414 research outputs found
First evidence of microplastics ingestion in benthic amphipods from Svalbard
No full textThe present paper provides the first record of ingestion of microplastics in natural context by Gammarus setosus from Svalbard Archipelago. The plastic particles were identified both by Nile Red staining and Micro FT-IR spectroscopy. The species studied ingests microplastic particles in natural conditions if present in its habitat, probably mistaking them as food. The microplastic particles ingested may be available for uptake to predators that consume this Arctic amphipod, producing consequences to the food web
Genotoxicity biomarkers in the amphipod Gammarus elvirae exposed in vivo to mercury and lead and basal levels of DNA damage in two cell types
No full textThe present work deals with the application of genotoxicity biomarkers by means of the Comet assay in haemocytes and spermatozoa of the crustacean Gammarus elvirae exposed in vivo to heavy metals. Furthermore, a basal levels (BLs) study of DNA damage in the two cell types considered for two different gammarids species, G. elvirae and Echinogammarus veneris, was carried out. It is important to identify factors that influence the outcome of the assay in order to obtain reliable and reproducible results usable for risk assessment purposes. Our results highlight that the Italian legal limits for Hg and Pb, respectively, 0.5 and 50 μg/L, are inadequate for establishing safety thresholds in the aquatic environment. Furthermore, the freshwater invertebrate G. elvirae, used for the first time to measure the effect of genotoxicants, is a good candidate for evaluating the genotoxicity damage induced by heavy metals. Our results concerning spermatozoa show excessively variable responses and high BLs
Immunological characterization and cytochemical distribution of monoamine oxidase in rainbow trout.
No full textAntinuclear antigen expression and allergic contact dermatitis in subjects occupationally exposed to allergens
No full textMolecular characterization of monoamine oxidase in zebrafish (Danio rerio)
No full textMonoamine oxidase (MAO) is responsible for the degradation of a number of neurotransmitters and other biogenic amines. In terrestrial vertebrates, two forms of the enzyme, named MAO A and B, were found in which mammals are coded by two similar but distinct genes. In teleosts, the biochemical data obtained so far indicate that enzyme activity is due to a single form, whose sequence, obtained for trout, displays 70% identity with mammal MAO A and B. In this paper, we carried out an investigation of zebrafish MAO (Z-MAO) to shed further light on the nature of the MAO form present in aquatic vertebrates. Sequencing studies have revealed an open reading frame 522-amino-acids long with MW 58.7 kDa, displaying 84% identity with trout MAO and about 70% identity with mammal MAO A and MAO B. Analysis of the sequence and of the predicted secondary structure shows that also in Z-MAO principal domains characterizing the MAOs are present. The domain linking the FAD is very well conserved, while the transmembrane domain sequence linking the enzyme to the external mitochondrial membrane does not appear to be conserved even with respect to trout MAO. Comparison with the amino acids which, according to the human MAO B and rat MAO A models, line the substrate-binding site shows that in Z-MAO, several residues (V172, N173, F200, L327) differ from MAO B but are similar or identical to the corresponding ones present in rat MAO A, as well as in trout MAO. A three-dimensional model is reported of the substrate-binding site of Z-MAO obtained by comparative modeling. Our observations support the hypothesis that the MAO form present in aquatic vertebrates is a MAO A-like form. Experiments performed to test the effect of selective MAO A (clorgyline) and MAO B (deprenyl) inhibitors on the enzyme's activity in liver and brain confirm the presence of a single form of MAO in zebrafish. (C) 2004 Elsevier Inc. All rights reserved
Plastic abundance and seasonal variation on the shorelines of three volcanic lakes in Central Italy: can amphipods help detect contamination?
