Influence of some experimental factors on metal toxicity to Selenastrum capricornutum

Toxic effects of Cd⁺⁺, Cu⁺⁺, and Zn⁺⁺ on Selenastrum capricornutum were evaluated in various experimental conditions in order to determine the influence of the composition of the test medium and of the concentration of the algal biomass on the toxicity of metals to algae. Four media recommended in different standard methods (International Standards Organisation, U.S. Environmental Protection Agency, Organisation for Economic Cooperation and Development, AFNOR) were compared. Results of algal bioassays showed that the sensitivity of algae during the exponential growth phase was not influenced by the concentration of macronutrients in the medium. On the contrary, the numeration of the algal suspensions tested appeared determinant as the toxicity decreased when the quantity of algal inoculum was increased: with inocula of nearly 3 × 10⁴, 2.5 × 10⁵, 6 × 10⁵, and 3 × 10⁶ cells/mL at t = 0, the corresponding EC₅₀ were 46, 80, 110, and up to 300 μg/L for cadmium, 10, 65, 105, and 280 μg/L for copper, and 90, 163, 225, and 365 μg/L for zinc. Modifications in the speciation forms of the metal induced by a rapid increase of the pH could be responsible for part of this decreased toxicity.     

Inducibility of metallothionein biosynthesis in the whole soft tissue of zebra mussels Dreissena polymorpha exposed to cadmium,copper, and pentachlorophenol

Freshwater mussels Dreissena polymorpha (Pallas, 1771) were exposed to the elevated concentrations of Cd (10, 50, 100, and 500 μg/L), Cu (10, 30, 50, and 80 μg/L), and an organochlorinated pesticide, pentachlorophenol (PCP) (1, 10, and 100 μg/L). Induced synthesis of biomarker metallothionein (MT) and changes in concentrations of cytosolic Cd, Cu, and Zn in the whole soft tissue of mussels were monitored after a 7‐day laboratory exposure to the contaminants. A clear dose‐dependent elevation in the MT concentration was observed after exposure to Cd at doses of 10–100 μg/L, and this increase of MT content was accompanied with a linear increase of cytosolic Cd. Cd concentration of 500 μg/L caused no additional increase of MT and Cd in mussel cytosol, suggesting possible toxic effects due to exceeding cellular inducible/defense capacity. Cu exposure resulted with variable changes in MT concentrations, with no clear linear relationship between MT and Cu concentrations in water, although a progressive dose‐dependent accumulation of Cu in the soluble fraction of mussel tissues was recorded. A decrease of cytosolic Zn was evident at higher exposure concentrations of both metals used. PCP in concentrations applied was unable to induce MT synthesis, but the higher concentrations of PCP influenced the cytosolic metal concentrations. In conclusion, the results obtained confirm the specificity of MT induction in D. polymorpha as an biological response on metal stimulation, especially by cadmium, being more closely correlated to MT than copper within the ecologically relevant concentration range. The strong induction potential of cadmium as well as an absence of MT induction following exposure to PCP as an organic chemical contaminant are supporting evidences for usage of zebra mussel MT as a specific biomarker of Cd exposure in biomonitoring programs. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.     

Production and purification of the positron emitter zinc‐63

This study presents the production and purification of the positron emitting radionuclide ⁶³Zn. A natural copper target was irradiated with 13.5 MeV protons, and ⁶³Zn was purified by cation exchange chromatography using 0.05 N HCl‐85% acetone as eluent. The production yield reached 1.41 ± 0.19 GBq/μA?h at the end of bombardment and 169 ± 30 MBq/μA·h after purification, with more than 99.9% of radionuclidic purity with copper content around 0.04 μg/g. Copyright © 2011 John Wiley & Sons, Ltd.     

Diesel exhaust particulates affect cell signaling,mucin profiles,and apoptosis in trachea explants of Balb/C mice

