1,720,959 research outputs found
A promising novel aquatic model for assessing cellular and physiological response to personal care product additives
No full textOriginating from the Pacific Ocean, the pearl oyster Pinctada imbricata (Röding, 1798) stands as one of the first “Lessepsian migrants” to reach the Mediterranean Sea via Suez. Since the 2000s, the species has established a successful population in the transitional waterways of the “Capo Peloro Lagoon natural reserve”, exhibiting exceptional abundance owing to its remarkable adaptability across various hydrological, climatic, environmental, and pollution conditions. With reference to recent studies1,2 and considering its biological traits, P. imbricata appears to embody the qualities of an effective bioindicator and model organism for ecotoxicological investigations. The relevance of the availability of suitable bioindicators and model organisms stems from the growing awareness of identifying and addressing stress conditions that affect aquatic ecosystems, primarily due to human-induced pressures. Effectively, aquatic ecosystems are among the main target environments for biomonitoring strategies, as they represent one of the main receptors of pollutants. For instance, the COVID-19 pandemic has increased the use of personal hygiene products, containing compounds, e.g. preservatives, that may threaten aquatic ecosystems. Preservatives include various categories including quaternary ammonium compounds (QACs), recognized for their ability to withstand metabolic degradation and persistence in wastewater due to their lipophilic nature. Among QACs is quaternium-15, which is widely incorporated in various personal care products (PCPs). Therefore, this study aims to assess the physiological and cellular responses of P. imbricata's haemocytes to different concentrations of quaternium-15 (0.1 and 1 mg L-1) in vitro, to determine the suitability of the species as an experimental model in ecotoxicological studies and the toxicity of the substance. The investigation included cell viability and phagocytosis assays, along with modulation of γ-actin (γAct) and oxidative stress-related gene expression (Cat, MnSod, Zn/CuSod, GPx). Findings revealed a significant reduction in haemocyte viability and phagocytosis activity after exposure to both concentrations. The decreasing phagocytosis activity was also supported by the gene expression modulation of γAct, which is involved in cytoskeleton rearrangement. The qPCR data revealed significant alterations in the antioxidant response, resulting in the upregulation of Cat and GPx and the downregulation of MnSod and Zn/CuSod. These data indicate that exposure to quaternium-15 caused harmful effects on the immune-mediated response of haemocytes, which act as the primary defence mechanism for bivalve molluscs against xenobiotics. Additionally, there is evidence of a time and dose-dependent response, highlighting the importance of exploring sustainable alternatives to replace harmful additives in PCPs and promoting P. imbricata as a valuable model for future ecotoxicological studies.
1Kuchel, R.P., et al. (2010). Haemocyte morphology and function in the Akoya pearl oyster, Pinctada imbricata. J. Invertebr. Pathol., 105(1), 36-48.