No full textDespite the exponential increase of studies on plastic debris in recent years, there are still few works focusing on the problem as it relates to inland waters: little is known about the accumulation and dispersion dynamics on lake shores, and there are no standardized sampling methods for monitoring purposes. The accumulation of plastic litter in natural habitats also threatens the resident organisms. In this paper, we investigated the abundance and accumulation of plastic particles, ranging in size from 1 to 50 mm, from the beach sediment of three volcanic lakes in Central Italy: Albano, Bracciano, and Vico. The collection was designed to define the most important variables that one must consider in order to obtain a representative sample of plastic litter in a lake environment. In view of the high heterogeneity of sampling protocols used, comparison among the obtained results is limited and sometimes impossible. By using one of the proposed sampling methodologies, and critically analyzing the results, we aimed to highlight a possible monitoring criterion and to identify specific elements that can be meaningful and representative. The samples were collected in May and September 2017. For each lake, we sampled plastic items and sediments from two beaches. Albano contained the largest amount of plastic (in weight), while Bracciano had the largest number of particles. Our observations lead us to infer that the number of particles is the parameter most sensitive to environmental variations, as well as the more suitable for monitoring with greater definition the differences between sites. Moreover, sampling should be taken in different seasons, following a sampling pattern that includes at least two beaches placed in strategic positions with respect to wind and waves. In order to identify new indicators to evaluate the entry points of plastic into the food web, we collected, from the same sites analyzed, some specimens of the Talitrid Amphipod Cryptorchestia garbinii, a detritivorous species having a critical role in debris turnover of these environments. To investigate the microplastic (MP) ingestion in natural conditions, we analyzed their digestive tracts with both Nile red staining method and micro-FTIR spectroscopy. The analyses confirmed that C. garbinii was able to ingest plastics in natural conditions. Therefore, it can signify one of the entry points for microplastics (MPs) in the trophic chain. This observation constitutes the first evidence of MP ingestion in this species
Molecular and cellular responses to short exposure to bisphenols A, F, and S and eluates of microplastics in C. elegans
No full textBisphenol F (BPF) and bisphenol S (BPS) have been developed as an alternative to bisphenol A (BPA), a well-known endocrine disruptor, leading to their detection in the aquatic environment. In this work, we used the animal model Caenorhabditis elegans to improve our understanding of their potential effects on the biota and the environment. Our findings demonstrated that, after 24 h exposure, all the bisphenols examined increased the number of apoptotic corpses and the expression of the detoxifying enzymes SOD-3 and GST-4, without affecting the ROS levels, while BPA and BPS significantly enhanced DNA fragmentation. Furthermore, similarly to BPA, BPF and BPS did not alter the lifespan through the activation of SEK-1 and SKN-1 pathways. Thus, this study raises the attention of the risks associated with exposure to BPA alternatives. We also examined the effects of microplastic (MP) eluates on C. elegans. Aqueous extracts of weathered microplastic samples, both at high and low degradation state and pellets, have been evaluated for their effects on lifespan, DNA fragmentation, germline apoptosis, and oxidative stress response. Overall, our findings showed that eluates of low degraded plastics exert a greater toxic effect on the nematode C. elegans compared with the aqueous sample of high degraded plastic fragments and pellets
Valutazione del danno al DNA e di alterazioni ultrastrutturali nel fegato e rene di Danio rerio esposto a concentrazioni consentite dalla normativa vigente in Italia di Nichel e Cadmio .
No full textGenotoxicity biomarker in the amphipod Gammarus elvirae exposed in vivo to Mercury and Lead.
No full textThe present work deals with the development and validation of genotoxicity biomarker by use of the Comet assay in two cells type, haemocytes and spermatozoa, of the crustacean Gammarus elvirae exposed to heavy metals. In the first part of the study, gammarids were collected and maintained in uncontaminated freshwater and exposed in laboratory standard condition to mercury and lead, in order to evaluate the feasibility of the test, to better understand time and concentration of action of these two heavy metals and checking the effectiveness of limits concentrations currently accepted in Italian legislation; 0.5 μg/l for Hg and 50 μg/l for Pb. At this purpose mercury and lead in vivo exposure concentrations was chosen closest to concentration limits.
The second part of this work focuses on the study of basal levels of DNA damage in the two cells type considered in two different gammarids species, G. elvirae and Echinogammarus veneris, in order to establish a clear and stable basal leve
Preliminary observations on the effect of light and temperature on the hatching success and rate of Lepidurus arcticus eggs
No full textDormancy, which arrests development, is a well-known survival strategy among animals living in the Arctic to overcome harsh periods. It is not clear if the dormant state in notostracans is controlled endogenously (diapause) or exogenously (quiescence). For Lepidurus arcticus, it is unknown how it responds to the photoperiod entrainment, if it has a biological clock and if it has a rhythmic expression of the clock genes. We studied the hatching success of resting eggs at four constant temperatures (5, 10, 15 and 25 °C) and under different illumination regimes [continuous light (LL) and continuous dark (DD)]. It was assumed that light and temperature are both important triggers, with temperature having the most pronounced effect. In our experiment, hatching occurred only at 5 and 10 °C, while we did not observe hatching at 15 and 25 °C. The highest percentage of eggs hatched was at 10 °C in LL (60%); the lowest was at 5 °C in DD (18%). The percentages hatched at 5 °C in LL (24%) and at 10 °C in DD (26%) were similar. Our results indicate that both temperature and light had a significant and interacting effect on hatching in L. arcticus, with temperature being the dominant factor controlling the process. This suggests that changes in temperature affecting the Arctic may significantly impact phenology of this key species in the region. Given that no hatching was observed at 15 °C or above, the persistence of this species may be at risk in areas were arctic lakes are expected to warm to such levels during the summer months
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