High Doses Of Zinc Research Articles

ENHANCING SPINACH (SPINACIA OLERACEA L.) SEED GERMINATION, LEAF BIOMASS PRODUCTION UNDER SALINE WATER STRESS: THE IMPLICATIONS OF ZINC AND COW MANURE

Plant growth and productivity is restricted due to significant influence of salt stress on the essential physiological processes. Zinc supplementation holds promise as a technique to improve the resilience under salt stress. An open field experiment was conducted to assess the leaf growth parameters of spinach (Spinacia oleracea) including seed germination, plant area, leaf area, length, width, leaf fresh weight as well as dry weight, and Number of leaves per plant. Spinach plants were irrigated with a defined electrical conductivity (EC) level of 4.16 dSm-1 in clay loam, non-saline soil. Cow manure, a form of organic waste rich in macronutrients and micronutrients was also investigated. This study focuses on examining the response of zinc and cow manure on spinach growth under salinity stress. Salinity stress resulted in reduction in seed germination, leaf area, width, length, leaf fresh and dry weight, with no significant effect on the number of leaves. High doses of zinc and cow manure (0.20g Zinc+ 150g Cow Manure + Salinity) meaningfully enhanced performance by increasing seed germination by 15-20%, leaf area 130 cm2, length 8.41 cm, width 4.8 cm , leaf fresh 0.67g and leaf dry weight 0.51g but didn’t affect the number of leaves. Overall, our results demonstrate that the application of zinc and cow manure induced resistance to salinity stress and impacts positively on Spinach growth. Future research can focus on how zinc affects enzymatic activities and various mechanisms under salt stress.

Short-term supplementation of zinc nanoparticles in weaned piglets affects zinc bioaccumulation and carcass classification

High doses of zinc have been used as a prevention against weaned piglets' diarrhea for many years. Nevertheless, since 2022 high doses of zinc oxide have been banned in EU. Currently, there are several studies about the potential of zinc nanoparticles in lower doses which could maintain a preventive effect. Several concerns about nanoparticles' toxicity and bioaccumulation have been raised in many other fields of research. The aim of this short follow-up study is focused on the impact of zinc nanoparticles used as a prevention of diarrhea for weaned piglets, on the classification of slaughtered pigs’ carcasses and on zinc retention in muscle tissue. Seventy piglets (10 groups of 7 piglets) were fed a standard diet. The treated groups’ diets were supplemented with zinc oxide (ZnO), and phosphate-based nanoparticles: spherical- shaped type A (ZnA) and irregular-shaped: type C (ZnC), at the doses of 500, 1000 and 2000 mg Zn equivalent per kilogram of diet. The control group´s diet was not treated with zinc in any form. The feed experiment started when the piglets were 28 days old and lasted for 10 days. Experimental animals were grown to the final weight 120 ± 10 kg and slaughtered in a slaughterhouse. The pig carcasses were evaluated according to S/EUROP standards: the pigs’ weight, back fat thickness and lean meat content were monitored. Moreover, zinc concentrations in M. longissimus dorsi et thoracis were analyzed. The results have not proved significant changes in S/EUROP standard classification and zinc bioaccumulation in muscle tissue. This follow-up experiment was carried out as part of maintaining a precautionary approach to the use the nanoparticles in piglet fattening. In our study we did not confirm their effect on the assessment of carcass classification and their bioaccumulation in muscle tissue.

