Search results for "host"
showing 10 items of 1982 documents
Reviewing lymnaeid vectors of fascioliasis by ribosomal DNA sequence analyses.
2005
AbstractSnails of the family Lymnaeidae are of great parasitological importance due to the numerous helminth species they transmit, mainly trematodiases (such as fascioliasis) of considerable medical and veterinary impact. The present knowledge of the genetics and host–parasite relationships of this gastropod group is far from adequate. Fascioliasis is caused by two species, Fasciola hepatica and F. gigantica, which, as in the case of other trematodes, show a marked snail host specificity. Many lymnaeid species involved in fascioliasis transmission still show a confused systematic-taxonomic status. The need for tools to distinguish and characterize species and populations of lymnaeids is ev…
Echinostomes: systematics and life cycles
2008
This chapter provides a review of the most significant literature in the last decade on the systematics and biology of echinostomes and echinostome-like digeneans. This review is primarily concerned with members of the genus Echinostoma, although members of other genera (Echinoparyphium, Echinochasmus, Himasthla, Hypoderaeum, Petasiger, Euparyphium, Stephanoprora, Isthmiophora, and Acanthoparyphium) and echinostome-related genera (Parorchis, Philophthalmus and Ribeiroia) are also considered. The literature on molecular systematics and morphometrics of these trematodes is reviewed. Specific mention is made of the life cycle patterns of echinostome and echinostome-like digeneans along with an…
Chapter 3 Recent Advances in the Biology of Echinostomes
2009
This chapter examines the significant literature on the biology of echinostomes. The members of the family Echinostomatidae are medically and veterinary-important parasitic flatworms that invade humans, domestic animals and wildlife and also parasitize in their larval stages numerous invertebrate and cold-blooded vertebrate hosts. All echinostomes possess a complicated lifecycle expressed by: (i) alternation of seven generations known as the adult, egg, miracidium, sporocyst, redia, cercaria and metacercaria, and (ii) inclusion of three host categories known as the definitive host and first and second intermediate hosts. Moreover, echinostomes have served as experimental models in parasitol…
Skin Dendritic Cells in Murine Cutaneous Leishmaniasis
2002
Studies of the immunopathogenesis of Leishmania major-induced murine cutaneous leishmaniasis provide a framework for understanding the evolution of L. major infection of skin in humans and the foundation for rationale vaccine design. Experiments in which infection is initiated with "suprap hysiologic" numbers of parasites clearly identify Th-derived type I cytokines as essential participants in macrophage activation and macrophage nitric oxide production as prerequisite for parasite control. Dendritic cells, rather than macrophages, appear to be responsible for L. major-specific Th priming in these studies. Recent studies of murine cutaneous leishmaniasis in a model system in which infectio…
Intrahepatic myeloid-cell aggregates enable local proliferation of CD8+T cells and successful immunotherapy against chronic viral liver infection
2013
Chronic infection is difficult to overcome because of exhaustion or depletion of cytotoxic effector CD8(+) T cells (cytotoxic T lymphoytes (CTLs)). Here we report that signaling via Toll-like receptors (TLRs) induced intrahepatic aggregates of myeloid cells that enabled the population expansion of CTLs (iMATEs: 'intrahepatic myeloid-cell aggregates for T cell population expansion') without causing immunopathology. In the liver, CTL proliferation was restricted to iMATEs that were composed of inflammatory monocyte-derived CD11b(+) cells. Signaling via tumor-necrosis factor (TNF) caused iMATE formation that facilitated costimulation dependent on the receptor OX40 for expansion of the CTL popu…
Role of IFN-gamma in immune responses to Candida albicans infections
2014
Candida albicans is the most frequent etiologic agent that causes opportunistic fungal infections called candidiasis, a disease whose systemic manifestation could prove fatal and whose incidence is increasing as a result of an expanding immunocompromised population. Here we review the role of interferon-gamma (IFN-γ) in host protection against invasive candidiasis. This cytokine plays an essential role in both the innate and adaptive arms of the immune response to candidiasis. We focus on recent progress on host-pathogen interactions leading to the production of IFN-γ by host cells. IFN-γ is produced by CD4 Th1, CD8, γδ T, and natural killer (NK) cells, essentially in response to both IL-12…
Primary in vivo T cell reactivity of NZB grafts in H-2 identical allogenic hosts.
1983
By means of the Simonson GVH-assay and the popliteal lymph node (PLN) assay, the T-cell reactivity of NZB mice against H-2 identical allogenic cells was investigated in vivo and compared to that of normal mice. None of the normal mice did react, but a highly significant NZB response could be demonstrated, which did not depend on differences in Mls antigens. These in vivo results extend previous findings of a T-cell hyperreactivity of NZB mice in primary in vitro reactions. They favour the possibility that the T-cell hyperreactivity might be relevant in vivo in facilitating autoimmune responses.
Host immune response to Cryptosporidium parvum infection
2010
Species of the genus Cryptosporidium are protozoan parasites (Apicomplexa) that cause gastroenteritis in animals and humans. Of these Cryptosporidium parvum and Cryptosporidium hominis are the major causative agents of human cryptosporidiosis. Whereas infection is self-limiting in the immunocompetent hosts, immunocompromised individuals develop a chronic, life-threatening disease. As specific therapeutic or preventive interventions are not yet available, better understanding of the immune response to the parasite is required. This minireview briefly summarizes the factors involved in the innate and acquired immune response in this pathogen-host interaction with an emphasis on more recent da…
Diphenylsulfone-based hosts for electroluminescent devices: Effect of donor substituents
2020
DG acknowledges to the ERDF PostDoc project No. 1.1.1.2/VIAA/1/16/177. This work was supported by the project of scientific co-operation program between Latvia, Lithuania and Taiwan ?Polymeric Emitters with Controllable Thermally Activated Delayed Fluorescence for Solution-processable OLEDs? (grant No. S-LLT-19-4). Support of the Lithuanian Academy of Sciences is gratefully acknowledged; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²
Solar photovoltaic‑based microgrid hosting capacity evaluation in electrical energy distribution network with voltage quality analysis
2021
Abstract In this paper, solar photovoltaic hosting capacity within the electrical distribution network is estimated for different buses, and the impacts of high PV penetration are evaluated using power hardware-in-loop testing methods. It is observed that the considered operational constraints (i.e. voltage and loadings) and their operational limits have a significant impact on the hosting capacity results. However, with increasing photovoltaic penetration, some of the network buses reach maximum hosting capacity, which affects the network operation (e.g. bus voltages, line loading). The results show that even distributing the maximum hosting capacity among different buses can increase the…