Biomarkers of iron status and trace elements in welders

Iron status was studied in 137 welders exposed to a geometric mean (GM) air concentration of 214 μg/m³ (range 1–3230) of manganese (Mn), in 137 referents and in 34 former welders. The GM concentrations of S-ferritin were 119 (3–1498), 112 (9–1277) and 98 (12–989) μg/L (p = 0.24) in the three groups, respectively. Also the GM concentrations of S-hepcidin were not significantly different between the groups (8.4 μg/L (2.8–117); 6.6 μg/L (1.8–100); 6.5 μg/L (1.2–22)) (p = 0.22). Multiple linear regression analysis including all welders and referents showed an increase in the concentration of S-ferritin associated with having serum carbohydrate deficient transferrin (S-CDT) above the upper reference limit of ≥1.7%, indicating high alcohol consumption. Serum C-reactive protein was not associated with exposure as welders, but an association with S-ferritin was shown. The GM S-ferritin concentrations among all welders and referents with S-CDT ≥ 1.7% were 157 μg/L (95% CI 113–218) as compared to 104 μg/L (95% CI 94–116) (p = 0.02) in those with S-CDT < 1.7%. The GM concentrations of Mn in biological fluids were higher in the welders as compared to the referents, while S-Fe, S-Co and B-Co were statistically significantly lower. This could suggest a competitive inhibition from Mn on the uptake of Fe and Co. Increasing concentrations of S-CDT was associated with higher S-Mn, S-Fe and B-Co in the multiple linear regression analysis. The association between S-CDT and S-Fe remained when all subjects with high S-CDT (≥1.7%) were excluded, suggesting increased uptake of Fe even at lower alcohol consumption.     

A neutron activation technique for manganese measurements in humans

Manganese (Mn) is an essential element for humans, animals, and plants and is required for growth, development, and maintenance of health. Studies show that Mn metabolism is similar to that of iron, therefore, increased Mn levels in humans could interfere with the absorption of dietary iron leading to anemia. Also, excess exposure to Mn dust, leads to nervous system disorders similar to Parkinson's disease. Higher exposure to Mn is essentially related to industrial pollution. Thus, there is a benefit in developing a clean non-invasive technique for monitoring such increased levels of Mn in order to understand the risk of disease and development of appropriate treatments.To this end, the feasibility of Mn measurements with their minimum detection limits (MDL) has been reported earlier from the McMaster group. This work presents improvement to Mn assessment using an upgraded system and optimized times of irradiation and counting for induced gamma activity of Mn. The technique utilizes the high proton current Tandetron accelerator producing neutrons via the ⁷Li(p,n)⁷Be reaction at McMaster University and an array of nine NaI (Tl) detectors in a 4π geometry for delayed counting of gamma rays. The neutron irradiation of a set of phantoms was performed with protocols having different proton energy, current and time of irradiation. The improved MDLs estimated using the upgraded set up and constrained timings are reported as 0.67 μgMn/gCa for 2.3 MeV protons and 0.71 μgMn/gCa for 2.0 MeV protons. These are a factor of about 2.3 times better than previous measurements done at McMaster University using the in vivo set-up. Also, because of lower dose-equivalent and a relatively close MDL, the combination of: 2.0 MeV; 300 μA; 3 min protocol is recommended as compared to 2.3 MeV; 400 μA; 45 s protocol for further measurements of Mn in vivo.     

Manganese species from human serum,cerebrospinal fluid analyzed by size exclusion chromatography-, capillary electrophoresis coupled to inductively coupled plasma mass spectrometry

