Parasite Behaviour: Understanding Platyhelminth Responses

Sukhdeo, M. V. K.; Mettrick, D. F.

doi:10.1016/s0065-308x(08)60295-x

Cited by 68 publications

(33 citation statements)

References 274 publications

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“…Acetylcholine, 5-hydroxytryptamine (5-HT) and glutamate have been localized in cestodes (Webb & Eklove, 1989;Samii & Webb, 1990;Solis & De Jong, 1994;Brownlee et al, 1994;Fairweather et al, 1994;Terenina et al, 1998) and there is a consensous that acetylcholine acts as the inhibitory neurotransmitter (Thompson & Mettrick, 1984;Sukhdeo & Mettrick, 1987), 5HT and glutamate stimulate the motility in cestodes working as the excitatory neurotransmitters (Sukhdeo & Mettrick, 1987;Webb & Eklove, 1989) and they have an activating effect on metabolism (Thompson & Mettrick, 1984). It is known that acetylthiocholine is degraded into thiocholine and acetate by means of acetylcholinesterase (AchE) activity (Ellman et al, 1961).…”

Section: Mots Clés : Cholinestérases Echinococcus Granulosus Protosmentioning

confidence: 99%

Presence of cholinesterases inEchinococcus granulosusprotoscolices

et al. 2000

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Summary:Cholinesterases were detected in protoscolices of Echinococcus granulosus spectrophotometrically and electrophoretically. To characterize these activities as acetylcholinesterases or pseudocholinesterases, BW284C51 and the organophosphate anthelmintic Neguvón® were assayed as specific inhibitors of acetylcholinesterases, while Iso-OMPA was employed as specific inhibitor of pseudocholinesterases. We concluded that these Cholinesterase (ChE) activities would be considered as possible targets in chemotherapy. KEY WORDS : cholinesterases, Echinococcus granulosus, protoscolices. Résumé : PRÉSENCE DE CHOLINESTÉRASES AU NIVEAU DU PROTOSCOLEX D'ECHINOCOCCUS GRANULOSUS Des cholinestérasesont été détectées par spectrophotométrie et

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Section: Mots Clés : Cholinestérases Echinococcus Granulosus Protosmentioning

confidence: 99%

Presence of cholinesterases inEchinococcus granulosusprotoscolices

et al. 2000

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“…A parasite's affinity or specificity for particular tissue/organs sites may result from a number of factors that may be driven by the specific nutritional and/or environmental requirements of the parasite (Crompton 1976), the consequences of inter-specific competition for resources and subsequent niche separation between species (Holmes & Price 1985), or by attempts to evade the host's chemical and cellular immune defences (Price 1987, Sukhdeho & Mettrick 1987, Sukhdeho & Sukhdeho 1994.…”

Section: Introductionmentioning

confidence: 99%

Histopathological and ultrastructural observations of metacercarial infections of Diplostomum phoxini (Digenea) in the brain of minnows Phoxinus phoxinus

Dezfuli¹,

Capuano²,

Simoni³

et al. 2007

Dis. Aquat. Org.

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The spatial distribution and histopathological changes induced by metacercariae of the digenean trematode Diplostomum phoxini (Faust, 1918) in the brains of European minnows Phoxinus phoxinus (L.) from the River Endrick, Scotland, were studied by light and electron microscopy. Postmortem examination of a sample of 34 minnows revealed that 50% (n = 17) of the population was infected with 13.7 ± 2.6 (mean ± SE; range 1 to 38) metacercariae per infected host. Serial histological sections of the infected minnow brains revealed that the metacercariae were unevenly distributed throughout the brain, with aggregations occurring in the cerebellum, the medulla oblongata and the optic lobes. In fish with highest intensities of infection, over 40% of the cerebellar area and about 30% of the medulla oblongata area were occupied by larvae. Metacercariae disrupt the integrity of brain tissue, with individuals being found in small pockets surrounded by cellular debris. Metacercariae were rarely encountered on the surface of the brain. Electron microscopic examination of infection sites revealed that the granular layer surrounding metacercariae was necrotic, exhibited nuclear degradation and was marked by vacuolation of the cytoplasm. Rodlet cells, the only inflammatory cell types recorded in this study, were found only in parasitized brains and in close proximity to the teguments of metacercariae. It is hypothesised that secretions released from the teguments of metacercariae are a counter response to protect the metacercariae from the fish brain's cellular defence mechanisms. KEY WORDS: Brain infection · Digenean trematode · Phoxinus phoxinus · Rodlet cells · Histopathology · Ultrastructure Resale or republication not permitted without written consent of the publisherDis Aquat Org 75: [51][52][53][54][55][56][57][58][59] 2007 gata and the optic lobes, centres of the brain that are responsible for host motor activity, sensory functions and vision (Barber et al. 2000, Shirakashi & Goater 2005. Until recently, metacercariae were generally regarded as immature, non-feeding and metabolically inactive stages waiting for transmission to the next/ definitive host (Bush et al. 2001, Poulin & Latham 2003. However, a recent study by Goater et al. (2005) demonstrated via experimental infection that the metacercariae of Ornithodiplostomum ptychocheilus Faust, 1917 in Pimephales promelas Rafinesque, 1820 undergo a series of complex developmental changes associated with their feeding on host brain tissue.A histological examination of Phoxinus phoxinus heads in the current study revealed the presence of rodlet cells only in infected brains, notably in the epithelium lining the ventricles of the optic lobes. It is believed that rodlet cells play a role within the piscine inflammatory response (Dezfuli et al. 2000, Manera & Dezfuli 2004, Reite 2005, Reite & Evensen 2006. We found rodlet cells only within the infected brain of a fish, and our findings are briefly compared with the information available on their presence in other f...

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“…Many studies have dealt with miracidial and cercarial behavior and, in fact, most of the described behavioral patterns can be interpreted as adaptations to successful invasion of the hosts (reviewed by Ulmer, 1971;Cable, 1972;Erasmus, 1972;MacInnis, 1976;Saladin, 1979;Christensen, 1980;Sukhdeo and Mettrick, 1987;Haas, 1992;Combes et al, 1994;Haas et al, 1995a;Haberl, 1995;Haas and Haberl, 1997). They are provided with limited energy reserves, which allow them only for few hours of full activity.…”

Section: Functions Of Miracidial and Cercarial Behaviormentioning

confidence: 99%

Echinostomes as Experimental Models for Biological Research

Fried¹,

Graczyk²

2000

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Parasite Behaviour: Understanding Platyhelminth Responses

Cited by 68 publications

References 274 publications

Presence of cholinesterases inEchinococcus granulosusprotoscolices

Presence of cholinesterases inEchinococcus granulosusprotoscolices

Histopathological and ultrastructural observations of metacercarial infections of Diplostomum phoxini (Digenea) in the brain of minnows Phoxinus phoxinus

Echinostomes as Experimental Models for Biological Research

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