160 research outputs found

    Recruitment of Oysters by Different Collection Devices at a Longline shellfish Farm in the Central Adriatic Sea

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    In 2020–2021, a trial to recruit flat oysters was implemented at a longline farm in the central Adriatic, whereby the efficiency recruitment (n. oyster/dm2) of different suspended substrates was evaluated. Two lantern nets (50 cm diameter; 145 cm h) had different substrates composed of 8 mm wide wrinkled ribbon and empty oyster shells positioned in the upper levels of the lanterns. The tumbling evaluation and the presence of mud were also considered. The efficiency recruitment was similar between the wrinkled ribbon and the oyster shell. Recruitment was in the same proportion on the external rough part of the shells as on the internal smooth part of the shells. No significant differences were shown when comparing the different substrates in terms of recruitment efficiency

    Effects of Diisodecyl Phthalate on PPAR:RXR-Dependent Expression Pathways in Sea Bream Hepatocytes

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    Evidence that endocrine-disrupting chemicals (EDCs) may target metabolic disturbances, beyond interference with the functions of the endocrine systems has recently accumulated. Among EDCs, phthalate plasticizers like the diisodecyl phthalate (DiDP) are commonly found contaminants of aquatic environments and have been suggested to function as obesogens by activating peroxisome proliferator activated receptors (PPARs), a subset of nuclear receptors (NRs) that act as metabolic sensors, playing pivotal roles in lipid homeostasis. However, little is known about the modulation of PPAR signaling pathways by DiDP in fish. In this study, we have first investigated the ligand binding efficiency of DiDP to the ligand binding domains of PPARs and retinoid-X-receptor-α (RXRα) proteins in fish using a molecular docking approach. Furthermore, in silico predictions were integrated by in vitro experiments to show possible dose-relationship effects of DiDP on PPAR:RXR-dependent gene expression pathways using sea bream hepatocytes. We observed that DiDP shows high binding efficiency with piscine PPARs demonstrating a greater preference for RXRα. Our studies also demonstrated the coordinate increased expression of PPARs and RXRα, as well as their downstream target genes in vitro. Principal component analysis (PCA) showed the strength of relationship between transcription of most genes involved in fatty acid metabolism and PPAR mRNA levels. In particular, fatty acid binding protein (FABP) was highly correlated to all PPARs. The results of this study suggest that DiDP can be considered an environmental stressor that activates PPAR:RXR signaling to promote long-term changes in lipid homeostasis leading to potential deleterious physiological consequences in teleost fish

    Folding-upon-Repair DNA Nanoswitches for Monitoring the Activity of DNA Repair Enzymes

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    We present a new class of DNA-based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding-upon-repair DNA nanoswitches are synthetic DNA sequences containing O6 -methyl-guanine (O6 -MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation of the O6 -MeG nucleobases they can form stable intramolecular Hoogsteen interactions and fold into an optically active triplex DNA structure. We have first characterized the folding mechanism induced by the enzymatic repair activity through fluorescent experiments and Molecular Dynamics simulations. We then demonstrated that the folding-upon-repair DNA nanoswitches are suitable and specific substrates for different methyltransferase enzymes including the human homologue (hMGMT) and they allow the screening of novel potential methyltransferase inhibitors

    Ghrelin induces apoptosis in colon adenocarcinoma cells via proteasome inhibition and autophagy induction.

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    Ghrelin is a metabolism-regulating hormone recently investigated for its role in cancer survival and progression. Controversially, ghrelin may act as either anti-apoptotic or pro-apoptotic factor in different cancer cells, suggesting that the effects are cell type dependent. Limited data are currently available on the effects exerted by ghrelin on intracellular proteolytic pathways in cancer. Both the lysosomal and the proteasomal systems are fundamental in cellular proliferation and apoptosis regulation. With the aim of exploring if the proteasome and autophagy may be possible targets of ghrelin in cancer, we exposed human colorectal adenocarcinoma cells to ghrelin. Preliminary in vitro fluorimetric assays evidenced for the first time a direct inhibition of 20S proteasomes by ghrelin, particularly evident for the trypsin-like activity. Moreover, 1 μM ghrelin induced apoptosis in colorectal adenocarcinoma cells by inhibiting the ubiquitin-proteasome system and by activating autophagy, with p53 having an "interactive" role

