Loretta Guidi - Academia.edu (original) (raw)

Papers by Loretta Guidi

Redox biology, Oct 1, 2017

Oxysterols are bioactive lipids that act as regulators of lipid metabolism, inflammation, cell vi... more Oxysterols are bioactive lipids that act as regulators of lipid metabolism, inflammation, cell viability and are involved in several diseases, including atherosclerosis. Mounting evidence linked the atherosclerosis to endothelium dysfunction; in fact, the endothelium regulates the vascular system with roles in processes such as hemostasis, cell cholesterol, hormone trafficking, signal transduction and inflammation. Several papers shed light the ability of oxysterols to induce apoptosis in different cell lines including endothelial cells. Apoptotic endothelial cell and endothelial denudation may constitute a critical step in the transition to plaque erosion and vessel thrombosis, so preventing the endothelial damaged has garnered considerable attention as a novel means of treating atherosclerosis. Endoplasmic reticulum (ER) is the site where the proteins are synthetized and folded and is necessary for most cellular activity; perturbations of ER homeostasis leads to a condition known as endoplasmic reticulum stress. This condition evokes the unfolded protein response (UPR) an adaptive pathway that aims to restore ER homeostasis. Mounting evidence suggests that chronic activation of UPR leads to cell dysfunction and death and recently has been implicated in pathogenesis of endothelial dysfunction. Autophagy is an essential catabolic mechanism that delivers misfolded proteins and damaged organelles to the lysosome for degradation, maintaining basal levels of autophagic activity it is critical for cell survival. Several evidence suggests that persistent ER stress often results in stimulation of autophagic activities, likely as a compensatory mechanism to relieve ER stress and consequently cell death. In this review, we summarize evidence for the effect of oxysterols on endothelial cells, especially focusing on oxysterols-mediated induction of endoplasmic reticulum stress.

International Journal on Magnetic Particle Imaging, Sep 2, 2020

Although Magnetic Particle Imaging (MPI) is not yet in clinical use, it is highly promising for s... more Although Magnetic Particle Imaging (MPI) is not yet in clinical use, it is highly promising for several medical applications, and especially for applications in diagnostic vascular in vivo imaging and imaging-guided vascular interventions. Furthermore, in the last years, different superparamagnetic iron oxide (SPIO) based contrast agents have been developed and approved for niche clinical applications in Magnetic Resonance Imaging (MRI) as alternative to Gadolinium-based contrast agents (GBCAs) due to the risk for patients suffering from kidney dysfunction or nephrogenic systemic fibrosis (NSF). Recently, the potential of RBCs loaded with different SPIO nanoparticles as blood-pool tracer agents with longer blood retention time for MRI and MPI has been investigated. Here, we report the first in vitro results with the highly efficient dextran-based MPI tracer particles perimag ® and synomag ®-D to study their eligibility to be encapsulated into human RBCs and the potential of these new SPIO-RBC constructs as tracer material for MPI.

Journal of Functional Foods, Apr 1, 2020

Plants

By 2030, the European Commission intends to halve chemical pesticide use and its consequent risks... more By 2030, the European Commission intends to halve chemical pesticide use and its consequent risks. Among pesticides, nematicides are chemical agents used to control parasitic roundworms in agriculture. In recent decades, researchers have been looking for more sustainable alternatives with the same effectiveness but a limited impact on the environment and ecosystems. Essential oils (EOs) are similar bioactive compounds and potential substitutes. Different studies on the use of EOs as nematicides are available in the Scopus database in the scientific literature. These works show a wider exploration of EO effects in vitro than in vivo on different nematode populations. Nevertheless, a review of which EOs have been used on different target nematodes, and how, is still not available. The aim of this paper is to explore the extent of EO testing on nematodes and which of them have nematicidal effects (e.g., mortality, effects on motility, inhibition of egg production). Particularly, the re...

