Tissue Mn Research Articles

Final report of the CCQM-K145: toxic and essential elements in bovine liver

Liver plays a major role in metabolism and acts as a source of energy for the body by storing glycogen. With the growing interest and investigation in the biological effects in recent years, it is important and necessary to develop accurate and comparable analytical methods for elements in bio-samples. It has, however, been 10 years since the tissue sample (bovine liver) of CCQM-K49 key comparison. The purpose of CCQM-K145 is to ensure the comparable and traceable measurement results for essential and toxic elements such as P, S, Zn, Mn, Ni, Mo, Sr, Cr, Co, Pb, As and Hg in bovine liver among NMIs and other designated measurement bodies worldwide. The comparison was agreed by IAWG as 6th IAWG Benchmarking Exercise with Zn and Ni as exemplary elements at the meeting in Korea in the early October 2016. The results of CCQM-K145 are expected to cover the measurement capability and support CMCs claiming for inorganic elements in the similar biological tissue materials and food samples.30 NMIs and DIs registered in CCQM-K145. With respect to the methodology, a variety of techniques such as IDMS, ICP-OES, ICP-MS(non-ID), AAS and NAA were adopted by the participants. For Zn, Ni, Sr, Pb and Hg measurements, most participants chose ID-ICP-MS method, which showed the better performance in terms of consistency and reliability of the measurement results. In aspect of the traceability for the measurement results in CCQM-K145, most participants used their own (in house) CRMs or other NMI's CRMs to guarantee trace to SI unit. Most participants used similar matrix CRMs for quality control or method validation.Base on different statistic way to calculate the reference mass fraction values and associated uncertainties for each measurand, removal of the suspected extreme values, and discussion at the IAWG meetings, the median values are proposed as the KCRV for Zn, Ni, Mn, Mo, Cr, Pb and Hg; the arithmetic mean values are proposed as the KCRV for P, S, Sr, Co and As. In general, the performances of the majority of CCQM-K145 participants are very good, illustrating their measurement capabilities for Zn, Ni, P, S, Mn, Mo, Sr, Cr, As, Co, Pb and Hg in a complex biological tissue matrix.Bovine liver contains many kinds of nutrients and microelements, it can be regarded as a typical representative material of biological tissue and food. In CCQM-K145, the analytes involved alkali metals and transition elements, metalloids / semi-metals and non metals with a range of mass fraction from mg/g to μg/kg. CCQM-K145 also tested the ability of NMIs/DIs to determine elements that were easy to be lost and polluted, and interfered significantly. The chemical pretreatment methods of samples used in the comparison is suitable for general food and biological matrix samples. A variety of measurement methods used in the comparison represent the main instrumental technology for elemental analysis. Therefore, for supporting CMC claim, CCQM-K145 is readily applicable to measurement of more elements in a wide range of biological materials (including liquids and solids) and meat products.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Acute and long-term manganese exposure and subsequent accumulation in relation to idiopathic blindness in the American lobster, Homarus americanus

Manganese (Mn) is a hypoxic reactive metal commonly found in marine sediments. Under hypoxic conditions the metal becomes fully reduced to Mn2+ and is biologically available to the benthic community for uptake. Mn is also a potent neurotoxin and it may play a role in the etiology of idiopathic blindness that has been observed in American lobsters. An acute exposure study was designed to expose American lobster, Homarus americanus, to 0, 20, 80, 150, and 300 mg L−1 (ppm) for 96 hs to explore disparities in Mn accumulation among several tissues: optic nerve, brain, hepatopancreas, muscle, hemolymph, gill, and exoskeleton. These concentrations were based on realistic pore-water concentrations (20 mg L−1), high sediment concentrations (80 mg L−1), and unrealistically high concentrations to determine lethality (150 and 300 mg L−1). A positive correlation between Mn accumulation and exposure concentration was observed in all tissues examined. In the internal tissues, manganese concentrations showed a high affinity towards brain, optic nerve, and hemolymph. In the exoskeleton and gills, Mn concentrations were also high, possibly because of internal uptake as well as external adsorption. Concentrations of Mn in tissues from the acute exposure study followed the accumulation pattern: hemolymph > gill > exoskeleton > optic nerve > brain > hepatopancreas = muscle. A long-term exposure study lasting seven weeks was designed to investigate the potential link between high Mn exposure and idiopathic blindness, a condition that affects an estimated 50 % of the adult American lobster population off Southern New England (SNE), USA. A comparison of these exposure studies showed evidence of time-dependent Mn accumulation in brain, muscle, exoskeleton, and gill tissue. Although the relationship between Mn exposure and blindness was not apparent, there was a modest trend in the development of blindness (Chi-square, p = 0.102) in animals exposed to a high concentration (150 mg L−1) of the metal. With no mortalities occurring in the acute study and only one mortality in the long-term study, it is highly unlikely that Mn is acutely toxic to American lobsters at environmentally relevant concentrations. Its potential role in idiopathic blindness remains to be determined.

