Inibitori della gelatinasi A nel trattamento del glioblastoma multiforme

Il mio lavoro di tesi, condotto presso il laboratorio di Biochimica della Facoltà di Farmacia dell’Università di Pisa, ha avuto come scopo la valutazione dell’attività di due inibitori selettivi di MMP-2, appartenenti alla classe degli N-O-isopropil sulfonamide idrossammati, in relazione all’invasività e alla vitalità cellulare, in cellule di glioma IV umano U87MG. I composti sono stati utilizzati a concentrazione nanomolare (selettività per la MMP-2) per il trattamento delle cellule. L’invasività è stata valutata utilizzando il saggio di invasività su matrigel (membrana basale ricostuita), mentre la vitalità con il saggio di vitalità cellulare MTS assay e la conta cellulare con il colorante Trypan Blue . I risultati hanno dimostrato che questi composti sono potenti inibitori dell’invasività (p<0.0001), e non hanno effetto sulla vitalità cellulare. In un secondo momento è stata valutata l’azione combinata della temozolomide con l’inibitore selettivo di MMP-2 CC27, sia su invasività che vitalità cellulare. I risultati dei trattamenti combinati hanno evidenziato un blocco sia di invasività che di vitalità cellulare

Biochemical characterization of a multi-drug resistant HIV-1 subtype AG reverse transcriptase: antagonism of AZT discrimination and excision pathways and sensitivity to RNase H inhibitors

We analyzed a multi-drug resistant (MR) HIV-1 re- verse transcriptase (RT), subcloned from a patient- derived subtype CRF02 AG, harboring 45 amino acid exchanges, amongst them four thymidine analog mutations (TAMs) relevant for high-level AZT (azi- dothymidine) resistance by AZTMP excision (M41L, D67N, T215Y, K219E) as well as four substitutions of the AZTTP discrimination pathway (A62V, V75I, F116Y and Q151M). In addition, K65R, known to an- tagonize AZTMP excision in HIV-1 subtype B was present. Although MR-RT harbored the most signif- icant amino acid exchanges T215Y and Q151M of each pathway, it exclusively used AZTTP discrimi- nation, indicating that the two mechanisms are mu- tually exclusive and that the Q151M pathway is ob- viously preferred since it confers resistance to most nucleoside inhibitors. A derivative was created, ad- ditionally harboring the TAM K70R and the rever- sions M151Q as well as R65K since K65R antago- nizes excision. MR-R65K-K70R-M151Q was compe- tent of AZTMP excision, whereas other combinations thereof with only one or two exchanges still pro- moted discrimination. To tackle the multi-drug resis- tance problem, we tested if the MR-RTs could still be inhibited by RNase H inhibitors. All MR-RTs exhibited similar sensitivity toward RNase H inhibitors be- longing to different inhibitor classes, indicating the importance of developing RNase H inhibitors further as anti-HIV drugs

Diagnostic Value of Choline PET in the Preoperative Localization of Hyperfunctioning Parathyroid Gland(s): A Comprehensive Overview

Hyperparathyroidism is a metabolic disorder characterized by the excessive production of the parathyroid hormone. The diagnosis is based on clinical and laboratory data. In most cases the only treatment is surgery and a correct preoperatory localization of the hyperfunctioning parathyroid gland(s) is essential. Currently, ultrasonography combined with [Tc-99m]Tc-MIBI parathyroid scintigraphy, optionally associated with single photon emission computed tomography/computed tomography (SPECT/CT), represent the standard preoperative imaging. In recent years, a number of studies have evaluated the potential role of choline positron emission tomography (PET) in hyperparathyroidism with promising results. Most of the recent evidence underlined its higher sensitivity and diagnostic accuracy in the localization of hyperfunctioning parathyroid glands. Choline PET has a higher spatial resolution that is useful for the detection of smaller parathyroid glands and it also has shorter examination times and favorable radiation exposure. These are just a few of the aspects that support it to overcome traditional imaging. Moreover, from the preliminary data, the choline uptake mechanism seems to also have an impact on its better performance. For these reasons, if first used as second level imaging in patients with negative or inconclusive traditional imaging results, several authors have supported its use as a first line investigation. This comprehensive overview aims to provide an accurate description of the preliminary results available in the literature about the use of choline PET/CT in hyperparathyroidism and to compare these results with the performance of traditional imaging methods

18F-Fluorocholine PET/CT, Tc-99m-MIBI and TC-99m-MDP SPECT/CT in Tertiary Hyperparathyroidism with Renal Osteodystrophy

Tertiary hyperparathyroidism (HPT) is a metabolic disorder characterized by the semi-autonomous hypersecretion of parathyroid hormone (PTH), leading to hypercalcemia. It can be the end result of persistent secondary hyperparathyroidism and is most commonly observed in patients with long-standing chronic kidney disease (CKD) and often after renal transplantation. Untreated HPT can lead to progressive bone disease, fibrocystic osteitis, and soft-tissue calcifications, along with other severe complications. In the 2009 Kidney Disease Improving Global Outcomes (KDIGO) guidelines, CKD-Mineral and Bone Disorder (CKD-MBD) is used to describe the broader clinical syndrome encompassing mineral, bone, and calcific cardiovascular abnormalities that develop as a complication of CKD. We report a 62-year-old female with a severe HPT evolved from advanced chronic kidney disease (stage 5D, KDIGO). Patient was evaluated with multimodality nuclear medicine functional imaging to assess hyperfunctioning parathyroid glands and bone lesions. Tc-99m-methoxyisobutylisonitrile (MIBI) dual-phase scintigraphy, Tc-99m-methylenediphosphonate (MDP) bone scan and 18F-Fluorocholine positron emission tomography/computed tomography ( 18F-FCH PET/CT) were performed before surgery