Biocatalysis and Agricultural Biotechnology

Free-living marine nematodes are microinvertebrates composing one of the most diversified groups ... more Free-living marine nematodes are microinvertebrates composing one of the most diversified groups of the marine biota, with more than 7000 species. This means that only the 20% of the species is currently known. Several morphological features can help their taxonomical identification such as cephalic, cervical and body setae, amphids, cuticle, spicules and tail that may also have a functional role. Given the small size of these organisms, they differ in minute characters that can be detected more effectively by scanning electron microscopy (SEM). This study presents an overview of the use of SEM on some nematode species collected in the Maldivian archipelago, and highlights the importance of this technique in the taxonomical study of nematodes as well as its potentialities in the functional investigation of some of their structures.

Marine Environmental Research, 2018

The taxonomical structure and diversity of nematode assemblages are the main attributes analyzed ... more The taxonomical structure and diversity of nematode assemblages are the main attributes analyzed in ecology, but nematode adaptations to their habitats are still understudied. Accordingly, a survey on some known and other newly proposed morpho-functional traits was carried out in order to: determine if the morpho-functional diversity of nematodes mirrors their taxonomical diversity; and assess potential nematode adaptations to sediment type and hydrodynamic stress. Morpho-functional traits were investigated both singularly and together and showed significant differences related to these environmental factors. The greatest taxonomical and morphofunctional diversity was found in medium-coarse sand (M-CS) and at an intermedium energy level (IEL). The M-CS and IEL were probably richer in micro-habitats and subject to a low selective pressure, hosting nematodes with a wide range of adaptations. The mirroring of morpho-functional diversity with taxonomical diversity is crucial for the future growth of the use of nematodes in biomonitoring. This is because the study of their morphofunctional traits could reduce the level of work involved and the costs of any analyses.

Water, Oct 1, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

PeerJ

The intensification of dredging and infilling activities in lagoons and on coral reefs are common... more The intensification of dredging and infilling activities in lagoons and on coral reefs are common practices in the Maldivian archipelago, and these activities alter the biodiversity of the bioconstructors and the functioning of the ecosystem. The alteration of environmental factors can also affect inconspicuous fauna, such as free-living nematodes. The implications of a reduction in biodiversity may transcend decreased taxonomic diversity, resulting in changes in functional diversity and redundancy; however, how the environmental conditions and human pressure affects the functionality of nematodes in Maldivian coral degradation zones (CDZs) remain poorly understood. In this paper, we examined changes in the taxonomic and functional diversity and the functional redundancy in nematode communities regarding the geographic location (atolls with various levels of human pressure), the exposure and topography of the reef (lagoon and ocean), the slope of the reef, and the depth. The functio...

Acineta sp. (Figs. 7 a, b) Diagnosis. Marine suctorian cili... more Acineta sp. (Figs. 7 a, b) Diagnosis. Marine suctorian ciliate. Trapezium-like cell body, weakly laterally compressed, thin-walled and wrinkled. Lorica filled with cell body and provided with a dumb-bell shaped apical aperture. Two lobe-like actinophores protruding. Usually tentacles arranged in two fascicles in the apical aperture. Small solid stalk. Reproduction by mono- or polygemmic internal budding. Morphological description. Marine loricate suctorian. Cell body trapezium-like, weakly laterally compressed and fully covered with lorica. Insertion of lorica at the body base. Thin-walled lorica about 52 µm in length and 21 µm in width, ratio of length to width approximately 2:1, maximum width at the upper end (Figs. 7 a–b). Very minute longitudinal rows across the lorica. Apical aperture dumb-bell shaped showing two protruding lobe-like actinophores. Tentacles not visible at the apical region (Figs. 7 a–b). Very small solid stalk, slightly apically extended. Stalk length 3 µm and thickness 1µm. The usually monogemmic or polygemmic internal budding and swarmers were not observed. Remarks. The studied specimen of Acineta sp. was similar to the type species Acineta tuberosa Ehrenberg, 1834 due to the Y-shaped outline and the stalk joining lorica without any basal disc but differed in the stalk length and the basibionts. On other side, it also showed similarity with Acineta laevis Dons, 1918 from red algae, with body fully covered by lorica and permanently contracted tentacles. However Acineta sp. differs from A. laevis by a relatively thin stalk, 1 µm, vs. 8 µm (see Curds 1985). Host specificity and locality information. Acineta sp. adhered to a free-living marine nematode species, Croconema cinctum, and it was collected from sediments mainly characterized by sand (93%), followed by gravel (5%) and mud (3%) at a depth of 61 m (S1 station).

