145 research outputs found

    Acute Kidney Injury in Patients Undergoing Chronic Hepatitis C Virus Treatment With Ledipasvir/Sofosbuvir

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    Ledipasvir-sofosbuvir, a once-a-day, oral combination pill, was approved in 2014 for the treatment of chronic hepatitis C infection. Initial trials did not comment on nephrotoxicity; however, recent data suggest a risk of acute kidney injury (AKI) with the use of the medication. We assessed the rates of AKI in patients undergoing ledipasvir-sofosbuvir in a large, urban tertiary care center. This single-center retrospective observation study included all patients undergoing therapy from October 1, 2014, to October 1, 2015. Rates of AKI, defined by more than a 0.3 mg/dL increase in serum creatinine level, were calculated. Patients were followed 12 weeks after therapy to assess for sustained viral response as well as to assess for improvement of AKI after completion of therapy, defined by less than 0.2 mg/dL above baseline serum creatinine. In total, 197 patients were included in the final analysis who had completed ledipasvir-sofosbuvir therapy and completed laboratory values. Among the patients treated, 38 (19%) had AKI during therapy. An additional 4 (2%) had AKI at the end of therapy. Of the 38 patients who experienced AKI, 20 (53%) had improvement in serum creatinine to less than 0.2 mg/dL above their baseline. When comparing for chronic kidney disease (CKD) stage, those with CKD I or II experienced AKI 17% of the time compared with 47% of the time in CKD III or worse (P = 0.005). Conclusion: AKI was seen in nearly one-fifth of our patients, and patients with CKD stage III or worse are at increased risk. Although ledipasvir-sofosbuvir is generally safe in the general population, close monitoring of renal function is recommended

    Morphogenesis of myocardial trabeculae in the mouse embryo

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    Formation of trabeculae in the embryonic heart and the remodelling that occurs prior to birth is a conspicuous, but poorly understood, feature of vertebrate cardiogenesis. Mutations disrupting trabecular development in the mouse are frequently embryonic lethal, testifying to the importance of the trabeculae, and aberrant trabecular structure is associated with several human cardiac pathologies. Here, trabecular architecture in the developing mouse embryo has been analysed using high-resolution episcopic microscopy (HREM) and three-dimensional (3D) modelling. This study shows that at all stages from mid-gestation to birth, the ventricular trabeculae comprise a complex meshwork of myocardial strands. Such an arrangement defies conventional methods of measurement, and an approach based upon fractal algorithms has been used to provide an objective measure of trabecular complexity. The extent of trabeculation as it changes along the length of left and right ventricles has been quantified, and the changes that occur from formation of the four-chambered heart until shortly before birth have been mapped. This approach not only measures qualitative features evident from visual inspection of 3D models, but also detects subtle, consistent and regionally localised differences that distinguish each ventricle and its developmental stage. Finally, the combination of HREM imaging and fractal analysis has been applied to analyse changes in embryonic heart structure in a genetic mouse model in which trabeculation is deranged. It is shown that myocardial deletion of the Notch pathway component Mib1 (Mib1(flox/flox); cTnT-cre) results in a complex array of abnormalities affecting trabeculae and other parts of the heart.This work was supported by funding to TJM from the Medical Research Council (U117562103); to JCM by the Higher Education Funding Council for England; to JLdlP and GL by grants SAF2010-17555 and SAF2013-45543-R from the Spanish Ministry of Economy and Competitiveness (MINECO); and to GC by a research fellowship at the University College London Biomedical Research Centre from the UK National Institutes of Health Research Cardiometabolic Programme.S

    Phase I trial of oncolytic adenovirus-mediated cytotoxic and interleukin-12 gene therapy for the treatment of metastatic pancreatic cancer

