Showing papers in "Journal of Helminthology in 1981"
TL;DR: Differences in biochemical composition and metabolism observed between adults produced experimentally and those obtained from naturally infected dogs, may have been as a result of their original hydatid source and/or their differing stage of development.
Abstract: A comparative biochemical study was performed on adult and cystic stages of Echinococcus granulosus . Basic quantitative differences in metabolism were apparent between the cystic forms of sheep origin from the UK and Kenya which suggest that each may represent a different geographical strain or sub-strain. The biochemistry of the human and sheep forms from Kenya was very similar, which probably reflects a certain close affinity between the two. The fact that the cattle, goat and camel forms of E. granulosus , from that country, were distinct biochemically, both from each other and from the sheep and human types, suggests the existence of an unusually complex strain picture there, and that these organisms are either noninfective or only poorly infective to man. The differences in biochemical composition and metabolism observed between adults produced experimentally and those obtained from naturally infected dogs, may have been as a result of their original hydatid source and/or their differing stage of development.
49 citations
TL;DR: A strong correlation was shown between coenurus volume and the number of scolices on the coenuru membrane, with a poor correlation between coENurus age and volume.
Abstract: Measurements were made of gravid worm lengths, scolex diameter, rostellum diameter, sucker diameter, and large and small rostellar hooks of adult Taenia hydatigena, T. multiceps, T. ovis and T. pisiformis obtained from dogs in North Wales. Values recorded agreed closely with published values. None of these characters could be used to differentiate reliably between the species except that, of the worms examined, those with large rostellar hooks greater than 228 microns were T. pisiformis and those with large hooks less than 168 microns were T. multiceps. The range of hook lengths of the different species overlapped considerably. Reliable identification required examination of mature proglottis morphology of specimens which were relaxed before fixation. Relaxed mature proglottides often showed a characteristic shape. Lengths of rostellar hooks of scolices from T. multiceps coenuri followed the same frequency distribution as adult worm books. A strong correlation was shown between coenurus volume and the number of scolices on the coenurus membrane, with a poor correlation between coenurus age and volume.
40 citations
25 citations
TL;DR: The histological features of the plerocercoids, their relation to the host, adult pattern and susceptibility of hosts allowed us to determine the presence of Diphyllobothrium dendriticum (Nitzch) for the first time in South America in the lacustrine region of southern Chile.
Abstract: Experimental infections were established with Diphyllobothrium sp. plerocercoids obtained from Salmo gairdneri, a fish introduced at the beginning of the 1900s in the lake region of Chile. These permitted us to obtain adult parasites in Larus dominicanus and Canis familiaris. The histological features of the plerocercoids, their relation to the host, adult pattern and susceptibility of hosts allowed us to determine the presence of Diphyllobothrium dendriticum (Nitzch) for the first time in South America in the lacustrine region of southern Chile. It is believed that this cestode was introduced to this ecosystem by infected persons travelling from North America of Europe or, alternatively, brought by migratory birds, e.g., Sterna hirundo, S. paradisea or Larus pipixcan on their winter visits to South America.
24 citations
TL;DR: A substantial level of resistance to a heterologous challenge with Fasciola hepatica was demonstrated in sheep harbouring primary non-patent and newly patent Schistosoma bovis infections, the liver-fluke burdens being reduced by 70% and 93%, respectively, in these groups compared with that of the challenge control group.
Abstract: A substantial level of resistance to a lictcrologous challenge with Fasciola hepatica was demonstrated insheep harbouring primary non-patent (two- to three-week-old) and newly patent (seven- to cight-wcck-old)Schistosoma hovis infections, the liver-fluke burdens being reduced by 70% and 93%, respectively, ( p< 0·01) inthese groups compared with that of the challenge control group.
24 citations
TL;DR: A substantial resistance to a heterologous challenge with Fasciola hepatica was demonstrated in calves harbouring primary patent Schistosoma bovis infections of an age of 10 weeks at challenge, the mean worm burden being reduced by 29.9% in calves primarily infected with S. Bovis.
