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1.
Ecotoxicol Environ Saf ; 225: 112720, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34509163

RESUMO

The last remaining population of European sturgeon (Acipenser sturio) lives in the Gironde-Garonne-Dordogne (France) catchment (GGD). Captive young individuals are released into the GGD hydrosystem each year, as part of a restocking programme. This study aims to assess the health status of juveniles A. sturio to current conditions in the GGD hydrosystem, to evaluate their capacity to survive and grow in a moderately anthropized ecosystems. 3-month-old farmed sturgeons were exposed for one month in experimental conditions that mimic the environmental conditions in the Garonne and Dordogne rivers, followed by five months of depuration. After one month of exposure, fish exposed to Dordogne and Garonne waters bioaccumulated higher levels of metals and persistent organic pollutants, displayed a reduced hepato-somatic index, and had depleted levels of lipids and glycogen content in their liver, when compared with the Reference group. However, metabolic and swimming performance, as well as the costs of swimming were not impaired. After the 5 months depuration, a significant decrease of K was observed for all exposure conditions. HSI also decreased with time. The overall health status and adaptive capacity of juvenile A. sturio appeared to be maintained over the experimental 6 months' period. Juveniles of A. sturio seem to have the adaptive capacity to survive and grow in the GGD hydrosystem, after being released as part of a restocking programme.


Assuntos
Poluentes Orgânicos Persistentes , Rios , Animais , Ecossistema , Peixes , Humanos , Lactente , Metais
2.
Mol Ecol ; 25(1): 219-37, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-26562221

RESUMO

Measuring the effects of selection on the genome imposed by human-altered environment is currently a major goal in ecological genomics. Given the polygenic basis of most phenotypic traits, quantitative genetic theory predicts that selection is expected to cause subtle allelic changes among covarying loci rather than pronounced changes at few loci of large effects. The goal of this study was to test for the occurrence of polygenic selection in both North Atlantic eels (European Eel, Anguilla anguilla and American Eel, A. rostrata), using a method that searches for covariation among loci that would discriminate eels from 'control' vs. 'polluted' environments and be associated with specific contaminants acting as putative selective agents. RAD-seq libraries resulted in 23 659 and 14 755 filtered loci for the European and American Eels, respectively. A total of 142 and 141 covarying markers discriminating European and American Eels from 'control' vs. 'polluted' sampling localities were obtained using the Random Forest algorithm. Distance-based redundancy analyses (db-RDAs) were used to assess the relationships between these covarying markers and concentration of 34 contaminants measured for each individual eel. PCB153, 4'4'DDE and selenium were associated with covarying markers for both species, thus pointing to these contaminants as major selective agents in contaminated sites. Gene enrichment analyses suggested that sterol regulation plays an important role in the differential survival of eels in 'polluted' environment. This study illustrates the power of combining methods for detecting signals of polygenic selection and for associating variation of markers with putative selective agents in studies aiming at documenting the dynamics of selection at the genomic level and particularly so in human-altered environments.


Assuntos
Anguilla/genética , Genética Populacional , Metais/efeitos adversos , Seleção Genética , Poluentes Químicos da Água/efeitos adversos , Anguilla/classificação , Animais , Meio Ambiente , Genótipo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
3.
Chemosphere ; 139: 117-25, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26073702

RESUMO

The present investigation evaluates the recovery capabilities of Xenopus laevis following 12days of exposure to 30µg CdL(-1) and 1000µg ZnL(-1) alone or mixed, followed by a depuration phase in laboratory conditions. Focused endpoints, which were investigated at different times of depuration, are bioaccumulation of Cd and Zn, micronucleus induction, quantification of metallothioneins (MTs), and expression of genes involved in metal toxicity mechanisms. The results show that at the end of the contamination phase, there was higher metal bioaccumulation capability and MT synthesis in remaining tissues than in the liver. An increased expression of genes involved in detoxification and oxidative stress mechanisms was observed, suggesting an additive effect of both metals and a higher Zn regulation in the liver. During the depuration phase, the results show the recovery capability of Xenopus from 7days of depuration related to metamorphosis processes, which were observed at the end of the experiment. The results confirm the relevance of the amphibian model and the complementarities between a marker of genotoxicity, MT production, bioaccumulation and transcriptional analysis in the evaluation of the ecotoxicological impact. The results also highlight the reversible effects of Cd and Zn toxicity.