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    The safety of oncolytic adenovirus-mediated suicide and interleukin-12 (IL 12) gene therapy was evaluated in metastatic pancreatic cancer patients. In this phase I study, a replication-competent adenovirus (Ad5-yCD/mutTK(SR39) rep-hIL-12) expressing yCD/mutTK(SR39) (yeast cytidine deaminase/mutant S39R HSV-1 thymidine kinase) and human IL-12 (IL 12) was injected into tumors of 12 subjects with metastatic pancreatic cancer (T2N0M1-T4N1M1) at escalating doses (1 × 10(11), 3 × 10(11), or 1 × 10(12) viral particles). Subjects received 5-fluorocytosine (5-FC) therapy for 7 days followed by chemotherapy (FOLFIRINOX or gemcitabine/albumin-bound paclitaxel) starting 21 days after adenovirus injection. The study endpoint was toxicity through day 21. Experimental endpoints included measurements of serum IL 12, interferon gamma (IFNG), and CXCL10 to assess immune system activation. Peripheral blood mononuclear cells and proliferation markers were analyzed by flow cytometry. Twelve patients received Ad5-yCD/mutTK(SR39) rep-hIL-12 and oral 5-FC. Approximately 94% of the 121 adverse events observed were grade 1/2 requiring no medical intervention. Ad5-yCD/mutTK(SR39) rep-hIL-12 DNA was detected in the blood of two patients. Elevated serum IL 12, IFNG, and CXCL10 levels were detected in 42%, 75%, and 92% of subjects, respectively. Analysis of immune cell populations indicated activation after Ad5-yCD/mutTK(SR39) rep-hIL-12 administration. The median survival of patients in the third cohort is 18.1 (range, 3.5-20.0) months. The study maximum tolerated dose (MTD) was not reached

    Risk factors associated with adenoma recurrence following cold snare endoscopic mucosal resection of polyps ≥ 20 mm: a retrospective chart review

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    Background and study aims: Cold snare endoscopic mucosal resection (EMR) is being increasingly utilized for non-pedunculated polyps ≥ 20 mm due to adverse events associated with use of cautery. Larger studies evaluating adenoma recurrence rate (ARR) and risk factors for recurrence following cold snare EMR of large polyps are lacking. The aim of this study was to define ARR for polyps ≥ 20 mm removed by cold snare EMR and to identify risk factors for recurrence. Patients and methods: A retrospective chart review of colon cold snare EMR procedures performed between January 2015 and July 2019 at a tertiary care medical center was performed. During this period, 310 non-pedunculated polyps ≥ 20 mm were excised using cold snare EMR with follow-up surveillance colonoscopy. Patient demographic data as well as polyp characteristics at the time of index and surveillance colonoscopy were collected and analyzed. Results: A total of 108 of 310 polyps (34.8 %) demonstrated adenoma recurrence at follow-up colonoscopy. Patients with a higher ARR were older ( P  = 0.008), had endoscopic clips placed at index procedure ( P  = 0.017), and were more likely to be Asian and African American ( P  = 0.02). ARR was higher in larger polyps ( P  \u3c 0.001), tubulovillous adenomas ( P  \u3c 0.001), and polyps with high-grade dysplasia ( P  = 0.003). Conclusions: Although cold snare EMR remains a feasible alternative to hot snare polypectomy for resection of non-pedunculated polyps ≥ 20 mm, endoscopists must also carefully consider factors associated with increased ARR when utilizing this technique

    Characteristics of a novel treatment system for linear accelerator–based stereotactic radiosurgery

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    The purpose of this study is to characterize the dosimetric properties and accuracy of a novel treatment platform (Edge radiosurgery system) for localizing and treating patients with frameless, image-guided stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). Initial measurements of various components of the system, such as a comprehensive assessment of the dosimetric properties of the flattening filter-free (FFF) beams for both high definition (HD120) MLC and conical cone-based treatment, positioning accuracy and beam attenuation of a six degree of freedom (6DoF) couch, treatment head leakage test, and integrated end-to-end accuracy tests, have been performed. The end-to-end test of the system was performed by CT imaging a phantom and registering hidden targets on the treatment couch to determine the localization accuracy of the optical surface monitoring system (OSMS), cone-beam CT (CBCT), and MV imaging systems, as well as the radiation isocenter targeting accuracy. The deviations between the percent depth-dose curves acquired on the new linac-based system (Edge), and the previously published machine with FFF beams (TrueBeam) beyond Dmax were within 1.0% for both energies. The maximum deviation of output factors between the Edge and TrueBeam was 1.6%. The optimized dosimetric leaf gap values, which were fitted using Eclipse dose calculations and measurements based on representative spine radiosurgery plans, were 0.700 mm and 1.000 mm, respectively. For the conical cones, 6X FFF has sharper penumbra ranging from 1.2–1.8 mm (80%-20%) and 1.9–3.8 mm (90%-10%) relative to 10X FFF, which has 1.2–2.2mm and 2.3–5.1mm, respectively. The relative attenuation measurements of the couch for PA, PA (rails-in), oblique, oblique (rails-out), oblique (rails-in) were: -2.0%, -2.5%, -15.6%, -2.5%, -5.0% for 6X FFF and -1.4%, -1.5%, -12.2%, -2.5%, -5.0% for 10X FFF, respectively, with a slight decrease in attenuation versus field size. The systematic deviation between the OSMS and CBCT was -0.4 ± 0.2 mm, 0.1± 0.3mm, and 0.0 ± 0.1 mm in the vertical, longitudinal, and lateral directions. The mean values and standard deviations of the average deviation and maximum deviation of the daily Winston-Lutz tests over three months are 0.20 ± 0.03 mm and 0.66 ± 0.18 mm, respectively. Initial testing of this novel system demonstrates the technology to be highly accurate and suitable for frameless, linac-based SRS and SBRT treatment

