1,720,974 research outputs found
Chironomid mouthpart deformities as indicator of environmental quality: a case study in Lake Trasimeno (Italy)
No full textThe aim of the present study was to monitor mouthpart deformities of Chironomus plumosus (Insecta-
Diptera) in Lake Trasimeno (2000–2010) in relation with sediment contamination by heavy metals,
which is one of the main causes of deformity induction. In Lake Trasimeno, concentrations of heavy
metals in the investigated littoral zone were low, in comparison with those of the central area. By
contrast, the incidence of deformities was much higher in the littoral station (2006–2009) than in the
central area. In the littoral zone, the deformities progressively decreased and by 2010 reached values
similar to those observed in the central area (2000–2002, 2010). This decrease was mainly due to the
reduction of severe deformities, thus indicating an environmental quality recovery of this littoral sector.
Chemical analysis revealed that the higher incidence of deformities in the littoral zone was not caused
by heavy metal contamination, unless they may have contributed to a joint action with other toxicants.
The present study on Lake Trasimeno provided additional evidence that chironomid mouthpart
deformities can be used in biomonitoring programs to evaluate sediment contamination by toxicants.
Since mouthpart deformities may also be induced by compounds not included in routine chemical
analyses, they may better reflect sediment quality than chemical analysis alone
Ampiamento dell’area di distribuzione di Melanargia arge (Lepidoptera, Satyridae) in Umbria
No full textThe tubificids (Annelida, Oligochaeta) of Lake Trasimeno and Lake Piediluco in Central Italy, with a study of SEM morphology of some species
No full textFreshwater oligochaetes are studied worldwide because of their relevance as bioindicators in aquatic ecosystems.
Nevertheless, species identification is still difficult because it is mainly based on the male reproductive system. The morphology of the chaetae offers an additional set of characters and the fine organization of these elements can help in solving crucial aspects allowing specific attribution. In spite of this, somatic chaetae are poorly investigated under scanning electron microscopy (SEM). A SEM analysis of the chaetae has been carried out on the tubificids Branchiura sowerbyi, Limnodrilus hoffmeisteri, Tubifex tubifex,
and Psammoryctides barbatus from Trasimeno and Piediluco lakes (Central Italy). In particular, the chaetal pattern of B. sowerbyi is comparable to that described for specimens from the tropical regions of Asia, and T. tubifex shows the chaetal pattern typical of the nominal species; the palmate chaetae of P. barbatus are characterized by 15–20 fringes, each of them with a distal end thinner and folded backwards. In addition, B. sowerbyi is the dominant species in Lake Trasimeno, whereas it is lacking in Lake Piediluco, where the tubificids are primarily represented by T. tubifex
Actinosporeans of Myxozoan parasites of oligochaetes from Nera River basin, Central Italy
No full textMalformazioni delle larve di Chironomus riparius Meigen, 1804 e contaminazione da metalli pesanti in un corso d’acqua dell’Italia centrale.
No full textDeformities of chironomid larvae and heavy metal pollution: from laboratory to field studies
No full textMouthpart deformities of Chironomus riparius larvae (Diptera) have been investigated to evaluate the toxic effects of contamination by heavy metals in the Genna Stream (Central Italy), situated in an area subjected to intensive swine farms (40,000 heads). The livestock farming (fertirrigation) contributes to metal pollution of the Genna Stream with an increase of copper, zinc, cadmium, chromium and nickel in the sediments of the downstream stations. The incidence of mentum deformities was very high at all sampling stations, about 56%. The highest values of deformities were found in the intermediate river reach (St. 3: 65%) and in March (66%), mainly due to an increase in severe deformities. The high incidence of severe deformities (30%) is attributed to the high pollution level by heavy metals in the sediments, in particular to copper and zinc, which showed the highest average value at St. 3 and in March. This field study reflected the relationships between sediment metal concentrations and chironomid mouthpart deformities, previously observed in laboratory tests, and highlighted these deformities as toxicity endpoints. This feature paves the way for their use as an effective tool in freshwater bioassessment monitoring programs to evaluate the toxic effects of metal contamination in freshwater ecosystems
Induction of mouthpart deformities in chironomid larvae exposed to contaminated sediments.
No full textThe aim of the present study was to improve the cause-effect relationship between toxicant exposure and chironomid mouthpart deformities, by linking induction of mouthpart deformities to contaminated field sediments, metal mixtures and a mutagenic polycyclic aromatic compound metabolite (acridone). Mouthpart deformities in Chironomus riparius larvae were induced by both the heavy metal mixture and by acridone. A clear correlation between metal concentrations in the sediment and deformities incidence was only observed when the contaminated field sediments were left out of the analysis, probably because these natural sediments contained other toxic compounds, which could be responsible for a higher incidence of deformities than predicted by the measured metal concentrations only. The present study clearly improved the cause-effect relationship between toxicant exposure and the induction of mouthpart deformities. It is concluded that the incidence of mouthpart deformities may better reflect the potential toxicity of contaminated sediments than chemical analysis
Lipostar, a Comprehensive Platform-Neutral Cheminformatics Tool for Lipidomics
No full textTo date, the main limitations for LC-MS-based untargeted lipidomics reside in the lack of adequate computational and cheminfor-matics tools that are able to support the analysis of several thousands of species from biological samples, enabling data mining and automating lipid identification and external prediction processes. To address these issues, we developed Lipostar, a novel vendor-neutral high-throughput software that effectively supports both targeted and untargeted LC-MS lipidomics, implementing data ac-quisition, user-friendly multivariate analysis (to be used for model generation and new sample predictions), and advanced lipid iden-tification protocols that can work with or without the support of preformed lipid databases. Moreover, Lipostar integrates the lip-idomic processes with a full metabolite identification (MetID) procedure, essential in drug safety applications and in translational studies. Case studies demonstrating a number of Lipostar features are also presented
Nutritional and lipidomics biomarkers of docosahexaenoic acid-based multivitamin therapy in pediatric NASH
No full textTwo recent randomized controlled trials demonstrated improved radiographic, histological and hepatometabolic cues of non-alcoholic steatohepatitis (NASH) in pediatric patients treated with the omega-3 fatty acid docosahexaenoic acid (DHA) in combination with vitamin D (VD) or with choline (CHO) and vitamin E (VE), the DHA-VD and DHA-CHO-VE trials, respectively). In the present study we verified the nutritional compliance to these DHA-based multivitamin treatments; lipidomics biomarkers of the reported outcome on NASH indicators were also investigated. Samples were obtained from 30 biopsyproven pediatric NASH patients of the DHA-CHO-VE trial randomized in multivitamin treatment group and placebo group (n = 15 each), and from 12 patients of the treatment group of the DHA-VD trial. All patients underwent 6-month therapy plus 6 months of follow-up. Plasma samples and clinical data were obtained at baseline and at the end of the study (12 months). Selected biomarkers included the free form of DHA and other omega-3 fatty acid arachidonic acid (AA), indices of the vitamin E status, and some hepatic metabolites of these lipids. Radiographic and histological improvements of treated patients were associated with increased concentrations of DHA, alpha-linolenic acid and alpha-tocopherol (i.e. VE), and with decreased AA that was also investigated in complex lipids by untargetd lipidomics. As a result a significantly lowered AA/DHA ratio was observed to represent the main indicator of the response to the DHA-based therapy. Furthermore, baseline levels of AA/DHA showed strong association with NAS and US improvement. A stable correction of DHA AA metabolism interaction is associated with the curative effect of this therapy and may represent a key nutritional endpoint in the clinical management of pediatric NASH
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