Effects of exposure to Prestige-like heavy fuel oil and to perfluorooctane sulfonate on conventional biomarkers and target gene transcription in the thicklip grey mullet Chelon labrosus

Thicklip grey mullets Chelon labrosus inhabit coastal and estuarine areas where they can be chronically exposed to commonly released pollutants such as polycyclic aromatic hydrocarbons (PAHs) and perfluorinated compounds. These pollutants can also originate from accidental spills, such as the Prestige oil spill in 2002, which resulted in the release of a heavy fuel oil that affected coastal ecosystems in the Bay of Biscay. Peroxisome proliferation (PP), induced biotransformation metabolism, immunosuppression and endocrine disruption are some of the possible biological effects caused by such chemicals. With the aim of studying the effects of organic toxic chemicals on such biological processes at the transcriptional and at the cell/tissue level, juvenile mullets were exposed to the typical mammalian peroxisome proliferator perfluorooctane sulfonate (PFOS), and to fresh (F) and weathered (WF) Prestige-like heavy fuel oil for 2 and 16 days. First, fragments of genes relevant to biotransformation, immune/inflammatory and endocrine disruption processes were cloned using degenerate primers. Fuel oil elicited a significant PP response as proved by the transcriptional upregulation of palmitoyl-CoA oxidase (aox1), peroxisome proliferator activated receptor alpha (pparalpha) and retinoic X receptor, by the AOX1 activity induction and by the increased peroxisomal volume density. PFOS only elicited a significant induction of AOX1 activity at day 2 and of PPARalpha mRNA expression at day 16. All treatments significantly increased catalase mRNA expression at day 16 in liver and at day 2 in gill. Cyp1a transcription (liver and gill) and EROD activity were induced in fuel oil treated organisms. In the case of phase II metabolism only hepatic glutathione S-transferase mRNA was overexpressed in mullets exposed to WF for 16 days. Functionally, this response was reflected in a significant accumulation of bile PAH metabolites. WF treated fish accumulated mainly high molecular weight metabolites while F exposure resulted in accumulation of mainly low molecular ones. Fuel oil significantly regulated immune response related complement component C3 and hepcidin transcription followed by a significant regulation of inflammatory response related apolipoprotein-A1 and fatty acid binding protein mRNAs at day 16. These responses were accompanied by a significant hepatic inflammatory response with lymphocyte accumulations (IRLA) and accumulation of melanomacrophage centers (MMC). PFOS did not elicit any transcriptional response in the studied biotransformation and immune related genes, although histologically significant effects were recorded in IRLA and MMC. A significant reduction of lysosomal membrane stability was observed in all exposed animals. No endocrine disruption effects were observed in liver while brain aromatase mRNA was overexpressed after all treatments at day 2 and estrogen receptor alpha was downregulated under WF exposure at day 16. These results show new molecular and cellular biomarkers of exposure to organic chemicals and demonstrate that in mullets PP could be regulated through molecular mechanisms similar to those in rodents, although the typical mammalian peroxisome proliferator PFOS and heavy fuel oil follow divergent mechanisms of action.

Tissue- and cell-specific expression of metallothionein genes in cadmium- and copper-exposed mussels analyzed by in situ hybridization and RT–PCR

Metallothioneins (MTs) are metal-inducible proteins that can be used as biomarkers of metal exposure. In mussels two families of MT isoforms (MT10 and MT20) have been characterized. In this study, mussels (Mytilus galloprovincialis) were exposed to 200 ppb Cd and 40 ppb Cu for 2 and 9 days to characterize the tissue and isoform specificity of metal-induced MT expression. Non-radioactive in situ hybridization demonstrated that both MT isoforms were mainly transcribed in digestive tubule epithelial cells, especially in basophilic cells. Weaker MT expression was detected in non-ciliated duct cells, stomach and gill epithelial cells, haemocytes, adipogranular cells, spermatic follicles and oocytes. RT-PCR resulted in cloning of a novel M. galloprovincialis isoform homologous to recently cloned Mytilus edulis intron-less MT10B isoform. In gills, Cd only affected MT10 gene expression after 2 days of exposure while increases in MT protein levels occurred at day 9. In the digestive gland, a marked increase of both isoforms, but especially of MT20, was accompanied by increased levels of MT proteins and basophilic cell volume density (Vv(BAS)) after 2 and 9 days and of intralysosomal metal accumulation in digestive cells after 9 days. Conversely, although metal was accumulated in digestive cells lysosomes and the Vv(BAS) increased in Cu-exposed mussels, Cu exposure did not produce an increase of MT gene expression or MT protein levels. These data suggest that MTs are expressed in a tissue-, cell- and isoform-specific way in response to different metals.