Manganese (Mn) at high concentrations can have adverse effects on health, mainly because of its toxicity to the central nervous system. Health impacts of Mn are known mostly from occupational health studies, but the exact mechanisms how Mn, being bound to transferrin (TF) in the blood, enters the brain – are unknown. Mn speciation at the neural barriers can help to obtain more information about the pathways and carriers. This paper summarizes investigations on the size distribution of Mn carriers (e.g. proteins, peptides, carbonic acids) in serum before the neural barriers and in cerebrospinal fluid (CSF) behind them as a first characterization step of the Mn carriers being involved in moving Mn across the neural barriers. Further identification of Mn-species in CSF was successfully achieved by CZE–inductively coupled plasma (ICP)–dynamic reaction cell (DRC)–mass spectrometry (MS). Serum samples showed Mn mean concentrations of 1.7±0.8 μg L⁻¹. The size distribution of Mn-carriers showed a main peak in the TF/albumin size fitting to the known physiological ligands. However, also an increasing Mn peak at 700 Da with increasing total Mn concentration was seen. Samples of CSF showed Mn mean concentrations of 2.6 μg L⁻¹=48 nM. In CSF Mn was found to be mostly bound to low-molecular-mass (LMM)-Mn carriers in the range of 640–680 Da. This is similar to the LMM compound in serum and to Mn–citrate complexes suggested to be present in body fluids. Citrate concentration was 573 μM, thus being in huge excess compared to Mn. CSF was further analyzed by CZE–ICP–DRC–MS. Several Mn-species were monitored and mostly identified. The most abundant Mn-species was Mn–citrate at a concentration of around 0.7 μg Mn L⁻¹.     

Measurement of cerium in human breast milk and blood samples

The aim of this study was to evaluate the relationship between cerium content in human breast milk and blood plasma or serum. Blood samples and breast milk at various stages of lactation, from 5 days to 51 weeks post partum, were donated by 42 healthy breast-feeding mothers from Munich, Germany and by 26 lactating Spanish mothers from Madrid at 4 weeks post partum. Inductively coupled plasma mass spectrometry was applied for the determination of cerium in the biological samples. Cerium concentration in the digested milk samples from Munich showed low values and the arithmetic mean values ranged between the quantification limit of 5 ng/L up to 65 ng/L. The median value amounted to 13 ng/L. The cerium concentrations in the Spanish breast milk samples amounted to similar low values. The data were about a factor of eight lower than values found in a former study of samples from an eastern German province. All cerium concentrations in the German plasma samples, except for two, were at the quantification limit of 10 ng/L. Interestingly, the serum samples of the Spanish mothers showed cerium values ranging between 21.6 and 70.3 ng/L; these higher data could be explained by an enhanced intake of cerium by humans in Madrid. This could be caused by increased cerium concentrations in particulate matter due to a higher traffic volume in Madrid compared to Munich.The results obtained in this study contribute to setting reference baseline values of cerium in human breast milk and blood plasma/serum and indicate a varying cerium amount depending on the cerium environmental pollution. Possibly, the cerium content in plasma/serum could be an indicator for environmental cerium, which is not valid for breast milk.     

Blood lead and cadmium levels in a six hospital employee population. PESA study, 2009

IntroductionExposure to lead and cadmium is a public health problem due to the broad exposure to these toxic substances among the general population. The objective of this study is to determine blood lead and cadmium concentrations in a working population drawn from six university hospitals in Madrid, Getafe, Cartagena, Santiago de Compostela, Santander and Palma de Mallorca (Spain) and to identify associated factors.Materials and methods951 individuals participated in the study and were administered the standardized PESA^® questionnaire regarding exposure to lead and cadmium. The blood lead and cadmium concentrations were measured by electrothermal atomization atomic absorption spectrometry with Zeeman background correction in Perkin-Elmer spectrometers, guaranteeing the transferability of the results.ResultsThe median overall blood lead concentration was: 1.6 μg/dL (IQR: 0.9–2.7) and that of cadmium was: 0.21 μg/L (IQR: 0.10–0.50). There were significant differences in lead levels between men (2 μg/dL) and women (1.5 μg/dL), postmenopausal (2.6 μg/dL) and premenopausal women (1.1 μg/dL), and between participants who cooked in earthenware (2.1 μg/dL) and those who did not (1.5 μg/dL). The median of cadmium in women (0.24 μg/L) was higher than in men (0.11 μg/L) and was also higher in subjects who smoked (0.70 μg/L) than in non-smokers (0.13 μg/L).ConclusionsA reduction in blood lead and cadmium levels was observed with respect to previous studies carried out in Spain. Nevertheless, the results suggest there are certain factors which increase risk such as age, gender, menopause, age of housing, cooking in lead-glazed earthenware and exposure to cigarette smoke.     

