Valutazione di marker diagnostici, epidemiologia e nuove prospettive terapeutiche nell' avvelenamento da rodenticidi anticoagulanti nel cane.

In Medicina Veterinaria l'avvelenamento da rodenticidi anticoagulanti è conosciuto e studiato ormai da anni, essendo una delle intossicazioni più comunemente riscontrate nelle specie non target. In letteratura si rinvengono numerose pubblicazioni ma alcuni aspetti sono rimasti ancora inesplorati.Questo studio si propone di valutare il processo infiammatorio, mediante le proteine di fase acuta (APPs), in corso di fenomeni emorragici, prendendo come modello reale un gruppo di soggetti accidentalmente avvelenati da rodenticidi anticoagulanti. I 102 soggetti avvelenati presentano un valore più elevato di proteina C reattiva (CRP)con una mediana di 4.77 mg/dl statisticamente significativo rispetto alla mediana delle due popolazioni di controllo di pari entità numerica create con cross match di sesso, razza ed età; rispettivamente 0.02 mg/dl dei soggetti sani e 0.37 mg/dl dei soggetti malati di altre patologie. Inoltre all'interno del gruppo dei soggetti avvelenati un valore di CRP elevato all'ammissione può predisporre al decesso. La proteina C reattiva assume quindi un ruolo diagnostico e prognostico in questo avvelenamento. Un'altra finalità, di non inferiore importanza, è quella di definire una linea guida terapeutica con l'ausilio di biomarker coagulativi e di valutare la sicurezza della vitamina K per via endovenosa: in 73 cani, non in terapia con vitamina k, intossicati da rodenticidi anticoagulanti, i tempi della coagulazione (PT ed aPTT) ritornano nel range di normalità dopo 4 ore dalla prima somministrazione di 5 mg/kg di vitamina k per via endovenosa e nessun soggetto durante e dopo il trattamento ha manifestato reazioni anafilattiche, nessuno dei pazienti ha necessitato trasfusione ematica e tutti sono sopravvissuti. Infine si è valutata l'epidemiologia dell'ingestione dei prodotti rodenticidi nella specie oggetto di studio e la determinazione dei principi attivi mediante cromatografia liquida abbinata a spettrofotometria di massa (UPLC-MS/MS).

Natural compounds Camptothecin and Triptolide: highly specific enzyme inhibitors and tools to dissect transcriptional functions

With this work I elucidated new and unexpected mechanisms of two strong and highly specific transcription inhibitors: Triptolide and Campthotecin. Triptolide (TPL) is a diterpene epoxide derived from the Chinese plant Trypterigium Wilfoordii Hook F. TPL inhibits the ATPase activity of XPB, a subunit of the general transcription factor TFIIH. In this thesis I found that degradation of Rbp1 (the largest subunit of RNA Polymerase II) caused by TPL treatments, is preceded by an hyperphosphorylation event at serine 5 of the carboxy-terminal domain (CTD) of Rbp1. This event is concomitant with a block of RNA Polymerase II at promoters of active genes. The enzyme responsible for Ser5 hyperphosphorylation event is CDK7. Notably, CDK7 downregulation rescued both Ser5 hyperphosphorylation and Rbp1 degradation triggered by TPL. Camptothecin (CPT), derived from the plant Camptotheca acuminata, specifically inhibits topoisomerase 1 (Top1). We first found that CPT induced antisense transcription at divergent CpG islands promoter. Interestingly, by immunofluorescence experiments, CPT was found to induce a burst of R loop structures (DNA/RNA hybrids) at nucleoli and mitochondria. We then decided to investigate the role of Top1 in R loop homeostasis through a short interfering RNA approach (RNAi). Using DNA/RNA immunoprecipitation techniques coupled to NGS I found that Top1 depletion induces an increase of R loops at a genome-wide level. We found that such increase occurs on the entire gene body. At a subset of loci R loops resulted particularly stressed after Top1 depletion: some of these genes showed the formation of new R loops structures, whereas other loci showed a reduction of R loops. Interestingly we found that new peaks usually appear at tandem or divergent genes in the entire gene body, while losses of R loop peaks seems to be a feature specific of 3’ end regions of convergent genes.

CO2 utilization and alternative solvents: effective tools for sustainable applications

The growing concentration of CO2 in the atmosphere and its harmful consequences has led the scientific community to direct its efforts towards sustainable processes. Among the possible approaches, the use of CO2 and alternative solvents are two strategies that are having widespread diffusion. In this work the reuse of CO2 is expressed by using it as a reaction reagent and as trigger to change the physical properties of a catalyst thus facilitating its recovery. As regards the CO2 use as reagent, two catalytic systems have been developed for the conversion of CO2 and epoxides into cyclic carbonates, used in the synthesis of polymers and as aprotic solvents. Homogeneous catalysts made by choline-based eutectic mixtures and heterogeneous catalysts made from biopolymers and waste pyrolysis have been synthesized and tested on this reaction. The carbonate interchange reaction (CIR) of a diol with a linear carbonate (as dimethyl carbonate) is an interesting alternative, for the synthesis of cyclic carbonates; as the second application of CO2 as polarity trigger, it was used for catalyst recovery. In fact DBU, here used as catalyst, is part of the so called “switchable solvents”: they can pass from a less-polar to a more-polar form (and from being soluble to non-soluble in the reaction mixture) when reacting with CO2 in presence of water or alcohols. Also in this case, heterogeneous catalysts made from biopolymers and waste pyrolysis have been synthesized and tested on CIR. As for the use of alternative solvents, this work focuses on the use of Deep Eutectic Solvents (DESs). They are a new generation of solvents composed by a mixture of two or more substances, liquid at room temperature, and non-volatile. New and biobased DESs were here used: i) as reaction media to carry out chemoenzymatic epoxidation; ii) in the extraction of astaxanthin from microalgae culture.