In this study, four mononuclear M(II)-pyridine-2,5-dicarboxylate (M=Co(II), Ni(II), Cu(II) and Zn(II) complexes with pyridine-2,5-dicarboxylic acid or isocinchomeronic acid, 1,10-phenanthroline (phen), [Co(Hpydc)2(phen)]·H2O (1), [Ni(pydc)(phen)2]·6.5H2O (2) [Cu(pydc)(phen)(H2O)2] (3) and [Zn(pydc)(phen)(H2O)2]·H2O (4) have been synthesized. Elemental, thermal and mass analyses, molar conductance, magnetic susceptibilities, IR and UV/vis spectroscopic studies have been performed to characterize the complexes. Subsequently, these ligands and complexes were tested for antimicrobial activity by disc diffusion method on Gram positive, negative bacteria and yeast. In addition, cytotoxic activity tests were performed on rat glioma (C6) cells by MTT viability assay for 24 and 48h. Antimicrobial activity results demonstrated that when compared to the standard antibiotics, phen displayed the most effective antimicrobial effect. The effect of synthesized complexes was close to phen or less. Cytotoxic activity results showed that IC50 value of phen was determined as 31μM for 48h. (1) and (2) compared to the alone ligand had less toxic activity. IC50 values of (3) for 24 and 48h treatments were 2.5 and 0.6μM, respectively. IC50 value of (4) for 48h was 15μM. In conclusion, phen, (3) and (4) may be useful as antibacterial and antiproliferative agents in the future.

A highly sensitive and selective technique for the speciation of platinum by cloud point extraction prior to determination by graphite furnace atomic absorption spectrometry (GFAAS) was described. The separation of Pt(II) from Pt(IV) was performed in the presence of 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) as chelating agent and Triton X-114 as a non-ionic surfactant. The extraction of Pt(II)-HCPTS complex needs temperature higher than the cloud point temperature of Triton X-114 and pH=7, while Pt(IV) remains in the aqueous phase. The Pt(II) in the surfactant phase was analyzed by GFAAS, and the concentration of Pt(IV) was calculated by subtraction of Pt(II) from total platinum which was directly determined by GFAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. An enrichment factor of 42 was obtained for the preconcentration of Pt(II) with 50mL solution. Under the optimum experimental conditions, the calibration curve was linear up to 30μgL(-1) with detection limit of 0.08μgL(-1) and the relative standard deviation was 1.8%. No considerable interference was observed due to the presence of coexisting anions and cations. The accuracy of the results was verified by analyzing different spiked samples (tap water, blood plasma and urine). The proposed method was applied to the speciation analysis of Pt in blood plasma and urine with satisfactory results.

Oral cancer is a major cause of cancer morbidity and mortality worldwide and is prevalent in most areas where tobacco related practices are observed. Essential elements play a role in many biochemical reactions as a micro-source and there is growing evidence that their concentrations are altered on the onset and progress of malignant disease. In this study the levels of copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo) in serum of patients with oral sub mucous fibrosis (OSMF) (n=30) and oral squamous cell carcinoma (OSCC) (n=30); were determined and the alterations of these critical parameters were analyzed in comparison with controls (n=30) to identify predictors amongst these parameters for disease occurrence and progression. The serum Cu and Zn were established using Flame Atomic Absorption Spectrometry. Serum estimation of Se and Mo was done by graphite furnace atomic absorption spectrometry (GFAAS). Data analysis revealed a marked, progressive and significant increase in Cu levels in precancer (OSMF) and cancer (OSCC) groups as compared to the normal group. The level of Zn in serum was slightly elevated in OSMF and OSCC though not statistically significant. Cu/Zn ratio was slightly but not significantly elevated. Serum levels of Se and Mo were significantly decreased in the precancer and cancer groups as compared to the normals.

PROJECT: Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent, painful oral aphthae, and oxidative stress presumably contributes to its pathogenesis. The aim of this study is to scrutinize the relationship between oxidative stress and serum trace elements (copper, Cu; zinc, Zn; selenium, Se), and to evaluate the ratios of Cu/Zn and Cu/Se in this disorder.

PROCEDURE:

Patients with RAS (n=33) and age- and sex-matched healthy control subjects (n=30) were enrolled in this study. Malondialdehyde (MDA) concentrations in plasma and the activities of superoxide dismutase (SOD1; CuZnSOD), glutathione peroxidase (GPx) and catalase (CAT) in erythrocyte were determined as spectrophotometric. Also, the levels of Se, Zn and Cu in serum were determined on flame and furnace atomic absorption spectrophotometer using Zeeman background correction.