Spatial variations of trace elements contents in macrophytes within Belarusian lakes

The spatial variation of trace elements contents of heavy metals (Ti, V, Cr, Mn, Ni, Cu, Pb) in higher aquatic plants of Belarusian lakes has been analyzed according to monitoring data. Natural variability limits of metals contents in aquatic plants of lakes within principal rivers basins of Belarus have been determined. The data on trace elements contents in macrophytes of Belarus are comparable with the data obtained in Poland and other neighbouring countries. Aquatic plants in lakes are characterized by selective metals accumulation, which is different for ecological groups of submersed, emergent and macrophytes with floating leaves. Statistically significant differences between river basins in the contents of Mn, Cu and Pb have been established in the submersed macrophytes. For all ecological groups, the highest concentrations of Mn in lakes macrophytes tissues are observed in the basins of the Dniapro, Prypiać, Zachodni Buh, and the lowest – the Biarezina. The lakes of the Zachodni Buh and Dniapro basins are distinguished by lower Pb concentrations in aquatic plants. Significant differences in the content of Mn and Cu in the plant tissues within different trophicity lakes have been established. The lowest concentrations of Mn are observed in mesotrophic lakes with signs of oligotrophy. Group analysis of lakes based on the content of Mn, Cu, Pb in macrophyte tissues and spatial constraints has been performed. Among the allocated groups are the lakes of the Braslav district characterized by elevated content of Mn and Cu; lakes of the Vilija basin, distinguished by the lowest average levels of Cu and Pb; lakes of the northern part of Belarus, notable for increased contents of Cu and Pb.

Physiological stress responses, mineral element uptake and phytoremediation potential of Morus alba L. in cadmium-contaminated soil.

Fast growing woody plants are proposed for potential application for phytoremediation of contaminated soil. In this study, the plant growth, physiological responses, mineral element uptake, and phytoremediation potential of the woody plant Morus alba L. were studied in different levels of Cd-contaminated soil through dynamic sampling (30, 60, 120, and 180d). The results indicated that M. alba L. had strong physiological coordination, tolerance and detoxification capacity in response to Cd in contaminated soil. Compared with the control, the photosynthetic pigment content in M. alba L. leaves was significantly suppressed during initial cultivation (30-60d) and the malonaldehyde (MDA) content and electrolyte leakage (EL) were increased from 30 to 120d of cultivation. Furthermore, the uptake of Cu, Mn, and Zn in plant tissues was imbalanced throughout cultivation (30-180d) under 55mg·kg-1 Cd stress. However, the chlorophyll a, chlorophyll b, carotenoid, soluble protein, and soluble sugar contents and the peroxidase (POD) and ascorbate peroxidase (APX) activities in plant leaves, as well as the uptake of macronutrients (K, Ca, and Mg) in plant stems and leaves were maintained at normal levels. Furthermore, the catalase (CAT) activities in plant leaves and the Ca and Mg contents in plant roots were significantly (p<0.05) enhanced in response to Cd stress after 180d of cultivation. Furthermore, the biomass of M. alba L. was significantly increased with cultivation time in Cd-contaminated soil. Therefore, normal photosynthesis, antioxidant protection, and macronutrient regulation contribute to M. alba L. with high tolerance to Cd. Moreover, the uptake and total extraction amount of Cd in aboveground M. alba L. were significantly (p<0.05) increased with both the plant growth period and soil Cd level, and the maximum amount of Cd reached up to 340.5μg·plant-1. Thus, M. alba L. can be regarded as a potential candidate for phytoremediation in Cd-contaminated sites.

