1,489 research outputs found

    Identification of novel 2-benzoxazolinone derivatives with specific inhibitory activity against the HIV-1 nucleocapsid protein

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    In this report, we present a new benzoxazole derivative endowed with inhibitory activity against the HIV-1 nucleocapsid protein (NC). NC is a 55-residue basic protein with nucleic acid chaperone properties, which has emerged as a novel and potential pharmacological target against HIV-1. In the pursuit of novel NC-inhibitor chemotypes, we performed virtual screening and in vitro biological evaluation of a large library of chemical entities. We found that compounds sharing a benzoxazolinone moiety displayed putative inhibitory properties, which we further investigated by considering a series of chemical analogues. This approach provided valuable information on the structure-activity relationships of these compounds and, in the process, demonstrated that their anti-NC activity could be finely tuned by the addition of specific substituents to the initial benzoxazolinone scaffold. This study represents the starting point for the possible development of a new class of antiretroviral agents targeting the HIV-1 NC protein

    Development of a Cell-Based Immunodetection Assay for Simultaneous Screening of Antiviral Compounds Inhibiting Zika and Dengue Virus Replication:

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    Practical cell-based assays can accelerate anti-Zika (ZIKV) and anti-dengue (DENV) virus drug discovery. We developed an immunodetection assay (IA), using a pan-flaviviral monoclonal antibody recognizing a conserved envelope domain. The final protocol includes a direct virus yield reduction assay (YRA) carried out in the human Huh7 cell line, followed by transfer of the supernatant to a secondary Huh7 culture to characterize late antiviral effects. Sofosbuvir and ribavirin were used to validate the assay, while celgosivir was used to evaluate the ability to discriminate between early and late antiviral activity. In the direct YRA, at 100, 50, and 25 TCID50, sofosbuvir IC50 values were 5.0 ± 1.5, 2.7 ± 0.5, 2.5 ± 1.1 ”M against ZIKV and 16.6 ± 2.8, 4.6 ± 1.4, 2.6 ± 2.2 ”M against DENV; ribavirin IC50 values were 6.8 ± 4.0, 3.8 ± 0.6, 4.5 ± 1.4 ”M against ZIKV and 17.3 ± 4.6, 7.6 ± 1.2, 4.1 ± 2.3 ”M against DENV. Sofosbuvir and ribavirin IC50 values determined in the secondary YRA were reproducible and comparable with those obtained by direct YRA and plaque reduction assay (PRA). In agreement with the proposed mechanism of late action, celgosivir was active against DENV only in the secondary YRA (IC50 11.0 ± 1.0 ”M) and in PRA (IC50 10.1 ± 1.1 ”M). The assay format overcomes relevant limitations of the gold standard PRA, allowing concurrent analysis of candidate antiviral compounds against different viruses and providing preliminary information about early versus late antiviral activity

    Microchemical and microscopic characterization of the pictorial quality of egg-tempera polyptych, late 14th century, Florence, Italy

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    This paper explores the added value of micro-chemical and microscopic approaches to gather scientific evidence that can technically explain the pictorial quality of an egg-tempera painting, and underpin assessments that otherwise would be based on naked eye observations only. Demonstration is here provided via the interdisciplinary investigation of the original technique used by Giovanni del Biondo in the polyptych Annunciation and Saints (1385 ca), Galleria dell'Accademia, Florence, Italy. The exquisite surface appearance makes this panel painting remarkable compared to artworks by coeval artists. Imaging techniques (UV, IR and IR false color), non-invasive single spot techniques (XRF and FORS spectrometry) and analytical investigations on eight selected micro-samples (ATR-FTIR, GC/MS and Py/GC–MS, ESEM-EDS) were combined to retrieve the palette and identify organic binding media and a superficial coating layer. Stratigraphic and micro-chemical data confirmed the use of a relatively simple egg-tempera technique applied on a ground made of gypsum mixed with animal glue, without complex stratigraphic superimposition of preparation and pictorial layers. Various pigments were identified, among which is the precious lapis lazuli. While Py/GC–MS highlight that the coating is made of dammar resin and honey mixed with animal glue, the results allow us to state that the painting was not intentionally varnished by Giovanni del Biondo. These outcomes shed a new light on the technical knowledge of this polyptych, and prove how challenging is the attempt to categorize egg-tempera recipes used by ancient painters at the turn of the 14th century