Abstract: A substantial resistance to a heterologous challenge with Fasciola hepatica was demonstrated in calves harbouring primary patent Schistosoma bovis infections of an age of 10 weeks at challenge, the mean worm burden being reduced by 29·9% (p < 0025) in calves primarily infected with S. bovis as compared with that of the challenge control group. The heterologous resistance was also evidenced by less pronounced liver tissue damage and lower serum gammaglutamyl-transpeptidase values in the S. boms-infected animals compared with the challenge control group.
24 citations
TL;DR: The rate of uptake of H3 tyrosine by unisexual females in vitro was accelerated by 22% when male worm extract was added to the culture medium and Pairing of un bisexual females with mature male worms in vitro resulted in a similar acceleration of H2Tyrosine uptake.
Abstract: The rate of uptake of H3 tyrosine by unisexual females in vitro was accelerated by 22% when male worm extract was added to the culture medium. Pairing of unisexual females with mature male worms in vitro resulted in a similar acceleration of H3 tyrosine uptake. As tyrosine is avidly taken up by the vitelline gland for the formation of egg shell protein the change in the rate of H3 tyrosine uptake can be employed as a sensitive quantitative criterion for assessing its development following stimulation.
22 citations
TL;DR: The first report of heterophyid infection in man and carnivores in Iran is reported, which revealed that 14.2% of jackals, 33.3% of foxes and 2.5% of dogs were infected with heterophyids.
Abstract: Trematodes of the family I Ictcrophyidac in man and carnivores were studied in Khuzcstan, south-west Iran.Hight hundred and eleven stool samples from a population of 3400 in 13 villages in a swampy area located incentral Khuzcstan were examined by the formalin-ether concentration technique. The following helminths were found: Ascaris lumbricoides 7%, Trichostronayius spp. 53%, hookworms 4%, Trichuris trichiura 5%, Hywenolepis nana 12% and hetcrophyid spp. 8%. Post-mortem examination of carnivores revealed that 14·2% of jackals, 33·3% of foxes and 2·5% of dogs were infected with hctcrophyids, namely Metagonimus yokogawai, Heterophyes heterophyes and H. katsuradai. The freshwater snails Melanoides and Melanopsis spp. and brackish water fishes ltarhus spp. and Mugil spp. were thought to be the intermediate hosts of these flukes in this area. This is the first report of hctcrophyid infection in man and carnivores in Iran.
22 citations
TL;DR: The chemotherapeutic responses of three test nematodes, Nippostrongylus brasiliensis, Nematospiroides dubius and Ancylostoma ceylanicum to standard anti hookworm drugs were assessed in order to select a suitable host-parasite system for the primary screening of potential antihookworm compounds.
Abstract: The chemotherapeutic responses of three test nematodes, Nippostrongylus brasilietxsis, Nematospiroidesdubius and Ancylostoma ceylanicum to standard antihookworm drugs were assessed in order to select asuitable host-parasite system for the primary screening of potential antihookworm compounds. N. dubiusbehaved inconsistently and, with some infections, required more drug to achieve 100% clearance. Nippostrongylus brasiliensis was found to be sensitive to thiabendazole, tetramisole and levamisole but the broad spectrum anthclmintic mebendazole was ineffective. A. ceylanicum was very sensitive to mebendazole, sensitive to tetramisole and levamisole and refractory to thiabendazole. In vitro , none of the compounds had any lethal effect against any of the nematodes, except mebendazole against A. ceylanicum . A. ceylanicum does occur in man and its chemotherapeutic reactions are similar to those of target hookworm infections of economic importance. As such, although not equally sensitive to standard anthelmintics, it is recommended for routine primary screening.
21 citations
TL;DR: Prosimulium nigripes appears to be a second natural vector of Onchocerca tarsicola and Observations concerning the potential vectors of O. flexuosa, O. tubingensis and Cutifilaria wenki living in red deer are discussed.