Effects of dietary zinc chloride hydroxide and zinc methionine on the immune system and blood profile of healthy adult horses and ponies

ABSTRACT The effects of dietary zinc on the immune function of equines have not been evaluated in detail so far. In the present study, eight healthy adult ponies and two healthy adult horses were fed a diet supplemented with either zinc chloride hydroxide or zinc methionine in six feeding periods of four weeks each (according to maintenance zinc requirement, 120 mg zinc/kg dry matter, and 240 mg zinc/kg dry matter, for both dietary zinc supplements, respectively). All animals received the six diets, with increasing amounts of zinc chloride hydroxide in the feeding periods 1–3, and with increasing amounts of zinc methionine in the feeding periods 4–6. At the end of each feeding period, blood samples were collected for a blood profile and the measurement of selected immune variables. Increasing dietary zinc chloride hydroxide doses increased the glutathione concentrations in the erythrocyte concentrate and the glutathione peroxidase activity in the erythrocyte lysate, decreased the numbers of total leukocytes and granulocytes in the blood, and also decreased the interleukin-2 concentrations in the plasma of the animals. The dietary supplementation of increasing doses of zinc methionine enhanced the mitogen-stimulated proliferative activity of peripheral blood mononuclear cells, and decreased the glutathione concentrations in the erythrocyte concentrate and the glutathione peroxidase activity in the plasma of the animals. The percentage of blood monocytes with oxidative burst after in vitro stimulation with E. coli decreased with increasing dietary zinc concentrations, independently of the zinc compound used. The blood profile demonstrated effects of the zinc supplements on the red blood cells and the bilirubin metabolism of the horses and ponies, which require further investigation. Overall, high doses of dietary zinc modulate the equine immune system, for the most part also depending on the zinc compound used.

Effect of Zinc drug on amino acid concentration in liver of white mice, Mus musculus

Zinc is one of the essential trace elements, it plays a key role in many biochemical and functional processes. It is less harmful than many other minerals, in the case of exposure to high doses of zinc, poisoning occurs, and this poisoning may mostly result from the accidental ingestion of household products containing zinc or nutritional supplements, this study was conducted to find out the effects of zinc on the concentration of amino acid. A total of 30 adult white mouse males were taken and divided into three groups; the first group (control) of 10 mice taken with distilled water for 30 days, the second group includes 10 mice that were dose with Zn drug concentration of 50 mg/kg/day for 30 days, the third group includes 10 mice that were dose with Zn drug 100 mg/kg/day for 30 days. In the current study (18) amino acid was recorded in the liver of adult white mouse males as follow: asparagine (Asn), serine (Ser), glutamine (Glu), glycine (Gly), threonine (Thr), histidine (His), citrulline (Cit), alanine (Ala), proline (Pro), taurine (Tau), arginine (Arg), tyrosine (Tyr), valine (Val), methionine (Met), isoleucine (Ile), leucine (Leu), phenylalanine (Phe) and lysine (Lys). Statistical analysis showed high significant differences in the concentration of amino acids between the two groups of the zinc-treated experiment with a concentration (50 and 100) mg/kg/day and control group, as well as significant differences between the two groups of the zinc treatment experiment with a concentration of (50 and 100) mg/kg/day.

247 Nutritional Interventions: Our Experiences from the Field

Abstract Dealing with E. coli in the early post-weaning period has been an ongoing theme in the swine industry since many years. Many strategies have been putted in place in order to reduce the issue. Knowledge in nutrition and use of specific feed additive have for sure led the way as solution to overcome those enteric challenge. We also saw a shift over the last 10-15 years for an increase in wean age in order to have a more robust and well-developed pig at weaning. Despite those improvements, use of pharmacological dose of zinc in the early phase post-weaning has remain a key strategy to control E. coli. On the other hand, in some case, efficacy of the historical pharmacological dose of zinc of 2000 to 25000 ppm for the first 2-3 weeks post-weaning seem to be not sufficient to control E. coli challenge. Higher dose and/or use over an extended period of time seem to be more common those days. The reason why we are talking more and more about zinc oxide is that many countries, mostly in Europe, have restricted/banded to use of high dose of zinc in any diet for pig. Limit have now been set at level around 150 ppm. Concern about environmental impact, but mostly about link with antibiotic resistance have been the main concern toward the ban of pharmacological dose of zinc. Canada feed regulations is under review and expectation is that we will also have a ban on high dose of zinc. With that in mind, our group have worked toward finding way to successfully feeding pig with low level of zinc and try to limit the impact of E. coli. We have run multiple research projects throughout the year and we are still conducting project that focus on feeding low level of zinc. Our belief and observation are that the success rely on a broader approach vs the use of single additive to replace the zinc oxide. We are talking about nutritional concept that include a complete review of how we approach the formulation of the diets for nursery pigs. Energy and protein level, use of fiber, specific feed additive, feed and water acidification are some of the strategies that need to be reviewed and evaluated in order to have a complete solution and to ensure better rate of success. The presentation will cover our experience throughout the last 10 years with the change that we implemented and that seem to allow for being successful in feeding pig in nursery with lower zinc oxide level.

