Copper deficiency and excess in infancy: developing a research agenda

Evaluation of Selected Antioxidant Parameters in Ready-to-Eat Food for Infants and Young Children

Infants and young children have diverse dietary needs, so conducting a detailed analysis of the food they consume in terms of antioxidant activity and the content of antioxidant elements is of utmost importance. The aim of the study was to assess the antioxidant properties and the content of Cu (copper), Se (selenium), and Zn (zinc) in baby products. A total of 398 samples of ready-to-eat food consumed by children were tested. To evaluate the antioxidant activity (338 samples, without dairy), the Folin-Ciocalteu method and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging test (DPPH) were employed to determine the total phenolic content (TPC). For the determination of mineral component content (398 samples), atomic absorption spectrometry (AAS) was used to analyze the levels of Cu and Zn, while inductively coupled plasma mass spectrometry (ICP-MS) was utilized for the quantification of Se. Fruit and vegetable mousses exhibited the highest average total phenolic content (TPC) and the highest percentage of free radical scavenging in the DPPH test. In terms of mineral content, the group of dairy products recorded the highest average levels of Cu and Se, while porridges contained the highest content of Zn. Notably, only organic baby food contained significantly more Zn compared to conventional food (12.2 ± 13.9 mg/kg vs. 10.7 ± 14.4 mg/kg). Ready-to-eat products designed for consumption by children provide antioxidant properties, and the presence of Zn, Cu, and Se can contribute to supporting antioxidant processes.

Copper and Zinc Content in Infant Milk Formulae Available on the Polish Market and Contribution to Dietary Intake

The inappropriate concentration of copper (Cu) and zinc (Zn) in formulae for infants can lead to abnormal micronutrient intake and adverse health outcomes. This study aimed to determine the concentration of Cu and Zn in different formulae and evaluate the Cu/Zn ratio. Besides, the daily intake (DI) of both micronutrients was estimated. Cu and Zn concentration in 103 formulae for infants, available in the Polish market, were assessed using atomic absorption spectrometry. The estimated DI was calculated from the average energy requirements for the 0-6 months aged infants. The microelement content of formulae was mostly in good agreement with that declared by the manufacturer (5-10% variations compared to the labeled values). The Cu/Zn ratio ranged from 1:8 to 1:25. The estimated DI of Cu was in the range of 0.14-1.11 mg/day. Six (6.7%) of the formulae did not meet the recommended range of Cu intake, especially during the first month of life and in the case of formulae for special medical purposes. The estimated DI of Zn varied from 2.27-11.25 mg/day. In most cases, the concentration of Cu and Zn in infant formulae was within the recommended range. It would be advisable to consider monitoring the DI of Cu and reconsider the Cu content in formulae for infants in proportion to its expected consumption.

Acute and subacute oral toxicity of copper oxide nanoparticles in female albino Wistar rats

The extensive use of copper oxide nanoparticles (CuO-NPs) in various industries and their wide range of applications have led to their accumulation in different ecological niches of the environment. This excess exposure raises the concern about its potential toxic effects on various organisms including humans. However, the hazardous potential of CuO-NPs in the literature is elusive, and it is essential to study its toxicity in different biological models. Hence, we have conducted single acute dose (2000 mg/kg) and multiple dose subacute (30, 300 and 1000 mg/kg daily for 28 days) oral toxicity studies of CuO-NPs in female albino Wistar rats following OECD guidelines 420 and 407 respectively. Blood analysis, tissue aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acetylcholinesterase, superoxide dismutase, catalase, lipid malondialdehyde and reduced glutathione assays, and histopathology of the tissues were carried out. The higher dose treatments of the acute and subacute study caused significant alterations in biochemical and antioxidant parameters of the liver, kidney and brain tissues of the rat. In addition, histopathological evaluation of these three organs of treated rats showed significantly high abnormalities in their histoarchitecture when compared to control rats. We infer from the results that the toxicity observed in the liver, kidney and brain of treated rats could be due to the increased generation of reactive oxygen species by CuO-NPs.

