178 research outputs found
Knowledge about microplastic in Mediterranean tributary river ecosystems: lack of data and research needs on such a crucial marine pollution source
Perfluorooctanoic acid exposure assessment on common carp liver through image and ultrastructural investigation
Perfluorooctanoic acid (PFOA) poses particular concern as an emerging pollutant in both surface and ground waters. Fish, as a natural inhabitant of these waters and being highly representative of vertebrates, represents an ideal animal model to assess the toxic effects of PFOA. Hereby, liver microscopic texture was comparatively evaluated in individuals of common carp subchronically exposed to PFOA using grayscale differential box counting, a fractal analysis method. Furthermore, liver cytoplasmic glycogen areas and ultrastructure were also evaluated and compared to the image analysis findings. Redundancy Analysis was performed to assess, in summary, how much the variation of fractal dimension and lacunarity was explained by the concentration of PFOA in liver, the mass of liver and the number of proliferating cell nuclear antigen (PCNA)-immunoreactive nuclei. Treatment group ordination was better determined by fractal dimension than lacunarity. Interestingly, a significant complexity increase was associated with the modification of liver microscopic texture due to PFOA exposure. This complexity increase was related to âcloudy swellingâ, possibly representing a primarily adaptive strategy against PFOA challenge, rather than a slight, reversible form of degeneration as traditionally proposed. The occurrence of endoplasmic reticulum stress, unfolded protein reaction and hormetic response was proposed and discussed
Histopathological alterations in Senegal sole, Solea Senegalensis, from a polluted Huelva estuary (SW, Spain)
As a component of a large research project to evaluate the effects of contaminants on fish health in the field, histopathological studies have been conducted to help establish causal relationship between pollutants (heavy metals and aromatic polycyclic hydrocarbonsâPAHs) and histopathological responses in Senegal sole, Solea senegalensis, from an estuary of SW Spain. Heavy metals (As, Zn, Cd, Pb, Cu and Fe) and 16 PAHs (proprietary USEPA) concentrations in water, sediment and tissues (liver and gills) and histopathological alterations in S. senegalensis from three sampling sites of Ria de Huelva estuary during 2004â2006 years have been analysed. The histopathological studies revealed seasonal and spatial differences in the lesion grade of alterations observing the highest lesion grades in fish from Odiel River and autumn season. No significant differences were observed in the alterations prevalence between sampling sites, but significant differences were observed between seasons observing the highest prevalence in autumn season. However, calculated IPAT demonstrated a lowâmoderate impact of pollutants on health fish. Correlations between histopathological alterations and pollutants analysed were observed being heavy metals the group that presented a major number of correlations with alterations in several organs of S. senegalensis. In evaluating the general health of fish, the use of histopathological studies in recommended for making more reliable assessment of biochemical responses in fish exposed to a variety of environmental stressors. Statistical analysis using semiquantitative data on pathological lesions can help to establish correlation between cause (stressor) and effect (biomarker)
Environmental factors driving parasite community composition of European eel in the Comacchio lagoon
Amphipod intermediate host of Polymorphus minutus (Acanthocephala) parasite of waterbirds with notes on ultrastructure of host-parasite interface.
From November 1997 to June 1998, 3118 specimens of Echinogammarus stammeri (Karaman, 1931)(Amphipoda) were collected from the River Brenta (Northern Italy) and exmined for larval helminths
The history of the introduced parasite Anguillicoloides crassus: insights from the case study of the Comacchio lagoon
Ultrastructural Assessment of Granulomas in the Liver of Perch (Perca fluviatilis) Infected by Tapeworm
Summary Granulomas caused by migration of larvae of a helminth parasite, Triaenophorus nodulosus, within the liver of perch (Perca fluviatilis) from Rimov Dam Lake (Czech Republic) were assessed by transmission electron microscopy. Lesions were found in the liver of 29 out of 34 perch examined (85.2%) and there were between 1 and 15 T. nodulosus larvae identified per host. Pathological changes were more severe in livers containing more granulomas. Within the granulomas, there were three concentric regions: an outer layer of fibrous connective tissue, a middle clear epithelioid layer and a central dark spindle cell layer. The outer layer contained mast cells, fibroblasts, thick collagen bundles and epithelioid cells. The granulomas contained few lymphocytes and macrophages. Hepatocytes adjacent to the granulomas showed pronounced degeneration (ranging from vacuolar degeneration to acute cellular swelling)
Granulomatosi viscerale in un esemplare di oranda (Carassius auratus auratus L.). Aspetti necroscopici, istopatologici e diagnostici differenziali.
Ă riportato il caso di un pesce rosso (Carassius auratus auratus L.) dâacquario deceduto a seguito di una granulomatosi viscerale dopo due mesi di apatia. Alla necroscopia si riscontravano lesioni
nodulari principalmente a carico del pronefro e mesonefro, istologicamente rilevate anche nel fegato, nella milza e nel cuore. Nonostante lâutilizzo di colorazioni volte allâevidenziazione
di agenti patogeni batterici, fungini e protozoari (Giemsa, McCallum-Goodpasture, Ziehl-Nielsen, PAS, Alcian Blue - PAS pH 2,5) non si riscontrava noxa patogena alcuna. Il quadro
necroscopico ed istopatologico riscontrato era compatibile con tubercolosi ittica e granulomatosi sistemica del pesce rosso
Gastrointestinal helminths infection and digestive hormones in the fish-parasite systems
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