374 research outputs found

    BLINDED VS ULTRASOUND-GUIDED CORTICOSTEROID INJECTIONS for the TREATMENT of the GREATER TROCHANTERIC PAIN SYNDROME (SDPT): A RANDOMIZED CONTROLLED TRIAL

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    Universidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilWeb of Scienc

    Integral representation of the RPA correlation energy

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    Using the spectral function F'(z)/F(z) the RPA correlation energy and other properties of a finite system can be written as a contour integral in a compact way. This yields a transparent expression and reduces drastically the numerical efforts for obtaining reliable values. The method applied to pairing vibrations in rotating nuclei as an illustrative example.Comment: 9 pages, 2 figures (eps files

    Identification and functional characterization of a highly divergent N-acetylglucosaminyltransferase I (TbGnTI) in <em>Trypanosoma brucei</em>

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    Trypanosoma brucei expresses a diverse repertoire of N-glycans, ranging from oligomannose and paucimannose structures to exceptionally large complex N-glycans. Despite the presence of the latter, no obvious homologues of known β1–4-galactosyltransferase or β1–2- or β1–6-N-acetylglucosaminyltransferase genes have been found in the parasite genome. However, we previously reported a family of putative UDP-sugar-dependent glycosyltransferases with similarity to the mammalian β1–3-glycosyltransferase family. Here we characterize one of these genes, TbGT11, and show that it encodes a Golgi apparatus resident UDP-GlcNAc:α3-d-mannoside β1–2-N-acetylglucosaminyltransferase I activity (TbGnTI). The bloodstream-form TbGT11 null mutant exhibited significantly modified protein N-glycans but normal growth in vitro and infectivity to rodents. In contrast to multicellular organisms, where the GnTI reaction is essential for biosynthesis of both complex and hybrid N-glycans, T. brucei TbGT11 null mutants expressed atypical “pseudohybrid” glycans, indicating that TbGnTII activity is not dependent on prior TbGnTI action. Using a functional in vitro assay, we showed that TbGnTI transfers UDP-GlcNAc to biantennary Man(3)GlcNAc(2), but not to triantennary Man(5)GlcNAc(2), which is the preferred substrate for metazoan GnTIs. Sequence alignment reveals that the T. brucei enzyme is far removed from the metazoan GnTI family and suggests that the parasite has adapted the β3-glycosyltransferase family to catalyze β1–2 linkages

    H3N2 influenza A virus gradually adapts to human-type receptor binding and entry specificity after the start of the 1968 pandemic

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    To become established upon zoonotic transfer, influenza A viruses (IAV) need to switch binding from "avian-type" α2-3-linked sialic acid receptors (2-3Sia) to "human-type" Siaα2-6-linked sialic acid receptors (2-6Sia). For the 1968 H3N2 pandemic virus, this was accomplished by two canonical amino acid substitutions in its hemagglutinin (HA) although a full specificity shift had not occurred. The receptor repertoire on epithelial cells is highly diverse and simultaneous interaction of a virus particle with a range of low- to very low-affinity receptors results in tight heteromultivalent binding. How this range of affinities determines binding selectivity and virus motility remains largely unknown as the analysis of low-affinity monovalent HA-receptor interactions is technically challenging. Here, a biolayer interferometry assay enabled a comprehensive analysis of receptor-binding kinetics evolution upon host-switching. Virus-binding kinetics of H3N2 virus isolates slowly evolved from 1968 to 1979 from mixed 2-3/2-6Sia specificity to high 2-6Sia specificity, surprisingly followed by a decline in selectivity after 1992. By using genetically tuned HEK293 cells, presenting either a simplified 2-3Sia- or 2-6Sia-specific receptor repertoire, receptor-specific binding was shown to correlate strongly with receptor-specific entry. In conclusion, the slow and continuous evolution of entry and receptor-binding specificity of seasonal H3N2 viruses contrasts with the paradigm that human IAVs need to rapidly acquire and maintain a high specificity for 2-6Sia. Analysis of the kinetic parameters of receptor binding provides a basis for understanding virus-binding specificity, motility, and HA/neuraminidase balance at the molecular level

