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PubMed1983

Identification of immunogenic proteins of Dipetalonema viteae (Filarioidea) by the "Western Blotting" technique.

Sodiumdodecylsulphate (SDS)-solubilized proteins of several developmental stages of Dipetalonema viteae (adults, uterus content, microfilariae, infective larvae) were subjected to SDS-polyacrylamide gel electrophoresis and transferred onto nitrocellulose filter sheets. Their antigenicity in natural infections of Meriones unguiculatus was investigated by immuno-recognition with pooled sera of infected hosts. The antibodies were labelled by radioiodinated protein A and visualized by autoradiography. Immunorecognized protein bands were demonstrable in all stages, some of them being stage specific, others common to several or all stages. The highest number of labelled protein bands was found in extracts of adult worms, the lowest in preparations of microfilariae and infective larvae.

Animals↗
PubMed1983

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. (Nematoda: Filarioidea) from Colombian capybaras.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. is described from specimens recovered from skeletal muscle fascia of the capybara, Hydrochoerus hydrochacris, from several localities in Colombia, South America. The microfilaria, which is found in the skin of the host, is also described for the first time. The monotypic species of the subgenus Alafilaria can be distinguished from existing Dipetalonema subgenera and all filariae known to us, on the basis of numerous preanal caudal papillae in males, small size of petals on the caudal extremity of each sex, and low, bluntly-rounded lateral alae in the cuticle of adult worms of both sexes. Unusual and distinctive features of the microfilaria include conspicuous lateral cuticular alae and a caudal extremity devoid of nuclei.

Animals↗
PubMed1983

Immunocytochemical studies on several developmental stages of Dipetalonema viteae (Filarioidea).

The binding of antibodies to infective larvae (L3), eggs, uterine contents and blood microfilariae was demonstrated by light microscopy employing the peroxidase-antiperoxidase (PAP) method. Antigen-antibody reactions were located on the shell of filarial eggs as well as on the cuticle and the interior of L3 and microfilariae. Using sera from Meriones unguiculatus, Mastomys natalensis and golden hamsters infected with D. viteae obtained at 7, 14, 21 and 28 weeks p.i. it was observed that the intensity of the immunostaining on several developmental stages of the filariae decreased with increasing duration of infection. This effect was more pronounced in the case of M. unguiculatus and M. natalensis than in the case of golden hamsters. For detection of surface antigenicity the simple procedure of drying the test material on microscopic slides proved to be time saving and equally specific as compared to the embedding in Epon of the filarial stages and the successive preparation of semithin sections. However, embedded filarial stages presented more intensive immunostaining than nonembedded stages. Moreover, sections allowed to demonstrate antigen-antibody reactions on the cuticle as well as inside the body cavity of the stages.

Animals↗
PubMed1983

Simulium jenningsi Malloch (Diptera: Simuliidae): a vector of Onchocerca lienalis Stiles (Nematoda: Filarioidea) in New York.

Biting flies were collected from the umbilical areas of Onchocerca lienalis-infected cattle in New York (state) from June through September of 1980. Of the 766 flies collected, 705 were Simulium jenningsi. Microfilariae were detected in the midguts of 37 (50%) of 73 females dissected immediately after the flies had fed. The mean number of larvae per positive fly (fly with microfilariae) was 15.2. Third-stage larvae were recovered from 25 (21.9%) of 114 S jenningsi dissected 8 to 13 days after they had fed on the infected cattle; the mean number of 3rd-stage larvae per positive fly was 3.5. Dissections of flies performed on days 1 through 7 after feeding yielded various numbers of 1st and 2nd-stage larvae from the thoracic muscles. Ovarian dissections performed on 304 S jenningsi attacking cattle indicated an overall parous rate of 58%. Naturally occurring infections with filarial larvae indistinguishable from O lienalis were found in 7.3% of the parous females. Three of these flies, or 1.7% of the parous collection, harbored 3rd-stage larvae. The onset of naturally occurring filarial infections in the population of S jenningsi coincided with a peak in the parous rate in late June. Thereafter, filarial infections were generally detected when the parous rate was above 50%.

