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1.
J Dairy Sci ; 100(3): 2375-2380, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28088425

RESUMO

Mastitis is the most common disease in dairy herds worldwide and is often caused by Staphylococcus aureus. Little is known about the effect of mastitis on transporters in the mammary gland and the effect on transporter-mediated secretion of drugs into milk. We studied gene expressions of ATP-binding cassette and solute carrier transporters in S. aureus-infected mammary glands of mice. On d 7 of lactation, NMRI mice were inoculated with 1,000 cfu of S. aureus in 2 mammary glands and with a saline vehicle in 2 control glands. Gene expression of the transporters, Bcrp, Mdr1, Mrp1, Oatp1a5, Octn1, and Oct1, and of Csn2, the gene encoding ß-casein, were determined in mammary glands at 72 h after treatment. As biomarkers of the inflammatory response gene, expressions of the cytokines Il6, Tnfα, and the chemokine Cxcl2 were measured. Despite a high individual variation between the 6 animals, some characteristic patterns were evident. The 3 inflammatory biomarkers were upregulated in all animals; Csn2 was downregulated compared with controls in all animals, although not statistically significantly. Both Mrp1 and Oatp1a5 were statistically significantly upregulated and Bcrp was downregulated. Gene expression of Bcrp followed the expression of Csn2 in each of the animals, indicating a possible co-regulation. The findings demonstrate that S. aureus infection has an effect on expression of drug transporters in the mammary gland, which may affect secretion of drugs into milk and efficacy of drug therapy.


Assuntos
Glândulas Mamárias Animais/metabolismo , Staphylococcus aureus , Animais , Biomarcadores/metabolismo , Bovinos , Feminino , Regulação da Expressão Gênica , Camundongos , Infecções Estafilocócicas/genética
2.
Food Chem Toxicol ; 91: 36-41, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26945613

RESUMO

Prochloraz is widely used in horticulture and agriculture, e.g. as a post-harvest anti-mold treatment. Prochloraz is a known endocrine disruptor causing developmental toxicity with multiple mechanisms of action. However, data are scarce concerning other toxic effects. Since oxidative stress response, with formation of reactive oxygen species (ROS), is a common mechanism for different toxic endpoints, e.g. genotoxicity, carcinogenicity and teratogenicity, the aim of this study was to investigate if prochloraz can induce oxidative stress and/or DNA damage in human cells. A cell culture based in vitro model was used to study oxidative stress response by prochloraz, as measured by the activity of the nuclear factor erythroid 2-related factor 2 (Nrf2), a key molecule in oxidative defense mechanisms. It was observed that prochloraz induced oxidative stress in cultured human adrenocortical H295R and hepatoma HepG2 cells at non-toxic concentrations. Further, we used Comet assay to investigate the DNA damaging potential of prochloraz, and found that non-toxic concentrations of prochloraz induced DNA damage in HepG2 cells. These are novel findings, contradicting previous studies in the field of prochloraz and genotoxicity. This study reports a new mechanism by which prochloraz may exert toxicity. Our findings suggest that prochloraz might have genotoxic properties.


Assuntos
Dano ao DNA/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Imidazóis/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Células Hep G2 , Humanos , Técnicas In Vitro
3.
Hum Exp Toxicol ; 34(11): 1106-18, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25645824

RESUMO

Alcohol consumption and increased estrogen levels are major risk factors for breast cancer, and peroxisome proliferator-activated receptor γ (PPAR-γ) plays an important role in alcohol-induced breast cancer. PPAR-γ activity is inhibited by ethanol, leading to increased aromatase activity and estrogen biosynthesis ultimately leading to breast cancer. If other organic solvents inhibit PPAR-γ activity, they should also lead to increased oestrogen biosynthesis and thus be potential breast carcinogens. Ten commonly used hydrophilic organic solvents were first tested in a cell-based screening assay for inhibitory effects on PPAR-γ transactivation. The chemicals shown to inhibit PPAR-γ were tested with vectors encoding PPAR-γ with deleted AB domains and only the ligand-binding domain to rule out unspecific toxicity. Next, the effects on biosynthesis of estradiol, testosterone and oestrone sulphate were measured in the H295R steroidogenesis assay after incubation with the chemicals. Ethylene glycol, ethyl acetate, and dimethyl sulphoxide inhibited PPAR-γ transactivation in a dose-dependent manner. The inhibitory effect on PPAR-γ was specific for PPAR-γ since the AB domain of PPAR-γ was required for the inhibitory effect. In the second step, ethylene glycol significantly increased production of oestradiol by 19% (p < 0.05) and ethyl acetate inhibited production of testosterone (p < 0.05). We here show that screening of 10 commonly used organic solvents for the ability to inhibit PPAR-γ transactivation followed by a well-established steroidogenesis assay for production of sex hormones in exposed H295 R cells may provide a screening tool for potential breast carcinogens. This initial screening thus identified ethylene glycol and possibly ethyl acetate as potential breast carcinogens.


