Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CESTODE INFECTIONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56Linked to original sources
PubMed1992

A double surface membrane in plerocercoids of Ligula intestinalis (Cestoda: Pseudophyllidea).

The tegument of Ligula intestinalis plerocercoids is delimited by a membrane complex that in electron microscopy appears heptalaminate. We suggest that the plerocercoids are covered by two closely apposed lipid bilayers. Double membranes, which are well known in schistosomes, are thus not a unique feature of blood parasitic Digenea but could be documented for the first time in a cestode species that lives in the peritoneal cavity of its host. The surface-membrane complex of plerocercoids was lost for the most part after conventional preparation for electron microscopy but could be completely retained by improved fixation using osmium tetroxide plus potassium ferrocyanide. Furthermore, one type of vesicle in the tegumental syncytium of plerocercoids has been found to be enclosed by at least two membranes, which might indicate that these vesicles contribute to the renewal of the surface-membrane complex. Adult Ligula intestinalis removed from the gut of the final host Anas platyrhnychos or obtained by in vitro transformation exhibited a single surface membrane and lacked double membrane vesicles. The elongate electron-dense caps of the microtriches of plerocercoids were replaced by short caps in the course of worm maturation. Thus, the tegumental surface of this parasite is fundamentally altered following the change in its environment from the peritoneal cavity of the intermediate host to the intestine of the final host.

Animals↗
PubMed1989

Observations on the lipids of Oochoristica agamae (Cestoda).

An investigation of the lipids of Oochoristica agamae, an anoplocephalid cestode of the Agama lizard, was undertaken. Total lipids of the parasite accounted for 8.4% of the fresh weight; neutral lipids comprised 82.98% of the total, glycolipids, 5.01%, and phospholipids, 12.03%. The major lipid classes in O. agamae include triglycerides, cholesterol, phosphatidyl choline, and phosphatidyl ethanolamine. The 16- and 18-carbon fatty acids were predominant in the parasite. Hexadecenoic acid, usually found at low concentrations in the lipids of helminth parasites, was the most abundant of the 16-carbon fatty acids of O. agamae (notably in the neutral lipid fraction). Although octadecatrienoic acid occurred only in trace amounts in the intestinal contents of the host, significant amounts of this fatty acid were detected in the parasite. A lack of 20-carbon fatty acids was determined in the lipids of the host's intestinal contents and the neutral lipid fraction of the parasite. O. agamae is suspected to be capable of modifying fatty acids obtained from dietary sources by chain elongation.

Animals↗
PubMed1991

Ultrastructure of the excretory system of Trilocularia acanthiaevulgaris (Cestoda, Tetraphyllidea).

The fine structure of the excretory system in the juvenile (plerocercoid-like) form of Trilocularia acanthiaevulgaris is described. The flame cell bears a bunch of 50-70 cilia, which are anchored in the cytoplasm by means of basal bodies possessing striated rootlets. All the cilia in the "flame" are aligned in the same direction. The flame and duct cells are connected by interdigitating ribs of cytoplasm separated by a fibrous sheet. Both internal and external leptotriches are also present. The lumen of the excretory ducts is intracellular in origin. The apical surface of the cytoplasm lining the duct is convoluted and its surface area is further amplified by means of microvilli. The fine structure of the excretory system in this primitive tapeworm is compared with that described for other parasitic and free-living flatworms.

Animals↗
PubMed2004

Gastrointestinal parasite infestation.

Twenty-five percent of the world's population could be suffering parasitic infestation. Highest prevalence is in underdeveloped agricultural and rural areas in the tropical and subtropical regions. In some areas incidence may reach 90% of the population. In contrast, some major economic projects intended to promote local development have, paradoxically, caused parasitic proliferation, e.g. bilharziasis in Egypt and Sudan and Chagas disease in Brazil. The commonest cosmopolitan gastrointestinal parasite is Entamoeba histolytica. Some intestinal parasite are endemic in temperate climates, e.g. Entrobius vermicularis. The AIDS epidemic has increased the prevalence and severity of parasitic disease, particularly Strongyloides stercolaris. Tropical parasites are seen in Western people who travel to tropical countries. Radiology has acquired a major role in diagnosis and management of gastrointestinal parasite infestations and their complications.

Animals↗
PubMed2002

Asexual multiplication of larval parasitic worms: a predictor of adult life-history traits in Taeniidae?

The hypothesis that asexual multiplication inside the intermediate host and adult life-history traits within the final host are independent is tested among Cestoda. Using phylogenetic relationships among the Cestoda species, we can show that asexual multiplication appears to have been lost and recovered several times throughout Taeniidae evolution; this allows a comparison of the adult life-history traits of species with and without asexual multiplication at the larval stage. The adult trait considered is the size of the parasite, since numerous life-history traits, such as fecundity and longevity, are correlated with size. If adult traits are independent of whether the larval stage reproduced asexually or not, we expect no difference in the adult size of the proliferative (i.e. with asexual multiplication) and non-proliferative species. The results are inconsistent with this hypothesis. In contrast, species with asexual multiplication in the intermediate host seem to have smaller adult size, reflecting a trade-off. We propose that ecological factors involving intraspecific and interspecific competition in the final host might be responsible for this trade-off. The role of these parameters in the evolution of life-history traits and more precisely in the acquisition of asexual multiplication is investigated with comparative analysis and discussed in the context of host-parasite interactions.

Animals↗
PubMed2002

Ultrastructure of the spermatozoon of the proteocephalidean cestode Proteocephalus torulosus (Batsch, 1786).

The fine structure of the mature spermatozoon of the proteocephalidean tapeworm Proteocephalus torulosus, a parasite of cyprinid fishes, was studied by transmission electron microscopy for the first time. The mature spermatozoon of P. torulosus is filiform and tapered at both extremities. It contains two axonemes of the 9+"1" type and of unequal length. The anterior extremity of the spermatozoon bears a helicoidal crested body approximately 100 nm thick. Cortical microtubules of two types lie parallel to the spermatozoon axis. The nucleus is a fine cord of condensed chromatin. The slightly electron-dense cytoplasm contains electron-dense granules in regions II and III of the spermatozoon. The anterior and posterior extremities of the spermatozoon contain a single axoneme. The mature spermatozoon of P. torulosus differs from that of other Proteocephalusspecies in the presence of a single crested body and in the morphology of its posterior end.

Animals↗
PubMed2002

Comparative karyological analysis of three species of Bothriocephalus Rudolphi 1808 (Cestoda: Pseudophyllidea).

The diploid complements of mitotic metaphase plates of three species of Botriocephaluswere studied using conventional Giemsa staining and karyometric analysis. Botriocephalus claviceps and Botriocephalus gregarius showed a karyotype with 2n=14 chromosomes. All chromosomes of B. claviceps were biarmed, metacentric or meta-submetacentric. The two first pairs of homologues were markedly larger than the remaining elements and represented 48.62% of the total chromosome length. The karyotype of B. gregarius had similar metric values for the chromosomes, but clearly differed in the chromosome morphology of pairs 5, 6 and 7, which had terminally located centromeres. The diploid number 2n=12 was found in Botriocephalus scorpii. The karyotype consists of five pairs of metacentric and one pair of submeta-metacentric chromosomes. The possible pathways of karyotype evolution within Bothriocephalus spp. and their phylogenetic relations with the other karyologically studied groups in the order Pseudophyllidea are discussed.

Anguilla↗