Long-term Outcomes of Adding Lutein/Zeaxanthin and ω-3 Fatty Acids to the AREDS Supplements on Age-Related Macular Degeneration Progression

After the Age-Related Eye Disease Study 2 (AREDS2) study, the beta carotene component was replaced by lutein/zeaxanthin for the development of the revised AREDS supplement. However, it is unknown if the increased risk of lung cancer observed in those assigned beta carotene persists beyond the conclusion of the AREDS2 trial and if there is a benefit of adding lutein/zeaxanthin to the original AREDS supplement that can be observed with long-term follow-up. To assess 10-year risk of developing lung cancer and late age-related macular degeneration (AMD). This was a multicenter epidemiologic follow-up study of the AREDS2 clinical trial, conducted from December 1, 2012, to December 31, 2018. Included in the analysis were participants with bilateral or unilateral intermediate AMD for an additional 5 years after clinical trial. Eyes/participants were censored at the time of late AMD development, death, or loss to follow-up. Data were analyzed from November 2019 to March 2022. During the clinical trial, participants were randomly assigned primarily to lutein/zeaxanthin and/or ω-3 fatty acids or placebo and secondarily to no beta carotene vs beta carotene and low vs high doses of zinc. In the epidemiologic follow-up study, all participants received AREDS2 supplements with lutein/zeaxanthin, vitamins C and E, and zinc plus copper. Outcomes were assessed at 6-month telephone calls. Analyses of AMD progression and lung cancer development were conducted using proportional hazards regression and logistic regression, respectively. Self-reported lung cancer and late AMD validated with medical records. This study included 3882 participants (mean [SD] baseline age, 72.0 [7.7] years; 2240 women [57.7%]) and 6351 eyes. At 10 years, the odds ratio (OR) of having lung cancer was 1.82 (95% CI, 1.06-3.12; P = .02) for those randomly assigned to beta carotene and 1.15 (95% CI, 0.79-1.66; P = .46) for lutein/zeaxanthin. The hazard ratio (HR) for progression to late AMD comparing lutein/zeaxanthin with no lutein/zeaxanthin was 0.91 (95% CI, 0.84-0.99; P = .02) and comparing ω-3 fatty acids with no ω-3 fatty acids was 1.01 (95% CI, 0.93-1.09; P = .91). When the lutein/zeaxanthin main effects analysis was restricted to those randomly assigned to beta carotene, the HR was 0.80 (95% CI, 0.68-0.92; P = .002). A direct analysis of lutein/zeaxanthin vs beta carotene showed the HR for late AMD was 0.85 (95% CI, 0.73-0.98; P = .02). The HR for low vs high zinc was 1.04 (95% CI, 0.94-1.14; P = .49), and the HR for no beta carotene vs beta carotene was 1.04 (95% CI, 0.94-1.15; P = .48). Results of this long-term epidemiologic follow-up study of the AREDS2 cohort suggest that lutein/zeaxanthin was an appropriate replacement for beta carotene in AREDS2 supplements. Beta carotene usage nearly doubled the risk of lung cancer, whereas there was no statistically significant increased risk with lutein/zeaxanthin. When compared with beta carotene, lutein/zeaxanthin had a potential beneficial association with late AMD progression.

