyroidism (H); Hyperthyroidism+Zinc (H+Zn); and Hyperthyroidism+Zinc deficient. Thyroid hormone parameters (FT 3 , FT 4 , TT 3 , and TT 4 ) were found to be reduced in hypothyroidism groups and elevated in the hyperthyroidism groups. Melatonin values increased in hyperthyroidism and decreased in hypothyroidism. Leptin and NPY levels both increased in hypo- and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and increased in hyperthyroidism. Zinc supplementation, particularly when thyroid function is impaired, has been demonstrated to markedly prevent these changes.

Zinc deficiency-induced iron accumulation, a consequence of alterations in iron regulatory protein-binding activity, iron transporters, and iron storage proteins.

PubMed

Niles, Brad J; Clegg, Michael S; Hanna, Lynn A; Chou, Susan S; Momma, Tony Y; Hong, Heeok; Keen, Carl L

2008-02-22

One consequence of zinc deficiency is an elevation in cell and tissue iron concentrations. To examine the mechanism(s) underlying this phenomenon, Swiss 3T3 cells were cultured in zinc-deficient (D, 0.5 microM zinc), zinc-supplemented (S, 50 microM zinc), or control (C, 4 microM zinc) media. After 24 h of culture, cells in the D group were characterized by a 50% decrease in intracellular zinc and a 35% increase in intracellular iron relative to cells in the S and C groups. The increase in cellular iron was associated with increased transferrin receptor 1 protein and mRNA levels and increased ferritin light chain expression. The divalent metal transporter 1(+)iron-responsive element isoform mRNA was decreased during zinc deficiency-induced iron accumulation. Examination of zinc-deficient cells revealed increased binding of iron regulatory protein 2 (IRP2) and decreased binding of IRP1 to a consensus iron-responsive element. The increased IRP2-binding activity in zinc-deficient cells coincided with an increased level of IRP2 protein. The accumulation of IRP2 protein was independent of zinc deficiency-induced intracellular nitric oxide production but was attenuated by the addition of the antioxidant N-acetylcysteine or ascorbate to the D medium. These data support the concept that zinc deficiency can result in alterations in iron transporter, storage, and regulatory proteins, which facilitate iron accumulation.

Measurements of zinc absorption: application and interpretation in research designed to improve human zinc nutriture.

PubMed

Hambidge, K Michael; Miller, Leland V; Tran, Cuong D; Krebs, Nancy F

2005-11-01

The focus of this paper is on the application of measurements of zinc absorption in human research, especially studies designed to assess the efficacy of intervention strategies to prevent and manage zinc deficiency in populations. Emphasis is given to the measurement of quantities of zinc absorbed rather than restricting investigations to measurements of fractional absorption of zinc. This is especially important when determining absorption of zinc from the diet, whether it be the habitual diet or an intervention diet under evaluation. Moreover, measurements should encompass all meals for a minimum of one day with the exception of some pilot studies. Zinc absorption is primarily via an active saturable transport process into the enterocytes of the proximal small intestine. The relationship between quantity of zinc absorbed and the quantity ingested is best characterized by saturable binding models. When applied to human studies that have sufficient data to examine dose-response relationships, efficiency of absorption is high until approximately 50-60% maximal absorption is achieved, even with moderate phytate intakes. This also coincides approximately with the quantity of absorbed zinc necessary to meet physiologic requirements. Efficiency of absorption with intakes that exceed this level is low or very low. These observations have important practical implications for the design and interpretation of intervention studies to prevent zinc deficiency. They also suggest the potential utility of measurements of the quantity of zinc absorbed when evaluating the zinc status of populations.

Zinc Status Biomarkers and Cardiometabolic Risk Factors in Metabolic Syndrome: A Case Control Study

PubMed Central

Freitas, Erika P. S.; Cunha, Aline T. O.; Aquino, Sephora L. S.; Pedrosa, Lucia F. C.; Lima, Severina C. V. C.; Lima, Josivan G.; Almeida, Maria G.; Sena-Evangelista, Karine C. M.

2017-01-01

Metabolic syndrome (MS) involves pathophysiological alterations that might compromise zinc status. The aim of this study was to evaluate zinc status biomarkers and their associations with cardiometabolic factors in patients with MS. Our case control study included 88 patients with MS and 37 controls. We performed clinical and anthropometric assessments and obtained lipid, glycemic, and inflammatory profiles. We also evaluated zinc intake, plasma zinc, erythrocyte zinc, and 24-h urinary zinc excretion. The average zinc intake was significantly lower in the MS group (p < 0.001). Regression models indicated no significant differences in plasma zinc concentration (all p > 0.05) between the two groups. We found significantly higher erythrocyte zinc concentration in the MS group (p < 0.001) independent from co-variable adjustments. Twenty-four hour urinary zinc excretion was significantly higher in the MS group (p = 0.008), and adjustments for age and sex explained 21% of the difference (R2 = 0.21, p < 0.001). There were significant associations between zincuria and fasting blood glucose concentration (r = 0.479), waist circumference (r = 0.253), triglyceride concentration (r = 0.360), glycated hemoglobin concentration (r = 0.250), homeostatic model assessment—insulin resistance (r = 0.223), and high-sensitivity C-reactive protein concentration (r = 0.427) (all p < 0.05) in the MS group. Patients with MS had alterations in zinc metabolism mainly characterized by an increase in erythrocyte zinc and higher zincuria. PMID:28241426

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.

Dietary Zinc Intake and Its Association with Metabolic Syndrome Indicators among Chinese Adults: An Analysis of the China Nutritional Transition Cohort Survey 2015.

PubMed

Wang, Yun; Jia, Xiao-Fang; Zhang, Bing; Wang, Zhi-Hong; Zhang, Ji-Guo; Huang, Fei-Fei; Su, Chang; Ouyang, Yi-Fei; Zhao, Jian; Du, Wen-Wen; Li, Li; Jiang, Hong-Ru; Zhang, Ji; Wang, Hui-Jun

2018-05-08

The dietary zinc consumed in Chinese households has decreased over the past decade. However, the national dietary zinc intake in the last five years has seldom been investigated. Using data from 12,028 participants 18 to 64 years old (52.9% male) in the China Nutritional Transition Cohort Survey (CNTCS) 2015, we describe the intake of dietary zinc and the contributions of major foods and we examine the relationship between the level of dietary zinc intake and metabolic syndrome indicators, including blood pressure, fasting glucose, and triglycerides (TG), in Chinese adults. We assessed dietary zinc intake using 24 h recalls on three consecutive days. The mean daily dietary zinc intake for all participants was 10.2 milligrams per day (males 11.2 mg/day, females 9.4 mg/day, p < 0.001). The mean daily dietary zinc density for all participants was 5.2 mg/day per 1000 kilocalories. Among all participants, 31.0% were at risk of zinc deficiency, with dietary zinc intakes of less than the Estimated Average Requirement (EAR) (males 49.2%, females 14.8%, p < 0.050), and 49.9% had adequate dietary zinc intakes, equal to or greater than the recommended nutrient intake (RNI) (males 30.7%, females 67.0%, p < 0.050). We found substantial gender differences in dietary zinc intake and zinc deficiency, with nearly half of the men at risk of zinc deficiency. Males of younger age, with higher education and incomes, and who consumed higher levels of meat, had higher zinc intakes, higher zinc intake densities, and higher rates of meeting the EAR. Among all participants, grains, livestock meat, fresh vegetables, legumes, and seafood were the top five food sources of zinc, and their contributions to total dietary zinc intake were 39.5%, 17.3%, 8.9%, 6.4%, and 4.8%, respectively. The groups with relatively better dietary zinc intakes consumed lower proportions of grains and higher proportions of livestock meat. For males with adequate dietary zinc intake (≥RNI), TG levels increased by 0.219 millimoles per liter (mmol/L) compared with males with deficient dietary zinc intake (

Zinc regulates Nox1 expression through a NF-κB and mitochondrial ROS dependent mechanism to induce senescence of vascular smooth muscle cells.

PubMed

Salazar, G; Huang, J; Feresin, R G; Zhao, Y; Griendling, K K

2017-07-01

The role of oxidative stress and inflammation in the development and progression of cardiovascular diseases (CVD) is well established. Increases in oxidative stress can further exacerbate the inflammatory response and lead to cellular senescence. We previously reported that angiotensin II (Ang II) and zinc increase reactive oxygen species (ROS) and cause senescence of vascular smooth muscle cells (VSMCs) and that senescence induced by Ang II is a zinc-dependent process. Zinc stimulated NADPH oxidase (Nox) activity; however, the role of Nox isoforms in zinc effects was not determined. Here, we show that downregulation of Nox1, but not Nox4, by siRNA prevented both Ang II- and zinc-induced senescence in VSMCs. On the other hand, overexpression of Nox1 induced senescence, which was associated with reduced proliferation, reduced expression of telomerase and increased DNA damage. Zinc increased Nox1 protein expression, which was inhibited by chelation of zinc with TPEN and by overexpression of the zinc exporters ZnT3 and ZnT10. These transporters work to reduce cytosolic zinc, suggesting that increased cytosolic zinc mediates Nox1 upregulation. Other metals including copper, iron, cobalt and manganese failed to upregulate Nox1, suggesting that this pathway is zinc specific. Nox1 upregulation was inhibited by actinomycin D (ACD), an inhibitor of transcription, by inhibition of NF-κB, a known Nox1 transcriptional regulator and by N-acetyl cysteine (NAC) and MitoTEMPO, suggesting that NF-κB and mitochondrial ROS mediate zinc effects. Supporting this idea, we found that zinc increased NF-κB activation in the cytosol, stimulated the translocation of the p65 subunit to the nucleus, and that zinc accumulated in mitochondria increasing mitochondrial ROS, measured using MitoSox. Further, zinc-induced senescence was reduced by inhibition of NF-κB or reduction of mitochondrial ROS with MitoTEMPO. NF-κB activity was also reduced by MitoTEMPO, suggesting that mitochondrial ROS is upstream of NF-κB. Our data demonstrate that altered zinc distribution leading to accumulation of zinc in the mitochondria increases mitochondrial ROS production causing NF-κB activation which in turn upregulates Nox1 expression inducing senescence of VSMCs. Copyright © 2017 Elsevier Inc. All rights reserved.

Zinc deficiency in the pediatric age group is common but underevaluated.

PubMed

Vuralli, Dogus; Tumer, Leyla; Hasanoglu, Alev

2017-08-01

Subclinical micronutrient deficiencies have been gradually becoming more important as a public health problem and drawing attention of the health authorities. Today it has been known that detecting and treating people having deficiency symptoms alone is no longer sufficient. It is important to detect and prevent any deficiency before it displays clinical manifestations. Zinc deficiency is one of the most widespread micronutrient deficiencies. In this study, we aimed to evaluate the zinc status and the associated factors in healthy school-age children. The study was carried out in schools in Altindag, the district of Ankara. A total of 1063 healthy children, 585 girls and 478 boys, aged 5-16 years were included in the study. Serum zinc, high-sensitivity C-reactive protein levels and white blood cell count were measured. A serum zinc level <65 μg/dL was considered as subclinical zinc deficiency for children <10 years of age. For children ≥10 years of age the cutoffs for serum zinc concentration were set at 66 μg/dL for females and 70 μg/dL for males. A questionnaire was developed to collect socioeconomic and demographic information of the participants. The prevalence of subclinical zinc deficiency in children attending the study was detected to be 27.8%. This high ratio showed zinc deficiency was an important health problem in the Altindag district of Ankara, Turkey. Evaluating the indicators of zinc deficiency such as serum zinc concentration, dietary zinc intake and stunting prevalence, this study is the most comprehensive epidemiological study performed in children in Turkey. This study reveals the high prevalence of subclinical zinc deficiency and indicates that zinc deficiency is a public health concern for the study population.

Dietary phytate, zinc and hidden zinc deficiency.

PubMed

Sandstead, Harold H; Freeland-Graves, Jeanne H

2014-10-01

Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

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

Lopez, A.L.; Kohrs, M.B.; Horwitz, D.L.

To determine the effect of glucose loading on serum zinc concentrations, 34 elderly subjects aged 60-86 y were studied. Anthropometric data, medical and dietary histories were obtained. Serum zinc and glucose concentrations were obtained fasting and 1/2, 1, 1 1/2, 2 and 3 h after 75 g oral glucose load; glycohemoglobin and fasting serum lipids were also determined. For comparison, the subjects were categorized as: normal or low serum zinc concentrations; normal or high body mass index BMI; normal or high sum of skinfolds and normal or high serum cholesterol. Results showed that low serum zinc concentrations increased significantly overmore » baseline values after the glucose load and did not return to fasting levels. On the other hand, mean serum zinc concentrations significantly declined without recovery for those with normal zinc values. For the total group, no significant differences were noted between fasting values and subsequent time periods. No correlations were noted between fasting serum zinc and area under the curve for zinc except in the high BMI group (positive correlation observed). For the high BMI group, fasting serum zinc differed significantly from the succeeding measurements except for 30 min. For the group as a whole, mean serum zinc concentration was within normal limits (76.9 +/- 2.8 mcg/ml): mean zinc intake was less than 2/3rds the RDA. They conclude that glucose ingestion may alter serum zinc and should be considered in interpreting these levels.« less

Effects of Different Zinc Species on Cellar Zinc Distribution, Cell Cycle, Apoptosis and Viability in MDAMB231 Cells.

PubMed

Wang, Yan-hong; Zhao, Wen-jie; Zheng, Wei-juan; Mao, Li; Lian, Hong-zhen; Hu, Xin; Hua, Zi-chun

2016-03-01

Intracellular metal elements exist in mammalian cells with the concentration range from picomoles per litre to micromoles per litre and play a considerable role in various biological procedures. Element provided by different species can influence the availability and distribution of the element in a cell and could lead to different biological effects on the cell's growth and function. Zinc as an abundant and widely distributed essential trace element, is involved in numerous and relevant physiological functions. Zinc homeostasis in cells, which is regulated by metallothioneins, zinc transporter/SLC30A, Zrt-/Irt-like proteins/SLC39A and metal-response element-binding transcription factor-1 (MTF-1), is crucial for normal cellular functioning. In this study, we investigated the influences of different zinc species, zinc sulphate, zinc gluconate and bacitracin zinc, which represented inorganic, organic and biological zinc species, respectively, on cell cycle, viability and apoptosis in MDAMB231 cells. It was found that the responses of cell cycle, apoptosis and death to different zinc species in MDAMB231 cells are different. Western blot analysis of the expression of several key proteins in regulating zinc-related transcription, cell cycle, apoptosis, including MTF-1, cyclin B1, cyclin D1, caspase-8 and caspase-9 in treated cells further confirmed the observed results on cell level.

Zinc

MedlinePlus

... Using toothpastes containing zinc, with or without an antibacterial agent, appears to prevent plaque and gingivitis. Some ... is some evidence that zinc has some antiviral activity against the herpes virus. Low zinc levels can ...

Regeneration of zinc chloride hydrocracking catalyst

DOEpatents

Zielke, Clyde W.

1979-01-01

Improved rate of recovery of zinc values from the solids which are carried over by the effluent vapors from the oxidative vapor phase regeneration of spent zinc chloride catalyst is achieved by treatment of the solids with both hydrogen chloride and calcium chloride to selectively and rapidly recover the zinc values as zinc chloride.

High mobility and high stability glassy metal-oxynitride materials and devices

NASA Astrophysics Data System (ADS)

Lee, Eunha; Kim, Taeho; Benayad, Anass; Hur, Jihyun; Park, Gyeong-Su; Jeon, Sanghun

2016-04-01

In thin film technology, future semiconductor and display products with high performance, high density, large area, and ultra high definition with three-dimensional functionalities require high performance thin film transistors (TFTs) with high stability. Zinc oxynitride, a composite of zinc oxide and zinc nitride, has been conceded as a strong substitute to conventional semiconductor film such as silicon and indium gallium zinc oxide due to high mobility value. However, zinc oxynitride has been suffered from poor reproducibility due to relatively low binding energy of nitrogen with zinc, resulting in the instability of composition and its device performance. Here we performed post argon plasma process on zinc oxynitride film, forming nano-crystalline structure in stable amorphous matrix which hampers the reaction of oxygen with zinc. Therefore, material properties and device performance of zinc oxynitride are greatly enhanced, exhibiting robust compositional stability even exposure to air, uniform phase, high electron mobility, negligible fast transient charging and low noise characteristics. Furthermore, We expect high mobility and high stability zinc oxynitride customized by plasma process to be applicable to a broad range of semiconductor and display devices.

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

Zinc-based electrolyte compositions, and related electrochemical processes and articles

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

Kniajanski, Sergei; Soloveichik, Grigorii Lev

An aqueous electrolyte composition is described, including a zinc salt based on zinc acetate or zinc glocolate. The saturation concentration of zinc in the electrolyte composition is in the range of about 2.5M to about 3.5M. The composition also contains at least one salt of a monovalent cation. The molar ratio of zinc to the monovalent cation is about 1:2. An aqueous zinc electroplating bath, containing the aqueous electrolyte composition, is also disclosed, along with a method for the electrochemical deposition of zinc onto a substrate surface, using the electroplating bath. Related flow batteries are also described, including a catholyte,more » as well as an anolyte based on the aqueous electrolyte composition, with a membrane between the catholyte and the anolyte.« less

Avoiding short circuits from zinc metal dendrites in anode by backside-plating configuration

PubMed Central

Higashi, Shougo; Lee, Seok Woo; Lee, Jang Soo; Takechi, Kensuke; Cui, Yi

2016-01-01

Portable power sources and grid-scale storage both require batteries combining high energy density and low cost. Zinc metal battery systems are attractive due to the low cost of zinc and its high charge-storage capacity. However, under repeated plating and stripping, zinc metal anodes undergo a well-known problem, zinc dendrite formation, causing internal shorting. Here we show a backside-plating configuration that enables long-term cycling of zinc metal batteries without shorting. We demonstrate 800 stable cycles of nickel–zinc batteries with good power rate (20 mA cm−2, 20 C rate for our anodes). Such a backside-plating method can be applied to not only zinc metal systems but also other metal-based electrodes suffering from internal short circuits. PMID:27263471

Serum zinc, copper and iron status of children with coeliac disease on three months of gluten-free diet with or without four weeks of zinc supplements: a randomised controlled trial.

PubMed

Negi, K; Kumar, R; Sharma, L; Datta, S P; Choudhury, M; Kumar, P

2018-04-01

Data about the effect of zinc supplementation with gluten-free diet on normalisation of plasma zinc, copper and iron in patients with coeliac disease are scanty. We evaluated the effect of zinc supplementation on serum zinc, copper and iron levels in patients with coeliac disease, by randomising 71 children newly diagnosed with coeliac disease into two groups: Group A = gluten-free diet (GFD); and Group B = gluten-free diet with zinc supplements (GFD +Zn). The rise in iron and zinc was significantly higher in the latter, but the mean rise of copper levels was slightly higher in the former, but the difference was not significant.

