Publications by authors named "Michel d"

652 Publications

A pathogenic UFSP2 variant in an autosomal recessive form of pediatric neurodevelopmental anomalies and epilepsy.

Genet Med 2021 Jan 20. Epub 2021 Jan 20.

Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, TX, USA.

Purpose: Neurodevelopmental disabilities are common and genetically heterogeneous. We identified a homozygous variant in the gene encoding UFM1-specific peptidase 2 (UFSP2), which participates in the UFMylation pathway of protein modification. UFSP2 variants are implicated in autosomal dominant skeletal dysplasias, but not neurodevelopmental disorders. Homozygosity for the variant occurred in eight children from four South Asian families with neurodevelopmental delay and epilepsy. We describe the clinical consequences of this variant and its effect on UFMylation.

Methods: Exome sequencing was used to detect potentially pathogenic variants and identify shared regions of homozygosity. Immunoblotting assessed protein expression and post-translational modifications in patient-derived fibroblasts.

Results: The variant (c.344T>A; p.V115E) is rare and alters a conserved residue in UFSP2. Immunoblotting in patient-derived fibroblasts revealed reduced UFSP2 abundance and increased abundance of UFMylated targets, indicating the variant may impair de-UFMylation rather than UFMylation. Reconstituting patient-derived fibroblasts with wild-type UFSP2 reduced UFMylation marks. Analysis of UFSP2's structure indicated that variants observed in skeletal disorders localize to the catalytic domain, whereas V115 resides in an N-terminal domain possibly involved in substrate binding.

Conclusion: Different UFSP2 variants cause markedly different diseases, with homozygosity for V115E causing a severe syndrome of neurodevelopmental disability and epilepsy.
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http://dx.doi.org/10.1038/s41436-020-01071-zDOI Listing
January 2021

Combinatorial Drug Treatments Reveal Promising Anticytomegaloviral Profiles for Clinically Relevant Pharmaceutical Kinase Inhibitors (PKIs).

Int J Mol Sci 2021 Jan 8;22(2). Epub 2021 Jan 8.

Institute for Clinical and Molecular Virology, Friedrich-Alexander University of Erlangen-Nürnberg (FAU), Schlossgarten 4, 91054 Erlangen, Germany.

Human cytomegalovirus (HCMV) is a human pathogenic herpesvirus associated with a variety of clinical symptoms. Current antiviral therapy is not always effective, so that improved drug classes and drug-targeting strategies are needed. Particularly host-directed antivirals, including pharmaceutical kinase inhibitors (PKIs), may help to overcome problems of drug resistance. Here, we focused on utilizing a selection of clinically relevant PKIs and determined their anticytomegaloviral efficacies. Particularly, PKIs directed to host or viral cyclin-dependent kinases, i.e., abemaciclib, LDC4297 and maribavir, exerted promising profiles against human and murine cytomegaloviruses. The anti-HCMV in vitro activity of the approved anti-cancer drug abemaciclib was confirmed in vivo using our luciferase-based murine cytomegalovirus (MCMV) animal model in immunocompetent mice. To assess drug combinations, we applied the Bliss independence checkerboard and Loewe additivity fixed-dose assays in parallel. Results revealed that (i) both affirmative approaches provided valuable information on anti-CMV drug efficacies and interactions, (ii) the analyzed combinations comprised additive, synergistic or antagonistic drug interactions consistent with the drugs' antiviral mode-of-action, (iii) the selected PKIs, especially LDC4297, showed promising inhibitory profiles, not only against HCMV but also other α-, β- and γ-herpesviruses, and specifically, (iv) the combination treatment with LDC4297 and maribavir revealed a strong synergism against HCMV, which might open doors towards novel clinical options in the near future. Taken together, this study highlights the potential of therapeutic drug combinations of current developmental/preclinical PKIs.
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http://dx.doi.org/10.3390/ijms22020575DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7826512PMC
January 2021

Competing magnetic phases and fluctuation-driven scalar spin chirality in the kagome metal YMnSn.

Sci Adv 2020 Dec 18;6(51). Epub 2020 Dec 18.

Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030, USA.

Identification, understanding, and manipulation of novel magnetic textures are essential for the discovery of new quantum materials for future spin-based electronic devices. In particular, materials that manifest a large response to external stimuli such as a magnetic field are subject to intense investigation. Here, we study the kagome-net magnet YMnSn by magnetometry, transport, and neutron diffraction measurements combined with first-principles calculations. We identify a number of nontrivial magnetic phases, explain their microscopic nature, and demonstrate that one of them hosts a large topological Hall effect (THE). We propose a previously unidentified fluctuation-driven mechanism, which leads to the THE at elevated temperatures. This interesting physics comes from parametrically frustrated interplanar exchange interactions that trigger strong magnetic fluctuations. Our results pave a path to chiral spin textures, promising for novel spintronics.
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http://dx.doi.org/10.1126/sciadv.abe2680DOI Listing
December 2020

Characteristics and mechanisms to control a COVID-19 outbreak on a leukemia and stem cell transplantation unit.

Cancer Med 2021 01 12;10(1):237-246. Epub 2020 Dec 12.

Department of Internal Medicine, Diakonie Hospital Stuttgart, Stuttgart, Germany.

