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At least 1,153 records · Page 64Linked to original sources
PubMed1981

[Contribution to the knowledge of Taenia crassiceps (Zeder, 1800) Rudolphi, 1810 (Cestoda, Taeniidae) (author's transl)].

The occurrence of Taenia crassiceps in naturally infected dogs is mentioned, and a brief description of the gravid proglottids is given. Oral infection of several rodent species with eggs showed that the field vole (Microtus arvalis) is the most susceptible intermediate host for this tapeworm. The cysticercus often develops in the brain of the rodent and causes disturbances of coordinated movements. Two foxes (Vulpes vulpes) were infected with cysticerci of the strains COLA and GIKS. These strains were originally isolated from two dogs. The foxes passed fertile eggs and proglottids as early as 31 and 32 days respectively after infection.

Animals↗
PubMed1985

Hymenolepis diminuta: a comparison between young developing, and small, destrobilated worms in the rat intestine.

Newly in vitro excysted tapeworms of Hymenolepis diminuta (Cestoda, Cyclophyllidea), 1- to 3-day-old worms and destrobilated worms from rat intestines were investigated by means of light microscopy (LM) and scanning electron microscopy (SEM). It was found that the scolex of 1- and 2-day-old worms had shallow suckers with smooth brims, while 3-day-old and older worms, including destrobilated worms, had deep suckers with puckered brims. The posterior end of 1- and 2-day-old worms had a central cone-shaped structure not present in 3-day-old and older, or destrobilated worms. The repairing of the posterior end and the protonephridial system after excystation or destrobilation was much the same. Tissue remnants moved into the centre of the posterior end, resulting in an indentation with a pore to the exterior. The indentation and its pore became connected to the emptying canals of the protonephridial system, i.e. they developed into the excretory bladder and pore respectively.

Aging↗
PubMed1980

The common vole, Microtus arvalis Pall. as intermediate host of Mesocestoides (Cestoda) in Germany.

Tetrathyridia of Mesocestoides leptothylacus Loos-Frank, 1980 were found in 1.4% of 513 common voles (Microtus arvalis) in a district of Southwest Germany where foxes (Vulpes vulpes) are frequently infected with this tapeworm. The tetrathyridia measured 1 to 1.5 mm in length and 0.5 to 1 mm in width. When injected intraperitoneally into white mice, jirds, or common voles, the tetrathyridia did not multiply. Cats fed with the larvae shed proglottids from the 21st day onwards. In one experimentally infected silver-fox proglottids were passed from day 12 onwards. One human subject infected twice with tetrathyridia of M. leptothylacus, did not develop patent infections. One common vole from another district contained tetrathyridia of a Mesocestoides species, which is rarely found in indigenous foxes and which is characterized by a broad-oval cirrus pouch with a much convoluted cirrus.

Animals↗
PubMed1984

Helminth parasites of wild foxes (Vulpes vulpes L.) in The Netherlands.

To study the helminth fauna of wild foxes (Vulpes vulpes) in The Netherlands, material was collected from 139 foxes. The following parasites were found. Cestodes: Taenia spp. 53.3%, Hymenolepis spp. 1.5%; Trematodes: Alaria alata 10.9%, Cryptocotyle lingua 3.6%, Euparyphium melis 1.5%, Apophallus donicus 0.7%; Nematodes: Toxocara canis 73.7%, Uncinaria stenocephala 59.9%, Capillaria aerophila 46.8%, C. plica 23.5%, Molineus patens 5.1%, Crenosoma vulpis 4.5%, Strongyloides spp. 0.7%. The tapeworms Mesocestoides spp. and Echinococcus spp. were not seen. No relationship was observed between worm burden and sex, time of year or place of origin.

Animals↗
PubMed1985

The effect of trifluoperazine (Stellazine) on Hymenolepis diminuta in vitro.