Limnoricus ceter Jankowski, 1981 (Figs. 6 b–c) Dia... more Limnoricus ceter Jankowski, 1981 (Figs. 6 b–c) Diagnosis. Marine loricate suctorian. Cell body and lorica sharply flattened laterally. Cell body attached to the margin of lorica aperture that is surrounded by collar-like borders. Contractile, clavate tentacles arranged in apical rows. Long straight stalk (pseudostyle) present. Macronucleus ellipsoidal. Reproduction generally by regular exogemmic, semicircumvaginative, budding. Morphological description. Laterally flattened marine loricate ciliate. The cell of the body fills two-thirds of lorica that measured 34–60 µm in length and 12–56 µm in width (Figs. 6 b and 6c). Cell body from 13 to 42 µm in length and from 9 to 37 µm width. Rows of contractile, clavate tentacles arranged in the apical aperture. Ellipsoidal macronucleus was observed in the middle of the cell body (Fig. 6 c). Micronuclei not observed. Long, straight and enlarged stalk attached the lorica base of the suctorian to the host. Stalk length varied from 6 to 46 µm and thickness from 1 to 4 µm (Fig. 6 b). The swarmer was not observed. Remarks. The observed specimens of L. ceter differed from earlier observations in body size and host specificity. Indeed, they were smaller than those earlier reported (Jankowski 1981): their lorica length and width were two third than those originally described, and the stalk one a fourth of the total stalk length (see Dovgal et al. 2008b). Furthermore, the holotype specimen was reported from marine isopods (Jankowski 1981), whereas the specimens documented in this study were found on a harpacticoid copepod and for the first time on a nematode of the genus Desmodora de Man, 1889. Host specificity and locality information. L. ceter was first described by Jankowski (1981), attached to marine isopods from the Sakhalin and Kunashyr Islands, and then also from halacarid mites from Barents Sea (Jankowski 1981). The present specimens were found at S2 and S4 stations of the Suvadiva atoll lagoon at a depth [...]

Thecacineta calix (Schröder, 1907) (Figs. 5 a–d) Diagnosis.... more Thecacineta calix (Schröder, 1907) (Figs. 5 a–d) Diagnosis. Marine loricate suctorian. Lorica filled with cell body, transversely ribbed and attached to its base. A fascicle of clavate tentacles in apical surface of body. Macronucleus ovoid with large contractile vacuole. Long and curved stalk with apical widening. Reproduction by vermigemmic budding. Morphological description. Marine. Cell body fully filling the lorica and attached to its base. Lorica size 50– 81 µm × 22–34 µm, ratio of length to width approximately 2:1, maximum width at the middle (Figs. 5 a–d). Whole lorica characterized with several annular ridges variable in number from 13 to 24 (Figs. 5 a–c). Apical surface of the body bearing a fascicle of clavate tentacles, 10–14 µm in length and 1 µm in thickness (Figs. 5 a and 5c). Macronucleus and micronuclei not observed. Stalk long, thin and curved with apical widening (physon) and base attaching to the host. Stalk 10–17 µm in length and 2.1–2.2 µm in thickness (Figs. 5 a–d). Reproduction by vermigemmic budding with formation of laterally vermiform protomit (Fig. 5 d). Swarmer without annular ridges or tentacles. Remarks. The observed specimens of Thecacineta calix (Schröder, 1907) differ from those earlier reported by a larger variation in the number of ribbed transverse annular ridges. In the observed specimens the transversely annulated ribs varied from 9 to 26 throughout the body (see Fig. 5 a,b,c). Moreover, the present specimens were two-fold smaller than that found in Mediterranean Sea, which was attached to the harpacticoid copepod Laophonte cornuta (Matthes, 1956). They were particularly comparable with those reported by Chatterjee et al. (2014) from Caribbean reef ecosystem. Host specificity and locality information. T. calix (Schröder 1907) is well known as a widespread suctorian ciliate attached to numerous groups of interstitial invertebrates such as nematodes and halacarid mites. In particular, it is frequent on the n [...]

