Search results for "hepatica"
showing 10 items of 101 documents
Extracellular Vesicles From the Helminth Fasciola hepatica Prevent DSS-Induced Acute Ulcerative Colitis in a T-Lymphocyte Independent Mode
2018
The complexity of the pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) has led to the quest of empirically drug therapies, combining immunosuppressant agents, biological therapy and modulators of the microbiota. Helminth parasites have been proposed as an alternative treatment of these diseases based on the hygiene hypothesis, but ethical and medical problems arise. Recent reports have proved the utility of parasite materials, mainly excretory/secretory products as therapeutic agents. The identification of extracellular vesicles on those secreted products opens a new field of investigation, since they exert potent immunomodulating effects. To assess the ef…
Fasciola spp: Mapping of the MF6 epitope and antigenic analysis of the MF6p/HDM family of heme-binding proteins
2017
MF6p/FhHDM-1 is a small cationic heme-binding protein which is recognized by the monoclonal antibody (mAb) MF6, and abundantly present in parenchymal cells and secreted antigens of Fasciola hepatica. Orthologs of this protein (MF6p/HDMs) also exist in other causal agents of important foodborne trematodiasis, such as Clonorchis sinensis, Opisthorchis viverrini and Paragonimus westermani. Considering that MF6p/FhHDM-1 is relevant for heme homeostasis in Fasciola and was reported to have immunomodulatory properties, this protein is expected to be a useful target for vaccination. Thus, in this study we mapped the epitope recognized by mAb MF6 and evaluated its antigenicity in sheep. The sequenc…
On the presence and immunoregulatory functions of extracellular microRNAs in the trematode Fasciola hepatica.
2017
Summary Liver flukes represent a paraphyletic group of endoparasitic flatworms that significantly affect man either indirectly due to economic damage on livestock or directly as pathogens. A range of studies have focussed on how these macroscopic organisms can evade the immune-system and live inside a hostile environment such as the mammalian liver and bile-ducts. Recently, microRNAs, a class of short non-coding gene-regulators, have been proposed as likely candidates to play roles in this scenario. MicroRNAs (miRNAs) are key players in development and pathogenicity and are highly conserved between metazoans: identical miRNAs can be found in flatworms and mammalians. Interestingly, miRNAs a…
Potential Influence of Helminth Molecules on COVID-19 Pathology
2020
In recent months, the parasitology research community has been tasked with investigation of the influence of parasite coinfection on coronavirus disease 2019 (COVID-19) outcomes. Herein, we share our approach to analyze the effect of the trematode Fasciola hepatica as a modulator of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and of COVID-19 pathology.
Isolation and Analysis of Fasciola hepatica Extracellular Vesicles
2020
The finding of extracellular vesicles (EVs) as important players in parasite-parasite and host-parasite communications has led to an increasing number of reports in the literature. Different protocols have been developed for isolation and further characterization of EVs from parasitic helminths. In this chapter, we describe step by step procedures to isolate EVs secreted by Fasciola hepatica adults in culture, which could be also applied for other developmental stages of the parasite, as well as EVs present in plasma and urine. Along with classical isolation methods like differential ultracentrifugation, and more recent techniques like size exclusion chromatography (SEC), here we also refer…
Fluke egg characteristics for the diagnosis of human and animal fascioliasis by Fasciola hepatica and F. gigantica
2009
In trematodiases, shape and size of the fluke eggs shed with faeces are crucial diagnostic features because of their typically reduced intraspecific variability. In fascioliasis, the usual diagnosis during the biliary stage of infection is based on the classification of eggs found in stools, duodenal contents or bile. The aim of the present study is to validate the identification of Fasciola species based on the shape and size of eggs shed by humans, characterizing their morphometric traits using a computer image analysis system (CIAS). The influence of both the geographical location and of the host (human and livestock) has been analysed. Coprological studies were carried out in fasciolias…
Assessment of blood coagulation in severe liver disease using thromboelastography: use of citrate storage versus native blood.
2003
Thromboelastography evaluates the viscoelastic properties of blood coagulation. Using native blood, measurement must start soon after sampling. With normal coagulation, native and citrated blood values correlate well. No data exists from cirrhotic patients. We compared native and citrate thromboelastography parameters in 30 cirrhotic patients (20 Child-Pugh C class, two liver failure). Thromboelastography was performed within 4 min using native blood and after recalcification within 1-2 h of citrate storage. Thromboelastography variables (r, a, k, ma) were compared using the Mann-Whitney test, correlation investigated with the Pearson method and the degree of agreement with the Bland-Altman…
A population-based coprological study of human fascioliasis in a hyperendemic area of the Bolivian Altiplano
1997
The community of Chijipata Alta, at an altitude of 3850 m, near the southern coast of Lake Titicaca in the Northern Altiplano of Bolivia, was surveyed for human fascioliasis. The global prevalence (66.7 %) and intensity (eggs per gram of faeces - epg: range: 24-4440; arithmetic mean: IooI; geometric mean: 390) proved to be the highest known in the world by means of coprological techniques. These results suggest the existence of highly hyperendemic subzones among the large human fascioliasis-endemic zone of the Bolivian Northern Altiplano. Despite the decrease in prevalence and intensity from children (75.0%, 24-4440 epg) to adults (41.7%, 144-864 epg), our findings show that in an hyperende…
Hyperendemic fascioliasis associated with schistosomiasis in villages in the Nile Delta of Egypt.
2003
Coprologic surveys were carried out in villages of the Behera Governorate in the Nile Delta region of Egypt to characterize the epidemiologic features of human fascioliasis caused by Fasciola hepatica and F. gigantica in this lowland endemic area by comparison with fascioliasis caused by only F. hepatica in areas hyperendemic for human disease in the Andean highlands of South America. The fascioliasis prevalences detected (range = 5.2-19.0%, mean = 12.8%) are the highest obtained in Egypt. The comparison with previous results suggests that in the Nile Delta, fascioliasis is spreading from an original situation of sporadic human cases in well-known endemic foci for animal disease to an endem…
High endemicity of human fascioliasis between Lake Titicaca and La Paz valley, Bolivia.
1999
Over a 6-year period, an epidemiological study of human infection by Fasciola hepatica in the Northern Bolivian Altiplano was carried out. Prevalences and intensities were analysed from coprological results obtained in 31 surveys performed in 24 localities and proved to be the highest known so far. The global prevalence was 15.4%, with local prevalences ranging from 0% to 68.2%. Significant differences between prevalence rates were detected and the highest prevalences were in subjects aged20 years. However, prevalences showed no gender difference. The global intensity (eggs per gram of faeces, epg) ranged from 24 to 5064 epg and showed arithmetic and geometric means respectively of 446 and …