PSA targeted dual-modality manganese oxide–mesoporous silica nanoparticles for prostate cancer imaging

Studies have shown the potential of nanomaterials for the accurate and early detection of cancer. The aim of the present study was to design and evaluate the value of prostate-specific membrane antigen (PSA)-targeted manganese oxide–mesoporous silica nanoparticles (Mn–Msns) for the detection of prostate cancer. Mn–Msns were prepared, and then conjugated with the PSA antibody and Cy7 to create the multimodality PSA-Mn-Msn-Cy7. Their particle size, zeta potential, stability and magnetic resonance imaging (MRI) features of the nanoparticles were characterized. Optical and MR imaging were evaluated in cell and tumor-bearing mouse models. The Mn in tissues was measured by inductively coupled plasma mass spectrometry. The fabricated nanoparticles were stable and showed good T1relaxivity. The targeted nanoparticles accumulated to a great extent in prostate cancer cells in vitro but not in noncancerous cells. In vivo studies further demonstrated a targeted distribution of PSA-Mn-Msn-Cy7 to cancer tissues as shown by high optical and T1 signals. The targeted distribution was also confirmed by determining the Mn content in the cancer tissues. Our data demonstrate that PSA targeted fluorescence and MR dual-functional nanoparticle can visualize prostate cancer and can be used as NIRF/MR contrast agents.

Silicon Compensates Phosphorus Deficit-Induced Growth Inhibition by Improving Photosynthetic Capacity, Antioxidant Potential, and Nutrient Homeostasis in Tomato

Phosphorus (P) deficiency in soils is a major problem for sustainable crop production worldwide. Silicon (Si) is a beneficial element that can promote plant growth, development and responses to stresses. However, the effect of Si on tomato (Solanum lycopersicum L.) growth, photosynthesis and mineral uptake under P deficit conditions and underlying mechanisms remain unclear. Here, we showed that low P (LP) supply inhibited tomato growth as revealed by significantly decreased fresh and dry weights of shoots and impaired root morphological traits. LP-induced growth inhibition was associated with decreased photosynthetic pigment content, net photosynthetic rate (Pn), stomatal conductance, transpiration rate and water use efficiency. However, exogenous Si application alleviated LP-induced decreases in growth and physiological parameters. In particular, Si increased Pn by 65.2%, leading to a significantly increased biomass accumulation. Biochemical quantification and in situ visualization of reactive oxygen species (ROS) showed increased ROS (O2−· and H2O2) accumulation under LP stress, which eventually elevated lipid peroxidation. Interestingly, exogenous Si decreased ROS and malondialdehyde levels by substantially increasing the activity of antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase. In addition, Si increased concentrations of osmoregulatory substances, such as proline, soluble sugar, soluble proteins, free amino acids, and organic acids under LP stress. Analysis of major element concentrations revealed that exogenous Si application under LP stress not only increased Si uptake but also enhanced the concentrations of most essential elements (K, Na, Ca, Mg, Fe, and Mn) in different tissues (roots, leaves, and stems). These results reveal that Si mitigates LP stress by improving photosynthetic capacity, antioxidant potential, and nutrient homeostasis and that it can be used for agronomic management of vegetable crops in P-deficient soils.

The concentration of selected elements in the placenta according to selected sociodemographic factors and their effect on birth mass and birth length of newborns

Background and aimsThe placenta is a remarkable organ which provides critical transport functions between the maternal and fetal circulations during pregnancy. The demand for mineral components increases during the gestational period, therefore, an appropriate intake of minerals, such as calcium, phosphorus, potassium, magnesium, iron, zinc, copper, and manganese, determines the correct growth and development of a fetus. The aim of the study was to assess the concentration of selected elements in the placenta, and to assess the impact of their concentrations on the birth weight and birth length of newborns. The second aim of the study was to assess the influence of selected sociodemographic factors on the concentration of elements in the placenta. ResultsThe study demonstrated that the age of mothers affected the concentration of Ca and Mn in the placenta, and their habit of tobacco smoking during the gestational period was associated with higher concentrations of Ca, P, K, Mg, Fe, Cu, and Cd in the placental tissue. The results also showed that concentrations of K, Fe, Zn, and Mn in the placental tissue affected birth length. Furthermore, the association was demonstrated between a higher Cd concentration in the placenta (≥ 0.0503 μg/g) and the birth anthropometric parameters of neonates. ConclusionsSmoking during pregnancy and environment pollution are the factors that affects the concentration of elements in the placenta and contributes to their high accumulation in the placenta. Smoking during pregnancy causes an increased concentration of cadmium in the placenta which has negative health effects for the newborn. Women living in a big city or village had a higher concentration of cadmium in their placentas compared to women living in smaller cities. The significant influence of some elements (K, Fe, Zn, Cu and Cd) on the newborn’s birth parameters was also demonstrated. The results of our research indicate the importance of the mother’s lifestyle in providing the placenta with elements, which affects the growth of the fetus.•The placenta is an organ that is responsible for the proper course of pregnancy and fetal development.•The demand for mineral components increases during the gestational period, therefore, an appropriate intake of minerals determines the correct growth and development of a fetus•Increased exposure to arsenic, cadmium and lead during the gestational period can induce miscarriage, premature delivery, risk of fetal death, inhibition of intrauterine growth and development of the fetus, and low birth parameters.

