Efficacy and Safety of Axiostat® Hemostatic Dressing in Aiding Manual Compression Closure of the Femoral Arterial Access Site in Patients Undergoing Endovascular Treatments: A Preliminary Clinical Experience in Two Centers

Background: Hemostasis of the femoral arterial access site by manual compression or a vascular closure device is critical to the safe completion of any endovascular procedure. Previous investigations evaluated the hemostatic efficacy at the radial access site of some chitosan-based hemostatic pads. This study aims to assess the efficacy and safety of a new chitosan-based hemostatic dressing, namely Axiostat®, in aiding manual compression closure of the femoral arterial access site in patients undergoing endovascular treatments. Furthermore, the outcomes were compared with evidence on manual compression alone and vascular closure devices. Methods: This investigation is a two-center retrospective analysis of 120 consecutive patients who had undergone, from July 2022 to February 2023, manual compression closure of the femoral arterial access site aided by the Axiostat® hemostatic dressing. Endovascular procedures performed with introducer sheaths ranging from 4 Fr to 8 Fr were evaluated. Results: Primary technical success was achieved in 110 (91.7%) patients, with adequate hemostasis obtained in all cases of prolonged manual compression requirements. The mean time-to-hemostasis and time-to-ambulation were 8.9 (±3.9) and 462 (±199) minutes, respectively. Clinical success was achieved in 113 (94.2%) patients, with bleeding-related complications noted in 7 (5.8%) patients. Conclusions: Manual compression aided by the Axiostat® hemostatic dressing is effective and safe in achieving hemostasis of the femoral arterial access site in patients undergoing endovascular treatment with a 4–8 Fr introducer sheath

Discovery and Preliminary Characterization of Translational Modulators that Impair the Binding of eIF6 to 60S Ribosomal Subunits

Eukaryotic initiation factor 6 (eIF6) is necessary for the nucleolar biogenesis of 60S ribosomes. However, most of eIF6 resides in the cytoplasm, where it acts as an initiation factor. eIF6 is necessary for maximal protein synthesis downstream of growth factor stimulation. eIF6 is an antiassociation factor that binds 60S subunits, in turn preventing premature 40S joining and thus the formation of inactive 80S subunits. It is widely thought that eIF6 antiassociation activity is critical for its function. Here, we exploited and improved our assay for eIF6 binding to ribosomes (iRIA) in order to screen for modulators of eIF6 binding to the 60S. Three compounds, eIFsixty-1 (clofazimine), eIFsixty-4, and eIFsixty-6 were identified and characterized. All three inhibit the binding of eIF6 to the 60S in the micromolar range. eIFsixty-4 robustly inhibits cell growth, whereas eIFsixty-1 and eIFsixty-6 might have dose- and cell-specific effects. Puromycin labeling shows that eIF6ixty-4 is a strong global translational inhibitor, whereas the other two are mild modulators. Polysome profiling and RT-qPCR show that all three inhibitors reduce the specific translation of well-known eIF6 targets. In contrast, none of them affect the nucleolar localization of eIF6. These data provide proof of principle that the generation of eIF6 translational modulators is feasible

Direct and high throughput (HT) interactions on the ribosomal surface by iRIA

Ribosomes function as platforms for binding of other molecules, but technologies for studying this process are lacking. Therefore we developed iRIA (in vitro Ribosomes Interaction Assay). In approach I, Artemia salina ribosomes spotted on solid phase are used for binding picomoles of analytes; in approach II, cellular extracts allow the measurement of ribosome activity in different conditions. We apply the method to analyze several features of eIF6 binding to 60S subunits. By approach I, we show that the off-rate of eIF6 from preribosomes is slower than from mature ribosomes and that its binding to mature 60S occurs in the nM affinity range. By approach II we show that eIF6 binding sites on 60S are increased with mild eIF6 depletion and decreased in cells that are devoid of SBDS, a ribosomal factor necessary for 60S maturation and involved in Swachman Diamond syndrome. We show binding conditions to immobilized ribosomes adaptable to HT and quantify free ribosomes in cell extracts. In conclusion, we suggest that iRIA will greatly facilitate the study of interactions on the ribosomal surface

Dual-Layer Spectral CT as Innovative Imaging Guidance in Lung Biopsies: Could Color-Coded Z-Effective Images Allow More Diagnostic Samplings and Biomarkers Information?