Study of the Effect of Selective Media with High Doses of Zinc on Regeneration Ability and Rutin Accumulation in Common Buckwheat In Vitro

Biotechnological methods are widely used in modern common buckwheat (Fagopyrum esculentum Moench) studies, constitute an effective tool to create the best agronomic traits of the crop, and can also be used to breed forms, resistant to heavy metal ion toxicity, which is important in the environment of constantly growing anthropogenic pressure on ecosystems. The studied high concentrations of zinc salts (808–1313 mg L−1) in the nutrient medium in vitro had an inhibitory effect on buckwheat, which was manifested by a decrease in values of its morphological indicators. Ion stress had an adverse effect on 7–9% of plants from their total number, indicating high plasticity and resistance of F. esculentum to highly toxic doses of zinc. The stress state of F. esculentum significantly increases the production of flavonoid compounds, including rutin, in plant cells, which is used in biotechnology to assess and obtain buckwheat forms of high flavonoid induction capacity. The processes of rutin biosynthesis were most intense in test-tube plants of the Izumrud × Inzerskaya hybrid obtained after exposure to high doses of zinc 1010–1212 mg L−1. F. esculentum genotypes obtained using selective backgrounds with high zinc concentrations are promising biosystems for synthesis of rutin, valuable for pharmacology and medicine.

Effects of zinc supplementation on metabolic status in patients with metabolic syndrome

Being a micronutrient, zinc involves in numerous biochemical reactions as a principle component or catalyzing enzymes for proper propagation of enzymatic function. Metabolic syndrome (MS) has been increasingly reported to be associated with derangement of the intrinsic physiological functions including suppression of micronutrient functionality and concentration. During the COVID-19 outbreak, a relatively high dose of zinc has been prescribed by private clinics for non-infected/high-risk subjects;who include patients with MS on polytherapy. We aimed to investigate the effect of 50mg-zinc tablet administered as an add-on therapy for three months to patients with MS. According to our health care providers;MS patients undergo an annual quadruple check by measuring the routine biochemical factors (serum glucose, and lipid profile), blood pressure, and body mass indices. Data were collected before and after zinc administration and statistically analyzed in comparison to the control non-zinc user group. The results confirmed that zinc positively improved measured parameters by significantly reducing blood pressure, serum glucose, and lipid indices;together with slightly modulating body mass indices. To confirm that the quality of the zinc tablet provided by the supplier, plasma zinc concentrations were also measured before and after therapy. In conclusion, zinc supplementation could be part of the therapy for metabolic diseases and we do advise intermittent zinc use in such patients.

Selection of copper and zinc dosages in pig diets based on the mutual benefit of animal growth and environmental protection

Dietary copper and zinc additives facilitate the growth and development of animals, but heavy metal in feces threatens the ecological environment, and balance is the key to solving the problem. In this study, a trial of 2000 pigs (early nursery, 9–15 kg; late nursery, 15–25 kg; grower: 25–60 kg) was conducted to analyze the effects of different diets (gradient dosage of copper and zinc additives) on growth performance, antioxidant performance, immune function, and fecal heavy metal excretion of piglets and growing pigs. Although no significant differences were observed in average daily gain (ADG) and average daily feed intake (ADFI) between treatments during the entire nursery-grower period, the addition of appropriate high doses of copper and zinc to the diet had a beneficial effect on the antioxidant status and immune function of weaned piglets. Especially at early nursery, compared with the low-copper group (5 mg/kg Cu), the high-copper group (120 mg/kg Cu) could significantly increase the peroxidase (POD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC), catalase (CAT) and copper/zinc superoxide dismutase (Cu/Zn-SOD), cortisol in the serum. Moreover, the addition of zinc and copper in the diet not only increased the concentration of corresponding trace elements in the serum, but also affected the concentration of other trace elements in the serum. The reduction of copper and zinc content in the diet contributed to reducing the copper and zinc content in feces. In conclusion, we have formulated the mutual benefit dosages of copper and zinc (9–15 kg: 5 mg/kg Cu and 50 mg/kg Zn; 15–25 kg: 4 mg/kg Cu and 50 mg/kg Zn; 25–60 kg: 4 mg/kg Cu and 10 mg/kg Zn) for weaning piglets and growing pigs, which would help ensure the healthy growth of animals and reduce environmental heavy metal residues. CapsuleThis study developed a mutually beneficial dose of copper and zinc in pig diets, which promotes animal growth and protects the environment.