Process for preparing zinc oxide-based sorbents

DOEpatents

Gangwal, Santosh Kumar [Cary, NC; Turk, Brian Scott [Durham, NC; Gupta, Raghubir Prasad [Durham, NC

2011-06-07

The disclosure relates to zinc oxide-based sorbents, and processes for preparing and using them. The sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents comprise an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl.sub.2O.sub.4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, comprising a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

Avoiding short circuits from zinc metal dendrites in anode by backside-plating configuration

NASA Astrophysics Data System (ADS)

Higashi, Shougo; Lee, Seok Woo; Lee, Jang Soo; Takechi, Kensuke; Cui, Yi

2016-06-01

Portable power sources and grid-scale storage both require batteries combining high energy density and low cost. Zinc metal battery systems are attractive due to the low cost of zinc and its high charge-storage capacity. However, under repeated plating and stripping, zinc metal anodes undergo a well-known problem, zinc dendrite formation, causing internal shorting. Here we show a backside-plating configuration that enables long-term cycling of zinc metal batteries without shorting. We demonstrate 800 stable cycles of nickel-zinc batteries with good power rate (20 mA cm-2, 20 C rate for our anodes). Such a backside-plating method can be applied to not only zinc metal systems but also other metal-based electrodes suffering from internal short circuits.

Preparation of ionic membranes for zinc/bromine storage batteries

NASA Astrophysics Data System (ADS)

Assink, R. A.; Arnold, C., Jr.

Zinc/bromine flow batteries are being developed for vehicular and utility load leveling applications. During charge, an aqueous zinc bromide salt is electrolyzed to zinc metal and molecular bromine. During discharge, the zinc and bromine react to again form the zinc bromide salt. One serious disadvantage of the microporous separators presently used in the zinc/bromine battery is that modest amounts of bromine and negatively charged bromine moieties permeate through these materials and react with the zinc anode. This results in partial self-discharge of the battery and low coulombic efficiencies. Our approach to this problem is to impregnate the microporous separators with a soluble cationic polyelectrolyte. In laboratory screening tests a sulfonated polysulfone resin and fully fluorinated sulfonic acid polymer substantially reduced bromine permeation with only modest increases in the area resistance.

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

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.

Improved synthesis of fine zinc borate particles using seed crystals

NASA Astrophysics Data System (ADS)

Gürhan, Deniz; Çakal, Gaye Ö.; Eroğlu, İnci; Özkar, Saim

2009-03-01

Zinc borate is a flame retardant additive used in polymers, wood applications and textile products. There are different types of zinc borate having different chemical compositions and structures. In this study, the production of zinc borate having the molecular formula of 2ZnO·3B 2O 3·3.5H 2O was reexamined by studying the effects of reaction parameters on the properties of product as well as the reaction kinetics. Production of zinc borate from the reaction of boric acid and zinc oxide in the presence of seed crystals was performed in a continuously stirred, temperature-controlled batch reactor having a volume of 1.5 L. Samples taken in regular time intervals during the experiments were analyzed for the concentration of zinc oxide and boron oxide in the solid as well as for the conversion of zinc oxide to zinc borate versus time. The zinc borate production reaction was fit to the logistic model. The reaction rate, reaction completion time, composition and particle size distribution of zinc borate product were determined by varying the following parameters: the boric acid to zinc oxide ratio (H 3BO 3:ZnO=3:1, 3.5:1, 5:1 and 7:1), the particle size of zinc oxide (10 and 25 μm), stirring rate (275, 400, 800 and 1600 rpm), temperature (75, 85 and 95 °C) and the size of seed crystals (10 and 2 μm). The products were also analyzed for particle size distribution. The experimental results showed that the reaction rate increases with the increase in H 3BO 3:ZnO ratio, particle size of zinc oxide, stirring rate and temperature. Concomitantly, the reaction completion time is decreased by increasing the H 3BO 3:ZnO ratio, stirring rate and temperature. The average particle sizes of the zinc borate products are in the range 4.3-16.6 μm (wet dispersion analysis).

Influence of zinc on the calcium carbonate biomineralization of Halomonas halophila

PubMed Central

2012-01-01

Background The salt tolerance of halophilic bacteria make them promising candidates for technical applications, like isolation of salt tolerant enzymes or remediation of contaminated saline soils and waters. Furthermore, some halophilic bacteria synthesize inorganic solids resulting in organic–inorganic hybrids. This process is known as biomineralization, which is induced and/or controlled by the organism. The adaption of the soft and eco-friendly reaction conditions of this formation process to technical syntheses of inorganic nano materials is desirable. In addition, environmental contaminations can be entrapped in biomineralization products which facilitate the subsequent removal from waste waters. The moderately halophilic bacteria Halomonas halophila mineralize calcium carbonate in the calcite polymorph. The biomineralization process was investigated in the presence of zinc ions as a toxic model contaminant. In particular, the time course of the mineralization process and the influence of zinc on the mineralized inorganic materials have been focused in this study. Results H. halophila can adapt to zinc contaminated medium, maintaining the ability for biomineralization of calcium carbonate. Adapted cultures show only a low influence of zinc on the growth rate. In the time course of cultivation, zinc ions accumulated on the bacterial surface while the medium depleted in the zinc contamination. Intracellular zinc concentrations were below the detection limit, suggesting that zinc was mainly bound extracellular. Zinc ions influence the biomineralization process. In the presence of zinc, the polymorphs monohydrocalcite and vaterite were mineralized, instead of calcite which is synthesized in zinc-free medium. Conclusions We have demonstrated that the bacterial mineralization process can be influenced by zinc ions resulting in the modification of the synthesized calcium carbonate polymorph. In addition, the shape of the mineralized inorganic material is chancing through the presence of zinc ions. Furthermore, the moderately halophilic bacterium H. halophila can be applied for the decontamination of zinc from aqueous solutions. PMID:23198844

Zinc supplementation in public health.

PubMed

Penny, Mary Edith

2013-01-01

Zinc is necessary for physiological processes including defense against infections. Zinc deficiency is responsible for 4% of global child morbidity and mortality. Zinc supplements given for 10-14 days together with low-osmolarity oral rehydration solution (Lo-ORS) are recommended for the treatment of childhood diarrhea. In children aged ≥ 6 months, daily zinc supplements reduce the duration of acute diarrhea episodes by 12 h and persistent diarrhea by 17 h. Zinc supplements could reduce diarrhea mortality in children aged 12-59 months by an estimated 23%; they are very safe but are associated with an increase in vomiting especially with the first dose. Heterogeneity between the results of trials is not understood but may be related to dose and the etiology of the diarrhea infection. Integration of zinc and Lo-ORS into national programs is underway but slowly, procurement problems are being overcome and the greatest challenge is changing health provider and caregiver attitudes to diarrhea management. Fewer trials have been conducted of zinc adjunct therapy in severe respiratory tract infections and there is as yet insufficient evidence to recommend addition of zinc to antibiotic therapy. Daily zinc supplements for all children >12 months of age in zinc deficient populations are estimated to reduce diarrhea incidence by 11-23%. The greatest impact is in reducing multiple episodes of diarrhea. The effect on duration of diarrheal episodes is less clear, but there may be up to 9% reduction. Zinc is also efficacious in reducing dysentery and persistent diarrhea. Zinc supplements may also prevent pneumonia by about 19%, but heterogeneity across studies has not yet been explained. When analyses are restricted to better quality studies using CHERG (Child Health Epidemiology Reference Group) methodology, zinc supplements are estimated to reduce diarrheal deaths by 13% and pneumonia deaths by 20%. National-level programs to combat childhood zinc deficiency should be accelerated. Copyright © 2013 S. Karger AG, Basel.

Effects of serum zinc level on tinnitus.

PubMed

Berkiten, Güler; Kumral, Tolgar Lütfi; Yıldırım, Güven; Salturk, Ziya; Uyar, Yavuz; Atar, Yavuz

2015-01-01

The aim of this study was to assess zinc levels in tinnitus patients, and to evaluate the effects of zinc deficiency on tinnitus and hearing loss. One-hundred patients, who presented to an outpatient clinic with tinnitus between June 2009 and 2014, were included in the study. Patients were divided into three groups according to age: Group I (patients between 18 and 30years of age); Group II (patients between 31 and 60years of age); and Group III (patients between 61 and 78years of age). Following a complete ear, nose and throat examination, serum zinc levels were measured and the severity of tinnitus was quantified using the Tinnitus Severity Index Questionnaire (TSIQ). Patients were subsequently asked to provide a subjective judgment regarding the loudness of their tinnitus. The hearing status of patients was evaluated by audiometry and high-frequency audiometry. An average hearing sensitivity was calculated as the mean value of hearing thresholds between 250 and 20,000Hz. Serum zinc levels between 70 and 120μg/dl were considered normal. The severity and loudness of tinnitus, and the hearing thresholds of the normal zinc level and zinc-deficient groups, were compared. Twelve of 100 (12%) patients exhibited low zinc levels. The mean age of the zinc-deficient group was 65.41±12.77years. Serum zinc levels were significantly lower in group III (p<0.01). The severity and loudness of tinnitus were greater in zinc-deficient patients (p=0.011 and p=0.015, respectively). Moreover, the mean thresholds of air conduction were significantly higher in zinc-deficient patients (p=0.000). We observed that zinc levels decrease as age increases. In addition, there was a significant correlation between zinc level and the severity and loudness of tinnitus. Zinc deficiency was also associated with impairments in hearing thresholds. Copyright © 2015 Elsevier Inc. All rights reserved.

Endogenous Zinc in Neurological Diseases

PubMed Central

2005-01-01

The use of zinc in medicinal skin cream was mentioned in Egyptian papyri from 2000 BC (for example, the Smith Papyrus), and zinc has apparently been used fairly steadily throughout Roman and modern times (for example, as the American lotion named for its zinc ore, 'Calamine'). It is, therefore, somewhat ironic that zinc is a relatively late addition to the pantheon of signal ions in biology and medicine. However, the number of biological functions, health implications and pharmacological targets that are emerging for zinc indicate that it might turn out to be 'the calcium of the twenty-first century'. Here neurobiological roles of endogenous zinc is summarized. PMID:20396459

Effects of Zinc Chelators on Aflatoxin Production in Aspergillus parasiticus

PubMed Central

Wee, Josephine; Day, Devin M.; Linz, John E.

2016-01-01

Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N′,N′-tetrakis (2-pyridylmethyl) ethane-1,2-diamine (TPEN) and 2,3-dimercapto-1-propanesulfonic acid (DMPS) to explore the effect of zinc limitation on aflatoxin synthesis in Aspergillus parasiticus. TPEN but not DMPS decreased aflatoxin biosynthesis up to six-fold depending on whether A. parasiticus was grown on rich or minimal medium. Although we observed significant inhibition of aflatoxin production by TPEN, no detectable changes were observed in expression levels of the aflatoxin pathway gene ver-1 and the zinc binuclear cluster transcription factor, AflR. Treatment of growing A. parasiticus solid culture with a fluorescent zinc probe demonstrated an increase in intracellular zinc levels assessed by increases in fluorescent intensity of cultures treated with TPEN compared to controls. These data suggest that TPEN binds to cytoplasmic zinc therefore limiting fungal access to zinc. To investigate the efficacy of TPEN on food and feed crops, we found that TPEN effectively decreases aflatoxin accumulation on peanut medium but not in a sunflower seeds-derived medium. From an application perspective, these data provide the basis for biological differences that exist in the efficacy of different zinc chelators in various food and feed crops frequently contaminated by aflatoxin. PMID:27271668

The influence of inflammation on plasma zinc concentration in apparently healthy, HIV+ Kenyan adults and zinc responses after a multi-micronutrient supplement.

PubMed

Mburu, A S W; Thurnham, D I; Mwaniki, D L; Muniu, E M; Alumasa, F M

2010-05-01

Plasma zinc is an important biomarker of zinc status, but the concentration is depressed by inflammation. Apparently healthy adults, who tested positive twice for human immunodeficiency virus (HIV) but who had not reached stage IV or clinical AIDS, were randomly allocated to receive a food supplement (n=17 and 21) or the food plus a micronutrient capsule (MN; n=10 men and n=33 women) containing 15 mg zinc/day. We used the inflammation biomarkers, C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP), to identify subjects with and without inflammation and determine the effect of inflammation on the response of plasma zinc concentrations to the MN and food supplements. There were no differences between men and women either in plasma zinc or in the responses to the supplements and their data were combined. Plasma zinc was lower in those with inflammation than without. Repeated measures analysis of variance (ANOVA) showed that inflammation blocked increases in plasma zinc, and there was an approximate 10% increase in plasma zinc concentration in response to the MN supplement (P=0.023) in those without inflammation. Subgroup analysis showed mean changes in plasma zinc of 0.95 and -0.83 micromol/l (P=0.031) in response to the MN and food treatments, respectively, in those without inflammation at both time points. Inflammation seems to block any increase in plasma zinc after MN supplement and it is important to identify those without inflammation to determine the effectiveness of a zinc supplementation program.

Boutons containing vesicular zinc define a subpopulation of synapses with low AMPAR content in rat hippocampus.

PubMed

Sindreu, Carlos Balet; Varoqui, Hélène; Erickson, Jeffrey D; Pérez-Clausell, Jeús

2003-08-01

Cortical regions of the brain stand out for their high content in synaptic zinc, which may thus be involved in synaptic function. The relative number, chemical nature and transmitter receptor profile of synapses that sequester vesicular zinc are largely unknown. To address this, we combined pre-embedding zinc histochemistry and post-embedding immunogold electron microscopy in rat hippocampus. All giant mossy fibre (MF) terminals in the CA3 region and approximately 45% of boutons making axospinous synapses in stratum radiatum in CA1 contained synaptic vesicles that stained for zinc. Both types of zinc-positive boutons selectively expressed the vesicular zinc transporter ZnT-3. Zinc-positive boutons further immunoreacted to the vesicular glutamate transporter VGLUT-1, but not to the transmitter gamma-aminobutyric acid. Most dendritic spines in CA1 immunoreacted to alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) subunits GluR1-3 (approximately 80%) and to N-methyl-D-aspartate receptor (NMDAR) subunits NR1 + NR2A/B (approximately 90%). Synapses made by zinc-positive boutons contained 40% less AMPAR particles than those made by zinc-negative boutons, whereas NMDAR counts were similar. Further analysis indicated that this was due to the reduced synaptic expression of both GluR1 and GluR2 subunits. Hence, the levels of postsynaptic AMPARs may vary according to the presence of vesicular zinc in excitatory afferents to CA1. Zinc-positive and zinc-negative synapses may represent two glutamatergic subpopulations with distinct synaptic signalling.

Improved colorimetric determination of serum zinc.

PubMed

Johnson, D J; Djuh, Y Y; Bruton, J; Williams, H L

1977-07-01

We show how zinc may easily be quantified in serum by first using an optimum concentration of guanidine hydrochloride to cause release of zinc from proteins, followed by complexation of released metals with cyanide. The cyanide complex of zinc is preferentially demasked with chloral hydrate, followed by a colorimetric reaction between zinc and 4-(2-pyridylazo)resorcinol. This is a sensitive water-soluble ligand; its complex with zinc has an absorption maximum at 497 nm. Values found by this technique compare favorably with those obtained by atomic absorption spectroscopy.

Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

DOEpatents

Adler, Thomas C.; McLarnon, Frank R.; Cairns, Elton J.

1994-01-01

An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing KOH and a combination of KF and K.sub.2 CO.sub.3 salts which inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics.

Response of hippocampal mossy fiber zinc to excessive glutamate release.

PubMed

Takeda, Atsushi; Minami, Akira; Sakurada, Naomi; Nakajima, Satoko; Oku, Naoto

2007-01-01

The response of hippocampal mossy fiber zinc to excessive glutamate release was examined to understand the role of the zinc in excessive excitation in the hippocampus. Extracellular zinc and glutamate concentrations during excessive stimulation with high K(+) were compared between the hippocampal CA3 and CA1 by the in vivo microdialysis. Zinc concentration in the CA3 was more increased than that in the CA1, while glutamate concentration in the CA3 was less increased than that in the CA1. It is likely that more increase in extracellular zinc is linked with less increase in extracellular glutamate in the CA3. To see zinc action in mossy fiber synapses during excessive excitation, furthermore, 1mM glutamate was regionally delivered to the stratum lucidum in the presence of zinc or CaEDTA, a membrane-impermeable zinc chelator, and intracellular calcium signal was measured in the CA3 pyramidal cell layer. The persistent increase in calcium signal during stimulation with glutamate was significantly attenuated in the presence of 100 microM zinc, while significantly enhanced in the presence of 1mM CaEDTA. These results suggest that zinc released from mossy fibers attenuates the increase in intracellular calcium signal in mossy fiber synapses and postsynaptic CA3 neurons after excessive inputs to dentate granular cells.

The Adc/Lmb System Mediates Zinc Acquisition in Streptococcus agalactiae and Contributes to Bacterial Growth and Survival

PubMed Central

Moulin, Pauline; Patron, Kévin; Cano, Camille; Zorgani, Mohamed Amine; Camiade, Emilie; Borezée-Durant, Elise; Rosenau, Agnès; Mereghetti, Laurent

2016-01-01

ABSTRACT The Lmb protein of Streptococcus agalactiae is described as an adhesin that binds laminin, a component of the human extracellular matrix. In this study, we revealed a new role for this protein in zinc uptake. We also identified two Lmb homologs, AdcA and AdcAII, redundant binding proteins that combine with the AdcCB translocon to form a zinc-ABC transporter. Expression of this transporter is controlled by the zinc concentration in the medium through the zinc-dependent regulator AdcR. Triple deletion of lmb, adcA, and adcAII, or that of the adcCB genes, impaired growth and cell separation in a zinc-restricted environment. Moreover, we found that this Adc zinc-ABC transporter promotes S. agalactiae growth and survival in some human biological fluids, suggesting that it contributes to the infection process. These results indicated that zinc has biologically vital functions in S. agalactiae and that, under the conditions tested, the Adc/Lmb transporter constitutes the main zinc acquisition system of the bacterium. IMPORTANCE A zinc transporter, composed of three redundant binding proteins (Lmb, AdcA, and AdcAII), was characterized in Streptococcus agalactiae. This system was shown to be essential for bacterial growth and morphology in zinc-restricted environments, including human biological fluids. PMID:27672194

A study on the dynamics of the zraP gene expression profile and its application to the construction of zinc adsorption bacteria.

PubMed

Ravikumar, Sambandam; Yoo, Ik-keun; Lee, Sang Yup; Hong, Soon Ho

2011-11-01

Zinc ion plays essential roles in biological chemistry. Bacteria acquire Zn(2+) from the environment, and cellular concentration levels are controlled by zinc homeostasis systems. In comparison with other homeostatic systems, the ZraSR two-component system was found to be more efficient in responding to exogenous zinc concentrations. To understand the dynamic response of the bacterium ZraSR two-component system with respect to exogenous zinc concentrations, the genetic circuit of the ZraSR system was integrated with a reporter protein. This study was helpful in the construction of an E. coli system that can display selective metal binding peptides on the surface of the cell in response to exogenous zinc. The engineered bacterial system for monitoring exogenous zinc was successfully employed to detect levels of zinc as low as 0.001 mM, which directly activates the expression of chimeric ompC(t)--zinc binding peptide gene to remove zinc by adsorbing a maximum of 163.6 μmol of zinc per gram of dry cell weight. These results indicate that the engineered bacterial strain developed in the present study can sense the specific heavy metal and activates a cell surface display system that acts to remove the metal.

