Side Chain Hydrophobicity Modulates Therapeutic Activity and Membrane Selectivity of Antimicrobial Peptide Mastoparan-X

The discovery of new anti-infective compounds is stagnating and multi-resistant bacteria continue to emerge, threatening to end the "antibiotic era". Antimicrobial peptides (AMPs) and lipo-peptides such as daptomycin offer themselves as a new potential class of antibiotics; however, further optimization is needed if AMPs are to find broad use as antibiotics. In the present work, eight analogues of mastoparan-X (MPX) were investigated, having side chain modifications in position 1, 8 and 14 to modulate peptide hydrophobicity. The self-association properties of the peptides were characterized, and the peptide-membrane interactions in model membranes were compared with the bactericidal and haemolytic properties. Alanine substitution at position 1 and 14 resulted in higher target selectivity (red blood cells versus bacteria), but also decreased bactericidal potency. For these analogues, the gain in target selectivity correlated to biophysical parameters showing an increased effective charge and reduction in the partitioning coefficient for membrane insertion. Introduction of an unnatural amino acid, with an octyl side chain by amino acid substitution, at positions 1, 8 and 14 resulted in increased bactericidal potency at the expense of radically reduced membrane target selectivity. Overall, optimized membrane selectivity or bactericidal potency was achieved by changes in side chain hydrophobicity of MPX. However, enhanced potency was achieved at the expense of selectivity and vice versa in all cases

Reference gene validation for quantitative RT-PCR during biotic and abiotic stresses in Vitis vinifera

Grapevine is one of the most cultivated fruit crop worldwide with Vitis vinifera being the species with the highest economical importance. Being highly susceptible to fungal pathogens and increasingly affected by environmental factors, it has become an important agricultural research area, where gene expression analysis plays a fundamental role. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is currently amongst the most powerful techniques to perform gene expression studies. Nevertheless, accurate gene expression quantification strongly relies on appropriate reference gene selection for sample normalization. Concerning V. vinifera, limited information still exists as for which genes are the most suitable to be used as reference under particular experimental conditions. In this work, seven candidate genes were investigated for their stability in grapevine samples referring to four distinct stresses (Erysiphe necator, wounding and UV-C irradiation in leaves and Phaeomoniella chlamydospora colonization in wood). The expression stability was evaluated using geNorm, NormFinder and BestKeeper. In all cases, full agreement was not observed for the three methods. To provide comprehensive rankings integrating the three different programs, for each treatment, a consensus ranking was created using a non-weighted unsupervised rank aggregation method. According to the last, the three most suitable reference genes to be used in grapevine leaves, regardless of the stress, are UBC, VAG and PEP. For the P. chlamydospora treatment, EF1, CYP and UBC were the best scoring genes. Acquaintance of the most suitable reference genes to be used in grapevine samples can contribute for accurate gene expression quantification in forthcoming studiesinfo:eu-repo/semantics/publishedVersio

RNA-seq analysis in plant–fungus interactions

Many fungi are pathogens that infect important food and plantation crops, reducing both yield and quality of food products. Understanding plant–fungus interactions is crucial as knowledge in this area is required to formulate sustainable strategies to improve plant health and crop productivity. High-throughput RNA-sequencing (RNA-seq) enables researchers to gain insights of the mixed and multispecies transcriptomes in plant–fungus interactions. Interpretation of huge data generated by RNA-seq has led to new insights in this area, facilitating a system approach in unraveling interactions between plant hosts and fungal pathogens. In this review, the application and challenges of RNA-seq analysis in plant–fungus interactions will be discussed

The medical error in human reproduction : wrongful birth-wrongful life, medical liability for wrongful life

Η σύγχρονη Ιατρική Επιστήμη μέσω του προγεννητικού ελέγχου παρέχει πλέον όλα τα εχέγγυα στους μέλλοντες γονείς για την ελαχιστοποίηση του κινδύνου γέννησης ενός παιδιού με σοβαρά προβλήματα υγείας. Ωστόσο, το ανθρώπινο λάθος πάντα μπορεί να παρεισφρήσει σε μία ιατρική πράξη. Έτσι, ενώ τα περισσότερα ζητήματα αστικής ιατρικής ευθύνης ρυθμίζονται στον ΑΚ , η περίπτωση αστικής ιατρικής ευθύνης , κατά την οποία γεννάται ένα παιδί με εγγενές πρόβλημα υγείας , το οποίο ο γιατρός δεν διέγνωσε ως όφειλε και μπορούσε κατά τον προγεννητικό έλεγχο, γεννά μείζονα και δυσεπίλυτα νομικά, κοινωνικά και ηθικά διλήμματα. Στην περίπτωση αυτή, το κρίσιμο είναι, ότι το πρόβλημα υγείας του παιδιού δεν συνδέεται αιτιωδώς με το ιατρικό σφάλμα αλλά το τελευταίο προϋπήρχε και είναι σύμφυτο με την ύπαρξη του παιδιού. Τα διλήμματα , που εγείρονται έγκεινται στο αν μπορεί και ποιος μπορεί να είναι ο δικαιούχος της αποζημίωσης ; Κατά πόσον μπορούν οι γονείς του άρρωστου τέκνου (περίπτωση wrongful birth) καθώς και το ίδιο το τέκνο (περίπτωση wrongful life) να εγείρουν αγωγή αποζημίωσης ; Εξομοιώνεται στις περιπτώσεις αυτές η γέννηση με ζημία ; Οι ανωτέρω υποθέσεις αναγνώρισης τέτοιων αξιώσεων αποζημίωσης στους γονείς και στα άρρωστα τέκνα, οι οποίες σημειωτέον διακρίνονται ως προς την αντιμετώπισή τους από την εγχώρια και τη διεθνή νομολογία , έχουν προκαλέσει μεγάλη διχογνωμία σε εθνικό και διεθνές επίπεδο. Τα ως άνω σύνθετα νομικά, κοινωνικά και ηθικά ζητήματα, που εγείρουν οι περιπτώσεις wrongful birth και wrongful life, είναι το αντικείμενο της παρούσας εργασίας μου, η οποία μέσα από την ενδελεχή επισκόπηση της θεωρίας και της νομολογίας , έχει σκοπό να αναδείξει το πρόβλημα , που υπάρχει σε όλες τις διαστάσεις του και να παρουσιάσει κριτικά τα διάφορα επιχειρήματα υπερ και κατά της αναγνώρισης τέτοιων αξιώσεων.The contemporary medical science through the prenatal medical check up , provides all the guarantees to future parents to minimize the risk of the birth of a child with serious health problems . However, human mistake can always get into a medical act . So, while most of urban medical malpractice are regulated in the Greek Civil Code, the case that a child is born with a native health problem , which the doctor didn’ t diagnose as due and could during the prenatal check, generates major and insoluble legal, social and moral dilemmas . In this case, the critical issue is that the child’ s health problem is not causally related to the medical mistake but the health problem was pre- existing and inherent in the existence of the child. The dilemmas, that arise lie to if someone can be or who can be the beneficiary of the compensation, whether the parents of the sick child (wrongful birth) and the child itself (wrongful life) can bring a lawsuit for compensation. Is the birth in these cases equated with damage ? The cases above of recognition of such claims for compensation to parents and sick children , which are distinguished from the fact that how they are dealt with by domestic and international case law, have sporked controversy at national and international level. These complex legal, social and moral issues raised by the cases of wrongful birth and wrongful life are the subject of my current master essay , which through the insider’s review of theory and law case , has a purpose to highlight the problem that exists in all its dimensions and to present critically the various arguments for and against the recognition of such claims