Response of Potato to Zinc Application in Eastern Indo-Gangetic Plains of India

A field experiment was conducted during two consecutive years of 2015-16 and 2016-17 at Central Potato Research Station, Patna with objective to evaluate theresponse of zinc on potato tuber yield. Significant effect of zinc application was not noticed on plant emergence and plant height of crop at 30 days after planting. However, higher plant height was recorded in the plot which received the zinc as compare to without zinc application. Significant difference in plant height was observed at later stages of crop due to application of zinc at the rate of 6.0 kg/ha along with recommended dose of fertilizers. Similarly, dry matter yield of potato tubers was also recorded consequently higher due to application of higher doses of zinc. Tuber grades of 0-25g and 25-50g were found non-significant irrespective of doses of zinc application in potato. Significant variation in medium and large size tuber yield were recorded due to application of zinc @ 6 kg/ha over without zinc application. About 18.1% increase in marketable tuber yield of potato was found due to application of zinc @ 6.0 kg/ha as compare to without zinc application. About11.3% and 13.7% increase in the total tuber yield of potato was observed due to application of zinc @ 4.5 and 6.0 kg/ha, respectively over without zinc application. However, no significant variation in pooled yield was found with application of zinc up to 3.0 kg/ha over without zinc application. The highest net return (Rs. 36.0×103/ha) and net benefit cost ratio (2.52) was recorded due to application of zinc @ 6.0 kg/ha as compare to without zinc. Application of zinc @ 6.0 kg/ha along with recommended dose of NPK may be found more beneficial for potato cultivation under Eastern Indo-Gangetic plains of India.

Zinc-related Treatments Combined with Chloroquine and Gemcitabine for Treating Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers, with a 10% 5-year survival rate. A prominent issue with the treatment mainly used today, gemcitabine, is that it is unable to penetrate the stroma around the pancreatic cancer tumor. The stroma is a dense network of cells that promotes cancer development and metastasis and creates difficulty for chemotherapy treatments to be delivered effectively to the tumor. Targeting the pathways responsible for both the stroma (namely the Hedgehog signaling pathway) and the tumor (the Ras/MAPK pathway) could potentially lead to more effective treatments. The dysregulation of zinc has been implicated in disease progression through these pathways, however its exact effect is unclear. TPEN is a metal ion chelator that is able to induce zinc deficiency. We hypothesized that if various dosages of TPEN and zinc are used in combination with Chloroquine and Gemcitabine, then combinations of medium to high doses of zinc, Chloroquine, and Gemcitabine will be the most effective at reducing cell proliferation. Several treatment combinations were created in a drug matrix and tested using a cell proliferation assay. To mimic the stroma-tumor interaction that would occur in vivo, we took the conditioned medium from pancreatic cancer associated fibroblasts (mCAF) and cultured pancreatic cancer cells (PANC-1). The results showed that while TPEN was able to significantly lower cell proliferation, it was not more effective than the current treatment. However, when combined with Chloroquine and Gemcitabine, zinc and TPEN both significantly lowered cell proliferation compared to Gemcitabine, suggesting a synergistic effect that resulted in a more cytotoxic treatment. Further research and clinical trials on this topic are needed to determine whether this could be a viable treatment for pancreatic cancer. This repurposed treatment could potentially increase survival rates and become a more affordable alternative to novel drug development.

