Giordano Francesco M.

No Thumbnail Available
Last Name
Giordano
First Name
Francesco M.
ORCID

Filters

2015 - 2016 2
2
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Article
    Effects of lead pollution on Ammonia parkinsoniana (foraminifera) : ultrastructural and microanalytical approaches
    (PAGEPress, 2015-01-30) Frontalini, Fabrizio ; Curzi, Davide ; Giordano, Francesco M. ; Bernhard, Joan M. ; Falcieri, E. ; Coccioni, Rodolfo
    The responses of Ammonia parkinsoniana (Foraminifera) exposed to different concentrations of lead (Pb) were evaluated at the cytological level. Foraminifera-bearing sediments were placed in mesocosms that were housed in aquaria each with seawater of a different lead concentration. On the basis of transmission electron microscopy and environmental scanning electron microscopy coupled with energy dispersive spectrometer analyses, it was possible to recognize numerous morphological differences between untreated (i.e., control) and treated (i.e., lead enrichment) specimens. In particular, higher concentrations of this pollutant led to numerical increase of lipid droplets characterized by a more electron-dense core, proliferation of residual bodies, a thickening of the organic lining, mitochondrial degeneration, autophagosome proliferation and the development of inorganic aggregates. All these cytological modifications might be related to the pollutant-induced stress and some of them such as the thickening of organic lining might suggest a potential mechanism of protection adopted by foraminifera.
  • Article
    Mercury-pollution induction of intracellular lipid accumulation and lysosomal compartment amplification in the benthic foraminifer Ammonia parkinsoniana
    (Public Library of Science, 2016-09-07) Frontalini, Fabrizio ; Curzi, Davide ; Canonico, Barbara ; Giordano, Francesco M. ; De Matteis, Rita ; Bernhard, Joan M. ; Pieretti, Nadia ; Gu, Baohua ; Eskelsen, Jeremy ; Jubb, Aaron ; Zhao, Linduo ; Pierce, Eric M. ; Gobbi, Pietro ; Papa, Stefano ; Coccioni, Rodolfo
    Heavy metals such as mercury (Hg) pose a significant health hazard through bioaccumulation and biomagnification. By penetrating cell membranes, heavy metal ions may lead to pathological conditions. Here we examined the responses of Ammonia parkinsoniana, a benthic foraminiferan, to different concentrations of Hg in the artificial sea water. Confocal images of untreated and treated specimens using fluorescent probes (Nile Red and Acridine Orange) provided an opportunity for visualizing the intracellular lipid accumulation and acidic compartment regulation. With increased Hg over time, we observed an increased number of lipid droplets, which may have acted as a detoxifying organelle where Hg is sequestered and biologically inactivated. Further, Hg seems to promote the proliferation of lysosomes both in terms of number and dimension that, at the highest level of Hg, resulted in cell death. We report, for the first time, the presence of Hg within the foraminiferal cell: at the basal part of pores, in the organic linings of the foramen/septa, and as cytoplasmic accumulations.