Zinc and redox signaling: perturbations associated with cardiovascular disease and diabetes mellitus.

PubMed

Foster, Meika; Samman, Samir

2010-11-15

Cellular signal transduction pathways are influenced by the zinc and redox status of the cell. Numerous chronic diseases, including cardiovascular disease (CVD) and diabetes mellitus (DM), have been associated with impaired zinc utilization and increased oxidative stress. In humans, mutations in the MT-1A and ZnT8 genes, both of which are involved in the maintenance of zinc homeostasis, have been linked with DM development. Changes in levels of intracellular free zinc may exacerbate oxidative stress in CVD and DM by impacting glutathione homeostasis, nitric oxide signaling, and nuclear factor-kappa B-dependent cellular processes. Zinc ions have been shown to influence insulin and leptin signaling via the phosphoinositide 3′-kinase/Akt pathway, potentially linking an imbalance of zinc at the cellular level to insulin resistance and dyslipidemia. The oxidative modification of cysteine residues in zinc coordination sites in proteins has been implicated in cellular signaling and regulatory pathways. Despite the many interactions between zinc and cellular stress responses, studies investigating the potential therapeutic benefit of zinc supplementation in the prevention and treatment of oxidative stress-related chronic disease in humans are few and inconsistent. Further well-designed randomized controlled trials are needed to determine the effects of zinc supplementation in populations at various stages of CVD and DM progression.

A comprehensive review of the role of zinc in normal prostate function and metabolism; and its implications in prostate cancer☆

PubMed Central

Costello, Leslie C.; Franklin, Renty B.

2016-01-01

The human prostate gland contains extremely high zinc levels; which is due to the specialized zinc-accumulating acinar epithelial of the peripheral zone. These cells evolved for their unique capability to produce and secrete extremely levels of citrate, which is achieved by the high cellular zinc level effects on the cell metabolism. This review highlights the specific functional and metabolic alterations that result from the accumulation of the high zinc levels, especially its effects on mitochondrial citrate metabolism and terminal oxidation. The implications of zinc in the development and progression of prostate cancer are described, which is the most consistent hallmark characteristic of prostate cancer. The requirement for decreased zinc resulting from down regulation of ZIP1 to prevent zinc cytotoxicity in the malignant cells is described as an essential early event in prostate oncogenesis. This provides the basis for the concept that an agent (such as the zinc ionophore, clioquinol) that facilitates zinc uptake and accumulation in ZIP1-deficient prostate tumors cells will markedly inhibit tumor growth. In the current absence of an efficacious chemotherapy for advanced prostate cancer, and for prevention of early development of malignancy; a zinc treatment regimen is a plausible approach that should be pursued. PMID:27132038

Zinc and the modulation of redox homeostasis

PubMed Central

Oteiza, Patricia I.

2012-01-01

Zinc, a redox inactive metal, has been long viewed as a component of the antioxidant network, and growing evidence points to its involvement in redox-regulated signaling. These actions are exerted through several mechanisms based on the unique chemical and functional properties of zinc. Overall, zinc contributes to maintain the cell redox balance through different mechanisms including: i) the regulation of oxidant production and metal-induced oxidative damage; ii) the dynamic association of zinc with sulfur in protein cysteine clusters, from which the metal can be released by nitric oxide, peroxides, oxidized glutathione and other thiol oxidant species; iii) zinc-mediated induction of the zinc-binding protein metallothionein, which releases the metal under oxidative conditions and act per se scavenging oxidants; iv) the involvement of zinc in the regulation of glutathione metabolism and of the overall protein thiol redox status; and v) a direct or indirect regulation of redox signaling. Findings of oxidative stress, altered redox signaling, and associated cell/tissue disfunction in cell and animal models of zinc deficiency, stress the relevant role of zinc in the preservation of cell redox homeostasis. However, while the participation of zinc in antioxidant protection, redox sensing, and redox-regulated signaling is accepted, the involved molecules, targets and mechanisms are still partially known and the subject of active research. PMID:22960578

Blood zinc levels in nursing women from different regions of the West Bank of Palestine.

PubMed

Shawahna, Ramzi; Zyoud, Ahed; Jallad, Donia; Hadwan, Labebah; Ihssan, Neeran; Hilal, Hikmat

2017-07-06

Pregnant and nursing women are at higher risk of zinc deficiency which can have detrimental consequences on health. We assessed blood zinc levels in 72 nursing women from the West Bank of Palestine and investigated the association between sociodemographic variables and blood zinc levels. Blood samples were analyzed for their zinc contents using graphite furnace atomic absorption spectrophotometry. Blood and data collection were performed between July and December 2016. The median blood zinc level was 4.53 mg/L (interquartile range of 0.38 mg/L). In unadjusted analyses, blood zinc levels were higher in nursing women who lived in cities (p-value <.001), had higher household income (p-value <.001), whose husbands had a white collar job (p-value <.05), were nonsmokers (p-value <.05), did not use hair dyes (p-value <.05), and consumed energy beverages (p-value <.001). Multiple linear analysis showed that living in cities and consuming energy beverages remained significantly associated with higher blood zinc levels (p-value <.05). Blood zinc levels were in the range previously reported for similar non-malnourished populations. Nursing women living in cities and those consuming energy beverages tended to have higher blood zinc levels. Urbanized lifestyle might have enhanced blood zinc levels in nursing women.

40 CFR 98.330 - Definition of the source category.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.330 Definition of the source category. The zinc production source category consists of zinc smelters and secondary zinc recycling facilities. ...

40 CFR 98.330 - Definition of the source category.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Zinc Production § 98.330 Definition of the source category. The zinc production source category consists of zinc smelters and secondary zinc recycling facilities. ...

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

PubMed

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight loss in hyperthyroidism.

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.

Thyroid Hormone Upregulates Zinc-α2-glycoprotein Production in the Liver but Not in Adipose Tissue

PubMed Central

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M.

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight loss in hyperthyroidism. PMID:24465683

Is There a Relationship between Zinc and the Peculiar Comorbidities of Down Syndrome?

ERIC Educational Resources Information Center

Romano, Corrado; Pettinato, Rosa; Ragusa, Letizia; Barone, Concetta; Alberti, Antonino; Failla, Pinella

2002-01-01

A comparison was made between a range of clinical and biochemical variables and zinc levels in 120 individuals with Down syndrome. No significant differences were found between the normal-zinc and low-zinc groups, except for IgG4 which was, unexpectedly, significantly decreased in the group with normal zinc levels. (Contains references.)…

Vesicular zinc promotes presynaptic and inhibits postsynaptic long term potentiation of mossy fiber-CA3 synapse

PubMed Central

Pan, Enhui; Zhang, Xiao-an; Huang, Zhen; Krezel, Artur; Zhao, Min; Tin-berg, Christine E.; Lippard, Stephen J.; McNamara, James O.

2011-01-01

The presence of zinc in glutamatergic synaptic vesicles of excitatory neurons of mammalian cerebral cortex suggests that zinc might regulate plasticity of synapses formed by these neurons. Long term potentiation (LTP) is a form of synaptic plasticity that may underlie learning and memory. We tested the hypothesis that zinc within vesicles of mossy fibers (mf) contributes to mf-LTP, a classical form of presynaptic LTP. We synthesized an extracellular zinc chelator with selectivity and kinetic properties suitable for study of the large transient of zinc in the synaptic cleft induced by mf stimulation. We found that vesicular zinc is required for presynaptic mf-LTP. Unexpectedly, vesicular zinc also inhibits a novel form of postsynaptic mf-LTP. Because the mf-CA3 synapse provides a major source of excitatory input to the hippocampus, regulating its efficacy by these dual actions of vesicular zinc is critical to proper function of hippocampal circuitry in health and disease. PMID:21943607

Metallic Zinc Exhibits Optimal Biocompatibility for Bioabsorbable Endovascular Stents

PubMed Central

Bowen, Patrick K.; Guillory, Roger J.; Shearier, Emily R.; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

2015-01-01

Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5 months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5 months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells. PMID:26249616

Selective Sensitization of Zinc Finger Protein Oxidation by Reactive Oxygen Species through Arsenic Binding*

PubMed Central

Zhou, Xixi; Cooper, Karen L.; Sun, Xi; Liu, Ke J.; Hudson, Laurie G.

2015-01-01

Cysteine oxidation induced by reactive oxygen species (ROS) on redox-sensitive targets such as zinc finger proteins plays a critical role in redox signaling and subsequent biological outcomes. We found that arsenic exposure led to oxidation of certain zinc finger proteins based on arsenic interaction with zinc finger motifs. Analysis of zinc finger proteins isolated from arsenic-exposed cells and zinc finger peptides by mass spectrometry demonstrated preferential oxidation of C3H1 and C4 zinc finger configurations. C2H2 zinc finger proteins that do not bind arsenic were not oxidized by arsenic-generated ROS in the cellular environment. The findings suggest that selectivity in arsenic binding to zinc fingers with three or more cysteines defines the target proteins for oxidation by ROS. This represents a novel mechanism of selective protein oxidation and demonstrates how an environmental factor may sensitize certain target proteins for oxidation, thus altering the oxidation profile and redox regulation. PMID:26063799

New Insights into the Role of Zinc Acquisition and Zinc Tolerance in Group A Streptococcal Infection.

PubMed

Ong, Cheryl-Lynn Y; Berking, Olga; Walker, Mark J; McEwan, Alastair G

2018-06-01

Zinc plays an important role in host innate immune function. However, the innate immune system also utilizes zinc starvation ("nutritional immunity") to combat infections. Here, we investigate the role of zinc import and export in the protection of Streptococcus pyogenes (group A Streptococcus ; GAS), a Gram-positive bacterial pathogen responsible for a wide spectrum of human diseases, against challenge from host innate immune defense. In order to determine the role of GAS zinc import and export during infection, we utilized zinc import (Δ adcA Δ adcAII ) and export (Δ czcD ) deletion mutants in competition with the wild type in both in vitro and in vivo virulence models. We demonstrate that nutritional immunity is deployed extracellularly, while zinc toxicity is utilized upon phagocytosis of GAS by neutrophils. We also show that lysosomes and azurophilic granules in neutrophils contain zinc stores for use against intracellular pathogens. Copyright © 2018 American Society for Microbiology.

Particulate nanocomposite from oyster (Crassostrea rivularis) hydrolysates via zinc chelation improves zinc solubility and peptide activity.

PubMed

Zhang, Ziran; Zhou, Feibai; Liu, Xiaoling; Zhao, Mouming

2018-08-30

An oyster protein hydrolysates-zinc complex (OPH-Zn) was prepared and investigated to improve zinc bioaccessibility. Zinc ions chelating with oyster protein hydrolysates (OPH) cause intramolecular and intermolecular folding and aggregation, homogeneously forming the OPH-Zn complex as nanoclusters with a Z-average at 89.28 nm (PDI: 0.16 ± 0.02). The primary sites of zinc-binding in OPH were carboxyl groups, carbonyl groups, and amino groups, and they were related to the high number of charged amino acid residues. Furthermore, formation of the OPH-Zn complex could significantly enhance zinc solubility both under specific pH conditions as well as during simulated gastrointestinal digestion, compared to the commonly used ZnSO 4 . Additionally, after digestion, either preserved or enhanced antioxidant activity of OPH was found when chelated with zinc. These results indicated that the OPH-Zn complex could be a potential functional ingredient with improved antioxidant bioactivity and zinc bioaccessibility. Copyright © 2018. Published by Elsevier Ltd.

Aqueous rechargeable zinc/sodium vanadate batteries with enhanced performance from simultaneous insertion of dual carriers.

PubMed

Wan, Fang; Zhang, Linlin; Dai, Xi; Wang, Xinyu; Niu, Zhiqiang; Chen, Jun

2018-04-25

Rechargeable aqueous zinc-ion batteries are promising energy storage devices due to their high safety and low cost. However, they remain in their infancy because of the limited choice of positive electrodes with high capacity and satisfactory cycling performance. Furthermore, their energy storage mechanisms are not well established yet. Here we report a highly reversible zinc/sodium vanadate system, where sodium vanadate hydrate nanobelts serve as positive electrode and zinc sulfate aqueous solution with sodium sulfate additive is used as electrolyte. Different from conventional energy release/storage in zinc-ion batteries with only zinc-ion insertion/extraction, zinc/sodium vanadate hydrate batteries possess a simultaneous proton, and zinc-ion insertion/extraction process that is mainly responsible for their excellent performance, such as a high reversible capacity of 380 mAh g -1 and capacity retention of 82% over 1000 cycles. Moreover, the quasi-solid-state zinc/sodium vanadate hydrate battery is also a good candidate for flexible energy storage device.

The zinc spark is an inorganic signature of human egg activation.

PubMed

Duncan, Francesca E; Que, Emily L; Zhang, Nan; Feinberg, Eve C; O'Halloran, Thomas V; Woodruff, Teresa K

2016-04-26

Egg activation refers to events required for transition of a gamete into an embryo, including establishment of the polyspermy block, completion of meiosis, entry into mitosis, selective recruitment and degradation of maternal mRNA, and pronuclear development. Here we show that zinc fluxes accompany human egg activation. We monitored calcium and zinc dynamics in individual human eggs using selective fluorophores following activation with calcium-ionomycin, ionomycin, or hPLCζ cRNA microinjection. These egg activation methods, as expected, induced rises in intracellular calcium levels and also triggered the coordinated release of zinc into the extracellular space in a prominent "zinc spark." The ability of the gamete to mount a zinc spark response was meiotic-stage dependent. Moreover, chelation of intracellular zinc alone was sufficient to induce cell cycle resumption and transition of a meiotic cell into a mitotic one. Together, these results demonstrate critical functions for zinc dynamics and establish the zinc spark as an extracellular marker of early human development.

The Zinc-Schiff Base-Novicidin Complex as a Potential Prostate Cancer Therapy

PubMed Central

Milosavljevic, Vedran; Haddad, Yazan; Merlos Rodrigo, Miguel Angel; Moulick, Amitava; Polanska, Hana; Hynek, David; Heger, Zbynek; Kopel, Pavel; Adam, Vojtech

2016-01-01

Prostate cancer cells control energy metabolism by chelating intracellular zinc. Thus, zinc delivery has been a popular therapeutic approach for prostate cancer. Here, we propose the use of the membrane-penetrating peptide Novicidin connected to zinc-Schiff base as a carrier vehicle for the delivery of zinc to prostate cells. Mass spectrometry, electrochemistry and spectrophotometry confirmed the formation/stability of this complex and provided insight regarding the availability of zinc for complex interactions. This delivery system showed minor toxicity in normal PNT1A cells and high potency towards PC3 tumor cells. The complex preferentially penetrated PC3 tumor cells in contrast to confinement to the membranes of PNT1A. Furthermore, zinc uptake was confirmed in both cell lines. Molecular analysis was used to confirm the activation of zinc stress (e.g., ZnT-1) and apoptosis (e.g., CASP-1). Our results strongly suggest that the zinc-Schiff base-Novicidin complex has great potential as a novel anticancer drug. PMID:27727290

The zinc spark is an inorganic signature of human egg activation

PubMed Central

Duncan, Francesca E.; Que, Emily L.; Zhang, Nan; Feinberg, Eve C.; O’Halloran, Thomas V.; Woodruff, Teresa K.

2016-01-01

Egg activation refers to events required for transition of a gamete into an embryo, including establishment of the polyspermy block, completion of meiosis, entry into mitosis, selective recruitment and degradation of maternal mRNA, and pronuclear development. Here we show that zinc fluxes accompany human egg activation. We monitored calcium and zinc dynamics in individual human eggs using selective fluorophores following activation with calcium-ionomycin, ionomycin, or hPLCζ cRNA microinjection. These egg activation methods, as expected, induced rises in intracellular calcium levels and also triggered the coordinated release of zinc into the extracellular space in a prominent “zinc spark.” The ability of the gamete to mount a zinc spark response was meiotic-stage dependent. Moreover, chelation of intracellular zinc alone was sufficient to induce cell cycle resumption and transition of a meiotic cell into a mitotic one. Together, these results demonstrate critical functions for zinc dynamics and establish the zinc spark as an extracellular marker of early human development. PMID:27113677

Dietary intervention strategies to enhance zinc nutrition: Promotion and support of breastfeeding for infants and young children

PubMed Central

Brown, Kenneth H.; Engle-Stone, Reina; Krebs, Nancy F.; Peerson, Janet M.

2017-01-01

Breastmilk is the only dietary source of zinc for exclusively breastfed young infants, and it remains a potentially important source of zinc for older infants and young children who continue breastfeeding beyond early infancy. Therefore, we examined available information on breastmilk zinc concentration and total milk consumption to develop estimates of the amount of zinc transferred in breastmilk to children of different ages. Breastmilk zinc concentration declines rapidly during the first few months postpartum and more slowly thereafter. Breastmilk supplies all of the theoretical zinc needs for at least the first several months of life, although the period during which breastmilk alone remains sufficient is uncertain. Breastmilk continues to provide more than half of children’s estimated zinc requirements after the introduction of complementary foods, even into the second year of life. Public health programs to promote and support breastfeeding should be included among the strategies to ensure adequate zinc status of young children. PMID:19472605

Modulation of neuronal signal transduction and memory formation by synaptic zinc.

PubMed

Sindreu, Carlos; Storm, Daniel R

2011-01-01

The physiological role of synaptic zinc has remained largely enigmatic since its initial detection in hippocampal mossy fibers over 50 years ago. The past few years have witnessed a number of studies highlighting the ability of zinc ions to regulate ion channels and intracellular signaling pathways implicated in neuroplasticity, and others that shed some light on the elusive role of synaptic zinc in learning and memory. Recent behavioral studies using knock-out mice for the synapse-specific zinc transporter ZnT-3 indicate that vesicular zinc is required for the formation of memories dependent on the hippocampus and the amygdala, two brain centers that are prominently innervated by zinc-rich fibers. A common theme emerging from this research is the activity-dependent regulation of the Erk1/2 mitogen-activated-protein kinase pathway by synaptic zinc through diverse mechanisms in neurons. Here we discuss current knowledge on how synaptic zinc may play a role in cognition through its impact on neuronal signaling.

Modulation of Neuronal Signal Transduction and Memory Formation by Synaptic Zinc

PubMed Central

Sindreu, Carlos; Storm, Daniel R.

2011-01-01

The physiological role of synaptic zinc has remained largely enigmatic since its initial detection in hippocampal mossy fibers over 50 years ago. The past few years have witnessed a number of studies highlighting the ability of zinc ions to regulate ion channels and intracellular signaling pathways implicated in neuroplasticity, and others that shed some light on the elusive role of synaptic zinc in learning and memory. Recent behavioral studies using knock-out mice for the synapse-specific zinc transporter ZnT-3 indicate that vesicular zinc is required for the formation of memories dependent on the hippocampus and the amygdala, two brain centers that are prominently innervated by zinc-rich fibers. A common theme emerging from this research is the activity-dependent regulation of the Erk1/2 mitogen-activated-protein kinase pathway by synaptic zinc through diverse mechanisms in neurons. Here we discuss current knowledge on how synaptic zinc may play a role in cognition through its impact on neuronal signaling. PMID:22084630

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.