Tolerance and translocation of heavy metals in young grapevine (Vitis vinifera) grown in sandy acidic soil with interaction of high doses of copper and zinc

Vineyard soils may have high levels of copper due to frequent applications of Bordeaux mixture for the control of fungal diseases. Therefore, many winegrowers have used zinc-based fungicides instead of copper-based fungicides, resulting in high levels of Cu and Zn in vineyard soils. The aim of the study was to evaluate the tolerance of young grapevines grown in soil with interaction of high contents of Cu and Zn, and the translocation of these heavy metals from roots to shoots. We collected soil of a natural field of Rio Grande do Sul, the southernmost state of Brazil. Soil treatments were addition of 0, 30, and 60mg Cu kg−1, and addition of 0, 15, 30, 60, 120, and 180mg Zn kg−1 for each copper dose. A seedling of grapevine per pot was grown for 60days. After that, we measured root and shoot dry matter, Cu and Zn content in roots and shoots, chlorophyll a fluorescence, photosynthetic pigments, and peroxidase and superoxide dismutase activity. Young grapevines showed tolerance mechanisms to high concentrations of Cu and Zn by retaining these metals in the roots, decreasing translocation to the shoots. However, at the highest doses of Cu and Zn, we observed decrease in plant growth and in photochemical efficiency associated with the decrease in photosynthetic pigment content. Furthermore, the activity of antioxidant enzymes increased in intermediate doses of Zn, which indicates activation of the antioxidant system. However, the stress condition in treatments with high levels of Cu and Zn was not reversed.

The content of polyphenols and chosen heavy metals in faba bean (Faba vulgaris Moench) relating to different doses of zinc application

We investigated the impact of zinc on chosen heavy metals contents (Cu, Zn, Co, Cd, Pb, Cr, Ni) and polyphenols content and antioxidant capacity of chosen legume. Used soil was from Cakajovce locality (located in Nitra upland) with the neutral soil reaction suitable for the legume cultivation. Determined Cd content as well as Pb content in the soil was on the level of critical value given for the relationship between soil and plant. The values of both elements were far below threshold values proposed by European Commission. In experiment we used two cultivars of fababean - Saturn, Zobor. Seeds of fababean were harvested in milk ripeness. The different high doses of zinc (as ZnSO4.7H2O) were applied into the uncontaminated soil in model conditions. The strong statistical relationship between added Zn content in the soil and in seeds of both faba bean cultivars as well as was the total polyphenols content and the total antioxidant capacity values was confirmed. In all variants the determined Zn amount was below (Saturn) or slightly above (Zobor) the hygienic limit given by the legislative. On the other hand faba bean of both cultivars accumulated high amounts of Pb and Cd - in all variants higher than hygienic limits. The contents of all other heavy metals (Ni, Co, Cr, Cu) were lower than hygienic limits. The polyphenols content ranged from 2208 to 4622 milligrams per kilogram of fresh sample calculated as gallic acid equivalents. Faba bean shows a very small antioxidant capacity - 4.66 - 5.71% of DPPH inhibition.

English

The objective of this work was to study combinations of high doses of boron (B) and zinc (Zn) in the recoating of perennial soybean seeds, in order to provide these nutrients to the future plants. The physical, physiological and nutritional characteristics of the coated seeds and initial development of plants in a greenhouse were evaluated. Tests carried out in the laboratory were conducted in a completely randomized design, and the experiments completed in a greenhouse were a randomized block design. The coating with the dose 0.8 kg of H 3 BO 3 + 0.8 kg of ZnSO 4 . kg-¹ of seeds provides the best quality coating. The combination of B and Zn in seed coating reduces the production of shoot dry matter, while the other treatments do not affect the growth variables of the plants. Plants absorb and accumulate the micronutrients added to the coating of the seeds. Key words : Micronutrients, coater, soybean, seeds.