Assuntos
Cádmio/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Poluentes Químicos da Água/toxicidade , Xenopus laevis/crescimento & desenvolvimento , Zinco/toxicidade , Animais , Cádmio/metabolismo , Ecotoxicologia , Feminino , Expressão Gênica/efeitos dos fármacos , Inativação Metabólica , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Metalotioneína/metabolismo , Testes para Micronúcleos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/metabolismo , Xenopus laevis/genética , Xenopus laevis/metabolismo , Zinco/metabolismo
4.
Chemosphere ; 128: 125-33, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25698290

RESUMO

This study aimed to demonstrate the recovery potential of Danio rerio after Cd and Zn contaminations. Fish demonstrated high accumulation capacities of Cd with concentrations reaching 3716.4±578.6 µg Cd/kg FW in gills after 15 d of contamination. The 75-day decontamination failed to completely eliminate Cd (93.4% and 82.2% eliminated respectively in the gills of fish exposed to Cd and Cd/Zn) whereas Zn, poorly accumulated, was quickly depurated. The fast Cd depuration in the gills likely resulted from a metal transfer to the liver. MT response was clearly correlated to the Zn contamination, while genetic responses were more pronounced in case of Cd contamination. Cd induced over-expressions of genes involved against oxidative stress (sod, sodmt), and involved in detoxification mechanisms (mt1, mt2), mitochondrial mechanisms (cox1) and DNA repair (rad51 and gadd45). Zn binary contamination with Cd was demonstrated to provide protective effects on Cd-induced toxicity in D.rerio. Results highlighted that the genetic response was metal- and tissue-dependent. The brain and the muscles showed very few genetic responses, probably due to the low bioaccumulations measured in these tissues. Conversely, genes expressed in gills and liver of fish exposed to Cd were strongly affected (sod×3 and×12, mt1×11 and ×30 at T3 respectively in gills and liver). However, after 14-30 d of depuration, genes were no longer over expressed in response to Cd contamination in gills and liver of fish exposed to Cd and Cd/Zn conditions, suggesting an gene expression regulation of fish to the residual Cd contamination.


Assuntos
Cádmio/toxicidade , Regulação da Expressão Gênica/fisiologia , Inativação Metabólica/genética , Peixe-Zebra/metabolismo , Zinco/toxicidade , Animais , Brânquias/metabolismo , Fígado/metabolismo , Metalotioneína/metabolismo , Estresse Oxidativo/genética
5.
Environ Pollut ; 192: 74-82, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24892228

RESUMO

This study aimed to assess the recovery capacity of the freshwater bivalve Corbicula fluminea subjected to industrial metal discharges (Cd, Zn). After a 24-day exposure in a metal-contaminated river, bivalves were transferred and maintained in the laboratory for one year under metal-free conditions. Metal accumulation, metallothionein production and genetic expressions of genes involved in metal stress were studied. Results demonstrated the high persistence of Cd in tissues (only 73% eliminated after 365 days) whereas Zn was rapidly depurated. The Cd half-life was estimated around 240 days. Metallothioneins were strongly induced within the 28 first days of decontamination, then decreased by 45% after 365 days. The metal exposure of bivalves led to a significant gene induction. After 28 days, most of the genes were no longer overexpressed, suggesting that the bivalves may withstand small amounts of non-essential metals in their tissues without showing signs of detrimental effects on the tested genes.