Measurement of Menadione in Urine by HPLC

PubMed Central

Rajabi, Ala Al; Peterson, James; Choi, Sang Woon; Suttie, John; Barakat, Susan; Booth, Sarah L

2010-01-01

Menadione is a metabolite of vitamin K that is excreted in urine. A high performance liquid chromatography (HPLC) method using a C30 column, post-column zinc reduction and fluorescence detection was developed to measure urinary menadione. The mobile phase was composed of 95% methanol with 0.55% aqueous solution and 5% DI H2O. Menaquinone-2 (MK-2) was used as an internal standard. The standard calibration curve was linear with a correlation coefficient (R2) of 0.999 for both menadione and MK-2. The lower limit of quantification (LLOQ) was 0.3 pmole menadione/mL urine. Sample preparation involved hydrolysis of menadiol conjugates and oxidizing the released menadiol to menadione. Using this method, urinary menadione was shown to increase in response to 3 years of phylloquinone supplementation. This HPLC method is a sensitive and reproducible way to detect menadione in urine. Research support: USDA ARS Cooperative Agreement 58-1950-7-707. PMID:20719580

InGaAsP-based uni-travelling carrier photodiode structure grown by solid source molecular beam epitaxy.

PubMed

Natrella, Michele; Rouvalis, Efthymios; Liu, Chin-Pang; Liu, Huiyun; Renaud, Cyril C; Seeds, Alwyn J

2012-08-13

We report the first InGaAsP-based uni-travelling carrier photodiode structure grown by Solid Source Molecular Beam Epitaxy; the material contains layers of InGaAsP as thick as 300 nm and a 120 nm thick InGaAs absorber. Large area vertically illuminated test devices have been fabricated and characterised; the devices exhibited 0.1 A/W responsivity at 1550 nm, 12.5 GHz -3 dB bandwidth and -5.8 dBm output power at 10 GHz for a photocurrent of 4.8 mA. The use of Solid Source Molecular Beam Epitaxy enables the major issue associated with the unintentional diffusion of zinc in Metal Organic Vapour Phase Epitaxy to be overcome and gives the benefit of the superior control provided by MBE growth techniques without the costs and the risks of handling toxic gases of Gas Source Molecular Beam Epitaxy.

Optical properties of zinc lead tellurite glasses

NASA Astrophysics Data System (ADS)

Alazoumi, Salah Hassan; Aziz, Sidek Abdul; El-Mallawany, R.; Aliyu, Umar Sa'ad; Kamari, Halimah Mohamed; Zaid, Mohd Hafiz Mohd Mohd; Matori, Khamirul Amin; Ushah, Abdulbaset

2018-06-01

Tellurite glass systems in the form of [ZnO]x [(TeO2)0.7-(PbO)0.3]1-x with x = 0.15, 0.17, 0.20, 0.22 and 0.25 mol% were prepared using the melt quenching technique. XRD of the prepared samples have been measured for all samples. Both FTIR (280-4000 cm-1) and UV-Vis (200-800 nm) spectra have been measured. Optical band gap and refractive index were calculated for every glass sample. Density of glass, molar volume and oxygen packing density (OPD) were obtained. Values of the direct, indirect band gap ranged were found in the range 3.41-3.94 eV and 2.40-2.63 eV with increasing of ZnO concentration. Refractive index 2.58 and dielectric constant 6.66 were heigh at 17 ZnO mol% concentration. Molar polarizability, metallization criterion, polaron radius have been calculated for every glass composition.

Bacterial toxicity comparison between nano- and micro-scaled oxide particles.

PubMed

Jiang, Wei; Mashayekhi, Hamid; Xing, Baoshan

2009-05-01

Toxicity of nano-scaled aluminum, silicon, titanium and zinc oxides to bacteria (Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens) was examined and compared to that of their respective bulk (micro-scaled) counterparts. All nanoparticles but titanium oxide showed higher toxicity (at 20 mg/L) than their bulk counterparts. Toxicity of released metal ions was differentiated from that of the oxide particles. ZnO was the most toxic among the three nanoparticles, causing 100% mortality to the three tested bacteria. Al(2)O(3) nanoparticles had a mortality rate of 57% to B. subtilis, 36% to E. coli, and 70% to P. fluorescens. SiO(2) nanoparticles killed 40% of B. subtilis, 58% of E. coli, and 70% of P. fluorescens. TEM images showed attachment of nanoparticles to the bacteria, suggesting that the toxicity was affected by bacterial attachment. Bacterial responses to nanoparticles were different from their bulk counterparts; hence nanoparticle toxicity mechanisms need to be studied thoroughly.

Zinc-The key to preventing corrosion

USGS Publications Warehouse

Kropschot, S.J.; Doebrich, Jeff L.

2011-01-01

Centuries before it was identified as an element, zinc was used to make brass (an alloy of zinc and copper) and for medicinal purposes. Metallic zinc and zinc oxide were produced in India sometime between the 11th and 14th centuries and in China in the 17th century, although the discovery of pure metallic zinc is credited to the German chemist Andreas Marggraf, who isolated the element in 1746. Refined zinc metal is bluish-white when freshly cast; it is hard and brittle at most temperatures and has relatively low melting and boiling points. Zinc alloys readily with other metals and is chemically active. On exposure to air, it develops a thin gray oxide film (patina), which inhibits deeper oxidation (corrosion) of the metal. The metal's resistance to corrosion is an important characteristic in its use.

Effect of pulsed electric fields upon accumulation of zinc in Saccharomyces cerevisiae.

PubMed

Pankiewicz, Urszula; Jamroz, Jerzy

2011-06-01

Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 microns pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 microgram/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

Alterations of zinc homeostasis in response to Cryptococcus neoformans in a murine macrophage cell line.

PubMed

Dos Santos, Francine Melise; Piffer, Alícia Corbellini; Schneider, Rafael de Oliveira; Ribeiro, Nicole Sartori; Garcia, Ane Wichine Acosta; Schrank, Augusto; Kmetzsch, Lívia; Vainstein, Marilene Henning; Staats, Charley Christian

2017-05-01

To evaluate alterations of zinc homeostasis in macrophages exposed to Cryptococcus neoformans. Materials & methods: Using a fluorescent zinc probe-based flow cytometry and atomic absorption spectrometry, zinc levels were evaluated in J774.A1 cell lines exposed to C. neoformans H99 cells. The transcription profile of macrophage zinc related homeostasis genes - metallothioneins and zinc transporters (ZnTs) of the SLC30 and SLC39 (Zrt-Irt-protein) families - was analyzed by quantitative PCR. Macrophage intracellular labile zinc levels decreased following exposure to C. neoformans. A significant decrease in transcription levels was detected in specific ZnTs from both the Zrt-Irt-protein and ZnT families, especially 24 h after infection. These findings suggest that macrophages may exhibit zinc depletion in response to C. neoformans infection.

Zinc oxide-based sorbents and processes for preparing and using same

DOEpatents

Gangwal, Santosh Kumar; Turk, Brian Scott; Gupta, Raghubir Prasad

2005-10-04

Zinc oxide-based sorbents, and processes for preparing and using them are provided, wherein the sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents contain an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl.sub.2 O.sub.4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, containing a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

Zinc-oxide-based sorbents and processes for preparing and using same

DOEpatents

Gangwal, Santosh Kumar; Turk, Brian Scott; Gupta, Raghubir Prasael

2010-03-23

Zinc oxide-based sorbents, and processes for preparing and using them are provided. The sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents comprise an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl.sub.2O.sub.4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, comprising a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

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

Zinc triggers microglial activation.

PubMed

Kauppinen, Tiina M; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A

2008-05-28

Microglia are resident immune cells of the CNS. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, "ameboid" morphology and release matrix metalloproteinases, reactive oxygen species, and other proinflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here, we show that zinc directly triggers microglial activation. Microglia transfected with a nuclear factor-kappaB (NF-kappaB) reporter gene showed a severalfold increase in NF-kappaB activity in response to 30 microm zinc. Cultured mouse microglia exposed to 15-30 microm zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-kappaB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-kappaB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders.

Subacute Zinc Administration and L-NAME Caused an Increase of NO, Zinc, Lipoperoxidation, and Caspase-3 during a Cerebral Hypoxia-Ischemia Process in the Rat

PubMed Central

Blanco-Alvarez, Victor Manuel; Lopez-Moreno, Patricia; Soto-Rodriguez, Guadalupe; Martinez-Fong, Daniel; Rubio, Hector; Gonzalez-Barrios, Juan Antonio; Piña-Leyva, Celia; Torres-Soto, Maricela; Gomez-Villalobos, María de Jesus; Hernandez-Baltazar, Daniel; Eguibar, José Ramon; Ugarte, Araceli; Cebada, Jorge

2013-01-01

Zinc or L-NAME administration has been shown to be protector agents, decreasing oxidative stress and cell death. However, the treatment with zinc and L-NAME by intraperitoneal injection has not been studied. The aim of our work was to study the effect of zinc and L-NAME administration on nitrosative stress and cell death. Male Wistar rats were treated with ZnCl2 (2.5 mg/kg each 24 h, for 4 days) and N-ω-nitro-L-arginine-methyl ester (L-NAME, 10 mg/kg) on the day 5 (1 hour before a common carotid-artery occlusion (CCAO)). The temporoparietal cortex and hippocampus were dissected, and zinc, nitrites, and lipoperoxidation were assayed at different times. Cell death was assayed by histopathology using hematoxylin-eosin staining and caspase-3 active by immunostaining. The subacute administration of zinc before CCAO decreases the levels of zinc, nitrites, lipoperoxidation, and cell death in the late phase of the ischemia. L-NAME administration in the rats treated with zinc showed an increase of zinc levels in the early phase and increase of zinc, nitrites, and lipoperoxidation levels, cell death by necrosis, and the apoptosis in the late phase. These results suggest that the use of these two therapeutic strategies increased the injury caused by the CCAO, unlike the alone administration of zinc. PMID:23997853

LiZIP3 is a cellular zinc transporter that mediates the tightly regulated import of zinc in Leishmania infantum parasites

PubMed Central

Carvalho, Sandra; da Silva, Rosa Barreira; Shawki, Ali; Castro, Helena; Lamy, Márcia; Eide, David; Costa, Vítor; Mackenzie, Bryan; Tomás, Ana M.

2016-01-01

Summary Cellular zinc homeostasis ensures that the intracellular concentration of this element is kept within limits that enable its participation in critical physiological processes without exerting toxic effects. We report here the identification and characterization of the first mediator of zinc homeostasis in Leishmania infantum, LiZIP3, a member of the ZIP family of divalent metal-ion transporters. The zinc transporter activity of LiZIP3 was first disclosed by its capacity to rescue the growth of Saccharomyces cerevisiae strains deficient in zinc acquisition. Subsequent expression of LiZIP3 in Xenopus laevis oocytes was shown to stimulate the uptake of a broad range of metal ions, among which Zn2+ was the preferred LiZIP3 substrate (K0.5 ≈ 0.1 μM). Evidence that LiZIP3 functions as a zinc importer in L. infantum came from the observations that the protein locates to the cell membrane and that its overexpression leads to augmented zinc internalization. Importantly, expression and cell-surface location of LiZIP3 are lost when parasites face high zinc bioavailability. LiZIP3 decline in response to zinc is regulated at the mRNA level in a process involving (a) short-lived protein(s). Collectively, our data reveal that LiZIP3 enables L. infantum to acquire zinc in a highly regulated manner, hence contributing to zinc homeostasis. PMID:25644708

Zinc Status of Vegetarians during Pregnancy: A Systematic Review of Observational Studies and Meta-Analysis of Zinc Intake.

PubMed

Foster, Meika; Herulah, Ursula Nirmala; Prasad, Ashlini; Petocz, Peter; Samman, Samir

2015-06-05

Pregnant women are vulnerable to a low zinc status due to the additional zinc demands associated with pregnancy and foetal development. The present systematic review explores the relationship between habitual vegetarian diets and dietary zinc intake/status during pregnancy. The association between vegetarian diets and functional pregnancy outcome also is considered. A literature search was conducted of MEDLINE; PubMed; Embase; the Cochrane Library; Web of Science; and Scopus electronic databases up to September 2014. Six English-language observational studies qualified for inclusion in the systematic review. A meta-analysis was conducted that compared the dietary zinc intake of pregnant vegetarian and non-vegetarian (NV) groups; the zinc intake of vegetarians was found to be lower than that of NV (-1.38 ± 0.35 mg/day; p < 0.001); and the exclusion of low meat eaters from the analysis revealed a greater difference (-1.53 ± 0.44 mg/day; p = 0.001). Neither vegetarian nor NV groups met the recommended dietary allowance (RDA) for zinc. In a qualitative synthesis; no differences were found between groups in serum/plasma zinc or in functional outcomes associated with pregnancy. In conclusion; pregnant vegetarian women have lower zinc intakes than NV control populations and both groups consume lower than recommended amounts. Further information is needed to determine whether physiologic adaptations in zinc metabolism are sufficient to meet maternal and foetal requirements during pregnancy on a low zinc diet.

Zinc Status of Vegetarians during Pregnancy: A Systematic Review of Observational Studies and Meta-Analysis of Zinc Intake

PubMed Central

Foster, Meika; Herulah, Ursula Nirmala; Prasad, Ashlini; Petocz, Peter; Samman, Samir

2015-01-01

Pregnant women are vulnerable to a low zinc status due to the additional zinc demands associated with pregnancy and foetal development. The present systematic review explores the relationship between habitual vegetarian diets and dietary zinc intake/status during pregnancy. The association between vegetarian diets and functional pregnancy outcome also is considered. A literature search was conducted of MEDLINE; PubMed; Embase; the Cochrane Library; Web of Science; and Scopus electronic databases up to September 2014. Six English-language observational studies qualified for inclusion in the systematic review. A meta-analysis was conducted that compared the dietary zinc intake of pregnant vegetarian and non-vegetarian (NV) groups; the zinc intake of vegetarians was found to be lower than that of NV (−1.38 ± 0.35 mg/day; p < 0.001); and the exclusion of low meat eaters from the analysis revealed a greater difference (−1.53 ± 0.44 mg/day; p = 0.001). Neither vegetarian nor NV groups met the recommended dietary allowance (RDA) for zinc. In a qualitative synthesis; no differences were found between groups in serum/plasma zinc or in functional outcomes associated with pregnancy. In conclusion; pregnant vegetarian women have lower zinc intakes than NV control populations and both groups consume lower than recommended amounts. Further information is needed to determine whether physiologic adaptations in zinc metabolism are sufficient to meet maternal and foetal requirements during pregnancy on a low zinc diet. PMID:26056918

Zinc in Pancreatic Islet Biology, Insulin Sensitivity, and Diabetes

PubMed Central

Maret, Wolfgang

2017-01-01

About 20 chemical elements are nutritionally essential for humans with defined molecular functions. Several essential and nonessential biometals are either functional nutrients with antidiabetic actions or can be diabetogenic. A key question remains whether changes in the metabolism of biometals and biominerals are a consequence of diabetes or are involved in its etiology. Exploration of the roles of zinc (Zn) in this regard is most revealing because 80 years of scientific discoveries link zinc and diabetes. In pancreatic β- and α-cells, zinc has specific functions in the biochemistry of insulin and glucagon. When zinc ions are secreted during vesicular exocytosis, they have autocrine, paracrine, and endocrine roles. The membrane protein ZnT8 transports zinc ions into the insulin and glucagon granules. ZnT8 has a risk allele that predisposes the majority of humans to developing diabetes. In target tissues, increased availability of zinc enhances the insulin response by inhibiting protein tyrosine phosphatase 1B, which controls the phosphorylation state of the insulin receptor and hence downstream signalling. Inherited diseases of zinc metabolism, environmental exposures that interfere with the control of cellular zinc homeostasis, and nutritional or conditioned zinc deficiency influence the patho-biochemistry of diabetes. Accepting the view that zinc is one of the many factors in multiple gene-environment interactions that cause the functional demise of β-cells generates an immense potential for treating and perhaps preventing diabetes. Personalized nutrition, bioactive food, and pharmaceuticals targeting the control of cellular zinc in precision medicine are among the possible interventions. PMID:28401081

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.

[Assessment of efficiency of dietotherapy with addition of a vitamin-mineral complex in patients with diabetes mellitus type 2].

PubMed

Lapik, I A; Sokol'nikov, A A; Sharafetdinov, Kh Kh; Sentsova, T B; Plotnikova, O A

2014-01-01

The influence of diet inclusion of vitamin and mineral complex (VMC), potassium and magnesium in the form of asparaginate on micronutrient status, body composition and biochemical parameters in patients with diabetes mellitus type 2 (DM2) has been investigated. 120 female patients with DM2 and obesity of I-III degree (mean age - 58 +/- 6 years) have been included in the study. The patients were divided into two groups: main group (n = 60) and control group (n = 60). For 3 weeks patients of both groups received a low-calorie diet (1600 kcal/day). Patients of the main group received VMC, providing an additional intake of vitamins C and E (100-120% RDA), beta-carotene (40% RDA), nicotinamide (38% RDA), pantothenic acid and biotin (60% RDA), vitamins B12, B2 and folic acid (75-83% RDA), vitamins B1 and B6 (160-300% RDA), zinc (100% RDA) and chromium (400% RDA), and also received magnesium (17.7% RDA) and potassium (9.4% RDA) in the form of asparaginate. Body composition, biochemical parameters and micronutrient status (blood serum level of vitamins C, D, B6, B12, folate, potassium, calcium, magnesium, zinc, phosphorus) were evaluated in all patients before and after the 3-week course of diet therapy. After the low-calorie diet therapy average body weight reduction was 4.2 +/- 0.2 kg in the main group, and 4.4 +/- 0.1 kg in the control group, without statistically significant differences between groups. Statistically significant decrease of total cholesterol, triglycerides, and glucose concentration in blood serum was registered in both groups. It should be noted that in the control group glycemia decreased on 1.2 +/- 0.1 mmol/l, while the main group showed a decrease on 1.8 +/- 0.1 (p < 0.05) to normal values (5.4 +/- 0.1 mmol/l). Initial assessment of vitamin and mineral status revealed that most patients were optimal supplied with vitamins and minerals. After the dietotherapy significant increase of vitamin C, 25-hydroxyvitamin D, vitamin B6, folate, vitamin B12, potassium, magnesium, calcium, zinc and phosphorus concentration in blood serum was observed in patients receiving VMC. While in the control group statistically significant decrease of vitamin C, magnesium, zinc and phosphorus concentration in blood serum after the treatment was revealed. The obtained data shows the necessity of addition of the vitamin-mineral complex to the diet of patients with DM2 and obesity.

High performance zinc anode for battery applications

NASA Technical Reports Server (NTRS)

Casey, John E., Jr. (Inventor)

1998-01-01

An improved zinc anode for use in a high density rechargeable alkaline battery is disclosed. A process for making the zinc electrode comprises electrolytic loading of the zinc active material from a slightly acidic zinc nitrate solution into a substrate of nickel, copper or silver. The substrate comprises a sintered plaque having very fine pores, a high surface area, and 80-85 percent total initial porosity. The residual porosity after zinc loading is approximately 25-30%. The electrode of the present invention exhibits reduced zinc mobility, shape change and distortion, and demonstrates reduced dendrite buildup cycling of the battery. The disclosed battery is useful for applications requiring high energy density and multiple charge capability.

