Polystyrene nanoplastics as an ecotoxicological hazard: Cellular and transcriptomic evidences on marine and freshwater in vitro teleost models

The contamination of marine and freshwater environments by nanoplastics is considered a global threat for aquatic biota. Taking into account the most recent concentration range estimates reported globally and recognizing a knowledge gap in polystyrene nanoplastics (PS-NPs) ecotoxicology, the present work investigated the harmful effects of 20 nm and 80 nm PS-NPs, at increasing biological complexity, on the rainbow trout Oncorhynchus mykiss RTG-2 and gilthead seabream Sparus aurata SAF-1 cell lines. Twenty nm PS-NPs exerted a greater cytotoxicity than 80 nm ones and SAF-1 were approximately 4-fold more vulnerable to PS-NPs than RTG-2. The engagement of PS-NPs with plasma membranes was accompanied by discernible uptake patterns and morphological alterations along with a nuclear translocation already within a 30-min exposure. Cells were structurally damaged only by the 20 nm PS-NPs in a time-dependent manner as indicated by distinctive features of the execution phase of the apoptotic cell death mechanism such as cell shrinkage, plasma membrane blebbing, translocation of phosphatidylserine to the outer leaflet of the cell membrane and DNA fragmentation. At last, functional analyses unveiled marked transcriptional impairment at both sublethal and lethal doses of 20 nm PS-NPs, with the latter impacting the "Steroid biosynthesis", "TGF-beta signaling pathway", "ECM-receptor interaction", "Focal adhesion", "Regulation of actin cytoskeleton" and "Protein processing in endoplasmic reticulum" pathways. Overall, a distinct ecotoxicological hazard of PS-NPs at environmentally relevant concentrations was thoroughly characterized on two piscine cell lines. The effects were demonstrated to depend on size, exposure time and model, emphasizing the need for a comparative evaluation of endpoints between freshwater and marine ecosystems.

Transcriptome profiling of microdissected cortex and medulla unravels functional regionalization in the European sea bass Dicentrarchus labrax thymus

The thymus is a sophisticated primary lymphoid organ in jawed vertebrates, but knowledge on teleost thymus remains scarce. In this study, for the first time in the European sea bass, laser capture microdissection was leveraged to collect two thymic regions based on histological features, namely the cortex and the medulla. The two regions were then processed by RNAseq and in-depth functional transcriptome analyses with the aim of revealing differential gene expression patterns and gene sets enrichments, ultimately unraveling unique microenvironments imperative for the development of functional T cells. The sea bass cortex emerged as a hub of T cell commitment, somatic recombination, chromatin remodeling, cell cycle regulation, and presentation of self antigens from autophagy-, proteasome- or proteases-processed proteins. The cortex therefore accommodated extensive thymocyte proliferation and differentiation up to the checkpoint of positive selection. The medulla instead appeared as the center stage in autoimmune regulation by negative selection and deletion of autoreactive T cells, central tolerance mechanisms and extracellular matrix organization. Region-specific canonical markers of T and non-T lineage cells as well as signals for migration to/from, and trafficking within, the thymus were identified, shedding light on the highly coordinated and exquisitely complex bi-directional interactions among thymocytes and stromal components. Markers ascribable to thymic nurse cells and poorly characterized post-aire mTEC populations were found in the cortex and medulla, respectively. An in-depth data mining also exposed previously un-annotated genomic resources with differential signatures. Overall, our findings contribute to a broader understanding of the relationship between regional organization and function in the European sea bass thymus, and provide essential insights into the molecular mechanisms underlying T-cell mediated adaptive immune responses in teleosts.

Antibacterial and anticancer activity of two NK-lysin-derived peptides from the Antarctic teleost Trematomus bernacchii

