1,720,981 research outputs found
Biomarker approach to evaluating the impact of scientific stations on the antarctic environment using Trematomus bernacchii as a bioindicator organism
No full textA biomonitoring study was performed to evaluate the human impact on two small coves adjacent to the Italian Scientific
Station at Terra Nova Bay in November 1995. The study used the fish species Trematomus bernacchii as a bioindicator organism
for a biomarker analysis based on porphyrin levels, and BPMO (Benzo(a)pyrene MonoOxygenase) and EROD (Ethoxyresorufin-
O-deethylase) activities. Porphyrin levels and EROD and BPMO activities were found to be generally low. In contrast to previous
years, no statistically significant difference was found between the potentially contaminated cove and the control cove after the
Italian expedition had been active nearby for a period of one month. This indicates a marked decrease in certain types of
contaminants such as organochlorines and trace metals, mainly due to improvements in waste disposal
Impact of marine contaminants of emerging concern on the cetacean transcriptome
No full textContaminants of emerging concern (CECs) are widely distributed in the environment, but their occurrence and potential toxicity are only now being evaluated. CECs are increasingly being detected in the waters and many act as endocrine disruptor compounds (EDCs), causing a variety of effects on health. The worldwide distributed perfluorooctanoic acid (PFOA) and bisphenol A (BPA) are CECs falling in the EDCs category.Skin samples from the bottlenose dolphin (Tursiops truncatus), a top predator that spends its entire life in the water and therefore subject to accumulation and magnification of contaminants, were collected to analyze the impact that environmentally relevant concentrations of CECs may have on global gene expression. We combined transcriptomic analysis and ex vivoassays using small skin slices cultured and treated for 24 h with PFOA or BPA or vehicle.RNA from dolphin biopsies was labeled and hybridized to a species-specific oligomicroarray. The skin transcriptome displayed changes related to contaminant exposure, potentially predictive about long-term effects on health, being the genes affected involved in immune modulation, response to stress, lipid homeostasis, and development. Within the genes differentially expressed in the transcriptome after CECs treatment, 4 were tested as potential gene markers of anthropogenic contaminants exposure on skin samples from wild cetaceans. RNA from 12 individuals, including the species Stenella coeruleoalba, T.truncatus, and Grampus griseuswere sampled in 3 areas (Adriatic, Ionian and Tyrrhenian seas). Three out of the 4 genes tested showed higher expression in the samples collected from the Adriatic sea.The transcriptomic signature of a dolphin skin could be relevant as classifier for a specific contaminant whilst giving information of the specific geographic location where the marine mammal spent its life, due to the different impact on gene expression exerted by different contamination levels
Levels of chemical contaminants and porphyrins in Caretta caretta from the Mediterranean Sea: preliminary results
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Biological threats and environmental pollutants, a lethal mixture for Mediterranean cetaceans?
No full textThe possible existence of any cause–effect relationships between the concentrations of organochlorines (OCs) and the presence of Morbillivirus and Toxoplasma gondii infections was investigated in both free-living and stranded specimens of Stenella coeruleoalba, Tursiops truncatus, Globicephala melas, Balaenoptera physalus and Physeter macrocephalus from the Mediterranean Sea. High blubber concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) were recorded in free-ranging G. melas. Tissue concentrations of PCBs and DDT in stranded T. truncatus(367 lipid weight (l.w.) and 143.7 mg/kg l.w., respectively) and S. coeruleoalba (139.9 l.w.; 92.9 mg/kg l.w.) were beyondthe PCB threshold value for the appearance of adverse effects in marine mammals. Evidence of T. gondii infection was molecularlydetected in three S. coeruleoalba and six T. truncatus.[...
Endocrine Disruptors in marine organisms: approaches and perspectives
No full textOrganic pollutants exhibiting endocrine disrupting activity (Endocrine Disruptors—EDs) are prevalent over a wide range in the aquatic ecosystems; most EDs are resistant to environmental degradation and are considered ubiquitous contaminants. The actual potency of EDs is low compared to that of natural hormones, but environmental concentrations may still be sufficiently high to produce detrimental biological effects.
Most information on the biological effects and mechanisms of action of EDs has been focused on vertebrates. Here we summarize recent progress in studies on selected aspects of endocrine disruption in marine organisms that are still poorly understood and that certainly deserve further research in the near future. This review, divided in four sections, focuses mainly on invertebrates (effects of EDs and mechanisms of action) and presents data on top predators (large pelagic fish and cetaceans), a group of vertebrates that are particularly at risk due to their position in the food chain. The first section deals with basic pathways of steroid biosynthesis and metabolism as a target for endocrine disruption in invertebrates. In the second section, data on the effects and alternative mechanisms of action of estrogenic compounds in mussel immunocytes are presented, addressing to the importance of investigating full range responses to estrogenic chemicals in ecologically relevant invertebrate species. In the third section we review the potential use of vitellogenin (Vtg)-like proteins as a biomarker of endocrine disruption in marine bivalve molluscs, used worldwide as sentinels in marine biomonitoring programmes. Finally, we summarize the results of a recent survey on ED accumulation and effects on marine fish and mammals, utilizing both classical biomarkers of endocrine disruption in vertebrates and non-lethal techniques, such as nondestructive biomarkers, indicating the toxicological risk for top predator species in the Mediterranean. Overall, the reviewed data underline the potential to identify specific types of responses to specific groups of chemicals such as EDs in order to develop suitable biomarkers that could be useful as diagnostic tools for endocrine disruption in marine invertebrates and vertebrates
Genotoxic effects of produced waters in mosquito fish (Gambusia affinis)
No full textThe aim of this study was to assess the potential genotoxic effects of produced water (PW) from an Italian on-shore oil plant. Produced water is a complex mixture containing residual hydrocarbons, trace elements, naturally occurring radioactive material and potentially toxic treatment chemicals such as biocides, dispersants, detergents and scale inhibitors used in oil production. The test organism, mosquito fish (Gambusia affinis), was divided into male and female groups and exposed for 8 days in the laboratory to 50% concentrations of different produced waters: PW before treatment and after settling treatment. The fish were also exposed to lower concentrations (10%) of the same PW for 30 days. DNA damage was evaluated in erythrocytes by single cell gel electrophoresis (Comet assay) and micronucleus test, while an oxidative stress biomarker, was assessed. Polycyclic aromatic hydrocarbons (PAH) metabolites in bile were also evaluated. A higher sensitivity in biomarker responses was found in females in comparison to males. An increase in DNA strand breaks was observed in both genders after 30 days exposure and a statistically significant increase of micronucleated cells was found in females after 8 days exposure. A positive correlation between presence of micronucleated cells and PAH metabolites in bile was also observed
Micronucleus test and comet assay for the detection of genotoxicity in Wood cells of Gambusia affinis exposed to produced waters
No full textPresenza di interferenti endocrini nel sangue di esemplari di Caretta caretta nel Mar Mediterraneo
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