Luisa Giari - Academia.edu (original) (raw)

Papers by Luisa Giari

Ecological Indicators, Oct 1, 2017

Abstract An operator-neutral, objective method was implemented to comparatively assess liver path... more Abstract An operator-neutral, objective method was implemented to comparatively assess liver pathology in 30 specimens of common carp (Cyprinus carpio): 20 after experimental flow-through exposure to two perfluorooctanoic acid (PFOA) dosages (10 fish exposed to 200 ng l−1 and 10 fish exposed to 2 mg l−1) for 56 days and 10 unexposed (negative control). The method relies on texture analysis as a complementary approach to traditional histopathology and chemical dosage analysis performed previously on the same experimental material. Texture features data were analyzed by means of Redundancy Analysis (RDA), Linear Discriminant Analysis (LDA) and Canonical Variates Analysis (CVA). LDA resulted in the correct classification of 80% of cases (24 out of 30 cases) with a sensitivity of 83.3% and a specificity of 83.3. In particular, four male samples from the low dosage group (200 ng l−1) were misclassified as unexposed fish and two female samples from the unexposed group were misclassified as low dosage exposed. Nevertheless, PFOA liver chemical dosage analysis results were the same both in unexposed and in low dosage group fish, all below the limit of detection. No sample from the high dosage group (2 mg l−1) has ever been misclassified. Interestingly, texture features correlated with the PFOA concentrations detected in the liver of each sampled fish. In the present study the technique of texture analysis was combined with techniques of multivariate exploratory data analysis (RDA, LDA/CVA). This approach resulted in a robust, sufficiently sensitive and specific means to study PFOA-induced liver pathology. The new method can discriminate between unexposed and two PFOA exposed groups with better confidence and in a more affordable way, compared to chemical quantification of liver PFOA. The texture features correlated well with liver PFOA concentrations and objectively quantified degenerative liver morphology. In conclusion the overall approach may be a suitable candidate as a reliable and broad-ranging method for biomarker analysis of exposure and effect.

Ecotoxicology and Environmental Safety, Apr 1, 2022

Per- and poly-fluoroalkyl substances (PFAS) are synthetic contaminants of global concern for envi... more Per- and poly-fluoroalkyl substances (PFAS) are synthetic contaminants of global concern for environmental and public health. Perfluorooctanoic acid (PFOA) is an important PFAS, and considerable attention has been paid to its hepatotoxicity and reproductive and developmental impact, while potential nephrotoxic effects are largely ignored, especially in fish. This study documents the structural and ultrastructural effects on kidney of common carp Cyprinus carpio exposed to waterborne PFOA at an environmentally relevant concentration of 200 ng L-1 and at 2 mg L-1. Dilation of the glomeruli capillary bed, increased vesiculation in the proximal tubular segment, compromised mitochondria, apical blebbing, and sloughing of collecting duct cells occurred in exposed fish, primarily at 2 mg L-1. Perfluorooctanoic acid exposure resulted in higher numbers of rodlet cells (RC), putative immune cells exclusive to fish, mainly in the renal interstitium, than seen in controls, increased association with cells of myeloid lineage and modifications to ultrastructure. No differences in other cells of innate immunity were observed. Despite the absence of severe histological lesions, PFOA was shown to affect both nephron and hemopoietic interstitium at high concentration, raising concern of the impact on renal and immune function in fish. The response of RCs to PFOA concentration of 200 ng L-1 suggests a potential role as a biomarker of PFOA exposure.

Parasites & Vectors, Jul 16, 2018

Microscopy Research and Technique, 2008

Scanning electron microscope (SEM) investigations on the holdfast elements, proboscis hooks, and ... more Scanning electron microscope (SEM) investigations on the holdfast elements, proboscis hooks, and trunk spines of Dentitruncus truttae (Acanthocephala, Palaeacanthocephala), an endoparasite of Salmo trutta (brown trout), provide more data about the surface of these taxonomic relevant structures. In both acanthocephalan sexes, the fully everted cylindrical proboscis possessed 18 longitudinal rows of hooks with 18 hooks per row (rarely 19–20). Hook length varied according to position on the proboscis; apical hooks were 40–52 μm long, middle hooks were 31.7–36.6 μm, and basal hooks were 38.1–40 μm. Starting from the anterior end of the metasoma, numerous cuticular spines (26.7–30 μm in length) were visible and their number progressively decreased posteriorly. SEM observations of D. truttae hooks and spines revealed the presence of many surface striations on each proboscis hook. These surface striations were absent from trunk spines. From the base of the hook, the striations ran parallel toward the point of convergence. Additionally, survey of longitudinal and transversal sections of the hook using transmission electron microscope confirmed that the hook surface was not smooth. SEM comparison with the hooks of several palaeacanthocephalan species, as well as with the hooks of species belonging to Eoacanthocephala and Polyacanthocephala, indicated that the striations are currently exclusive to D. truttae proboscis hooks. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.

