Acetylcholinesterase activity in muscle tissue of Norway lobster Nephrops norvegicus: Importance of body size, season, sex and naturally occurring metals

The aim of the present study was to determine the levels of acetylcholinesterase (AChE) activity in the tail muscle tissue of wild populations of Nephrops norvegicus from the Northern Adriatic, and correlate it to body size, seasons, sex and the content of mercury, arsenic, cadmium, lead and copper. The animals of both sexes were collected in spring and autumn from two relatively distant fishing grounds. A marked variability of muscle AChE activity was found (0.49 to 11.22 nmol/min/mg prot.), displaying the opposite seasonal trend between two sampling sites. Small, but significant negative correlation has been found between AChE activity and carapace length (rs = - 0.35, p < 0.05). Data reported here provide an essential baseline for future studies of neurotoxicity in crustaceans. The study highlights the necessity for continuous monitoring of potentially toxic metals in edible marine species to avoid possible repercussions of seafood consumption on human health.

Barcoding (COI) Sea Cucumber Holothuria mammata Distribution Analysis: Adriatic Rare or Common Species?

The overexploitation of the western Pacific Ocean has expanded the sea cucumber fishery into new regions to supply the Asian market. In 2013, sea cucumbers were removed from the Croatian marine protected species list, and commercial fishery took place for a short period (2017-2018) in the Eastern Adriatic Sea. However, holothuroid species are difficult to distinguish. Holothuria mammata is a species that has rarely been reported in this region and strongly resembles the common species Holothuria tubulosa. This is the first study to assess the genetic diversity of sea cucumbers in the Adriatic Sea using genetic barcoding of the mitochondrial gene cytochrome c oxidase subunit 1 (COI). Specimens for barcoding were collected from the northern and central Adriatic, along with a specimen that had been previously identified as H. sp. cf. mammata based on its morphological characteristics. While genetic analyses showed identified this specimen as H. tubulosa, 30% of the collected specimens were genetically identified as H. mammata. These results call into question the historically accepted sea cucumber assemblage in the Adriatic Sea, which regarded H. mammata as a rare species and generally disregarded its presence in large census studies. Such species distribution data are extremely important in developing and monitoring a sustainable fishery.

Prevalence of reaching target low-density lipoprotein cholesterol (LDL-C) in very high-risk patients using high intensity lipid-modifying therapy

Background

Hyperlipidemia is an important risk factor for developing cardiovascular disease. Lowering LDL-C reduces the risk for coronary heart disease: the longer LDL-C remains low, the better. We studied the effect of implementing a guideline based, stepwise approach of lipid-modifying therapy to achieve target LDL-C levels in very high-risk patients in daily clinical practice in the Netherlands.

Methods

Nine hundred and ninety-nine (999) patients with a type I (N)STEMI and a history of Atherosclerotic Cardiovascular Disease and/or Diabetes mellitus II were included. Patients with LDL-C &gt;1.8 mmol/L were treated with high-intensity statin (HIST) monotherapy. If target LDL-C level was not reached, first ezetimibe and subsequently a PCSK9i was added. The primary objective was to assess the prevalence of reaching LDL-C ≤1.8mmol/L with HIST and/or ezetimibe.

Results

Nine hundred and thirty-nine (939) patients were treated with HIST and/or ezetimibe, of whom 89% reached LDL-C ≤1.8 mmol/L. Yet thirty four (34) of the 40 patients (85%) who received additional treatment with PCSK9i, reached the target LDL. After treatment with HIST, HIST plus ezetimibe, and HIST plus ezetimibe and PCSK9i in the per protocol population the cumulative prevalence of reaching target LDL-C was 71%, 89% and 99% respectively.

Conclusion

Using an ESC guideline-based flowchart with stepwise intensification of lipid-lowering drugs, using HIST and/or ezetimibe, 89% of the very high-risk patients reached an LDL-C ≤1.8 mmol/L in 57 days ± 38 (mean ± SD). Including patients in whom additional PCSK9i was started, success rate of meeting target LDL-C rose to 99%.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi-Aventis Netherlands B.V.

Physico-Chemical and Ecotoxicological Evaluation of Marine Sediments Contamination: A Case Study of Rovinj Coastal Area, NE Adriatic Sea, Croatia

Comprehensive spatial and temporal data on sediment quality in the Adriatic Sea are lacking. Therefore, prior to planned anthropogenic interventions in the local marine environment, such as deepening of the Rovinj harbour, the results of physicochemical and ecotoxicological analyses of five local coastal sediments were compared with regional averages and SQGs of neighbouring countries. Analyses of sediment grain size, content of metals and heavy metals, PAHs and PCBs were performed according to standard protocols. Sediment quality was classified according to French legislation (N1 and N2 level) and sediment guidelines. The phytotoxicity of the eluates was studied by flax seed germination tests. The logistic regression models P_max and P_avg were used to estimate the probability of toxic effects. Except for the open sea (S5), all other sediments had concentrations slightly higher than the N1 for some metals (Cu, Ni, Hg, Cr) or ΣPAHs, while the Rovinj harbour (S1) reached the N2 value for mercury. The phytotoxicity assay with sediment eluates showed inhibition of germination, root length and root biomass production, with an average phytotoxicity index (PI) ranging from 6.06% to 42.00%. Significant correlations of P_avg and P_max values with phytotoxicity and other specific parameters were found. In general, according to the applied SQGs, there are no potential ecological impacts on the marine environment at any of the investigated sites, with the exception of site S1.