Animals↗
PubMed1980

Dipetalonema (Cercopithifilaria) kenyensis subgen. et sp. n. (Nematoda: Filarioidea) from African baboons, Papio anubis.

Dipetalonema (Cercopithifilaria) kenyensis subgen. et sp. n. is described from the subcutaneous connective tissues of Papio anubis, from Kenya, Africa. Of the six recognized subgenera of the genus Dipetalonema, Cercopithifilaria most closely resembles Loxodontofilaria and Chenofilaria in having an undividied esophagus. The appearance of the female tail and the number and arrangement of the caudal papillae in the male distinguish it from these two subgenera. The species kenyensis is distinct from all other species by its body size, its microfilaria, and the size and shape of the spicules. This is the first species of Dipetalonema to be described from an African primate.

Animals↗
PubMed1982

Complement-mediated leukocyte adherence to infective larvae of Dipetalonema viteae (Filarioidea): requirement for eosinophils or eosinophil products in effecting macrophage adherence.

The present study reports the existence of C-mediated adherence of eosinophils and/or macrophages to filarial infective larvae of Dipetalonema viteae. C3 molecules are present on the surface of the parasite, as shown by immunofluorescence studies. Samples of fNRS depleted of AP of complement by treatment with Zymosan A or of factor B by heating at 50 degrees C for 20 min fail to mediate cell adherence to the parasite. In contrast, fNRS inactivated for CP of complement by the chelating agent EGTA retains its activity in mediating cell adherence to the parasite. There is a significant consumption of factor B and AP of complement when infective larvae are incubated in fNHS. Consumption of C4 of the CP of complement is much lower in the same test. The adherence of macrophages cannot occur without the simultaneous presence of eosinophils, whereas eosinophils probably act alone and not in concert with macrophages. The eosinophil adherence is associated with degranulation. The damage is notably enhanced by replacing the spent eosinophil population with a newly obtained population. In the present test system, mast cells did not adhere to filarial larvae even when mast cell-rich populations were used, nor did they effect macrophage adherence when presented in association with the latter. When eosinophil-enriched cell populations containing less than 1% mast cells were used, cell adherence to filarial larvae still occurred, but the presence of 30% mast cells in such cell populations markedly increased both the rate and level of adherence. We suggest that a cell-mediated adherence and destruction dependent upon the activation of complement via AP, without a requirement for specific antibody, may represent a natural mechanism of parasite killing in a nonimmune host.

Animals↗
PubMed1980

Redescription of Dipetalonema (Acanthocheilonema) procyonis Price 1955 (Nematoda: Filarioidea from the raccoon.

Dipetalonema (Acanthocheilonema) procyonis Price 1955 is redescribed from specimens recovered from the subcutaneous tissues of raccoons (Procyon lotor) in Louisiana. The microfilaria, which is found in the skin of the host, is described for the first time. Dipetalonema (A.) procyonis can be distinguished from other members of the subgenus Acanthocheilonema based on the presence of four conical petals on the posterior extremity of both sexes; the females of all other previously described species possess three caudal appendages.

Animals↗
PubMed1980

Studies on Dipetalonema viteae (Filarioidea). 5. Ultrastructural aspects of the antibody-dependent cell-mediated destruction of microfilariae.

The antibody-dependent cell-mediated destruction of Dipetalonema viteae microfilariae was followed by electron microscopy both in vitro and within micropore chambers in vivo. There was a correlation between the degree of adherence (1% mf with adhered cells) and the degree of microfilarial damage. Polymorphonuclear leukocytes, predominantly neutrophils, seemed to be responsible for the destruction of microfilariae in vivo. An in vitro assay indicated that eosinophils also have a role as potent effectors against microfilariae. The first sign of microfilarial damage is the disintegration of cuticular layers. In a later stage of destruction, lysis of the hypodermis or even of the whole microfilarial tissues was observed.

