Anticancer drug screening from images of zebrafish embryogenesis

During the previous 10 years, global R&D expenditure in the pharmaceuticals and biotechnology sector has steadily increased, without a corresponding increase in output of new medicines. To address this situation, the biopharmaceutical industry's greatest need is to predict the failures at the earliest possible stage of the drug development process. A major key to reducing failures in drug screenings is the development and use of preclinical models that are more predictive of efficacy and safety in clinical trials. Further, relevant animal models are needed to allow a wider testing of novel hypotheses. Key to this is the developing, refining, and validating of complex animal models that directly link therapeutic targets to the phenotype of disease, allowing earlier prediction of human response to medicines and identification of safety biomarkers. Morehover, well-designed animal studies are essential to bridge the gap between test in cell cultures and people. Zebrafish is emerging, complementary to other models, as a powerful system for cancer studies and drugs discovery. We aim to investigate this research area designing a new preclinical cancer model based on the in vivo imaging of zebrafish embryogenesis. Technological advances in imaging have made it feasible to acquire nondestructive in vivo images of fluorescently labeled structures, such as cell nuclei and membranes, throughout early Zebrafishsh embryogenesis. This In vivo image-based investigation provides measurements for a large number of features at cellular level and events including nuclei movements, cells counting, and mitosis detection, thereby enabling the estimation of more significant parameters such as proliferation rate, highly relevant for investigating anticancer drug effects. In this work, we designed a standardized procedure for accessing drug activity at the cellular level in live zebrafish embryos. The procedure includes methodologies and tools that combine imaging and fully automated measurements of embryonic cell proliferation rate. We achieved proliferation rate estimation through the automatic classification and density measurement of epithelial enveloping layer and deep layer cells. Automatic embryonic cells classification provides the bases to measure the variability of relevant parameters, such as cell density, in different classes of cells and is finalized to the estimation of efficacy and selectivity of anticancer drugs. Through these methodologies we were able to evaluate and to measure in vivo the therapeutic potential and overall toxicity of Dbait and Irinotecan anticancer molecules. Results achieved on these anticancer molecules are presented and discussed; furthermore, extensive accuracy measurements are provided to investigate the robustness of the proposed procedure. Altogether, these observations indicate that zebrafish embryo can be a useful and cost-effective alternative to some mammalian models for the preclinical test of anticancer drugs and it might also provides, in the near future, opportunities to accelerate the process of drug discovery.

Diritti umani e diritto alla salute - la questione dell’accesso ai farmaci come un problema di Giustizia Globale

Riconosciuto il problema dell’accesso ai farmaci come un problema di giustizia globale, la dissertazione, da un lato, è incentrata sullo studio dei diritti umani e sul diritto alla salute da una prospettiva giusfilosofica e, dall’altro, è finalizzata ad analizzare la disciplina brevettuale internazionale, sia approfondendo gli interessi realmente in gioco, sia studiando la struttura economica del brevetto stesso. Si è cercato quindi di guardare a tali interessi da una nuova prospettiva, ipotizzando una gerarchia di valori che sia completa e coerente con gli obiettivi che la dottrina, la giurisprudenza, nonché il diritto internazionale formalmente enunciano. Il progetto di ricerca vuole, in definitiva, arrivare a proporre nuove soluzioni giuridiche al problema dell’accesso ai farmaci. La dissertazione svolge pertanto uno studio critico della proposta di Thomas Pogge, di natura politica e giuridica e sorretta da istanze filosofiche, volta alla soluzione del problema dell’accesso ai farmaci, i.e. l’Health Impact Fund (HIF). Proposta che pone radicalmente in discussione, anche concretamente, il dogma del monopolio concesso con la privativa quale ricompensa per i costi di R&D sostenuti dai titolari dei brevetti e che pone, invece, l’accento sull’effettivo impatto sulla salute globale di ogni singola invenzione. Analizzandone approfonditamente gli aspetti più rilevanti, si passano poi in rassegna, criticamente, le proposte, alternative o di riforma, del sistema di proprietà intellettuale, volte al miglioramento dell’accesso ai farmaci; a tal proposito, si propone quindi una riforma transitoria della disciplina brevettuale, c.d. Trading Time for Space (TTS), che prevede un allungamento temporale dell’esclusiva brevettuale (Time) in cambio della vendita da parte del titolare della privativa del farmaco ad un prezzo accessibile nei Paesi in via di sviluppo (Space).

GNSS interference management techniques against malicious attacks

This thesis collects the outcomes of a Ph.D. course in Telecommunications Engineering and it is focused on the study and design of possible techniques able to counteract interference signal in Global Navigation Satellite System (GNSS) systems. The subject is the jamming threat in navigation systems, that has become a very increasingly important topic in recent years, due to the wide diffusion of GNSS-based civil applications. Detection and mitigation techniques are developed in order to fight out jamming signals, tested in different scenarios and including sophisticated signals. The thesis is organized in two main parts, which deal with management of GNSS intentional counterfeit signals. The first part deals with the interference management, focusing on the intentional interfering signal. In particular, a technique for the detection and localization of the interfering signal level in the GNSS bands in frequency domain has been proposed. In addition, an effective mitigation technique which exploits the periodic characteristics of the common jamming signals reducing interfering effects at the receiver side has been introduced. Moreover, this technique has been also tested in a different and more complicated scenario resulting still effective in mitigation and cancellation of the interfering signal, without high complexity. The second part still deals with the problem of interference management, but regarding with more sophisticated signal. The attention is focused on the detection of spoofing signal, which is the most complex among the jamming signal types. Due to this highly difficulty in detect and mitigate this kind of signal, spoofing threat is considered the most dangerous. In this work, a possible techniques able to detect this sophisticated signal has been proposed, observing and exploiting jointly the outputs of several operational block measurements of the GNSS receiver operating chain.