Assuntos
Carcinógenos/farmacologia , PPAR gama/antagonistas & inibidores , Solventes/farmacologia , Acetatos/farmacologia , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Estradiol/metabolismo , Estrona/metabolismo , Etilenoglicol/farmacologia , Células HEK293 , Humanos , PPAR gama/genética , Testosterona/metabolismo , Ativação Transcricional/efeitos dos fármacos
4.
Regul Toxicol Pharmacol ; 65(1): 7-11, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23211416

RESUMO

The French Agency for Food, Environmental and Occupational Health and Safety (Anses) hosted a two-day workshop on Endocrine Disruptors: Exposure and Potential Impact on Consumers Health, bringing together participants from international organizations, academia, research institutes and from German, Swedish, Danish and French governmental agencies. The main objective of the workshop was to share knowledge and experiences on endocrine disruptors (ED) exposure and potential impact on consumers' health, to identify current risk assessment practices and knowledge gaps and issue recommendations on research needs and future collaboration. The following topics were reviewed: (1) Definition of ED, (2) endpoints to be considered for Risk assessment (RA) of ED, (3) non-monotonic dose response curves, (4) studies to be considered for RA (regulatory versus academic studies), (5) point of departure and uncertainty factors, (6) exposure assessment, (7) regulatory issues related to ED. The opinions expressed during this workshop reflect day-to-day experiences from scientists, regulators, researchers, and others from many different countries in the fields of risk assessment, and were regarded by the attendees as an important basis for further discussions. Accordingly, the participants underlined the need for more exchange in the future to share experiences and improve the methodology related to risk assessment for endocrine disrupters.


Assuntos
Disruptores Endócrinos/toxicidade , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/toxicidade , Animais , Relação Dose-Resposta a Droga , Disruptores Endócrinos/administração & dosagem , Poluentes Ambientais/administração & dosagem , Humanos , Cooperação Internacional , Saúde Pública , Medição de Risco/métodos
5.
Toxicol Lett ; 201(1): 80-5, 2011 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-21167921

RESUMO

Maternal cadmium (Cd) exposure during lactation causes neurobehavioral effects in the suckling offspring as well as involution like disturbances in the mammary glands of rodents. The aim of the present study was to examine Cd-induced effects in secreting mammary epithelial cells in relation to calcium (Ca) transport and ß-casein expression. Reduced protein expression of secretory pathway Ca-ATPase (SPCA) was revealed in the mammary glands of lactating mice exposed to Cd during peak lactation. In concordance, SPCA gene expression was down regulated and total intracellular Ca levels reduced in murine mammary epithelial HC11 cells treated with Cd for 72 h. Cd reduced ß-casein gene expression in a concentration dependent manner in the HC11 cells. Our findings on Cd-induced reduction of Ca levels, SPCA and ß-casein expression in the mammary epithelium resemble the effects observed in the mammary glands as a result of forced weaning. In conclusion, maternal Cd exposure during lactation may disturb Ca regulation and decrease the levels of ß-casein in milk with potential nutritional and developmental implications for the breast-fed newborn.


Assuntos
Cádmio/toxicidade , ATPases Transportadoras de Cálcio/análise , Cálcio/metabolismo , Caseínas/genética , Homeostase , Glândulas Mamárias Animais/efeitos dos fármacos , Animais , ATPases Transportadoras de Cálcio/genética , Células Cultivadas , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Camundongos , RNA Mensageiro/análise
6.
Environ Res ; 98(2): 215-23, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15820728

RESUMO

Food is the main source of trace elements for the general population. The gastrointestinal absorption of certain trace elements, e.g., cadmium, is strongly influenced by iron (Fe) status. This factor may also be relevant for the bioavailability of other trace elements. Therefore, we investigated relationships between Fe status indicators and trace element concentrations in blood and serum of 234 boys and girls at ages 15 and 17 years. Fe status was measured using serum ferritin (S-Ft), soluble transferrin receptor in serum (sTfR), and the ratio sTfR/S-Ft. The trace elements we investigated were, in blood, cadmium, cobalt, copper, zinc, selenium, rubidium, mercury, and lead, and, in serum, cobalt, copper, zinc, selenium, rubidium, tungsten, mercury, and lead. We found inverse correlations between Fe status and blood cadmium, blood or serum cobalt, or blood copper. There were positive correlations between Fe status and mercury concentrations. Selenium was positively correlated with sTfR. The relationships between Fe status and lead were equivocal. There were fewer correlations for serum than for blood, but the inverse relationships between Fe status and cobalt were equally strong in serum and blood. We found only occasional, and perhaps spurious, correlations with zinc, rubidium, and tungsten. In conclusion, previous indications that cadmium, cobalt, and copper are absorbed by transport mechanisms similar to that of Fe are supported by this study. Strong positive correlations between Fe status and mercury concentrations remain to be explained.


