34 research outputs found

    Hybrid Revascularization for Extensive Iliofemoral Occlusive Disease

    Get PDF
    Background: Total occlusion of the iliac-femoral tract can cause a variety of life-limiting symp-toms ranging from mild claudication to chronic limb-threatening ischemia. Efforts should be made to revascularize the symptomatic ischemic limb. Currently there are different options in the vascular surgeon's armamentarium to achieve this. The aim of the study was to verify the feasibility and outcomes of inflow hybrid revascularizations combining femoral endarterectomy and recanalization of iliac atherosclerotic occlusion. Methods: A retrospective review was conducted of all hybrid revascularizations involving femoral endarterectomy and endovascular treatment of iliac occlusion. The operations were per-formed in Helsinki University Hospital between January 2013 and December 2018. First, infor-mation about patients' baseline characteristics, indications and details of surgery and technical/ hemodynamic success, and complications and mortality were obtained from the vascular regis-try and patients records. Secondarily, a prospective assessment of mid-term patency was per-formed through follow-up in November 2019. Immediate technical success, 30-day mortality, complications, and patency were considered major outcomes. Hemodynamic improvement, amputation rate, and overall mortality were also assessed.Results: One hundred sixty three iliofemoral occlusions were performed on 147 patients during the period studied. Six patients (3.6%) had infrarenal aortic occlusion, 86 (52.7%) had common iliac, and 128 (78.5%) had external iliac artery occlusion. Technical success rate was 88.3% (n = 144 occlusions recanalized). Primary technical success was somewhat lower in lesions > 90 mm (87.1%) compared to lesions shorter than 90 mm (95.7%; c2 P = 0.06). Iliac stent was deployed in 141 (94.6%) cases, 51 (34.3%) of which were covered stents. Significant resid-ual stenosis remained in 1.2% of cases. Median operative time was 4 hr 34 min (interquartile range 2 hr 43 min) and median estimated blood loss was 743 mL (interquartile range 500 mL). Five patients (3.0%) developed a deep groin infection and 12 (8.1%) suffered any ma-jor cardiovascular event or stroke perioperatively. Primary patency at 30 day, 6 months, 1 year, and 2 years was 98.7%, 98.1%, 96.6%, and 93.7%, respectively. Hemodynamic success was documented in 107 patients (73%). By the end of the follow-up, 7 iliofemoral tracts (11.1%) reoc-cluded, 2 limbs (1.2%) required amputation, and 50 patients (3.0%) died. Conclusions: Good immediate success rate and mid-term patency can be achieved by hybrid revascularization of iliofemoral occlusions. Careful patient selection is mandatory because this pop-ulation often suffers from universal atherosclerosis. The involvement of the aorta represents a sig-nificant determinant of worse long-term patency, although it did not preclude technical success.Peer reviewe

    Product integrals II: Contour integrals

    Get PDF
    AbstractThis paper continues the joint work of the authors begun in the article “On Strong Product Integration” [J. Functional Analysis, submitted]. We consider product integrals along contours; the point of view and development is analogous to the usual complex variable theory of ordinary contour integrals. Our main results are Theorem 2.3 (homotopy invariance of product integrals, an analog of Cauchy's integral theorem) and Theorem 3.4 (an analog of Cauchy's integral formula or the residue theorem)

    USP7 and VCP define the SUMO/Ubiquitin landscape at the DNA replication fork

    Get PDF
    The AAA+ ATPase VCP regulates the extraction of SUMO and ubiquitin-modified DNA replication factors from chromatin. We have previously described that active DNA synthesis is associated with a SUMO-high/ubiquitin-low environment governed by the deubiquitylase USP7. Here, we unveil a functional cooperation between USP7 and VCP in DNA replication, which is conserved from Caenorhabditis elegans to mammals. The role of VCP in chromatin is defined by its cofactor FAF1, which facilitates the extraction of SUMOylated and ubiquitylated proteins that accumulate after the block of DNA replication in the absence of USP7. The inactivation of USP7 and FAF1 is synthetically lethal both in C. elegans and mammalian cells. In addition, USP7 and VCP inhibitors display synergistic toxicity supporting a functional link between deubiquitylation and extraction of chromatin-bound proteins. Our results suggest that USP7 and VCPFAF1 facilitate DNA replication by controlling the balance of SUMO/Ubiquitin-modified DNA replication factors on chromatinMINECO (BFU2014-55168-JIN; RTI2018-093485-B-I00) and a Ramo´ n y Cajal Fellowship from MINECO (RYC-2016-20705), co-funded by European Regional Development Funds (FEDER) to E.L.; by grants from the Spanish Ministry of Science, Innovation and Universities (RTI2018-102204-B-I00, co-financed with European FEDER funds) and the European Research Council (ERC-617840) to O.F.-C.; fellowships from Fundacion Ramón Areces-UAM and La Caixa Foundation to P.V. (LCF/BQ/ES18/11670008

