Search results for "Helminth"
showing 10 items of 363 documents
Echinostoma caproni (Trematoda): differential in vivo cytokine responses in high and low compatible hosts.
2011
In order to investigate the factors determining the expulsion of intestinal trematodes, we have analyzed the in vivo cytokine responses at several levels and the local responses against Echinostoma caproni (Trematoda) in two host species displaying different compatibility with the parasite. The response of the high compatible host (mice) is characterized by a mixed Th1/Th2 phenotype in the spleen, Peyer's patches and mesenteric lymph nodes. At the intestine, a marked Th1 response with a marked increase of IFN-γ together with elevated number of mucosal neutrophils and expression of induced nitric oxide synthase were observed. The responses in the host of low compatibility (rats) with the par…
UNC-52/perlecan affects gonadal leader cell migrations in C. elegans hermaphrodites through alterations in growth factor signaling.
2003
0012-1606 doi: DOI: 10.1016/S0012-1606(03)00014-9; The unc-52 gene of Claenorhabditis elegans encodes a homologue of the basement membrane heparan sulfate proteoglycan perlecan. Viable alleles reduce the abundance of UNC-52 in late larval stages and increase the frequency of distal tip cell (DTC) migration defects caused by mutations disrupting the UNC-6/netrin guidance system. These unc-52 alleles do not cause circumferential DTC migration defects in an otherwise wild-type genetic background. The effects of unc-52 mutations on DTC migrations are distinct from effects on myofilament organization and can be partially suppressed by mutations in several genes encoding growth factor-like molecu…
Echinostoma caproni: Differential tegumental responses to growth in compatible and less compatible hosts
2010
Abstract The topography of the tegument of Echinostoma caproni adults collected from high (mice) and low (rats) compatible hosts was compared by SEM. In the oral (OS) and the ventral sucker (VS) areas, a worm age–host species interaction was found with regard to the density of spines. There was a decrease in the density of spines in the adults collected from mice, whereas an increase occurred in the OS area in worms from rats over time. The tegumentary spines in adults from mice became larger and blunter. Some spines from the VS area in adults from mice at 4 wpi were multipointed. The spines of adults from rats were sharper, not covered by the tegument and no multipointed spines were observ…
Special considerations for studies of extracellular vesicles from parasitic helminths: A community-led roadmap to increase rigour and reproducibility.
2023
Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross-species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well-recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth-derived EVs in these processes and highlights EVs as an important participant in cross-phylum communication. While the mammalian EV field is guided by a community-agreed framework for studying EVs derived from model organisms or cell systems [e.g., Minimal Information for Studies of Extracellular Vesicles (MISEV)], the helminth community requires a supplem…
The predictability of helminth community structure in space: a comparison of fish populations from adjacent lakes
2002
Patterns in helminth community structure can suggest that various processes are acting to shape parasite communities into organised, non-random assemblages of species. It is not clear, however, whether a pattern observed in one host population at one time would be observed again at another time, or at the same time in a different but comparable host population. Here, we test the repeatability of parasite community structure in space, and to a lesser extent time, with data on helminth parasites of two fish species, perch Perca fluviatilis and roach Rutilus rutilus, collected in different seasons from four adjacent lakes in Central Finland. Since populations of the same fish species harbour t…
The helminth community of the Iberian hare, Lepus granatensis (Lagomorpha: Leporidae), in the province of Granada, Spain
2014
Abstract The helminth community of the Iberian hare, Lepus granatensis, in the southern Spanish province of Granada was analysed, thorough the study of 487 individuals shot by hunters between November 1998 and October 1999. Six helminth species were found: Mosgovoyia pectinata (Cestoda); Trichostrongylus retortaeformis, Nematodiroides zembrae, Nematodirus sp., Passalurus ambiguus and Micipsella numidica (Nematoda). N. zembrae and M. pectinata (62.4 % and 17.2 %, respectively) were the only component species found. The predominance of helminth species with a direct life cycle is noteworthy. These two component species were significantly influenced by season of capture. Other factors, such as…
Intestinal helminth communities of Podarcis bocagei and Podarcis carbonelli (Sauria: Lacertidae) in NW Portugal
2006
Abstract A survey of gastrointestinal helminth communities of Podarcis bocagei and Podarcis carbonelli (Sauria: Lacertidae) from NW Portugal was conducted to determine the prevalence, intensity and diversity of intestinal parasites in these lizards. A few parasite species were found in both hosts, their prevalences, mean intensities and abundances of infection being low or very low. Low values of richness and abundance of parasite species were also found in the helminth infracommunities of individuals of both host species. These low values of parameters of infection and diversity are discussed and compared between both host species and among other Iberian lacertid lizards.
Ecological Analysis of the Helminth Community of the Wood Mouse, Apodemus sylvaticus, along an 18-Year Post-Fire Regeneration Period in a Mediterrane…
2021
The role of helminths of the wood mouse, Apodemus sylvaticus, as biological indicators of the post-fire regeneration process in Serra Calderona Natural Park, a Mediterranean forest ecosystem located between the provinces of València and Castelló (Valencian Country, Spain), has been analysed for almost twenty years. The helminth ecological analysis of 917 A. sylvaticus (675 originating from the burned area and 242 originating from the control area) has been carried out between the 2nd and 18th post-fire years. The influence of intrinsic (host population density, sex and age) and extrinsic (site, period and year of capture, climate variables) factors on the post-fire evolution of the helminth…
Molecular and morphological identification of larval opecoelids (Digenea: Opecoelidae) parasitising prosobranch snails in a Western Mediterranean lag…
2012
In a study of the digeneans parasitising molluscs in the Els Alfacs lagoon (Ebro Delta, Western Mediterranean) we found heavy infections with sporocysts emitting two types of cotylocercous cercariae in the prosobranch trochid gastropod Gibbula adansonii and with metacercariae in the prosobranch nassariid gastropod Cyclope neritea. A comparative analysis using ITS ribosomal DNA sequences from these larval stages and published sequences of 17 larval and adult opecoelid stages allowed us to elucidate the life-cycle of Macvicaria obovata and to confirm the identification of Cainocreadium labracis based on cercarial morphology. We provide molecular evidence for the identification and the first d…
A comparison of the structure of helminth communities in the woodmouse, Apodemus sylvaticus, on islands of the western Mediterranean and continental …
2003
We investigated the pattern of helminth species diversity in woodmouse, Apodemus sylvaticus, on western Mediterranean islands. We first performed a survey of the helminth fauna of A. sylvaticus in Sicily. Despite the small sampling effort, parasite species richness in Sicily is large in comparison with parasite species richness on other Mediterranean islands. We tested the nestedness of helminth parasite species from a number of Mediterranean localities using data compiled from epidemiological surveys of the helminth species of A. sylvaticus. We showed a nested pattern for woodmouse helminth species on western Mediterranean islands which suggests that the distribution of parasites on these …