Assuntos
Ferritinas/sangue , Ferro/metabolismo , Receptores da Transferrina/sangue , Oligoelementos/sangue , Adolescente , Disponibilidade Biológica , Feminino , Humanos , Masculino , Espectrometria de Massas
7.
Acta Paediatr ; 92(4): 473-80, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12801116

RESUMO

AIM: To assess whether mean daily intake of copper or maximal concentration of copper in drinking water is related to the incidence of diarrhoea and vomiting among young children. METHODS: Mean daily intake of copper from drinking water was estimated prior to episodes of diarrhoea among 430 children aged 9 to 21 mo. A total of 4703 samples of tap water were collected in the homes of the children. The mean daily intake of copper and the maximal concentration of copper in samples of consumed water were used as measures of exposure. The cumulative incidence of acute diarrhoea and vomiting was studied during 12 wk of follow-up. Cases of diarrhoea caused by viral and bacterial infections were identified. RESULTS: The median copper level of the mean value for each child was 0.61 mg/L with 10th and 90th percentiles of 0.04 and 1.57 mg/L. Among the 430 children, 43 had episodes of acute diarrhoea, of which 23 had no identified viral or bacterial origin, and vomiting was reported in 95 children. No significant associations were found between daily intake of copper or maximal concentration of copper in drinking water and the risk of diarrhoea or vomiting. CONCLUSION: There is unlikely to be a strong association between daily intake of copper or maximal concentration of copper in drinking water and the risk of diarrhoea or vomiting within the range of copper intakes/concentrations studied.


Assuntos
Cobre/efeitos adversos , Cobre/análise , Diarreia Infantil/induzido quimicamente , Vômito/induzido quimicamente , Água/efeitos adversos , Água/química , Fatores Etários , Estudos de Coortes , Cobre/administração & dosagem , Relação Dose-Resposta a Droga , Estudos Epidemiológicos , Feminino , Humanos , Lactente , Masculino , Fatores de Risco , Suécia , Água/administração & dosagem
8.
Acta Crystallogr C ; 57(Pt 11): 1265-7, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11706243

RESUMO

The Pd atom in each of the two title compounds, [Pd(NO(3))(2)(C(2)H(6)OS)(2)], (I), and [Pd(NO(3))(2)(C(4)H(8)OS)(2)], (II), coordinates two O atoms from two nitrate ligands and two S atoms from dimethyl sulfoxide (dmso) and thioxane (systematic name: 1,4-oxathiane) ligands in a pseudo-square-planar cis-geometry. In the dmso complex, the distances to palladium are Pd-O 2.067 (2) and 2.072 (2) A, and Pd-S 2.2307 (11) and 2.2530 (8) A. The corresponding distances in the thioxane complex are Pd-O 2.053 (3) and 2.076 (2) A, and Pd-S 2.2595 (9) and 2.2627 (11) A. Both compounds may be regarded as dimers with an inversion centre, where one of the coordinating nitrate O atoms in one molecule also interacts with the Pd atom in the adjacent molecule, with Pd-O distances of 2.849 (9) and 3.31 (3) A in (I) and (II), respectively.

