A 92-year-old Japanese woman presented with a mass in the left breast, and sparganosis was suspected by biopsy of the mass. The mass disappeared once, but it reappeared at the same site one year later. For a definitive diagnosis, the mass was surgically removed, and a sparganum-like worm was detected.
View Article and Find Full Text PDFBackground: EOS plays an important role in maintaining the suppressive function of regulatory T cells (Tregs), and induces a regulated transformation of Tregs into T helper-like cells, which are capable of secreting proinflammatory cytokines in response to specific inflammatory signals. Meanwhile, significant reduction in Treg activity along with production of proinflammatory cytokines has been reported in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP).
Methods: In this study, to examine whether there is an alteration in EOS expression in peripheral blood mononuclear cells (PBMCs) derived from HTLV-1-infected individuals especially HAM/TSP, we investigated the expression of HTLV-1 tax genotype, proviral load (PVL), and the mRNA expression of tax, HBZ and EOS in HTLV-1 infected individuals including adult T-cell leukemia/lymphoma (ATL), HAM/TSP, or asymptomatic carriers.
In various positive-sense single-stranded RNA viruses, a low-fidelity viral RNA-dependent RNA polymerase (RdRp) confers attenuated phenotypes by increasing the mutation frequency. We report a negative-sense single-stranded RNA virus RdRp mutant strain with a mutator phenotype. Based on structural data of RdRp, rational targeting of key residues, and screening of fidelity variants, we isolated a novel low-fidelity mutator strain of influenza virus that harbors a Tyr82-to-Cys (Y82C) single-amino-acid substitution in the PB1 polymerase subunit.
View Article and Find Full Text PDFBackground: Among human T cell leukemia virus type 1 (HTLV-1)-infected individuals, there is an association between HTLV-1 tax subgroups (subgroup-A or subgroup-B) and the risk of HAM/TSP in the Japanese population. To investigate the role of HTLV-1 subgroups in viral pathogenesis, we studied the functional difference in the subgroup-specific viral transcriptional regulators Tax and HBZ using microarray analysis, reporter gene assays, and evaluation of viral-host protein-protein interaction.
Results: (1) Transcriptional changes in Jurkat Tet-On human T-cells that express each subgroup of Tax or HBZ protein under the control of an inducible promoter revealed different target gene profiles; (2) the number of differentially regulated genes induced by HBZ was 2-3 times higher than that induced by Tax; (3) Tax and HBZ induced the expression of different classes of non-coding RNAs (ncRNAs); (4) the chemokine CXCL10, which has been proposed as a prognostic biomarker for HAM/TSP, was more efficiently induced by subgroup-A Tax (Tax-A) than subgroup-B Tax (Tax-B), in vitro as well as in unmanipulated (ex vivo) PBMCs obtained from HAM/TSP patients; (5) reporter gene assays indicated that although transient Tax expression in an HTLV-1-negative human T-cell line activated the CXCL10 gene promoter through the NF-κB pathway, there was no difference in the ability of each subgroup of Tax to activate the CXCL10 promoter; however, (6) chromatin immunoprecipitation assays showed that the ternary complex containing Tax-A is more efficiently recruited onto the promoter region of CXCL10, which contains two NF-κB binding sites, than that containing Tax-B.
Background: Chemokine (C-C motif) ligand 1 (CCL1) is produced by activated monocytes/ macrophages and T-lymphocytes, and acts as a potent attractant for Th2 cells and a subset of T-regulatory (Treg) cells. Previous reports have indicated that CCL1 is overexpressed in adult T-cell leukemia cells, mediating an autocrine anti-apoptotic loop. Because CCL1 is also known as a potent chemoattractant that plays a major role in inflammatory processes, we investigated the role of CCL1 in the pathogenesis of human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP).
View Article and Find Full Text PDFVaccination is considered the most effective preventive means for influenza control. The development of a master virus with high growth and genetic stability, which may be used for the preparation of vaccine viruses by gene reassortment, is crucial for the enhancement of vaccine performance and efficiency of production. Here, we describe the generation of a high-fidelity and high-growth influenza vaccine master virus strain with a single V43I amino acid change in the PB1 polymerase of the high-growth A/Puerto Rico/8/1934 (PR8) master virus.
View Article and Find Full Text PDFMethods to maintain the life cycle of pathogenic organisms become powerful tools for studying molecular and cellular bases of infectious diseases. Spirometra erinaceieuropaei is a parasitic tapeworm that causes sparganosis in humans. Because S.
View Article and Find Full Text PDFBackground: Seasonally prevalent H1N1 and H3N2 influenza A viruses have evolved by antigenic drift; this evolution has resulted in the acquisition of asparagine (N)-linked glycosylation sites (NGSs) in the globular head of hemagglutinin (HA), thereby affecting the antigenic and receptor-binding properties, as well as virulence. An epidemiological survey indicated that although the traditional seasonal H1N1 strain had disappeared, H3N2 became predominant again in the seasons (2010-11 and 2011-12) immediately following the H1N1 pandemic of 2009. Interestingly, although the 2009 pandemic H1N1 strain (H1N1pdm09) lacks additional NGSs, clinically isolated H3N2 strains obtained during these seasons gained N (Asn) residues at positions 45 and 144 of HA that forms additional NGSs.
View Article and Find Full Text PDFBackground: Neuraminidase (NA) inhibitors used for influenza therapy are believed to prevent the release of progeny virus from the surface of an infected cell. In this study, we found that NA inhibitors have a novel antiviral function against an avian influenza virus.
Results: Madin-Darby canine kidney cells, commonly used for the isolation and propagation of the influenza virus, were infected with an avian influenza viral strain A/chicken/German/N/49(H10N7) (H10/chicken) or a human influenza viral strain A/Osaka/981/98(H3N2) (H3/Osaka) virus.
Background: Mannose-binding lectin (MBL) is an important component of innate immunity because it promotes bacterial clearance and neutralization of human influenza A viruses. Since a majority of humans have no neutralizing antibody against the pandemic (H1N1) 2009 influenza (pandemic 2009) virus, innate immunity may be crucial and MBL susceptibility may therefore influence viral pathogenesis.
Results: We examined MBL susceptibility of influenza A viruses and observed that the pandemic 2009 virus was resistant to MBL, whereas all seasonal influenza A viruses tested were susceptible.
The waveform and the free-running period of circadian rhythms in constant conditions are often modulated by preceding lighting conditions. We have examined the modulatory effect of variable length of light phase of a 24h light cycle on the ratio of activity (alpha) and rest phase (rho) as well as on the free-running period of the locomotor rhythm in the cricket Gryllus bimaculatus. When experienced the longer light phases, the alpha/rho-ratio was smaller and the free-running period was shorter.
View Article and Find Full Text PDFThe morphology of metacercariae of Massaliatrema misgurni Ohyama et al. (Ohyama et al., Parasitol Int 2001; 50; 267-71) was described, and their infectivity, egg output, growth and development in mice until day 35 post infection (PI) were studied.
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