Characterization of a rapid and reliable method for iodide biomonitoring in serum and urine based on ion chromatography–ICP-mass spectrometry

An appropriate and controlled supply of thyroid hormones is vital for proper body function. In turn, an appropriate synthesis of T3 and T4 in the thyroid gland is dependent on a sufficient and balanced iodide concentration in blood serum. Due to widespread iodine deficiency or some cases of iodine over exposure, iodide biomonitoring in serum is important and it is that biomonitoring approach being closest to the bioavailable I⁻ supply for the thyroid gland. Therefore, this paper describes a biomonitoring method for iodide determination in serum based on ion chromatography–inductively coupled plasma mass spectrometry (IC–ICP-MS). Since in literature only very few data are available on iodide in serum but many in urine the method is also extended to I⁻ monitoring in urine. The method was additionally designed to have short analysis time (8 min) for increased sample throughput, good precision in serial measurement (serum: 4.86%; urine: 1.4%), and day-to-day determination (serum: 5.7%; urine: 2.28%), high accuracy (serum: 105%; urine: 101%) and good recovery (serum: 102%; urine: 99%) even in matrix-rich samples at low I⁻ concentration. Also, investigations were performed to elucidate whether internal standardization during chromatography, sample preparation for protein-matrix removal or matrix-matched calibration are advantageous for analytical performance. Finally, limits of detection (3σ) of 0.12 μg/L or 0.05 μg/L (serum or urine) and limit of quantification (10σ) of 0.39 μg/L or 0.17 μg/L (serum or urine) were achieved.     

Urine as a material for evaluation of exposure to manganese in methcathinone users

Chronic exposure even to low doses of manganese may lead to development of neurological syndrome similar to parkinsonism. The aim of this research is to assess the possibility of manganese poisoning based on the level of metal in the urine of long-term methcathinone users from Poland. Graphite furnace atomic absorption spectroscopy (GFAAS) was used to determine manganese in urine, while the detection of the psychoactive drugs was performed by high-performance liquid chromatography (HPLC). Results of survey on longitudinal patterns of drug use showed that users of traditional illicit drugs now turn to cheaper alternatives, such as methcathinone. Parkinsonian features were observed in almost half of methcathinone users. The subjects had a higher mean level of Mn in their urine (8.68 ± 9.27 μg L⁻¹) than the controls (4.27 ± 1.91 μg L⁻¹). The presence of numerous psychoactive substances (in unchanged forms and their metabolites) was confirmed in all of the samples, with only one exception. The elevated level of manganese in urine (in 29.2% of patients) can be used as a primary marker of recent methcathinone administration, especially in the case of long time intravenous drug users where blood sampling is complicated.     

Toxic and essential elements in children's blood (<6 years) from Kinshasa,DRC (the Democratic Republic of Congo)

In this study we determined the concentration of 9 trace elements (As, Cd, Cu, Hg, Mn, Mo, Pb, Se and Zn) in whole blood of children (n = 100, 64 girls, 36 boys and median age: 36 months) using inductively coupled plasma mass spectrometry (ICP-MS). The proportion of children potentially deficient in essential elements or poisoned by toxic elements was evaluated. The aging effects on the concentration of these elements were also investigated. The median values were 3.17 μg/L (As), 0.15 μg/L (Cd), 1.1 mg/L (Cu), 2.1 μg/L (Hg), 10.4 μg/L (Mn), 17.7 μg/L (Mo), 8.7 μg/dL (Pb), 10.7 μg/L (Se) and 5.0 mg/L (Zn). The concentration of many elements (As, Cd, Hg, Mn, Pb and Zn) showed significant age variations but not sex influence. Regarding levels of the essential elements (Cu, Mn, Mo, Se and Zn), B-Cu, B-Mn, B-Se and B-Zn were in the normal range, whereas exceeded levels were observed for B-Mo. None of these children was deficient in essential elements. Except B-Cd, all toxic elements showed exceeded blood levels. The proportion of children potentially poisoned by toxic elements varies from 10% (n = 10) to 95% (n = 95) and depends on toxic element: 95% for As, 10% for Hg and 35% for Pb. The main health concerns emerging from this study are the high As, Hg and Pb exposures of the Kinshasan children requiring further documentation, corrective actions and the implementation of appropriate regulations.     

Gender difference in blood cadmium concentration in the general population: Can it be explained by iron deficiency?