9.
J Environ Monit ; 3(5): 531-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11695124

RESUMO

Input of Cd to arable soils occurs mainly through atmospheric deposition and mineral fertilisers. Phosphate fertilisers are often contaminated with Cd. In organic farming the use of mineral fertilisers is restricted. The impact of conventional and organic farming on Cd and Zn levels in tissues from dairy cows was studied. Kidney, liver, muscle and mammary tissue samples were collected at slaughter from 67 cows, aged 30-95 months, in a project with conventional and organic production at the same farm. Samples were analysed by electrothermal atomic absorption spectrometry with a quality control programme. Significantly lower levels of Cd were found in cows from the organic system (n = 29) than from the conventional cows (n = 38) in kidney [330 +/- 100 (mean +/- s) micrograms kg-1 vs. 410 +/- 140], liver (33 +/- 15 vs. 44 +/- 19) and mammary tissue (0.38 +/- 0.14 vs. 0.59 +/- 0.37), while there were no differences in muscle (0.48 +/- 0.13 vs. 0.49 +/- 0.14). Organic cow kidneys had lower Zn levels than conventional cows (19 +/- 1.4 mg kg-1 vs. 20 +/- 2), whereas muscles had higher Zn levels than conventional cows (67 +/- 16 vs. 51 +/- 12). Cd and Zn in mammary tissue were positively related to age and milk production. There was a positive relationship between levels in kidney of Cd and metallothionein (MT) and a Cd/MT concentration ratio indicating protection from Cd-induced renal dysfunction. When older animals, that entered the project as milk-producing cows, were included the differences in kidney and liver Cd levels between the systems were no longer significant, while Cd in kidney became related to age- and production-related parameters. The change of significant relationships when older animals were included shows the importance of controlled conditions for environmental monitoring.


Assuntos
Cádmio/farmacocinética , Bovinos , Monitoramento Ambiental , Zinco/farmacocinética , Fatores Etários , Agricultura , Animais , Mama/química , Cádmio/análise , Feminino , Fertilizantes , Rim/química , Lactação , Fígado/química , Músculo Esquelético/química , Plantas Comestíveis , Zinco/análise
10.
Arch Environ Contam Toxicol ; 40(3): 425-31, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11443376

RESUMO

The main sources of cadmium (Cd) input to soils have been phosphate fertilizers and deposition from air. In organic farming, phosphate fertilizers are not used, which may in the long term result in lower Cd levels. In the present study, feed, kidney, liver, and manure from growing/finishing pigs raised conventionally and organically on the same farm were microwave-digested and analyzed for Cd by graphite furnace atomic absorption spectrometry. Cd was also analyzed in soil and water. A quality control program was included. The organic pigs (n = 40) were raised outdoors and fed an organic feed; the conventional pigs (n = 40) were raised indoors and given a conventional feed. The Cd levels in organic and conventional feed were 39.9 microg/kg and 51.8 microg/kg, respectively. Organic feed contained 2% potato protein, which contributed 17% of the Cd content. Conventional feed contained 5% beet fiber, which contributed 38% of total Cd content. Both feeds contained vitamin-mineral mixtures with high levels of Cd: 991 microg/kg in organic and 589 microg/kg in conventional feed. There was a significant negative linear relationship between Cd concentration in kidney and kidney weight. There was no significant difference in liver Cd levels between organic and conventional pigs and the mean +/- SD was 15.4 +/- 3.0. In spite of the lower level of Cd in the organic feed, the organic pigs had significantly higher levels in kidneys than the conventional pigs, 96.1 +/- 19.5 microg/kg wet weight (mean +/- SD; n = 37) and 84.0 +/- 17.6 microg/kg wet weight (n = 40), respectively. Organic pigs had higher Cd levels in manure, indicating a higher Cd exposure from the environment, such as ingestion of soil. Differences in feed compositions and bioavailability of Cd from the feed components may also explain the different kidney levels of Cd.


Assuntos
Ração Animal , Cádmio/análise , Poluentes Ambientais/análise , Suínos , Agricultura , Animais , Disponibilidade Biológica , Cádmio/farmacocinética , Feminino , Fertilizantes/análise , Rim/química , Fígado/química , Masculino , Esterco , Poluentes do Solo/análise
11.
Analyst ; 126(1): 114-20, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11205500

RESUMO

Cadmium accumulates in proximal tubule cells causing a gradient of cadmium through the kidney, which is important to consider when sampling kidney tissue for cadmium analysis. In this study different sampling techniques of cattle and pig kidneys have been tested. Cadmium was determined by dry ashing-FAAS (detection limit 6.0 micrograms l-1, BCR (Community Bureau of Reference) No. 186 3.1 +/- 0.17 mg kg-1 (mean +/- s), laboratory quality sample (LQS) 495 +/- 17 micrograms kg-1) and microwave digestion-graphite furnace AAS (detection limit 0.24 microgram l-1, BCR No. 186 2.7 +/- 0.16 mg kg-1, LQS 444 +/- 14 micrograms kg-1) in homogenates, slices, and in cortex, intermediate and medulla zones of bovine and porcine kidneys. The bovine kidney lobulus cortex, intermediate zone, and medulla contained 70, 28 and 2% of the total cadmium content, and the relative weights of the zones were 53, 35 and 12%, respectively. The cadmium concentration in bovine cortex, intermediate zone and medulla was 1.37 +/- 7, 0.79 +/- 0.06 and 0.10 +/- 0.06 times the calculated homogenate concentration. Pig renal cortex, intermediate zone and medulla, contained 73, 26 and 0.5% respectively of the total cadmium content, and the relative weights were 63, 36 and 2.4%, respectively. The cadmium concentration in porcine cortex, intermediate zone and medulla was 1.14 +/- 0.05, 0.78 +/- 0.09 and 0.23 +/- 0.11 times the calculated homogenate concentration. Freezing of pig kidney caused a slight redistribution of cadmium from cortex to medulla. The results show that sampling technique is of greater importance for the determination of cadmium in bovine kidney than in pig kidney. A well described method for sampling of kidney is necessary to make it possible to compare results. To detect small differences in renal Cd levels between groups, as, e.g., in the case of biological monitoring of Cd exposure, sampling of the outer cortex is suggested as an optimal method.