    External quality assessment of HIV-1 DNA quantification assays used in the clinical setting in Italy

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    none18no: Total cell-associated HIV-1 DNA is a surrogate marker of the HIV-1 reservoir, however, certified systems for its quantification are not available. The Italian HIV DNA Network was launched to validate HIV-1 DNA quantification methods in use at University and Hospital labs. A quality control panel including HIV-1 DNA standards, reconstructed blood samples (RBSs) and DNA from different HIV-1 subtypes was blindly tested by 12 participating labs by quantitative real-time PCR (n = 6), droplet digital PCR (n = 3) or both (n = 3). The median 95% hit rate was 4.6 (3.7-5.5) copies per test and linearity in the tested range was excellent (R2 = 1.000 [1.000-1.000]). The median values obtained across labs were 3,370 (2,287-4,245), 445 (299-498), 59 (40-81) and 7 (6-11) HIV-1 DNA copies, for the 3,584, 448, 56 and 7-copy standards, respectively. With RBSs, measured values were within twofold with respect to the median in two thirds of cases. HIV-1 subtypes were missed (CRF01_AE by 3 labs) or underestimated by > 1 log (subtypes A, C, D, F by one lab; CRF01_AE by one lab; CRF02_AG by one lab). The overall performance was excellent with HIV-1 DNA standards, however detection of different HIV-1 subtypes must be improved.openVicenti, Ilaria; Dragoni, Filippo; Giannini, Alessia; Casabianca, Anna; Lombardi, Francesca; Di Sante, Laura; Turriziani, Ombretta; Racca, Sara; Paolucci, Stefania; Lai, Alessia; Bon, Isabella; Abbate, Isabella; Rozera, Gabriella; Belmonti, Simone; Scutari, Rossana; Alteri, Claudia; Saladini, Francesco; Zazzi, MaurizioVicenti, Ilaria; Dragoni, Filippo; Giannini, Alessia; Casabianca, Anna; Lombardi, Francesca; Di Sante, Laura; Turriziani, Ombretta; Racca, Sara; Paolucci, Stefania; Lai, Alessia; Bon, Isabella; Abbate, Isabella; Rozera, Gabriella; Belmonti, Simone; Scutari, Rossana; Alteri, Claudia; Saladini, Francesco; Zazzi, Maurizi

    Analysis of tapered front-coupling X-ray waveguides.

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    The coupling and propagation of electromagnetic waves through planar X-ray waveguides (WG) with vacuum gap and Si claddings are analyzed in detail, starting from the source and ending at the detector. The general case of linearly tapered WGs (i.e. with the entrance aperture different from the exit one) is considered. Different kinds of sources, i.e. synchrotron radiation and laboratory desk-top sources, have been considered, with the former providing a fully coherent incoming beam and the latter partially coherent beams. It is demonstrated that useful information about the parameters of the WG can be derived, comparing experimental results with computer simulation based on analytical solutions of the Helmholtz equation which take into account the amplitude and phase matching between the standing waves created in front of the WG, and the resonance modes propagating into the WG

    Continuous Environmental Changes May Enhance Topographic Memory Skills. Evidence From L’Aquila Earthquake-Exposed Survivors

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    Exposure to environmental contextual changes, such as those occurring after an earthquake, requires individuals to learn novel routes around their environment, landmarks and spatial layout. In this study, we aimed to uncover whether contextual changes that occurred after the 2009 L’Aquila earthquake affected topographic memory in exposed survivors. We hypothesized that individuals exposed to environmental changes—individuals living in L’Aquila before, during and after the earthquake (hereafter called exposed participants, EPs)—improved their topographic memory skills compared with non-exposed participants (NEPs) who moved to L’Aquila after the earthquake, as only EPs had to modify their previous cognitive map of L’Aquila. We also hypothesized that memory improvement was selective for the navigational space and did not generalize across other spatial and verbal domains. To test these hypotheses, we compared the topographic and spatial memory skills of 56 EPs without post-traumatic stress disorder (PTSD) symptoms to the skills of 47 NEPs using the Walking Corsi Test (WalCT; memory test in the navigational space) and the Corsi Block-Tapping Test (CBT; visuospatial memory test in the reaching space); EPs and NEPs were matched for gender, education and general navigational skills. A sub-group of participants also underwent the Rey-Auditory Verbal Learning Test (RAVLT; verbal memory test). The results showed that only EPs had better performances on topographic learning (TL) assessed using the WalCT rather than spatial learning assessed by the CBT. This outcome suggests the possibility that EPs specifically improved topographic memory. This effect may be due to continuous exposure to environmental changes that have required individuals to learn novel paths within the city and integrate novel information, such as “new towns,” into their pre-existing mental representation of the city. Implications and limitations of the study are discussed