Simultaneous Influence of Gradients in Natural Organic Matter and Abiotic Parameters on the Behavior of Silver Nanoparticles in the Transition Zone from Freshwater to Saltwater Environments

As nanoparticles have been found to cause a range of harmful impacts in biota, understanding processes and transformations which may stabilize and increase their persistence time in the environment are of great importance. As nanoparticles carried in riverine or wastewaters will eventually reach estuaries, understanding their behavior and transport potential in this transition zone from fresh to marine waters is essential, particularly as estuaries are sensitive ecological zones, oftentimes encompassing ornithologically important areas. In this direction, we report on the influence of combined gradients of riverine and marine natural organic matter (NOM) on the temporal stability of biocorona-encapsulated silver nanoparticles in terms of ion release kinetics. In parallel, salinity, pH and oxygen saturation were simultaneously varied to create a model to mimic the complex estuarine environment. While humic acid (HA) and alginate (Alg) disrupted the stabilizing ability of the nanoparticle protein corona to a greater and lesser degree, respectively, they slowed the rate of ion release in freshwater at pH 6.6 and in saltwater at pH 8, respectively, while oxygen saturation was also found to be an important factor. Thus, as the type of NOM changes with pH along a salinity gradient in an estuary, conditions required to increase the persistence time of nanoparticles are serendipitously met, with greater colloidal stability achieved in cases where there is more rapid replacement of HA with Alg. Despite the strong gradients in ionic strength, pH and oxygen saturation, the protein corona was not sufficiently disrupted at the nanoparticle surface to be substituted by NOM indicating the greater adsorption energy of the protein's hydrophobic domains. Ultimately, it is the specific NOM profile of individual estuaries that may provide the best indicator for predicting the stability and persistence of silver nanoparticles as they transition from fresh to salt water environments.

Parallel pattern of differentiation at a genomic island shared between clinal and mosaic hybrid zones in a complex of cryptic seahorse lineages

Diverging semi-isolated lineages either meet in narrow clinal hybrid zones, or have a mosaic distribution associated with environmental variation. Intrinsic reproductive isolation is often emphasized in the former and local adaptation in the latter, although both reduce gene flow between groups. Rarely are these two patterns of spatial distribution reported in the same study system. Here, we report that the long-snouted seahorse Hippocampus guttulatus is subdivided into discrete panmictic entities by both types of hybrid zones. Along the European Atlantic coasts, a northern and a southern lineage meet in the southwest of France where they coexist in sympatry-i.e., in the same geographical zone-with little hybridization. In the Mediterranean Sea, two lineages have a mosaic distribution, associated with lagoon-like and marine habitats. A fifth lineage was identified in the Black Sea. Genetic homogeneity over large spatial scales contrasts with isolation maintained in sympatry or close parapatry at a fine scale. A high variation in locus-specific introgression rates provides additional evidence that partial reproductive isolation must be maintaining the divergence. We find that fixed differences between lagoon and marine populations in the Mediterranean Sea belong to the most differentiated SNPs between the two Atlantic lineages, against the genome-wide pattern of structure that mostly follow geography. These parallel outlier SNPs cluster on a single chromosome-wide island of differentiation. Since Atlantic lineages do not map to lagoon-sea habitat variation, genetic parallelism at the genomic island suggests a shared genetic barrier contributes to reproductive isolation in contrasting contexts-i.e., spatial versus ecological. We discuss how a genomic hotspot of parallel differentiation could have evolved and become associated both with space and with a patchy environment in a single study system.

The hidden side of a major marine biogeographic boundary: a wide mosaic hybrid zone at the Atlantic-Mediterranean divide reveals the complex interaction between natural and genetic barriers in mussels

The Almeria-Oran Front (AOF) is a recognised hotspot of genetic differentiation in the sea, with genetic discontinuities reported in more than 50 species. The AOF is a barrier to dispersal and an ecological boundary; both can determine the position of these genetic breaks. However, the maintenance of genetic differentiation is likely reinforced by genetic barriers. A general drawback of previous studies is an insufficient density of sampling sites at the transition zone, with a conspicuous lack of samples from the southern coastline. We analysed the fine-scale genetic structure in the mussel Mytilus galloprovincialis using a few ancestry-informative loci previously identified from genome scans. We discovered a 600-km-wide mosaic hybrid zone eastward of the AOF along the Algerian coasts. This mosaic zone provides a new twist to our understanding of the Atlantic-Mediterranean transition because it demonstrates that the two lineages can live in sympatry with ample opportunities to interbreed in a large area, but they hardly do so. This implies that some form of reproductive isolation must exist to maintain the two genetic backgrounds locally cohesive. The mosaic zone ends with an abrupt genetic shift at a barrier to dispersal in the Gulf of Bejaia, Eastern Algeria. Simulations of endogenous or exogenous selection in models that account for the geography and hydrodynamic features of the region support the hypothesis that sister hybrid zones could have been differentially trapped at two alternative barriers to dispersal and/or environmental boundaries, at Almeria in the north and Bejaia in the south. A preponderantly unidirectional north-south gene flow next to the AOF can also maintain a patch of intrinsically maintained genetic background in the south and the mosaic structure, even in the absence of local adaptation. Our results concur with the coupling hypothesis that suggests that natural barriers can explain the position of genetic breaks, while their maintenance depends on genetic barriers.