IntroductionGender differences in blood cadmium concentrations and the effect of iron deficiency on blood cadmium levels were analyzed in a representative sample of Koreans assessed in the Korean National Health and Nutritional Examination Survey (KNHANES) 2008–2011.MethodsA rolling sampling design was used to perform a complex, stratified, multistage probability cluster survey of a representative sample of the non-institutionalized civilian population in South Korea. Serum ferritin was categorized as low (<15.0 μg/L), low normal (15.0–<30.0 μg/L for females and 15.0–<50.0 μg/L for males), and normal (≥30.0 μg/L for females and ≥50.0 μg/L for males), and its association with blood cadmium levels was assessed after adjustment for various demographic and lifestyle factors.ResultsThe geometric mean (GM) of the blood cadmium level was significantly higher in females than in males, and significantly higher in older individuals for both genders. After controlling for covariates, multiple regression analysis with interaction terms showed that blood cadmium was correlated with serum ferritin levels only in pre-menopausal females.DiscussionIron deficiency is associated with blood cadmium levels in a representative sample of pre-menopausal females, as evaluated in KNHANES. Gender differences in blood cadmium concentration may not be due solely to an iron deficiency-associated increase in blood cadmium.     

DNA damage induction and antiproliferative activity of vanadium(V) oxido monoperoxido complex containing two bidentate heteroligands

Several peroxidovanadium(V) complexes have been shown as a potent anticancer agents. The aim of this study was to investigate the interaction of monoperoxidovanadium(V) complex Pr₄N[VO(O₂)(ox)(phen)], (Vphen), [phen = 1,10-phenantroline, ox = oxalate(2?) and Pr₄N = tetra(n-propyl)ammonium(1+)] with DNA. UV–Vis spectrophotometry and the alkaline single-cell gel electrophoresis (SCGE, the comet assay) were used to examine the possibility of the vanadium(V) complex to induce changes in DNA. The interaction of Vphen with calf thymus DNA resulted in absorption hyperchromicity in DNA spectrum and shift of the absorption band of DNA to longer wavelengths for the [complex]/[DNA] concentration ratio equals to 4 and after 60 min of incubation. The rise in DNA absorption (by 34%) and bathochromic shift (Δλ_max = 6 nm) are indicative of the interaction between DNA and the complex molecules. DNA strand breaks in cellular DNA were investigated using the comet assay. The human lymphocytes were exposed to various concentrations of Vphen for 30 min. The results revealed that Vphen contributed to the DNA damage expressed as DNA strand breaks in concentration dependent manner. The used concentrations of Vphen (ranging from 0.1 to 100 μmol/L) caused higher DNA damage in lymphocytes compared to untreated cells (from 1.2 times for 0.1 μmol/L to 1.8 times for 100 μmol/L). Vphen was screened for its potential antitumor activity towards murine leukemia cell line L1210. Vphen exhibited significant antiproliferative activity depending on its concentration and time of exposure. The IC₅₀ values were 0.247 μg/mL (0.45 μmol/L) for 24 h, 0.671 μg/mL (1.21 μmol/L) for 48 h and 0.627 μg/mL (1.13 μmol/L) for 72 h.     

Increased whole blood manganese concentrations observed in children with iron deficiency anaemia

A prospective observational study was carried out at Alder Hey Children's Hospital, Liverpool, England, UK on children aged 1–6 years attending the pathology department for routine blood tests (n = 225). Whole blood manganese concentrations were measured plus the following markers of iron status; haemoglobin, MCV, MCH, RBC count, ferritin, transferrin saturation and soluble transferrin receptors. Multiple regression analysis was performed, with blood manganese as the dependent variable and factors of iron status, age and gender as independent variables. A strong relationship between blood manganese and iron deficiency was demonstrated (adjusted R² = 34.3%, p < 0.001) and the primary contributing factors to this relationship were haematological indices and soluble transferrin receptors. Subjects were categorised according to iron status using serum ferritin, transferrin saturation and haemoglobin indices. Children with iron deficiency anaemia had higher median blood manganese concentrations (16.4 μg/L, range 11.7–42.4, n = 20) than children with iron sufficiency (11 μg/L, range 5.9–20.9, n = 59, p < 0.001). This suggests that children with iron deficiency anaemia may be at risk from manganese toxicity (whole blood manganese >20 μg/L), and that this may lead to neurological problems. Treatment of iron deficiency in children is important both to improve iron status and to reduce the risk of manganese toxicity.     

Bloodletting therapy in hemochromatosis: Does it affect trace element homeostasis?