    The Multivalency of the glucocorticoid receptor ligand-binding domain explains its manifold physiological activities

    Full text link
    The glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor that controls metabolic and homeostatic processes essential for life. Although numerous crystal structures of the GR ligand-binding domain (GR-LBD) have been reported, the functional oligomeric state of the full-length receptor, which is essential for its transcriptional activity, remains disputed. Here we present five new crystal structures of agonist-bound GR-LBD, along with a thorough analysis of previous structural work. We identify four distinct homodimerization interfaces on the GR-LBD surface, which can associate into 20 topologically different homodimers. Biologically relevant homodimers were identified by studying a battery of GR point mutants including crosslinking assays in solution, quantitative fluorescence microscopy in living cells, and transcriptomic analyses. Our results highlight the relevance of non-canonical dimerization modes for GR, especially of contacts made by loop L1-3 residues such as Tyr545. Our work illustrates the unique flexibility of GR's LBD and suggests different dimeric conformations within cells. In addition, we unveil pathophysiologically relevant quaternary assemblies of the receptor with important implications for glucocorticoid action and drug design

    Impaired Condensin Complex and Aurora B kinase underlie mitotic and chromosomal defects in hyperdiploid B-cell ALL

    Get PDF
    B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric cancer, and high-hyperdiploidy (HyperD) identifies the most common subtype of pediatric B-ALL. Despite HyperD is an initiating oncogenic event affiliated to childhood B-ALL, the mitotic and chromosomal defects associated to HyperD B-ALL (HyperD-ALL) remain poorly characterized. Here, we have used 54 primary pediatric B-ALL samples to characterize the cellular-molecular mechanisms underlying the mitotic/chromosome defects predicated to be early pathogenic contributors in HyperD-ALL. We report that HyperD-ALL blasts are low proliferative and show a delay in early mitosis at prometaphase, associated to chromosome alignment defects at the metaphase plate leading to robust chromosome segregation defects and non-modal karyotypes. Mechanistically, biochemical, functional and mass-spectrometry assays revealed that condensin complex is impaired in HyperD-ALL cells, leading to chromosome hypocondensation, loss of centromere stiffness and mis-localization of the chromosome passenger complex proteins Aurora B Kinase (AURKB) and Survivin in early mitosis. HyperD-ALL cells show chromatid cohesion defects and impaired spindle assembly checkpoint (SAC) thus undergoing mitotic slippage due to defective AURKB and impaired SAC activity, downstream of condensin complex defects. Chromosome structure/condensation defects and hyperdiploidy were reproduced in healthy CD34+ stem/progenitor cells upon inhibition of AURKB and/or SAC. Collectively, hyperdiploid B-ALL is associated to defective condensin complex, AURKB and SAC

    Chromatin regulation by Histone H4 acetylation at Lysine 16 during cell death and differentiation in the myeloid compartment

    Get PDF
    Histone H4 acetylation at Lysine 16 (H4K16ac) is a key epigenetic mark involved in gene regulation, DNA repair and chromatin remodeling, and though it is known to be essential for embryonic development, its role during adult life is still poorly understood. Here we show that this lysine is massively hyperacetylated in peripheral neutrophils. Genome-wide mapping of H4K16ac in terminally differentiated blood cells, along with functional experiments, supported a role for this histone post-translational modification in the regulation of cell differentiation and apoptosis in the hematopoietic system. Furthermore, in neutrophils, H4K16ac was enriched at specific DNA repeats. These DNA regions presented an accessible chromatin conformation and were associated with the cleavage sites that generate the 50 kb DNA fragments during the first stages of programmed cell death. Our results thus suggest that H4K16ac plays a dual role in myeloid cells as it not only regulates differentiation and apoptosis, but it also exhibits a non-canonical structural role in poising chromatin for cleavage at an early stage of neutrophil cell death