Wilson's Disease: Clinical Practice Guidelines of the Indian National Association for Study of the Liver, the Indian Society of Pediatric Gastroenterology, Hepatology and Nutrition, and the Movement Disorders Society of India

Clinical practice guidelines for Wilson's disease (WD) have been published by the American Association for the Study of Liver Diseases and European Association for the Study of the Liver in 2008 and 2012, respectively. Their focus was on the hepatic aspects of the disease. Recently, a position paper on pediatric WD was published by the European Society of Pediatric Gastroenterology Hepatology and Nutrition. A need was felt to harmonize guidelines for the hepatic, pediatric, and neurological aspects of the disease and contextualize them to the resource-constrained settings. Therefore, experts from national societies from India representing 3 disciplines, hepatology (Indian National Association for Study of the Liver), pediatric hepatology (Indian Society of Pediatric Gastroenterology, Hepatology and Nutrition), and neurology (Movement Disorders Society of India) got together to evolve fresh guidelines. A literature search on retrospective and prospective studies of WD using MEDLINE (PubMed) was performed. Members voted on each recommendation, using the nominal voting technique. The Grades of Recommendation, Assessment, Development and Evaluation system was used to determine the quality of evidence. Questions related to diagnostic tests, scoring system, and its modification to a version suitable for resource-constrained settings were posed. While ceruloplasmin and 24-h urine copper continue to be important, there is little role of serum copper and penicillamine challenge test in the diagnostic algorithm. A new scoring system - Modified Leipzig score has been suggested with extra points being added for family history and serum ceruloplasmin lower than 5 mg/dl. Liver dry copper estimation and penicillamine challenge test have been removed from the scoring system. Differences in pharmacological approach to neurological and hepatic disease and global monitoring scales have been included. Rising bilirubin and worsening encephalopathy are suggested as indicators predicting need for liver transplant but need to be validated. The clinical practice guidelines provide recommendations for a comprehensive management of WD which will be of value to all specialties.

Research priority setting in childhood chronic disease: a systematic review

OBJECTIVE

To evaluate research priority setting approaches in childhood chronic diseases and to describe the priorities of stakeholders including patients, caregivers/families and health professionals.

DESIGN

We conducted a systematic review of MEDLINE, Embase, PsycINFO and CINAHL from inception to 16 October 2016. Studies that elicited stakeholder priorities for paediatric chronic disease research were eligible for inclusion. Data on the prioritisation process were extracted using an appraisal checklist. Generated priorities were collated into common topic areas.

RESULTS

We identified 83 studies (n=15 722). Twenty (24%) studies involved parents/caregivers and four (5%) children. The top three health areas were cancer (11%), neurology (8%) and endocrine/metabolism (8%). Priority topic areas were treatment (78%), disease trajectory (48%), quality of life/psychosocial impact (48%), disease onset/prevention (43%), knowledge/self-management (33%), prevalence (30%), diagnostic methods (28%), access to healthcare (25%) and transition to adulthood (12%). The methods included workshops, Delphi techniques, surveys and focus groups/interviews. Specific methods for collecting and prioritising research topics were described in only 60% of studies. Most reviewed studies were conducted in high-income nations.

CONCLUSIONS

Research priority setting activities in paediatric chronic disease cover many discipline areas and have elicited a broad range of topics. However, child/caregiver involvement is uncommon, and the methods often lack clarity. A systematic and explicit process that involves patients and families in partnership may help to inform a more patient and family-relevant research agenda in paediatric chronic disease.

Umbilical Serum Copper Status and Neonatal Birth Outcomes: a Prospective Cohort Study

Our study aimed to assess the distribution of copper (Cu) in umbilical cord serum and estimated the association between umbilical serum Cu status and neonatal birth outcomes in a Chinese population. Through the Ma'anShan Birth Cohort Study, 2689 maternal-singleton pairs with detailed birth records and available serum samples were identified. The tertile levels of ln-transformed Cu were used to define low, medium, and high levels for serum Cu. The median for umbilical cord serum Cu was 298.2 μg/L with a range of 123.1-699.6 μg/L in this study population. Our study found a positive association between the concentration of serum Cu in the umbilical cord and the duration of gestation. Compared with medium Cu levels, we found that infants with low Cu levels had a significant higher risk of preterm birth (OR = 5.06, 95% CI 2.74, 9.34) and early-term birth (OR = 1.36, 95% CI 1.10, 1.69) in the crude model. We also found that infants with high Cu levels had a significant higher risk of late- or post-term birth (OR = 1.47, 95% CI 1.11, 1.95). A significant higher risk of preterm, early-term, and late- or post-term birth still remained, even after adjustment for potential confounding factors. Our findings suggested that both Cu deficiency and Cu overload had an adverse effect on neonatal birth outcomes.