Hemochromatosis is the most common hereditary disorder in the Nordic population, if left untreated it can result in severe parenchymal iron accumulation. Bloodletting is mainstay treatment. Iron and trace elements partially share cellular uptake and transport mechanisms, and the aim of the present study was to see if bloodletting for hemochromatosis affects trace elements homeostasis. We recruited patients referred for diagnosis and treatment of hemochromatosis, four women and 22 men 23–68 years of age. Thirteen were C282Y homozygote, one was C282Y heterozygote, three were H63D homozygote, seven were compound heterozygote and two had none of the mutations above. Iron and liver function tests were performed; serum levels of trace elements were measured using inductively coupled plasma mass spectrometry. Results before the start of treatment and after normalization of iron parameters were compared. On completion of the bloodlettings the following average serum concentrations increased: Co from 5.6 to 11.5 nmol/L, serum Cu 16.2–17.6 μmol/L, Ni increased from 50.0 to 52.6 nmol/L and Sb from 13.2 to 16.3 nmol/L. Average serum Mn concentration declined from 30.2 to 28.3 nmol/L. All changes were statistically significant (by paired t-test). B, Ba, Cs, Mo, Se, Sr and Zn were not significantly changed. We conclude that bloodlettings in hemochromatosis lead to changes in trace element metabolism, including increased absorption of potentially toxic elements.     

Effects of arsenic (As) exposure on the antioxidant status of gills of the zebrafish Danio rerio (Cyprinidae)

In fishes, arsenic (As) is absorbed via the gills and is capable of causing disturbance to the antioxidant system. The objective of present study was to evaluate antioxidant responses after As exposure in gills of zebrafish (Danio rerio, Cyprinidae). Fish were exposed for 48 h to three concentration of As, including the highest As concentration allowed by current Brazilian legislation (10 μg As/L). A control group was exposed to tap water (pH 8.0; 26 °C; 7.20 mg O₂/L). As exposure resulted in (1) an increase (p < 0.05) of glutathione (GSH) levels after exposure to 10 and 100 μg As/L, (2) an increase of the glutamate cysteine ligase (GCL) activity in the same concentrations (p < 0.05), (3) no significant differences in terms of glutathione reductase, glutathione-S-transferase and catalase activities; (4) a significantly lower (p < 0.05) oxygen consumption after exposure to 100 μg As/L; (4) no differences in terms of oxygen reactive species generation and lipid peroxidation content (p > 0,05). In the gills, only inorganic As was detected. Overall, it can be concluded that As affected the antioxidant responses increasing GCL activity and GSH levels, even at concentration considered safe by Brazilian legislation.     

Selenium status in elderly: Relation to cognitive decline

Studies show that decreased antioxidant system is related to cognitive decline. Thus we aimed to measure selenium (Se) status in Alzheimer's disease (AD) and mild cognitive impairment (MCI) elderly and compared them with a control group (CG). 27 AD, 17 MCI and 28 control elderly were evaluated. Se concentration was determined in plasma and erythrocyte by using hydride generation atomic absorption spectroscopy. Erythrocyte Se concentration in AD group was lower than CG (43.73 ± 23.02 μg/L and 79.15 ± 46.37 μg/L; p = 0.001), but not statistically different from MCI group (63.97 ± 18.26 μg/L; p = 0.156). AD group exhibited the lowest plasma Se level (34.49 ± 19.94 μg/L) when compared to MCI (61.36 ± 16.08 μg/L; p = 0.000) and to CG (50.99 ± 21.06 μg/L; p = 0.010). It is observed that erythrocyte Se decreases as cognition function does. Since erythrocyte reflects longer-term nutritional status, the data point to the importance of the relation between Se exposure and cognitive function. Our findings suggest that the deficiency of Se may contribute to cognitive decline among aging people.     

Anatomical variations in primary teeth microelements with known differences in lead content by micro-Synchrotron Radiation X-Ray Fluorescence (μ-SRXRF) – A preliminary study