The influence of the phenothiazine trifluoperazine (Stellazine) on the rat tapeworm Hymenolepis diminuta was examined. The parasite was incubated in glucose-containing Krebs-Ringer media (pH 7.4) at 37 degrees C which included Ca2+ or EGTA and a range of trifluoperazine concentrations (0-2 mM). Release of soluble protein and lactate dehydrogenase activity were taken as measures of release of cytosolic components. The release of lactate dehydrogenase depended on drug concentration, maximum levels occurring at 2 mM trifluoperazine, this corresponded to 2% of the total lactate dehydrogenase present in the cestode. The effect of phenothiazines of differing lipophilicity were compared, and for trifluoperazine sulfoxide only minimal amounts of lactate dehydrogenase activity and protein were released. These values were similar to those obtained when H. diminuta was incubated in drug-free media. Our findings suggest that the integrity of the parasite is related to its calmodulin content. The potential cestocidal properties of trifluoperazine are considered.

Animals↗
PubMed1990

The fine structure of the embryonic envelopes before and after hatching in bothriocephalids: physiological and ecological significance.

The fine structure and differentiation of the embryonic envelopes before and after hatching in two bothriocephalid species of teleostean fish are described. Scanning electron microscopic observation of the egg surface confirmed the specific ornamentation of the capsule. Its thickness and topographic morphology reflect the physiocochemical characteristics of the environment. Beneath the eggshell, two syncytial layers were observed around the oncosphere. The outer envelope, visible during the preoncospheral phase, degenerated before the liberation of the coracidium. Glycoconjugate labelling confirmed the nutritive character of this layer. After hatching, the inner envelope was the only layer covering the oncosphere. The apical plasma membrane of the coracidial sheath bore cilia and numerous clublike microvilli. Beneath the cortical zone, the syncytial cytoplasm was vacuolated, resembling a honeycomb; the electron-dense zone, described from other pseudophyllideans, was not present. The basal membrane of the inner envelope, uniformly electron-dense, was assimilated by the oncospheral membrane. Comparison of the composition of the embryonic envelopes of pseudophyllideans with those of other tapeworm orders and trematodes revealed ontogenetic, structural and functional similarities between the embryotrophic layers. The physiological and ecological significance of the structure of the free-swimming coracidium is discussed. In this respect, the inner envelope around the oncosphere appears to be responsible for the inability of the larva to detect and invade the intermediate host.

Animals↗
PubMed1990

An ontogenetic study of the cholinergic and serotoninergic nervous systems in Trilocularia acanthiaevulgaris (Cestoda, Tetraphyllidea).

The localisation and distribution of the cholinergic and serotoninergic components of the nervous system in the plerocercoid, adult and free proglottis stages of the tetraphyllidean tapeworm Trilocularia acanthiavulgaris were determined by enzyme histochemical and immunocytochemical techniques. The central nerve ring (CNR) in the scolex contains two lateral ganglia and gives rise to five pairs of longitudinal nerve cords (LNC's; three lateral, two median). The nerve cords run posteriorly throughout the bodies of the plerocercoid and adult worms and the free proglottis. Nerves from the CNR and accessory lateral LNC's pass to the bothridia, where they give rise to extensive nerve plexuses. As the individual proglottides develop along the strobila, a small nerve ring forms at the anterior end of each proglottis; within the nerve ring, distinct bilateral ganglia develop prior to the release of the proglottis. All ten LNC's are present in the free proglottis. The genital atrium and cirrus sac are innervated by cholinergic and serotoninergic elements. The cholinergic nervous system predominates in the CNS within the scolex, whereas there is a larger population of 5-HT-immunoreactive nerve cells associated with the LNC's and segmental ganglia along the strobila and within the free proglottis.

Animals↗
PubMed1993

Molecular modeling: a tool for predicting anthelmintic activity in vivo.

The structural and electronic features of the broad-spectrum benzimidazole anthelmintic mebendazole [MBZ, methyl 5-(benzoyl)-benzimidazole-2-carbamate] have been determined using a combination of quantum mechanics, molecular graphics, and molecular modeling techniques. Using conformational analyses and quantum mechanics, we found that the three-dimensional structure and electronic features of MBZ were consistent with those previously reported for highly active broad-spectrum benzimidazole anthelmintics and that in vivo drug efficacy against Hymenolepis diminuta depends upon the orientation of the benzoyl group at position 5 on the heterocyclic ring system, the magnitude of the molecular dipole moment, and the percentage of polar surface area. The chemotherapeutic actions of MBZ on H. diminuta in vivo were accompanied by marked changes in worm weight and chemical composition. Tapeworms recovered from rats that had received a therapeutically effective dose of MBZ 24 h earlier were significantly smaller and contained much less glycogen (as a percentage of the wet weight) than worms from untreated controls. In MBZ-treated worms, protein concentrations rose at a rate sufficient to offset the decline in glycogen concentration. Glycogen/protein ratios in MBZ-treated worms were considerably lower than the corresponding control values. Differences in the absolute amounts of glycogen between control and drug-treated worms were even more profound. Administration of a curative dose of MBZ to the rat host produced in H. diminuta another change, the onset of which coincided with the gross alterations in worm weight and chemical composition.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

The central nervous system of Grillotia erinaceus (Cestoda: Trypanorhyncha) as revealed by immunocytochemistry and neural tracing.