The NK-lysin antimicrobial peptide, first identified in mammals, possesses both antibacterial and cytotoxic activity against cancer cell lines. Homologue peptides isolated from different fish species have been examined for their functional characteristics in the last few years. In this study, a NK-lysin transcript was identified in silico from the head kidney transcriptome of the Antarctic teleost Trematomus bernacchii. The corresponding amino acid sequence, slightly longer than NK-lysins of other fish species, contains six cysteine residues that in mammalian counterparts form three disulphide bridges. Real time-PCR analysis indicated its predominant expression in T. bernacchii immune-related organs and tissues, with greatest mRNA abundance detected in gills and spleen. Instead of focusing on the full T. bernacchii derived NK-lysin mature molecule, we selected a 27 amino acid residue peptide (named NKL-WT), corresponding to the potent antibiotic NK-2 sequence found in human NK-lysin. Moreover, we designed a mutant peptide (named NKL-MUT) in which two alanine residues substitute the two cysteines found in the NKL-WT. The two peptides were obtained by solid phase organic synthesis to investigate their functional features. NKL-WT and NKL-MUT displayed antibacterial activity against the human pathogenic bacterium Enterococcus faecalis and the ESKAPE pathogen Acinetobacter baumannii, respectively. Moreover, at the determined Minimum Inhibitory Concentration and Minimum Bactericidal Concentration values against these pathogens, both peptides showed high selectivity as they did not exhibit any haemolytic activity on erythrocytes or cytotoxic activity against mammalian primary cell lines. Finally, the NKL-MUT selectively triggers the killing of the melanoma cell line B16F10 by means of a pro-apoptotic pathway at a concentration range in which no effects were found in normal mammalian cell lines. In conclusion, the two peptides could be considered as promising candidates in the fight against antibiotic resistance and tumour proliferative action, and also be used as innovative adjuvants, either to decrease chemotherapy side effects or to enhance anticancer drug activity.

First evidence of in vitro cytotoxic effects of marine microlitter on Merluccius merluccius and Mullus barbatus, two Mediterranean commercial fish species

Marine litter is composed mainly of plastics and is recognized as a serious threat to marine ecosystems. Ecotoxicological approaches have started elucidating the potential severity of microplastics (MPs) in controlled laboratory studies with pristine materials but no information exists on marine environmental microlitter as a whole. Here, we characterized the litter in the coastal Northern Tyrrhenian sea and in the stomach of two fish species of socio-economic importance, and exposed primary cell cultures of mucosal and lymphoid organs to marine microlitter for evaluating possible cytotoxic effects. An average of 0.30 ± 0.02 microlitter items m^-3 was found in water samples. μFT-IR analysis revealed that plastic particles, namely HDPE, polyamide and polypropylene were present in 100% and 83.3% of Merluccius merluccius and Mullus barbatus analyzed, which overall ingested 14.67 ± 4.10 and 5.50 ± 1.97 items/individual, respectively. Moreover, microlitter was confirmed as a vector of microorganisms. Lastly, the apical end-point of viability was found to be significantly reduced in splenic cells exposed in vitro to two microlitter conditions. Considering the role of the spleen in the mounting of adaptive immune responses, our results warrant more in-depth investigations for clarifying the actual susceptibility of these two species to anthropogenic microlitter.

Gut immunity in European sea bass (Dicentrarchus labrax): a review

In this review, we summarize and discuss the trends and supporting findings in scientific literature on the gut mucosa immune role in European sea bass (Dicentrarchus labrax L.). Overall, the purpose is to provide an updated overview of the gastrointestinal tract functional regionalization and defence barriers. A description of the available information regarding immune cells found in two immunologically-relevant intestinal compartments, namely epithelium and lamina propria, is provided. Attention has been also paid to mucosal immunoglobulins and to the latest research investigating gut microbiota and dietary manipulation impacts. Finally, we review oral vaccination strategies, as a safe method for sea bass vaccine delivery.

Vaccines and immune protection of principal Mediterranean marine fish species

This review describes and summarizes the knowledge on established and experimental vaccines developed against viral and bacterial pathologies affecting the most important farmed marine finfish species present in the Mediterranean area, namely European seabass Dicentrarchus labrax, sea bream Sparus aurata, turbot Psetta maxima and meagre Argyrosomus regius. The diseases that have been recorded in seabass, sea bream and meagre are caused by bacteria Vibrio anguillarum, Photobacterium damselae, Tenacibaculum maritimum as well as by viruses such as Viral Encephalopathy and Retinopathy/Viral Nervous Necrosis and Lymphocystic disease. The main pathologies of turbot are instead bacteriosis provoked by Tenacibaculum maritimum, Aeromonas sp. and Vibrio anguillarum, and virosis by viral hemorrhagic septicaemia virus. Some vaccines have been optimized and are now regularly available for the majority of the above-mentioned pathogens. A measurable immune protection has been conferred principally against Vibrio anguillarum, Photobacterium damselae sub. piscicida and VER/VNN.

The incidence of major stroke subtypes in southern Italy: a population-based study

BACKGROUND AND PURPOSE

Stroke is characterized by well-defined clinical major subtypes, but there are few studies on incidence rates, aetiologies and outcomes in population-based setting. We assessed the age/sex incidence of the major stroke subtypes in a region of Southern Italy.

METHODS

We established a multisource, prospective population-based register in Puglia, Southern Italy to identify all residents with a first-ever stroke between 1 January 2001 and 31 December 2002.