Thecacineta urceolata Liao & Dovgal, 2015 (Fig. 6 a) Diagnosi... more Thecacineta urceolata Liao & Dovgal, 2015 (Fig. 6 a) Diagnosis. Marine suctorian ciliate. Cell body attached at the bottom of the lorica. Narrow apical end protruding from lorica aperture. Smooth lorica ridged at its aperture. A bundle of capitate tentacles placed apically. Macronucleous spherical. Long and curved stalk with apical widening. Reproduction by vermigemmic budding. Morphological description. Marine loricate suctorian. Cell body narrowed towards the apical end. Body 70 µm in length and 19 µm in width. Smooth lorica larger than the cell body, about 84 µm in length and 42 µm in width with a ratio of ca. 2:1. Annular ridge, not well pronounced, in the lorica aperture that narrowed from body to apical end with its specific urceolate structure clearly visible (Fig. 6 a). A bundle of tentacles in the apical part of body, about 10–15 µm in length and 1 µm in thickness. Macronucleus spherical almost equal in length and width and located just above the base of the body (Fig. 6 a). Long, thin and curved stalk 75 µm in length and 7 µm in thickness. Reproduction usually by vermigemmic budding with formation of laterally vermiform protomit, but swarmer not observed in the present samples. Remarks. The observed specimen of T. urceolata Liao & Dovgal, 2015 differs from those earlier observed by the lorica and stalk size. It showed a larger lorica size as well as a stalk twice in length compared to the earlier report (holotype—Liao & Dovgal, 2015). Moreover, the observed specimen had no cuticular transverse ribs as the morphologically close species Praethecacineta halacari Schulz, 1933 that was reported on Copidognathus sp. from He-Ping-Dao (Dovgal et al. 2009b). P. halacari Schulz, 1933 is characterized by the semi-circumvaginative exogemmic budding with formation of lateral ciliate protomit, which differs from the vermigemmic budding of T. urceolata. Host specificity and locality information. T. urceolata was first descr [...]

Diversity, 2020

Epibiosis is a common phenomenon in marine systems. In marine environments, ciliates are among th... more Epibiosis is a common phenomenon in marine systems. In marine environments, ciliates are among the most common organisms adopting an epibiotic habitus and nematodes have been frequently reported as their basibionts. In the present study, we report several new records of peritrich and suctorian ciliates-nematode association worldwide: from a deep-sea pockmark field in the NW Madagascar margin (Indian Ocean), from a shallow vent area in the Gulf of Naples (Mediterranean, Tyrrhenian Sea), in a MPA area in the Gulf of Trieste (Mediterranean, Adriatic Sea), from a mangrove system in French Guiana (South America, Atlantic Ocean), and from the Maldivian Archipelago. In addition, three new species of Suctorea from the Secca delle Fumose shallow vent area (Gulf of Naples) were described: Loricophrya susannae n. sp., Thecacineta fumosae n. sp. and Acinetopsis lynni n. sp. In the light of these new records and data from the existing literature, we discuss the suctorian–nematode epibiosis relat...

PeerJ, 2019

The aim of this work was to test and analyse the bioeffects of Prunus spinosa L. (Rosacaee) fruit... more The aim of this work was to test and analyse the bioeffects of Prunus spinosa L. (Rosacaee) fruit ethanol extract on Trichoplax adhaerens Schulze, 1883 (Placozoa) laboratory cultures which—for the first time—were employed as in vivo biological model to assess the bioactivity of a natural extract. The ethanol extract of P. spinosa was administrated during a 46 day experimental period; ultrastructural (by optical, confocal, TEM and SEM microscopy) and morphometric analyses indicated that treated Trichoplax adhaerens showed significant differences in viability, reproductive modalities, body shape and colour with respect to the control group. Finally, P. spinosa bioactive compounds seem to exert profound protective effects on T. adhaerens reproduction and phenotype. Our results may support additional investigations related to other bioactive compounds properties useful for nutraceutical preparations to be used as food supplements.