    Human pre-valvular endocardial cells derived from pluripotent stem cells recapitulate cardiac pathophysiological valvulogenesis

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    Genetically modified mice have advanced our understanding of valve development and disease. Yet, human pathophysiological valvulogenesis remains poorly understood. Here we report that, by combining single cell sequencing and in vivo approaches, a population of human pre-valvular endocardial cells (HPVCs) can be derived from pluripotent stem cells. HPVCs express gene patterns conforming to the E9.0 mouse atrio-ventricular canal (AVC) endocardium signature. HPVCs treated with BMP2, cultured on mouse AVC cushions, or transplanted into the AVC of embryonic mouse hearts, undergo endothelial-to-mesenchymal transition and express markers of valve interstitial cells of different valvular layers, demonstrating cell specificity. Extending this model to patient-specific induced pluripotent stem cells recapitulates features of mitral valve prolapse and identified dysregulation of the SHH pathway. Concurrently increased ECM secretion can be rescued by SHH inhibition, thus providing a putative therapeutic target. In summary, we report a human cell model of valvulogenesis that faithfully recapitulates valve disease in a dish.We thank the Leducq Fondation for supporting Tui Neri, and funding this research under the framework of the MITRAL network and for generously awarding us for the equipment of our cell imaging facility in the frame of their program “Equipement de Recherche et Plateformes Technologiques” (ERPT to M.P.), the Genopole at Evry and the Fondation de la recherche Medicale (grant DEQ20100318280) for supporting the laboratory of Michel Puceat. Part of this work in South Carolina University was conducted in a facility constructed with support from the National Institutes of Health, Grant Number C06 RR018823 from the Extramural Research Facilities Program of the National Center for Research Resources. Other funding sources: National Heart Lung and Blood Institute: RO1-HL33756 (R.R.M.), COBRE P20RR016434–07 (R.R.M., R.A. N.), P20RR016434–09S1 (R.R.M. and R.A.N.); American Heart Association: 11SDG5270006 (R.A.N.); National Science Foundation: EPS-0902795 (R.R.M. and R.A. N.); American Heart Association: 10SDG2630130 (A.C.Z.), NIH: P01HD032573 (A.C. Z.), NIH: U54 HL108460 (A.C.Z), NCATS: UL1TR000100 (A.C.Z.); EH was supported by a fellowship of the Ministere de la recherche et de l’éducation in France.TM-M was supported by a fellowship from the Fondation Foulon Delalande and the Leducq Foundation. P.v.V. was sponsored by a UC San Diego Cardiovascular Scholarship Award and a Postdoctoral Fellowship from the California Institute for Regenerative Medicine (CIRM) Interdisciplinary Stem Cell Training Program II. S.M.E. was funded by a grant from the National Heart, Lung, and Blood Institute (HL-117649). A.T. is supported by the National Heart, Lung, and Blood Institute (R01-HL134664).S

    Regeneration Changes in Tree Species Abundance, Diversity and Structure in Logged and Unlogged Subtropical Rainforest over a Thirty-Six-Year Period

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    The long-term effects of logging treatments on rainforest regeneration are difficult to quantify due to compounding interactions between natural dynamics, site characteristics and tree species. The aim of this study was to compare regeneration differences over a 36 year period in stands subjected to various levels of disturbance ranging from natural, through an increasing intensity of individual tree removal to intensive logging. Data for tree

    CSL–MAML-dependent Notch1 signaling controls T lineage–specific IL-7Rα gene expression in early human thymopoiesis and leukemia