Shed teeth have been proposed as trace element biomarkers. This study determined variations in the spatial distribution of Ca, K, Zn, Pb, Mn, Cu, and Sr in four anatomical locations: superficial enamel (SE, 0–10 μm), subsuperficial enamel (SSE, 10–30 μm), primary dentin (PD), and secondary dentin (SD). Five primary incisors were analyzed by micro Synchrotron Radiation X-Ray Fluorescence (μ-SRXRF). Two teeth had low concentrations of lead in the SE (<250 μg/g), while three contained very high lead concentrations in the SE (>2000 μg/g). Teeth were sliced, and five spot measurements (20 μm beam diameter) were accomplished in each location. The data are shown as absolute values and as the ratio between the different elements and Ca. The distribution of K was close to that of Ca. Zn was the third most abundant element, with the highest levels being found in the SE and SD and low levels detected in the PD. Increasing Sr levels were found progressing from the enamel to the dentin, with the highest levels being found in the SD, a distribution that was unique. Pb, Mn, and Cu exhibited a similar trend, with higher signals for these elements detected in the SE. This study provides preliminary data on the heterogeneous distribution of different elements in the tooth, highlighting the importance of the first 10 μm of the SE for determination of some elements, such as Zn, Pb, Mn, and Cu.     

Dissolved reactive manganese as a new index determining the trophic status of limnic waters

Dissolved reactive manganese seems to be one of the parameters which determines the trophic status of limnic waters, as suggested by its strong correlations with total phosphorus, chlorophyll a, and water pH. The determination of the trophic status involved the application of reactive manganese due to its bioavailability, providing information on the actual, not just the potential (as in the case of total phosphorus or total organic carbon), threat of water eutrophication.The calculation of trophic states index (TSI) based on the reactive manganese concentration, as determined by TSI_DRMn = 20.61 ln (DRMn) − 35.03, permits the rational assessment of the trophic status of lakes. Oligotrophic lakes are distinguished by concentrations of DRMn < 25 μg/L, mesotrophic by 25–60 μg/L, eutrophic by 60–150 μg/L, and hypertrophic by >150 μg/L.The trophic status of 25 lakes located in central Europe in north-eastern Poland was determined based on the proposed “manganese index” and verified by commonly applied indices proposed by Carlson, Kratzer and Brezonik, and Dunalska.     

Selenium accumulation in the floral tissues of two Brassicaceae species and its impact on floral traits and plant performance

Selenium (Se) is a metalloid that can occur naturally in soils from the Cretaceous shale deposits of a prehistoric inland sea in the western United States. Agricultural irrigation and runoff solubilizes Se from these shales, causing buildups of toxic levels of selenate (SeO₄²⁻) in water and soil. Our main objective was to investigate the accumulation of Se in two Brassicaceae species chosen for their potential as phytoremediators of Se contaminated soils. We tested the hypothesis that Se will accumulate in the pollen and nectar of two plant species and negatively affect floral traits and plant reproduction. Certain species of Brassicaceae can accumulate high concentrations of Se in their leaf tissues. In this study Se accumulation in plant tissues was investigated under greenhouse conditions. Se accumulator (Brassica juncea) and Se hyperaccumulator (Stanleya pinnata) plants were irrigated in sand culture with 0 μM selenate (control), 8 μM selenate, and 13 μM selenate.Nectar and pollen in S. pinnata contained up to 150 μg Se mL⁻¹ wet weight and 12900 μg Se g⁻¹ dry weight when irrigated with 8 μM selenate. Se levels in nectar (110 μg Se mL⁻¹ wet weight) and pollen (1700 μg Se g⁻¹ dry weight) were not as high in B. juncea. Floral display width, petal area and seed pod length were significantly reduced in the 13 μM selenate Se treatment in B. juncea. S. pinnata floral traits and seeds were unaffected by the Se treatments.This study provides crucial information about where some of the highest concentrations of Se are found in two phytoremediators, and may shed light on the potential risks pollinators may face when foraging upon these accumulating plants. In the field, duration of the plant's exposure, Se soil and water concentrations as well as other environmental factors may also play important roles in determining how much Se is accumulated into the leaf and floral tissues. Our greenhouse study shed light on two species’ ability to accumulate Se, as well as determined the specific plant tissues where Se concentrations are highest.     