Particulate matter from diesel exhaust (DEP) has toxic properties and can activate intracellular signaling pathways and induce metabolic changes. This study was conducted to evaluate the activation of extracellular signal‐regulated kinase (ERK) and c‐Jun N‐terminal kinase (JNK) and to analyze the mucin profile (acid (AB⁺), neutral (PAS⁺), or mixed (AB/PAS⁺) mucus) and vacuolization (V) of tracheal explants after treatment with 50 or 100 μg/mL DEP for 30 or 60 min. Western blot analyses showed small increases in ERK1/2 and JNK phosphorylation after 30 min of 100 μg/mL DEP treatment compared with the control. An increase in JNK phosphorylation was observed after 60 min of treatment with 50 μg/mL DEP compared with the control. We did not observe any change in the level of ERK1/2 phosphorylation after treatment with 50 μg/mL DEP. Other groups of tracheas were subjected to histological sectioning and stained with periodic acid‐Schiff (PAS) reagent and Alcian Blue (AB). The stained tissue sections were then subjected to morphometric analysis. The results obtained were compared using ANOVA. Treatment with 50 μg/mL DEP for 30 min or 60 min showed a significant increase (p < 0.001) in the amount of acid mucus, a reduction in neutral mucus, a significant reduction in mixed mucus, and greater vacuolization. Our results suggest that compounds found in DEPs are able to activate acid mucus production and enhance vacuolization and cell signaling pathways, which can lead to airway diseases. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1297–1308, 2015.     

Occurrence of Ochratoxin A in Southern Spanish Generous Wines under the Denomination of Origin "Jerez-Xérès-Sherry and 'Manzanilla' Sanlúcar de Barrameda"

The mycotoxin ochratoxin A (OTA) has toxic effects in animals; the most relevant of them is nephrotoxicity. OTA has also been classified as a possible carcinogen for humans (group 2B) by the International Agency for Research on Cancer (IARC). Therefore, exposure to OTA through contaminated food can represent health impairment to humans. The maximum permitted level for this mycotoxin in wine is 2.0 μg/L. The presence of OTA in Spanish wines produced using the traditional methods under the Denomination of Origin "Jerez-Xérès-Sherry andmanzanilla Sanlúcar de Barrameda" was evaluated by a High performance Liquid Chromatography method with fluorescence detection and immunoaffinity column purification. A recovery of 95.4% and a limit of detection and quantification of 0.009 μg/L and 0.02 μg/L respectively, were achieved. In manzanilla, fino, amontillado and oloroso wine, the mean OTA values were 0.042, 0.044, 0.144, and 0.319 μg/L, respectively. These levels are not different from other data given in the reference literature on white wines, although fino and manzanilla wines have very low OTA levels.     

Single and interactive effects of the antifouling booster herbicides diuron and Irgarol 1051 on photosynthesis in the marine cyanobacterium, Arthrospira maxima

Diuron and Irgarol 1051 are widely used antifouling booster herbicides to control the growth of redundant algae on submerged structures. They pose serious threats to the marine ecosystem especially on the non-target algal species which is of serious environmental concern. In the present study, the acute (1 h) individual and joint toxicities of the foresaid herbicides were assessed in the economically important cyanobacterium Arthrospira maxima, using robotic chlorophyll a (Chl a) fluorescence imaging method. When tested individually, Diuron was found to be more toxic to photosynthesis than Irgarol 1051, with median effective concentration (EC₅₀) values of 4.96–9.51 μg L^?1 and 7.15–14.80 μg L^?1, respectively. The most sensitive endpoint was the effective quantum yield (Y (II)) of photosystem II (PSII) for Diuron and the relative maximum electron transport rate (rETR_max) for Irgarol 1051. Mixture toxicity of Diuron and Irgarol 1051 was evaluated based on a factorial design with two factors at two levels, considering Y (II) as the sensitive biomarker. There were additive effects when low concentration of Irgarol 1051 (6.5 μg L^?1) was mixed with high and low concentrations of Diuron (5 μg L^?1 and 2.5 μg L^?1, respectively), with ratio of inhibition (RI) being 1.07±0.17 and 0.92±0.13, respectively. In contrast, high concentration of Irgarol 1051 (13 μg L^?1) resulted in antagonistic effects when added to low and high concentrations of Diuron, showing RI values of 0.89±0.03 and 0.81±0.06, respectively. The observations presented here indicate the need of consideration of interactive mode of action in evaluating herbicide toxicities in natural waters.     

THE NOVEL MARINE NATURAL PRODUCT PLOCAMADIENE A CAUSES HISTAMINE RELEASE FROM MAST CELLS OF THE GUINEA-PIG AND RAT IN VITRO