Impact of Testosterone, Zinc, Calcium and Magnesium Concentrations on Sperm Parameters in Subfertile Men

NASA Astrophysics Data System (ADS)

Aydemir, Birsen; Kiziler, Ali Riza; Onaran, Ilhan; Alici, Bülent; Özkara, Hamdi; Akyolcu, Mehmet Can

2007-04-01

To investigate the impact of testosterone, zinc, calcium and magnesium concentrations in serum and seminal plasma on sperm parameters. There were significant decrease in sperm parameters, serum and seminal plasma zinc levels in subfertile males. It indicates zinc has a essential role in male infertility; the determination the level of zinc during infertility investigation is recommended.

Over-expression of ZnT7 increases insulin synthesis and secretion in pancreatic beta-cells by promoting insulin gene transcription

USDA-ARS?s Scientific Manuscript database

The mechanism by which zinc regulates insulin synthesis and secretion in pancreatic beta-cells is still unclear. Cellular zinc homeostasis is largely maintained by zinc transporters and intracellular zinc binding proteins. In this study, we demonstrated that zinc transporter 7 (ZnT7, Slc30a7) was co...

Expression of zinc transporter ZnT7 in mouse superior cervical ganglion

USDA-ARS?s Scientific Manuscript database

The superior cervical ganglion (SCG) neurons contain a considerable amount of zinc ions, but little is known about zinc homeostasis in the SCG. It is known that zinc transporter 7 (ZnT7, Slc30a7), a member of the Slc30 ZnT family, is involved in mobilizing zinc ions from the cytoplasm into the Golgi...

Binding Site Configurations Probe the Structure and Dynamics of the Zinc Finger of NEMO (NF-κB Essential Modulator).

PubMed

Godwin, Ryan C; Melvin, Ryan L; Gmeiner, William H; Salsbury, Freddie R

2017-01-31

Zinc-finger proteins are regulators of critical signaling pathways for various cellular functions, including apoptosis and oncogenesis. Here, we investigate how binding site protonation states and zinc coordination influence protein structure, dynamics, and ultimately function, as these pivotal regulatory proteins are increasingly important for protein engineering and therapeutic discovery. To better understand the thermodynamics and dynamics of the zinc finger of NEMO (NF-κB essential modulator), as well as the role of zinc, we present results of 20 μs molecular dynamics trajectories, 5 μs for each of four active site configurations. Consistent with experimental evidence, the zinc ion is essential for mechanical stabilization of the functional, folded conformation. Hydrogen bond motifs are unique for deprotonated configurations yet overlap in protonated cases. Correlated motions and principal component analysis corroborate the similarity of the protonated configurations and highlight unique relationships of the zinc-bound configuration. We hypothesize a potential mechanism for zinc binding from results of the thiol configurations. The deprotonated, zinc-bound configuration alone predominantly maintains its tertiary structure throughout all 5 μs and alludes rare conformations potentially important for (im)proper zinc-finger-related protein-protein or protein-DNA interactions.

Response of extracellular zinc in the ventral hippocampus against novelty stress.

PubMed

Takeda, Atsushi; Sakurada, Naomi; Kanno, Shingo; Minami, Akira; Oku, Naoto

2006-10-01

An extensive neuronal activity takes place in the hippocampus during exploratory behavior. However, the role of hippocampal zinc in exploratory behavior is poorly understood. To analyze the response of extracellular zinc in the hippocampus against novelty stress, rats were placed for 50 min in a novel environment once a day for 8 days. Extracellular glutamate in the hippocampus was increased during exploratory behavior on day 1, whereas extracellular zinc was decreased. The same phenomenon was observed during exploratory behavior on day 2 and extracellular zinc had returned to the basal level during exploratory behavior on day 8. To examine the significance of the decrease in extracellular zinc in exploratory activity, exploratory behavior was observed during perfusion with 1 mm CaEDTA, a membrane-impermeable zinc chelator. Locomotor activity in the novel environment was decreased by perfusion with CaEDTA. The decrease in extracellular zinc and the increase in extracellular glutamate in exploratory period were abolished by perfusion with CaEDTA. These results suggest that zinc uptake by hippocampal cells is linked to exploratory activity and is required for the activation of the glutamatergic neurotransmitter system. The zinc uptake may be involved in the response to painless psychological stress or in the cognitive processes.

The Relationship between Serum Zinc Level and Heart Failure: A Meta-Analysis

PubMed Central

Yu, Xuefang; Huang, Lei; Zhao, Jinyan; Wang, Zhuoqun; Yao, Wei; Wu, Xianming; Huang, Jingjing

2018-01-01

Zinc is essential for the maintenance of normal cellular structure and functions. Zinc dyshomeostasis can lead to many diseases, such as cardiovascular disease. However, there are conflicting reports on the relationship between serum zinc levels and heart failure (HF). The purpose of the present study is to explore the relationship between serum zinc levels and HF by using a meta-analysis approach. PubMed, Web of Science, and OVID databases were searched for reports on the association between serum zinc levels and HF until June 2016. 12 reports with 1453 subjects from 27 case-control studies were chosen for the meta-analysis. Overall, the pooled analysis indicated that patients with HF had lower zinc levels than the control subjects. Further subgroup analysis stratified by different geographic locations also showed that HF patients had lower zinc levels than the control subjects. In addition, subgroup analysis stratified by HF subgroups found that patients with idiopathic dilated cardiomyopathy (IDCM) had lower zinc levels than the control subjects, except for patients with ischemic cardiomyopathy (ICM). In conclusion, the results of the meta-analysis indicate that there is a significant association between low serum zinc levels and HF. PMID:29682528

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.

Zinc stress induces copper depletion in Acinetobacter baumannii.

PubMed

Hassan, Karl A; Pederick, Victoria G; Elbourne, Liam D H; Paulsen, Ian T; Paton, James C; McDevitt, Christopher A; Eijkelkamp, Bart A

2017-03-11

The first row transition metal ions zinc and copper are essential to the survival of many organisms, although in excess these ions are associated with significant toxicity. Here, we examined the impact of zinc and copper stress on Acinetobacter baumannii, a common opportunistic pathogen. We show that extracellular zinc stress induces a copper-specific depletion phenotype in A. baumannii ATCC 17978. Supplementation with copper not only fails to rescue this phenotype, but further exacerbates the copper depletion. Extensive analysis of the A. baumannii ATCC 17978 genome identified 13 putative zinc/copper resistance efflux pumps. Transcriptional analyses show that four of these transporters are responsive to zinc stress, five to copper stress and seven to the combination of zinc and copper stress, thereby revealing a likely foundation for the zinc-induced copper starvation in A. baumannii. In addition, we show that zinc and copper play crucial roles in management of oxidative stress and the membrane composition of A. baumannii. Further, we reveal that zinc and copper play distinct roles in macrophage-mediated killing of this pathogen. Collectively, this study supports the targeting of metal ion homeostatic mechanisms as an effective antimicrobial strategy against multi-drug resistant bacterial pathogens.

Zinc supplementation leads to immune modulation and improved survival in a juvenile model of murine sepsis.

PubMed

Ganatra, Hammad A; Varisco, Brian M; Harmon, Kelli; Lahni, Patrick; Opoka, Amy; Wong, Hector R

2017-01-01

Children with severe sepsis are known to have altered zinc homeostasis and decreased circulating zinc levels, suggesting a role for zinc supplementation to improve outcomes. We tested the hypothesis that zinc supplementation would improve survival in a juvenile model of polymicrobial sepsis. Juvenile (13-14-d-old) C57BL/6 mice were treated with 10 mg/kg of zinc via i.p. injections (or vehicle) for 3 d prior to induction of polymicrobial sepsis via i.p. cecal slurry injections. Survival after sepsis was followed for 3 d, and bacterial clearance, ex vivo phagocytosis, systemic inflammatory markers and neutrophil extracellular trap (NET) formation were quantified. We found a significant survival benefit and decreased bacterial burden among zinc supplemented mice when compared with the control group. Zinc supplementation also resulted in enhanced phagocytic activity, greater neutrophil recruitment in the peritoneal cavity and NET formation, suggesting a possible mechanism for improved bacterial clearance and survival. We also noted decreased serum cytokine levels and decreased myeloperoxidase activity in lung tissue following zinc supplementation, suggesting attenuation of the systemic inflammatory response. In conclusion, zinc supplementation improves bacterial clearance, and hence survival, in juvenile mice with polymicrobial sepsis.

Hair Zinc: an Index for Zinc Status in Under-Five Children from Low-Income Communities in Kanam Area of North-Central Nigeria.

PubMed

Jaryum, Kiri H; Okoye, Zebulon Sunday C; Stoecker, Barbara

2018-06-01

Nutritional deficiencies of trace elements are among the top ten causes of death in Sub Saharan Africa. In Kanam Local Government Area of Nigeria, the problem is compounded by high levels of poverty and illiteracy. Abnormally low hair zinc levels are important, sensitive diagnostic biochemical indices of Zinc deficiency. The purpose of this study is to assess the zinc status of children less than 5 years in Kanam local government area, north-central Nigeria, by measuring the zinc level in hair samples collected from 44 under-5 children across the area. A household survey was made to assess the pattern and frequency of consumption of zinc-rich foods which was done by means of questionnaire. Hair samples were analysed for zinc content by the inductively coupled plasma-mass spectrophotometry (ICP-MS). The data were analysed statistically using the Student's t test, z test, and Pearson correlation, while questionnaire-captured data were analysed by simple arithmetic. The results of the analyses showed that the average hair zinc level was 74.35 ± 48.05 μg/g. This was below the normal range of 130-140 μg/g, for children less than 5 years. Based on the results, 86.36% have hair zinc level below the lower limit of the normal range of 130 μg/g. Between the gender, boys have higher hair zinc content than girls. Data from the questionnaire showed that 53.45% of the population studied have poor/inadequate intake of zinc-rich foods of animal origin, a dietary behaviour reported to predispose to micronutrient deficiency, including zinc.

Increases in extracellular zinc in the amygdala in acquisition and recall of fear experience and their roles in response to fear.

PubMed

Takeda, A; Tamano, H; Imano, S; Oku, N

2010-07-14

The amygdala is enriched with histochemically reactive zinc, which is dynamically coupled with neuronal activity and co-released with glutamate. The dynamics of the zinc in the amygdala was analyzed in rats, which were subjected to inescapable stress, to understand the role of the zinc in emotional behavior. In the communication box, two rats were subjected to foot shock stress and anxiety stress experiencing emotional responses of foot-shocked rat under amygdalar perfusion. Extracellular zinc was increased by foot shock stress, while decreased by anxiety stress, suggesting that the differential changes in extracellular zinc are associated with emotional behavior. In rats conditioned with foot shock, furthermore, extracellular zinc was increased again in the recall of fear (foot shock) in the same box without foot shock. When this recall was performed under perfusion with CaEDTA, a membrane-impermeable zinc chelator, to examine the role of the increase in extracellular zinc, the time of freezing behavior was more increased, suggesting that zinc released in the lateral amygdala during the recall of fear participates in freezing behavior. To examine the role of the increase in extracellular zinc during fear conditioning, fear conditioning was also performed under perfusion with CaEDTA. The time of freezing behavior was more increased in the contextual recall, suggesting that zinc released in the lateral nucleus during fear conditioning also participates in freezing behavior in the recall. In brain slice experiment, CaEDTA enhanced presynaptic activity (exocytosis) in the lateral nucleus after activation of the entorhinal cortex. The present paper demonstrates that zinc released in the lateral amygdala may participate in emotional behavior in response to fear. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Detection of zinc translocation into apical dendrite of CA1 pyramidal neuron after electrical stimulation.

PubMed

Suh, Sang Won

2009-02-15

Translocation of the endogenous cation zinc from presynaptic terminals to postsynaptic neurons after brain insult has been implicated as a potential neurotoxic event. Several studies have previously demonstrated that a brief electrical stimulation is sufficient to induce the translocation of zinc from presynaptic vesicles into the cytoplasm (soma) of postsynaptic neurons. In the present work I have extended those findings in three ways: (i) providing evidence that zinc translocation occurs into apical dendrites, (ii) presenting data that there is an apparent translocation into apical dendrites when only a zinc-containing synaptic input is stimulated, and (iii) presenting data that there is no zinc translocation into apical dendrite of ZnT3 KO mice following electrical stimulation. Hippocampal slices were preloaded with the "trappable" zinc fluorescent probe, Newport Green. After washout, a single apical dendrite in the stratum radiatum of hippocampal CA1 area was selected and focused on. Burst stimulation (100Hz, 500microA, 0.2ms, monopolar) was delivered to either the adjacent Schaffer-collateral inputs (zinc-containing) or to the adjacent temporo-ammonic inputs (zinc-free) to the CA1 dendrites. Stimulation of the Schaffer collaterals increased the dendritic fluorescence, which was blocked by TTX, low-Ca medium, or the extracellular zinc chelator, CaEDTA. Stimulation of the temporo-ammonic pathway caused no significant rise in the fluorescence. Genetic depletion of vesicular zinc by ZnT3 KO showed no stimulation-induced apical dendrite zinc rise. The present study provides evidence that synaptically released zinc translocates into postsynaptic neurons through the apical dendrites of CA1 pyramidal neurons during physiological synaptic activity.

Compound heterozygous mutations in SLC30A2/ZnT2 results in low milk zinc concentrations: a novel mechanism for zinc deficiency in a breast-fed infant.

PubMed

Itsumura, Naoya; Inamo, Yasuji; Okazaki, Fumiko; Teranishi, Fumie; Narita, Hiroshi; Kambe, Taiho; Kodama, Hiroko

2013-01-01

Zinc concentrations in breast milk are considerably higher than those of the maternal serum, to meet the infant's requirements for normal growth and development. Thus, effective mechanisms ensuring secretion of large amounts of zinc into the milk operate in mammary epithelial cells during lactation. ZnT2 was recently found to play an essential role in the secretion of zinc into milk. Heterozygous mutations of human ZnT2 (hZnT2), including H54R and G87R, in mothers result in low (>75% reduction) secretion of zinc into the breast milk, and infants fed on the milk develop transient neonatal zinc deficiency. We identified two novel missense mutations in the SLC30A2/ZnT2 gene in a Japanese mother with low milk zinc concentrations (>90% reduction) whose infant developed severe zinc deficiency; a T to C transition (c.454T>C) at exon 4, which substitutes a tryptophan residue with an arginine residue (W152R), and a C to T transition (c.887C>T) at exon 7, which substitutes a serine residue with a leucine residue (S296L). Biochemical characterization using zinc-sensitive DT40 cells indicated that the W152R mutation abolished the abilities to transport zinc and to form a dimer complex, indicating a loss-of-function mutation. The S296L mutation retained both abilities but was extremely destabilized. The two mutations were found on different alleles, indicating that the genotype of the mother with low milk zinc was compound heterozygous. These results show novel compound heterozygous mutations in the SLC30A2/ZnT2 gene causing zinc deficiency in a breast-fed infant.

Effects of zinc and multimineral vitamin supplementation on glycemic and lipid control in adult diabetes.

PubMed

Gunasekara, Priyanka; Hettiarachchi, Manjula; Liyanage, Chandrani; Lekamwasam, Sarath

2011-01-26

To evaluate the effects of zinc with or without other antioxidants on blood glucose, lipid profile, and serum creatinine in adult diabetics on long-term follow-up. Patients (n = 96) were randomly allocated to three groups: group A (n = 29) was supplemented with oral zinc sulfate (22 mg/day) and multivitamin/mineral (zinc+MVM) preparation; group B (n = 31) was given the same preparation without zinc (MVM); and group C (n = 36) was given a matching placebo for a period of 4 months in a single-blinded study. Blood samples were taken at baseline and after 4 months of supplementation to assess blood glucose (fasting and postprandial) and glycosylated hemoglobin (Hb(A1C)%) and serum levels of zinc, creatinine, and lipids. The zinc+MVM group had a mean change of fasting blood sugar -0.33 mmol/L (standard error of the mean 0.21 mmol/L) and was significant (P = 0.05) when compared with the other two groups (mean change in the MVM group +0.19 (0.31) mmol/L and +0.43 (0.23) mmol/L in the control group, respectively). The Hb(A1C)% level reduced significantly, irrespective of the baseline level, in zinc+MVM-supplemented individuals. In the other two groups, the change of Hb(A1C)% level was not significant. Serum lipid levels reduced significantly in the zinc+MVM and MVM groups. Zinc+MVM supplementation showed beneficial effects in the metabolic control of adult diabetics in addition to elevating their serum zinc level. Zinc supplementation improved glycemic control measured by Hb(A1C)% and fasting and postprandial glucose. Furthermore, zinc supplementation lowered serum cholesterol and cholesterol/high-density lipoprotein ratio.

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

PubMed Central

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

2008-01-01

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

Compound Heterozygous Mutations in SLC30A2/ZnT2 Results in Low Milk Zinc Concentrations: A Novel Mechanism for Zinc Deficiency in a Breast-Fed Infant

PubMed Central

Itsumura, Naoya; Inamo, Yasuji; Okazaki, Fumiko; Teranishi, Fumie; Narita, Hiroshi; Kambe, Taiho; Kodama, Hiroko

2013-01-01

Zinc concentrations in breast milk are considerably higher than those of the maternal serum, to meet the infant's requirements for normal growth and development. Thus, effective mechanisms ensuring secretion of large amounts of zinc into the milk operate in mammary epithelial cells during lactation. ZnT2 was recently found to play an essential role in the secretion of zinc into milk. Heterozygous mutations of human ZnT2 (hZnT2), including H54R and G87R, in mothers result in low (>75% reduction) secretion of zinc into the breast milk, and infants fed on the milk develop transient neonatal zinc deficiency. We identified two novel missense mutations in the SLC30A2/ZnT2 gene in a Japanese mother with low milk zinc concentrations (>90% reduction) whose infant developed severe zinc deficiency; a T to C transition (c.454T>C) at exon 4, which substitutes a tryptophan residue with an arginine residue (W152R), and a C to T transition (c.887C>T) at exon 7, which substitutes a serine residue with a leucine residue (S296L). Biochemical characterization using zinc-sensitive DT40 cells indicated that the W152R mutation abolished the abilities to transport zinc and to form a dimer complex, indicating a loss-of-function mutation. The S296L mutation retained both abilities but was extremely destabilized. The two mutations were found on different alleles, indicating that the genotype of the mother with low milk zinc was compound heterozygous. These results show novel compound heterozygous mutations in the SLC30A2/ZnT2 gene causing zinc deficiency in a breast-fed infant. PMID:23741301

Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis

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

Plapp, Bryce V.; Savarimuthu, Baskar Raj; Ferraro, Daniel J.

During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5'-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentatemore » chelators 2,2'-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme–NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ~1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD+ and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water.« less

Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis

PubMed Central

2017-01-01

During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5′-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators 2,2′-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme–NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ∼1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD+ and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water. PMID:28640600

[Influence of hormonal contraceptives on indices of zinc homeostasis and bone remodeling in young adult women].