Patella caerulea (Mollusca, Gastropoda) as Bio-Indicator for Certain Pollutants at El-Mex Bay, Alexandria, Egypt

The dominant molluscan speciesPatella caerulea was selected as a trace metals bio indicator. During winter and summer 2016, its specimens were scraped from El-Mex Bay. Concentrations of heavy metals in the water, sediments andPatella caerulea (shells and soft tissues) were determined. Cadmium (Cd), lead (Pb), copper (Cu), iron (Fe), nickel (Ni), manganese (Mn) and zinc (Zn) concentrations (conc.) during summer were higher than winter except for shells which had Cd conc. in summer lower than winter, water showed Cu conc. in winter more than summer, Fe appeared higher conc. in water and Patellacaerulea during winter more than summer, Mn had higher conc. in water and sediments than summer, Ni had higher conc. in water and soft tissues during winter than summer and Zn in water during summer is lower than winter. The bioaccumulation factors (BAFs) ofCd, Pb, Cu, Fe inPatellacaerulea shells were more than soft tissues, also they were more in winter than summer except that of Cu in winter was lower than summer, BAF of Fe in soft tissues was higher than shells also that of Mn and Zn in Patellacaerulea during winter were lower than summer, also BAFs of Mn in soft tissues and shells was nearly similar.The highest metal pollution index (MPI) for the studied species appeared in shells (105.95) followed by that of soft tissues during summer and winter (80.54 and 74.64, respectively). While MPI in shells during winter (46.13) came to the last.

Copper, Nickel and Manganese Residues in Tissues and Organs of Rabbits Dosed with Edible Clay

The study examined the kinetics of Copper (Cu), Nickel (Ni) and Manganese (Mn) in tissues and organs of rabbits treated with edible clay from Enyigba, Ebonyi state Nigeria. Clay samples were obtained from Enyigba mine. Fifty four of the sampled rabbits were grouped into 3: group 1 and group 2 were administered with 2000 mg/kg and 4000 mg/kg of edible clay respectively while group 3 served as control. Concentrations of these metals were detected in the brain, heart, kidney, liver, lungs, skeletal muscle and blood of each of the rabbits using atomic absorption spectroscopy (AAS). One - way ANOVA was used in analyzing the concentrations with significant results (p < 0.05) recorded. The study results showed that while Cu concentrations were predominant in the liver (15.33±1.18 µg/g), kidney (8.25±1.18 µg/g) and heart (9.43±2.36 µg/g) of 2000 mg/kg treated rabbits on day 1 post-treatment, Ni concentrations were the highest among the three elements especially in the blood (221.59±17.05 µg/g) and skeletal muscle (153.41±19.68 µg/g) of 2000 mg/kg treated rabbits on day 1 post-treatment. Concentrations of Mn were mostly detected in the liver (13.99±4.85 µg/g) of 2000 mg/kg treated rabbits on day 1 post-treatment. Most of the concentration values increased in 4000 mg/kg treated rabbits on day 1 post-treatment. Elimination constants as well as half-life eliminations of the metals studied showed that absorbed elements were still present in most organs and tissues of treated rabbits. The study recommends research for possible microbial toxins that may be found in the edible clay studied.

Diferentes doses de calcário aumentam a absorção de nutrientes pelo pinhão-manso

Este trabalho teve por objetivo avaliar se diferentes doses de calcário, aplicadas em subsuperfície, influenciam a absorção de nutrientes em plantas de pinhão-manso (Jatropha curcas L.) em desenvolvimento inicial. O experimento foi realizado em vasos e sob condição de casa de vegetação, em que as plantas de pinhão-manso foram cultivadas em vasos de PVC, divididos em camada superficial (0-20 cm) e camada subsuperficial (20-60 cm). A camada superficial recebeu solo corrigido (11,1 t ha-1 de CaCO3 e MgCO3) e adubação com NPK. Na camada subsuperficial foi adicionado ao solo as doses de 0; 3,7; 5,6; 7,4; 11,1 e 14,9 t ha-1 de CaCO3 e MgCO3 na relação molar 4:1. Após 120 dias da emergência das plantas, avaliaram-se os teores e conteúdos de Al, P, K, Ca, Mg, Zn, Mn, Fe e Cu nas folhas, no caule e nas raízes. Em plantas de pinhão-manso, os teores de Al são maiores nos tecidos radiculares, seguido das folhas e do caule. Os teores e os conteúdos de P, K, Ca, Mg, Zn e Mn no tecido vegetal são influenciados pelo aumento das doses de calcário no solo. Os teores de Fe e Cu nos tecidos vegetais de pinhão-manso sofrem pouca influência das doses crescentes de calcário em subsuperfície.