Environmental status of the NE Adriatic Sea, Istria, Croatia: Insights from mussel Mytilus galloprovincialis condition indices, stable isotopes and metal(loid)s

The environmental status of the marine environment in the NE Adriatic Sea was assessed, using as a bioindicator species the Mediterranean mussel Mytilus galloprovincialis Lamarck, 1819. Samples were collected seasonally from mariculture sites and from major Istrian ports between the years 2010 and 2013. The condition indices of mussels ranged from 13.3 to 20.9% at mariculture sites and from 14.3 to 23.3% at port locations. The seasonally δ¹³C_DIC values of seawater varied between -10.9 to 0.7‰. Pollution by sewage sludge (based on δ¹⁵N values) was confirmed only in two ports. Tissue concentrations of Mn, Co, Ni, Cu, Zn, Se, Cd, and Pb were significantly higher in the tissue of the mussels collected from the ports (polluted sites). Arsenobetaine was the major As compound present in the samples and there was no significant difference in the levels of total As in mussel tissues from mariculture and port sites.

Conservation physiology of marine fishes: state of the art and prospects for policy

The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes is the limited knowledge base; international collaboration is needed to study the environmental physiology of a wider range of species. Multifactorial field and laboratory studies on biomarkers hold promise to relate ecophysiology directly to habitat quality and population status. The 'Fry paradigm' could have broad applications for conservation physiology research if it provides a universal mechanism to link physiological function with ecological performance and population dynamics of fishes, through effects of abiotic conditions on aerobic metabolic scope. The available data indicate, however, that the paradigm is not universal, so further research is required on a wide diversity of species. Fish physiologists should interact closely with researchers developing ecological models, in order to investigate how integrating physiological information improves confidence in projecting effects of global change; for example, with mechanistic models that define habitat suitability based upon potential for aerobic scope or outputs of a dynamic energy budget. One major challenge to upscaling from physiology of individuals to the level of species and communities is incorporating intraspecific variation, which could be a crucial component of species' resilience to global change. Understanding what fishes do in the wild is also a challenge, but techniques of biotelemetry and biologging are providing novel information towards effective conservation. Overall, fish physiologists must strive to render research outputs more applicable to management and decision-making. There are various potential avenues for information flow, in the shorter term directly through biomarker studies and in the longer term by collaborating with modellers and fishery biologists.

Purification and partial characterization of a lectin protein complex, the clathrilectin, from the calcareous sponge Clathrina clathrus

Carbohydrate-binding proteins were purified from the marine calcareous sponge Clathrina clathrus via affinity chromatography on lactose and N-acetyl glucosamine-agarose resins. Proteomic analysis of acrylamide gel separated protein subunits obtained in reducing conditions pointed out several candidates for lectins. Based on amino-acid sequence similarity, two peptides displayed homology with the jack bean lectin Concanavalin A, including a conserved domain shared by proteins in the L-type lectin superfamily. An N-acetyl glucosamine - binding protein complex, named clathrilectin, was further purified via gel filtration chromatography, bioguided with a diagnostic rabbit erythrocyte haemagglutination assay, and its activity was found to be calcium dependent. Clathrilectin, a protein complex of 3200kDa estimated by gel filtration, is composed of monomers with apparent molecular masses of 208 and 180kDa estimated on 10% SDS-PAGE. Nine internal peptides were identified using proteomic analyses, and compared to protein libraries from the demosponge Amphimedon queenslandica and a calcareous sponge Sycon sp. from the Adriatic Sea. The clathrilectin is the first lectin isolated from a calcareous sponge and displays homologies with predicted sponge proteins potentially involved in cell aggregation and interaction with bacteria.

Exploring Actinobacteria assemblages in coastal marine sediments under contrasted Human influences in the West Istria Sea, Croatia

The exploration of marine Actinobacteria has as major challenge to answer basic questions of microbial ecology that, in turn, will provide useful information to exploit Actinobacteria metabolisms in biotechnological processes. The ecological functions performed by Actinobacteria in marine sediments are still unclear and belongs to the most burning basic questions. The comparison of Actinobacteria communities inhabiting marine sediments that are under the influence of different contamination types will provide valuable information in the adaptation capacities of Actinobacteria to colonize specific ecological niche. In the present study, the characterization of different Actinobacteria assemblages according to contamination type revealed the ecological importance of Actinobacteria for maintaining both general biogeochemical functions through a "core" Actinobacteria community and specific roles associated with the presence of contaminants. Indeed, the results allowed to distinguish Actinobacteria genera and species operational taxonomic units (OTUs) able to cope with the presence of either (i) As, (ii) metals Ni, Fe, V, Cr, and Mn, or (iii) polycyclic aromatic hydrocarbons (PAHs) and toxic metals (Hg, Cd, Cu, Pb, and Zn). Such observations highlighted the metabolic capacities of Actinobacteria and their potential that should be taken into consideration and advantage during the implementation of bioremediation processes in marine ecosystems.

Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential

An overview on the diversity of 39 lectins from the phylum Porifera is presented, including 38 lectins, which were identified from the class of demosponges, and one lectin from the class of hexactinellida. Their purification from crude extracts was mainly performed by using affinity chromatography and gel filtration techniques. Other protocols were also developed in order to collect and study sponge lectins, including screening of sponge genomes and expression in heterologous bacterial systems. The characterization of the lectins was performed by Edman degradation or mass spectrometry. Regarding their physiological roles, sponge lectins showed to be involved in morphogenesis and cell interaction, biomineralization and spiculogenesis, as well as host defense mechanisms and potentially in the association between the sponge and its microorganisms. In addition, these lectins exhibited a broad range of bioactivities, including modulation of inflammatory response, antimicrobial and cytotoxic activities, as well as anticancer and neuromodulatory activity. In view of their potential pharmacological applications, sponge lectins constitute promising molecules of biotechnological interest.

p63 gene structure in the phylum mollusca

Roles of p53 family ancestor (p63) in the organisms' response to stressful environmental conditions (mainly pollution) have been studied among molluscs, especially in the genus Mytilus, within the last 15 years. Nevertheless, information about gene structure of this regulatory gene in molluscs is scarce. Here we report the first complete genomic structure of the p53 family orthologue in the mollusc Mediterranean mussel Mytilus galloprovincialis and confirm its similarity to vertebrate p63 gene. Our searches within the available molluscan genomes (Aplysia californica, Lottia gigantea, Crassostrea gigas and Biomphalaria glabrata), found only one p53 family member present in a single copy per haploid genome. Comparative analysis of those orthologues, additionally confirmed the conserved p63 gene structure. Conserved p63 gene structure can be a helpful tool to complement or/and revise gene annotations of any future p63 genomic sequence records in molluscs, but also in other animal phyla. Knowledge of the correct gene structure will enable better prediction of possible protein isoforms and their functions. Our analyses also pointed out possible mis-annotations of the p63 gene in sequenced molluscan genomes and stressed the value of manual inspection (based on alignments of cDNA and protein onto the genome sequence) for a reliable and complete gene annotation.

Comparison of bioaccumulation and biomarker responses in Dreissena polymorpha and D. bugensis after exposure to resuspended sediments

The zebra mussel Dreissena polymorpha is widely used as sentinel organism for the assessment of environmental contamination in freshwater environments. However, in the River Rhine (Germany), the D. polymorpha population is declining, whereas the closely related quagga mussel D. bugensis is found in high numbers at some sites. In the present laboratory study, D. polymorpha and D. bugensis were exposed to resuspended native sediments for ≤2 weeks. Wet sediments (<63 μm, 100 mg l(-1) dry weight) were used as surrogate suspended particulate matter to mimic one of the mussels' main uptake route for chemicals. The sediments were sampled in (1) the River Elbe in Dessau, a site known to be highly polluted with, e.g., organochlorine (OC) pesticides and (2) at a relatively unpolluted site in Havelberg in the River Havel, one of the Elbe's tributaries. Chemical analysis of persistent OC compounds (seven polychlorinated biphenyls [PCBs], DDT and its metabolites (DDX), hexachlorocylohexanes [HCHs], and hexachlorobenzene [HCB]) in soft tissue of mussels showed significantly greater values of PCBs 101, 118, 153, 138, 180, the sum of seven PCBs, and p,p'-DDD in D. bugensis compared with D. polymorpha. Fourteen days of exposure to Dessau sediment increased the concentration of p,p'-DDE and p,p'-DDD, as well as the sum of DDX, in both species compared with Havelberg sediment. Interspecific differences were less pronounced when regarding chemical concentrations with lipid content instead of dry-weight of tissue because D. bugensis had greater levels of total lipid than D. polymorpha. DNA damage in gills, as measured with the comet assay, was greater in D. bugensis compared with D. polymorpha. Simultaneously, the content of heat-shock protein (hsp70) in gills was greater in D. polymorpha than in D. bugensis. DNA damage and hsp70 were not induced by exposure time or sediment type. This study shows that D. bugensis and D. polymorpha may differ in their bioaccumulation potential of OC pesticides as well as their levels of DNA damage and hsp70. Therefore, more investigations are needed before quagga mussel can be used as alternative test organism for the zebra mussel.