Assuntos
Cádmio/análise , Contaminação de Alimentos , Rim/química , Análise de Variância , Animais , Bovinos , Humanos , Micro-Ondas , Manejo de Espécimes , Espectrofotometria Atômica , Estatísticas não Paramétricas , Suínos
12.
Arch Toxicol ; 75(9): 522-30, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11760812

RESUMO

Infants are exposed to higher levels of cadmium (Cd) from infant and follow-on formulas than from breast milk. We studied the bioavailability of 109CdCl2 from cows' milk formula, soy formula, wheat/oat/milk formula, wholemeal/milk formula and water in 11-day-old rat pups. The pups received a single oral dose of one diet labelled with 109Cd, 0.1 or 0.3 mg Cd/kg body weight. After 2 or 24 h or 4, 9 or 12 days the fractional retention of 109Cd in the whole body, in segments of rinsed small intestine and in tissue was measured in a gamma counter. Pups receiving 109Cd in water or cows' milk formula had the highest mean whole-body retention. It ranged from 67% of the dose in the water group to 52% in the wholemeal/milk formula group 4 days after dosing. The retention of 109Cd in the rinsed small intestine was significantly higher in the water group and the cows' milk formula group than in the cereal-based formula groups at 24 h and 4 days after dosing. It was still high in all groups on day 9, ranging from 26 to 11%. Initially most of the 109Cd was retained in the duodenum but by day 4 it had moved further down into the jejunum. In the liver, the highest and lowest retention on day 4 was 16%, and 3 per thousand of the dose in the water group and wholemeal/milk formula group, respectively. In the kidney, 109Cd was still increasing 12 days after exposure in all groups. Whole-body retention and tissue levels were higher than previously reported in adult animals. The lower bioavailability of 109Cd from the cereal-based formulas compared to water and cows milk formula on the longer survival times is most likely explained by Cd binding to dietary fibre and phytic acid in the cereal-based formulas reducing the intestinal binding and decreasing the bioavailability of Cd. The high retention of 109Cd in the small intestine, leading to a prolonged absorption period, emphasizes the importance of extending studies on neonatal Cd absorption over a long time period in order to detect for example, endpoints, accumulation of Cd in the kidney.


Assuntos
Cádmio/farmacocinética , Alimentos Infantis , Animais , Disponibilidade Biológica , Radioisótopos de Cádmio/análise , Feminino , Humanos , Lactente , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Distribuição Tecidual
13.
Phys Rev Lett ; 85(17): 3595-9, 2000 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-11030959

RESUMO

A measurement of direct photon production in 208Pb+208Pb collisions at 158A GeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons in central collisions is extracted as a function of transverse momentum in the interval 0.51.5 GeV/c. The result constitutes the first observation of direct photons in ultrarelativistic heavy-ion collisions. It could be significant for diagnosis of quark-gluon-plasma formation.

