178 research outputs found

    Identification of Multiple Domains of Entamoeba histolytica Intermediate Subunit Lectin-1 with Hemolytic and Cytotoxic Activities

    Get PDF
    Galactose and N-acetyl-D-galactosamine-inhibitable lectin of Entamoeba histolytica have roles in the pathogenicity of intestinal amoebiasis. Igl1, the intermediate subunit lectin-1 of E. histolytica, has been shown to have both hemolytic and cytotoxic activities that reside in the C-terminus of the protein. To identify the amino acid regions responsible for these activities, recombinant proteins were prepared and used in hemolytic and cytotoxic assays. The results revealed that Igl1 has multiple domains with hemolytic and cytotoxic activities and that amino acids 787-846, 968-1028 and 1029-1088 are involved in these activities. The hemolytic activities of the fragments were partly inhibited by mannose, galactose and N-acetylgalactosamine, and glucose showed lower or negligible inhibitory effects for the activities. This is the first report of a protozoan protein with hemolytic and cytotoxic activities in multiple domains

    Cross-Speaker Emotion Transfer for Low-Resource Text-to-Speech Using Non-Parallel Voice Conversion with Pitch-Shift Data Augmentation

    Full text link
    Data augmentation via voice conversion (VC) has been successfully applied to low-resource expressive text-to-speech (TTS) when only neutral data for the target speaker are available. Although the quality of VC is crucial for this approach, it is challenging to learn a stable VC model because the amount of data is limited in low-resource scenarios, and highly expressive speech has large acoustic variety. To address this issue, we propose a novel data augmentation method that combines pitch-shifting and VC techniques. Because pitch-shift data augmentation enables the coverage of a variety of pitch dynamics, it greatly stabilizes training for both VC and TTS models, even when only 1,000 utterances of the target speaker's neutral data are available. Subjective test results showed that a FastSpeech 2-based emotional TTS system with the proposed method improved naturalness and emotional similarity compared with conventional methods.Comment: Submitted to Interspeech 202

    Novel hemagglutinating, hemolytic and cytotoxic activities of the intermediate subunit of Entamoeba histolytica lectin

    Get PDF
    Galactose and N-acetyl-D-galactosamine (Gal/GalNAc) inhibitable lectin of Entamoeba histolytica, a common protozoan parasite, has roles in pathogenicity and induction of protective immunity in mouse models of amoebiasis. The lectin consists of heavy (Hgl), light (Lgl), and intermediate (Igl) subunits. Hgl has lectin activity and Lgl does not, but little is known about the activity of Igl. In this study, we assessed various regions of Igl for hemagglutinating activity using recombinant proteins expressed in Escherichia coli. We identified a weak hemagglutinating activity of the protein. Furthermore, we found novel hemolytic and cytotoxic activities of the lectin, which resided in the carboxy-terminal region of the protein. Antibodies against Igl inhibited the hemolytic activity of Entamoeba histolytica trophozoites. This is the first report showing hemagglutinating, hemolytic and cytotoxic activities of an amoebic molecule, Igl

    Cessation of gastrulation is mediated by suppression of epithelial-mesenchymal transition at the ventral ectodermal ridge

    Get PDF
    In the gastrula stage embryo, the epiblast migrates toward the primitive streak and ingresses through the primitive groove.Subsequently, the ingressing epiblast cells undergo epithelial-mesenchymal transition (EMT) and differentiate into the definitiveendoderm and mesoderm during gastrulation. However, the developmental mechanisms at the end of gastrulation have not yetbeen elucidated. Histological and genetic analyses of the ventral ectodermal ridge (VER), a derivative of the primitive streak, wereperformed using chick and mouse embryos. The analyses showed a continued cell movement resembling gastrulation associatedwith EMT during the early tailbud stage of both embryos. Such gastrulation-like cell movement was gradually attenuated by theabsence of EMT during tail development. The kinetics of the expression pattern of noggin (Nog) and basal membrane degradationadjacent to the chick and the mouse VER indicated a correlation between the temporal and/or spatial expression of Nog and thepresence of EMT in the VER. Furthermore, Nog overexpression suppressed EMT and arrested ingressive cell movement in the chickVER. Mice mutant in noggin displayed dysregulation of EMT with continued ingressive cell movement. These indicate that theinhibition of Bmp signaling by temporal and/or spatial Nog expression suppresses EMT and leads to the cessation of the ingressivecell movement from the VER at the end of gastrulation