RESULTS AND CONCLUSIONS:

Oxidative stress was confirmed by the significant elevation in plasma MDA, and by the significant decrease in CAT, SOD1, and GPx (p<0.05). When compared to controls, Zn and Se levels were significantly lower in patients, whereas Cu levels was higher in RAS patients than those in controls (p<0.05). In addition, the correlation results of this study were firstly shown that there were significant and positive correlations between Se-CAT, Se-GPx, and Cu-MDA parameters, but negative correlations between Se-Cu, Se-MDA, Cu-CAT, Cu-SOD1 and Cu-GPx parameters in RAS patients. Furthermore, the ratios of Cu/Zn and Cu/Se were significantly higher in the patients than the control subjects (p<0.05). Our results indicated that lipid peroxidation associated with the imbalance of the trace elements seems to play a crucial role in the pathogenesis of RAS. Furthermore, the serum Cu/Zn and Cu/Se ratios may be used as biochemical markers in these patients.

Manganese (Mn) is an essential trace element required for normal growth, development, and cellular homeostasis, but excess Mn is toxic to the central nervous system. The present pilot study examined whether the level of Mn in the placenta was associated with the risk of fetal neural tube defects (NTDs). A case-control study was conducted. Cases were 80 fetuses or newborns with NTDs, and controls were 50 healthy, nonmalformed newborns. Placental Mn, zinc, copper, iron, and selenium were determined with inductively coupled plasma-mass spectrometry. The median Mn concentration was significantly higher in case placentas than in controls: cases, 131.60ng/g (95% confidence interval [CI], 99.25-166.76); controls, 101.54ng/g (95% CI, 80.14-119.79). Mn concentrations above the median were associated with a 4-fold (95% CI, 1.23-14.79) increased risk for any NTDs and a 7-fold (95% CI, 1.52-39.64) increased risk for spina bifida after other confounding factors were controlled. Elevated Mn levels were associated with an increased risk of anencephaly, although the adjusted odds ratio did not reach statistical significance. The association between higher Mn concentrations and risk of NTDs showed a clear dose-response relationship. Risk of NTDs increased to 1.51 (95% CI, 0.65-3.52) and 5.03 (95% CI, 1.89-13.33) for those whose placental Mn level was in the second and third tertiles, respectively, compared with the lowest tertile. Elevated placental concentrations of Mn may be associated with increased risks of NTDs in this population.

A comprehensive review of the analytical literature revealed substantial under-representation of trace element concentrations in fish blood, particularly for marine species. We describe a simple dilution procedure to measure Li, Mg, K, Ca, Mn, Cu, Zn, Se, Rb, Sr, Ba and Pb concentrations in low volumes of blood plasma of adult plaice (Pleuronectes platessa) using high resolution-inductively coupled plasma-mass spectrometry (HR-ICP-MS). Captive male and female plaice (n=18) were serially sampled for one year and samples collected outside of the spawning season (n=157) used to estimate reference ranges for this species. Method accuracy was deemed satisfactory, based on its application to the analysis of a certified reference material. Precision was generally <3%, with the most conservative measure of precision being ≤10% for all elements except Pb (~20%). This is the first study to analyse fish blood plasma by ICP-MS and includes some of the first reference ranges for trace element concentrations in fish blood.

The impact of selenium (Se) in carcinogenesis is still debatable due to inconsistent results of observational studies, recent suspicion of diabetic side effects and e.g. dual roles of glutathione peroxidases (GPx). Previously, our group introduced long-term studies on lung carcinogenesis using the jaagtsiekte sheep retrovirus (JSRV) induced ovine pulmonary adenocarcinoma (OPA) as an innovative animal model. The present report describes the results of sufficient (0.2mg Se/kg dry weight (dw)) vs. marginal (<0.05mg Se/kg dw) nutritional Se supply on cancer progression over a two-year period in 16 animals. Computed tomography (CT) evaluation of lung cancer progression, final pathological examination, evidence of pro-viral JSRV-DNA in lung, lymph nodes and broncho-alveolar lavage cells as well as biochemical analysis of Se, GPx1 and thioredoxin reductase (TrxR) activity in lung tissue were recorded. Additionally, immunohistochemical determination of GPx1 expression in unaffected and neoplastic lung cells was implemented. The feeding regime caused significant differences in Se concentration and GPx1 activity in lung tissue between groups, whereas TrxR activity remained unaffected. JSRV was evident in broncho-alveolar lavage cells, lung tissue and lung lymph nodes. Quarterly executed CT could not demonstrate differences in lung cancer proliferation intensity. Necropsy and histopathology substantiated CT findings. Immunohistochemical analysis of GPx1 in lung tissue suggested a coherency of GPx1 immunolabelling intensity in dependence of tumour size. It was concluded that the model proved to be suitable for long-term studies of lung cancer proliferation including the impact of modifiable nutritional factors. Proliferation of OPA was unaffected by marginal vs. sufficient nutritional Se supply.