Integrative assessment of the effects produced by Ag nanoparticles at different levels of biological complexity in Eisenia fetida maintained in two standard soils (OECD and LUFA 2.3)

There is a potential risk to increase the release of silver nanoparticles (Ag NPs) into the environment: For instance. in soils receiving sludge models estimate 0.007 mg Ag NPs kg^-1 that will annually increase due to sludge or sludge incineration residues land-disposal. Thus, the concern about the hazards of nanosilver to soils and soil invertebrates is growing. Studies performed up to now have been focused in traditional endpoints, used limit range concentrations and employed different soil types that differ in physico-chemical characteristics. Presently, effects of Ag NPs have been measured at different levels of biological complexity in Eisenia fetida, exposed for 3 and 14 d to high but sublethal (50 mg Ag NPs kg^-1) and close to modeled environmental concentrations (0.05 mg Ag NPs kg^-1). Since characteristics of the exposure matrix may limit the response of the organisms to these concentrations, experiments were carried out in OECD and LUFA soils, the most used standard soils. High concentrations of Ag NPs increased catalase activity and DNA damage in OECD soils after 14 d while in LUFA 2.3 soils produced earlier effects (weight loss, decrease in cell viability and increase in catalase activity at day 3). At day 14, LUFA 2.3 (low clay and organic matter-OM-) could have provoked starvation of earthworms, masking Ag NPs toxicity. The concentration close to modeled environmental concentrations produced effects uniquely in LUFA 2.3 soil. Accurate physico-chemical characteristics of the standard soils are crucial to assess the toxicity exerted by Ag NPs in E. fetida since low clay and OM contents can be considered toxicity enhancers.

Effects of PVP/PEI coated and uncoated silver NPs and PVP/PEI coating agent on three species of marine microalgae

In the last years, applications for silver nanoparticles (Ag NPs) continue to increase together with the concerns about their potential input and hazards in aquatic ecosystems, where microalgae are key organisms. The aim of the present study was to assess the relative sensitivity of three marine microalgae species with differences in cell wall composition/structure exposed to Poly N-vinyl-2-pirrolidone/Polyethyleneimine (PVP/PEI) coated 5nm Ag NPs and uncoated 47nm Ag NP. As limited attention has been paid to the role of coating agents in NP toxicity, the effect of PVP/PEI alone was also evaluated. After 72h in artificial seawater, 47nm Ag NPs formed around 1400nm size aggregates while PVP/PEI coated 5nm Ag NPs reached around 90nm. Ag⁺ release in seawater was around 3% for 47nm Ag NPs and 30% for PVP/PEI coated 5nm Ag NPs. PVP/PEI coated 5nm Ag NP aggregates entrapped the algal cells in a network of heteroaggregates, while uncoated 47nm Ag NPs interacted to a lesser extent with algae. The concentration of PVP/PEI coated 5nm Ag NPs that exerted the median effect (EC50) on algae growth pointed out differences in algae sensitivity: T. suecica was about 10 times more sensitive than I. galbana and P. tricornutum. Further, the coating agent alone was as toxic to algae as PVP/PEI coated 5nm Ag NPs, suggesting that presence of the coating agent was the main driver of toxicity of coated NPs. Uncoated 47nm Ag NPs instead, showed similar toxicity towards algae although P. tricornutum was slightly less sensitive than T. suecica and I. galbana, which agrees with the presence of a resistant silicified cell wall in the diatom. The present work demonstrates differences in sensitivity of three marine microalgae, possibly related to their cell surface and size characteristics.

Molecular cloning and measurement of telomerase reverse transcriptase (TERT) transcription patterns in tissues of European hake (Merluccius merluccius) and Atlantic cod (Gadus morhua) during aging

Telomerase is a reverse transcriptase ribonucleoprotein that maintains the ends of linear chromosomes. This enzyme plays a major role in cell processes like proliferation, differentiation and tumorigenesis, being associated with aging and survival of species. In this study, the gene coding for TERT (Telomerase Reverse Transcriptase) of two commercial fish species, European hake (Merluccius merluccius) and Atlantic cod (Gadus morhua), has been partially cloned. A fragment of 1581bp (hake) and 633bp (cod) showed high homology (identity 74%, query cover 99%, E-value=0) with known Perciformes TERT sequences. TERT transcription patterns were assessed by qRT-PCR in different tissues of hake (brain, ovary, testis, muscle, skin, gills, liver and kidney) and cod (brain, muscle and skin) of different sizes/ages in order to understand its role in the physiological aging of teleosts. TERT was found to be ubiquitously transcribed in all tissues and size/age groups studied in both species. Significantly higher relative transcription levels (p<0.05) were found with increasing size/age of M. merluccius in the kidney, muscle, skin and gonad, the latter exhibiting particularly high relative transcription levels. Male hakes showed higher TERT relative transcription levels in the brain, gonad and liver than females, although these differences were not statistically significant (p<0.05). In G. morhua, higher TERT relative transcription levels were recorded in the muscle and brain of fry and juvenile individuals. Therefore, TERT relative transcription pattern exhibited a higher telomerase demand in early developmental stages and also in mature stages, suggesting tissue renewal or regeneration processes as a conserved mechanism for maintaining long-term cell proliferation capacity and preventing senescence. Thus, it can be concluded that TERT relative transcription level was species and tissue specific and changed with the age of fishes.