Parasites & Vectors, Jul 8, 2015

Fish & Shellfish Immunology, Mar 1, 2016

Environmental Toxicology and Pharmacology, 2021

International Journal of Environmental Research and Public Health, Mar 24, 2023

Diseases of Aquatic Organisms, Mar 29, 2007

Gymnotus inaequilabiatus is a fish of great importance in Pantanal region (Brazil). It is used as... more Gymnotus inaequilabiatus is a fish of great importance in Pantanal region (Brazil). It is used as livebait for collecting other fish species of commercial value and is one of the preferred prey for Caiman yacare. G. inaequilabiatus is paratenic host for the nematode Brevimulticaecum sp. and C. yacari is the definitive host where the adult parasites can be find in the intestine. In two occasions, one in the flood season and one in the dry period, ββ specimens of G. inaequilabiatus were sampled (mean total length ± standard deviation, SD: γ1.88 ± β.54 cm). Larvae of Brevimulticaecum sp. were encountered in likely all the visceral organs, but, this investigation was focused on liver. Twenty-one livers (95%) harboured Brevimulticaecum sp. larvae, with an intensity of infection ranging from 4 to γ4γ larvae (mean ± SD: 71.00±9γ.β8 larvae for liver). In livers with high number of nematode larvae the vast majority of the hepatic tissue was occupied by the parasites. Most Brevimulticaecum sp. larvae were encapsulated on the surface of the liver, enclosed by a granulomatous response involving the peritoneal visceral serosa. The cellular immune response within liver was assessed by histological methods and transmission electron microscopy. The wall of the capsule was composed of two layers: the innermost, which was adjacent to the nematode, consisted of host connective tissue, mainly collagenous fibres, whilst the outer layer consisted mainly of mast cells (MCs) and macrophage aggregates (MAs). In infected livers, hepatocytes, notably those in close proximity to larvae, showed degenerative changes, i.e. swelling and hydropic degeneration. By comparison, hepatocytes in uninfected liver or in regions away from the larvae appeared normal. Emphasis will be placed on the role of MCs and MAs as important components of the host’s inflammatory response

Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, Mar 1, 2009

Scanning and transmission electron microscopic observations were made on the anterior and posteri... more Scanning and transmission electron microscopic observations were made on the anterior and posterior lateral line system of larvae of the blind cavefish, Phreatichthys andruzzii. The investigations were conducted on 36 specimens belonging to three different ages of juvenile: 7, 14, and 28 days posthatching. The basic sensory unit of the mechanoreceptive system is a superficial “neuromast,” which is composed of sensory hair cells (HCs) embedded in nonsensory support cells (SCs) frequently covered with a cupula. Head neuromasts had the longest cupulae. These organs presented the same structure and ultrastructure in the head and along the body of all specimens of P. andruzzii of different ages. Hair cells of neuromasts of P. andruzzii larvae were pear‐shaped cells ∼10–20 μm high and 3–5 μm in diameter. The nucleus of each hair cell was large and basally placed, the cytoplasm contained numerous mitochondria and each HC had a single long kinocilium and several short stereocilia. The majority of SCs were elongated in shape and their nuclei occupied a significant portion of the cytoplasm. The support cells at the margin of the neuromast were particularly thin. Both types of support cells possessed well‐developed rough endoplasmic reticulum and Golgi apparatus. The size and number of neuromasts and their component cells increased with the age of larvae (ANOVA, P < 0.05). The dimensions of the neuromasts of the anterior lateral line (head) did not differ significantly from those of the posterior lateral line (trunk) (ANOVA, P > 0.05). Anat Rec, 292:423–430, 2009. © 2009 Wiley‐Liss, Inc.