PubMed

Simões, Tania Mara Rodrigues; Zapata, Carmiña Lucía Vargas; Donangelo, Carmen Marino

2015-09-01

To investigate the influence of the use of oral hormonal contraceptive agents (OCA) on the biochemical indices related to metabolic zinc utilization and distribution, and to bone turnover in young adult women. Cross-sectional study. Blood and urine samples from non-users (-OCA; control; n=69) and users of hormonal contraceptives for at least 3 months (+OCA; n=62) were collected under controlled conditions. Indices of zinc homeostasis and of bone turnover were analyzed in serum or plasma (total, albumin-bound and α2-macroglobulin-bound zinc, albumin and total and bone alkaline phosphatase activity), in erythrocytes (zinc and metallothionein) and in urine (zinc, calcium and hydroxyproline). The habitual zinc and calcium intakes were evaluated by a food frequency questionnaire. Dietary zinc intake was similar in both groups and on average above recommended values, whereas calcium intake was similarly sub-adequate in +OCA and -OCA. Compared to controls, +OCA had lower concentrations of total and α2-macroglobulin-bound zinc (11 and 28.5%, respectively, p<0.001), serum albumin (13%, p<0.01), total and bone-specific alkaline phosphatase activity (13 and 18%, respectively, p<0.05), erythrocyte metallothionein (13%, p<0.01), and, urinary zinc (34%, p<0.05). OCA use decreases serum zinc, alters zinc distribution in major serum fractions with possible effects on tissue uptake, enhances zinc retention in the body and decreases bone turnover. Prolonged OCA use may lead to lower peak bone mass and/or to impaired bone mass maintenance in young women, particularly in those with marginal calcium intake. The observed OCA effects were more evident in women younger than 25 years and in nulliparous women, deserving special attention in future studies.

Analysis of zinc binding sites in protein crystal structures.

PubMed

Alberts, I L; Nadassy, K; Wodak, S J

1998-08-01

The geometrical properties of zinc binding sites in a dataset of high quality protein crystal structures deposited in the Protein Data Bank have been examined to identify important differences between zinc sites that are directly involved in catalysis and those that play a structural role. Coordination angles in the zinc primary coordination sphere are compared with ideal values for each coordination geometry, and zinc coordination distances are compared with those in small zinc complexes from the Cambridge Structural Database as a guide of expected trends. We find that distances and angles in the primary coordination sphere are in general close to the expected (or ideal) values. Deviations occur primarily for oxygen coordinating atoms and are found to be mainly due to H-bonding of the oxygen coordinating ligand to protein residues, bidentate binding arrangements, and multi-zinc sites. We find that H-bonding of oxygen containing residues (or water) to zinc bound histidines is almost universal in our dataset and defines the elec-His-Zn motif. Analysis of the stereochemistry shows that carboxyl elec-His-Zn motifs are geometrically rigid, while water elec-His-Zn motifs show the most geometrical variation. As catalytic motifs have a higher proportion of carboxyl elec atoms than structural motifs, they provide a more rigid framework for zinc binding. This is understood biologically, as a small distortion in the zinc position in an enzyme can have serious consequences on the enzymatic reaction. We also analyze the sequence pattern of the zinc ligands and residues that provide elecs, and identify conserved hydrophobic residues in the endopeptidases that also appear to contribute to stabilizing the catalytic zinc site. A zinc binding template in protein crystal structures is derived from these observations.

Zinc Acetate Lozenges May Improve the Recovery Rate of Common Cold Patients: An Individual Patient Data Meta-Analysis.

PubMed

Hemilä, Harri; Fitzgerald, James T; Petrus, Edward J; Prasad, Ananda

2017-01-01

A previous meta-analysis of 3 zinc acetate lozenge trials estimated that colds were on average 40% shorter for the zinc groups. However, the duration of colds is a time outcome, and survival analysis may be a more informative approach. The objective of this individual patient data (IPD) meta-analysis was to estimate the effect of zinc acetate lozenges on the rate of recovery from colds. We analyzed IPD for 3 randomized placebo-controlled trials in which 80-92 mg/day of elemental zinc were administered as zinc acetate lozenges to 199 common cold patients. We used mixed-effects Cox regression to estimate the effect of zinc. Patients administered zinc lozenges recovered faster by rate ratio 3.1 (95% confidence interval, 2.1-4.7). The effect was not modified by age, sex, race, allergy, smoking, or baseline common cold severity. On the 5th day, 70% of the zinc patients had recovered compared with 27% of the placebo patients. Accordingly, 2.6 times more patients were cured in the zinc group. The difference also corresponds to the number needed to treat of 2.3 on the 5th day. None of the studies observed serious adverse effects of zinc. The 3-fold increase in the rate of recovery from the common cold is a clinically important effect. The optimal formulation of zinc lozenges and an ideal frequency of their administration should be examined. Given the evidence of efficacy, common cold patients may be instructed to try zinc acetate lozenges within 24 hours of onset of symptoms. © The Author 2017. Published by Oxford University Press on behalf of Infectious Diseases Society of America.

Toxic and nontoxic components of botulinum neurotoxin complex are evolved from a common ancestral zinc protein

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

Inui, Ken; Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472; Sagane, Yoshimasa

2012-03-16

Highlights: Black-Right-Pointing-Pointer BoNT and NTNHA proteins share a similar protein architecture. Black-Right-Pointing-Pointer NTNHA and BoNT were both identified as zinc-binding proteins. Black-Right-Pointing-Pointer NTNHA does not have a classical HEXXH zinc-coordinating motif similar to that found in all serotypes of BoNT. Black-Right-Pointing-Pointer Homology modeling implied probable key residues involved in zinc coordination. -- Abstract: Zinc atoms play an essential role in a number of enzymes. Botulinum neurotoxin (BoNT), the most potent toxin known in nature, is a zinc-dependent endopeptidase. Here we identify the nontoxic nonhemagglutinin (NTNHA), one of the BoNT-complex constituents, as a zinc-binding protein, along with BoNT. A protein structuremore » classification database search indicated that BoNT and NTNHA share a similar domain architecture, comprising a zinc-dependent metalloproteinase-like, BoNT coiled-coil motif and concanavalin A-like domains. Inductively coupled plasma-mass spectrometry analysis demonstrated that every single NTNHA molecule contains a single zinc atom. This is the first demonstration of a zinc atom in this protein, as far as we know. However, the NTNHA molecule does not possess any known zinc-coordinating motif, whereas all BoNT serotypes possess the classical HEXXH motif. Homology modeling of the NTNHA structure implied that a consensus K-C-L-I-K-X{sub 35}-D sequence common among all NTNHA serotype molecules appears to coordinate a single zinc atom. These findings lead us to propose that NTNHA and BoNT may have evolved distinct functional specializations following their branching out from a common ancestral zinc protein.« less

Nanocarrier-mediated foliar zinc fertilization influences expression of metal homeostasis related genes in flag leaves and enhances gluten content in durum wheat.

PubMed

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

2018-01-01

Wheat is the staple food for most of the world's population; however, it is a poor source of zinc. Foliar fertilization of zinc via zinc loaded chitosan nanocarriers (Zn-CNP) post-anthesis has proved to be a promising approach for grain zinc enhancement in durum wheat as evidenced in our earlier study. However, the molecular mechanism of uptake of zinc via Zn-CNP remains unclear. Foliar application of Zn-CNP was performed at post anthesis stages in two durum wheat cultivars (MACS 3125 and UC1114, containing the Gpc-B1 gene), and expression levels of several metal-related genes were analyzed during early senescence. Zn-CNP application indeed caused changes in gene expression as revealed by qPCR data on representative genes involved in metal homeostasis, phloem transporters, and leaf senescence. Furthermore, zinc-regulated transporters and iron (Fe)-regulated transporter-like protein (ZIP) family [ZIP1, ZIP7, ZIP15], CA (carbonic anhydrase), and DMAS (2'-deoxymugineic acid synthase) in flag leaves exhibited significant correlation with zinc content in the seeds. The analysis of grain endosperm proteins showed enhancement of gamma gliadins while other gluten subunits decreased. Gene expression within ZIP family members varied with the type of cultivar mostly attributed to the Gpc-B1, concentration of external zinc ions as well as the type of tissue analyzed. Correlation analysis revealed the involvement of the selected genes in zinc enhancement. At the molecular level, uptake of zinc via Zn-CNP nanocarrier was comparable to the uptake of zinc via common zinc fertilizers i.e. ZnSO4.

Determinants of serum zinc concentrations in a population of French middle-age subjects (SU.VI.MAX cohort).

PubMed

Arnaud, J; Touvier, M; Galan, P; Andriollo-Sanchez, M; Ruffieux, D; Roussel, A-M; Hercberg, S; Favier, A

2010-10-01

Few studies have been conducted on determinants of serum zinc concentration, especially in France. The aim of this study was to investigate the relationships between serum zinc concentrations, and age, education, living area and life style in a large sample cohort of French adults. Blood samples were collected after 12-h fasting in French adults (7448 women, 35-65 years old and 4926 men, 45-65 years old) participating to the SUpplementation in AntioXidant VItamins and Minerals cohort at enrolment. Serum zinc was determined by flame atomic absorption. Serum zinc concentration was lower in women (mean: 12.9 μmol/l, 95% confidence interval: 9.2-16.6 μmol/l) compared with men (mean: 13.4 μmol/l, 95% confidence interval: 9.7-17.1 μmol/l, P<0.0001). In total, 10% of the women showed serum zinc values <10.7 μmol/l and 10% of the men showed serum zinc values <11.3 μmol/l. Age was negatively associated with serum zinc only in men (P=0.001). In women, a positive association between smoking and serum zinc concentration (P=0.0003), and a negative relationship between highest education level and serum zinc concentration (P=0.01) were observed. With regard to geographical areas, the highest serum zinc concentrations were found in the Center, and the lowest in the Southwest of France for both men and women. The association between serum zinc concentrations and food categories or macronutrient intake disappeared after stratifying by gender. Age, gender and geographic area seem the main determinants of serum zinc concentrations in this study.

40 CFR 415.630 - Applicability; description of the zinc sulfate production subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... sulfate production subcategory. 415.630 Section 415.630 Protection of Environment ENVIRONMENTAL PROTECTION... 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, 2012 CFR

2012-07-01

... sulfate production subcategory. 415.630 Section 415.630 Protection of Environment ENVIRONMENTAL PROTECTION... 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, 2014 CFR

2014-07-01

... sulfate production subcategory. 415.630 Section 415.630 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Zinc Sulfate Production Subcategory § 415.630 Applicability; description of the zinc sulfate... production of zinc sulfate. ...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Special Requirements for Certain...-proof motors approved for use in Class I, Division 1, Group B atmospheres or equivalent motors approved...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Special Requirements for Certain...-proof motors approved for use in Class I, Division 1, Group B atmospheres or equivalent motors approved...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Special Requirements for Certain...-proof motors approved for use in Class I, Division 1, Group B atmospheres or equivalent motors approved...

Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

DOEpatents

Adler, T.C.; McLarnon, F.R.; Cairns, E.J.

1994-04-12

An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing KOH and a combination of KF and K[sub 2]CO[sub 3] salts which inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics. 8 figures.

Transient symptomatic zinc deficiency in a preterm exclusively breast-fed infant.

PubMed

Laureano, André; Brás, Susana; Carvalho, Rodrigo; Amaro, Cristina; Cardoso, Jorge

2014-02-18

A 5-month-old female infant, preterm, exclusively breast-fed, presented with a 2-month history of erythematous, erosive, and crusted patches and plaques in a peri-oral, scalp, genital, and peri-anal distribution. A clinical diagnosis of zinc deficiency was confirmed by a low serum zinc level in the infant and decreased maternal breast milk zinc. Complete resolution occurred within two weeks of oral zinc supplementation. Acquired zinc deficiency is a rare nutritional disorder of infants. Early diagnosis and adequate treatment will prevent associated morbidity and complications.

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.

Zinc transport in rabbit tissues. Some hormonal aspects of the turnover of zinc in female reproductive organs, liver and body fluids

PubMed Central

McIntosh, J. E. A.; Lutwak-Mann, C.

1972-01-01

1. To investigate the influence of hormonal conditions upon the kinetics of zinc transport, specific radioactivity of 65Zn was determined in certain tissues and fluids from unmated or pregnant rabbits during the first half of gestation. 2. Compartmental analysis was used to find the simplest mathematical model that simulated satisfactorily tracer behaviour. Models were fitted to experimental results by a numerical procedure using a computer. 3. The kinetics of zinc exchange in most tissues investigated could adequately be described by a three-compartment model, in which total tissue zinc content was divided into a rapidly exchanging pool, with a turnover time of about 1h, and a slowly exchanging pool, the turnover time of which was in liver 15h, in peak-stage corpus luteum 8h, and in the other tissues 30–70h. 4. In rabbit endometrium zinc transport varied with hormonal conditions, the turnover rate being higher in non-pregnant than pregnant endometrium. 5. Uptake of 65Zn by uterine fluid was slow, and in the free-lying embryos (blastocysts) slower still, in keeping with uterine fluid acting as carrier of zinc into the unimplanted embryos. 6. In placental tissue zinc transport varied with gestational stage. Foetal placenta exchanged zinc with blood plasma four times faster than maternal placenta. In foetuses zinc turnover time and flux equalled that of the slow zinc compartment in foetal placenta. 7. Corpus luteum on days 5–6 of gestation showed peak specific radioactivity and zinc flux values, which exceeded those of all other tissues. 8. In liver the slow zinc compartment had a higher rate of turnover than corresponding compartments in tissues other than peak-stage corpus luteum, but no hormone-dependent changes were observed. 9. Zinc uptake by erythrocytes was the slowest of all examined. PMID:5073239

Randomized trial of the effect of zinc supplementation on the mental health of school-age children in Guatemala123

PubMed Central

DiGirolamo, Ann M; Ramirez-Zea, Manuel; Wang, Meng; Flores-Ayala, Rafael; Martorell, Reynaldo; Neufeld, Lynnette M; Ramakrishnan, Usha; Sellen, Daniel; Black, Maureen M; Stein, Aryeh D

2010-01-01

Background: Rates of mental illness in children are increasing throughout the world. Observational studies of depression, anxiety, and attention-deficit hyperactivity disorder suggest that zinc is an alternative treatment. Objective: We examined the effect of zinc supplementation on the mental health of school-age children in Guatemala. Design: From January to October 2006, we conducted a 6-mo randomized, double-blind, controlled trial comparing zinc supplementation (10 mg ZnO/d for 5 d/wk) with a placebo (10 mg glucose) in 674 Guatemalan children in grades 1–4. Outcome measures included internalizing (ie, depression and anxiety) and externalizing (ie, hyperactivity and conduct disorder) problem behaviors, positive behaviors (ie, socialization and leadership), and serum zinc concentrations. Results: Zinc and placebo groups did not differ significantly in any behavioral measures at baseline or at follow-up. At baseline, 21.4% of children had serum zinc concentrations <65 μg/dL. At follow-up, both groups improved significantly, and zinc concentrations were higher in the zinc group. Increases in serum zinc concentrations were inversely associated with decreases in depressive symptoms (estimate: −0.01 points per μg Zn/dL; P = 0.01), anxiety (estimate: −0.012 points per μg Zn/dL; P = 0.02), internalizing symptoms (estimate: −0.021 points per μg Zn/dL; P = 0.02), and social skills (estimate: −0.019 points per μg Zn/dL; P = 0.01) in adjusted models that were controlled for child age, sex, socioeconomic status, household, and treatment group. Conclusions: Six months of zinc supplementation did not induce differences in mental health outcomes between zinc and placebo groups. However, increases in serum zinc concentrations were associated with decreases in internalizing symptoms (ie, depression and anxiety) in a community-based sample of children at risk of zinc deficiency. This trial was registered at clinicaltrials.gov as NCT00283660. PMID:20881069

Zinc stimulates glucose oxidation and glycemic control by modulating the insulin signaling pathway in human and mouse skeletal muscle cell lines.

PubMed

Norouzi, Shaghayegh; Adulcikas, John; Sohal, Sukhwinder Singh; Myers, Stephen

2018-01-01

Zinc is a metal ion that is an essential cell signaling molecule. Highlighting this, zinc is an insulin mimetic, activating cellular pathways that regulate cellular homeostasis and physiological responses. Previous studies have linked dysfunctional zinc signaling with several disease states including cancer, obesity, cardiovascular disease and type 2 diabetes. The present study evaluated the insulin-like effects of zinc on cell signaling molecules including tyrosine, PRSA40, Akt, ERK1/2, SHP-2, GSK-3β and p38, and glucose oxidation in human and mouse skeletal muscle cells. Insulin and zinc independently led to the phosphorylation of these proteins over a 60-minute time course in both mouse and human skeletal muscle cells. Similarly, utilizing a protein array we identified that zinc could active the phosphorylation of p38, ERK1/2 and GSK-3B in human and ERK1/2 and GSK-3B in mouse skeletal muscle cells. Glucose oxidation assays were performed on skeletal muscle cells treated with insulin, zinc, or a combination of both and resulted in a significant induction of glucose consumption in mouse (p<0.01) and human (p<0.05) skeletal muscle cells when treated with zinc alone. Insulin, as expected, increased glucose oxidation in mouse (p<0.001) and human (0.001) skeletal muscle cells, however the combination of zinc and insulin did not augment glucose consumption in these cells. Zinc acts as an insulin mimetic, activating key molecules implicated in cell signaling to maintain glucose homeostasis in mouse and human skeletal muscle cells. Zinc is an important metal ion implicated in several biological processes. The role of zinc as an insulin memetic in activating key signaling molecules involved in glucose homeostasis could provide opportunities to utilize this ion therapeutically in treating disorders associated with dysfunctional zinc signaling.

Zinc Levels in Left Ventricular Hypertrophy.

PubMed

Huang, Lei; Teng, Tianming; Bian, Bo; Yao, Wei; Yu, Xuefang; Wang, Zhuoqun; Xu, Zhelong; Sun, Yuemin

2017-03-01

Zinc is one of the most important trace elements in the body and zinc homeostasis plays a critical role in maintaining cellular structure and function. Zinc dyshomeostasis can lead to many diseases, such as cardiovascular disease. Our aim was to investigate whether there is a relationship between zinc and left ventricular hypertrophy (LVH). A total of 519 patients was enrolled and their serum zinc levels were measured in this study. We performed analyses on the relationship between zinc levels and LVH and the four LV geometry pattern patients: normal LV geometry, concentric remodeling, eccentric LVH, and concentric LVH. We performed further linear and multiple regression analyses to confirm the relationship between zinc and left ventricular mass (LVM), left ventricular mass index (LVMI), and relative wall thickness (RWT). Our data showed that zinc levels were 710.2 ± 243.0 μg/L in the control group and were 641.9 ± 215.2 μg/L in LVH patients. We observed that zinc levels were 715 ± 243.5 μg/L, 694.2 ± 242.7 μg/L, 643.7 ± 225.0 μg/L, and 638.7 ± 197.0 μg/L in normal LV geometry, concentric remodeling, eccentric LVH, and concentric LVH patients, respectively. We further found that there was a significant inverse linear relationship between zinc and LVM (p = 0.001) and LVMI (p = 0.000) but did not show a significant relationship with RWT (p = 0.561). Multiple regression analyses confirmed that the linear relationship between zinc and LVM and LVMI remained inversely significant. The present study revealed that serum zinc levels were significantly decreased in the LVH patients, especially in the eccentric LVH and concentric LVH patients. Furthermore, zinc levels were significantly inversely correlated with LVM and LVMI.