Immunosuppressed patients like patients with leukemia or lymphoma, but also patients after autologous or allogeneic stem cell transplantation are at particular risk for an infection with COVID-19. We describe a COVID-19 outbreak on our leukemia and stem cell transplantation unit (LSCT-Unit) originating from a patient with newly diagnosed acute myeloid leukemia. The patient was treated with intensive induction chemotherapy and we characterize the subsequent outbreak of COVID-19 on a LSCT-Unit. We describe the characteristics of the 36 contacts among the medical team, the results of their PCR and antibody tests and clinical aspects and features of infected employees. Of these 36 close contacts, 9 employees of the LSCT-Unit were infected and were tested positive by PCR and/or antibody-testing. 8/9 of them were symptomatic, 3/9 with severe, 5/9 with mild symptoms, and one person without symptoms. Due to stringent hygiene measures, the outbreak did not lead to infections of other patients despite ongoing clinical work. Moreover, we demonstrate that incubation period and clinical course of a COVID-19 infection in an immunosuppressed patient could be unusual compared to that of immunocompetent patients. Consistent PCR and antibody testing are helpful to understand, control, and prevent outbreaks. For the safety of health-care workers and patients alike, all employees wore FFP2 masks and were trained to adhere to several further safety guidelines. The implementation of rigorous hygiene measures is the key to controlling an outbreak and preventing infections of other patients.
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http://dx.doi.org/10.1002/cam4.3612DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7826490PMC
January 2021

Rapid, convenient and efficient kit-independent detection of SARS-CoV-2 RNA.

J Virol Methods 2020 12 3;286:113965. Epub 2020 Sep 3.

Department of Neurology, Ulm University, Ulm, Germany.

Pandemic SARS-CoV-2 infection has rapidly developed into a socioeconomic and humanitarian catastrophe. Basic principles to prevent SARS-CoV-2 transmission are social distancing, face masks, contact tracing and early detection of SARS-CoV-2. To meet these requirements, virtually unlimited test capacities delivering results in a rapid and reliable manner are a prerequisite. Here, we provide and validate such a rapid, convenient and efficient kit-independent detection of SARS-CoV-2 RNA, termed COVID-quick-DET. This straightforward method operates with simple proteinase K treatment and repetitive heating steps with a sensitivity of 94.6% in head-to-head comparisons with kit-based isolation methods. This result is supported by data obtained from serially diluted SARS-CoV-2 virus stocks. Given its cost- and time-effective operation, COVID-quick-DET might be best suited for countries with general shortage or temporary acute scarcity of resources and equipment.
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http://dx.doi.org/10.1016/j.jviromet.2020.113965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7468345PMC
December 2020

Miller-Fisher syndrome after COVID-19: neurochemical markers as an early sign of nervous system involvement.

Eur J Neurol 2020 11;27(11):2378-2380

Department of Neurology, Ulm University Hospital, Ulm, Germany.

Miller-Fisher syndrome (MFS) is classified as a variant of Guillain-Barré syndrome (GBS), accounting for 5%-25% of all GBS cases. Since the coronavirus disease-2019 (COVID-19) outbreak, increasing evidence has been reported of the neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, affecting both the central and peripheral nervous system. Here we report the clinical course, detailed cerebrospinal fluid (CSF) profile including CSF/blood antibody status, and neurochemical characteristics of a patient with a typical clinical presentation of MFS after a positive SARS-CoV-2 infection test.
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http://dx.doi.org/10.1111/ene.14473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7436567PMC
November 2020

Megakaryocytes use in vivo podosome-like structures working collectively to penetrate the endothelial barrier of bone marrow sinusoids.

J Thromb Haemost 2020 11 25;18(11):2987-3001. Epub 2020 Aug 25.

Université de Strasbourg, INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, Strasbourg, France.

Background: Blood platelets are anucleate cell fragments that prevent bleeding and minimize blood vessel injury. They are formed from the cytoplasm of megakaryocytes located in the bone marrow. For successful platelet production, megakaryocyte fragments must pass through the sinusoid endothelial barrier by a cell biology process unique to these giant cells as compared with erythrocytes and leukocytes. Currently, the mechanisms by which megakaryocytes interact and progress through the endothelial cells are not understood, resulting in a significant gap in our knowledge of platelet production.

Objective: The aim of this study was to investigate how megakaryocytes interact and progress through the endothelial cells of mouse bone marrow sinusoids.

Methods: We used a combination of fluorescence, electron, and three-dimensional microscopy to characterize the cellular events between megakaryocytes and endothelial cells.

Results: We identified protrusive, F-actin-based podosome-like structures, called in vivo-MK podosomes, which initiate the formation of pores through endothelial cells. These structures present a collective and spatial organization through their interconnection via a contractile network of actomyosin, essential to regulate the endothelial openings. This ensures proper passage of megakaryocyte-derived processes into the blood circulation to promote thrombopoiesis.

Conclusion: This study provides novel insight into the in vivo function of podosomes of megakaryocytes with critical importance to platelet production.
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http://dx.doi.org/10.1111/jth.15024DOI Listing
November 2020

Clinical Exome Studies Have Inconsistent Coverage.

Clin Chem 2020 01;66(1):199-206

Department of Pathology, Children's Health System of Texas, Dallas, TX.

Background: Exome sequencing has become a commonly used clinical diagnostic test. Multiple studies have examined the diagnostic utility and individual laboratory performance of exome testing; however, no previous study has surveyed and compared the data quality from multiple clinical laboratories.

Methods: We examined sequencing data from 36 clinical exome tests from 3 clinical laboratories. Exome data were compared in terms of overall characteristics and coverage of specific genes and nucleotide positions. The sets of genes examined included genes in Consensus Coding Sequence (CCDS) (n = 17723), a subset of genes clinically relevant to epilepsy (n = 108), and genes that are recommended for reporting of secondary findings (n = 57; excludes X-linked genes).

Results: The average exome nucleotide coverage (≥20×) of each laboratory varied at 96.49% (CV = 3%), 96.54% (CV = 1%), and 91.68% (CV = 4%), for laboratories A, B, and C, respectively. For CCDS genes, the average number of completely covered genes varied at 12184 (CV = 29%), 11687 (CV = 13%), and 5989 (CV = 37%), for laboratories A, B, and C, respectively. With smaller subsets of genes related to epilepsy and secondary findings, the CV revealed low consistency, with a maximum CV seen in laboratory C for both epilepsy genes (CV = 60%) and secondary findings genes (CV = 71%).