    Years of life that could be saved from prevention of hepatocellular carcinoma

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    BACKGROUND: Hepatocellular carcinoma (HCC) causes premature death and loss of life expectancy worldwide. Its primary and secondary prevention can result in a significant number of years of life saved. AIM: To assess how many years of life are lost after HCC diagnosis. METHODS: Data from 5346 patients with first HCC diagnosis were used to estimate lifespan and number of years of life lost after tumour onset, using a semi-parametric extrapolation having as reference an age-, sex- and year-of-onset-matched population derived from national life tables. RESULTS: Between 1986 and 2014, HCC lead to an average of 11.5 years-of-life lost for each patient. The youngest age-quartile group (18-61 years) had the highest number of years-of-life lost, representing approximately 41% of the overall benefit obtainable from prevention. Advancements in HCC management have progressively reduced the number of years-of-life lost from 12.6 years in 1986-1999, to 10.7 in 2000-2006 and 7.4 years in 2007-2014. Currently, an HCC diagnosis when a single tumour <2 cm results in 3.7 years-of-life lost while the diagnosis when a single tumour 65 2 cm or 2/3 nodules still within the Milan criteria, results in 5.0 years-of-life lost, representing the loss of only approximately 5.5% and 7.2%, respectively, of the entire lifespan from birth. CONCLUSIONS: Hepatocellular carcinoma occurrence results in the loss of a considerable number of years-of-life, especially for younger patients. In recent years, the increased possibility of effectively treating this tumour has improved life expectancy, thus reducing years-of-life lost

    The influence of HIV infection on the natural history of hepatocellular carcinoma: results from a global multi-cohort study

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    Purpose. Conflicting evidence indicates HIV-seropositivity to influence the outcome of patients with hepatocellular carcinoma (HCC), a leading cause of mortality in people with HIV. We aimed to verify whether HIV affected the overall survival (OS) of patients with HCC independent of treatment and geographic origin. Patients and Methods: We designed an international multi-cohort study of HCC patients who did not receive any anticancer treatment accrued from four continents. We estimated the effect of HIV-seropositivity on patients’ OS while accounting for common prognostic factors and demographic characteristics in uni- and multi-variable models. Results: A total of 1588 patients were recruited, 132 of whom were HIV-positive. Most patients clustered within Barcelona Clinic Liver Cancer (BCLC) C/D criteria (n=1168, 74%), Child-Turcotte-Pugh (CTP) Class B (median score 7, IQR 3). At HCC diagnosis the majority of HIV-positive patients (n=65, 64%) had been on anti-retrovirals for a median duration of 8.3 years (IQR 8.59) and had median CD4+ cell counts of 256 (IQR 284) with undetectable HIV RNA (n=68, 52%). OS significantly reduced throughout BCLC stages 0-D (16, 12, 7.5, 3.1 and 3 months, p<0.001). Median OS of HIV-positive patients was half that of HIV-uninfected counterparts: 2.2 months, (bootstrap 95%CI 1.2-3.1) versus 4.1 months (95%CI 3.6-4.4). In adjusted analyses HIV-seropositivity increased the hazard of death by 24% (p=0.0333) independent of BCLC (p<0.0001), CTP (p<0.0001), alpha-fetoprotein (AFP) (p<0.0001), geographical origin (p<0.0001) and male gender (p=0.0016). Predictors of worse OS in HIV-positive patients included CTP (p=0.0071) and AFP (p<0.0001). Conclusions. Despite adequate antiretroviral treatment, HIV-seropositivity is associated with decreased survival in HCC independent of stage, anti-cancer treatment and geographical origin. Mechanistic studies investigating the immuno-biology of HIV-associated HCC are urgently required
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