Potentiometric Zinc Ion Sensor Based on Honeycomb-Like NiO Nanostructures

PubMed Central

Abbasi, Mazhar Ali; Ibupoto, Zafar Hussain; Hussain, Mushtaque; Khan, Yaqoob; Khan, Azam; Nur, Omer; Willander, Magnus

2012-01-01

In this study honeycomb-like NiO nanostructures were grown on nickel foam by a simple hydrothermal growth method. The NiO nanostructures were characterized by field emission electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) techniques. The characterized NiO nanostructures were uniform, dense and polycrystalline in the crystal phase. In addition to this, the NiO nanostructures were used in the development of a zinc ion sensor electrode by functionalization with the highly selective zinc ion ionophore 12-crown-4. The developed zinc ion sensor electrode has shown a good linear potentiometric response for a wide range of zinc ion concentrations, ranging from 0.001 mM to 100 mM, with sensitivity of 36 mV/decade. The detection limit of the present zinc ion sensor was found to be 0.0005 mM and it also displays a fast response time of less than 10 s. The proposed zinc ion sensor electrode has also shown good reproducibility, repeatability, storage stability and selectivity. The zinc ion sensor based on the functionalized NiO nanostructures was also used as indicator electrode in potentiometric titrations and it has demonstrated an acceptable stoichiometric relationship for the determination of zinc ion in unknown samples. The NiO nanostructures-based zinc ion sensor has potential for analysing zinc ion in various industrial, clinical and other real samples. PMID:23202217

Inhibition of presynaptic activity by zinc released from mossy fiber terminals during tetanic stimulation.

PubMed

Minami, Akira; Sakurada, Naomi; Fuke, Sayuri; Kikuchi, Kazuya; Nagano, Tetsuo; Oku, Naoto; Takeda, Atsushi

2006-01-01

Zinc exists in high densities in the giant boutons of hippocampal mossy fibers. On the basis of the evidence that zinc decreases extracellular glutamate concentration in the hippocampus, the presynaptic action of zinc released from mossy fibers during high-frequency (tetanic) stimulation was examined using hippocampal slices. The increase in zinc-specific fluorescent signals was observed in both extracellular and intracellular compartments in the mossy fiber terminals during the delivery of tetanic stimuli (100 Hz, 1 sec) to the dentate granule cell layer, suggesting that zinc released from mossy fibers is immediately retaken up by mossy fibers. When mossy fiber terminals were preferentially double-stained with zinc and calcium indicators and tetanic stimuli (100 Hz, 1 sec) were delivered to the dentate granule cell layer, the increase in calcium orange signal during the stimulation was enhanced in mossy fiber terminals by addition of CaEDTA, a membrane-impermeable zinc chelator, and was suppressed by addition of zinc. The decrease in FM4-64 signal (vesicular exocytosis) during tetanic stimulation (10 Hz, 180 sec), which induced mossy fiber long-term potentiation, was also enhanced in mossy fiber terminals by addition of CaEDTA and was suppressed by addition of zinc. The present study demonstrates that zinc released from mossy fibers may be a negative-feedback factor against presynaptic activity during tetanic stimulation.

X-ray absorption Studies of Zinc species in Centella asiatica

NASA Astrophysics Data System (ADS)

Dehipawala, Sunil; Cheung, Tak; Hogan, Clayton; Agoudavi, Yao; Dehipawala, Sumudu

2013-03-01

Zinc is a very important mineral present in a variety of vegetables. It is an essential element in cellular metabolism and several bodily functions. We used X-ray fluorescence, and X-ray Absorption near Edge structure(XANES) to study the amount of zinc present in several leafy vegetables as well as its chemical environment within the plant. Main absorption edge position of XANES is sensitive to the oxidation state of zinc and is useful when comparing the type of zinc present in different vegetables to the standard zinc present in supplements. Normalized main edge height is proportional to the amount of zinc present in the sample. Several leafy greens were used in this study, such as Spinacia oleracea, Basella alba, Brassica oleracea, Cardiospermum halicacabumand Centella asiatica. All of these plant leaves contained approximately the same amount of zinc in the leaf portion of the plant and a slightly lower amount in the stems, except Centella asiatica. Both leaves and stems of the plant Centella asiatica contained nearly two times the zinc compared to other plants. Further investigation of zinc's chemical environment within Centella asiatica could lead to a much more efficient dietary consumption of zinc. Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886

Prevalence of zinc deficiency among rural women during childbearing age in Peshawar, Pakistan.

PubMed

Akhtar, Tasleem; Khan, Mir Hassan; Zahoorullah; Hussain, Hamid; Nazli, Rubina; Lutfullah, Ghosia

2014-01-01

Zinc deficiency is a commonly reported health problem throughout the world. This cross sectional survey was conducted in rural Peshawar with an aim to estimate the prevalence of zinc deficiency in women of child bearing age and find its association with age, marital, pregnancy status and parity. Data was collected from 353 women age 15-45 years. EPI INFO version 6.04 was used for data analysis. Overall 98 (27.8 %) women were zinc deficient (<80 μg/dL) while 31 (8.8%) had severe zinc deficiency (<50μg/dL.). Mean zinc level was found to increase gradually with the increase in the age up to 40 years and then starts decreasing significantly beyond this age. A significant decrease (p<0.03) in zinc concentration was found in married as compared to unmarried women. Out of 31 female with severe zinc deficiency, 23 (74.2%) were pregnant. Pregnant women in second (OR (CI) 3.36 (1.52-7.44) p<0.0008) and third ((OR (CI) 3.73 (1.91-7.30) p<0.00002) trimester were 3.4 & 3.7 times, respectively more zinc deficient as compared to control women. Mean zinc levels were significantly lower in women having no children versus women with 1-5 numbers of children. This study concludes that severe zinc deficiency especially prevalent in pregnant women needs urgent correction through food supplementation.

Effects of surface hydroxylation on adhesion at zinc/silica interfaces.

PubMed

Le, Ha-Linh Thi; Goniakowski, Jacek; Noguera, Claudine; Koltsov, Alexey; Mataigne, Jean-Michel

2018-06-06

The weak interaction between zinc and silica is responsible for the poor performance of anti-corrosive galvanic zinc coatings on modern advanced high-strength steels, which are fundamental in the automotive industry, and important for rail transport, shipbuilding, and aerospace. With the goal of identifying possible methods for its improvement, we report an ab initio study of the effect of surface hydroxylation on the adhesion characteristics of model zinc/β-cristobalite interfaces, representative of various surface hydroxylation/hydrogenation conditions. We show that surface silanols resulting from dissociative water adsorption at the most stable stoichiometric (001) and (111) surfaces prevent strong zinc-silica interactions. However, dehydrogenation of such interfaces produces oxygen-rich zinc/silica contacts with excellent adhesion characteristics. These are due to partial zinc oxidation and the formation of strong iono-covalent Zn-O bonds between zinc atoms and the under-coordinated excess anions, remnant of the hydroxylation layer. Interestingly, these interfaces appear as the most thermodynamically stable in a wide range of realistic oxygen-rich and hydrogen-lean environments. We also point out that the partial oxidation of zinc atoms in direct contact with the oxide substrate may somewhat weaken the cohesion in the zinc deposit itself. This fundamental analysis of the microscopic mechanisms responsible for the improved zinc wetting on pre-hydroxylated silica substrates provides useful guidelines towards practical attempts to improve adhesion.

Effect of supplementary zinc on body mass index, pulmonary function and hospitalization in children with cystic fibrosis.

PubMed

Ataee, Pedram; Najafi, Mehri; Gharagozlou, Mohammad; Aflatounian, Majid; Mahmoudi, Maryam; Khodadad, Ahmad; Farahmand, Fatemeh; Motamed, Farzaneh; Fallahi, Glolam Hossein; Kalantari, Najmoddin; Soheili, Habib; Modarresi, Vajiheh; Modarresi, Mozhgan Sabbaghian; Rezaei, Nima

2014-01-01

Zinc deficiency, which is common in patients with cystic fibrosis (CF), can lead to several complications that may increase the number of hospital admissions in this group of patients. As supplementary zinc can prevent such complications, this study was performed to evaluate the effect of supplementary zinc on body mass index (BMI), forced expiratory volume in one second (FEV1) and number of hospitalizations in CF patients. In this study, 30 children with CF, who were referred to the Digestive Diseases Clinic of the Children's Medical Center in Tehran, were enrolled. Supplementary zinc of 2 mg/kg per day was administered to all patients. Serum level of zinc, alkaline phosphatase, and albumin as well as BMI, FEV1, and number of hospitalizations were compared before and after zinc administration. Height (p<0.001), weight (p<0.001) and BMI (p=0.001) were significantly increased after zinc, while the number of hospitalizations was significantly decreased (p=0.023). In contrast to patients with normal pulmonary function tests who received supplement therapy, BMI was not increased in those with abnormal pulmonary function after supplementary zinc. Supplementary zinc can increase BMI in CF patients, mostly in those with normal pulmonary function. While supplementary zinc may decrease the number of hospitalizations, other factors can also influence the hospitalization number.

The Adc/Lmb System Mediates Zinc Acquisition in Streptococcus agalactiae and Contributes to Bacterial Growth and Survival.

PubMed

Moulin, Pauline; Patron, Kévin; Cano, Camille; Zorgani, Mohamed Amine; Camiade, Emilie; Borezée-Durant, Elise; Rosenau, Agnès; Mereghetti, Laurent; Hiron, Aurélia

2016-12-15

The Lmb protein of Streptococcus agalactiae is described as an adhesin that binds laminin, a component of the human extracellular matrix. In this study, we revealed a new role for this protein in zinc uptake. We also identified two Lmb homologs, AdcA and AdcAII, redundant binding proteins that combine with the AdcCB translocon to form a zinc-ABC transporter. Expression of this transporter is controlled by the zinc concentration in the medium through the zinc-dependent regulator AdcR. Triple deletion of lmb, adcA, and adcAII, or that of the adcCB genes, impaired growth and cell separation in a zinc-restricted environment. Moreover, we found that this Adc zinc-ABC transporter promotes S. agalactiae growth and survival in some human biological fluids, suggesting that it contributes to the infection process. These results indicated that zinc has biologically vital functions in S. agalactiae and that, under the conditions tested, the Adc/Lmb transporter constitutes the main zinc acquisition system of the bacterium. A zinc transporter, composed of three redundant binding proteins (Lmb, AdcA, and AdcAII), was characterized in Streptococcus agalactiae This system was shown to be essential for bacterial growth and morphology in zinc-restricted environments, including human biological fluids. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

The role of zinc plus octenidine in the regulation of gene expression: an in vitro study.

PubMed

Lauritano, D; Candotto, V; Bignozzi, C A; Pazzi, D; Carinci, F; Cura, F; Tagliabue, A; Tettamanti, L

2018-01-01

Zinc was known in ancient times, and is diffused in the environment. The potential benefits offered by zinc supplementary therapy have been demonstrated in numerous clinical trials using oral or topical zinc products. The benefit of zinc can be in principle increased through association with other actives. The aim of this study is to evaluate the effect on primary human gingival fibroblast cell of a new formulation containing zinc and octenidine cations. Human gingival fibroblast cells were obtained from three healthy patients (14-year-old man, 15-year-old woman and 20-year-old man) during extraction of teeth. The gene expression of 14 genes (ELANE, FN1, FBN, ITGA1, HAS1, ELN, DSP, ITGB1, HYAL1,TGFB1, TGFB2, TGFB3, TGFBR1 and TGFBR2) was investigated in HGF cell culture treated with 80μm of Octenidine, 1000μm of Zinc, 80μm Octenidine + Zinc solution and the medium alone at 30 min. Prestoblue™ data showed that as the active concentration increases (Octenidine, Zinc and Octenidine + Zinc) the percentage of cell vitality compared to that of untreated cells decrease. In this study, no statistically significant gene expression was observed between cells, treated with difference substances, and control cells. Our results points out that zinc plus octenidine shows a positive potential in periodontal disease treatment.

Evolution of the degradation mechanism of pure zinc stent in the one-year study of rabbit abdominal aorta model.

PubMed

Yang, Hongtao; Wang, Cong; Liu, Chaoqiang; Chen, Houwen; Wu, Yifan; Han, Jintao; Jia, Zichang; Lin, Wenjiao; Zhang, Deyuan; Li, Wenting; Yuan, Wei; Guo, Hui; Li, Huafang; Yang, Guangxin; Kong, Deling; Zhu, Donghui; Takashima, Kazuki; Ruan, Liqun; Nie, Jianfeng; Li, Xuan; Zheng, Yufeng

2017-11-01

In the present study, pure zinc stents were implanted into the abdominal aorta of rabbits for 12 months. Multiscale analysis including micro-CT, scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and histological stainings was performed to reveal the fundamental degradation mechanism of the pure zinc stent and its biocompatibility. The pure zinc stent was able to maintain mechanical integrity for 6 months and degraded 41.75 ± 29.72% of stent volume after 12 months implantation. No severe inflammation, platelet aggregation, thrombosis formation or obvious intimal hyperplasia was observed at all time points after implantation. The degradation of the zinc stent played a beneficial role in the artery remodeling and healing process. The evolution of the degradation mechanism of pure zinc stents with time was revealed as follows: Before endothelialization, dynamic blood flow dominated the degradation of pure zinc stent, creating a uniform corrosion mode; After endothelialization, the degradation of pure zinc stent depended on the diffusion of water molecules, hydrophilic solutes and ions which led to localized corrosion. Zinc phosphate generated in blood flow transformed into zinc oxide and small amounts of calcium phosphate during the conversion of degradation microenvironment. The favorable physiological degradation behavior makes zinc a promising candidate for future stent applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

A multiscale approach to simulating the conformational properties of unbound multi-C₂H₂ zinc finger proteins.

PubMed

Liu, Lei; Wade, Rebecca C; Heermann, Dieter W

2015-09-01

The conformational properties of unbound multi-Cys2 His2 (mC2H2) zinc finger proteins, in which zinc finger domains are connected by flexible linkers, are studied by a multiscale approach. Three methods on different length scales are utilized. First, atomic detail molecular dynamics simulations of one zinc finger and its adjacent flexible linker confirmed that the zinc finger is more rigid than the flexible linker. Second, the end-to-end distance distributions of mC2H2 zinc finger proteins are computed using an efficient atomistic pivoting algorithm, which only takes excluded volume interactions into consideration. The end-to-end distance distribution gradually changes its profile, from left-tailed to right-tailed, as the number of zinc fingers increases. This is explained by using a worm-like chain model. For proteins of a few zinc fingers, an effective bending constraint favors an extended conformation. Only for proteins containing more than nine zinc fingers, is a somewhat compacted conformation preferred. Third, a mesoscale model is modified to study both the local and the global conformational properties of multi-C2H2 zinc finger proteins. Simulations of the CCCTC-binding factor (CTCF), an important mC2H2 zinc finger protein for genome spatial organization, are presented. © 2015 Wiley Periodicals, Inc.

Suppression of zinc dendrites in zinc electrode power cells

NASA Technical Reports Server (NTRS)

Damjanovic, A.; Diggle, J. W.

1970-01-01

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

99. ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON ...

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

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

Cytoprotection by Endogenous Zinc in the Vertebrate Retina

PubMed Central

Anastassov, Ivan; Ripps, Harris; Chappell, Richard L.

2014-01-01

Our recent studies have shown that endogenous zinc, co-released with glutamate from the synaptic terminals of vertebrate retinal photoreceptors, provides a feedback mechanism that reduces calcium entry and the concomitant vesicular release of glutamate. We hypothesized that zinc feedback may serve to protect the retina from glutamate excitotoxicity, and conducted in vivo experiments on the retina of the skate (Raja erinacea) to determine the effects of removing endogenous zinc by chelation. These studies showed that removal of zinc by injecting the zinc chelator histidine results in inner retinal damage similar to that induced by the glutamate receptor agonist kainic acid. In contrast, when an equimolar quantity of zinc followed the injection of histidine, the retinal cells were unaffected. Our results are a good indication that zinc, co-released with glutamate by photoreceptors, provides an auto-feedback system that plays an important cytoprotective role in the retina. PMID:24286124

Ultrasonic measurements of thin zinc layers on concrete

NASA Astrophysics Data System (ADS)

Jansen, Henri; Brooks, Bill; Nguyen, Vinh; Koretsky, Milo

2008-05-01

In order to protect bridges at the coast from corrosion, a thin layer (approximately 0.5 mm) of zinc is sprayed on the concrete of the bridge. When this zinc layer is electrically connected to the reinforcing steel (rebar) and placed at a positive potential with respect to the rebar, oxidation is favored at the zinc layer and reduced at the rebar. The resulting protection of the rebar fails when the zinc layer delaminates from the concrete or when the zinc oxidation product layer becomes too thick. We have used ultrasonic detection to investigate the properties of the zinc layer. This method has been applied very successfully in the semiconductor industry. We present the details of the method and the expected response. Unfortunately, we are not able to measure changes in the zinc layer, because either the frequency we use (10-20 MHz) is too low, or scattering in the concrete is a dominant effect.

Calcium, Iron, and Zinc Bioaccessibilities of Australian Sweet Lupin (Lupinus angustifolius L.) Cultivars.

PubMed

Karnpanit, Weeraya; Coorey, Ranil; Clements, Jon; Benjapong, Wenika; Jayasena, Vijay

2017-06-14

In this study, we aimed to determine the effect of the cultivar and dehulling on calcium, iron, and zinc bioaccessibilities of Australian sweet lupin (ASL). Ten ASL cultivars grown in 2011, 2012, and 2013 in Western Australia were used for the study. The bioaccessibilities of calcium, iron, and zinc in whole seed and dehulled lupin samples were determined using a dialysability method. The cultivar had significant effects on calcium, iron, and zinc contents and their bioaccessibilities. Average bioaccessibilities of 6% for calcium, 17% for iron, and 9% for zinc were found for whole seeds. Dehulled ASL had average calcium, iron, and zinc bioaccessibilities of 11%, 21%, and 12%, respectively. Compared to some other pulses, ASL had better iron bioaccessibility and poorer calcium and zinc bioaccessibilities. Dehulling increased calcium bioaccessibilities of almost all lupin cultivars. The effect of dehulling on iron and zinc bioaccessibilities depends on the ASL cultivar.

Serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin concentrations in infants receiving intravenous zinc and copper supplementation.