14.
Acta Crystallogr B ; 56 (Pt 2): 226-33, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10794276

RESUMO

A series of structures of trans-dichlorobis(triphenylarsine)platinum(II), recrystallized from four different solvents, have been characterized by X-ray crystallography and were shown to crystallize as different solvates (same metal complex, different crystallization solvents). Their geometric differences induced by packing and solvent molecules were analysed with half-normal probability plots and root-mean-square deviations. The recrystallization solvents used in the investigation were 1,1,1-trichloroethane, dichloromethane, 1,2-dichloroethane and benzene, and the following crystallization modes were obtained. From 1,1,1-trichloroethane the metal complex crystallizes without solvent as trans-[PtCl2(AsPh3)2] in P2(1)/n with Z = 2, a = 9.271 (2), b = 19.726 (4), c = 9.830 (2) A, beta = 111.83 (3)degrees, V = 1668.8 (6) A3, R = 0.0262, and from dichloromethane with two solvent molecules as trans-[PtC12(AsPh3)2].2CH2C12 in Pbca with Z= 4, a = 20.582 (4), b = 8.146 (2), c = 23.491 (5) A, V = 3938.5 (14) A3 and R = 0.0316. From dichloroethane it crystallizes with one solvent molecule as trans-[PtC12(AsPh3)2].C2H4C12 in P1 with Z = 1, a = 9.390 (2), b= 9.548 (2), c = 11.931 (2) A, alpha = 109.70 (3), beta = 108.26 (3), gamma = 98.77 (3) , V= 915.6 (3) A3, R = 0.0390, and from benzene with half a solvent molecule as trans- [PtC12(AsPh3)2].0.5C6H6 in P2(1)/n with Z = 4, a = 11.778 (2), b = 18.712 (4), c = 16.647 (3) A, beta = 104.78 (3) , V= 3547.3 (12) A3 and R = 0.0303. In all four compounds platinum(II) coordinates to triphenylarsine and chloride in a pseudo-square-planar trans configuration. The Pt-As distances are in the range 2.4104 (4)-2.3923 (4) A and the Pt-C distances are in the range 2.309 (2)-2.2839 (9) A. The solvents have a large influence on the packing, resulting in different space groups or different occupancies in the same space group. Half-normal probability plots show that the largest geometric differences, within the metal complex, are in the bond and torsion angles around the As-C bonds. Very similar torsion angles were observed around the Pt-As bond for all the structures, except for one AsPh3 ligand in the benzene solvate, which differs by about 10 from the others. The metal-donor bond distance varies by as much as 0.019 and 0.025 A (95% confidence interval) for Pt-As and Pt-C1, respectively. The variations are essentially caused by intermolecular interactions. Packing efficiency is expressed as the volume filled by each metal complex in the unit cell and is calculated by subtracting the sum of the solvent molecule volumes from the total volume of the unit cell and then dividing by Z. The efficiency is largest in the dichloroethane solvate and smallest in the non-solvated compound, with a difference of approximately 22 A3 per metal complex.

15.
Arch Toxicol ; 73(10-11): 519-27, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10663382

RESUMO

The purpose of the present investigation was to study the uptake of cadmium in mammary tissue, effects on milk secretion and composition, and lactational transport of cadmium to the sucklings. Cadmium exposure during lactation resulted in retention of cadmium in the mammary tissue in mice and rats. The uptake of cadmium in the mammary tissue was rapid, as shown in lactating mice by whole-body autoradiography 4 h after an intravenous injection of a tracer dose of (109)CdCl(2). Retention of cadmium in kidneys of suckling pups was observed in the autoradiograms at 7 days after exposure of the dams. Lactating rats were intravenously infused with (109)CdCl(2) in 0.9% saline via osmotic minipumps from day 3 to day 16 after parturition. The cadmium dose given was 0, 8.8, 62 and 300 microg Cd/kg body wt. per day. Plasma and milk were collected at day 10 and 16 after parturition. Plasma cadmium levels in dams increased from day 10 to day 16. Cadmium levels were higher in milk than in plasma, with milk/plasma ratios varying from 2 to 6. Zinc levels in milk were positively correlated to cadmium levels in milk (r(2)=0.26; P=0. 03). In milk, (109)Cd was distributed in fat (46-52%), casein fraction (40-46%), and whey fraction (6-8%). There was a high correlation between cadmium concentrations in pups' kidney and cadmium concentrations in dam's milk (r(2)=0.98; P < 0.001). Of the cadmium dose given to the dams <0.05% was retained in the litters on day 16 of lactation. No effects were observed due to cadmium exposure on body weight in pups or dams. Cadmium treatment did not cause any effect on the lactose or protein concentration in milk, the concentrations of DNA, RNA or the ratio RNA/DNA in the mammary gland. Histological evaluation of mammary tissue did not reveal any abnormalities at any dose level. (109)Cd was bound to metallothionein in mammary tissue. The fraction of radiolabelled cadmium bound to metallothionein increased in a dose-dependent manner in both the liver (88-98%) and mammary tissue (57-80%). The present results indicate a low transfer of cadmium to the suckling pup, which might be due to binding of cadmium to metallothionein in the mammary tissue. However, during the susceptible developmental period even a low cadmium exposure may be of concern.