International variability in diet and requirements of manganese: Causes and consequences

Manganese (Mn) is an essential trace element that is critical for human health and development. At the turn of the century when diets were based on whole grains, cereals and other traditional foods, Mn intakes (8–9 mg/d) were much greater than that prevalent today (2 mg/d). As societies have developed, diets have shifted as part of a nutrition transition, to those that are high in processed foods, fat, and sugar. These foods are virtually devoid of Mn. Thus, dietary Mn has declined substantially throughout the world, as confirmed by several wide-scale, total diet studies.International variability in dietary Mn is considerable, due to tremendous diversity in food and culture. In countries where fruit and vegetable intake may be limited, i.e. the United Kingdom, populations may ingest much lower levels of Mn (1.4 mg/d) as compared to Asian cultures (4 mg/d) which have an abundance of plant foods in their food supply and cuisine. The bioavailability of Mn must be considered, including chemical form, oxidation state, mineral-mineral interactions, presence of dietary components and traditional food processing techniques (milling, germination, malting, fermentation). Manganese toxicity is a public health problem that results from exposure to a naturally high water source or contaminated environment of the soil and/or drinking water. In contrast, inadequate intake is associated with adverse health effects such as diabetes, metabolic syndrome, poor birth outcomes and possibly, cancer. Future studies are recommended to set dietary standards for this mineral in countries that lack recommendations to help achieve optimal health.     

Saxitoxin monitoring in three species of Florida puffer fish

Beginning in April 2002, three species of Florida puffer fish from around the state of Florida, USA were monitored for the presence of saxitoxin (STX). In total, 873 southern (Sphoeroides nephelus), 171 checkered (S. testudineus), and 53 bandtail (S. spengleri) puffer fish were collected between 2002 and 2006 from eight regions: Jacksonville, the Indian River Lagoon, Tequesta, the Florida Keys, Charlotte Harbor, Tampa Bay, Cedar Key, and Apalachicola. Emphasis was placed on collecting specimens from the Indian River Lagoon (IRL), where recreational harvesting of puffer fish led to 28 cases of saxitoxin puffer fish poisoning (SPFP) between January 2002 and May 2004. Southern puffer fish from the northern IRL routinely contained the highest concentrations of STX, with average levels in the skin of 1787 μg STXequiv./100 g tissue. Elevated concentrations were also found in the muscle (1102 μg STXequiv./100 g), gut contents (539 μg STXequiv./100 g), gonads (654 μg STXequiv./100 g), and liver (214 μg STXequiv./100 g). Lower, yet significant (above the action limit of 80 μg STXequiv./100 g tissue), concentrations of STX were also detected in the skin (599 μg STXequiv./100 g), muscle (233 μg STXequiv./100 g), gut contents (197 μg STXequiv./100 g), and gonads (239 μg STXequiv./100 g) of southern puffer fish from Tequesta in the southern IRL, as well as in the gonads (122 μg STXequiv./100 g) of Jacksonville southern puffer fish and the skin (265 μg STXequiv./100 g) of Tampa Bay southern puffer fish. STX concentrations above the action limit were also found in the skin of bandtail puffer fish from the IRL (620 μg STXequiv./100 g), Tequesta (374 μg STXequiv./100 g), and the Florida Keys (230 μg STXequiv./100 g). Checkered puffer fish collected from the IRL, Tequesta, and the Florida Keys on average were nontoxic, containing STX levels below the action limit in all tissues.     

Serum selenium levels of the very low birth weight premature newborn infants with bronchopulmonary dysplasia

BackgroundThe selenium (Se) is an essential trace element that has a critical role in synthesis and activity of a number of selenoproteins with protective properties against free radical damage. This study was conducted to detect the serum Se concentration in very low birth weight (VLBW) preterm infants and its association with bronchopulmonary dysplasia (BPD).Materials and methodsCord blood Se concentration was determined in 54 neonates with gestation age 30 week or less. Another sample was obtained from these infants at day 28 of birth and serum Se levels were measured by atomic absorption spectrophotometer. All neonates were followed for oxygen dependency at 28 day after birth and 36 week postmenstrual age.ResultsThe mean cord blood Se concentration in studied neonates was 64.78 ± 20.73 μg L^?1. Serum Se concentration was 60.33 ± 26.62 μg L^?1 at age 28-day. No significant correlation was observed for serum Se concentration at birth and at one month after birth (r = ?0.04, p = 0.72). BPD was diagnosed in 25 neonates (46%). The mean serum Se concentration at one month was 57.16 ± 29.68 μg L^?1 in patients with BPD (25 cases) and 63.27 ± 23.6 μg L^?1 in 29 patients without BPD (p = 0.40).ConclusionIn our study, serum Se concentration at 28 day of birth was lower than cord blood levels in preterm neonates, but we have not found significant difference among patients who had BPD or not with respect to serum Se concentrations at this age.