Copper Supplementation in Premature Infants With Parenteral Nutrition-Associated Cholestasis

The aim of this study was to evaluate the effect of intermittent parenteral copper supplementation (IPC) on serum copper status and biochemical and hematological measures of copper toxicity and deficiency in premature infants with parenteral nutrition (PN)-associated cholestasis (PNAC). We performed a prospective nested observational study in premature infants with PNAC who received IPC after the development of PNAC. Infants with chromosomal disorders, TORCH (toxoplasmosis, parvovirus, syphilis, rubella, cytomegalovirus, herpes, human immunodeficiency virus) infection, metabolic disorder, and/or surgical abnormality of the hepatobiliary system were excluded. Serum copper concentrations were measured once every 2-4 weeks while receiving PN; 24 premature infants were studied. The mean gestational age (GA) of infants was 28.6 ± 4.7 weeks. On regression analysis, there was no significant association between IPC and serum copper concentration (coefficient 2.72, 95% CI: -27 to 32; P = .84) after controlling for GA, gender, and baseline copper intake before PNAC. There was no significant association of IPC with alanine and aspartate transaminases levels (hepatotoxicity) and platelet count, hematocrit, white blood cell count, and neutrophil count (measures of copper deficiency) after controlling for confounders. GA and postmenstrual age were independently and positively associated with serum copper concentration after controlling for confounders on regression analyses. Thus, IPC in premature infants with PNAC does not influence copper status and is not associated with biochemical and hematological measures of copper deficiency and/or toxicity. Serum copper concentration in premature infants with PNAC receiving IPC is determined by the degree of prematurity and postmenstrual age.

Copper concentrations in Egyptian infants with cholestasis: A single center study

BACKGROUND AND STUDY AIMS

Hepatobiliary cholestatic disorders produce excess copper (Cu) retention in the liver, which is toxic and may cause hepatitis, fulminant hepatic failure, cirrhosis and death. In this study, we measured hepatic Cu and tested its correlation with serum Cu (S. Cu) and serum ceruloplasmin (S. ceruloplasmin) in cholestatic infants.

PATIENTS AND METHODS

41 cholestatic infants were enrolled as cases and 11 healthy infants as control subjects. S. Cu and S. ceruloplasmin were done for all infants and hepatic Cu was measured in the liver specimen in cases.

RESULTS

Cases were 63.5% males with their age ranging between 1 and 7 months, while control subjects were 45.5% males with an age range between 3 and 18 months. Among cases, 41.5% had biliary atresia and 58.5% had intrahepatic cholestasis. Cholestatic infants had significantly higher levels of S. Cu and S. ceruloplasmin than control subjects and their hepatic Cu concentration was significantly higher than literature control. Infants with biliary atresia showed higher levels of Cu indices, with no statistical significance. Serum and hepatic Cu levels positively correlated with each other and with S. ceruloplasmin. Results of ROC curve showed that S. Cu was highly sensitive and specific for predicting hepatic Cu concentration at cut-off 181 μg/dl.

CONCLUSION

Serum and hepatic Cu concentrations were markedly elevated in patients with cholestasis and positively correlated with each other and with S. ceruloplasmin. S. Cu level can predict hepatic Cu concentration.

Wilson's Disease in Children: A Position Paper by the Hepatology Committee of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

Clinical presentations of Wilson's disease (WD) in childhood ranges from asymptomatic liver disease to cirrhosis or acute liver failure, whereas neurological and psychiatric symptoms are rare. The basic diagnostic approach includes serum ceruloplasmin and 24-hour urinary copper excretion. Final diagnosis of WD can be established using a diagnostic scoring system based on symptoms, biochemical tests assessing copper metabolism, and molecular analysis of mutations in the ATP7B gene. Pharmacological treatment is life-long and aims at removal of copper excess by chelating agents as D-penicillamine, trientine, or inhibition of intestinal copper absorption with zinc salts. Acute liver failure often requires liver transplantation. This publication aims to provide recommendations for diagnosis, treatment, and follow-up of WD in children.

METHODS

Questions addressing the diagnosis, treatment, and follow-up of WD in children were formulated by a core group of ESPGHAN members. A systematic literature search on WD using MEDLINE, EMBASE, Cochrane Database from 1990 to 2016 was performed focusing on prospective and retrospective studies in children. Quality of evidence was assessed according to the GRADE system. Expert opinion supported recommendations where the evidence was regarded as weak. The ESPGHAN core group and ESPGHAN Hepatology Committee members voted on each recommendation, using the nominal voting technique.