    Atomic and Specificity Details of Mucin 1 O-Glycosylation Process by Multiple Polypeptide GalNAc-Transferase Isoforms Unveiled by NMR and Molecular Modeling

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    IF/00780/2015 PTDC/BIA-MIB/31028/2017 UIDP/04378/2020 UIDB/04378/2020 LA/P/0140/2020 SFRH/BD/140394/2018 PD/BD/142847/2018 PD00065/2013 DL 57/2016 ROTEIRO/0031/2013-PINFRA/22161/2016 BFU2016-75633-P PID2019-105451GB-I00 E34_R17 LMP58_18 to R.H-G RTI2018-099592-B-C21 ITN, GA-642157 COST Action GLYCONanoProbes (CA18132) ERC-2017-AdG, project number 788143-RECGLYCANMR RTI218-094751-B-C21) DNRF107The large family of polypeptide GalNAc-transferases (GalNAc-Ts) controls with precision how GalNAc O-glycans are added in the tandem repeat regions of mucins (e.g., MUC1). However, the structural features behind the creation of well-defined and clustered patterns of O-glycans in mucins are poorly understood. In this context, herein, we disclose the full process of MUC1 O-glycosylation by GalNAc-T2/T3/T4 isoforms by NMR spectroscopy assisted by molecular modeling protocols. By using MUC1, with four tandem repeat domains as a substrate, we confirmed the glycosylation preferences of different GalNAc-Ts isoforms and highlighted the importance of the lectin domain in the glycosylation site selection after the addition of the first GalNAc residue. In a glycosylated substrate, with yet multiple acceptor sites, the lectin domain contributes to orientate acceptor sites to the catalytic domain. Our experiments suggest that during this process, neighboring tandem repeats are critical for further glycosylation of acceptor sites by GalNAc-T2/T4 in a lectin-assisted manner. Our studies also show local conformational changes in the peptide backbone during incorporation of GalNAc residues, which might explain GalNAc-T2/T3/T4 fine specificities toward the MUC1 substrate. Interestingly, we postulate that a specific salt-bridge and the inverse γ-turn conformation of the PDTRP sequence in MUC1 are the main structural motifs behind the GalNAc-T4 specificity toward this region. In addition, in-cell analysis shows that the GalNAc-T4 isoform is the only isoform glycosylating the Thr of the immunogenic epitope PDTRP in vivo, which highlights the relevance of GalNAc-T4 in the glycosylation of this epitope. Finally, the NMR methodology established herein can be extended to other glycosyltransferases, such as C1GalT1 and ST6GalNAc-I, to determine the specificity toward complex mucin acceptor substrates.publishersversionepub_ahead_of_prin

    Genetics of human neural tube defects

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    Neural tube defects (NTDs) are common, severe congenital malformations whose causation involves multiple genes and environmental factors. Although more than 200 genes are known to cause NTDs in mice, there has been rather limited progress in delineating the molecular basis underlying most human NTDs. Numerous genetic studies have been carried out to investigate candidate genes in cohorts of patients, with particular reference to those that participate in folate one-carbon metabolism. Although the homocysteine remethylation gene MTHFR has emerged as a risk factor in some human populations, few other consistent findings have resulted from this approach. Similarly, attention focused on the human homologues of mouse NTD genes has contributed only limited positive findings to date, although an emerging association between genes of the non-canonical Wnt (planar cell polarity) pathway and NTDs provides candidates for future studies. Priorities for the next phase of this research include: (i) larger studies that are sufficiently powered to detect significant associations with relatively minor risk factors; (ii) analysis of multiple candidate genes in groups of well-genotyped individuals to detect possible gene–gene interactions; (iii) use of high throughput genomic technology to evaluate the role of copy number variants and to detect ‘private’ and regulatory mutations, neither of which have been studied to date; (iv) detailed analysis of patient samples stratified by phenotype to enable, for example, hypothesis-driven testing of candidates genes in groups of NTDs with specific defects of folate metabolism, or in groups of fetuses with well-defined phenotypes such as craniorachischisis