Systematics and Biodiversity, 2016

Most studies of South American freshwater Gastrotricha have focused on the inland waters of Brazi... more Most studies of South American freshwater Gastrotricha have focused on the inland waters of Brazil including São Paulo State, Mato Grosso do Sul State, and Par a State. In this paper, we describe a new genus and species, Cephalionotus kisielewskii gen. et. sp. nov. (Chaetonotida, Chaetonotidae), from Minas Gerais State using morphological data and DNA sequence data (18S rDNA and COI genes). The new genus contains a single psammic species collected from high altitude streams. Cephalionotus gen. nov. exhibits a set of autapomorphic characters that easily distinguish it from all other genera of Chaetonotida: extremely large cephalion and hypostomium that completely cover the dorsal and ventral sides of the head, respectively; a single pair of pleurae; peculiar shape and arrangement of dorsal and ventral scales in the posterior trunk region; one paired, very large, keeled scale at the ventral posterior end; and very long adhesive tubes divided into three parts. Affinity of Cephalionotus kisielewskii gen. et sp. nov. with other Chaetonotida (Paucitubulatina) is discussed from morphological and molecular perspectives.

Zootaxa, 2017

Five species of suctorian ciliates belonging to four different genera attached to meiofaunal orga... more Five species of suctorian ciliates belonging to four different genera attached to meiofaunal organisms of Maldivian archipelago (Suvadiva Atoll) were documented. Three rare species (Acineta sp., Thecacineta urceolata Liao & Dovgal, 2015 and Limnoricus ceter Jankowski, 1981) and one common suctorian ciliate Thecacineta calix (Schröder, 1907) are re-described from nematodes (Croconema cinctum Cobb, 1920, Desmodorella tenuispiculum Allgén, 1928 and Desmodora sp.) and harpacticoid copepod basibionts. In addition, Trophogemma colantonii n. sp. colonizing the abdomen and legs of the harpacticoid copepod Stenhelia sp. is described. The new species differs from the relative species for the less flattened cell body, the absence of both lateral bundles of tentacles and separate lateral tentacles as well as for the presence of longitudinal ribs along the cuticle. The data obtained in this survey give not only new important information on the taxonomy and distribution of Suctorea, but also new ...

Bulletin De La Societe Zoologique De France, 2010

La position phylogenetique des Gastrotricha, l'un des groupes le plus restreints et des moins... more La position phylogenetique des Gastrotricha, l'un des groupes le plus restreints et des moins bien connus des Bilateria, est encore en discussion. En fait, durant les dernieres decennies, cet embranchement, originellement inclus dans l'ensemble heterogene des « Aschelminthes », en particulier considere tres proches des Rotifera et des Nematoda, a fait l'objet d'un interet phylogenetique croissant. De nombreuses etudes morphologiques et ultrastructurales ont conduit a reconsiderer les relations de ce phylum en soutenant l'hypothese qu'il constituerait le groupe-frere des Cyclioneuralia ou des Ecdysozoa. Par ailleurs, les analyses moleculaires recentes (gene 18S rRNA) ont suggere l'insertion des Gastrotricha dans les Platyzoa, en soulignant leurs affinites avec les Gnathostomulida et les organismes acelomates. Aussi les relations a l'interieur du groupe ont-elles ete etudiees de maniere approfondie sur des bases aussi bien morphologiques que moleculaire...

Nanomaterials

Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inf... more Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inflammatory activities. Innovative drug delivery systems such as biomimetic nanoparticles could improve the activity of PSF extract by promoting (i) the protection of payload into the lipidic bilayer, (ii) increased accumulation to the diseased tissue due to specific targeting properties, (iii) improved biocompatibility, (iv) low toxicity and increased bioavailability. Using membrane proteins extracted from human monocyte cell line THP-1 cells and a mixture of phospholipids, we formulated two types of PSF-extract-loaded biomimetic vesicles differing from each other for the presence of either 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (DOPG). The biological activity of free extract (PSF), compared to both types of extract-loaded vesicles (PSF-DOPCs and PSF-DOPGs) and empty vesicles (DOPCs and DOPGs), was evaluated in vitro on HUVEC...