    Plasticizers used in food-contact materials affect adipogenesis in 3T3-L1 cells

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    Recent studies suggest that exposure to some plasticizers, such as Bisphenol A (BPA), play a role in endocrine/metabolic dispruption and can affect lipid accumulation in adipocytes. Here, we investigated the adipogenic activity and nuclear receptor interactions of four plasticizers approved for the manufacturing of food-contact materials (FCMs) and currently considered safer alternatives. Differentiating 3T3-L1 mouse preadipocytes were exposed to scalar concentrations (0.01-25 μM) of DiNP (Di-iso-nonyl-phthalate), DiDP (Di-iso-decyl-phthalate), DEGDB (Diethylene glycol dibenzoate), or TMCP (Tri-m-cresyl phosphate). Rosiglitazone, a well-known pro-adipogenic peroxisome proliferator activated receptor gamma (PPARγ) agonist, and the plasticizer BPA were included as reference compounds. All concentrations of plasticizers were able to enhance lipid accumulation, with TMCP being the most effective one. Accordingly, when comparing in silico the ligand binding efficiencies to the nuclear receptors PPARγ and retinoid-X-receptor-alpha (RXRα), TMPC displayed the highest affinity to both receptors. Differently from BPA, the four plasticizers were most effective in enhancing lipid accumulation when added in the mid-late phase of differentiation, thus suggesting the involvement of different intracellular signalling pathways. In line with this, TMCP, DiDP, DiNP and DEGDB were able to activate PPARγ in transient transfection assays, while previous studies demonstrated that BPA acts mainly through other nuclear receptors. qRT-PCR studies showed that all plasticizers were able to increase the expression of CCAAT/enhancer binding protein β (Cebpβ) in the early steps of adipogenesis, and the adipogenesis master gene Pparγ2 in the middle phase, with very similar efficacy to that of Rosiglitazone. In addition, TMCP was able to modulate the expression of both Fatty Acid Binding Protein 4/Adipocyte Protein 2 (Fabp4/Ap2) and Lipoprotein Lipase (Lpl) transcripts in the late phase of adipogenesis. DEGDB increased the expression of Lpl only, while the phthalate DiDP did not change the expression of either late-phase marker genes Fabp4 and Lpl. Taken together, our results suggest that exposure to low, environmentally relevant doses of the plasticizers DiNP, DiDP, DEGDB and TMCP increase lipid accumulation in 3T3-L1 adipocytes, an effect likely mediated through activation of PPARγ and interference at different levels with the transcriptional cascade driving adipogenesis

    Ventricular arrhythmias in young competitive athletes: Prevalence, determinants, and underlying substrate

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    Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes.Background--Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes. Method and Results--We studied 288 competitive athletes (age range, 16-35 years; median age, 21 years) and 144 sedentary individuals matched for age and sex who underwent 12-lead 24-hour ambulatory electrocardiographic monitoring. VAs were evaluated in terms of number, complexity (ie, couplet, triplet, or nonsustained ventricular tachycardia), exercise inducibility, and morphologic features. Twenty-eight athletes (10%) and 13 sedentary individuals (11%) showed > 10 isolated premature ventricular beats (PVBs) or 651 complex VA (P=0.81). Athletes with > 10 isolated PVBs or 651 complex VA were older (median age, 26 versus 20 years; P=0.008) but did not differ with regard to type of sport, hours of training, and years of activity compared with the remaining athletes. All athletes with > 10 isolated PVBs or 651 complex VA had a normal echocardiographic examination; 17 of them showing > 500 isolated PVBs, exercise-induced PVBs, and/or complex VA underwent additional cardiac magnetic resonance, which demonstrated nonischemic left ventricular late gadolinium enhancement in 3 athletes with right bundle branch block PVBs morphologic features. Conclusions--The prevalence of > 10 isolated PVBs or 651 complex VA at 24-hour ambulatory electrocardiographic monitoring did not differ between young competitive athletes and sedentary individuals and was unrelated to type, intensity, and years of sports practice. An underlying myocardial substrate was uncommon and distinctively associated with right bundle branch block VA morphologic features

    Core-shell graphene oxide-polymer hollow fibers as water filters with enhanced performance and selectivity

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    Commercial hollow fiber filters for micro- and ultrafiltration are based on size exclusion and do not allow the removal of small molecules such as antibiotics. Here, we demonstrate that a graphene oxide (GO) layer can be firmly immobilized either inside or outside polyethersulfone-polyvinylpyrrolidone hollow fiber (Versatile PES (R), hereafter PES) modules and that the resulting core-shell fibers inherits the microfiltration ability of the pristine PES fibers and the adsorption selectivity of GO. GO nanosheets were deposited on the fiber surface by filtration of a GO suspension through a PES cartridge (cut-off 0.1-0.2 mu m), then fixed by thermal annealing at 80 degrees C, rendering the GO coating stably fixed and unsoluble. The filtration cut-off, retention selectivity and efficiency of the resulting inner and outer modified hollow fibers (HF-GO) were tested by performing filtration on water and bovine plasma spiked with bovine serum albumin (BSA, 66 kDa, approximate to 15 nm size), monodisperse polystyrene nanoparticles (52 nm and 303 nm sizes), with two quinolonic antibiotics (ciprofloxacin and ofloxacin) and rhodamine B (RhB). These tests showed that the microfiltration capability of PES was retained by HF-GO, and in addition the GO coating can capture the molecular contaminants while letting through BSA and smaller polystyrene nanoparticles. Combined XRD, molecular modelling and adsorption experiments show that the separation mechanism does not rely only on physical size exclusion, but involves intercalation of solute molecules between the GO layers

    Graphene Oxide Promotes Site-Selective Allylic Alkylation of Thiophenes with Alcohols

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    The graphene oxide (GO) assisted allylic alkylation of thiophenes with alcohols is presented. Mild reaction conditions and a low GO loading enabled the isolation of a range of densely functionalized thienyl and bithienyl compounds in moderate to high yields (up to 90%). The cooperative action of the Bronsted acidity, epoxide moieties, and pi-surface of the 2D-promoter is highlighted as crucial in the reaction course of the present Friedel-Crafts-type protocol
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