Assuntos
Cádmio/toxicidade , Corbicula/fisiologia , Inativação Metabólica/fisiologia , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Animais , Bivalves/metabolismo , Cádmio/análise , Corbicula/metabolismo , Meia-Vida , Metalotioneína/metabolismo , Rios , Poluentes Químicos da Água/análise , Zinco/análise
6.
Chemosphere ; 108: 214-24, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24594487

RESUMO

The Riou-Mort watershed (southwest France) exhibits high metal contaminations (Cd and Zn) related to an important mining past. In this context, a remediation process has been implemented in 2007 to reduce the watershed contamination. The aim of this study was to assess the early effectiveness of the remediation process on the hydrosystem contamination state. A biomonitoring was realized over two years (2008-2010) with the filter-feeding bivalve Corbicula fluminea, exposed along a contamination gradient. Several biological parameters were monitored: (1) Cd and Zn bioaccumulation, (2) Metallothionein (MT) production as detoxification mechanism, (3) differential gene expression (cat, sod, gst, 12S, cox1, mt). The physicochemical data highlighted strong metal contamination persistence in the river water and failed to demonstrate a significant decrease of metal contamination during the 2-year monitoring. The bioaccumulation results confirmed the persistence of a water contamination despite remediation works, with maximum values measured downstream from the industrial site (Joany). The bioaccumulation increased in 2010, reaching 69.3±5.3 µg Cd g(-1) DW at Joany in July 2010, whereas it did not exceed 1.4±0.2 µg Cd g(-1) DW at the reference site throughout the biomonitoring. MT concentrations were closely related to the contamination gradient, especially at Joany, demonstrating their strong involvement in the detoxification processes. The mt gene induction was strongly correlated to the MT and metal concentrations. The gene inductions of cat, sod, gst and 12S were correlated to both the metal concentrations and the seasonal variations, especially temperatures. This suggests that environmental factors require serious consideration for the interpretation of bioaccumulation kinetics and thus for the assessment of the remediation effectiveness. Consequently, the whole results did not yet highlight strong beneficial effects of remediation work on the hydrosystem contamination state. First benefits of that process should be progressively felt, once the remediation achieved, and should grandly accelerate the decontamination process of the contaminated area.


Assuntos
Cádmio/análise , Corbicula/química , Monitoramento Ambiental , Recuperação e Remediação Ambiental , Poluentes Químicos da Água/análise , Zinco/análise , Animais , Corbicula/metabolismo , França , Água Doce/química , Metalotioneína/genética , Metalotioneína/metabolismo , Mineração , Espectrofotometria Atômica
7.
Sci Total Environ ; 437: 323-30, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22954653

RESUMO

Aiming at increasing the resolution of otolith tracers, we investigated the possibility to use Mn, Co, Zn, Rb, Cd, Sn, Ba, Sr, and Pb otolith composition to retrieve the movements of eels (Anguilla anguilla) in the lower Gironde watershed. Caging experiments were designed to validate the site specific otolith signatures. Individually identified eels were reared in cages in three locations along the estuarine and river gradient. Three trials were set up for successive periods of 3 months and 6 months. Water Mn, Co, Zn, Rb, Cd, Sn, Ba, Sr, and Pb concentrations were monitored. The eel otolith composition corresponding to the experimental period was measured with an ICPMS coupled with a femtosecond laser. Liver Cd, Zn and Pb concentrations were measured. For each caging experiments, we tested the influence of individual weight gain, caging site and trial on elemental otolith concentrations. Mn, Co, Zn, Rb, Cd, Sn, Ba, Sr, and Pb were detected in eel otolith above the detection limits. Otolith Sr and Ba concentrations significantly discriminated the caging sites for one trial. Individual weight gain did not have a significant influence on otolith elemental concentrations. Co, Rb, Cd, Sn, Zn, Sr and Ba otolith concentrations were significantly influenced by the trials. Water elemental composition was only partly reflected by otolith elemental composition. The results showed that otolith composition had a more integrative value than water composition. Complex elemental seasonal variations and individual eel incorporation potential complicated the interpretation of otolith composition. Liver and otolith Cd and Zn concentrations did not show a statistically significant correlation.