RESULTS

One hundred and twenty-seven first-ever strokes were diagnosed, and stroke subtype was defined in 119 cases. The incidence rates per 100 000 adjusted to the European population (AEP) were 112 for cerebral infarction (CI), 30 for intracerebral haemorrhage (IH), four for subarachnoid haemorrhage (SH) and nine for undetermined stroke (US). The incidence rates for CI, IH and US approximately doubled with each decade of life and were higher in men. AEP incidence rates for CI in the age groups 45-84 were lower compared to other studies, whilst the corresponding rates for IH were higher.

CONCLUSIONS

This population had a lower incidence of CI compared to other population-based studies from Northern Europe and the United States. Furthermore, with the projected increase in the segment of the very old in the general population, our data indicate that both CI and IH will dramatically increase in the near future.

Fusariosis and skin T cell lymphoma: concomitant more than a differential diagnosis

Cytotoxic T cell lymphomas of the skin include a spectrum of a peripheral T cell and natural killer (NK) cell lymphomas with primary and secondary skin manifestation and bad prognosis. Fusarium species have recently emerged as the second most common pathogenic fungi in immunocompromised patients, and they are moderately resistant to most antifungal agents. We report a woman with concomitant cytotoxin T cell lymphomas of the skin and Fusarium spp infection. Patient was treated at the same time with antiblastic and antifungal therapy. First line antifungal therapy was amphotericin B-lipid complex (3 mg/Kg iv/die) and then for clinical failure voriconazole (6 mg/Kg bid, loading dose and 4 mg /Kg bid). Lymphoma was treated with a CHOEP 21 regiment without remission and after with gemcitabine and vinerolbine. Patient presented a partial remission of cutaneous and pulmonary lesions. Our case is intrinsically interesting because Fusarium infection was concomitant to cutaneous lymphoma and did non occur during neutropenic phases of chemotherapy. In a case with multiple ulcerated nodules of the skin is very important to discriminate from disseminated cutaneous Fusarium infection and neoplastic conditions such as cutaneous lymphoma. Early treatment of Fusarium infection in a patient with neoplastic disease could avoid a dissemination during immunosuppressive condition caused by antiblastic therapy.

Low Incidence of Stroke in Southern Italy

Background and Purpose— Although a lower incidence of stroke has been observed in the Mediterranean area compared to other European countries, this is based on only a few studies. We sought to determine the incidence and 28-day case-fatality of stroke through a population-based stroke register in a rural area in Southern Italy, characterized by a stroke unit in the referral hospital.

Methods— We established a multisource prospective population-based register in a well defined geographic area of 38 735 inhabitants in Puglia, Southern Italy. We identified all subjects in the study area with a first-ever stroke between January 1, 2001 and December 31, 2002.

Results— We identified 127 first-ever strokes (77 males, 50 females) during the two-year study period. Hospitalization was 95%: 92 cases (72.4%) were cerebral infarction, 24 (18.9%) intracerebral hemorrhage, 3 (2.4%) subarachnoid hemorrhage, and 8 (6.3%) were unclassifiable strokes. The overall crude annual incidence was 1.6 per 1000 (95%CI: 1.4 to 1.9), 2.0 for males (95% CI:1.6 to 2.5), and 1.3 for females (95% CI:0.9 to 1.6). The incidence rates standardized to the 2001 European and world populations were respectively 1.5 (2.0 for males and 1.3 for females) and 0.8 (0.9 for males and 0.6 for females). Incidence rates progressively increased with age in both sexes, reaching their peak at 85 years or more (21.4/1000 overall, 35.0 for men and 13.4 for women). The 28-day case-fatality was 18.1%.

Conclusions— Our study supports previous findings of lower incidence of stroke in the Mediterranean area, whereas the case-fatality in our study was lower than in previous studies from Italy. Further studies are needed to determine the role of prompt referral and stroke units on prognosis in population-based setting.

Modified mini-abdominoplasty: navel transposition and horizontal residual scar

The classic mini-abdominoplasty is a surgery generally indicated for cases in which cutaneous laxity of the abdomen's inferior region is associated with adiposity. However, in some cases, the characteristics of the abdomen are such that resort to a traditional mini-abdominoplasty would involve an unsatisfactory final result due to the unavoidable caudalization of the navel. In answer to this problem, Pontes developed the type 4 modified mini-abdominoplasty. This procedure adds to the classic technique a complete resection of the navel and its transposition so that it leaves a residual vertical scar. With our version of the technique, the scar is more aesthetic in shape and appearance, horizontal, and parallel to the suprapubic scar.