Conclusions: Poor consistency in complete gene coverage was seen in the clinical exome laboratories surveyed. The degree of consistency varied widely between the laboratories.
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http://dx.doi.org/10.1093/clinchem.2019.306795DOI Listing
January 2020

COVID-19 Neurologic Complication with CNS Vasculitis-Like Pattern.

AJNR Am J Neuroradiol 2020 08 18;41(8):1384-1387. Epub 2020 Jun 18.

Departments of Interventional Radiology (R.H.), Cardiothoracic, Vascular and Respiratory Intensive Care (P.-A.R.), Neurology and Neurophysiology (B.P.), and Neuroradiology (N.D., F.D., D.M., J.-M.C.), University Hospital of Amiens, Amiens, France.

Coronavirus disease 2019 (COVID-19) is a viral infection caused by the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), which spreads rapidly from person to person and manifests in most symptomatic patients as a respiratory illness, similar to prior SARS viruses. Neurologic manifestations of COVID-19 are uncommon; those so far reported include encephalopathy, stroke from large-vessel occlusion, and polyneuropathy. We report a unique neurologic complication of COVID-19 in a patient who had extensive cerebral small-vessel ischemic lesions resembling cerebral vasculitis in a characteristic combined imaging pattern of ischemia, hemorrhage, and punctuate postcontrast enhancement. Also, a characteristic lower extremity skin rash was present in our patient. Our observation lends support to the increasingly suspected mechanism of "endotheliitis" associated with this novel coronavirus.
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http://dx.doi.org/10.3174/ajnr.A6651DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7658880PMC
August 2020

Onboard wake vortex localization with a coherent 1.5 µm Doppler LIDAR for aircraft in formation flight configuration.

Opt Express 2020 May;28(10):14374-14385

An onboard LIght Detection And Ranging (LIDAR) sensor designed to track wake vortex created by aircraft in formation flight is presented. It uses short pulses (75 ns) to obtain a spatial resolution of ∼22.5 m required to resolve small-scale structures of vortices and a blind zone of 17.5 m to locate vortices next to the wing tip. Monte Carlo simulations show that vortex centers could be located within ±0.5 m. Flight tests were performed with two aircraft in formation flight configuration. The LIDAR, installed in the following aircraft, was able to measure, in real time (every 6 s), the air flow velocities induced by the vortices created by the leading aircraft. The software was used to determine the vortex centers. These measurements were coupled to global positioning system (GPS) measurements of the two aircraft positions to determine the falling velocity of the vortices and infer their circulations.
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http://dx.doi.org/10.1364/OE.377049DOI Listing
May 2020

Respiratory syncytial virus and human metapneumovirus after allogeneic hematopoietic stem cell transplantation: Impact of the immunodeficiency scoring index, viral load, and ribavirin treatment on the outcomes.

Transpl Infect Dis 2020 Aug 6;22(4):e13276. Epub 2020 Apr 6.

Department of Internal Medicine III, University Hospital of Ulm, Ulm, Germany.

Introduction: Respiratory viral infections are a major cause of morbidity and mortality among stem cell transplant recipients. While there is a substantial amount of information on prognostic factors and response to ribavirin therapy is available for RSV infections, this information is largely lacking for hMPV.

Patients And Methods: In total, 71 patients were included in this study: 47 patients with RSV and 24 with hMPV. Forty-one patients presented as an upper respiratory tract infection (URTI) and 30 as a primary lower respiratory tract infection (LRTI). Patients were stratified as per ISI criteria into low-, moderate-, and high-risk groups. Twenty-two patients in the URTI cohort received treatment with ribavirin (mainly oral), and 19 patients received no antiviral therapy. The decision for antiviral treatment was at the discretion of the attending physician. All 30 patients with primary LRTI and 10 patients with secondary LRTI were treated with ribavirin, 95% with the intravenous formulation. 45% of these patients received additional treatment with intravenous immunoglobulins. The viral load was assessed indirectly by using the CT value of the RT-PCR.

Results: In the cohort, as whole 11.5% suffered a virus-associated death, 5% in the URTI group, and 20% in the LRTI group. Sixty-day mortality was significantly higher in the ISI high-risk group (log-rank P = .05). Mortality was independent of the type of virus (P = .817). Respiratory failure with an indication for mechanical ventilation developed in 11.5%, this risk was independent of the type of virus. Progression from URTI to LRTI was observed in 24% of cases with a significantly higher risk (75%) in the ISI high group (log-rank P = .001). In the ISI high-risk group, treatment with ribavirin significantly reduced the risk of progression (log-rank P < .001). Neither the type of virus nor the viral load in the nasopharyngeal swab impacted the risk of progression (P = .529 and P = .141, respectively). The detection of co-pathogens in the BAL fluid was borderline significant for mortality (P = .07).

Conclusions: We could detect no differences between RSV and hMPV with respect to progression to LRTI, risk of respiratory failure or need for mechanical ventilation and virus-associated death. The ISI index is of predictive value in hMPV patients with a high ISI score and treatment with oral ribavirin has an equivalent protective effect in RSV and hMPV patients. Treatment of LRTI with intravenous ribavirin results in a similar outcome in RSV- and hMPV-infected patients. We could not detect any benefit of adjunctive treatment with immunoglobulins in both primary and secondary LRTI. No role of viral load as an independent prognostic marker could be detected either for progression to LRTI or death.
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http://dx.doi.org/10.1111/tid.13276DOI Listing
August 2020

Nuclear accumulation of MKL1 in luminal breast cancer cells impairs genomic activity of ERα and is associated with endocrine resistance.

Biochim Biophys Acta Gene Regul Mech 2020 05 27;1863(5):194507. Epub 2020 Feb 27.

Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Santé, Environnement et Travail) - UMR_S 1085, F-35000 Rennes, France. Electronic address:

Estrogen receptor (ERα) is central in driving the development of hormone-dependent breast cancers. A major challenge in treating these cancers is to understand and overcome endocrine resistance. The Megakaryoblastic Leukemia 1 (MKL1, MRTFA) protein is a master regulator of actin dynamic and cellular motile functions, whose nuclear translocation favors epithelial-mesenchymal transition. We previously demonstrated that nuclear accumulation of MKL1 in estrogen-responsive breast cancer cell lines promotes hormonal escape. In the present study, we confirm through tissue microarray analysis that nuclear immunostaining of MKL1 is associated with endocrine resistance in a cohort of breast cancers and we decipher the underlining mechanisms using cell line models. We show through gene expression microarray analysis that the nuclear accumulation of MKL1 induces dedifferentiation leading to a mixed luminal/basal phenotype and suppresses estrogen-mediated control of gene expression. Chromatin immunoprecipitation of DNA coupled to high-throughput sequencing (ChIP-Seq) shows a profound reprogramming in ERα cistrome associated with a massive loss of ERα binding sites (ERBSs) generally associated with lower ERα-binding levels. Novel ERBSs appear to be associated with EGF and RAS signaling pathways. Collectively, these results highlight a major role of MKL1 in the loss of ERα transcriptional activity observed in certain cases of endocrine resistances, thereby contributing to breast tumor cells malignancy.
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http://dx.doi.org/10.1016/j.bbagrm.2020.194507DOI Listing
May 2020

Mutation in Bmpr1b Leads to Optic Disc Coloboma and Ventral Retinal Gliosis in Mice.

Invest Ophthalmol Vis Sci 2020 02;61(2):44

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Purpose: The clinical phenotype of retinal gliosis occurs in different forms; here, we characterize one novel genetic feature, (i.e., signaling via BMP-receptor 1b).

Methods: Mouse mutants were generated within a recessive ENU mutagenesis screen; the underlying mutation was identified by linkage analysis and Sanger sequencing. The eye phenotype was characterized by fundoscopy, optical coherence tomography, optokinetic drum, electroretinography, and visual evoked potentials, by histology, immunohistology, and electron-microscopy.

Results: The mutation affects intron 10 of the Bmpr1b gene, which is causative for skipping of exon 10. The expression levels of pSMAD1/5/8 were reduced in the mutant retina. The loss of BMPR1B-mediated signaling leads to optic nerve coloboma, gliosis in the optic nerve head and ventral retina, defective optic nerve axons, and irregular retinal vessels. The ventral retinal gliosis is proliferative and hypertrophic, which is concomitant with neuronal delamination and the reduction of retinal ganglion cells (RGCs); it is dominated by activated astrocytes overexpressing PAX2 and SOX2 but not PAX6, indicating that they may retain properties of gliogenic precursor cells. The expression pattern of PAX2 in the optic nerve head and ventral retina is altered during embryonic development. These events finally result in reduced electrical transmission of the retina and optic nerve and significantly reduced visual acuity.

Conclusions: Our study demonstrates that BMPR1B is necessary for the development of the optic nerve and ventral retina. This study could also indicate a new mechanism in the formation of retinal gliosis; it opens new routes for its treatment eventually preventing scar formation in the retina.
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http://dx.doi.org/10.1167/iovs.61.2.44DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7329948PMC
February 2020

The Basal Level of Gene Expression Associated with Chromatin Loosening Shapes Waddington Landscapes and Controls Cell Differentiation.

J Mol Biol 2020 03 24;432(7):2253-2270. Epub 2020 Feb 24.

Univ Rennes, Inserm, EHESP, Irset UMR, 1085, Rennes, France. Electronic address:

The baseline level of transcription, which is variable and difficult to quantify, seriously complicates the normalization of comparative transcriptomic data, but its biological importance remains unappreciated. We show that this currently neglected ingredient is essential for controlling gene network multistability and therefore cellular differentiation. Basal expression is correlated to the degree of chromatin loosening measured by DNA accessibility and systematically leads to cellular dedifferentiation as assessed by transcriptomic signatures, irrespective of the molecular and cellular tools used. Modeling gene network motifs formally involved in developmental bifurcations reveals that the epigenetic landscapes of Waddington are restructured by the level of nonspecific expression, such that the attractors of progenitor and differentiated cells can be mutually exclusive. This mechanism is universal and holds beyond the particular nature of the genes involved, provided the multistable circuits are correctly described with autonomous basal expression. These results explain the relationships long established between gene expression noise, chromatin decondensation and cellular dedifferentiation, and highlight how heterochromatin maintenance is essential for preventing pathological cellular reprogramming, age-related diseases, and cancer.
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http://dx.doi.org/10.1016/j.jmb.2020.02.016DOI Listing
March 2020

Augmented Reality Microsurgery: A Tool for Training Micromanipulations in Ophthalmic Surgery Using Augmented Reality.

Simul Healthc 2020 Apr;15(2):122-127

From the ETH Zürich Department of Health Science and Technology (D-HEST), Zürich, Switzerland.

Introduction: Current methods of training microsurgical interventions have various limitations, including limited transferability to the human model, economic demands, and ethical concerns. In this article, we show how surgery simulations can overcome these issues and how, combined with the application of an intelligent tutoring system (ITS), they can be used to train tasks in ophthalmic surgery more efficiently.

Methods: We investigated physician trainee efficiency of learning microsurgical skills using our purpose-built microsurgery simulator that tracks a micromanipulator and displays a three-dimensional representation of the interior of a human eye in an augmented reality (AR) headset. The expertise of ophthalmic surgeons helped define five subtasks corresponding to the steps of internal limiting membrane peeling. Using our AR surgery simulation, 50 participants underwent two training sessions, one using the ITS that dynamically adapts the task sequence to the participant's progress and one using a fixed task sequence.