Assuntos
Anguilla/metabolismo , Exposição Ambiental , Metais Pesados/metabolismo , Membrana dos Otólitos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Bário/análise , Bário/metabolismo , Cádmio/análise , Cádmio/metabolismo , Cobalto/análise , Cobalto/metabolismo , Monitoramento Ambiental , Estuários , França , Chumbo/análise , Chumbo/metabolismo , Fígado/química , Manganês/análise , Manganês/metabolismo , Metais Pesados/análise , Membrana dos Otólitos/química , Rubídio/análise , Rubídio/metabolismo , Estrôncio/análise , Estrôncio/metabolismo , Estanho/análise , Estanho/metabolismo , Água/análise , Poluentes Químicos da Água/análise , Aumento de Peso , Zinco/análise , Zinco/metabolismo
8.
Ecotoxicol Environ Saf ; 74(6): 1573-7, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21531020

RESUMO

Ecotoxicological studies aim to assess the potential environmental risks of various products. This implies the use of various biological models and tests on live animals. In case of handling fish and mammals, ethical rules have to be respected. The use of anaesthesia is considered to be the best way to ensure animal welfare. Eugenol and electro-narcosis are among the most popular chemical and physical anaesthetics used in fisheries and by field biologists. In this study, the genetic and endocrine impacts of these anaesthetics were assessed in order to establish whether the use of such methods could skew the results of ecotoxicological studies. Twenty yellow European eels (Anguilla anguilla) were submitted to Eugenol (50mg/L) and electro-narcosis until they reached a level of deep anaesthesia, while 20 other eels were kept aware. Five anaesthetized and five unanaesthetized eels were sacrificed and analysed directly after treatment and after 1, 7 and 21 days of recovery. At the brain level, Eugenol triggered an increase in the transcription level of genes encoding proteins involved in oxidative stress responses (catalase expression 2.5-fold, mitochondrial superoxide dismutase expression 3-fold), probably due to a hypoxic event during anaesthesia. Later impacts were detected in muscles 21 days after anaesthesia (ATP synthase subunit 6 3-fold, NADH deshydrogenase subunit 5 4-fold and mitochondrial superoxide dismutase 3-fold increased) revealing oxidative stress from an accrued mitochondrial respiratory metabolism. Hormone dosages showed that the use of Eugenol reduced the release of plasma cortisol during anaesthesia. However, this impact seemed to be reversible within one day. In case of electro-narcosis, no significant variation in transcriptional levels could be detected between anaesthetized and unanaesthetized eels. Our results suggest that the use of Eugenol as an aesthetic in ecotoxicological studies measuring gene expression or plasma cortisol concentration is not appropriate, while electro-narcosis does not seem to have any impact, at least on the parameters taken into consideration in this study.


Assuntos
Anestésicos/toxicidade , Anguilla/fisiologia , Eletronarcose/efeitos adversos , Eugenol/toxicidade , Poluentes Químicos da Água/toxicidade , Anestésicos/metabolismo , Anguilla/genética , Anguilla/metabolismo , Animais , Catalase/metabolismo , Disruptores Endócrinos/toxicidade , Sistema Endócrino/efeitos dos fármacos , Sistema Endócrino/metabolismo , Expressão Gênica/efeitos dos fármacos , Hidrocortisona/sangue
9.
Mar Pollut Bull ; 60(8): 1307-18, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20394951

RESUMO

This study investigated some stress (metals, parasites) and response (immunity, metallothionein) factors in two cockle and two Manila clam populations. Data from eight seasons were averaged to obtain global baseline values. Stress/response characteristics of each population were compared to population health status that was determined through population dynamics parameters. Four different scenarios were discussed: (1) a lightly stressed cockle population with correct population health but with a risk of deterioration (hot spot); (2) a lightly stressed introduced cockle population threatened of extinction. In this case ecological factors were suspected; (3) a moderately stressed clam population with moderate adaptative response. The population was sustainable but the level of stress should not increase (hotspot); and (4) a stressed clam population and unfavourable ecological conditions preventing clam settlement. This monitoring highlighted that the discrepancy between population health and stress levels could be due to insufficient response by bivalves and/or by unfavourable ecological factors.