Assuntos
Cádmio/farmacocinética , Glândulas Mamárias Animais/metabolismo , Leite Humano/metabolismo , Animais , Animais Recém-Nascidos/metabolismo , Autorradiografia , Cádmio/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Infusões Intravenosas , Rim/metabolismo , Lactação , Lactose/análise , Fígado/metabolismo , Glândulas Mamárias Animais/patologia , Metalotioneína/metabolismo , Camundongos , Gravidez , Ratos , Ratos Sprague-Dawley , Zinco/metabolismo
16.
Food Addit Contam ; 17(11): 937-43, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11271708

RESUMO

Bisphenol-A diglycidyl ether (BADGE) is used as an additive or starting agent in coatings for cans. The presence of hydrochloric acid in the organosol (PVC-based) lacquers results in formation of chlorohydroxy compounds of BADGE. These compounds, as well as BADGE itself, are potential migrants into the preserved food and are of toxicological concern. In the present investigation the presence of BADGE and the chlorohydroxy compounds (BADGE.HCl and BADGE.2HCl) in various kinds of canned foods from 30 brands have been determined by HPLC with fluorescence detection. BADGE was found in levels up to 5.1 mg/kg in the food and only in food from cans containing BADGE.HCl and BADGE.2HCl in the lacquers. BADGE was found both in fish in oil and in fish in tomato sauce, however, the highest amounts were found in the fatty foodstuffs. BADGE.HCl and BADGE.2HCl were found in concentrations up to 2.4 mg/kg and 8.3 mg/kg, respectively. Unlike BADGE, BADGE.2HCl was found in similar concentrations in fish in oil and in fish in tomato sauce. In aqueous and acidic foodstuffs BADGE readily hydrolyses into mono- and dihydrolysed products (BADGE.H2O and BADGE.2H2O). In this study BADGE.H2O was not found in any food sample, whereas BADGE.2H2O was found in levels up to 2.6 mg/kg. The Scientific Committee for Food (SCF) of the European Commission has proposed that a limit of restriction of 1 mg/kg food shall include BADGE itself and BADGE.H2O, BADGE.HCl, BADGE.2HCl and BADGE.HCL.H2O. The present results indicate that the migration of BADGE.HCl and BADGE.2HCl, compounds with almost no data on toxicity, implies a greater problem than BADGE.H2O and BADGE.2H2O.


Assuntos
Bis-Fenol A-Glicidil Metacrilato/análise , Contaminação de Alimentos , Embalagem de Alimentos , Conservação de Alimentos , Cromatografia Líquida de Alta Pressão , Humanos
17.
J Synchrotron Radiat ; 7(Pt 4): 203-8, 2000 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16609196

RESUMO

A new X-ray crystallographic beamline is operational at the MAX II synchrotron in Lund. The beamline has been in regular use since August 1998 and is used both for macro- and small molecule diffraction as well as powder diffraction experiments. The radiation source is a 1.8 T multipole wiggler. The beam is focused vertically by a bendable mirror and horizontally by an asymmetrically cut Si(111) monochromator. The wavelength range is 0.8-1.55 A with a measured flux at 1 A of more than 10(11) photons s(-1) in 0.3 mm x 0.3 mm at the sample position. The station is currently equipped with a Mar345 imaging plate, a Bruker Smart 1000 area CCD detector and a Huber imaging-plate Guinier camera. An ADSC 210 area CCD detector is planned to be installed during 2000.

18.
J AOAC Int ; 82(6): 1288-97, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10589479

RESUMO

Cadmium (Cd) concentrations in pig feeds (one control feed and one feed with reduced nitrogen content), straw, water, and pig kidney cortex were determined in 2 breeds of growing/finishing pigs (n = 96). The total Cd intake from feed was calculated. Feed mixtures and components, straw and kidney cortex samples, and certified reference samples were microwave-digested and analyzed by atomic absorption spectrometry with graphite furnace technique. Total Cd concentration in the control feed was 37.1 micrograms/kg wet weight (w.wt). The highest Cd levels were found in nonlocally produced feed components: vitamin-mineral mixture, lime, dicalcium phosphate, soybean meal, and rapeseed meal. These components contributed 70% of the Cd content in the feed. The main component, barley, which was locally produced, contributed 30% of the total Cd content in feed. The feed with reduced nitrogen content contained less soybean and rapeseed meal and a lower Cd level than the control feed. The Cd levels in kidney cortex varied from 38.0 to 105 micrograms/kg w.wt, with a mean level of 70.9 micrograms/kg. The levels differed between breeds and feeds, but not between gender. There was a significant correlation between Cd level in kidney cortex and age at slaughter, with an increase of 2.8 micrograms/kg w.wt in the kidney for each additional week of survival. The contribution of Cd from nonlocally produced feed components could have environmental effects through application of farmyard manure to local soils.