Heavy metal distribution and uptake by maize in a mudflat soil amended by vermicompost derived from sewage sludge

Sewage sludge has been regarded as an economic and efficient soil amendment for mudflat soil amendment despite of the concern of heavy metal contamination. Converting sewage sludge into vermicompost by earthworms may be effective to minimize the risk of heavy metal contamination caused by direct application of sewage sludge in mudflat soil. The objective of this study was to assess the feasibility of vermicompost amendment (VA), and its influence on heavy metal contamination compared with sewage sludge amendment (SSA) in mudflat soil. The results showed that VA improved the physicochemical properties of mudflat soil by decreasing soil bulk density, salinity, and pH, increasing soil organic carbon, nitrogen, and phosphorus contents in the soil. Consequently, the maize biomass and yield were significantly elevated by VA. For heavy metals, VA increased total Cd, Cu, Ni, Pb, and Zn concentrations in mudflat soil, and the maximum increments occurred at 250 t ha-1. Available Cd, Cu, Mn, Ni, and Zn concentrations significantly increased with increasing VA rates. VA increased the accumulation of Cd, Cu, Mn, Ni, Pb, and Zn in maize tissues, especially in root of maize. Compared with SSA under the condition of maintaining equal carbon input, VA allowed heavy metals to accumulate in a more stable binding form in the top 20-cm layer of mudflat soil. Thus, the risk of runoff and leaching of heavy metals and their bioavailability to plants reduced in mudflat soil. As a result, VA decreased the accumulation of heavy metals in maize plant compared with SSA in mudflat soil. In summary, vermicompost can be an effective and safe substitute for sewage sludge for mudflat amendment.

Manganese levels and hepatocellular carcinoma: A systematic review and meta-analysis based on Asian cohort.

Several studies have investigated the relationship between Manganese (Mn) levels and hepatocellular carcinoma (HCC), but the results were inconsistent. Thus, we conducted a systematic review and meta-analysis to evaluate the association between Mn levels and HCC. Nine studies focusing on hair Mn levels, 6 studies on serum Mn levels and 6 studies on tissue Mn levels were identified in a systematic search of PubMed, CNKI, Wanfang and SinoMed databases. Standard mean differences (SMD) with the corresponding 95% confidence intervals (CI) were pooled to compare the Mn levels between HCC and controls. In serum, the Mn levels in HCC were significantly lower than in healthy controls (SMD (95% CI): −0.941 (−1.559, −0.323)). In hair, the Mn levels in HCC were slightly lower than in healthy controls, but not significant (SMD (95% CI): −0.168 (−0.766, 0.430)). In tissue, the Mn levels in tumors were significantly lower than in adjacent normal tissues (SMD (95% CI): −4.867 (−7.143, −2.592)). Subgroup analysis showed consistent results. In conclusion, this meta-analysis suggested an inverse association between Mn levels and HCC.

Effect of levels and sources of dietary manganese on growth and mineral composition of post-smolt Atlantic salmon fed low fish meal, plant-based ingredient diets