Copper sulphate use in South African traditional medicine

Copper (Cu) is an essential element to humans; however, exposure to elevated concentrations through occupational hazard and/or environmental means may be detrimental. This paper provides results of a cross-sectional study aimed to determine the prevalence of copper sulphate (CuSO₄) use in South African traditional medicine by traditional health practitioners (THPs) and details the use thereof. A total of 201 THPs were enrolled from two main municipal areas of KwaZulu-Natal (South Africa). Information on demographic characteristics of THPs, reasons for using or not using CuSO₄ as well as administration methods and age groups of recipients were collected. Of the 201 THPs interviewed, 145 (72 %) use CuSO₄ for healing purposes. The use of CuSO₄ was strongly associated with gender (p = 0.009) where the proportion of CuSO₄ users was higher for female than male THPs. CuSO₄ was reportedly administered to individuals of all ages, including infants and children. The main routes of administration were enema (n = 110; 76 %), oral (n = 40; 28 %) and use in bath (n = 40; 28 %). The reasons cited for use are diverse and included skin rashes (n = 43; 30 %), aches, pains and swelling (n = 38; 28 %) as well as sexually transmitted diseases (n = 28; 19 %). This study identified a high prevalence of THPs using CuSO₄ for healing purposes. These findings support the need to regulate South African traditional medicine to safeguard the user.

Metallic Profile of Whole Blood and Plasma in a Series of 99 Healthy Children

In recent years, special emphasis has been put on heavy metals. Children are very sensitive to accumulation of metals. Furthermore, as regards elements, the reference values in children are scarce in the literature as it is difficult to obtain the large quantity of blood necessary to analyze many metals by the conventional atomic absorption spectrometry technique. An inductively coupled plasma mass spectrometry (ICP-MS) procedure that uses a reduced sample of 0.3 mL whole blood or plasma is adapted to multielemental determinations. We applied a previously validated technique for adults that simultaneously quantifies 25 elements by ICP-MS in whole blood and 23 in plasma in a series of 99 healthy children ranging from under 5 years to <18 years, without exposure to metal or drug-containing metals. The aims of the study were to compare metallic concentrations according to the age among children and metallic concentration differences between children and adults. The blood and plasma pediatric metallic profile is a practical useful tool for many purposes in clinical toxicology, forensic toxicology and any cases of metal environmental exposure.

Compositional requirements of follow-up formula for use in infancy: recommendations of an international expert group coordinated by the Early Nutrition Academy

The follow-up formula (FUF) standard of Codex Alimentarius adopted in 1987 does not correspond to the recently updated Codex infant formula (IF) standard and current scientific knowledge. New Zealand proposed a revision of the FUF Codex standard and asked the non-profit Early Nutrition Academy, in collaboration with the Federation of International Societies for Paediatric Gastroenterology, Hepatology, and Nutrition (FISPGHAN), for a consultation with paediatric nutrition experts to provide scientific guidance. This global expert group strongly supports breastfeeding. FUF are considered dispensable because IF can substitute for breastfeeding throughout infancy, but FUF are widely used and thus the outdated current FUF standard should be revised. Like IF, FUF serve as breast milk substitutes; hence their marketing should respect appropriate standards. The compositional requirements for FUF for infants from 6 months onwards presented here were unanimously agreed upon. For some nutrients, the compositional requirements for FUF differ from those of IF due to differing needs with infant maturation as well as a rising contribution of an increasingly diversified diet with advancing age. FUF should be fed with adequate complementary feeding that is also appropriate for partially breastfed infants. FUF could be fed also after the age of 1 year without safety concerns, but different compositional requirements should be applied for optimal, age-adapted milk-based formulations for young children used only after the age of 1 year. This has not been considered as part of this review and should be the subject of further consideration.

Copper metabolism and pediatric cholestasis

PURPOSE OF REVIEW

Copper is an essential trace mineral but both deficiency and toxicity need to be avoided. Copper is regulated via excretion by the biliary system and caution was recommended when administered in patients with cholestasis. Recent clinical reports indicate that despite the cholestasis, copper should not be withheld from parenteral nutrition.

RECENT FINDINGS

Transporters involved in regulating copper levels have been identified. This explains the processes that regulate copper levels and the diseases that result from transporter defects. Monitoring copper ideally requires a liver biopsy but there are reports that in infants serum copper levels correlate with the liver copper. The published cautions about copper in cholestatic patients on parenteral nutrition led to the removal of copper from the solutions. Subsequently, multiple reports of clinical copper deficiency developing in these patients including infants were published. Newer literature indicates no elevation in infant copper levels despite normal copper parenteral nutrition supplementation in the presence of cholestasis.