    Formation of an Ultracarbonaceous Antarctic Micrometeorite through Minimum Aqueous Alteration in a Small Porous Icy Body

    Get PDF
    A comprehensive study of the organic chemistry and mineralogy of an ultracarbonaceous micrometeorite (UCAMM D05IB80) collected from near the Dome Fuji Station, Antarctica, was carried out to understand the genetic relationship among organic materials, silicates, and water. The micrometeorite is composed of a dense aggregate of ∼5 µm-sized hollow ellipsoidal organic material containing submicrometer-sized phases such as glass with embedded metal and sulfides (GEMS) and mineral grains. There is a wide area of organic material (∼15 × 15 μm) in its interior. Low-Ca pyroxene is much more abundant than olivine and shows various Mg/(Mg + Fe) ratios ranging from ∼1.0 to 0.78, which is common to previous works on UCAMMs. By contrast, GEMS grains in this UCAMM have unusual chemical compositions. They are depleted in both Mg and S, which suggests that these elements were leached out from the GEMS grains during very weak aqueous alteration, without the formation of phyllosilicates. The organic materials have two textures—smooth and globular with an irregular outline—and these are composed of imine, nitrile and/or aromatic nitrogen heterocycles, and amide. The ratio of nitrogen to carbon (N/C) in the smooth region of the organics is ∼0.15, which is five times higher than that of insoluble organic macromolecules in types 1 and 2 carbonaceous chondritic meteorites. In addition, the UCAMM organic materials are soluble in epoxy and are thus hydrophilic; this polar nature indicates that they are very primitive. The surface of the material is coated with an inorganic layer, a few nanometers thick, that consists of C, O, Si, S, and Fe. Sulfur is also contained in the interior, implying the presence of organosulfur moieties. There are no isotopic anomalies of D, 13C, or 15N in the organic material. Interstellar photochemistry alone would not be sufficient to explain the N/C ratio of the UCAMM organics; therefore, we suggest that a very small amount of fluid on a comet must have been necessary for the formation of the UCAMM. The GEMS grains depleted in Mg and S in the UCAMM prove a very weak degree of aqueous alteration; weaker than that of carbonaceous chondrites. Short-duration weak alteration probably caused by planetesimal shock locally melted cometary ice grains and released water that dissolved the organics; the fluid would likely have not mobilized because of the very low thermal conductivity of the porous icy body. This event allowed the formation of the large organic puddle of the UCAMM, as well as organic matter sulfurization, formation of thin membrane-like layers of minerals, and deformation of organic nanoglobules.アクセプト後にタイトル・アブストラクト等変更あり、著者最終稿は変更前のタイトル"Formation of an Ultracarbonaceous Antarctic Micrometeorite through Minimum Aqueous Alteration in a Small Porous Icy Body"This work was supported by a Grant-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology (No. 22224010, PI: H. Nagahara). The STXM facility at the beamline 5.3.2.2, ALS, is supported by the Department of Energy, Basic Energy Sciences Program

    Usefulness of Endoscopic Managements in Patients with Ceftriaxone-Induced Pseudolithiasis Causing Biliary Obstruction

    Get PDF
    Ceftriaxone (CTRX) is known to cause reversible biliary stones/sludge, which is called biliary pseudolithiasis. We report two rare cases of biliary obstruction by pseudolithiasis shortly after completing CTRX treatment. Stones and sludge, which had not been detected before CTRX administration, appeared in the gallbladder and common bile duct and led to biliary obstruction and acute cholangitis. The obstructions were successfully treated with endoscopic retrograde biliary drainage and endoscopic sphincterotomy. CTRX-induced biliary pseudolithiasis has been reported mainly in children and adolescents but is also seen in adults with similar incidence rate. Although CTRX-induced biliary pseudolithiasis is usually asymptomatic and disappears spontaneously after discontinuing the drug, some patients develop biliary obstruction. Endoscopic managements should be considered in such cases
    corecore