PubMed

Lockitch, G; Godolphin, W; Pendray, M R; Riddell, D; Quigley, G

1983-02-01

One hundred twenty-seven newborn infants requiring parenteral nutrition were randomly assigned to receive differing amounts of zinc (40 to 400 micrograms/kg/day) and copper (20 or 40 micrograms/kg/day) supplementation within five birth weight groups (600 to 2,500 gm). The serum zinc concentration remained relatively constant in the group receiving the most zinc supplementation after two weeks of therapy, but declined sharply in the groups receiving less supplementation. No effect of increased copper intake was noted on ceruloplasmin values, but a difference in serum copper concentrations was noted at two weeks. No correlation was noted between serum zinc and copper values or among those for serum zinc, retinol-binding protein, and prealbumin. Reference ranges were defined for serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin in the preterm infant.

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.

A zinc-dependent epitope on the molecule of thymulin, a thymic hormone.

PubMed Central

Dardenne, M; Savino, W; Berrih, S; Bach, J F

1985-01-01

Thymulin is a nonapeptide hormone produced by thymic epithelial cells. Its biological activity is strictly dependent on the presence of the metal zinc in the molecule. Antithymulin monoclonal antibodies have been produced against either the synthetic (AS1) or the natural intraepithelial (AE1) molecule. These monoclonal antibodies were screened for their abilities to inhibit the zinc-dependent biological activity of the hormone and were shown to bind to thymic epithelial cells. By using biological and immunofluorescence assays, the two antibodies were shown to recognize exclusively the zinc-coupled thymulin molecule. Other antithymulin antibodies screened by RIA or ELISA (using a zinc-deprived substrate) recognized a zinc-independent epitope on the thymulin molecule. These data indicate the existence of a zinc-specific conformation on the thymulin molecule. They are in agreement with NMR studies showing that the zinc-containing hormone has a unique structure. Images PMID:2413455

Potential reproduction and response of selenium and zinc mineral supplementation on quality of goat samosir semen

NASA Astrophysics Data System (ADS)

Siswoyo, P.; Tafsin, M.; Handarini, R.

2018-02-01

The present study was conducted to investigate the effect of suppllementattion of selenium and zinc on semen quality and growth of samosir goat. The experimental design used latin square design (4x4). The treatment supplementation mineral on multi nutrient block (MNB) composed of without sipplementation (p0), +10ppm selenium (p1), +10ppm zinc (p2), +10ppm selenium and +10ppm zinc (p3). The result showed that supplementation mineral selenium and zinc increased significantly (p<0.05) average daily growth, feed consumtion, and lower feed convertion ratio. Semen quality of goat were supplemented by selenium and zinc influenced motility, viability, volume concentration, and responding hypo osmotic swelling (HOS). Combination supplementation selenium and zinc significanly had higher semen quality than ither treatment. It is concluded that supplementation selenium and zinc improve growth and semen quality of samosir goat.

Characteristics from Recycled of Zinc Anode used as a Corrosion Preventing Material on Board Ship

NASA Astrophysics Data System (ADS)

Barokah, B.; Semin, S.; Kaligis, D. D.; Huwae, J.; Fanani, M. Z.; Rompas, P. T. D.

2018-02-01

The objective of this research is to obtain the values of chemical composition, electrochemical potential and electrochemical efficiency. Methods used were experiment with physical tests conducted in metallurgical laboratory and DNV-RP-B401 cathode protection design DNV (Det Norske Veritas) standard. The results showed that the composition of chemical as Zinc (Zn), Aluminium, Cadmium, Plumbumb, Copper and Indium is suitable of standard. The values of electrochemical potential and electrochemical efficiency were respectively. However it can be concluded that the normal meaning of recycled zinc anode with increasing melting temperature can produce zinc anode better than original zinc anode and can be used as cathode protection on board ships. This research can assist in the management of used zinc anode waste, the supply of zinc anodes for consumers at relatively low prices, and recommendations of using zinc anodes for the prevention of corrosion on board ship.

Cadmium plating replacements

NASA Technical Reports Server (NTRS)

Nelson, Mary J.; Groshart, Earl C.

1995-01-01

The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

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 and gastrointestinal disease

PubMed Central

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

2014-01-01

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

A role for the Drosophila zinc transporter Zip88E in protecting against dietary zinc toxicity.

PubMed

Richards, Christopher D; Warr, Coral G; Burke, Richard

2017-01-01

Zinc absorption in animals is thought to be regulated in a local, cell autonomous manner with intestinal cells responding to dietary zinc content. The Drosophila zinc transporter Zip88E shows strong sequence similarity to Zips 42C.1, 42C.2 and 89B as well as mammalian Zips 1, 2 and 3, suggesting that it may act in concert with the apically-localised Drosophila zinc uptake transporters to facilitate dietary zinc absorption by importing ions into the midgut enterocytes. However, the functional characterisation of Zip88E presented here indicates that Zip88E may instead play a role in detecting and responding to zinc toxicity. Larvae homozygous for a null Zip88E allele are viable yet display heightened sensitivity to elevated levels of dietary zinc. This decreased zinc tolerance is accompanied by an overall decrease in Metallothionein B transcription throughout the larval midgut. A Zip88E reporter gene is expressed only in the salivary glands, a handful of enteroendocrine cells at the boundary between the anterior and middle midgut regions, and in two parallel strips of sensory cell projections connecting to the larval ventral ganglion. Zip88E expression solely in this restricted subset of cells is sufficient to rescue the Zip88E mutant phenotype. Together, our data suggest that Zip88E may be functioning in a small subset of cells to detect excessive zinc levels and induce a systemic response to reduce dietary zinc absorption and hence protect against toxicity.

Attenuation of hippocampal mossy fiber long-term potentiation by low micromolar concentrations of zinc.

PubMed

Takeda, Atsushi; Kanno, Shingo; Sakurada, Naomi; Ando, Masaki; Oku, Naoto

2008-10-01

The role of zinc in long-term potentiation (LTP) at hippocampal mossy fiber synapses is controversial because of the contrary results obtained when using zinc chelators. On the basis of the postulation that exogenous zinc enhances the action of zinc released from mossy fibers, mossy fiber LTP after tetanic stimulation (100 Hz, 1 sec) was checked in the presence of exogenous zinc at low micromolar concentrations. Mossy fiber LTP was significantly attenuated in the presence of 5-30 microM ZnCl(2), and the amplitude of field excitatory postsynaptic potentials 60 min after tetanic stimulation was decreased to almost the basal level. Mossy fiber LTP was also attenuated in the presence of 5 microM ZnCl(2) 5 min after tetanic stimulation. The present study is the first to demonstrate that low micromolar concentrations of zinc attenuate mossy fiber LTP. When mossy fiber LTP was induced in the presence of CaEDTA and ZnAF-2 DA, a membrane-impermeable and a membrane-permeable zinc chelator, respectively, extracellular and intracellular chelation of zinc enhanced a transient posttetanic potentiation (PTP) without altering LTP. It is likely that zinc released by tetanic stimulation is immediately taken up into the mossy fibers and attenuates mossy fiber PTP. These results suggest that attenuation of PTP rather than LTP at mossy fiber synapses is a more physiological role for endogenous zinc. Targeting molecules of zinc in mossy fiber LTP seem to be different between during and after LTP induction because of the differential synaptic activity between them. (c) 2008 Wiley-Liss, Inc.

Colchicine induced intraneuronal free zinc accumulation and dentate granule cell degeneration.

PubMed

Choi, Bo Young; Lee, Bo Eun; Kim, Jin Hee; Kim, Hyun Jung; Sohn, Min; Song, Hong Ki; Chung, Tae Nyoung; Suh, Sang Won

2014-08-01

Colchicine has been discovered to inhibit many inflammatory processes such as gout, familial Mediterranean fever, pericarditis and Behcet disease. Other than these beneficial anti-inflammatory effects, colchicine blocks microtubule-assisted axonal transport, which results in the selective loss of dentate granule cells of the hippocampus. The mechanism of the colchicine-induced dentate granule cell death and depletion of mossy fiber terminals still remains unclear. In the present study, we hypothesized that colchicine-induced dentate granule cell death may be caused by accumulation of labile intracellular zinc. 10 μg kg(-1) of colchicine was injected into the adult rat hippocampus and then brain sections were evaluated at 1 day or 1 week later. Neuronal cell death was evaluated by H&E staining or Fluoro-Jade B. Zinc accumulation and vesicular zinc were detected by N-(6-methoxy-8-quinolyl)-para-toluene sulfonamide (TSQ) staining. To test whether an extracellular zinc chelator can prevent this process, CaEDTA was injected into the hippocampus over a 5 min period with colchicine. To test whether other microtubule toxins also produce similar effects as colchicine, vincristine was injected into the hippocampus. The present study found that colchicine injection induced intracellular zinc accumulation in the dentate granule cells and depleted vesicular zinc from mossy fiber terminals. Injection of a zinc chelator, CaEDTA, did not block the zinc accumulation and neuronal death. Vincristine also produced intracellular zinc accumulation and neuronal death. These results suggest that colchicine-induced dentate granule cell death is caused by blocking axonal zinc flow and accumulation of intracellular labile zinc.

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.

Zinc triggers microglial activation

PubMed Central

Kauppinen, Tiina M.; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A.

2009-01-01

Microglia are resident immune cells of the central nervous system. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, “amoeboid” morphology and release matrix metalloproteinases, reactive oxygen species, and other pro-inflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here we show that zinc directly triggers microglial activation. Microglia transfected with an NF-kB reporter gene showed a several-fold increase in NF-kB activity in response to 30 μM zinc. Cultured mouse microglia exposed to 15 – 30 μM zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-κB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-κB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders. PMID:18509044

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

PubMed

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

2015-12-01

Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin-Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans. © 2015 Authors; published by Portland Press Limited.

Ketamine-induced behavioural and brain oxidative changes in mice: an assessment of possible beneficial effects of zinc as mono- or adjunct therapy.

PubMed

Onaolapo, Olakunle James; Ademakinwa, Olayemi Quyyom; Olalekan, Temitayo Opeyemi; Onaolapo, Adejoke Yetunde

2017-09-01

We studied the influence of zinc, haloperidol or olanzapine on neurobehaviour (open-field, radial arm maze and elevated plus maze) and brain antioxidant status in vehicle- or ketamine-treated mice, with the aim of ascertaining the potentials of zinc in counteracting ketamine's effects. Experiment 1 assessed the effects of zinc in healthy animals and the relative degrees of modulation of ketamine's effects by zinc, haloperidol or olanzapine, respectively. Experiment 2 assessed the modulation of ketamine's effects following co-administration of zinc with haloperidol or olanzapine. Male mice weighing 18-20 g each were used. Animals were pretreated with ketamine (except vehicle, zinc, haloperidol and olanzapine controls) for 10 days before commencement of 14-day treatment (day 11-24) with vehicle, zinc, haloperidol or olanzapine (alone or in combination). Ketamine injection also continued alongside zinc and/or standard drugs in the ketamine-treated groups. Zinc, haloperidol and olanzapine were administered by gavage. Treatments were given daily and behaviours assessed on days 11 and 24. On day 24, animals were sacrificed and whole brain homogenates used for estimation of glutathione, nitric oxide and malondialdehyde (MDA) levels. Ketamine increased open-field behaviours, nitric oxide and MDA levels, while it decreased working memory, social interaction and glutathione. Administration of zinc alone or in combination with haloperidol or olanzapine was associated with variable degrees of reversal of these effects. Zinc may have the potential of a possible therapeutic agent and/or adjunct in the reversal of schizophrenia-like changes in behaviour and brain oxidative status.

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

Maternal diets, nutritional status, and zinc in contemporary Mexican infants' teeth: Implications for reconstructing paleodiets.

PubMed

Dolphin, Alexis E; Goodman, Alan H

2009-11-01

Despite attempts to use zinc (Zn) concentrations in hard tissues to comment upon the degree of carnivory in past populations, zinc has yielded inconsistent trophic level effects. The question of what, if anything, zinc in human enamel reveals regarding past diets is the focus of this research. We test whether the zinc content of deciduous tooth enamel from contemporary Mexican infants varies by maternal dietary variables such as zinc intake, proportion of animal products consumed, and dietary components that are known to impact zinc absorption. Deciduous teeth were collected from former participants in a longitudinal study of maternal and infant diet and function in highland Mexico. The Zn/Ca ratios of both prenatal and postnatal regions of 37 anterior teeth representing 26 individuals were assessed via laser ablation-inductively coupled plasma-mass spectrometry. Maternal dietary data collected during lactation were not correlated with zinc levels in the early postnatal enamel of infants' teeth, which were forming at the same time. In the case of prenatal enamel, zinc values were correlated with the consumption of foods known to influence Zn bioavailability, most notably tortillas (P = 0.008; r = 0.510), but not with meat consumption. Unexpectedly, women who consumed diets with poor zinc bioavailability during pregnancy gave birth to infants whose prenatal enamel demonstrated the highest Zn/Ca ratios, possibly due to enhanced zinc absorption during pregnancy for those mothers suffering most from long-term micronutrient deficiency. These results would suggest that zinc is not a reliable trophic level indicator.

Zinc Fortification Decreases ZIP1 Gene Expression of Some Adolescent Females with Appropriate Plasma Zinc Levels

PubMed Central

Méndez, Rosa O.; Santiago, Alejandra; Yepiz-Plascencia, Gloria; Peregrino-Uriarte, Alma B.; de la Barca, Ana M. Calderón; García, Hugo S.

2014-01-01

Zinc homeostasis is achieved after intake variation by changes in the expression levels of zinc transporters. The aim of this study was to evaluate dietary intake (by 24-h recall), absorption, plasma zinc (by absorption spectrophotometry) and the expression levels (by quantitative PCR), of the transporters ZIP1 (zinc importer) and ZnT1 (zinc exporter) in peripheral white blood cells from 24 adolescent girls before and after drinking zinc-fortified milk for 27 day. Zinc intake increased (p < 0.001) from 10.5 ± 3.9 mg/day to 17.6 ± 4.4 mg/day, and its estimated absorption from 3.1 ± 1.2 to 5.3 ± 1.3 mg/day. Mean plasma zinc concentration remained unchanged (p > 0.05) near 150 µg/dL, but increased by 31 µg/dL (p < 0.05) for 6/24 adolescents (group A) and decreased by 25 µg/dL (p < 0.05) for other 6/24 adolescents (group B). Expression of ZIP1 in blood leukocytes was reduced 1.4-fold (p < 0.006) in group A, while for the expression of ZnT1 there was no difference after intervention (p = 0.39). An increase of dietary zinc after 27-days consumption of fortified-milk did not increase (p > 0.05) the plasma level of adolescent girls but for 6/24 participants from group A in spite of the formerly appropriation, which cellular zinc uptake decreased as assessed by reduction of the expression of ZIP1. PMID:24922175

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.

Serum zinc, senile plaques, and neurofibrillary tangles: findings from the Nun Study.

PubMed

Tully, C L; Snowdon, D A; Markesbery, W R

1995-11-13

Zinc appears to have a role in binding amyloid precursor protein in vitro, but it is not known whether zinc plays a role in senile plaque formation in vivo in humans. Serum zinc concentrations were available from 12 sisters who died in the Nun Study, a longitudinal study of aging and Alzheimer's disease. Fasting serum zinc concentrations, determined approximately 1 year before death, showed moderate to strong negative correlations with senile plaque counts in seven brain regions. In all brain regions combined, the age-adjusted negative correlations with serum zinc were statistically significant for total senile plaques and diffuse plaques, and suggestive for neuritic plaques. Thus serum zinc in the normal range may be associated with low senile plaque counts in the elderly.

Effect of glycation on human serum albumin-zinc interaction: a biophysical study.

PubMed

Iqbal, Sarah; Qais, Faizan Abul; Alam, Md Maroof; Naseem, Imrana

2018-05-01

Zinc deficiency is common in diabetes. However, the cause of this phenomenon is largely unknown. 80% of the absorbed zinc is transported through the blood in association with human serum albumin (HSA). Under persistent hyperglycemia, HSA frequently undergoes non-enzymatic glycation which can affect its structure and metal-binding function. Hence, in this study, we have examined the interaction of zinc with native and glycated HSA. The protein samples were incubated either in the presence or in the absence of physiologically elevated glucose concentration for 21 days. The samples were then analyzed for structural changes and zinc-binding ability using various spectrometric and calorimetric approaches. The study reveals changes in the three-dimensional structure of the protein upon glycation that cause local unfolding of the molecule. Most such regions are localized in subdomain IIA of HSA which plays a key role in zinc binding. This affects zinc interaction with HSA and could in part explain the perturbed zinc distribution in patients with hyperglycemia. The varying degree of HSA glycation in blood could explain the observed heterogeneity pertaining to zinc deficiency among people suffering from diabetes.

Cadmium-free junction fabrication process for CuInSe.sub.2 thin film solar cells

DOEpatents

Ramanathan, Kannan V.; Contreras, Miguel A.; Bhattacharya, Raghu N.; Keane, James; Noufi, Rommel

1999-01-01

The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface. A second thin film layer of semiconductor material comprising zinc oxide is then applied in two layers. The first layer comprises a thin layer of high resistivity zinc oxide. The second relatively thick layer of zinc oxide is doped to exhibit low resistivity.

[Effects of zinc deficiency in pregnancy on the mother and the newborn infant].

PubMed

Favier, A; Favier, M

1990-01-01

There seems to be a zinc deficiency during pregnancy in view of the low serum zinc levels, but especially low zinc levels in hair and leucocytes. The need for zinc supplements is still ill-defined but represents at least 5 mg per day which are not covered by the diet and taken from the maternal reserves. Therefore the risk of deficiency is real and its manifestations are numerous. There is a risk of spontaneous abortion, gravidic toxemia, treatment-resistant anemia, abnormally prolonged gestation and difficult delivery for the mother. As for the fetus, with zinc deficiency there is a risk of hypotrophism and malformations with potentialization of the teratogenic effect of alcohol and many medications. Besides, in animals, zinc deficiency during pregnancy results in late effects several months after birth: decrease immunity, learning or memory disorders. In view of all these consequences, administration of supplements is imperative and must be evaluated providing that it does not exceed 50 mg of zinc per day. Besides, it seems preferable to provide balanced multisupplements in minerals and vitamins, since supplement in iron alone results in zinc deficiency.

Zinc Bioavailability from Phytate-Rich Foods and Zinc Supplements. Modeling the Effects of Food Components with Oxygen, Nitrogen, and Sulfur Donor Ligands.

PubMed

Tang, Ning; Skibsted, Leif H

2017-10-04

Aqueous solubility of zinc phytate (K sp = (2.6 ± 0.2) × 10 -47 mol 7 /L 7 ), essential for zinc bioavailability from plant foods, was found to decrease with increasing temperature corresponding to ΔH dis of -301 ± 22 kJ/mol and ΔS dis of -1901 ± 72 J/(mol K). Binding of zinc to phytate was found to be exothermic for the stronger binding site and endothermic for the weaker binding site. The solubility of the slightly soluble zinc citrate and insoluble zinc phytate was found to be considerably enhanced by the food components with oxygen donor, nitrogen donor, and sulfur donor ligands. The driving force for the enhanced solubility is mainly due to the complex formation between zinc and the investigated food components rather than ligand exchange and ternary complex formation as revealed by quantum mechanical calculations and isothermal titration calorimetry. Histidine and citrate are promising ligands for improving zinc absorption from phytate-rich foods.