2Pagano, M., et al. (2023). A first insight into haemocytes of Pinctada imbricata radiata: A morpho‐functional characterization. Micros. Res. Techniq., 86(3), 368-377
A first insight into haemocytes of Pinctada imbricata radiata: A morpho-functional characterization
No full textThe pearl oyster Pinctada imbricata radiata (Leach, 1814), from the Pacific Ocean, was one of the first species to reach via Suez the Mediterranean, colonizing the eastern basin and recently spreading to the western. The species showed to be able to adapt to a wide range of climatic, hydrological, and ecological conditions. Since 2000 it reached the Strait of Messina, where is now infesting the transitional waters of the oriented natural reserve "Laguna di Capo Peloro." Due to such resistance and adaptation ability, various assays were performed. Haemocyte morpho-functional aspects were evaluated in haemolymph samples fixed with 1% and 2% glutaraldehyde for optical and electron microscopy (TEM). The following assays were carried out: cell characterization using several dyes, detection of intra- and extracellular lipids, the capability of phagocytosis using the yeast Saccharomyces cerevisiae and to produce superoxide anion (O2- ). Detection of several enzymes, such as acid and alkaline phosphatase, arylsulfatase, chloro-acetylesterase and β-glucuronidase was also assessed. Cell count was demonstrated to be abundant with a mean of 8.263 × 106 mm2 ± 0.935 × 106 (SD). Two main cell populations were noticed: granulocytes and hyalocytes, both competent for phagocytosis, to produce O2- , and characterized by lipids. Based on the granule analysis, enzymatic activity was also demonstrated. The observations under TEM confirmed all the results obtained. This study supports the hypothesis that P. imbricata radiata can be usefully employed as a model organism in environmental biomonitoring. Moreover, since the species represent potential threats to native species and ecosystems, further insights into its biological adaptations in invaded ecosystems are recommended
Evaluation of physiological changes in Mytilus galloprovincialis exposed to an isothiazolinone-based compound: A multi-marker approach
No full textThe present study aims to assess, through a multi-marker analysis, the changes in physiological parameters in the Mediterranean mussel, Mytilus galloprovincialis, due to exposure to methylchloroisothiazolinone (CMIT). The CMIT is an isothiazolinone-based compound widely employed in the formulations of several commercial products as a biocidal agent. The increasing use of isothiazolinones, especially during the COVID-19 pandemic, has increased concerns about the health of the ecosystem. Therefore, in the present study, specimens of M. galloprovincialis were exposed to environmentally relevant sub-lethal concentrations of CMIT (0.01 and 0.1 mg L-1) for 14 days. Responses in target tissues such as haemolymph (H), digestive gland (DG), and gills (G) were assessed. Cytotoxicity and phagocytosis ability were analysed in haemocytes. Also, cytotoxicity was measured in DG cells along with cell ability to respond to osmotic shock via the Regulatory Volume Decrease (RVD) assay. In G, oxidative stress indexes (protein carbonylation, TBARS, and superoxide dismutase) were measured. Findings indicated alterations in cell physiological functionality and osmoregulatory response as well as high vulnerability of biochemical responses. These results demonstrate the potential toxicity of CMIT on key physiological and biochemical parameters. This basic research exploits potency and lays the groundwork for future studies that will fully elucidate the effects of isothiazolinones on model organisms and the wider ecosystem, and indirectly on human health
Novel sustainable strategies to mitigate toxicity of emerging contaminants: cellular and physiological insights from CMIT-exposed mussels treated with insect-based protein hydrolysates
No full textThe present interest in developing sustainable strategies to mitigate or prevent toxicity of emerging contaminants is attributable to their increasing occurrence in natural ecosystems. Beyond their established roles in the agri-food, feed, and biotechnology sectors, insects are emerging as valuable sources of bioactive compounds, highlighting their recognition as sustainable solutions in nutraceutical and pharmaceutical research. Therefore, the effects of protein hydrolysates from the black soldier fly, Hermetia illucens (BPHs) were evaluated against the toxicity induced by the methylchloroisothiazolinone (CMIT), a widely used biocides belonging to the isothiazolinones class of the biocides. Analyses focused on the modulation of key cellular and physiological parameters in Mytilus galloprovincialis exposed to CMIT (0.01 mg/L), BPHs (0.5 mg/mL), and their mix. Changes in haemocyte functions were assessed through cell viability assays and phagocytosis assay along with the expression of γ-actin; investigation into digestive gland (DG) functionality was carried out by measuring the viability of DG cells and their ability to perform osmoregulation after a hypotonic shock through the Regulatory Volume Decrease video-metric assay (RVD); antioxidant and cytoprotective responses were evaluated through the Cu/ZnSOD, MnSOD, Hsp70, and CYP4Y1 gene expression analysis. Our findings showed that BPHs play a significant protective role against toxicity induced by CMIT in exposed mussels. Significant differences emerged between the control and the CMIT-treated groups, whereas a similar trend was observed between the CTRL and BSPHs-exposed groups. Groups exposed to the combinations (BPHs + CMIT) showed a recovery, suggesting the protective effect of this compound
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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