SUMMARY

Copper is essential and levels are regulated in response to an individual's needs. The liver excretion of copper is the primary regulating method but clinically cholestasis does not result in elevated levels in infants. The best clinical approach to parenteral nutrition copper is careful monitoring even in the presence of cholestasis.

Risks and benefits of copper in light of new insights of copper homeostasis

Copper is an essential micronutrient involved in a variety of biological processes indispensable to sustain life. At the same time, it can be toxic when present in excess, the most noticeable chronic effect being liver damage. Potent, efficient regulatory mechanisms control copper absorption in the digestive tract and copper biliary excretion; absorption ranges between 12 and 60% in humans, depending on Cu intake, presence of other factors in the diet that may promote or inhibit its absorption and on the copper status of the individual. Current evidence suggests that copper deficiency may be more prevalent than previously thought, while copper toxicity is uncommon under customary daily life conditions. Menkes syndrome and Wilson disease are genetic conditions associated with severe copper deficiency and severe copper toxicity, respectively. Effects of milder degrees of copper deficiency and excess copper exposure are not well described, mainly due to lack of sensitive and specific indicators; serum copper concentration and ceruloplasmin are the most frequently used indicators, but they only detect rather intense changes of copper status. Of the many proteins assessed as potential markers of copper status the chaperone of Zn-Cu superoxide dismutase (CCS1) has yielded promising results; data on its performance under different conditions are needed to confirm its use as an indicator of early copper deficiency. Defining copper requirements and upper safe limits of consumption (UL) is a complex process since there are adverse health consequences from both copper deficiency and copper excess (U shape curve). The regulatory framework for risk assessment of essential trace elements introduced by the International Programme on Chemical Safety (IPCS) has proposed a homeostatic model to determine the Adequate Range of Oral Intake (AROI) of essential trace elements; the nadir of the resulting U shape curve serves to define the AROI. At this range of intake physiological mechanisms allow for normal homeostasis and basically, there are no detectable adverse effects. At present, Recommended Dietary Intakes (DRIs) and Adequate Intakes (AIs) are used to recommend copper intakes at different ages and life situations. Evidence obtained in humans and non-human primates presented here suggest that current copper UL should be re evaluated. Developing the scientific basis for a copper UL and evaluating the relevance of copper deficiency globally are future key challenges for copper researchers.

Copper supplementation in parenteral nutrition of cholestatic infants

BACKGROUND AND OBJECTIVES

Conventional practice is to reduce or eliminate copper (Cu) supplementation in the parenteral nutrition of infants with cholestasis because of the increased risk of hepatotoxicity. However, there are reports of Cu deficiency in cholestatic infants because of Cu reduction in their parenteral nutrition. The objectives of the present study are to determine the proportion of cholestatic infants who develop elevated serum Cu while receiving a nonreduced dose of parenteral Cu, to evaluate potential clinical factors that affect serum Cu in cholestatic infants, and to evaluate the impact of serum Cu on liver disease.

PATIENTS AND METHODS

This is a retrospective review of 28 cholestatic infants receiving 20 microg x kg(-1) x day(-1) of Cu via parenteral nutrition. Age-adjusted references were used to determine normality of serum Cu levels. Multiple linear regression analyses were performed to determine predictors of serum Cu and alanine aminotransferase (ALT).

RESULTS

Serum Cu levels were elevated in 2 infants (7%). On average, infants received 80% of their energy intake from parenteral nutrition for 3 months. Intestinal failure was present in 50% of the patients. Birth weight, gestational age, and ALT were identified as predictors of serum Cu (R2 = 0.53; P = 0.0001). Serum Cu, gestational age, and total bilirubin were associated with serum ALT (R2 = 0.43; P = 0.001).

CONCLUSIONS

Supplementation of parenteral Cu at 20 microg x kg(-1) x day(-1) does not lead to a significant increase in Cu toxicity or worsening of liver disease in cholestatic infants.