    Effects of intubation timing in patients with COVID-19 throughout the four waves of the pandemic : a matched analysis

    Get PDF
    The primary aim of our study was to investigate the association between intubation timing and hospital mortality in critically ill patients with COVID-19-associated respiratory failure. We also analysed both the impact of such timing throughout the first four pandemic waves and the influence of prior non-invasive respiratory support on outcomes. This is a secondary analysis of a multicentre, observational and prospective cohort study that included all consecutive patients undergoing invasive mechanical ventilation due to COVID-19 from across 58 Spanish intensive care units (ICU) participating in the CIBERESUCICOVID project. The study period was between 29 February 2020 and 31 August 2021. Early intubation was defined as that occurring within the first 24 h of intensive care unit (ICU) admission. Propensity score (PS) matching was used to achieve balance across baseline variables between the early intubation cohort and those patients who were intubated after the first 24 h of ICU admission. Differences in outcomes between early and delayed intubation were also assessed. We performed sensitivity analyses to consider a different timepoint (48 h from ICU admission) for early and delayed intubation. Of the 2725 patients who received invasive mechanical ventilation, a total of 614 matched patients were included in the analysis (307 for each group). In the unmatched population, there were no differences in mortality between the early and delayed groups. After PS matching, patients with delayed intubation presented higher hospital mortality (27.3% versus 37.1%, p =0.01), ICU mortality (25.7% versus 36.1%, p=0.007) and 90-day mortality (30.9% versus 40.2%, p=0.02) when compared to the early intubation group. Very similar findings were observed when we used a 48-hour timepoint for early or delayed intubation. The use of early intubation decreased after the first wave of the pandemic (72%, 49%, 46% and 45% in the first, second, third and fourth wave, respectively; first versus second, third and fourth waves p<0.001). In both the main and sensitivity analyses, hospital mortality was lower in patients receiving high-flow nasal cannula (n=294) who were intubated earlier. The subgroup of patients undergoing NIV (n=214) before intubation showed higher mortality when delayed intubation was set as that occurring after 48 h from ICU admission, but not when after 24 h. In patients with COVID-19 requiring invasive mechanical ventilation, delayed intubation was associated with a higher risk of hospital mortality. The use of early intubation significantly decreased throughout the course of the pandemic. Benefits of such an approach occurred more notably in patients who had received high-flow nasal cannul

    The multivalency of the glucocorticoid receptor ligand-binding domain explains its manifold physiological activities

    Get PDF
    20 páginas, 7 figurasThe glucocorticoid receptor (GR) is a ubiquitously expressed transcription factor that controls metabolic and homeostatic processes essential for life. Although numerous crystal structures of the GR ligand-binding domain (GR-LBD) have been reported, the functional oligomeric state of the full-length receptor, which is essential for its transcriptional activity, remains disputed. Here we present five new crystal structures of agonist-bound GR-LBD, along with a thorough analysis of previous structural work. We identify four distinct homodimerization interfaces on the GR-LBD surface, which can associate into 20 topologically different homodimers. Biologically relevant homodimers were identified by studying a battery of GR point mutants including crosslinking assays in solution, quantitative fluorescence microscopy in living cells, and transcriptomic analyses. Our results highlight the relevance of non-canonical dimerization modes for GR, especially of contacts made by loop L1-3 residues such as Tyr545. Our work illustrates the unique flexibility of GR's LBD and suggests different dimeric conformations within cells. In addition, we unveil pathophysiologically relevant quaternary assemblies of the receptor with important implications for glucocorticoid action and drug designE.E.-P. thanks the generosity of the Gemma E. Carretero Fund; MINECO [BFU2017-86906-R, SAF2017-71878-REDT, SAF2015-71878-REDT to E.E.-P., RTI2018-101500-B-I00 to P.F.-P., RTI2018-096735-B-100 to A.R.M., PID2019-110167RB-I00 to J.F.-R., SAF2017-89510-R to A.V.F. and C.C.]; G.L.H thanks the NIH Intramural Research Program; D.M.P was supported by CONICET. Funding for open access charge: Spanish Ministry of Science (MINECO).Peer reviewe
    corecore