Comparison of the Diagnostic Value of MRI and Whole Body 18F-FDG PET/CT in Diagnosis of Spondylodiscitis

Spondylodiscitis is a spine infection for which a diagnosis by a magnetic resonance imaging (MRI) is considered the most appropriate imaging technique. The aim of this study was to compare the role of an F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) and an MRI in this field. For 56 patients with suspected spondylodiscitis for whom MRI and F-18-FDG PET/CT were performed, we retrospectively analyzed the results. Cohen's kappa was applied to evaluate the agreement between the two techniques in all patients and in subgroups with a different number of spinal districts analyzed by the MRI. Sensitivity, specificity, and accuracy were also evaluated. The agreements of the F-18-FDG PET/CT and MRI in the evaluation of the entire population, whole-spine MRI, and two-districts MRI were moderate (kappa = 0.456, kappa = 0.432, and kappa = 0.429, respectively). In patients for whom one-district MRI was performed, F-18-FDG PET/CT and MRI were both positive and completely concordant (kappa = 1). We also separately evaluated patients with suspected spondylodiscitis caused by Mycobacterium tuberculosis for whom the MRI and F-18-FDG PET/CT were always concordant excepting in 2 of the 18 (11%) patients. Sensitivity, specificity, and accuracy of the MRI and F-18-FDG PET/CT were 100%, 60%, 97%, and 92%, 100%, and 94%, respectively. Our results confirmed the F-18-FDG PET/CT diagnostic value in the diagnosis of spondylodiscitis is comparable to that of MRI for the entire spine evaluation. This could be considered a complementary technique or a valid alternative to MRI

Interplay between Human Cytomegalovirus and Intrinsic/Innate Host Responses: A Complex Bidirectional Relationship

The interaction between human cytomegalovirus (HCMV) and its host is a complex process that begins with viral attachment and entry into host cells, culminating in the development of a specific adaptive response that clears the acute infection but fails to eradicate HCMV. We review the viral and cellular partners that mediate early host responses to HCMV with regard to the interaction between structural components of virions (viral glycoproteins) and cellular receptors (attachment/entry receptors, toll-like receptors, and other nucleic acid sensors) or intrinsic factors (PML, hDaxx, Sp100, viperin, interferon inducible protein 16), the reactions of innate immune cells (antigen presenting cells and natural killer cells), the numerous mechanisms of viral immunoevasion, and the potential exploitation of events that are associated with early phases of virus-host interplay as a therapeutic strategy

Brokering to Disrupt Power: How to Leverage Brokering Practices to Support Equity Outcomes

Brokers can play crucial roles in identifying, making visible, and breaking down power structures for youth. In this brief, we discuss how brokers may directly contribute to breaking down or sustaining power inequalities in access and opportunity.Spencer Foundation; New York Community Trust; Capital On

Application of highly sensitive saturation labeling to the analysis of differential protein expression in infected ticks from limited samples

<p>Abstract</p> <p>Background</p> <p>Ticks are vectors of pathogens that affect human and animal health worldwide. Proteomics and genomics studies of infected ticks are required to understand tick-pathogen interactions and identify potential vaccine antigens to control pathogen transmission. One of the limitations for proteomics research in ticks is the amount of protein that can be obtained from these organisms. In the work reported here, individual naturally-infected and uninfected <it>Rhipicephalus </it>spp. ticks were processed using a method that permits simultaneous extraction of DNA, RNA and proteins. This approach allowed using DNA to determine pathogen infection, protein for proteomics studies and RNA to characterize mRNA levels for some of the differentially expressed proteins. Differential protein expression in response to natural infection with different pathogens was characterized by two-dimensional (2-D) differential in gel electrophoresis (DIGE) saturation labeling in combination with mass spectrometry analysis. To our knowledge, this is the first report of the application of DIGE saturation labeling to study tick proteins.</p> <p>Results</p> <p>Questing and feeding <it>Rhipicephalus </it>spp. adult ticks were collected in 27 farms located in different Sicilian regions. From 300 collected ticks, only 16 were found to be infected: <it>R. sanguineus </it>with <it>Rickettsia conorii </it>and <it>Ehrlichia canis</it>; <it>R. bursa </it>with <it>Theileria annulata</it>; and <it>R. turanicus </it>with <it>Anaplasma ovis</it>. The proteomic analysis conducted from a limited amount of proteins allowed the identification of host, pathogen and tick proteins differentially expressed as a consequence of infection.</p> <p>Conclusion</p> <p>These results showed that DIGE saturation labeling is a powerful technology for proteomics studies in small number of ticks and provided new information about the effect of pathogen infection in ticks.</p

Different spectroscopic behavior of coupled and freestanding monolayer graphene deposited by CVD on Cu foil

The growth of graphene on copper foil has been performed, following the well-known low-pressure chemical vapor (LP-CVD) procedure. The as-deposited monolayer graphene clearly exhibits two different coupling behaviors with the metal substrate, as demonstrated by visual microscopic investigation and by other experimental techniques, like Scanning Electron Microscopy (SEM) and micro-Raman spectroscopy. The single graphene sheet shows both large areas where it is coupled to the metal substrate and others where it exhibits freestanding-like characteristics. This phenomenology appears to be related to oxidation of the copper surface. In addition, we demonstrate the possibility to induce a variation of the coupling state by visible-light irradiation above a proper power threshold. The resulting change of the coupling with the metal substrate is associated to a local variation of the work function. Applications in high-performance electronic devices can be suitably tailored by optical methods and, in principle, by any local probe producing "hot spots" such as Scanning Tunneling Microscopy (STM) tips and electron beams.</p