Assuntos
Bivalves/metabolismo , Monitoramento Ambiental/métodos , Estresse Fisiológico , Poluentes da Água/metabolismo , Animais , Bivalves/crescimento & desenvolvimento , Bivalves/parasitologia , Monitoramento Epidemiológico , Doenças Parasitárias em Animais/epidemiologia , Densidade Demográfica , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/veterinária , Poluentes da Água/toxicidade
10.
Environ Pollut ; 151(3): 532-42, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17629383

RESUMO

In a metal-polluted stream in the Riou Mort watershed in SW France, periphytic biofilm was analyzed for diatom cell densities and taxonomic composition, dry weight and metal bio-accumulation (cadmium and zinc). Periphytic diatom communities were affected by the metal but displayed induced tolerance, seen through structural impact (dominance of small, adnate species) as well as morphological abnormalities particularly in the genera Ulnaria and Fragilaria. Species assemblages were characterized by taxa known to occur in metal-polluted environments, and shifts in the community structure expressed seasonal patterns: high numbers of Eolimna minima, Nitzschia palea and Pinnularia parvulissima were recorded in Summer and Autumn, whereas the species Surirella brebissonii, Achnanthidium minutissimum, Navicula lanceolata and Surirella angusta were dominant in Winter and Spring. Commonly used indices such as the Shannon diversity index and Specific Pollution Sensitivity Index reflected the level of pollution and suggest seasonal periodicity, the lowest diversities being observed in Summer.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Metais Pesados/análise , Estações do Ano , Poluentes Químicos da Água/análise , Animais , Biofilmes , Cádmio/análise , Diatomáceas , Monitoramento Ambiental/instrumentação , Eucariotos , França , Movimentos da Água , Zinco/análise
11.
Environ Toxicol ; 22(4): 422-35, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17607733

RESUMO

The toxic and genotoxic potential of Cadmium (CdCl(2)) were evaluated by the micronucleus test (MNT) and comet assay (CA) using amphibian larvae (Xenopus laevis and Pleurodeles waltl). Acute toxicity results showed that Cd is toxic to Xenopus larvae exposed from 2 to 50 mg/L and to Pleurodeles from 5 to 50 mg/L, depending on the nature of the water (reconstituted water containing mineral salts or mineral water MW (Volvic)). The MNT results obtained in MW showed that Cd (2 mg/L) is genotoxic to Xenopus, whereas it was not genotoxic to Pleurodeles at all concentrations tested. The CA established that the genotoxicity of Cd to Xenopus and Pleurodeles larvae depends on the concentration, the exposure times, and the comet parameters (Tail DNA, ETM, OTM, and TL). The CA and MNT results were compared for their ability to detect genotoxic effects, considering the concentrations of Cd applied and the exposure time. The CA showed Cd to be genotoxic from the first day of exposure. In amphibians, the CA appears to be a sensitive and suitable method for detecting genotoxicity such as that caused by Cd.


Assuntos
Cádmio/toxicidade , Pleurodeles/embriologia , Animais , Cádmio/administração & dosagem , Ensaio Cometa , Larva/efeitos dos fármacos , Larva/genética , Testes para Micronúcleos , Pleurodeles/genética , Testes de Toxicidade Aguda , Xenopus laevis
12.
Parasitology ; 134(Pt 2): 237-45, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17032474

RESUMO

The aim of the present study was to analyse the relation between parasitism and subsequent metallothioneins (MT) in the case of metal contamination. Experimental exposure of parasitized and unparasitized cockles (Cerastoderma edule) to cadmium (Cd) was performed, with the cockle as first or second intermediate host of 2 digenean species. After 7 days of Cd exposure in microcosms, cockles infected as first intermediate host by Labratrema minimus exhibited metal concentrations in tissues double that in uninfected cockles. Jointly, MT concentrations of parasitized cockles were not modified in comparison with uninfected individuals in which concentrations were increased 4.3-fold compared with controls. In cockles experimentally infected as the second intermediate host by Himasthla elongata, cadmium concentrations significantly increased again in parasitized cockles compared with uninfected individuals in contaminated conditions. Simultaneously, MT concentrations in healthy cockles increased, whereas they significantly decreased in parasitized individuals. Therefore, the presence of digenean parasites in Cd-exposed cockles leads to a maintenance or a decrease in MT concentrations compared with healthy individuals, whereas Cd accumulation in tissues is significantly increased. These experiments indicate a significant alteration of the protective effect of metallothioneins towards metals which could consequently enhance cockle vulnerability. Moreover, these results highlight the limit of the use of MT as a biomarker of metal pollution in field monitoring if parasitism is not taken into account.