Results: We found significant improvement in micromanipulation performance in the first training session with both the ITS and classic training. In the second session, however, only the participants training with the ITS had further improvements in performance.

Conclusions: Results of this study demonstrate the usability of AR simulation in training micromanipulation skills and support the claim that simulators can be used in ophthalmic surgery training. This study also extends the existing literature by demonstrating an application of ITS for surgical training. The potential of this method is further analyzed in ongoing studies and discussions with experts in ophthalmic surgery.
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http://dx.doi.org/10.1097/SIH.0000000000000413DOI Listing
April 2020

Liquid chromatography-tandem mass spectrometry bioanalytical method for the determination of kavain in mice plasma: Application to a pharmacokinetic study.

J Chromatogr B Analyt Technol Biomed Life Sci 2020 Jan 13;1137:121939. Epub 2019 Dec 13.

Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil. Electronic address:

A simple and fast bioanalytical method for the quantification of kavain in mice plasma was developed using liquid chromatography (LC)-tandem mass spectrometry (MS/MS). A full method validation was performed, according to regulatory guidelines, employing isotopically labeled kavain as the internal standard (racemic-kavain-d3). For the quantification, [M+H] was formed using an electrospray ionization (ESI) source in the positive ion mode and multiple reaction monitoring (MRM) was employed using a quadrupole-linear ion trap (4000 QTRAP®) instrument. The monitored MRM transitions were 231.0 → 115.1 and 231.0 → 152.8 for kavain; and 234.2 → 199.2 for the internal standard. A linear response was obtained at the concentration range of 10 to 200 ng/mL with intra- and inter-day variations within the acceptable criteria for all quality control samples. After validation, the method was successfully applied for the quantification of kavain in mice plasma after oral administration of the kavain standard and Kava-kava extract. The plasma concentration over time results were applied for a pharmacokinetics study. The obtained pharmacokinetic parameters indicated a considerably higher bioavailability for kavain when Kava-kava extract was administered due to a pharmacokinetic synergism between the analyte and the other compounds present in the extract.
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http://dx.doi.org/10.1016/j.jchromb.2019.121939DOI Listing
January 2020

The Thrombopoietin Receptor Agonist Eltrombopag Inhibits Human Cytomegalovirus Replication Via Iron Chelation.

Cells 2019 12 20;9(1). Epub 2019 Dec 20.

Institut für Medizinische Virologie, Universitätsklinikum, Goethe-Universität, Paul Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany.

The thrombopoietin receptor agonist eltrombopag was successfully used against human cytomegalovirus (HCMV)-associated thrombocytopenia refractory to immunomodulatory and antiviral drugs. These effects were ascribed to the effects of eltrombopag on megakaryocytes. Here, we tested whether eltrombopag may also exert direct antiviral effects. Therapeutic eltrombopag concentrations inhibited HCMV replication in human fibroblasts and adult mesenchymal stem cells infected with six different virus strains and drug-resistant clinical isolates. Eltrombopag also synergistically increased the anti-HCMV activity of the mainstay drug ganciclovir. Time-of-addition experiments suggested that eltrombopag interfered with HCMV replication after virus entry. Eltrombopag was effective in thrombopoietin receptor-negative cells, and the addition of Fe prevented the anti-HCMV effects, indicating that it inhibits HCMV replication via iron chelation. This may be of particular interest for the treatment of cytopenias after hematopoietic stem cell transplantation, as HCMV reactivation is a major reason for transplantation failure. Since therapeutic eltrombopag concentrations are effective against drug-resistant viruses, and synergistically increase the effects of ganciclovir, eltrombopag is also a drug-repurposing candidate for the treatment of therapy-refractory HCMV disease.
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http://dx.doi.org/10.3390/cells9010031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7017049PMC
December 2019

The Fami-life study: protocol of a prospective observational multicenter mixed study of psychological consequences of grieving relatives in French palliative care units on behalf of the family research in palliative care (F.R.I.P.C research network).

BMC Palliat Care 2019 Dec 9;18(1):111. Epub 2019 Dec 9.

IAME, INSERM, Université de Paris, F-75018, Paris, France.

Background: Grieving relatives can suffer from numerous consequences like anxiety, depression, post-traumatic stress disorder (PTSD) symptoms, and prolonged grief. This study aims to assess the psychological consequences of grieving relatives after patients' death in French palliative care units and their needs for support.

Methods: This is a prospective observational multicenter mixed study. Relatives of adult patients with a neoplasia expected to be hospitalized more than 72 h in a palliative care unit for end-of-life issues will be included within 48 h after patient admission. End-of-life issues are defined by the physician at patient admission. Relatives who are not able to have a phone call at 6-months are excluded. The primary outcome is the incidence of prolonged grief reaction defined by an ICG (Inventory Complicate Grief) > 25 (0 best-76 worst) at 6 months after patient' death. Prespecified secondary outcomes are the risk factors of prolonged grief, anxiety and depression symptoms between day 3 and day 5 and at 6 months after patients' death based on an Hospital Anxiety and Depression score (range 0-42) > 8 for each subscale (minimal clinically important difference: 2.5), post-traumatic stress disorder symptoms 6 months after patient' death based on the Impact of Events Scale questionnaire (0 best-88 worst) score > 22, experience of relatives during palliative care based on the Fami-Life questionnaire, specifically built for the study. Between 6 and 12 months after the patient's death, a phone interview with relatives with prolonged grief reactions will be planned by a psychologist to understand the complex system of grief. It will be analyzed with the Interpretative Phenomenological Analysis. We planned to enroll 500 patients and their close relatives assuming a 25% prolonged grief rate and a 6-month follow-up available in 60% of relatives.