Assuntos
Ração Animal/análise , Cádmio/análise , Córtex Renal/química , Suínos , Animais , Brassica , Cádmio/administração & dosagem , Dieta , Feminino , Masculino , Solo/análise , Glycine max , Especificidade da Espécie , Espectrofotometria Atômica , Suínos/crescimento & desenvolvimento , Aumento de Peso
19.
Toxicology ; 137(3): 169-84, 1999 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-10522497

RESUMO

Inorganic mercury has previously been shown to be excreted to milk from plasma to a higher extent than methylmercury. Protein binding of mercury as methylmercury and inorganic mercury in whey and plasma from mouse and man was studied in order to get a better understanding of the transport of mercury into milk. Mice were administered a single i.v. dose of 0.25 mg Hg/kg body weight labelled with (CH3)203HgCl or 203HgCl2, resulting in 11 ng Hg/g milk and 38 ng Hg/g milk after 1 h, respectively. Milk and plasma from mice and man were also incubated with the respective radiolabelled compound (150 ng Hg/g milk or plasma). Casein, fat and whey fractions in milk from methylmercury treated mice were found to contain 11, 39 and 34%, respectively, and from inorganic mercury treated mice 31, 15 and 41%, respectively, of the total amount of mercury in milk. Serum albumin was a major mercury binding protein in whey and plasma from mice for both methylmercury and inorganic mercury, as demonstrated by FPLC gel filtration and anion-exchange chromatography and further characterised by SDS-PAGE for whey. In addition, anion-exchange chromatography indicated that inorganic mercury, but not methylmercury, in whey from mouse milk formed a dimer of serum albumin. The unbound fraction of mercury in whey and plasma from mice was very small (<0.7%), and somewhat higher in plasma and whey from man. It is concluded, that the unbound fraction in plasma cannot be a determining factor for the observed differences in milk excretion between the two mercury compounds. Instead, it is suggested that methylmercury and to some extent inorganic mercury are transferred from plasma into milk using albumin as a passive carrier.


Assuntos
Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Leite/metabolismo , Adulto , Animais , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Lactação , Mercúrio/sangue , Mercúrio/farmacocinética , Radioisótopos de Mercúrio , Compostos de Metilmercúrio/sangue , Compostos de Metilmercúrio/farmacocinética , Camundongos , Camundongos Endogâmicos , Proteínas do Leite/metabolismo , Ligação Proteica , Proteínas do Soro do Leite
20.
Toxicol Appl Pharmacol ; 154(2): 160-9, 1999 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9925800

RESUMO

The concentration of mercury in milk and the distribution pattern in the sucking pup was followed over time after administration of a single iv injection of 0.5 mg/kg body wt of 203Hg-labeled methylmercuric chloride or mercuric chloride to lactating mice on Day 10 of lactation. Mercury concentrations in milk of the dams and in whole body, blood, plasma, GI-tract, liver, kidneys, and brain of the offspring were followed up to 11 days after dosing (until lactational Day 21). Following the inorganic mercury dose to the dams, most of the mercury in milk was delivered to the pups during the first 24 h, but the maximum mercury concentration in plasma and tissues of pups was not reached until 7 days after dosing, indicating a prolonged absorption of inorganic mercury in the sucking pup. Pups of dams given methylmercury were exposed to a much lower and constant mercury concentration in milk. The estimated accumulated mercury dose via milk per pup of dams given methylmercury was less than half of that estimated after the inorganic mercury dose. When the accumulated dose via milk from methylmercury-exposed dams was compared to the amount of mercury in pup's carcass (whole body minus GI-tract including content), it was revealed that almost all mercury delivered via milk was absorbed, and that the suckling pups had a very low elimination of mercury until lactational Day 17. Lactational exposure following a maternal methylmercury or inorganic mercury dose resulted in almost similar mercury concentrations in liver, kidneys, and plasma of the suckling, but higher concentrations in brain (as most 14 times) and also twice as high mercury body burden in the methylmercury group. Thus, differences in kinetics indicate that lactational exposure of methylmercury is a greater hazard for the breast-fed infant than inorganic mercury.


Assuntos
Animais Recém-Nascidos/metabolismo , Lactação/fisiologia , Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Animais , Animais Lactentes , Feminino , Masculino , Mercúrio/farmacocinética , Radioisótopos de Mercúrio , Compostos de Metilmercúrio/sangue , Compostos de Metilmercúrio/farmacocinética , Camundongos , Camundongos Endogâmicos ICR , Leite/metabolismo , Distribuição Tecidual
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