1. Plocamadiene A is a polyhalogenated monoterpene, (1R, 2S, 4S, 1′E)-2-bromo-l-chloro-4-(2′-chloroethenyl)-I-methyl-5-methylenecyclohexane, isolated from red marine algae of the Plocamium genus. 2. This study examined the activity of plocamadiene A on guinea-pig isolated ileum (GPI) and subsequently on rat isolated peritoneal mast cells. 3. Plocamadiene A (1 μg/mL) produced a slow onset, sustained contraction of the GPI. This was insensitive to atropine (1 μmol/ L) and tetrodotoxin (1 μmol/ L), but was significantly reduced by H₁-histamine receptor antagonists including mepyramine (10 nmol/L), chlorcyclizine (10 nmol/L) and diphenhydramine (0.1 μmol/L). The H₂-histamine receptor antagonists cimetidine (0.1 μmol/L) and ranitidine (10 nmol/L) potentiated the response to plocamadiene A (1 μg/mL). 4. The amplitude of contraction caused by plocamadiene A (1 μg/mL) gradually decreased when the compound was applied repeatedly to the GPI for 5 min every 10 min for 150 min. 5. Contractions to plocamadiene A (1 μg/mL) were reduced to approximately 66% of the time control in ovalbumin-sensitized GPI challenged with ovalbumin to release endogenous contractile agents. 6. Cromolyn (0.1 mmol/ L) inhibited (by 40%) the response in the GPI caused by plocamadiene A (1 μg/mL) as compared with time controls. 7. Spectrofluorometric assay suggested that both plocamadiene A (10 μg/mL) and compound 48/80 (10 μg/mL) caused histamine release from rat peritoneal mast cells in vitro. This release of histamine was reduced by cromolyn (100 μg/mL). 8. This study concluded that plocamadiene A releases histamine from mast cells of the GPI and peritoneal mast cells in the rat.     

In vitro Toxicity of Cobalt and Hard Metal Dust in Rat and Human Type II Pneumocytes

Abstract: It has been demonstrated that hard metal dust, which consists of a mixture of cobalt and tungsten carbide, is more toxic toward mouse peritoneal and rat alveolar macrophages than pure cobalt (Co) or tungsten carbide (WC). The aim of this study was to investigate the toxic effects of Co and hard metal dust on alveolar epithelial type II cells (AT-II), and to compare these with alveolar macrophages. Freshly isolated rat and human AT-II and rat alveolar macrophages were exposed for 18 hr to particles of Co, WC or Co/WC. As an index for cell toxicity, release of lactate dehydrogenase was measured. For rat AT-II, TD₅₀ values per 10⁵ cells were 672 μg (95% C.I. = 264-1706 μg) for pure Co and 101 μg (95% C.I. = 59-172 μg) for Co in Co/WC mixture. For rat alveolar macrophages, TD₅₀ values per 10⁵ cells were 18 μg (95% C.I.=15-24 μg) for pure Co and 5 μg (95% C.I. = 5-6 μg) for Co in Co/WC mixture. WC only caused an increase in lactate dehydrogenase at high concentrations. No toxicity was found in human AT-II for either Co, WC or Co/WC. These results indicate that 1) rat AT-II are less sensitive to Co than rat alveolar macrophages, 2) human AT-II are less sensitive to Co than rat AT-II, 3) the toxicity of Co is increased by the presence of WC.     

Interactions of copper and manganese: A mechanism by which manganese alleviates copper toxicity to the marine diatom, Nitzschia closterium (Ehrenberg) W. Smith

The mechanism by which manganese (4.2 and 42 μg Mn·1^?1) ameliorates the toxicity of copper (0–60 μg Cu·1^?1) to the marine diatom, Nitzschia closterium (Ehrenberg) W. Smith, was investigated using unsupplemented sea water for growth rate experiments. Speciation of manganese associated with the cellls, intracellular and extracellular manganese and copper concentrations, and competitive binding between copper and manganese were studied using ultrafiltration, anodic stripping voltammetry and radiochemical techniques.Cells cultured before the sea-water assay and in the absence of manganese accumulated high intracellular copper, and their growth rate was more sensitive to copper than cells cultured in the presence of manganese. Manganese associated with the cells was present as manganese (II) and/or (III) hydroxides, rather than as the fully oxidized MnO₂. It is proposed that manganese (III) hydroxide, like iron (III) hydroxide and cobalt (III) hydroxide, adsorbs copper very effectively on the membrane surface and prevents its penetration into the cell. Competitive interactions between manganese and copper occurred at the cell surface, but copper had no effect on intracellular manganese. Only 4 μg Mn·1^?1 was required to alleviate copper toxicity, compared to 790 μg Fe·1^?1. In the presence of algae, copper ions had a greater affinity for manganese in sea water than iron at similar concentrations, which may partially account for the relative effectiveness of manganese as a protective agent. In addition, manganese can scavenge the toxic superoxide radical (O₂^?), catalyzing its dismutation to H₂O₂ and O₂.Manganese was unable to reverse copper toxicity, nor did it inhibit the toxicity of lipid-soluble copper complexes, such as copper oxinate, to N. closterium.     

