1,721,342 research outputs found
Un pericolo invisibile: l’inquinamento ambientale minaccia la conservazione dei condroitti nel Mar Mediterraneo
Full text linkAssessment of the conservation status of Chondrichthyans: underestimation of the pollution threat
Full text linkCartilaginous fish include sharks, rays, skates, sawfish, and chimaeras. Their habitat ranges from shallow coastal waters to deep ocean floors, estuarine areas as well as rivers and inland waters. Overfishing is considered to be the main threat to their existence, but there are many more stressors that these species face. Pollution is an issue that concerns aquatic organisms at every level, and Chondrichthyans are no exception. Here, we looked at their IUCN Red List assessment, and noticed a lack of information regarding anthropogenic contamination for these species. Out of 1124 cartilaginous fish species assessed, only 17 Selachimorpha and 32 Batoidea species were considered to be facing a “pollution threat”; in most cases, the threat was assigned not from direct ecotoxicological studies of the specimens, but because the species inhabited areas likely to be contaminated. An update on the conservation status of these species is urgently needed. Further, there is a fundamental need to study the effects of contaminants on Chondrichthyans as they play a key role in aquatic ecosystems
The use of nondestructive biomarkers in the study of marine mammals
No full textMarine mammals have been subject to heavy anthropogenic pressure by direct killing and chemical pollution all over the world. Most studies of contamination and biomarker responses in marine mammals have been conducted using animals killed by hunting (out of a total of 12 cetacean species studied, 45% of the specimens were obtained by sacrificing the animal; out of a total of eight pinniped species studied, 40% of the specimens were obtained by killing). The development of a series of non-destructive techniques to evaluate biomarker responses and residue levels is recommended for the hazard assessment and conservation of endangered species of marine mammals. Here we review the current status of the non-destructive biomarker approach in marine mammals, describing the biological materials available for non-destructive tests in stranded (brain, liver, blood, skin, subcutaneous blubber, muscle and fur) and free-ranging animals (blood, skin biopsy, fur and faeces) and the respective biomarker techniques (mixed function oxidase activity and DNA damage in skin biopsy samples; porphyrins in faeces and fur; esterases, porphyrins, clinical biochemical parameter, vitamin A and micronuclei in blood samples). Residue analysis can be carried out in the various biological materials. We also report the results of applying this methodological approach to cetaceans (minke whale Balaenoptera acutorostrata, fin whale -Balaenoptera physalus, beluga whale - Delphinapterus leucas, short-finned pilot whale - Globicephala macrorhynchus, harbour porpoise - Phocoena phocoena, Risso's dolphin - Risso's Grampus griseus, Dall's porpoise - Phocoenoides dalli dalli, melon-headed whale - Peponocephala electra, bottlenose dolphin - Tursiops truncatus, striped dolphin - Stenella coeruleoalba, spinner dolphin - Stenella longirostris, killer whale - Orcinus orca) and pinnipeds (northern fur seal Callorhinus ursinus, hooded seal - Cystophora cristata, grey seal - Halichoerus grypus, harbour seal - Phoca vitulina, ringed seal - Phoca hispida, harp seal - Phoca groenlandica, ribbon seal - Phoca fasciata, largha seal Phoca largha, southern sea lion - Otaria flavescens) in field studies for prognostic and diagnostic purposes
Non lethal tools to assess the toxicological hazard of endocrine disruptor organochlorine contaminants in mediterranean cetaceans