Influence of copper on early development: prenatal and postnatal considerations

Copper (Cu) is an essential nutrient whose requirement is increased during pregnancy and lactation. These represent times of critical growth and development, and the fetus and neonate are particularly vulnerable to deficiencies of this nutrient. Genetic mutations that predispose the offspring to inadequate stores of Cu can be life threatening as is observed in children with Menkes disease. During the last decade, severe Cu deficiency, once thought to be a rare condition, has been reported in the literature at an increasing frequency. Secondary Cu deficiencies can be induced by a variety of ways such as excessive zinc or iron intake, certain drugs, and bariatric surgery. Premature and low birth weight infants can be born with low Cu stores. A number of mechanisms can contribute to the teratogenicity of Cu including decreased activity of select cuproenzymes, increased oxidative stress, decreased nitric oxide availability, altered iron metabolism, abnormal extracellular matrix protein crosslinking, decreased angiogenesis and altered cell signaling among others. The brain, heart, and vessels as well as tissues such as lung, skin and hair, and systems including the skeletal, immune, and blood systems, are negatively affected by suboptimal Cu during development. Additionally, persistent structural, biochemical, and functional adverse effects in the offspring are noted even when Cu supplementation is initiated after birth, supporting the concept that adequate Cu nutriture during pregnancy and lactation is critical for normal development. Although Cu-containing IUDs are an effective method for increasing intrauterine Cu concentrations and for reducing the risk of pregnancy, high amounts of dietary Cu are not thought to represent a direct developmental risk.

Iron supplementation does not affect copper and zinc absorption in breastfed infants

BACKGROUND

Iron supplements are commonly recommended for infants but were suggested to inhibit zinc and copper absorption.

OBJECTIVE

The objective of this study was to investigate potential effects of iron supplementation, infant age, and mineral status on zinc and copper absorption in infants at 6 and 9 mo of age.

DESIGN

Twenty-five healthy breastfed term infants were recruited from a larger randomized iron supplementation trial. Six of these infants received iron supplements (1 mg . kg(-1) . d(-1)) from 4 to 9 mo, 8 were supplemented from 6 to 9 mo, and 11 received placebo only. Zinc and copper absorption was measured at 6 and 9 mo of age, using orally administered (70)Zn and (65)Cu and fecal monitoring of recovered stable isotopes.

RESULTS

Mean (+/-SD) zinc absorption was 51.9 +/- 17.9%, and mean copper absorption was 79.0 +/- 13.5%. No significant difference was observed in zinc or copper absorption between 6 and 9 mo of age. When combining all measurements, no significant effect of prior iron supplementation was observed on zinc or copper absorption. No significant correlation was observed between plasma zinc and zinc absorption or between plasma copper and copper absorption. No significant correlation was observed between erythrocyte copper-zinc-dependent superoxide dismutase activity and copper absorption.

CONCLUSIONS

The study does not support the contention that iron supplements inhibit the absorption of zinc or copper in healthy breastfed infants at 6-9 mo of age. In addition, we did not find any age-related changes in zinc or copper absorption between 6 and 9 mo of age.

Quality specifications for the determination of copper, zinc, and selenium in human serum or plasma: evaluation of an approach based on biological and analytical variation

BACKGROUND

Trace element external quality assessment schemes monitor laboratory performance and provide a stimulus for improvement in accuracy. However, monitoring of participant performance varies according to the scheme and can lead to conflicting conclusions.

METHODS

Quality specifications based on biological intra- and interindividual variability were calculated and compared to those currently used by various trace element external quality assessment schemes for plasma or serum copper, zinc, and selenium concentrations. For this purpose, we evaluated results reported by participating laboratories in different schemes, at key concentrations, using z scores.

RESULTS

Minimal quality specifications developed from the biological intra- and interindividual variability were, for Cu, +/-0.84 micromol/L or 12% of the assigned target concentration, whichever is greater; for Zn, +/-1.20 micromol/L or 15% of the assigned target concentration, whichever is greater; and for Se, +/-0.072 micromol/L or 12% of the assigned target concentration, whichever is greater. Reported performance of the participating laboratories depended on analyte, concentration, and the selected quality specification. In addition, the most commonly used methods for the determination of Cu, Zn, and Se may give different results.

CONCLUSIONS

The proposed minimal quality specifications based on biological variation are generally slightly less stringent than those currently in use, although they do not drastically change the performance evaluation in the different schemes. These specifications are a first step in the harmonization of practices among the schemes and remain to be evaluated.

Influence of cadmium and copper on tissue element levels of pregnant rats

In the current study, we examined the effects of Cd on Cd, Cu, Zn and Fe levels in placenta and maternal and fetal plasma and tissues, the placental weight, total fetal and maternal body weights, and fetal and maternal tissue weights during pregnancy. A total of 21 adult female rats were treated during gestation with drinking water containing one of the following: 70 mg/L of CdCl2, a combination of 70 mg/L of CdCl2 and 70 mg/L of CuSO4, or no addition (control). Placenta Cu and Fe levels, fetal liver and kidney Cu levels, and fetal liver tissue weights were lower in the group administered Cd than in the control group. Also, Cd levels in the placenta, maternal and fetal liver, and maternal kidney were higher in the group treated with Cd than in controls. In the group administered both Cd and Cu, fetal body and tissue weights did not change, but Cd levels in the placenta, maternal and fetal liver, and maternal kidneys were higher than in controls. Zn and Fe levels in the maternal kidney and fetal liver were also lower in this group. Cd exposure during pregnancy resulted in Cd accumulation in maternal and fetal tissues during pregnancy and a decrease in the total weight of fetuses, and the combination of Cd and Cu caused some changes in the both maternal and fetal levels of Cu, Zn, and Fe, but it did not cause changes in the total fetal body weight or the weights of individual tissues.