    New findings on the fungal species Tricholoma matsutake from Ukraine, and revision of its taxonomy and biogeography based on multilocus phylogenetic analyses

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    Publisher Copyright: © 2022 Elsevier B.V.. All rights reserved.Matsutake mushrooms are among the best-known edible wild mushroom taxa worldwide. The representative Tricholoma matsutake is from East Asia and the northern and central regions of Europe. Here, we report the existence of T. matsutake under fir trees in Eastern Europe (i.e., Ukraine), as confirmed by phylogenetic analysis of nine loci on the nuclear and mitochondrial genomes. All specimens from Japan, Bhutan, China, North Korea, South Korea, Sweden, Finland, and Ukraine formed a T. matsutake clade according to the phylogeny of the internal transcribed spacer region. The European population of T. matsutake was clustered based on the β2 tubulin gene, with a moderate bootstrap value. In contrast, based on analyses of three loci, i.e., rpb2, tef1, and the β2 tubulin gene, T. matsutake specimens sampled from Bhutan and China belonged to a clade independent of the other specimens of this species, implying a genetically isolated population. As biologically available type specimens of T. matsutake have not been designated since its description as a new species from Japan in 1925, we established an epitype of this fungus, sampled in a Pinus densiflora forest in Nagano, Japan.Peer reviewe

    Asian-variant intravascular lymphoma in the African race

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    Intravascular Large B-cell lymphoma (IVLBCL) is an exceptionally rare form of non-Hodgkin lymphoma (NHL) distinguished by the preferential growth of neoplastic cells within blood vessel lumen. Challenging to detect and deemed disseminated at diagnosis, this condition is characterized by a highly aggressive, inconspicuous course with a high mortality rate. We describe the case of a 48 year-old African-American female presenting with a two month history of low-grade fevers and malaise. Laboratory data was notable for anemia, thrombocytopenia, elevated liver function tests, and hematuria. An extensive work-up for infectious, rheumatologic and malignant causes was negative. Her symptoms progressed and within two weeks, she was admitted for disseminated intravascular coagulation (DIC). Her course was complicated by diffuse pulmonary hemorrhage and ultimately, care was withdrawn. Autopsy identified widespread CD-20 positive intravascular large B-cell lymphoma with significant hepatosplenic involvement, characteristic of the Asian variant IVLBCL. This case uniquely highlights development of the Asian variant IVLBVL in a previously undescribed race. Identified by its intraluminal vascular growth pattern, IVLBCL generally spares lymphatic channels. Diagnosis and differentiation of this condition from other hematological malignancies via skin, visceral and bone marrow biopsy is imperative as anthracycline-containing chemotherapies may significantly improve clinical outcomes. This article outlines the common presentation, natural course, and treatment options of IVLBCL, along with the histopathology, immunohistochemistry, and chromosomal aberrations common to this condition

    Long-term complications and side effects after allogeneic hematopoietic stem cell transplantation: an update

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    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapy for various malignant and non-malignant diseases. Many patients have now been followed for two or three decades posttransplant and are presumed to be cured. With the tremendous advances achieved in terms of supportive care, it is reasonable to expect outcomes to improve steadily and consequently increasing numbers of transplant survivors will be facing life after the initial transplant experience. Although long-term allo-HSCT survivors generally enjoy good health, for many others, cure or control of the underlying disease is not accompanied by full restoration of health. The burden of long-term morbidity borne by allo-HSCT survivors is substantial, and long-term follow-up of patients who received allo-HSCT is now widely recommended. Immediate survival is no longer the sole concern after allo-HSCT. The goals should also include complete recovery of the overall health status with normal physical and psychological functioning. Long-term side effects after allo-HSCT include non-malignant organ or tissue dysfunction, changes in quality of life, infections related to abnormal immune reconstitution and secondary cancers. Many of these can be attributed to the deleterious effects of chronic graft-versus-host disease. The aims of this review are to provide an update on the recent research evidence in the field
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