Animals↗
PubMed1982

Dipetalonema (Dasypafilaria) averyi subgen. et sp. n. (Nematoda: Filarioidea) from the nine-banded armadillo, Dasypus novemcinctus in Louisiana.

A new filarial nematode, Dipetalonema (Dasypafilaria) averyi subgen. et sp. n., is described from the omentum of armadillos (Dasypus novemicinctus) for southern Louisiana. Within the genus, the large buccal cavity, the absence of a gubernaculum, the reduced number of caudal papillae, the large caudal lappets, and the sheathed microfilaria serve to distinguish the subgenus Dasypafilaria from other subgenera. The small size of D. averyi (females 5.3-9.5 mm long by 70-90 micrometers wide; males 3.8-5.5 mm long by 46-70 micrometers wide) readily distinguishes it from other species in the genus. It also is distinguished by its rounded cephalic extremity, the location of the vulva at the level of the base of the esophagus, the morphology of the spicules, and the size and configuration of the microfilaria.

Animals↗
PubMed1981

The transmission of Onchocerca tarsicola (Filarioidea: Onchocercidae) by Odagmia ornata and Prosimulium nigripes (Diptera: Simuliidae).

Onchocerca tarsicola is a subcutaneous filariid of the red deer living on the tendons of the radial-carpal and tibial-tarsal joints. Its microfilariae concentrate mainly in the external ears. The extrinsic cycle of this parasite was investigated. In a hyperendemic area wild-caught Odagmia ornata were dissected, as well as samples which had fed on a tame deer and been kept in the laboratory after the infecting blood-meal. About 3 to 5% of the flies were infected with larval stages of Onchocerca tarsicola. More than 40% of Odagmia ornata induced to feed on the ears of the deer became infected and about 30% of the flies which survived more than 18 days contained third-stage larvae. The larval development in the vector is described. Prosimulium nigripes appears to be a second natural vector of Onchocerca tarsicola. Observations concerning the potential vectors of O. flexuosa, O. tubingensis and Cutifilaria wenki living in red deer are discussed.

Animals↗
PubMed1995

Identification of voltage-sensitive calcium channels in Setaria cervi (Nematoda: Filarioidea) and their role in regulation of spontaneous motility.

Whole worm of Setaria cervi and its nerve muscle preparation exhibit rhythmical movements when suspended in modified Ringer's solution in an isolated organ bath. Deprivation of calcium from the bathing fluid results in gradual reduction in the amplitude and rate of contraction till the movements ceased completely. Similar results were obtained by adding EDTA (5 micrograms/ml) to the bath. The effect was concentration related and was evident early with higher concentration of EDTA. Acetylcholine which increases spontaneous movements of the whole worm as well as N.M. preparation failed to do so when the movements were inhibited either in calcium free solution or in the presence of EDTA. Addition of calcium channel blocker, Nifedipine to the bathing fluid also resulted in concentration related reduction of movements of the preparation of Setaria. Further, the stimulant response of Ach was also reduced by Nifedipine and this too was related to the concentration of calcium channel blocker in the bath. The evidence clearly indicates that presence of calcium is essential for the stimulant response of Ach on S. cervi, which like mammalian tissues contain calcium channels that can be blocked by specific blocking agents.

Acetylcholine↗
PubMed1995

Scanning electron microscopy of adult Wuchereria bancrofti (Nematoda: Filarioidea).