The impact of dietary manganese (Mn) levels and sources on the growth and mineral composition of post-smolt Atlantic salmon (Salmo salar) fed practical diets was studied. Seven experimental diets were prepared with graded supplementation level of Mn; basal diet had a Mn concentration of 15 mg kg−1, four diets with 5, 15, 35 and 65 mg kg−1 supplementation of Mn as MnSO4 and two diets with at 5 and 15 mg kg−1 supplementation of Mn as Mn-glycine (Mn-gly). Atlantic salmon (initial weight, 307 ± 25 g) were distributed to 21 tanks (35 fish/tank). These fish were randomly fed with one of the experimental diets, in triplicate groups to apparent satiation for 8 weeks. At week 4 and 8, samples of whole body, plasma, bile, liver and vertebrae were collected, and their mineral concentration determined. At week 8, feaces were collected by stripping for measuring apparent availability coefficient (AAC). Neither the Mn inclusion level, nor the source had a significant impact on growth and other performance indicators. Plasma and bile Mn concentrations were significantly affected by dietary treatments at both sampling points, at week 4 and 8; whereas, whole body, liver and vertebrae responded significantly only at the end of 8 weeks. Dietary Mn level needed to meet the requirement of post-smolt Atlantic salmon was estimated by non-linear regression models using saturation of whole body or tissue Mn status as response criteria. The estimates based on Mn concentration in whole body, vertebrae, plasma and apparent availability were 29.5 ± 5.3, 26.2 ± 2.7, 26.3 ± 4.9 and 34 ± 3.4 mg Mn kg−1 diet, respectively. Analysis of relative bioavailability index showed that low inclusion of Mn-gly (5 mg kg−1 supplementation) was 2.6 to 4.5-fold more efficient than MnSO4 to attain whole body or tissue Mn saturation levels. On the contrary, high inclusion of Mn-gly (15 mg kg−1 supplementation) reduced the AAC of Mn, zinc (Zn) and copper (Cu), along with lower Mn and Zn status in tissues. The mean estimate of dietary Mn required to maintain tissue Mn saturation ranged between 26 and 34 mg Mn kg−1 diet; the corresponding Mn supplementation (as MnSO4) ranged from 14 to 22 mg Mn kg−1 diet. The supplementation level can be reduced to 4.9 to 5.7 mg Mn kg−1 diet by using Mn-gly as Mn source without compromising growth or Mn status of Atlantic salmon. High inclusion levels of Mn-gly (15 mg kg−1 diet) was found to be not beneficial.

Trace Elements in Surface Soils and Megascolecidae Earthworms in Urban Forests Within Four Land-Uses Around Poughkeepsie, New York, USA.

Amynthas agrestis and Metaphire hilgendorfi are being distributed across North America with unknown ecosystem impacts. Forest soils in urban areas sequester trace elements and earthworms may be bioaccumulating them. This study examined Cd, Cr, Co, Cu, Mn, Ni, Pb, V, and Zn in soils and earthworm tissues at 28 urban forest sites in and surrounding Poughkeepsie, NY, USA. Megascolecidae were present at 22 sites with means of 12 to 27 individuals m-2 and 4 to 12dryweightgm-2. Urban forest soils within commercial uses had Mn, Pb, and Zn concentrations higher than within residential and agricultural uses. Earthworm trace element concentrations were poorly predicted by their respective soil concentrations, except for Pb. Urban forests in commercial uses and land-preserves, earthworm Cd and Pb concentrations were at or above concentrations known to negatively impact small mammal and bird health ( > 10mgkg-1) with Co and V approaching toxic concentrations.

Trace metal biomarker based Cancer diagnostics in body tissue by energy dispersive X-ray fluorescence and scattering spectrometry

Direct diagnosis and characterization of cancer in tissue via trace biometals analyzed by energy dispersive X-ray fluorescence (EDXRF) spectrometry is challenging, as it requires sensitive detection and accurate quantitative analysis of the appropriate cancer biomarkers. The EDXRF spectrometry technique is not directly applicable due to the complexity of the tissue biopsy samples that are of limited size and irregular geometry, enhanced scatter from the sample dark matrix and extreme matrix effects as well as spectral overlaps and prominent Bremsstrahlung that masks the subtle biomarker analyte peaks. We report on the direct determination of biometals namely Cu, Mn, Fe, Zn; Mg, Co and Na and associated speciation (for Cu, Mn, Fe) in soft body tissue in the context of disease diagnostics utilizing a robust chemometrics enabled energy dispersive X-ray fluorescence and scattering (EDXRFS) spectrometric method. The EDXRFS method exploits, in addition to multiple fluorescence spectral signatures, scatter profiles associated with the trace metals and dark matrix to determine through hybridized multivariate chemometrics calibration models, the biometals in thin (10 μm) tissue sections. Wavelet transform (WT), principal component analysis (PCA) and independent component analysis (ICA) were used for spectral preprocessing towards model optimization using con-jointly artificial neural network (ANN) and partial least squares (PLS) based on paraffin wax ‘standards’ spiked with the cancer biomarker trace metals. Results obtained from applying oyster tissue standard validated models (to ≤6% accuracy) to dog tissues (used here as human body tissue analogues) show that both prostate and mammary malignant tissues have significantly high concentration of Zn i.e. 301 ± 4 μg/g and 301 ± 4 μg/g respectively when compared to benign tissues i.e. 160 ± 3 μg/g and 171 ± 10 μg/g. The same is the case for Fe and Cu. The concentrations of Fe, Zn, Cu and Mg in malignant (mammary) as compared to benign tissues occur in the ratios 3:1, 2:1, 3:1 and 2:1. On the other hand, for prostate malignant compared to benign tumor the corresponding ratios are 5:2, 2:1, 2:1 and 2:1 respectively. Prostate cancer was found to be characterized by strong positive correlation between Cu and Mg (0.999) and Mn and Fe (0.999) while mammary cancer is characterized by strong negative correlations between Cu and Mg (−0.994), Mn and Fe (−0.974). ICA and PCA were further used to successfully discriminate the dog tissue to 97% accuracy as either cancerous or non-cancerous based on validated pattern recognition PCA-ICA models for the determination of speciation of Cu, Fe and Mn in soft body tissue. For both mammary and prostate cancer malignancy was characterized by higher speciation of Cu, Fe and Mn (i.e. Cu2+, Fe3+, and Mn7+) compared to the benign. The results of this study demonstrate that robust chemometrics enabled EDXRFS spectrometry not only determine directly and rapidly but also accurately in a diagnostics manner cancer biomarker trace metals in soft body tissue. The technique has an additional advantage in that it has inbuilt multivariate capability to model the determined levels, their ratios and correlations as well as alterations in the speciation of the biometals to detect and characterize cancer (according to severity) as well discriminate among different types of cancer in the same tissue in a simple methodology that has potential for clinical applications.