This study was performed to characterise key data of long-term ovine Se metabolism and to work out the best biomarker of Se status. An upgrade from marginal (<0.05mg Se/kg diet, 'Se-') to sufficient (0.2mg Se/kg diet, 'Se+') nutritional Se supply using sodium selenite was monitered biweekly by analysing Se concentration, glutathione peroxidase (Gpx) activity and routine biochemistry in blood/serum over 2 years. Se, Cu, Zn, cytosolic Gpx and thioredoxin reductase (TrxR) activity were measured in the liver (biopsies/post-mortem). Se, Gpx, TrxR, glutathione-S-transferase-alpha (aGST) and iodothyronine deiodinase (Dio1) were analysed in the kidney, heart muscle and thyroid. Relative mRNA expression of hepatic aGST1 and Gpx1 was determined. Improvement of Se supply strongly increased serum and liver Se concentration within 10 and 20 days, respectively followed by a plateau. Whereas the achievement of a maximum whole blood Gpx activity was reached after 3 months, serum Gpx3 activity increased with high variations. Hepatic Gpx activity reached a maximum during days 100-200, decreasing thereafter. Distinct group differences in Se and cytosolic Gpx activity were evident in all organs (except Se in kidney). TrxR and Dio1 activity was affected only in the liver. The Se- sheep showed an ongoing decrease in serum Se concentration within 2 years, whereas liver Se remained almost unaffected. High relative Gpx1 mRNA expression in the Se+ group was consensual to high hepatic Gpx activity. Relative mRNA expression of hepatic aGST1 was higher in the Se- sheep. Clinical signs and abnormalities in routine biochemistry were absent. In summary, the best biomarker of Se deprivation and nutritional Se upgrade, respectively was Se in serum. Moreover, hepatic Se concentrations reliably reflected the upgrade of Se supply within days. Whole blood Gpx reacts slowly depending on newly formed erythrocytes restricting its diagnostic use. Vital organs are affected by Se deficiency due to a decrease of cytosolic Gpx activity attenuating the antioxidative system. Cellular up-regulation of aGST1 mRNA expression in the Se- group is assumed to partially compensate for the decreased antioxidant defence due to a loss in Gpx activity. This sheep model appears advantageous for long-term studies on sub-clinical metabolic effects in experimental modifiable nutritional Se supply.

Because dietary intakes of some minerals (including trace elements), especially iron (Fe), are insufficient for the needs of the general Japanese population, accurate estimation of mineral intake is important. This capability is especially necessary to preserve the health of Japanese children. Therefore, the current version of food composition tables (FCT) in Japan was evaluated for validity as tools to estimate dietary intake of minerals for children. For this purpose, 24h food duplicate samples were collected from 292 pre-school children in Miyagi prefecture, Japan. From the weights of items and food codes, intakes of nine minerals were estimated taking advantage of the FCT. In parallel, amounts of minerals in each duplicate samples were instrumentally measured by ICP-AES for Ca, Cu, Fe, Mg, Mn, P and Zn, and by flame AAS for K and Na, both after wet-ashing. The distributions of the mineral amounts were essentially normal. The comparison of the FCT-based estimates (E) and instrumental measures (M) showed that the E/M ratio was close to 1 for Ca, K, Mn, P and Zn, suggesting that E may be a surrogate of M for Ca, K, Mn, P and Zn on a group basis. The ratio being larger than 1.2 for Cu, Fe, Mg and Na indicates that a risk of over-estimation exists when E is relied upon in place of M. On an individual basis, significant differences were detected for all 9 minerals suggesting that the use of E as a surrogate for M should be practiced with care for the estimation of mineral intake.

We aimed to examine the presence of Zn, a trace element, in osteoarthritis (OA) cartilage and meniscus from patients undergoing total knee joint replacement for primary OA. We mapped Ca(2+) and Zn(2+) at the mesoscopic scale by X-ray fluorescence microanalysis (μX-ray) to determine the spatial distribution of the 2 elements in cartilage, μX-ray absorption near edge structure spectroscopy to identify the Zn species, and μX-ray diffraction to determine the chemical nature of the calcification. Fourier transform infrared spectroscopy was used to determine the chemical composition of cartilage and meniscus. Ca(2+) showed a heterogeneous spatial distribution corresponding to the calcifications within cartilage (or meniscus) or at their surface. At least 2 Zn(2+) species were present: the first may correspond to Zn embedded in protein (different Zn metalloproteins are known to prevent calcification in biological tissues), and the second may be associated with a Zn trap in or at the surface of the calcification. Calcification present in OA cartilage may significantly modify the spatial distribution of Zn; part of the Zn may be trapped in the calcification and may alter the associated biological function of Zn metalloproteins.