Effects of copper deficiency on mouse yolk sac vasculature and expression of angiogenic mediators

BACKGROUND

Cu deficiency results in embryonic defects and yolk sac (YS) vasculature abnormalities. In diverse model systems, Cu treatment modulates angiogenesis, perhaps by influencing the activity of angiogenic mediators such as vascular endothelial growth factor (VEGF). Conversely, Cu chelators can suppress angiogenesis.

METHODS

Gestation day (GD) 8.5 embryos from mice fed Cu-adequate (Cu+) or Cu-deficient (Cu-) diets were cultured in Cu+ or Cu- medium for 48 hr. Growth and development were evaluated, and YS vessel diameters were measured. Using RT-PCR and immunohistochemistry, the mRNA and protein expressions of VEGF, Flt-1, Flk-1, Angiopoietin-1 (Ang-1), and Tie-2 were analyzed.

RESULTS

Cu+/Cu+ embryos developed normally, whereas Cu-/Cu- embryos showed a high incidence of developmental anomalies. Cu-/Cu- YS had a high proportion of vessels that were large in diameter compared to the Cu+/Cu+ YS. The mRNA expression of angiogenic mediators in Cu-/Cu- YS was similar to that in Cu+/Cu+ YS. The protein expression of VEGF in the Cu-/Cu- YS without any vessel defects, and Tie-2 in the Cu-/Cu- YS with both vessel defects and blood islands was significantly lower than that in the Cu+/Cu+ YS. The protein expression of Flt-1, Flk-1 and Ang-1 was similar among groups regardless of the presence, or type, of vessel defects.

CONCLUSIONS

Results from the current study support the concept that Cu is required for the normal development of YS vasculature. Our data suggest that the impaired vascularization of Cu-deficient YS cannot be explained fully by the altered protein expression of the angiogenic growth factors reported here.

Acquisition of visuomotor abilities and intellectual quotient in children aged 4-10 years: relationship with micronutrient nutritional status

Lethargy, poor attention, and the high rate and severity of infections in malnourished children affect their educational achievement. We therefore studied the association between visuomotor abilities and intelligence quotient (IQ) and their relationship with iron, zinc, and copper. A cross-sectional study was carried out on a sample of 89 healthy children (age range, 4-10 years). Evaluations of visuomotor ability and IQ were performed with the Developmental Test of Visual Motor Integration (VMI) and the Scale for Measurement of Intelligence for children aged 3-18 years, respectively. Nutritional status was assessed using anthropometry and biochemical assessments, which included serum ferritin, zinc and copper levels, and Hb. The sample was classified as having low or normal VMI scores: 47 children (52.8%, mean age 7 +/- 1.5 years) had low VMI, and 42 (47.2%, mean age 7 +/- 2.06 years) had normal VMI. There were no statistically significant differences in socioeconomic and cultural condition between both groups. We found significantly higher serum copper and ferritin levels in normal as compared to low VMI, but we did not find any differences with zinc. IQ was significantly higher in normal vs low VMI children. The fact that children with abnormal VMI presented low mean serum copper and ferritin concentrations could indicate that copper and iron deficiencies in this sample could be related with visuomotor abilities.

Early histological and functional effects of chronic copper exposure in rat liver

Cu is an essential trace element capable of producing toxic effects in animals and man when ingested acutely or chronically in excess. Although chronic Cu exposure is increasingly recognized as a public health issue, its early effects remain largely unknown. We approached the significance of a moderate chronic Cu load in young rats to correlate early hepatic histopathological changes with functional alterations of liver cells. For this purpose, supplementation with 1,200 ppm of Cu in rat food for 16 weeks was chosen. In these conditions, Cu load elicited a significant decrease in growth curves. There were mild light microscopy alterations in Cu-treated rats, although increasing intracellular Cu storage was correlated with longer Cu exposure both by histological and biochemical measurements. Ultrastructural alterations included lysosomal inclusions as well as mitochondrial and nuclear changes. Liver perfusion studies revealed higher rates of basal O(2) consumption and colloidal carbon-induced O(2) uptake in Cu-treated rats, with enhanced carbon-induced O(2)/carbon uptake ratios and NF-kappaB DNA binding activity. These changes were time-dependent and returned to control values after 12 or 16 weeks. It is concluded that subchronic Cu loading in young rats induces early hepatic morphological changes, with enhancement in Küpffer cell-dependent respiratory burst activity and NF-kappaB DNA binding, cellular responses that may prevent or alleviate the hepatotoxicity of the metal.

