Acute administration of the olive constituent, oleuropein, combined with ischemic postconditioning increases myocardial protection by modulating oxidative defense

Oleuropein, one of the main polyphenolic constituents of olive, is cardioprotective against ischemia reperfusion injury (IRI). We aimed to assess the cardioprotection afforded by acute administration of oleuropein and to evaluate the underlying mechanism. Importantly, since antioxidant therapies have yielded inconclusive results in attenuating IRI-induced damage on top of conditioning strategies, we investigated whether oleuropein could enhance or imbed the cardioprotective manifestation of ischemic postconditioning (PostC). Oleuropein, given during ischemia as a single intravenous bolus dose reduced the infarct size compared to the control group both in rabbits and mice subjected to myocardial IRI. None of the inhibitors of the cardioprotective pathways, l-NAME, wortmannin and AG490, influence its infarct size limiting effects. Combined oleuropein and PostC cause further limitation of infarct size in comparison with PostC alone in both animal models. Oleuropein did not inhibit the calcium induced mitochondrial permeability transition pore opening in isolated mitochondria and did not increase cGMP production. To provide further insights to the different cardioprotective mechanism of oleuropein, we sought to characterize its anti-inflammatory potential in vivo. Oleuropein, PostC and their combination reduce inflammatory monocytes infiltration into the heart and the circulating monocyte cell population. Oleuropein's mechanism of action involves a direct protective effect on cardiomyocytes since it significantly increased their viability following simulated IRI as compared to non-treated cells. Οleuropein confers additive cardioprotection on top of PostC, via increasing the expression of the transcription factor Nrf-2 and its downstream targets in vivo. In conclusion, acute oleuropein administration during ischemia in combination with PostC provides robust and synergistic cardioprotection in experimental models of IRI by inducing antioxidant defense genes through Nrf-2 axis and independently of the classic cardioprotective signaling pathways (RISK, cGMP/PKG, SAFE)

De novo assembly of the olive fruit fly (Bactrocera oleae) genome with linked-reads and long-read technologies minimizes gaps and provides exceptional Y chromosome assembly

Background: The olive fruit fly, Bactrocera oleae, is the most important pest in the olive fruit agribusiness industry. This is because female flies lay their eggs in the unripe fruits and upon hatching the larvae feed on the fruits thus destroying them. The lack of a high-quality genome and other genomic and transcriptomic data has hindered progress in understanding the fly’s biology and proposing alternative control methods to pesticide use. Results: Genomic DNA was sequenced from male and female Demokritos strain flies, maintained in the laboratory for over 45 years. We used short-, mate-pair-, and long-read sequencing technologies to generate a combined male-female genome assembly (GenBank accession GCA_001188975.2). Genomic DNA sequencing from male insects using 10x Genomics linked-reads technology followed by mate-pair and long-read scaffolding and gap-closing generated a highly contiguous 489 Mb genome with a scaffold N50 of 4.69 Mb and L50 of 30 scaffolds (GenBank accession GCA_001188975.4). RNA-seq data generated from 12 tissues and/or developmental stages allowed for genome annotation. Short reads from both males and females and the chromosome quotient method enabled identification of Y-chromosome scaffolds which were extensively validated by PCR. Conclusions: The high-quality genome generated represents a critical tool in olive fruit fly research. We provide an extensive RNA-seq data set, and genome annotation, critical towards gaining an insight into the biology of the olive fruit fly. In addition, elucidation of Y-chromosome sequences will advance our understanding of the Y-chromosome’s organization, function and evolution and is poised to provide avenues for sterile insect technique approaches

Contraindications to immunotherapy: a global approach

Background Recommendations on contraindications to allergen immunotherapy (AIT) have been independently developed by National and International Societies/Academies. AIT contraindications are mainly based on case reports, case-series, or experts' opinion, while evidence-based information is limited. The aim of the present review was to describe existing guidelines on contraindications to AIT and to highlight differences between them. Main body An extended review of the literature regarding contraindications to AIT for respiratory allergy and venom hypersensitivity was performed. Furthermore, Societies and Academies registered in the World Allergy Organization and EAACI databases, were asked for additional information. Only AIT guidelines published under official auspicies were included. A large heterogeneity among the various recommendations on contraindications was registered. Common contraindications to most of the guidelines were: lack of adherence, pregnancy before the start of AIT, the use of beta-blockers, certain age groups, uncontrolled asthma, autoimmune diseases and malignancies. Conclusion As new data arise, revisions might soon be needed allowing AIT in the cases of patients treated with ACE inhibitors and beta-blockers, in elderly patients and in patients with concomitant autoimmune diseases and neoplasias in remission. The decision to prescribe AIT is always tailor-made, balancing risk vs benefit. Creating globally accepted guidelines would help Allergologists in their decision making