Discussion: This study will be the first to report the psychological consequences of French relatives after a loss of a loved one in palliative care units. Evaluating relatives' experiences can provide instrumental insights for means of improving support for relatives and evaluation of bereavement programs.

Trial Registration: NCT03748225 registered on 11/19/2018. Recruiting patients.
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http://dx.doi.org/10.1186/s12904-019-0496-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902332PMC
December 2019

[Identification of the predictive factors of new vertebral fractures in a cohort of patients who underwent a vertebroplasty for osteoporotic fracture].

Presse Med 2019 Oct 23;48(10):1175-1177. Epub 2019 Oct 23.

CHU d'Amiens, université de Picardie-Jules-Verne, service de rhumatologie, 80054 Amiens, France.

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http://dx.doi.org/10.1016/j.lpm.2019.09.033DOI Listing
October 2019

Temperature dependent N NMR study of nitric oxide.

Solid State Nucl Magn Reson 2019 09 11;101:38-43. Epub 2019 May 11.

Felix Bloch Institute for Solid State Physics, Leipzig University, Leipzig, Germany. Electronic address:

For the first time, N NMR data are obtained for a sample of nitric oxide at various temperatures. Spectra have been obtained in the liquid and solid state. In the former, the chemical shift as well as the spin-lattice relaxation time is characterized by the dynamic equilibrium of the dimerization reaction. Only the signal of the (NO) dimer is observed, while the paramagnetic NO has strong influences on the NMR parameter. From T relaxation and linewidth analysis a range for the correlation time of the exchange between monomer and dimer is obtained. SQUID measurements corroborate the NMR analysis.
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http://dx.doi.org/10.1016/j.ssnmr.2019.05.002DOI Listing
September 2019

Fast breakthrough of resistant cytomegalovirus during secondary letermovir prophylaxis in a hematopoietic stem cell transplant recipient.

BMC Infect Dis 2019 May 8;19(1):388. Epub 2019 May 8.

Institut für Virologie, Universitätsklinikum Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany.

Background: The compound letermovir (LMV) has recently been approved for the prophylaxis of cytomegalovirus (CMV) infection and disease in adult CMV seropositive recipients of an allogeneic hematopoietic stem cell transplant. LMV inhibits CMV replication by binding to the viral terminase complex. However, first cases of clinical LMV resistance have been occurred. Here we report a fast breakthrough of resistant cytomegalovirus during secondary LMV prophylaxis in a hematopoietic-cell transplant recipient.

Case Presentation: A 44-year-old male patient with acute myeloid leukemia (AML) experienced a CMV-reactivation within the first 4 weeks of allogeneic hematopoietic-cell transplantation. Administration of LMV was initiated at day + 34. Due to increasing viral loads, LMV treatment was discontinued after 8 days. The patient was then administered with valganciclovir (valGCV) until viral DNA was undetectable. Due to neutropenia, valGCV treatment was switched to LMV secondary prophylaxis. For 4 weeks, the patient maintain virologic suppression. Then, CMV viral loads increased with a fast kinetic. Genotypic testing of the viral polymerase UL54, the kinase UL97 as well as the viral terminase UL56 and UL89 revealed the mutation C325Y in UL56, which is associated with the high level LMV resistance.

Conclusion: It is known that Letermovir is approved for prophylactic purposes. However, it may be used for some patients with CMV infection who either have failed prior therapies or are unable to tolerate other anti-CMV compounds. Particularly, the administration of LMV should be avoided in patients with detectable viral loads. When this is not possible, viral load must be routinely monitored along with UL56 genotyping. Furthermore, LMV administration at high virus loads may foster the rapid selection of resistant CMV mutants.
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http://dx.doi.org/10.1186/s12879-019-4016-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6505103PMC
May 2019

Tripled yield in direct-drive laser fusion through statistical modelling.

Nature 2019 01 30;565(7741):581-586. Epub 2019 Jan 30.

Massachusetts Institute of Technology, Cambridge, MA, USA.

Focusing laser light onto a very small target can produce the conditions for laboratory-scale nuclear fusion of hydrogen isotopes. The lack of accurate predictive models, which are essential for the design of high-performance laser-fusion experiments, is a major obstacle to achieving thermonuclear ignition. Here we report a statistical approach that was used to design and quantitatively predict the results of implosions of solid deuterium-tritium targets carried out with the 30-kilojoule OMEGA laser system, leading to tripling of the fusion yield to its highest value so far for direct-drive laser fusion. When scaled to the laser energies of the National Ignition Facility (1.9 megajoules), these targets are predicted to produce a fusion energy output of about 500 kilojoules-several times larger than the fusion yields currently achieved at that facility. This approach could guide the exploration of the vast parameter space of thermonuclear ignition conditions and enhance our understanding of laser-fusion physics.
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http://dx.doi.org/10.1038/s41586-019-0877-0DOI Listing
January 2019

In Vivo Emergence of UL56 C325Y Cytomegalovirus Resistance to Letermovir in a Patient with Acute Myeloid Leukemia after Hematopoietic Cell Transplantation.

Mediterr J Hematol Infect Dis 2019 1;11(1):e2019001. Epub 2019 Jan 1.

Klinik für Innere Medizin II, Hämatologie und internistische Onkologie, Universitätsklinikum Jena, Jena, Germany.