Assuntos
Cádmio/metabolismo , Cardiidae/metabolismo , Cardiidae/parasitologia , Metalotioneína/fisiologia , Trematódeos/patogenicidade , Animais , Biomarcadores , Cardiidae/química , Exposição Ambiental , Monitoramento Ambiental/métodos , Interações Hospedeiro-Parasita , Metalotioneína/metabolismo , Trematódeos/metabolismo , Poluentes Químicos da Água/metabolismo
13.
Biochimie ; 88(11): 1787-92, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16935407

RESUMO

Metallothioneins (MTs) are low-molecular-weight, cysteine-rich metal-binding proteins found in a wide variety of organisms including bacteria, fungi and all eukaryotic plant and animal species. MTs bind essential and non-essential heavy metals. In mammalian cells MT genes are highly inducible by many heavy metals including Zn, Cd, Hg, and Cu. Aquatic systems are contaminated by different pollutants, including metals, as a result of man's activities. Bivalve molluscs are known to accumulate high concentrations of heavy metals in their tissue and are widely used as bioindicators for pollution in marine and freshwater environments, with MTs frequently used as a valuable marker of metal contamination. We here describe the MT isoform gene expression patterns of marine and freshwater molluscs and fish species after Cd or Zn contamination. Contamination was carried out at a river site polluted by a zinc ore extraction plant or in the laboratory at low, environmentally relevant metal concentrations. A comparison for each species based on the accumulated MT protein levels often shows discrepancies between gene expression and protein level. In addition, several differences observed in the pattern of MT gene expression between mollusc and mammalian species enable us to discuss and challenge a model for the induction of MT gene expression.


Assuntos
Regulação da Expressão Gênica , Metalotioneína/genética , Animais , Cádmio/metabolismo , Peixes , Modelos Genéticos , Moluscos/metabolismo , Plantas/genética , Zinco/metabolismo
14.
Ann Rheum Dis ; 65(6): 826-8, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16699053

RESUMO

OBJECTIVE: To investigate the relation between temporal artery biopsy (TAB) length and diagnostic sensitivity for giant cell arteritis. METHODS: Histological TAB reports generated from four hospital pathology departments were reviewed for demographics, histological findings, and formalin fixed TAB lengths. A biopsy was considered positive for giant cell arteritis if there was a mononuclear cell infiltrate predominating at the media-intima junction or in the media. RESULTS: Among 1821 TAB reports reviewed, 287 (15.8%) were excluded because of missing data, sampling errors, or age < 50 years. Mean TAB length of the 1520 datasets finally analysed (67.2% women; mean (SD) age, 73.1 (10.0) years) was 1.33 (0.73) cm. Histological evidence of giant cell arteritis was found in 223 specimens (14.7%), among which 164 (73.5%) contained giant cells. Statistical analyses, including piecewise logistic regression, identified 0.5 cm as the TAB length change point for diagnostic sensitivity. Compared with TAB length of < 0.5 cm, the respective odds ratios for positive TAB without and with multinucleated giant cells in samples > or = 0.5 cm long were 5.7 (95% confidence interval, 1.4 to 23.6) and 4.0 (0.97 to 16.5). CONCLUSIONS: A fixed TAB length of at least 0.5 cm could be sufficient to make a histological diagnosis of giant cell arteritis.


Assuntos
Arterite de Células Gigantes/patologia , Artérias Temporais/patologia , Idoso , Biópsia/métodos , Feminino , Humanos , Modelos Logísticos , Masculino , Serviço Hospitalar de Patologia , Estudos Retrospectivos , Reumatologia , Sensibilidade e Especificidade
15.
Aquat Toxicol ; 78(2): 157-66, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16616381