Immunofluorescent labeling and neural tracing techniques were employed in conjunction with confocal scanning laser microscopy to study the intact neuroanatomy of the central nervous system of the trypanorhynch tapeworm Grillotia erinaceus. Immunocytochemical labeling for the general nerve fibre marker PGP 9.5 showed a pattern of extensive labeling that paralleled findings obtained with the neural tracer DiI. In contrast, immunocytochemical labeling for 5-hydroxytryptamine (5-HT) was localised to cell bodies lying on the periphery of the ganglion, with fine immunoreactive fibres radiating out towards the bothridia. Following the retrograde transport of the fluorescent molecule DiI through axotomised nerve cords, it successfully labeled both the cerebral ganglion and associated nerve fibres within the scolex. The cerebral ganglion was shown to give rise to posterior nerve cords, an array of radial fibres that pass out to the bothridia, and to contain a centrally disposed group of cell bodies thought to be involved in efferent functions.

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↗
PubMed1992

Neuroanatomy of Cysticercus cellulosae (Cestoda) as revealed by acetylcholinesterase and nonspecific esterase histochemistry.

The nervous system of Cysticercus cellulosae, the metacestode stage of the tapeworm Taenia solium, was delineated using histochemical methods for the localization of the enzyme markers; nonspecific esterase and acetylcholinesterase. The main features of the nervous system include a pair of cerebral ganglia, a circumcerebral nerve ring, a rostellar nerve ring, and anterior and posterior nerves and their branches. The posterior nerves form a subtegumental network in the strobila and the bladder wall. A nerve network around excretory tubules could also be demonstrated, suggesting neuronal control of excretion in the metacestode. No sheath was observed around the nervous system. The morphological features described suggest "cephalization" of the nervous system in this parasite.

Acetylcholinesterase↗
PubMed1987

Augmentation of postresection mucosal hyperplasia by plerocercoid growth factor (PGF). Analog of human growth hormone.

Postresection villus hyperplasia is a major compensatory mechanism in the short-bowel patient. Substances capable of augmenting postresection mucosal hyperplasia could have therapeutic implications. Human growth hormone (hGH) and human growth hormone releasing factor (hGHRF) stimulate growth of the gastrointestinal tract; however, the diabetogenic actions of growth hormone limit its usefulness in clinical practice. Plerocercoid larvae of the tapeworm Spirometra mansonoides produce an analog of hGH void of diabetogenic side effects. We assessed effects of plerocercoid growth factor (PGF) on mucosal adaptation following 70% proximal jejunoileal resection in young rats. Mucosal weight, DNA, protein, and total sucrase activity per centimeter of bowel were increased in resected PGF-treated animals compared to resected controls. We conclude PGF augments intrinsic postresection mucosal hyperplasia following extensive intestinal resection.

Animals↗
PubMed1992

Dipylidium caninum in an infant.

The tapeworm, Dipylidium caninum, occurs worldwide in dogs and cats. It may occur rarely in children, when the infection may be unrecognised or misdiagnosed. We report such a case.

Cestode Infections↗
PubMed1996

Neuronal signal substances in asexual multiplication and development in flatworms.