MAP kinase cell signaling pathway as biomarker of environmental pollution in the sponge Suberites domuncula

In the present study, we analyzed the effects of two major pollutants of the environment, tributyltin (TBT) and water-accommodated fraction (WAF) of diesel oil, on MAP kinase activation, apoptosis induction and DNA damage, in the marine sponge Suberites domuncula. Our results clearly demonstrated a differential activation of the MAPKs depending on the chemicals tested. TBT induced the activation of p38 and JNK while diesel oil enhanced activation of both ERK and p38. The activation of MAPKs was observed after 1 h exposure and 6 and 24 h of recovery in seawater. In addition, DNA fragmentation, assessed by two techniques, the Fast micromethod(®) and the TUNEL assay, was detected after sponges were treated with both chemicals. Moreover, the study of caspase 3/7 activity showed that apoptosis was induced and triggered with all concentrations of TBT but only at high diesel oil concentrations. After TBT exposure, a correlation was observed between JNK activation, caspase 3 activity and DNA damage while p38 activation followed the two latter parameters at high concentrations of diesel oil, suggesting that sponges enhanced a specific apoptotic pathway depending on the xenobiotic tested. This study demonstrated a high signal response by the sponge Suberites domuncula to the tested chemicals. Cell signaling pathway studies may thus be of use in water quality biomonitoring programs.

Induction of apoptosis in mussel Mytilus galloprovincialis gills by model cytotoxic agents

Apoptosis signaling pathway was investigated in the marine mussel Mytilus galloprovincialis exposed to various stressors. Analyses were performed in mussels exposed to two major pollutants of the aquatic environment: tributyltin and the water soluble fraction of diesel oil, for 1 h and animals were then maintained in sea water for a recovery period of 6 and 24 h. Apoptosis was evaluated at several levels of the cell signaling cascade by measuring Bcl-xS expression, caspase-3 activity and DNA damage (Fast micromethod(®) and TUNEL techniques). H(2)O(2) was used as a control of apoptosis induction for validation of the assays. Results showed an induction of Bcl-xS expression, a protein implicated in apoptosis, after 1 h exposure to all concentrations of chemicals. Moreover, in the same manner, apoptotic DNA damage was induced with all chemicals tested. Besides, caspase 3 activity was detected after 1 h exposure to low doses of TBT and diesel oil while the high concentrations induced this protein after 6 h. The achieved data were also correlated with our previous study, demonstrating an induction of the mitogen-activated protein kinase (MAPK) activity in the mussel M. galloprovincialis exposed to the same conditions. In conclusion, this study was one of the first characterizing the MAP kinase cell signaling pathway leading to apoptosis in the mussel M. galloprovincialis exposed to chemicals. It showed for the first time that the Bcl-xS protein was present in these mussels as in other species and played a role in apoptosis mediation. Moreover, the main originality of this work was that it showed that two apoptotic pathways might be present in the mussel: a caspase 3-dependent and a caspase 3-independent pathways.

Mytilus galloprovincialis as a bioindicator of environmental conditions: the case of the eastern coast of the Adriatic Sea

The marine mussel Mytilus galloprovincialis lives attached to the surface of hard substrata, where its exposure and relative immobility allow it to record changes in ambient seawater. It is also found along the eastern coast of the Adriatic Sea. Oxygen and carbon isotopes were analysed for calcite and aragonite in separate shell layers, while major, minor and trace elements in the bulk shell were analysed to evaluate environmental conditions such as the temperature of carbonate deposition, freshwater influence and locations of anthropogenic pollution. We found that, on average, aragonite is enriched by 1.1‰ in (13)C and by 0.2‰ in (18)O compared with calcite. The calculated temperatures for M. galloprovincialis shell growth from the investigated area range from 13.4 to 20.9 °C for calcite and from 16.6 to 23.1 °C for aragonite. According to the δ(18)O and δ(13)C values of shell layers, we can separate the investigated area into three locations: those with more influence of freshwater, those with less influence of freshwater and those with marine environments. The highest concentrations of manganese, barium, boron, arsenic, nickel and chromium were observed in shells from Omis, Bacvice and Zablace (Central Adriatic) and Sv. Ivan (South Adriatic), where chemical and heavy industries are located and where sewage is known to be discharged into coastal areas. The highest concentrations of zinc, lead and copper were measured in samples from Pula, Rijeka and Gruz, where there are also ports in addition to industry.

The toxicity of composted sediments from Mediterranean ports evaluated by several bioassays

This work investigates the ecotoxicological evaluation of contaminated dredged sediments from French Mediterranean navy harbour (A), commercial port (B) and two composite specimens (C) and (D) coming from the mixture of A and B with other port sediments. The toxicity of elutriates from these sediments is estimated using embryo-toxicity test, Microtox® solid phase test, LuminoTox, phytotoxicity tests and genotoxicity test. Bioassay responses are not clearly correlated with chemical contamination in the whole sediment and vary as a function of tested organisms. The highest contaminated samples (A and C) are almost always more toxic than the less contaminated samples (B and D). Among composite sediments, the mixture effect with other sediments is not efficient to decrease toxicity in sample C, suggesting that other parameters influence toxicity level such as particle size or organic matter content. These parameters should be taken into consideration in order to improve the efficiency of the mixture process and produce composite sediments with low toxicity.