Physiological and nutritional status of black oat (Avena strigosa Schreb.) grown in soil with interaction of high doses of copper and zinc

Vineyard sandy acid soils from South Brazil have experienced heavy metal contamination due to replacement of copper (Cu)-based by zinc (Zn)-based products to control foliar diseases. Thus, we evaluate physiological and nutritional status of black oat (Avena strigosa Schreb.), a common interrow crop in vineyards from this region. Soil was collected in a natural field from Santana do Livramento, in Rio Grande do Sul, the southernmost state of Brazil. Black oat was cultivated for 30 days in a greenhouse with application of 0, 30, and 60 mg Cu kg−1 combined with 0, 15, 30, 60, 120, and 180 mg Zn kg−1. After the trial period, dry matter accumulation of roots and shoots, Cu and Zn contents in roots and shoots, chlorophyll a fluorescence, photosynthetic pigments and catalase (CAT, EC 1.11.1.6) and peroxidase (POD, EC 1.11.1.7) activity were determined. Cu and Zn toxicity was evidenced by the decrease in plant growth of black oat as well as by the decrease of photochemical efficiency associated with the decrease in photosynthetic pigment content, especially with the highest doses of Cu and Zn. Furthermore, the activity of antioxidant enzymes (CAT and POD) was increased in intermediate doses of Zn, indicating the activation of the antioxidant system, but the stress condition in treatments with high levels of Cu and Zn was not reversed.

Copper deficiency mimicking myelodysplastic syndrome.

Copper is an essential element for all living organisms, because it has key activities in the metabolic enzymes such as cytochrome oxidase and superoxide dismutase, and in the proteins essential for iron homeostasis such as ceruloplasmin and hephaestin. In humans, the daily copper requirement is low, therefore copper deficiency is not so frequently a condition. However, we should be aware that copper deficiency can cause hematological abnormalities and sometimes it may masquerade as a myelodysplastic syndrome (MDS). Copper deficiency is mainly associated with the conditions, such as gastric and bariatric surgery, parenteral hyperalimentation, enteroparthies with loss of proteins, hypoproteinemic status such as celiac disease, complications due to therapy with high doses of zinc and penicillamine, and chronic use of proton pump inhibitors. Copper deficiency can be associated with hyperzinchemia; in some cases, this condition could be a consequence of possible use of zinc based denture adhesives creams. The copper deficiency may also be the result of an inherited disorder, such as the Menkes disease.

RESPOSTA DE PORTA-ENXERTOS DE CARAMBOLEIRA À ADUBAÇÃO COM ZINCO

RESUMO Apesar de ser amplamente cultivada no Estado de São Paulo, na literatura, há poucas informações sobre os efeitos da adubação e da nutrição em porta-enxertos de caramboleira. O trabalho teve como objetivo avaliar o crescimento das plantas e o acúmulo de Zn em porta-enxertos de caramboleira, submetidos a diferentes doses de zinco. O trabalho foi desenvolvido entre os meses de setembro de 2012 e fevereiro de 2013, em viveiro comercial de produção de mudas, localizado em Taquaritinga-SP. O delineamento foi em blocos casualizados, com cinco doses de zinco: zero; 2,0; 4,0; 6,0 e 8,0 mg dm-3 de Zn, quatro repetições e três plantas por parcela. Os porta-enxertos empregados no experimento estavam com um ano e dois meses de idade e foram cultivados em sacos de polietileno, com casca de pínus como substrato. Aos 170 dias após a aplicação do zinco, avaliaram-se: altura das plantas, diâmetro do caule, número de folhas, massa seca da parte aérea, das raízes e total. A concentração de zinco nas raízes e na parte aérea foi determinada e, em seguida, calculou-se o acúmulo de Zn nas diferentes partes da planta. O zinco influenciou na altura de plantas, diâmetro caulinar, emissão de folhas, acúmulo de massa seca da parte aérea, raízes e total. O maior desenvolvimento dos porta-enxertos de caramboleira esteve associado à dose entre 3,1 e 3,8 mg dm-3 de Zn. Doses elevadas de zinco prejudicam o crescimento e o acúmulo do micronutriente nos porta-enxertos de caramboleira.