Toxicity of copper intake: lipid profile, oxidative stress and susceptibility to renal dysfunction

The present study was carried out to investigate the effects of copper (Cu) intake on lipid profile, oxidative stress and tissue damage in normal and in diabetic condition. Since diabetes mellitus is a situation of high-risk susceptibility to toxic compounds, we examined potential early markers of Cu excess in diabetic animals. Male Wistar rats, at 60-days-old were divided into six groups of eight rats each. The control(C) received saline from gastric tube, the no-diabetic(Cu-10), treated with 10 mg/kg of Cu(Cu(++)-CuSO4, gastric tube), no-diabetic with Cu-60 mg/kg(Cu-60), diabetic(D), diabetic low-Cu(DCu-10) and diabetic high-Cu(DCu-60). Diabetes was induced by an ip injection of streptozotocin (60 mg/kg). After 30 days of treatments, no changes were observed in serum lactate dehydrogenase, alanine transaminase and alkaline phosphatase, indicating no adverse effects on cardiac and hepatic tissues. D-rats had glucose intolerance and dyslipidemic profile. Cholesterol and LDL-cholesterol were higher in Cu-60 and DCu-60 than in C, Cu-10 and D and DCu-10 groups respectively. Cu-60 rats had higher lipid hydroperoxide (HP) and lower superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) serum activities than C and Cu-10 rats. LH was increased and GSH-Px was decreased, while no alterations were observed in SOD and catalase in serum of DCu-60 animals. DCu-60 rats had increased urinary glucose, creatinine and albumin. In conclusion, Cu intake at high concentration induced adverse effects on lipid profile, associated with oxidative stress and diminished activities of antioxidant enzymes. Diabetic animals were more susceptible to copper toxicity. High Cu intake induced dyslipidemic profile, oxidative stress and kidney dysfunction in diabetic condition. Copper renal toxicity was associated with oxidative stress and reduction at least, one of the antioxidant enzymes.

Zinc/copper imbalance reflects immune dysfunction in human leishmaniasis: an ex vivo and in vitro study

Background

The process of elimination of intracellular pathogens, such as Leishmania, requires a Th1 type immune response, whereas a dominant Th2 response leads to exacerbated disease. Experimental human zinc deficiency decreases Th1 but not Th2 immune response. We investigated if zinc and copper levels differ in different clinical forms of leishmaniasis, and if these trace metals might be involved in the immune response towards the parasite.

Methods

Blood was collected from 31 patients with either localized cutaneous (LCL), mucosal (ML) or visceral (VL) leishmaniasis, as well as from 25 controls from endemic and non-endemic areas. Anti-Leishmania humoral and cellular immune response were evaluated by quantifying specific plasma IgG, lymphoproliferation and cytokine production, respectively. Plasma levels of Cu and Zn were quantified by atomic absorption spectrophotometry.

Results

A significant decrease in plasma Zn was observed in all three patient groups (p < 0.01 for LCL and ML, p < 0.001 for VL), as compared to controls, but only VL (7/10) and ML (1/7) patients displayed overt Zn deficiency. Plasma Cu was increased in LCL and VL (p < 0.001) but not in ML, and was strongly correlated to anti-Leishmania IgG (Spearman r = 0.65, p = 0.0028). Cu/Zn ratios were highest in patients with deficient cellular (VL<<LCL<ML) and exacerbated humoral (VL>LCL>ML) immune response. Ex vivo production of parasite-induced IFN-γ was negatively correlated to plasma Cu levels in LCL (r = -0.57, p = 0.01). In vitro, increased Cu levels inhibited IFN-γ production.

Conclusions

1. Zn deficiency in VL and ML indicate possible therapeutic administration of Zn in these severe forms of leishmaniasis. 2. Plasma Cu positively correlates to humoral immune response across patient groups. 3. Environmentally or genetically determined increases in Cu levels might augment susceptibility to infection with intracellular pathogens, by causing a decrease in IFN-γ production.