Activation of MAP kinase signaling pathway in the mussel Mytilus galloprovincialis as biomarker of environmental pollution

Stimulation of MAP kinase signal transduction pathway by various stressful stimuli was investigated in the marine bivalve Mytilus galloprovincialis. Analyses were performed in animals exposed in laboratory to selected pollutants and in mussels collected in winter and summer along the eastern Adriatic coast (Croatia). Effects of oxidative stress, induced by tributyltin, hydrogen peroxide and water soluble fraction of diesel fuel on the activation/phosphorylation of the three Mitogen-Activated Protein Kinases (MAPKs) p38, JNK and ERK using a newly developed ELISA procedure were evaluated. MAP kinase activation was analyzed 1h after exposure of mussels to chemical agents, and after recovery periods of 6 and 24h. Our results clearly indicated that pollutants generated different patterns of induction of the MAPK phosphorylation. Indeed, only pp38 and pJNK were activated with 11, 33 and 100 microg/L TBT, reaching a maximum activation after 6h in seawater following treatment of mussels with 11 microg/L TBT. Treatment with 0.074 and 0.222 mM H2O2 enhanced activation of both p38 and ERK. These two kinases were activated after 1h exposure, followed by a diminution after 6h of recovery in seawater and a reactivation after 24h. The levels of phosphorylated P38 and JNK were increased after mussel exposure with 7.5, 15 and 30% of water soluble fraction of diesel oil. P38 was activated concentration dependently at 1h exposure. Additionally, field study pointed out seasonal differences in MAP kinases activation as mussels collected during summer had a higher enzyme activation state than in winter, as well as sampling site differences which could be correlated to the industrial/tourism activity and environmental stresses (salinity). All the results converge towards MAP kinase signaling pathway being induced by various pollutants in M. galloprovincialis. This signaling cascade should be considered as a possible biomarker of environmental stress and pollution.

Western mosquitofish as a bioindicator of exposure to organochlorine compounds

The evaluation of the alochthonous and cosmopolitan mosquitofish species Gambusia affinis suitability as a bioindicator species and the induction of its liver cytochrome P450-dependent mixed function oxygenase (MFO), measured as the 7-ethoxyresorfin-O-deethylase (EROD) activity, as well as changes in DNA integrity, measured by the Fast Micromethod, for the monitoring of organochlorine fresh water pesticide contamination, were the main aims of the study. The test mosquitofish were exposed under laboratory conditions to several doses (0.1, 10 and 100 microg l(-1)) of lindane in experimental basins for up to 7 days, and a subsequent field study was carried out at five natural ponds in the south-western Istrian peninsula, Croatia, where up to 10 fish were collected from each pond. Results obtained during the studies showed positive correlations between the measured biomarkers in G. affinis liver (EROD activity and DNA integrity status) and lindane (laboratory experiment) or persistent organochlorine pollutant amounts in natural pond sediments (field study). The clear dose-responses of EROD activity and DNA integrity deterioration in G. affinis were recorded after exposure to 0.1-10 microg/l lindane and 96 h exposure to lindane, respectively. The results indicate that the mosquitofish G. affinis, due to its biological-ecological characteristics and the biomarker dose-response, is suitable for the monitoring of fresh water organochlorine pesticide contamination in general and lindane in particular.

Effect of hypoosmotic stress by low salinity acclimation of Mediterranean mussels Mytilus galloprovincialis on biological parameters used for pollution assessment

In the present study, we investigated the progressive acclimation of the mussel Mytilus galloprovincialis to different reduced seawater (SW) salinities and its effect on several biochemical markers and biotests. Mussels were purchased from a local mariculture facility during summer (SW temperature 27 degrees C, salinity 37.5 psu) and winter (13 degrees C, 37 psu) seasons, and transferred to the laboratory for acclimation to reduced SW salinities (37, 28, 18.5 and 11 psu). At the beginning and at the end of acclimation processes tests of mussel survival in air were provided. After 14 days of acclimation the DNA integrity, p38-MAPK activation, metallothionein induction, oxygen consumption rate, and condition index were measured. Survival in air (SOS test), as a physiological index of mussel's health and vitality, had significantly lower LT50 values (11 psu) in the summer than in the winter, and it seems to be negatively affected by acclimation in comparison to controls (37 psu and mariculture). Condition indexes (CIs) were not significantly different, but mussel's acclimation resulted in decline (i.e., a negative trend), especially of CI-2 and CI-3 calculated on the basis of mussel tissue weight and shell sizes. Oxygen consumption rate (VO2) of M. galloprovincialis acclimated to reduced salinities was a concentration-dependent process and increased considerably to about 51 and 65% in lower SW concentrations (28 and 18 psu) compared to control mussels (37 psu). DNA integrity, determined by Fast Micromethod, was negatively impacted by salinity acclimation and corresponding physiological stress as well. Some differences in 1D protein expression patterns between control groups and mussels acclimated to 28, 18.5 and 11 psu (SW) were established. Reduced SW salinities (18.5 and 11 psu) resulted in significantly higher p38-MAPK phosphorylation, whereas the SW salinity of 28 psu decreased p-p38 significantly compared to control (37 psu). The concentration of metallothioneins in mussels' gills was reduced at 28 and 18.5 psu, while it was significantly higher at 11 psu. Results indicated that SW salinity variation (i.e., hypoosmotic stress) in the marine environment can affect all investigated parameters. This investigation expands our understanding of multifactorial effects of the physical marine environment on the specificity of investigated biomarkers and biotests, providing insight into the acclimation, adaptive and stress response processes of mussels. Effects of environmental factors have to be considered in sampling strategies for monitoring programmes to prevent false interpretation of results.