No full textThe Mediterranean top predators, and particularly cetacean odontocetes, accumulate high concentrations of organochlorine contaminants (OCs), incurring high toxicological risk. Some organochlorine compounds, now with worldwide distribution, are known as endocrine disrupting chemicals (EDCs). Here the hypothesis that some Mediterranean cetaceans (Stenella coeruleoalba, Delphinus delphis, Tursiops truncatus and Balaenoptera physalus) are potentially at risk due to organochlorines with endocrine disrupting capacity is investigated. As “diagnostic” tool we use benzo(a)pyrene monooxygenase (CYP1A1) activity in marine mammal skin biopsies (non-lethal biomarker) as a potential indicator of exposure to organochlorines, with special reference to the compounds with endocrine disrupting capacity. A statistically significant correlation was found between BPMO activity and organochlorine EDs levels in skin biopsies of males of Balaenoptera physalus. A statistical correlation was also found between BPMO activity and DDT levels in skin biopsies of the endangered Mediterranean population of Delphinus delphis. As “prognostic” tool we propose the immunofluorescence technique in fibroblast cell cultures, for a qualitative and quantitative evaluation of the target proteins as CYP450 1A1-1A2, CYP450 2B4 and estrogen receptor (ER)
New tool to investigate toxicological hazard due to endocrine disruptors in mediterranenan cetaceans
No full textMediterranean cetaceans, particularly odontocetes, accumulate high concentrations of organochlorine contaminants (OCs) and are therefore exposed to high toxicological risk. Some OCs are known to be endocrine disrupting compounds (EDCs). The hypothesis that Mediterranean cetaceans (Stenella coeruleoalba, Delphinus delphis, Tursiops truncatus and Balaenoptera physalus) are subject to toxicological risk due to organochlorines and emerging contaminants, such as polybrominated diphenyl ethers (PBDEs) with endocrine disrupting
capacity, was investigated using non-lethal “diagnostic” and “prognostic” methods. CYP1A1 activity induction (Benzo(a)pyrene monooxygenase) in skin biopsies was used as a “diagnostic” indicator of exposure to organochlorines in odontocetes and mysticetes and in different populations of Stenella coeruleoalba. Marked differences in levels of OCs and CYP1A1 activity were found between fin whales and odontocetes. Organochlorine levels and CYP1A1 activity were significantly higher in the Stenella coeruleoalba population of the Mediterranean Whale Sanctuary than in those of two other study areas, suggesting that cetaceans are exposed to high risk in this protected area. Several questions remain still unanswered in ecotoxicological studies of Mediterranean cetaceans. The need for new biomarkers for EDCs and for a “cell model” to explore the different susceptibilities to several classes of ECDs, including emerging contaminants, led us to culture fibroblasts of different cetacean species as a non-lethal new investigation tool (“dolphins in test tubes”). As a new “prognostic” tool we explored interspecies and gender susceptibility to OC-EDCs and PBDEs using qualitative and semi-quantitative evaluation of target proteins, such as CYP1A1 and CYP 2B in cultured cetacean (Stenella coeruleoalba, Tursiops truncatus and Balaenoptera physalus) fibroblasts, by western blot, immunofluorescence technique and PCR real time. The information obtained in this pilot experiment will be the basis for further applications and validation of these methodologies to expolore different species and gender susceptibility of marine mammals to different mixtures of endocrine disrupting xenobiotics including emerging contaminants
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Influence of cadmium on PCB congener accumulation in quail
No full textTechnological development this century has led to an environmental input of
synthetic chemical compounds totally extraneous to natural ecosystems.
Polychlorobiphenyls (PCBs), extensively used in agriculture and industry, belong
to this class of compounds. These xenobiotics have a high fat/water repartition
coefficient, making them easily accumulated by living organisms. Their
persistence and low degradability means that they are now present throughout the
global ecosystem.