Effect of manganese preconditioning and replacing inorganic manganese with organic manganese on performance of male broiler chicks

ABSTRACTThe effects of manganese (Mn) preconditioning, 96 h post-hatch followed by the replacement of inorganic Mn with different levels of organic Mn (5 to 21 D), on growth, tissue excreta Mn content, gene expression, and enzyme activity were evaluated. A total of 420 day-old male Cobb 500 broilers were divided into 2 groups. One group was fed a corn–soybean meal basal diet containing 17 mg of Mn/kg (preconditioning diet, MnPD); the second group was fed the non-preconditioning diet (NPCD), which was the MnPD supplemented with 60 mg of Mn/kg from manganese sulfate (MnSO4). On day 5, each group was divided into 5 subgroups and were randomly assigned to dietary treatments consisting of MnPD alone or MnPD supplemented with 12 or 60 mg Mn/kg Mn as MnSO4 or Mn proteinate (6 replicate cages of 6 birds). Broiler chicks that were fed the MnPD had lower (P ≤ 0.05) body weight gain (BWG) and G:F ratio when compared to those that were fed the NPCD for 4 D. Birds that were fed MnPD (1 to 4 D) and switched to MnPD supplemented with 60 mg/kg Mn (5 to 21 D) had lower (P ≤ 0.05) BWG compared to those that were fed NPCD (1 to 4 D) and switched to MnPD supplemented with 60 mg/kg Mn for 21 D. Excreta, tibia ash, liver, and heart Mn levels were increased (P ≤ 0.05) by supplemental Mn. The expression of jejunum divalent metal transporter-1 mRNA levels, as well as activities of plasma total super oxide dismutase and liver alanine transaminase, was not affected by MnPD or Mn source and levels. These results confirmed that feeding marginally deficient Mn diets to broiler chicks post-hatch does affect growth rate and tissue Mn concentration.

Updating physiologically based pharmacokinetic models for manganese by incorporating rapid association/dissociation processes in tissues

Previously, we developed a series of physiologically based pharmacokinetic (PBPK) models for manganese (Mn) in which saturable tissue binding and dose-dependent increases in biliary excretion captured key aspects of Mn homeostasis biology. These models reproduced the non-linear behavior of Mn kinetics in different tissues, accounting for dose-dependent changes in Mn kinetics. The original model construct had relatively slow association and dissociation rate constants for Mn binding in tissues. In this updated model, both rates of entry into tissue and the interaction of Mn with binding sites are rapid, and the step limiting Mn accumulation is the saturation of tissue binding sites. This binding reflects general cellular requirements for Mn with high affinity but rapid exchange between bound and free forms, which we captured using a dissociation constant (KD) of ~ 0.5 μM across tissues while maintaining different maximum binding capacities in each tissue. Variability in the binding capacities accounted for different background levels of Mn in particular tissues. This alternative structure successfully described Mn kinetics in tissues in adult rats exposed to Mn either in their diet or by inhalation, indicating that both the original and the present models capture the dose-dependent and tissue-specific kinetic behavior of Mn in adult rats. Although the published models that emphasize the role of smaller tissue binding rate constants in non-linear behaviors capture all relevant dose-dependent kinetic behaviors of this metal, increasing biological relevance of the model structure and parameters should provide greater confidence in applying the Mn PBPK models to risk assessment.