PAH content, toxicity and genotoxicity of coastal marine sediments from the Rovinj area, Northern Adriatic, Croatia

Surface marine sediments collected from 8 sampling sites within the Rovinj coastal area, Northern Adriatic, Croatia, were used for determining priority pollutant polycyclic aromatic hydrocarbons (PAHs) and toxic/genotoxic potential of sediment organic extracts. Total PAH concentrations ranged from 32 microg/kg (protected area) to 13.2 mg/kg dry weight (harbor) and showed clear differences between pristine, urban industrial and harbor areas. PAHs distribution revealed their pyrogenic origin with some biogenic influence in harbor. At all sampling sites sediment extracts showed toxic potential that was consistent with the sediment type. No correlation between toxicity measured by Microtox assay and concentrations of individual or total PAHs was found. Noncytotoxic dose of sediment extracts showed no genotoxic potential in bacterial umu-test. DNA damage is positively related to total PAHs at 4 sampling sites (S-1, S-2, S-3, S-6), but the highest DNA damage was not observed at the site with the highest total sediment PAH content (S-5).

Axial (apical-basal) expression of pro-apoptotic and pro-survival genes in the lake baikal demosponge Lubomirskia baicalensis

Like in all other Metazoa, also in sponges (Porifera) proliferation, differentiation, and death of cells are controlled by apoptotic processes, thus allowing the establishment of a Bauplan (body plan). The demosponge Lubomirskia baicalensis from the Lake Baikal is especially suitable to assess the role of the apoptotic molecules, since its grade of construction is highly elaborated into an encrusting base and branches composed of modules lined up along the apical-basal axis. The four cDNAs, ALG-2, BAK, MA-3, and Bcl-2, were isolated from this sponge species. The expression levels of these genes follow characteristic gradients. While the proapoptotic genes are highly expressed at the base of the branches and comparably low at the top, the pro-survival gene follows an opposite gradient. Parallel with the tuned expression of these genes, the activities of the apoptosis-executing enzymes caspase-8 (IETDase activity) and caspase-3 (DEVDase activity) are lowest at the top of the branch and highest at their base. This characteristic expression/activity pattern of the genes/enzymes, which had been determined in a few specimens, collected from an unpolluted, natural site, appears reversed in specimens collected from an anthropogenically polluted site. These findings indicate the involvement of apoptotic proteins in the axis formation (branches) in L. baicalensis.

Selenium affects biosilica formation in the demosponge Suberites domuncula

Selenium is a trace element found in freshwater and the marine environment. We show that it plays a major role in spicule formation in the demosponge Suberites domuncula. If added to primmorphs, an in vitro sponge cell culture system, it stimulates the formation of siliceous spicules. Using differential display of transcripts, we demonstrate that, after a 72-h exposure of primmorphs to selenium, two genes are up-regulated; one codes for selenoprotein M and the other for a novel spicule-associated protein. The deduced protein sequence of selenoprotein M (14 kDa) shows characteristic features of metazoan selenoproteins. The spicule-associated protein (26 kDa) comprises six characteristic repeats of 20 amino acids, composed of 10 distinct hydrophobic regions ( approximately 9 amino acids in length). Recombinant proteins were prepared, and antibodies were raised against these two proteins. Both were found to stain the central axial filament, which comprises the silicatein, as well as the surface of the spicules. In the presence of selenium, only the genes for selenoprotein M and spicule-associated protein are up-regulated, whereas the expression of the silicatein gene remains unchanged. Finally we show that, in the presence of selenium, larger silica aggregates are formed. We conclude that selenium has a stimulatory effect on the formation of siliceous spicules in sponges, and it may be involved in the enzymatic synthesis of biosilica components.