RESUMO

The present investigation evaluates the toxic potential of Cd in larvae of the frog Xenopus laevis after 12 days of exposure to environmentally relevant contamination levels, close to those measured in the river Lot (France). Several genotoxic and detoxification mechanisms were analyzed in the larvae: clastogenic and/or aneugenic effects in the circulating blood by micronucleus (MN) induction, metallothionein (MT) production in whole larvae, gene analyses and Cd content in the liver and also in the whole larvae. The results show: (i) micronucleus induction at environmental levels of Cd contamination (2, 10, 30 microgL(-1)); (ii) an increased and concentration-dependent quantity of MT in the whole organism after contamination with 10 and 30 microgCdL(-1) (a three- and six-fold increase, respectively) although no significant difference was observed after contamination with 2 microgCdL(-1); (iii) Cd uptake by the whole organism and by the liver as a response to Cd exposure conditions; (4) up-regulation of the genes involved in detoxification processes and response to oxidative stress, while genes involved in DNA repair and apoptosis were repressed. The results confirm the relevance of the amphibian model and highlight the complementarity between a marker of genotoxicity, MT production, bioaccumulation and genetic analysis in the evaluation of the ecotoxicological impact.


Assuntos
Cádmio/toxicidade , Exposição Ambiental , Expressão Gênica/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Xenopus laevis/fisiologia , Animais , Cádmio/análise , Cádmio/farmacocinética , Primers do DNA/química , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Metalotioneína/análise , Testes para Micronúcleos/veterinária , Testes de Mutagenicidade/veterinária , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Regulação para Cima , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinética , Xenopus laevis/genética
16.
Sci Total Environ ; 337(1-3): 265-80, 2005 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-15626396

RESUMO

A 15-month experiment combining a geochemical survey of Cd, Cu, Zn and Hg with a bioaccumulation study for three filter-feeding bivalve species (oysters, Crassostrea gigas; cockles, Cerastoderma edule; and clams, Ruditapes philippinarum) was conducted in a breeding basin of the Nord Medoc salt marshes connected to the Gironde estuary, which is affected by historic polymetallic pollution. Regular manual surface measurements of temperature, salinity, pH and dissolved O(2) concentration and hourly multiprobe in situ measurements throughout several periods for 6-8 weeks were performed. The geochemical behavior of metals in water, suspended particulate matter and sediment and their ecotoxicological impact on the three bivalve species were evaluated by in situ exposure of juvenile oysters (water column) and adult cockles and clams (sediment surface). The physico-chemical parameters reflected seasonal variations and basin management. A distinct daily periodicity (except salinity) indicated intense photosynthesis and respiration. In summer, low dissolved O(2) saturations ( approximately 40-50%) occurred in the early morning at 30 cm above the sediment, whereas in depressions, the water column near the sediment surface was suboxic. Cadmium, Zn and Cu concentrations in suspended particulate matter exceeded typical estuarine values and were much higher than the homogeneously distributed concentrations in different depth ranges of the basin sediment. Particles collected in sediment traps showed intermediate metal concentrations close to sediment values. These results suggest trace metal recycling due to reductive dissolution under suboxic conditions at the sediment surface resulting in trace metal release to the water column and adsorption onto suspended particles. Dissolved Cd, Zn and Hg concentrations (e.g. 13-136 ng l(-1); 0.3-25.1 microg l(-1) and 0.5-2.0 ng l(-1), respectively) in the basin corresponded to the concentration range typically observed in the Gironde estuary, except for some maximum values attributed to metal recycling. In contrast, dissolved Cu concentrations (1.08-6.08 microg l(-1)) were mostly higher than typical estuarine values, probably due to recycled Cu complexation by dissolved organic matter. Growth, bioaccumulation rates and kinetics in the whole soft body of the bivalves were analyzed every 40 days. Although Cd bioaccumulation of oysters was lower in the basin than in the estuary during the same period (27,000 ng g(-1), dry weight and 40,000 ng g(-1), respectively) these values are largely above the new human consumption safety level (5000 ng g(-1), dw; European Community, 2002). For cockles and clams, Cd bioaccumulation was lower, reaching 1400 ng g(-1) and 950 ng g(-1), respectively. Similar results were obtained for Zn and Cu suggesting physiological differences between the species and/or differences in the exposure of the organisms due to physico-chemical conditions and metal distribution between dissolved and particulate phases. In contrast, Hg bioaccumulation was highest for cockles reaching bioconcentration factors of approximately 200,000, which even exceeded that of Cd in oysters (50,000) for the same exposition period. Nevertheless, Hg concentrations remained relatively low in the three bivalve species.