CMV associated tissue-invasive disease is associated with a considerable risk of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Recently, the terminase inhibitor letermovir (LMV) has been approved for prophylaxis of CMV infection in HSCT. We hereby report a 60-year-old female experiencing CMV reactivation after HSCT in a CMV seronegative donor-constellation. Due to ongoing elevated CMV viral load and drug-associated myelosuppression, which prevented ganciclovir therapy, treatment was replaced by foscarnet. Due to nephrotoxicity, foscarnet was switched to LMV. The patient developed skin GvHD and prednisolone was started. Subsequently, CMV viremia worsened despite LMV therapy. Genotyping revealed the mutation C325Y of the CMV UL56 terminase being associated with high-level resistance against LMV. Prolonged uncontrolled low-level viremia due to prednisolone treatment may have favored the selection of drug-resistant CMV. Despite the excellent toxicity profile of LMV, physicians should be aware of risk factors for the emergence of resistance.
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http://dx.doi.org/10.4084/MJHID.2019.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6328044PMC
January 2019

A Zr-labeled lipoplex nanosystem for image-guided gene delivery: design, evaluation of stability and in vivo behavior.

Int J Nanomedicine 2018 21;13:7801-7818. Epub 2018 Nov 21.

Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada,

Background: With the advances in radiopharmaceutical research, the development of image-guided therapy has become a major interest. While the development of theranostic nanotherapeutics is frequently associated with cancer chemotherapy, phototherapy and radiotherapy, there is little information available on the in vivo monitoring of gene delivery systems and the application of image-guided approach in gene therapy. The goal of this work was to determine the in vivo behavior of DNA delivery nanosystems - based on cationic gemini surfactants - designed for image-guided gene therapy. We tested the feasibility of monitoring tumor accumulation of gene delivery nanoparticles by positron emission tomography.

Methods: To be able to conjugate radiotracers to the nanoparticles, a deferoxamine-modified gemini surfactant was synthesized, DNA-containing lipoplex nanoparticles were formulated, and radiolabeled with Zirconium-89 (Zr). The pharmacokinetics and biodistribution of Zr labeled surfactant and Zr labeled nanoparticles were monitored in mice by microPET/CT imaging and ex vivo gamma counting.

Results: Modification of the nanoparticles with deferoxamine did not alter their physicochemical properties. The radiolabeled nanoparticles (labeling efficiency of 95±3%) were stable in PBS and serum. The biological half-life of the Zr labeled nanoparticles was significantly higher compared to Zr labeled surfactant. As expected, the nanoparticles had significantly higher liver accumulation than the radiolabeled surfactant alone and lower kidney accumulation. Tumor uptake was detected at 2 hours post injection and decreased throughout the 3-day monitoring.

Conclusion: We propose that radiolabeling DNA delivery lipoplex nanosystems is a promising approach for the design and optimization of image-guided nanomedicines, especially in the context of cancer gene therapy.
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http://dx.doi.org/10.2147/IJN.S179806DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6257135PMC
January 2019

Effectiveness of antibacterial prophylaxis in children with acute leukemia: A report from a single institution over a 20-year period.

Arch Pediatr 2018 Nov 16;25(8):464-468. Epub 2018 Oct 16.

Pediatric oncology department, Nancy university hospital, 54511 Vandoeuvre, France.

Background: Infection is the major cause of treatment-related mortality in childhood acute leukemia, mainly due to bacterial translocation across the intestinal mucosa. Only a few studies have reported the impact of different antibacterial prophylaxis treatments on digestive tract flora and infection-related mortality.

Procedures: We performed a retrospective analysis of two different digestive tract decontamination modalities (selective or total digestive decontamination) in a large single-center series of 323 children during the induction treatment of acute leukemia between January 1995 and December 2014. We examined the impact of antibiotic prophylaxis and food regimen (sterile or selected) on the digestive tract flora during the period of antibacterial prophylaxis, on the frequency of bacteremia, and on antibiotic sensitivity.

Results: Only one Gram-negative (Klebsiella pneumonia) translocation occurred in the SDD group. No infection-related death occurred. Extended-spectrum beta-lactamase (ESBL) bacteria were observed in seven of 170 (4%) patients in the SDD group. The faecal-flora total suppression and faecal-flora Gram-negative bacilli suppression was 67 and 77%, respectively, in the TDD group with sterile food, 0 and 58%, respectively, in the SDD group with sterile food, and 6 and 63%, respectively, in the SDD group with selective food.

Conclusions: This study gives a rationale not to use antibacterial prophylaxis systematically in children who receive induction treatment for acute leukemia; additionally, antibiotics should only be used in case of stool contamination by highly pathogenic bacteria with a high potential of translocation.
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http://dx.doi.org/10.1016/j.arcped.2018.09.012DOI Listing
November 2018

Validation of a simplified in vitro Transwell model of the alveolar surface to assess host immunity induced by different morphotypes of Aspergillus fumigatus.

Int J Med Microbiol 2018 Dec 3;308(8):1009-1017. Epub 2018 Sep 3.

Medical Hospital II, University Hospital Wuerzburg, 97080 Wuerzburg, Germany. Electronic address:

Interactions between fungal pathogens such as Aspergillus fumigatus with host alveolar epithelium and innate immune cells are crucial in the defense against opportunistic fungal infections. In this study a simplified Transwell system with a confluent layer of A549 cells acted as a model for the alveolar surface. A. fumigatus and dendritic cells were added to simulate the spatial and cellular complexity in the alveolus. Fungal growth into the lower chamber was validated by galactomannan assays. Addition of moDCs to the upper chamber led to a reduced GM signal and fungal growth, indicating moDC antifungal activity. Minimal cell death was documented by analyses of lactate dehydrogenase concentrations and pro-apoptotic gene expression. Measurement of trans-epithelial dextran blue movement confirmed tightness of the epithelial barrier even in presence of A. fumigatus. Cytokine measurements in supernatants from both chambers of the Transwell system documented distinct response patterns during early and late stages of epithelial invasion, with A549 cells appearing to make a minimal contribution to cytokine release. Concentrations of cytokines in the lower chamber varied distinctly from the upper chamber, depending on the molecular weight of the cytokines. Low inter-assay variability of fungal biomarkers and cytokines was confirmed, highlighting that in vitro models closely mimicking conditions in the human lung can facilitate reproducible measurement of the dynamics of cytokine release and fungal penetration of host epithelia.
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http://dx.doi.org/10.1016/j.ijmm.2018.09.001DOI Listing
December 2018

Molecular Engineering as an Approach To Modulate Gene Delivery Efficiency of Peptide-Modified Gemini Surfactants.