Ubiquitous environmental contaminants also include heavy metals like Hg, As,
Pb, CA and Cr, of which CA, an element causing functional damage to the kidney
and liver in which it preferentially aceumulates, is of special ecotoxicological
importance. The WHO has defined an accumulation limit of 60 mg/kg (fresh
weight), beyond which damage occurs. CA occurs "naturally" in high
concentrations in certain animal species including molluscs. Birds and marine
mammals feeding largely on cephalopods show high levels of this metal (Furness
& Hutton 1979, Honda et al. 1983). Many monitoring studies have also revealed
high concentrations of PCBs in the same animals (Renzoni et al. 1986, Tanabe et
al. 1983)
Movement disorders in oncology: From clinical features to biomarkers
Full text linkBackground: the study of movement disorders associated with oncological diseases and anticancer treatments highlights the wide range of differential diagnoses that need to be considered. In this context, the role of immune-mediated conditions is increasingly recognized and relevant, as they represent treatable disorders. Methods: we reappraise the phenomenology, pathophysiology, diagnostic testing, and treatment of movement disorders observed in the context of brain tumors, paraneoplastic conditions, and cancer immunotherapy, such as immune-checkpoint inhibitors (ICIs). Results: movement disorders secondary to brain tumors are rare and may manifest with both hyper-/hypokinetic conditions. Paraneoplastic movement disorders are caused by antineuronal antibodies targeting intracellular or neuronal surface antigens, with variable prognosis and response to treatment. ICIs promote antitumor response by the inhibition of the immune checkpoints. They are effective treatments for several malignancies, but they may cause movement disorders through an unchecked immune response. Conclusions: movement disorders due to focal neoplastic brain lesions are rare but should not be missed. Paraneoplastic movement disorders are even rarer, and their clinical-laboratory findings require focused expertise. In addition to their desired effects in cancer treatment, ICIs can induce specific neurological adverse events, sometimes manifesting with movement disorders, which often require a case-by-case, multidisciplinary, approach
Endocrine Disruptors in Mediterranean Top Marine Predators
No full textBackground, Aims and Scope. Man-made Endocrine Disruptors (EDs) range across all continents and oceans. Some geographic areas are potentially more threatened than others: one of these is the Mediterranean Sea. Levels of some xenobiotics are much higher here than in other seas and oceans. In this paper we review the final results of a project in which the hypothesis that Mediterranean top predator species (such as large pelagic fish and marine mammals) are potentially at risk due to EDs was investigated.
Methods. In a four-year survey on the Mediterranean population of swordfish (Xiphias gladius), the potential toxicological effects of organochlorine compounds (OCs) on specimens of swordfish and tuna fish (Thunnus thynnus thynnus), caught in the spawning seasons from 1999 to 2002 in the Straits of Messina, Sicily (Italy), were investigated using vitellogenin (Vtg), Zona radiata
proteins (Zrp), and cytochrome P4501A (CYP1A) activities
(EROD, BPMO).
Tissues (skin and blubber) were obtained from Stenella coeruleoalba, Tursiops truncatus, Delphinus delphis and Balaenoptera physalus from the western Ligurian Sea, between Corsica and the French-Italian coast, and Ionic Sea using biopsy darts launched with a crossbow. Benzo(α)pyrene monoxigenase (BPMO) activity was mesured in biopsies and cholrinated hydrocarbon levels were detected.
Results and Discussion. We illustrate the need to develop and apply sensitive methodological tools, such as biomarkers (Vitellogenin, Zona Radiata proteins and CYP1A activities) for evaluation of toxicological risk in Xiphias gladius and Thunnus thynnus thynnus), and nondestructive biomarkers (CYP1A activities and fibroblast cell culture in skin biopsy), for the hazard assessment of threatened marine mammals species (Stenella coeruleoalba, Tursiops truncatus, Delphinus delphis and Balaenoptera physalus) exposed to EDs.
Conclusion. The present research shows that: a) Vtg and Zrp can be used as diagnostic tools for fish stocks hazard assessment in the Mediterranean Sea; b) that CYP1A1 (BPMO) induction in cetaceans skin biopsy may be an early sign of exposure to EDs such as OCs and a potential alert for transgenerational effects.
Recommendation and Outlook. This research represents a warning signal of the potential reproductive alterations in marine top predators and suggest the need for continuous monitoring to avoid reductions in population and biodiversity in the Mediterranean Sea
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