High dietary zinc supplementation increases the occurrence of tetracycline and sulfonamide resistance genes in the intestine of weaned pigs

BackgroundDietary zinc oxide is used in pig nutrition to combat post weaning diarrhoea. Recent data suggests that high doses (2.5 g/kg feed) increase the bacterial antibiotic resistance development in weaned pigs. Therefore, the aim of this study was to investigate the development of enterobacterial antibiotic resistance genes in the intestinal tract of weaned pigs.FindingsWeaned pigs were fed diets for 4 weeks containing 57 (low), 164 (intermediate) or 2425 (high) mg kg−1 analytical grade ZnO. DNA extracts from stomach, mid-jejunum, terminal ileum and colon ascendens were amplified by qPCR assays to quantify copy numbers for the tetracycline (tetA) and sulfonamide (sul1) resistance genes in Gram-negative bacteria. Overall, the combined data (n = 336) showed that copy numbers for tetracycline and sulfonamide resistance genes were significantly increased in the high zinc treatment compared to the low (tetA: p value < 10−6; sul1: p value = 1 × 10−5) or intermediate (tetA: P < 1.6 × 10−4; sul1: P = 3.2 × 10−4) zinc treatment. Regarding the time dependent development, no treatment effects were seen 1 week after weaning, but significant differences between high and low/intermediate zinc treatments evolved 2 weeks after weaning. The increased number of tetA and sul1 copies was not confined to the hind gut, but was already present in stomach contents.ConclusionsThe results of this study suggest that the use of high doses of dietary zinc beyond 2 weeks after weaning should be avoided in pigs due to the possible increase of antibiotic resistance in Gram-negative bacteria.Electronic supplementary materialThe online version of this article (doi:10.1186/s13099-015-0071-3) contains supplementary material, which is available to authorized users.

The risk of copper deficiency in patients prescribed zinc supplements

AimsIn high doses zinc may cause copper deficiency, a diagnosis that is often missed resulting in anaemia, neutropenia and irreversible neurological symptoms. The aim of this study was to assess...

Trace element supplementation in hemodialysis patients: a randomized controlled trial.

BackgroundPeople with kidney failure are often deficient in zinc and selenium, but little is known about the optimal way to correct such deficiency.MethodsWe did a double-blind randomized trial evaluating the effects of zinc (Zn), selenium (Se) and vitamin E added to the standard oral renal vitamin supplement (B and C vitamins) among hemodialysis patients in Alberta, Canada. We evaluated the effect of two daily doses of the new supplement (medium dose: 50 mg Zn, 75 mcg Se, 250 IU vitamin E; low dose: 25 mg Zn, 50 mcg Se, 250 IU vitamin E) compared to the standard supplement on blood concentrations of Se and Zn at 90 days (primary outcome) and 180 days (secondary outcome) as well as safety outcomes.ResultsWe enrolled 150 participants. The proportion of participants with low zinc status (blood level <815 ug/L) did not differ between the control group and the two intervention groups at 90 days (control 23.9% vs combined intervention groups 23.9%, P > 0.99) or 180 days (18.6% vs 28.2%, P = 0.24). The proportion with low selenium status (blood level <121 ug/L) was similar for controls and the combined intervention groups at 90 days (32.6 vs 19.6%, P = 0.09) and 180 days (34.9% vs 23.5%, P = 0.17). There were no significant differences in the risk of adverse events between the groups.ConclusionsSupplementation with low or medium doses of zinc and selenium did not correct low zinc or selenium status in hemodialysis patients. Future studies should consider higher doses of zinc (≥75 mg/d) and selenium (≥100 mcg/d) with the standard supplement.Trial registrationRegistered with ClinicalTrials.gov (NCT01473914)Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-015-0042-4) contains supplementary material, which is available to authorized users.