Methotrexate Elimination in a Patient with an Orthotopic Neobladder with and without a Urethral Catheter

Placement of a urethral catheter has been recommended to ensure adequate methotrexate elimination in patients with a neobladder; however, the need for this and its impact on methotrexate elimination have not been determined. A 53-year-old man with a cecal continent urinary diversion received intravenous methotrexate 30 mg/m² on two occasions, with and without urethral catheter drainage of the neobladder. Serum methotrexate concentrations declined at a rate that resulted in 24- and 48-hour values falling below the accepted toxic concentration threshold of 5–50 μmol/L and 0.05 μmol/L, respectively. In this man, who received low-dose methotrexate, catheterization of the neobladder did not alter methotrexate elimination sufficiently to justify its cost, risk, and inconvenience.     

Effects of tetrabrombisphenol A on DNA integrity,oxidative stress,and sterlet (Acipenser ruthenus) spermatozoa quality variables

The sperm of sterlet (Acispenser ruthenus) was used to investigate the effect of the xenobiotic tetrabrombisphenol A (TBBPA) on sperm quality variables (ATP content, spermatozoa motility, and velocity), DNA integrity, and oxidative stress indices. Sperm was diluted to obtain a spermatozoa density of 5 × 10⁸ cells/mL and exposed for 2 h to final concentrations of TBBPA (0.5, 1.75, 2.5, 5, and 10 μg/L). The oxidative stress indices, including lipid peroxidation, carbonyl derivatives of proteins, and antioxidant activity were significantly higher with increased concentrations of TBBPA. There was significantly less intracellular ATP in sperm samples at TBBPA concentrations of 2.5 μg/L and above. Spermatozoa velocity and percent motile sperm were significantly lower at each sampling time post‐activation compared to controls. DNA damage expressed as percent DNA in Tail and Olive Tail moment was significantly higher with exposures ≥2.5 μg/L TBBPA. The results demonstrated that TBBPA and other xenobiotics can induce reactive oxygen species stress in fish spermatozoa, which could impair the sperm quality, DNA integrity, ATP content, and the antioxidant defense system. This study confirmed that fish spermatozoa can be used in in vitro assays for monitoring residual pollution in aquatic environments. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 735–745, 2015.     

Graphene oxide quantum dot exposure induces abnormalities in locomotor activities and mechanisms in zebrafish (Danio rerio)

Graphene oxide quantum dots (GOQDs) have broad applications such as bioimaging and drug delivery, among others, even expanding into the aquatic environment. However, reports on the adverse effects of GOQDs on fish development are limited. In this study, we exposed zebrafish embryos to GOQDs for 7 days after fertilization and found that GOQDs exposure at low concentrations (12.5, 25, 50 or 100 μg/L) decreased the total distance and the mean velocity of larvae movement. Additionally, the GOQDs significantly reduced the enzyme activity related to energy supply and locomotor capacity, including Ca²⁺-ATPase in the 12.5, 25, 50 and 100 μg/L GOQDs groups and Na⁺/K⁺-ATPase in the 25 and 50 μg/L GOQDs groups. Moreover, GOQD exposure altered the mRNA expression of genes involved in energy supply and calcium transport. The levels of the atp2a2b, atp2a1, and cacna1sb genes were significantly downregulated in the 25, 50 and 100 μg/L GOQDs groups, and ryr3 expression was significantly reduced in the 25 and 50 μg/L GOQDs groups. The expression level of cacna1c was significantly upregulated in the 50 and 100 μg/L GOQDs groups. In summary, GOQD exposure induced a decrease in locomotor capacity in zebrafish, which may be due to the reduction of Ca²⁺-ATPase and Na⁺/K⁺-ATPase activity levels, and dysregulated expression of the genes involved in energy metabolism and calcium transport. Our study provides novel insight into the effects of GOQDs on the embryonic development of fish, which will be useful for the development of environment-friendly GOQDs that reduce the potential hazard to aquatic species.     