Stress-70 proteins in marine mussel Mytilus galloprovincialis as biomarkers of environmental pollution: a field study

In the present work we have investigated levels of stress-70 proteins in the gills of mussel Mytilus galloprovincialis collected seasonally from subtidal rocky shores at 6 different sites of the Rovinj coastal area (Northern Adriatic, Croatia). 1-D analysis (SDS-PAGE) using monoclonal mouse antibodies anti-HSP70 detected two bands of stress-70 proteins, 70 and 72 kDa constitutively present during the year. 2-D analysis (IEF+SDS-PAGE) proved that the antibodies used detected HSP70 (pI 5.7-5.9) and HSP72 (pI 5.5-5.6). The quantification of stress-70 proteins was possible using 200 ng of external HSP70 protein standard included on every blot. Maximal levels of HSP72 and HSP70 were observed in mussels in summer (September), and minimal levels in winter (December), and only HSP70 showed significant correlation with the sea temperature (r=+0.822, p<0.05). Acclimatization of mussels to a different lower salinity under experimental conditions proved that small changes in sea salinity (Delta=2 psu) could not cause significant stress-70 proteins induction. Results indicated that there are significant differences in HSP70 and HSP72 content in mussels from the control site (S-1) and mussels from other sampling sites with urban and industrial pollution. The usefulness of stress-70 proteins as biomarkers of environmental pollution is discussed.

Application of alkaline elution, Fast Micromethod and flow cytometry in detection of marine contamination

DNA damage is an inescapable aspect of life in the biosphere. The presented investigations were an attempt to examine the response of a DNA damage as a biomarker of environmental quality in the mussels Mytilus galloprovincialis sampled at differently contaminated areas of Istrian coast, Northern Adriatic. The investigations were performed in order to get information about the genotoxic risk for marine organisms exposed to mixed environmental pollution, as well as the information about the presence of unknown mixture of genotoxic contaminants in the marine environment. Types of DNA damage detected are alkali-labile sites and single-strand breaks measured by Fast Micromethod, interstrand cross-links and DNA protein cross-links by alkaline filter elution and cell cycle disturbation by flow cytometry. The applicability of all three methods for marine quality control is discussed.

Evaluation of the SOS/umu-test post-treatment assay for the detection of genotoxic activities of pure compounds and complex environmental mixtures

This study presents an evaluation of the SOS/umu-test after introducing an additional dilution and incubation in the post-treatment assay. This treatment reduces the influence of coloured test compounds that otherwise affect the colorimetric determination of the beta-galactosidase activity and the bacterial growth measurement during the testing of complex environmental samples. The post-treatment assay significantly increased the beta-galactosidase activity and consequently the enzyme induction ratios at higher doses of model genotoxins 4-nitroquinoline-N-oxide, N-methyl-N'-nitro-N-nitrosoguanidine, 2-aminoanthracene, benzo(a)pyrene with low or no effect on the sensitivity of the test itself. On the other hand tests of environmental extracts indicated significant increases in sensitivity after additional incubation. 4-Nitroquinoline-N-oxide treatments of bacteria in the test affected cell division and caused filamentous growth. The size of filamentous bacteria and incidence rate of the length categories was positively correlated with the concentrations of genotoxins. Presence of filamentous tester bacteria proved induction of SOS response and genotoxic activity of environment samples in SOS/umu-test.

A microplate assay for DNA damage determination (fast micromethod)

A rapid and convenient procedure for DNA damage determination in cell suspensions and solid tissues on single microplates was developed. The procedure is based on the ability of commercially available fluorochromes to interact preferentially with dsDNA in the presence of ssDNA, RNA, and proteins at high pH (>12.0), thus allowing direct measurements of DNA denaturation without sample handling or stepwise DNA separations. The method includes a simple and rapid 40-min sample lysis in the presence of EDTA, SDS, and high urea concentration at pH 10, followed by time-dependent DNA denaturation at pH 12.4 after NaOH addition. The time course and the extent of DNA denaturation is followed in a microplate fluorescence reader at room temperature for less than 1 h. The method requires only 30 ng DNA per single well and could conveniently be used whenever fast analysis of DNA integrity in small samples has to be done, e.g., in patients' lymphocytes after irradiation or chemotherapy (about 3000 cells per sample), in solid tissues or biopsies after homogenization (about 25 microg tissue per well), or in environmental samples for genotoxicity assessment.

Erythromycin-induced torsades de pointes and ventricular fibrillation in a patient with Legionella pneumonia

Several case reports of erythromycin-induced torsades de pointes (TDP) arrhythmia have been reported in the literature. However, this potentially lethal side-effect of a frequently prescribed drug is not generally known. We report a patient who developed TDP followed by ventricular fibrillation during rapid infusion of erythromycin lactobionate. Although the patient used diuretics, probably predisposing her to arrhythmias due to hypokalaemia, several ECG abnormalities predisposing to TDP, all related to erythromycin infusion, occurred during observation in the ICU, establishing the precipitating role of erythromycin. The diagnosis was made only after QT prolongation, TDP and ventricular fibrillation were observed during rapid intravenous infusion of erythromycin lactobionate, one of the reasons no doubt being the assumed lack of serious side-effects of this frequently prescribed drug.

Partial trisomy 4p resulting from a balanced intrachromosomal insertion, 4(q313p14p16)

Partial trisomy 4p was found in a child with dysmorphic features. Cytogenetic investigations in the parents revealed an intrachromosomal insertion in the mother, 46,XX,ins (4) (q313p14p16). The proband was trisomic for 4p(p14p16) as a result of a recombination event in the mother's chromosome 4 at meiosis. The clinical features of the proband are compared with those found in the literature.