Melanomacrophage response and hepatic histopathologic biomarkers in the guppy Poecilia reticulata exposed to iron oxide (maghemite) nanoparticles

Distribution and behavior of lipid droplets in hepatic cells analyzed by variations of citochemical technique and scanning electron microscopy

“…Given the relevance of understanding the toxicity of substances and mixtures, researchers in the field seek biomarkers approach to understand the relationship between the complexity of the interaction of contaminants with the organism. Thus, in the extensive set of biomarkers, assessing oxidative stress involving processes of lipid peroxidation and accumulation of lipids in fish has ground because it reflects aspects of animal health related to the effects of food and water exposed to environmental contamination [1] , [2] , [3] , [4] , why lipid droplet formation is immediately related to the activation of defence mechanisms and reversal of oxidative stress [5 , 6] . In this sense, this methodological proposal brings: (1) an improvement in the lipid marking techniques with osmium, already described in previous works [7 , 8] ; and (2) a new proposal for analyzing the organization of lipid droplets in fish liver, using light microscopy and elementary analysis interface of scanning electron microscopy.…”

Co‐exposure of iron oxide nanoparticles and glyphosate‐based herbicide promote liver toxicity in guppy (Poecilia reticulata): A histochemical and ultrastructural approach

“…For each type of tissue response (inflammatory, circulatory, regressive, and progressive responses), histopathological indices were determined according to the formula for each reason pattern: IH RP = ∑ WjOj RP , and for total histopathological index IH = ∑ IH described by Bernet et al (1999) 34 in which, IH RP , index of each histopathological condition; IH, total histopathological index Wj = relative weight of each condition; Oj, frequency variable being 0: absent; 1: infrequent; 2: frequent; 3: very frequent. The weight of each condition was established according to adaptations of the study by Costa et al (2009), 35 Qualhato et al (2018) 22 and has modifications according to Table 1.…”

“…In this regard, nanotechnology is allied to environmental remediation in studies that proposes to utilize magnetic properties of metallic nanoparticles (NPs), as for example iron oxide NPs (IONPs) 11 to aid in the removal of contaminants from water 12–14 that may be discharged through effluent 15 or other environments 16 . Although the use of IONPs in glyphosate remediation is framed as promising, 17–19 the exposure time and concentration used must be considered, as these are relevant factors that influence the metabolic responses of fish exposed to NPs 20–22 …”

Characterization of histopathological and ultrastructural changes in Myxocyprinus asiaticus acutely infected with virulent Aeromonas hydrophila

“…The results from each observation were then combined for the overall results. For this purpose, several histomorphometric parameters (Qualhato et al, 2018) were estimated: (1) area of MMC (μm 2 ); (2) ratio between MMC area and total visible area; and (3) number of MMCs per total visual area. In addition, the mean prevalence of histological alteration was categorized (Sun et al, 2018) as none (0, =0% of the microscope field), mild (1, <25% of the microscope field), moderate (2, 25%–50% of the microscope field) and severe (3, >50% of the microscope field).…”