ENDOTHELIAL DYSFUNCTION EXACERBATES THE IMPAIRMENT OF RELAXATION BY LYSOPHOSPHATIDYLCHOLINE IN PORCINE CORONARY ARTERY

1. Current evidence suggests that lysophosphatidylcholine (LPC), a component found in oxidized low-density lipoprotein (Ox-LDL), inhibits endothelium-dependent relaxation (EDR) mediated by endothelium-derived relaxing factor (EDRF) and endothelium-derived hyperpolarizing factor (EDHF). An objective of the present study was to characterize the roles of the different elements of EDR in LPC-induced impairment within the porcine coronary artery. Concomitantly, we sought to determine whether impairment of one component of EDR would increase the sensitivity of the endothelium to LPC. 2. Bradykini. (0.1 nmol/L-0.3 μmol/L) relaxed U46619 (30 nmol/L)-precontracted porcine coronary artery rings in a concentration-dependent manner. A reduction in the bradykinin-elicited response was observed in N^G-nitro-L-arginine methyl ester (L-NAME; 300 μmol/L)- and ouabain (50 μmol/L)-treated rings. Pretreatment with LPC (20 μmol/L), which on its own had no effect on normal endothelial relaxation, resulted in further inhibition of EDRF- and EDHF-induced relaxations. 3. Our results demonstrate that EDRF and EDHF are the primary mediators of EDR in the porcine coronary artery. Our data also show that while a low concentration of LPC (20 μmol/L) does not impair EDR, it can evoke vascular dysfunction following blockade of either the effects of EDRF or EDHF. Therefore, these data suggest that the partially damaged vascular endothelium could be more sensitive to threshold levels of this atherogenic phospholipid.     

Bioavailability of sediment-associated Cu and Zn to Daphnia magna

Exposures to mining-impacted, field-collected sediment (Clear Creek, CO, USA) contaminated with Cu (2.4 mg/g) and Zn (5.2 mg/g) were acutely toxic to juvenile Daphnia magna. Dissolved Cu and Zn in the overlying water (sediment+reference water) were at levels that could cause acute toxicity. To reduce dissolved metals below toxic levels, the sediment was repeatedly rinsed to remove any easily mobilized metals. Washing the sediment reduced dissolved Cu by 60% and Zn by 80%. D. magna exposed to washed sediment experienced higher survival (95%) compared to those exposed to the original sediment (<50%). Cu and Zn that remained associated with suspended sediment after washing were not bioavailable, since survival and tissue metal concentrations in D. magna exposed to both filtered (>0.45 microm) and unfiltered overlying water were statistically similar. Multiple regression analysis indicated that only dissolved Cu significantly contributed to mortality of D. magna whereas particulate Cu, particulate Zn, and dissolved Zn did not. Regression analysis on a combined dataset from all Clear Creek exposures (washed and unwashed), revealed a significant (p < 0.0001, r(2) = 0.76) relationship between the concentration of dissolved copper in the overlying water and the mortality of exposed Daphnia, yielding an estimated LC50 of 26 microg/L dissolved copper (hardness approximately 140 mg/L). The results of this study indicate that if the sediment of Clear Creek was subjected to a resuspension event that there would be a significant efflux of metals from the sediment into the water column, resulting in potentially toxic levels in the water column.     

Toxicity of intravitreal miconazole in dmso

Abstract

The ocular toxicity of intravitreal miconazole nitrate dissolved in DMSO was determined in rabbits by slit lamp biomicroscopy and indirect ophthalmoscopy after pupillary dilation with atropine 1 % eye drops. Slit lamp examination of the eyes revealed no evidence of toxic injury to the conjunctiva, cornea, lens, or vitreous body of any of the test eyes at the dosage levels tested. Electroretinographic testing revealed no toxic effects to the retina with balanced salt solution control or DMSO control intravitreal injections as well as doses of 2.5,5, and 10–30 /μg miconazole nitrate in DMSO after the 2-month observation period. Histopathologic examination by light and electron microscopy revealed no damage to the retina, retinal pigment epithelium, or choroid at doses ranging from 2.5 to 30 μg. This study shows that intravitreal injections of up to 30 μg of intravitreal miconazole nitrate dissolved in DMSO can be tolerated without ocular toxicity in the rabbit.     