Interspecies comparison of three moss species (Hylocomium splendens, Pleurozium schreberi, and Isothecium stoloniferum) as biomonitors of trace element deposition.

Biomonitoring with mosses is a common method widely used to assess the spatial and temporal trends of atmospheric deposition in Europe since its introduction in the 1970s. Based on previous investigations, certain moss species provide the most accurate reflection of atmospheric deposition. However, sampling of just one species across large areas can pose a challenge, therefore the ability to use multiple moss species interchangeably is integral to an effective moss biomonitoring survey. In this study, biomonitoring abilities of two common species (Hylocomium splendens [Hs] and Pleurozium schreberi [Ps]) were compared to a potential new biomonitoring species endemic to North America (Isothecium stoloniferum [Is]). Thirteen metal concentrations were analyzed (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, and Pb) in moss tissue from 20 sites with co-located species (Ps/Hs, Is/Hs) Five metals (Al, V, Fe, Ni, and Pb) showed significant and strong correlations (Spearman correlation, r ≥ 0.7 α = 0.05) for all three species, reflecting the established deposition gradient in the region. Furthermore, there was no significant difference in observations (and moderate correlation) for Cr, which suggests that all species exhibited similar uptake abilities for these six metals (Al, V, Cr, Fe, Ni, and Pb). Four metals (Co, As, Se, and Cd) exhibited concentrations below detection at a number of sites, which may have influenced the assessment of interspecies relationships. It is recommended that interspecies calibration be carried out under all surveys that employ multiple moss species.

Bioaccumulation of some trace elements in tropical mangrove plants and snails (Can Gio, Vietnam)

Mangrove sediments can store high amount of pollutants that can be more or less bioavailable depending on environmental conditions. When in available forms, these elements can be subject to an uptake by mangrove biota, and can thus become a problem for human health. The main objective of this study was to assess the distribution of some trace elements (Fe, Mn, Co, Ni, Cr, As, and Cu) in tissues of different plants and snails in a tropical mangrove (Can Gio mangrove Biosphere Reserve) developing downstream a megacity (Ho Chi Minh City, Vietnam). In addition, we were interested in the relationships between mangrove habitats, sediment quality and bioaccumulation in the different tissues studied. Roots and leaves of main mangrove trees (Avicennia alba and Rhizophora apiculata) were collected, as well as different snail species: Chicoreus capucinus, Littoraria melanostoma, Cerithidea obtusa, Nerita articulata. Trace elements concentrations in the different tissues were determined by ICP-MS after digestion with concentrated HNO3 and H2O2. Concentrations differed between stands and tissues, showing the influence of sediment geochemistry, species specific requirements, and eventually adaptation abilities. Regarding plants tissues, the formation of iron plaque on roots may play a key role in preventing Fe and As translocation to the aerial parts of the mangrove trees. Mn presented higher concentrations in the leaves than in the roots, possibly because of physiological requirements. Non-essential elements (Ni, Cr and Co) showed low bioconcentration factors (BCF) in both roots and leaves, probably resulting from their low bioavailability in sediments. Regarding snails, essential elements (Fe, Mn, and Cu) were the dominant ones in their tissues. Most of snails were “macroconcentrators” for Cu, with BCF values reaching up to 42.8 for Cerithidea obtusa. We suggest that high quantity of As in all snails may result from its high bioavailability and from their ability to metabolize As.

The effects of EDTA on plant growth and manganese (Mn) accumulation in Polygonum pubescens Blume cultured in unexplored soil, mining soil and tailing soil from the Pingle Mn mine, China

The effects of water-extractable Mn concentration, bioaccumulation factor (BAF), translocation factor (TF), and Mn uptake by Polygonum pubescens Blume cultured in the unexplored soil, mining soil and tailing soil from the Pingle Mn mine in China were quantified in a pot experiment to determine the effects of EDTA exposure on the success of phytoremediation. The results showed that EDTA significantly (P < 0.05) increased the water-extractable Mn concentration, and soils with different amounts of artificial disturbances had different responses to EDTA exposure. Low and medium EDTA concentrations might have positive effect on plant growth of P. pubescens cultured in the unexplored soil, as indicated by comparable increases in biomass, plant height and photosynthetic pigment content, but opposite results were found with high EDTA concentrations exposure. EDTA exposure had a negative effect on the growth of P. pubescens cultured in the mining soil and tailing soil. In general, the concentration of Mn in different tissues significantly (P < 0.05) increased as the EDTA concentration increased in each soil. The efficacy of Mn remediation by P. pubescens was enhanced in all three soils, with all EDTA treatments.