Assuntos
Bivalves/metabolismo , Metais Pesados/metabolismo , Moluscos/metabolismo , Ostreidae/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Aquicultura , Bivalves/química , Bivalves/crescimento & desenvolvimento , Monitoramento Ambiental , França , Sedimentos Geológicos/análise , Metais Pesados/análise , Moluscos/química , Moluscos/crescimento & desenvolvimento , Ostreidae/química , Ostreidae/crescimento & desenvolvimento , Água do Mar , Fatores de Tempo , Poluentes Químicos da Água/análise
17.
Aquat Toxicol ; 67(4): 347-57, 2004 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-15084411

RESUMO

Multixenobiotic resistance mechanisms (MXR) related to the mammalian P-glycoprotein multidrug transporter protein (P-gp) are known to occur in several marine invertebrates. In the present work, we report on the induction of an MXR protein by various heavy metals in the gills of the freshwater clam Corbicula fluminea. The evaluation of the MXR protein level was assessed by Western blot using a specific monoclonal antibody raised against the human P-gp (C219). A field transplantation experiment, where clams were caged in a gradient relative to an industrial site, demonstrated a positive relationship between MXR levels and (a) metal pollution (Cd and Zn) in the environment and (b) metal bioaccumulation in the gills. To establish this correlative relationship, clams were exposed to different levels of cadmium (15-60 microg l(-1)) for up to 15 days in a controlled laboratory experiment. MXR protein levels increased in time for all treatments (including the control). However, the highest levels of MXR protein titer were expressed in clams that had been exposed to the lowest dose of cadmium. The causes for this observed inverse relationship between the exposure dose and the MXR induction is discussed. MXR protein titer was also shown to be induced by other heavy metals (zinc, inorganic mercury, and copper).


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Bivalves/metabolismo , Resistência a Múltiplos Medicamentos/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bivalves/fisiologia , Western Blotting , Relação Dose-Resposta a Droga , França , Brânquias/metabolismo , Metais Pesados/farmacocinética , Poluentes Químicos da Água/farmacocinética
18.
Presse Med ; 32(11): 498-500, 2003 Mar 22.
Artigo em Francês | MEDLINE | ID: mdl-12733388

RESUMO

INTRODUCTION: The diagnostic approach when confronted with a pseudo-tumoral lesion and fever is difficult since it evokes an infectious, rheumatismal inflammatory or even systemic disease. OBSERVATION: A 39 year-old Vietnamese man was hospitalised for polyarthralgia if the arm and fever (39 degrees C). He was treated with non-steroidal anti-inflammatories, which were only partially effective. Biological examinations revealed a severe inflammatory syndrome and cytolysis three-fold higher than normal. Since the infectious, rheumatismal and immunological explorations were negative and in view of the appearance of a pseudo-tumoral inflammatory lesion of the left arm concomitant to infiltration of the underlying muscle revealed on MRI, a muscle biopsy was performed showing eosinophilic fasciitis. Diagnosis of Shulman's syndrome was made and the affection rapidly improved with corticosteroids. COMMENTS: The presentation of our patient was atypical for several reasons: his Vietnamese origin, the initial fever peak at 39 degrees C, the unilateral involvement, the severe inflammatory syndrome, the initial absence of hypereosinophilia, the visceral involvement and notably myositis are all uncommon in Shulman's syndrome. Hence, it is important to rule out its differential diagnosis from local edematous scleroderma, which does not share the same prognosis.


Assuntos
Braço , Artralgia/etiologia , Eosinofilia/diagnóstico , Fasciite/diagnóstico , Febre de Causa Desconhecida/etiologia , Granuloma de Células Plasmáticas/diagnóstico , Adulto , Braço/patologia , Biópsia , Diagnóstico Diferencial , Eosinofilia/patologia , Fáscia/patologia , Fasciite/patologia , Granuloma de Células Plasmáticas/patologia , Humanos , Angiografia por Ressonância Magnética , Masculino , Músculo Esquelético/patologia , Síndrome
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