Natural Products: Anti-proliferative Effects of Lichen-derived Inhibitors of 5-Lipoxygenase on Malignant Cell-lines and Mitogen-stimulated Lymphocytes

Several lichen species have been used traditionally as medicinal plants. It has previously been shown that two low-molecular-weight lichen metabolites, lobaric acid isolated from Stereocaulon alpinum Laur. and protolichesterinic acid isolated from Cetraria islandica L. (Ach.), have in-vitro inhibitory effects on arachidonate 5-lipoxygenase. We have studied the effects of these compounds on cultured cells from man, including three malignant cell-lines (T-47D and ZR-75-1 from breast carcinomas and K-562 from erythro-leukaemia), as well as normal skin fibroblasts and peripheral blood lymphocytes. Both test substances caused a significant reduction in DNA synthesis, as measured by thymidine uptake, in all three malignant cell-lines; the dose inducing 50% of maximum inhibition (ED50) was between 1.1 and 24.6 μg mL^?1 for protolichesterinic acid and between 14.5 and 44.7 μg mL^?1 for lobaric acid. The breast-cancer cell-lines were more sensitive than K-562. The proliferative response of mitogen-stimulated lymphocytes was inhibited with a mean ED50 of 8.4 μg mL^?1 and 24.5 μg mL^?1 for protolichesterinic acid and lobaric acid, respectively. These concentrations are of the same order of magnitude as the IC50 values in the 5-lipoxygenase assay. Significant cell death (assessed by the MTS (3–4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and trypan blue exclusion) occurred in the three malignant cell-lines at protolichesterinic acid and lobaric acid concentrations above 20 and 30 μg mL^?1, respectively. In K-562 morphological changes consistent with apoptosis were detected. Up to 38% cell death was observed at 20 μg mL^?1 for protolichesterinic acid and 15 μg mL^?1 for lobaric acid in mitogen-stimulated lymphocytes but unstimulated lymphocytes were clearly less sensitive. In contrast, the DNA synthesis, proliferation and survival of normal skin fibroblasts were not affected at doses up to 20 μg mL^?1 for protolichesterinic acid and 30 μg mL^?1 for lobaric acid. We conclude that the anti-proliferative and cytotoxic effects observed might be related to the 5-lipoxygenase inhibitory activity of protolichesterinic acid and lobaric acid. These results open up the opportunity for future studies of these lichen metabolites with regard to their anti-tumour and anti-inflammatory properties.     

Three approaches to the analysis of zinc(II) in pharmaceutical formulations by means of different spectrometric methods

The present paper constitutes three different spectral methods A, B and C developed with the purpose of determining precisely the concentrations of zinc(II), either in various ophthalmic solutions (collyria) or in insulin injections. Method A is a spectrophotometric one, based on the formation of the chelate complex of Zn(II) to be analysed with 4-(2-pyridylazo)-resorcinol(PAR) at pH 8.07±0.01 and in a micellar medium produced by the non-ionic surfactant Triton X-100. This chelate complex shows a λ_max at 493 nm, an apparent molar absorptivity ϵ=77728 l/mol per cm and a corresponding Sandell’s sensitivity of S_s=0.84 ng cm⁻². The concentration of Zn(II) examined is calculated from the regression line equation: A=1.143C+0.029 (r=0.9998, n=25) with an optimum concentration range of 0.18–2.0 μg/ml. Method B exploits the fluorescence intensity of the 8-hydroxyquinolate chelate complex of Zn(II) to be analysed, measured at λ_emission=510 nm (λ_excitation=420 nm). The concentration of Zn(II) examined is calculated from the regression line equation: A=0.25C+0.17 (r=0.9996, n=18), with an optimum concentration range of 0.26–1.05 μg of Zn(II)/ml. The third method C is an AAS method, based on the following analytical parameters: λ=213.9 nm; hollow cathode lamp (HCL): L1788-30NB; HCL current 18 mV; flame temperature 2700°K. The concentration of Zn(II) analysed is calculated from the regression line equation: A=1.499C−7.409×10⁻⁴ (r=0.9996, n=25), with an optimum concentration range of 0.2–1.2 μg/ml. The accuracy and the precision of the proposed methods A, B and C was experimentally investigated and proved to be very satisfactory. On the other hand, the methods described were successfully applied for the determination of the Zn(II) included in four eye drop solutions and in one insulin injection both provided by the pharmaceutical market. The analytical results of the afore-cited formulations were summarised in a comparative table and were considered to be very satisfactory.     

The association between active/passive smoking and toxic metals among pregnant women in Greece

Exposure to toxic metals during pregnancy may have detrimental effects on foetal development. We assessed the role of sociodemographic characteristics and active and passive smoking on blood concentrations of metals (As, Cd, Pb, Hg, Sb, U, Mn and Mo). Venous blood drawn from 50 pregnant women, randomly selected from the mother-child birth cohort 'Rhea'. Extensive questionnaire data on active and passive smoking were collected. Urinary cotinine was measured to validate self-reported exposure and non-smoking status. Smokers had higher concentrations of Cd (1.0 μg/L) as compared with non-smokers (0.29 μg/L, P?相似文献