Food-Induced Anaphylaxis Year in Review

Food allergy is increasing; as a consequence, food-induced anaphylaxis is also becoming a growing problem. Our understanding of the mechanisms of tolerance is still basic and requires much more research before it becomes helpful in guiding our interventions. However, empirical approaches with oral immunotherapy and food introduction manipulation appear promising, although standardization is required before employing them on a large scale. Furthermore, education and public health measures can be helpful for the increasing proportion of the population at risk. © 2015, Springer International Publishing AG

On the environmental impact of freshwater fish farms in Greece and in Iceland

In the present study, we focused on the nitrogen and phosphorus levels generated by open flow freshwater fish farms in Greece and Iceland where salmonid fish are cultivated. There are several differences in the legislation and regulation of the aquaculture sector in Greece and in Iceland. Nevertheless, in both countries, environmental protection agencies need accurate information for nutrient processes in order to evaluate the environmental influence on surrounding waters by salmon aquaculture. Data were collected from surveys of 21 freshwater fish farms in Greece and 9 in Iceland. The surveyed farms practiced intensive production methods. The concentrations of nitrogen and phosphorus in farms’ discharges were used to estimate organic load generated. The collected data were compared with data from the literature for the production Salmonids for species cultivated in Iceland (Arctic charr, Atlantic salmon) and in Greece (Rainbow trout). The results of the analysis indicate that in both countries the highest concentrations of nitrogen and phosphorus discharges of fish farms exhibits a variability which can be attributed to the total biomass of produced fish, fish feed and feeding management protocols used, species cultivated and ambient temperature. During the last 30 years, there was a significant reduction in the amount of nutrients generated by fish farms, which to a great extent is a result of lower levels of protein content in fish feeds and improved feed conversion efficiency. It is estimated that over the past 30 years, the combined effect of reduced nitrogen and phosphorus content and the improvements in Feed Conversion Efficiency, resulted in about 50% reduction in the nutrients generated by every Kg of farmed fish produced. Nevertheless, this significant improvement was easily offset by and increased production of fresh water fish farms exhibited in both countries. It seems possible that legislative measures combined with improvements in technology and feed management of fish farms will continue to be good option of minimizing the environmental impact of fish farms in the future. © 2017 Mavraganis et al

Decoding the reproductive system of the olive fruit fly, Bactrocera oleae

In most diploid organisms, mating is a prerequisite for reproduction and, thus, critical to the maintenance of their population and the perpetuation of the species. Besides the importance of understanding the fundamentals of reproduction, targeting the reproductive success of a pest insect is also a promising method for its control, as a possible manipulation of the reproductive system could affect its destructive activity. Here, we used an integrated approach for the elucidation of the reproductive system and mating procedures of the olive fruit fly, Bactrocera oleae. Initially, we performed a RNAseq analysis in reproductive tissues of virgin and mated insects. A comparison of the transcriptomes resulted in the identification of genes that are differentially expressed after mating. Functional annotation of the genes showed an alteration in the metabolic, catalytic, and cellular processes after mating. Moreover, a functional analysis through RNAi silencing of two differentially expressed genes, yellow-g and troponin C, resulted in a significantly reduced oviposition rate. This study provided a foundation for future investigations into the olive fruit fly’s reproductive biology to the development of new exploitable tools for its control. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Anosmic flies: what Orco silencing does to olive fruit flies

Background: The olive fruit fly (Bactrocera oleae) is the most destructive pest of the olive cultivation worldwide causing significant production losses and olive fruit impoverishment, as its larvae feed exclusively on the olive fruit. Reproductive and sexual behavior, as well as host-plant recognition of the fly, are highly dependent on its chemosensory system. Therefore, exploring the role of genes that play a critical role in olfaction, could reveal potential molecular targets that determine species-specific features on chemical communication and could be used to impair sexual behavior. Results: In this study we identified the gene that encodes the conserved olfactory co-receptor Orco (Odorant receptor co-receptor), which interacts with all divergent insect odorant receptors, and investigated how disruption of its expression affects chemoreception. We initially searched the expression profile of Bo-Orco in both sexes during sexual maturation, as well as pre- and post-mating communication by relative quantitative real time PCR (qRT-PCR) analysis suggesting that Bo-Orco was abundantly expressed in sexually mature adults. We further investigated the functional role of Bo-Orco in mating and oviposition behavior via transient gene silencing that was performed through in vivo dsRNA hemolymph injections in sexually mature flies 7 days after eclosion. Orco-knockdown phenotypes in both sexes showed reduced copulation rates in mating competitiveness tests, possibly through impaired olfactory-mediated detection of sex pheromone. In addition, oviposition was significantly inhibited in dsRNA-Orco injected females in a post-mating behavior test. Conclusions: Our results demonstrate that Orco plays a crucial role in the reproductive behavior of the olive fruit fly, since pre- and post-mating processes were affected. This is the first report in the olive fruit fly that links the chemosensory pathway with the mating behavior and the reproductive potential at a molecular basis, rendering this gene a potential target for the improvement of the olive fruit fly population control techniques. © 2020, The Author(s)