Toxicology tailored low density oligonucleotide microarray for the thicklip grey mullets (Chelon labrosus): Biomarker gene transcription profile after caging in a polluted harbour

In aquatic organisms inhabiting polluted waters genes are activated to build an adaptive/compensatory defence against the possible effects of pollutants. Such responses can be used as biomarkers of exposure to chemical compounds, outlining the molecular mechanisms activated under specific pollution scenarios. With the aim of exploiting such approach in environmental health assessment, toxicologically relevant gene fragments were sequenced in the thicklip grey mullet (Chelon labrosus) and a toxicologically tailored low-density (160 genes) oligonucleotide microarray was customised. The tool was validated comparing organ/sex specific gene expression profiles and characterising responses under laboratory exposure to model chemicals. Finally, juvenile mullets were caged in a polluted harbour and hepatic gene expression profiles analysed after 5 and 21 days of deployment. Cages were deployed in the inner (IH) and outer (OH) Pasaia harbour, Bay of Biscay. Mussels (Mytilus galloprovincialis) were also caged as biological matrix for chemical bioaccumulation analysis and stress biomarkers measurements. Slightly higher concentrations of chemicals (metals, tributyltin, PAHs, phthalates) were quantified in IH than in OH, fish bile metabolites also revealing higher availability of PAHs in IH. Lysosome membrane stability in mussels was reduced, indicating stress condition in both sites. The developed microarray discriminated mullets showing distinctive expression profiles depending on site and deployment time. Genes related to immune and hypoxia responses were regulated comparing IH and OH at day 5. Phase I and II biotransformation genes, such as cyp2, cyp3 and ugt, were up-regulated in IH, together with the aryl hydrocarbon receptor 2 (ahr2) and the ahr repressor. Similarly, TBT-binding proteins and genes involved in lipid metabolism (pparγ, cyp7) were up-regulated with deployment time. Even if nowadays higher throughput approaches for gene expression analyses are available, the developed mullet tool constitutes a comprehensive tool to assess molecular responses of mullets exposed to pollutants, although it remains to be explored whether it can be applied to assess pollutant exposure in active pollution monitorings and in environmental health assessment.

[Fibrous hamartoma of the chest wall: apropos of a case]

Fibrous hamartoma of the child is one of the congenital fibromatosis. It is considered as an expansive, benign process, genuine of the settling site although changing in quantity, disposition and differentiation. The thoracic localization is very seldom found. Authors comment the most important features referring to this tumour.

Copolymerization of acenaphthylene with methacrylic monomers

The copolymerization of acenaphthylene with methylmethacrylate, ethylmethacrylate, butylmethacrylete, iso-butylmethacrylate and cyclohexylmethacrylate has been carried out in tetrahydrofuran at 323 K and the composition of the copolymers has been determined by size exclusion chromatography using a double RI-UV detector system. Several methods have been applied to obtain the reactivity ratios of the copolymerization process. The glass transition temperature of the copolymers has been obtained by DSC and the thermal stability has been studied by thermogravimetry. Analysis of the degradation volatile products reveals that copolymers degrade mainly by depolymerization.

Reutilization of thermostable polyester wastes by means of agglomeration with phenolic resins

We report on the possibility of obtaining organic polymeric matrixes allowing the development of new high performance fire-resistant products by recycling downsized thermostable waste materials. Phenolic resins have been used as binders for recycled waste. Furthermore, considering that reinforced plastic triturations have superior properties (chemical, mechanical, water resistance, etc.) to wood agglomerates, significant advantages over conventional materials are anticipated. In summary, we propose a viable solution to some of the known problems caused by the consumption of wood and to the needs of strengthened plastic processing engineering. Using resins as a binder, several fire-resistant prototypes were prepared from polyester waste, and their mechanical properties, thermal stability, and fire-resistant properties were analyzed.