The aim of the study was to try to obtain more information on diagnostic samplings and biomarkers using dual-layer spectral CT in lung biopsies. Lung biopsies were performed by merging images obtained with CBCT with those from spectral CT to use them as functional guidance, experimenting with double sampling to determine the difference between the area with a higher Z-effective number and that with a lower Z-effective number. Ten patients with large lung lesions on spectral CT were selected and underwent percutaneous transthoracic lung mass biopsy. Technical success was calculated. The percentage of neoplastic, inflammatory, fibrotic, necrotic cells, or non-neoplastic lung parenchyma was reported. The possibility of carrying out immunohistochemical or molecular biology investigations was analyzed. All lesions were results malignant in 10/10 samples in the Zmax areas; in the Zmin areas, malignant cells were found in 7/10 samples. Technical success was achieved in 100% of cases for Zmax sampling and in 70% for Zmin sampling (p-value: 0.2105). The biomolecular profile was detected in 9/10 (90%) cases in Zmax areas, while in 4/10 (40%) cases in Zmin areas (p-value: 0.0573). The advantage of Z-effective imaging would be to identify a region of the lesion that is highly vascularized and probably richer in neoplastic cells, thus decreasing the risk of obtaining a non-diagnostic biopsy sample

Ligand-induced perturbation of the HIF-2α:ARNT dimer dynamics

Hypoxia inducible factors (HIFs) are transcription factors belonging to the basic helix−loop−helix 28 PER-ARNT-SIM (bHLH-PAS) protein family with a role in sensing oxygen levels in the cell. 29 Under hypoxia, the HIF- degradation pathway is blocked and dimerization with the aryl 30 hydrocarbon receptor nuclear translocator (ARNT) makes HIF- transcriptionally active. Due to the 31 common hypoxic environment of tumors, inhibition of this mechanism by destabilization of HIF- 32 α:ARNT dimerization has been proposed as a promising therapeutic strategy. Following the 33 discovery of a druggable cavity within the PAS-B domain of HIF-2α, research efforts have been 34 directed to identify artificial ligands that can impair heterodimerization. Although the 35 crystallographic structures of the HIF-2α:ARNT complex have elucidated the dimer architecture 36 and the 0X3-inhibitor placement within the HIF-2α PAS-B, unveiling the inhibition mechanism 37 requires investigation of how ligand-induced perturbations could dynamically propagate through the 38 structure and affect dimerization. To this end, we compared evolutionary features, intrinsic 39 dynamics and energetic properties of the dimerization interfaces of HIF-2α:ARNT in both the apo 40 and holo forms. Residue conservation analysis highlighted inter-domain connecting elements that 41 have a role in dimerization. Analysis of domain contributions to the dimerization energy 42 demonstrated the importance of bHLH and PAS-A of both partners and of HIF-2α PAS-B domain 43 in dimer stabilization. Among quaternary structure oscillations revealed by Molecular Dynamics 44 simulations, the hinge-bending motion of the ARNT PAS-B domain around the flexible PAS45 A/PAS-B linker supports a general model for ARNT dimerization in different heterodimers. 46 Comparison of the HIF-2α:ARNT dynamics in the apo and 0X3-bound forms indicated a model of 47 inhibition where the HIF-2α-PAS-B interfaces are destabilised as a result of water-bridged ligand48 protein interactions and these local effects allosterically propagate to perturb the correlated motions 49 of the domains and inter-domain communication. These findings will guide the design of improved 50 inhibitors to contrast cell survival in tumor masses

Potential pro-inflammatory action of resveratrol in vascular smooth muscle cells from normal and diabetic rats

BACKGROUND AND AIM: Based on the reported cardioprotective effects of resveratrol, a polyphenolic antioxidant abundant in grapes that binds to estrogen receptors, and the well-characterized anti-inflammatory properties of 17beta-estradiol, the effects of resveratrol on the functional expression of inflammatory enzymes were assessed in vascular smooth muscle cells (SMC) from normoglycaemic and streptozotocin-diabetic rats. METHODS AND RESULTS: SMC were isolated from the aorta four weeks after treating rats with streptozotocin or its vehicle. In SMC exposed to a cytokine mixture for 24h, unexpectedly, treatment with resveratrol (0.1-100microM) as well as the structurally related isoflavone genistein (1nM-1microM) enhanced expression of inducible NO synthase (iNOS). Genistein failed to mimic the elevated iNOS activity induced by resveratrol. Inhibition of estrogen receptors by the pure antiestrogen ICI 182,780 reversed the action of resveratrol on iNOS. In addition, resveratrol failed to alter cyclooxygenase-2 protein levels but reduced the accumulation of prostaglandin E(2) in the culture medium of SMC from normoglycaemic, but not diabetic rats. CONCLUSIONS: These results indicate that resveratrol, at concentrations approaching putative peak plasma levels in vivo, exhibited no anti-inflammatory properties in vascular SMC from normal and diabetic rats. By contrast, resveratrol displayed a potential pro-inflammatory activity in settings of vascular inflammatio