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    Notch1 activation is essential for T-lineage specification of lymphomyeloid progenitors seeding the thymus. Progression along the T cell lineage further requires cooperative signaling provided by the interleukin 7 receptor (IL-7R), but the molecular mechanisms responsible for the dynamic and lineage-specific regulation of IL-7R during thymopoiesis are unknown. We show that active Notch1 binds to a conserved CSL-binding site in the human IL7R gene promoter and critically regulates IL7R transcription and IL-7R α chain (IL-7Rα) expression via the CSL–MAML complex. Defective Notch1 signaling selectively impaired IL-7Rα expression in T-lineage cells, but not B-lineage cells, and resulted in a compromised expansion of early human developing thymocytes, which was rescued upon ectopic IL-7Rα expression. The pathological implications of these findings are demonstrated by the regulation of IL-7Rα expression downstream of Notch1 in T cell leukemias. Thus, Notch1 controls early T cell development, in part by regulating the stage- and lineage-specific expression of IL-7Rα

    Conditional Ablation of Ezh2 in Murine Hearts Reveals Its Essential Roles in Endocardial Cushion Formation, Cardiomyocyte Proliferation and Survival

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    Ezh2 is a histone trimethyltransferase that silences genes mainly via catalyzing trimethylation of histone 3 lysine 27 (H3K27Me3). The role of Ezh2 as a regulator of gene silencing and cell proliferation in cancer development has been extensively investigated; however, its function in heart development during embryonic cardiogenesis has not been well studied. In the present study, we used a genetically modified mouse system in which Ezh2 was specifically ablated in the mouse heart. We identified a wide spectrum of cardiovascular malformations in the Ezh2 mutant mice, which collectively led to perinatal death. In the Ezh2 mutant heart, the endocardial cushions (ECs) were hypoplastic and the endothelial-to-mesenchymal transition (EMT) process was impaired. The hearts of Ezh2 mutant mice also exhibited decreased cardiomyocyte proliferation and increased apoptosis. We further identified that the Hey2 gene, which is important for cardiomyocyte proliferation and cardiac morphogenesis, is a downstream target of Ezh2. The regulation of Hey2 expression by Ezh2 may be independent of Notch signaling activity. Our work defines an indispensible role of the chromatin remodeling factor Ezh2 in normal cardiovascular development

    Msx1 and Msx2 are required for endothelial-mesenchymal transformation of the atrioventricular cushions and patterning of the atrioventricular myocardium

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    <p>Abstract</p> <p>Background</p> <p><it>Msx1 </it>and <it>Msx2</it>, which belong to the highly conserved <it>Nk </it>family of homeobox genes, display overlapping expression patterns and redundant functions in multiple tissues and organs during vertebrate development. <it>Msx1 </it>and <it>Msx2 </it>have well-documented roles in mediating epithelial-mesenchymal interactions during organogenesis. Given that both <it>Msx1 </it>and <it>Msx2 </it>are crucial downstream effectors of Bmp signaling, we investigated whether <it>Msx1 </it>and <it>Msx2 </it>are required for the Bmp-induced endothelial-mesenchymal transformation (EMT) during atrioventricular (AV) valve formation.</p> <p>Results</p> <p>While both <it>Msx1-/- </it>and <it>Msx2-/- </it>single homozygous mutant mice exhibited normal valve formation, we observed hypoplastic AV cushions and malformed AV valves in <it>Msx1-/-; Msx2-/- </it>mutants, indicating redundant functions of <it>Msx1 </it>and <it>Msx2 </it>during AV valve morphogenesis. In <it>Msx1/2 </it>null mutant AV cushions, we found decreased Bmp2/4 and <it>Notch1 </it>signaling as well as reduced expression of <it>Has2</it>, <it>NFATc1 </it>and <it>Notch1</it>, demonstrating impaired endocardial activation and EMT. Moreover, perturbed expression of chamber-specific genes <it>Anf</it>, <it>Tbx2</it>, <it>Hand1 </it>and <it>Hand2 </it>reveals mispatterning of the <it>Msx1/2 </it>double mutant myocardium and suggests functions of <it>Msx1 </it>and <it>Msx2 </it>in regulating myocardial signals required for remodelling AV valves and maintaining an undifferentiated state of the AV myocardium.</p> <p>Conclusion</p> <p>Our findings demonstrate redundant roles of <it>Msx1 </it>and <it>Msx2 </it>in regulating signals required for development of the AV myocardium and formation of the AV valves.</p
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