1. The phenomenon of asexual multiplication is rare in the animal kingdom. It occurs, however, in all main flatworm taxa. Flatworms are characterized by an extensive versatility, ranging from the different types of asexual multiplication to the different orthogonal plans for the nervous system. The role of the nervous system in the asexual multiplication taking place in flatworms is pointed out and discussed. 2. Immunocytochemical studies of the changes in the flatworm neuroanatomy show that the nervous system, particularly the main never cords, has a central role during asexual development. 3. Antibodies to different neuronal substances yield different immunoreactivity patterns and develop according to different time schedules. Serotoninergic nervous elements seem to have a leading role. 4. Substances produced by the nervous system influence fissioning and subsequent regeneration in free-living flatworms in the following ways. (a) A function as a wound hormone has been suggested for the neuropeptide RF-amide. (b) Mitogenic effects have been shown for several biogenic amines and neuropeptides. (c) Inhibitory roles are suggested for somatostatin and melatonin in connection with cell proliferation respective fissioning. 5. Growth factors have been observed both in free-living and parasitic flatworms. 6. Cells reactive to antibodies against epidermal growth factor increase in number in parallel with increases in mitotic activity in the gull tapeworm and occur in regions with high mitotic activity. A correlation between these two phenomena is suggested.

Animals↗
PubMed2003

Neurocysticercosis--New Millennium, ancient disease and unending debate.

A spurt of cases of Neurocysticercosis (NCC) at our department reopened the debate on whether to treat or not and spurred us on to review the available literature for a viable solution. Despite the disease having been around for centuries a cogent treatment plan eludes us even as other ancient scources have been successfully engaged. Neurocysticercosis presents a peculiar problem as it is an end-stage infection, accidental in man, with a benign natural course and would have merited considerably less attention, had it not chosen to infest the brain. These unique and characteristic features are the fundamental reasons why so many different treatment strategies are continuously proffered; many or none seem to work, depending on the viewpoint. And the target organs of this otherwise unglamorous tapeworm cyst--the brain, eye and spinal cord-ensure that there is always pressure, and temptation to treat rather than let it be, even if the weight of evidence is to the contrary. An overview of the history of the disease and the most recent happenings is presented here, in which these issues are reviewed with special attention to the debate on treatment. From the facts that emerge, an attempt has been made to present a workable plan that would help practicing pediatricians in treating most encountered cases till such time we hear the last word on the issue.

Albendazole↗
PubMed1997

Isolation and characterization of five actin cDNAs from the cestode Diphyllobothrium dendriticum: a phylogenetic study of the multigene family.

Five cDNAs (pDidact2-pDidact6), representing different actin genes, were isolated from a Diphyllobothrium dendriticum cDNA library, and the DNA as well as the putative amino acid sequences were determined. The corresponding Didact2 and Didact4 genes code for peptides 376 amino acids long, with molecular weights 41,772 and 41,744 Da, respectively, while the deduced Didact3 protein is 377 amino acids long and weighs 41,912 Da. The pDidact5 and -6 cDNAs lack nucleotides corresponding to three to six amino acids at the amino-terminus. Two of the five cDNAs contain the conventional AATAAA as the putative polyadenylation signal, one has the common variant ATTAAA, whereas the hexanucleotide AATAGA is found 15 and 18 nucleotides, respectively, upstream of the poly(A) site in two of the cDNAs. Phylogenetic studies including 102 actin protein sequences revealed that there are at least four different types of cestode actins. In this study three of these types were found to be expressed in the adult D. dendriticum tapeworm. Structurally the cestode actin groupings differ from each other to an extent seen only among the metazoan actins between the vertebrate muscle and cytoplasmic isoforms. In the phylogenetic trees constructed, cestode actins were seen to map to two different regions, one on the border of the metazoan actins and the other within this group. It is, however, difficult to say whether the cestode actins branched off early in the metazoan evolution or if this position in the phylogenetic tree only reflects upon differences in evolutionary rate.

Actins↗
PubMed1997

[Osseous echinococcosis].

Hydatid disease is caused by the parasitic tapeworm Echinococcus. The larval stage of this parasite can thrive in many parts of the body, most frequently in the liver. Primary bone location is very rare, accounting for less than 2% of all hydatid lesions. We report on a case of left-sided extended pelvic infestation. The destruction of the hip joint, os pubis, large parts of the ileum and the femoral head made pelvic resection and prosthetic replacement necessary. Recurrence of a hydatid cyst 5 years later in the left groin originating from the proximal femur was treated with second femoral resection and new total hip replacement. Because of instability, the primarily inserted polyacetal pelvic replacement had to be exchanged for a custom-made device fabricated with the aid of computer-aided design (CAD) techniques. This surgical procedure was combined with chemotherapy (mebendazole). The necessity of radical resection in osseus hydatid disease is discussed.

Antinematodal Agents↗