Despite the great importance of Wuchereria bancrofti in causing human lymphatic filariasis, only conventional morphological studies have been completed with adult forms of this filaria. No ultrastructural studies have been carried out, mainly due to the difficulty in obtaining viable parasites from human tissues and the lack of a suitable experimental model or in vitro cultivation. With the recent success in using ultrasound to localize adult worms in living tissues and their surgical recovery from human lymphatic vessels, we show in the present paper the first ultrastructural observations of this filarial form. The cuticle surface analyzed by scanning electron microscopy showed a transversal striated aspect with periodic annulations and many small protuberances irregularly distributed along the filaria. The adults present a specialized cephalic area, with the oral opening surrounded by a circular mouth, papillae, and amphidial opening. Other structures, for example the anal, vulvar, and cloacal opening and spicules, were also observed and are described herein.

Animals↗
PubMed1993

Immunoreactive proteins of Acanthocheilonema viteae (Nematoda: Filarioidea) adults: solubilization in various detergents.

For optimal solubilization of immunoreactive proteins of filarial parasites, adult worms of Acanthocheilonema viteae were extracted in different detergents including anionic, cationic, nonionic and zwitterionic agents under varying incubation periods. Each preparation was then analysed by SDS-PAGE and immunoblotting using pooled sera from Mastomys natalensis infected with A. viteae. Amongst the detergents used, maximum immunoreactive proteins were exposed by sodium dodecylsulphate (SDS), closely followed by sodium deoxycholate (DOC). Nevertheless, a few additional protein bands were recognized by infected sera in DOC preparations, but not in SDS, and vice versa. Most of the proteins were completely or partially dissolved within 2 hrs extraction time. It is felt that DOC may be used in place of SDS because of the strong denaturing character of the latter.

Animals↗
PubMed1993

Cryopreservation of infective larvae of Onchocerca volvulus (Filarioidea: Onchocercidae).

Infective larvae (L3) of Onchocerca volvulus were procured in Liberia, West Africa, in the natural black fly vector, Simulium yahense. A cryobiological technique was developed to preserve L3 of O. volvulus that were fully viable after thawing. Larvae were treated before cooling with 4 cryoprotective compounds. Three compounds, dimethyl sulfoxide (DMSO), glycerol, and ethylene glycol, were prepared with distilled water. The fourth compound was DMSO prepared in different concentrations with 0.25 M sucrose. The treatment with DMSO + 0.25 M sucrose cryoprotectant resulted in the highest survival of infective larvae. Five cooling rates between 0.5 C/min and 20.0 C/min were applied. The highest survival of L3 was with the cooling rate of 1.0 C/min. Two-step cooling of L3 was applied. In the first step, L3's were frozen to 5 levels from -10.0 C to -20.0 C, -30.0 C, -40.0 C, -60 C, and -80.0 C, and in the second step, larvae were transferred into liquid nitrogen at -196 C for rapid cooling and storage. The survival was the highest when larvae were cooled to approximately -40 C prior to transfer into liquid nitrogen. Slow, gradual, and rapid thawing procedures were applied. The survival was the highest in rapid warming.

Animals↗
PubMed1997

Ultrastructure of infective larvae (L3) of Onchocerca volvulus (Nematoda: Filarioidea) developed in Simulium yahense in Liberia.

Third-stage infective larvae of Onchocerca volvulus were examined to elucidate the ultrastructure and the interrelations of the stoma, esophagus, intestine, and nervous system. The alimentary canal involves a cuticularized stoma with a triradiate lumen that is continuous with a similar triradiate lumen in the muscular region of the esophagus. The lumen wall may be laterally appressed or opened into a stellate form in the glandular region. Posteriad from the esophagointestinal valve, the cylindroid lumen becomes partially occluded with microvilli formed by the evaginations of the apical membranes of the intestinal epithelium. Cross sections, through this region reveal that groups of 5 radiating epithelial cells are joined near the lumen surface by junctional complexes. The alimentary canal terminates via a rectal valve and channel supported by somatic and neural cells. The central nervous system consists of a nerve ring that surrounds the muscular region of the esophagus. Related neurons support chemoreceptors and tactoreceptors of sensilla and the extensive coelomyarian and meromyarian somatic muscles. Extensive accumulations of glycogen rosettes are present in many of the muscle and hypodermal cells.

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