Bioconjug Chem 2018 10 13;29(10):3293-3308. Epub 2018 Sep 13.

Canadian Light Source , Saskatoon , Saskatchewan S7N 4L5 , Canada.

The unique molecular structure confers the diquaternary ammonium gemini surfactants with enhanced nucleic acid complexation ability, bottom-up design flexibility, and relatively low cytotoxicity. To capitalize on their potential as gene delivery vectors, novel structural modifications should be explored. In this work, 22 novel peptide-modified gemini surfactants with various alkyl tails and peptide spacer modifications were evaluated. This work represents the first report of dendrimer-like gemini surfactants and first evaluation of the impact of incorporating a hydrocarbon linker into the peptide chain. Our aim was to establish a structure activity relationship of the peptide-modified gemini surfactants and to identify the fundamental architectural requirements needed for the ultimate gene delivery systems. In vitro assessment revealed that the highest transfection efficiency and lowest cytotoxicity were associated with the glycyl-lysine modified gemini surfactants having the hexadecyl tail, 16-7N(G-K)-16. In fact, it showed an 8-fold increase in secreted protein with 20% increase in cell viability relative to the first-generation unsubstituted gemini surfactants. Further increase in the size of the attached peptides resulted in a decrease in the transfection efficiency and cell viability. Whereas the incorporation of a hydrocarbon linker into the peptide chain decreased the transfection efficiency of compounds with dipeptides, it increased the transfection efficiency of compounds with larger peptide chains. Such an increase was more prominent with the incorporation of a longer hydrocarbon linker. We conclude that a balance between the hydrophilic and hydrophobic characteristics of the compound is necessary since it results in physicochemical parameters conducive to the gene delivery process.
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http://dx.doi.org/10.1021/acs.bioconjchem.8b00480DOI Listing
October 2018

The development of simple flow injection analysis tandem mass spectrometric methods for the cutaneous determination of peptide-modified cationic gemini surfactants used as gene delivery vectors.

J Pharm Biomed Anal 2018 Sep 2;159:536-547. Epub 2018 Jul 2.

College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada. Electronic address:

Diquaternary ammonium gemini surfactants are a class of non-viral gene delivery vectors, primarily studied for their dermal applications. However, their biological fate has rarely been investigated. In this work, we developed simple flow injection analysis tandem mass spectrometric methods, (FIA)-MS/MS, to understand the fate and biodistribution of topically applied gemini surfactant-based therapeutics in an ex-vivo skin model. Three peptide-modified gemini surfactants with varied structures and transfection efficiencies were evaluated. For each compound, two methods were developed to quantify their presence in skin tissue and in phosphate buffered saline (PBS). The methods were developed using single-point calibration mode. Skin penetration was assessed on CD1 mice dorsal skin tissue mounted in a Franz diffusion cell after extraction. Amongst the five evaluated liquid-liquid extraction protocols, the Folch method provides the highest extraction efficiency for all compounds. Weak cationic exchange solid phase extraction was also used to further isolate gemini surfactants from endogenous skin lipids. FIA-MS/MS analysis of the skin revealed that all compounds were detected in the skin with minimal partition into the PBS compartment, which represents circulation. Interestingly, the detected amounts of gemini lipids in the skin were correlated with their transfection efficiencies.
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http://dx.doi.org/10.1016/j.jpba.2018.06.063DOI Listing
September 2018

Subpercent-Scale Control of 3D Low Modes of Targets Imploded in Direct-Drive Configuration on OMEGA.

Phys Rev Lett 2018 Mar;120(12):125001

Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636, USA.

Multiple self-emission x-ray images are used to measure tomographically target modes 1, 2, and 3 up to the end of the target acceleration in direct-drive implosions on OMEGA. Results show that the modes consist of two components: the first varies linearly with the laser beam-energy balance and the second is static and results from physical effects including beam mistiming, mispointing, and uncertainty in beam energies. This is used to reduce the target low modes of low-adiabat implosions from 2.2% to 0.8% by adjusting the beam-energy balance to compensate these static modes.
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http://dx.doi.org/10.1103/PhysRevLett.120.125001DOI Listing
March 2018

Synthesis of Galactosylated Glycosylphosphatidylinositol Derivatives from Trypanosoma brucei.

Chemistry 2018 Mar 1;24(13):3271-3282. Epub 2018 Feb 1.

Biomolecular Systems Department, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany.

Trypanosoma brucei uses variant surface glycoproteins (VSGs) to evade the host immune system and ensure parasitic longevity in animals and humans. VSGs are attached to the cell membrane by complex glycosylphosphatidylinositol anchors (GPI). Distinguishing structural feature of VSG GPIs are multiple α- and β-galactosides attached to the conserved GPI core structure. T. brucei GPIs have been associated with macrophage activation and alleviation of parasitemia during infection, acting as disease onset delaying antigens. Literature reports that link structural modifications in the GPIs to changes in biological activity are contradictory. We have established a synthetic route to prepare structurally overlapping GPI derivatives bearing different T. brucei characteristic structural modifications. The GPI collection will be used to assess the effect of galactosylation and phosphorylation on T. brucei GPI immunomodulatory activity, and to perform an epitope mapping of this complex glycolipid as potential diagnostic marker for Trypanosomiasis. A strategy for the synthesis of a complete α-tetragalactoside using the 2-naphthylmethyl protecting group and for subsequent attachment of GPI fragments to peptides is presented.
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http://dx.doi.org/10.1002/chem.201705511DOI Listing
March 2018