Abstract: Onchocerca tarsicola is a subcutaneous filariid of the red deer living on the tendons of the radial-carpal and tibial-tarsal joints. Its micronfilariae 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. Jlexuosa, O. tubingensis and Cutifilaria wenki living in red deer are discussed.
19 citations
TL;DR: The effect of oxyclozanide, hexachlorophene, nitroxynil, rafoxanide and diamphenethide on malate dehydrogenase activity of homogenates of Fasciola gigantica, Fasciolopsis buski and Paramphistomum explanatum was investigated.
Abstract: The effect of oxyclozanide, hexachlorophene, nitroxynil, rafoxanide and diamphenethide on malate dehydrogenase activity of homogenates of Fasciola gigantica, Fasciolopsis buski and Paramphistomum explanatum was investigated. The ratio of oxaloacetate reduction to malate oxidation in homogenates of Fasciola gigantica, Fasciolopsis buski and P. explanatum was 4·5:1, 3·6:1 and 5·2:1 respectively. Oxyclozanide and rafoxanide at 10−3 M inhibited enzyme activity by 100% in homogenates from all three species while hexachlorophene at 10−3M also caused 100% inhibition in homogenates from Fasciola gigantica and P. explanatum but only 65% of malate oxidation in Fasciolopsis buski homogenates. Nitroxynil at 10−3M produced 60% inhibition in F. buski homogenates yet had little effect at this concentration on preparations from the other species. Little inhibition was seen with diamphenethide, even at high concentrations. Rapid death of Fasicola gigantica and P. explanatum resulted in vitro when 10−3M oxyclozanide, hexachlorophene, nitroxynil or rafoxanide, were added to the incubation medium. Fasciolopsis buski was killed by 10−3M oxyclozanide but at this concentration the remaining compounds only caused reduced activity. Assay of malate dehydrogenase following drug treatment in vitro failed to show any appreciable reduction in enzyme activity in Fasciola gigantica and P. explanatum but oxyclozanide and hexachlorophene produced inhibition in Fasciolopsis buski. The mode of action of these compounds is discussed.
TL;DR: All the natural hosts of Onchocerca parasites are large animals and there is an urgent need to develop a small animal model for onchoccrciasis, preferably one that employs a strain of inbred host.
Abstract: All the natural hosts of Onchocerca parasites are large animals (MULLI-R, 1979) andthere is, therefore an urgent need to develop a small animal model for onchoccrciasis,preferably one that employs a strain of inbred host. Rodents have been usedsuccessfully as experimental hosts for the microfilariac of O. guiturosa (sec NELSON et al. 1966), O. cervicalis (see RAbalais, 1974), O. armilluta (see EL Bihari & Hussein, 1975) and O. ijibsoni (see Beveridge et al. , 1980) but there have been few publishedattempts to infect these hosts with infective-stage larvae.
TL;DR: The infection pattern of Habronema spp.
Abstract: Six to nine horses per month (total of 94 in a year) were examined for stomach worms in the Settat region of Morocco. All the animals were infected by at least one helminth species. Habronema muscae occurred in 95–8%, H. majits in 75.6% and Trichostrongylus axeiin 80.9% of horses. Polyparasitism was observed in 93.6% of horses. Both for Habronema spp. and T. axei the peak worm burden was observed in November and minimum in June. The infection pattern Habronema spp. was directly related to the period of activity of fly vectors.
TL;DR: It has not been possible to identify the physiological components on the circadian rhythm of the human body which entrain the cycle of these microfilariae.
Abstract: 1. Investigations were made of the effect of various procedures in raising or lowering the microfilaria count of Pacific type Wuchereria bancrofti in the peripheral blood. 2. Raising the body temperature in the early morning was followed by a moderate fall in the counts. Breathing increased oxygen, or reduced oxygen (hypoxia) or increased carbon dioxide, or the ingestion of sodium bicarbonate produced no consistent and significant change in the count. Ingestion of glucose (in one volunteer) was followed by a small rise in the count. Muscular exercise was followed by a fall in the count, which is interpreted as probably being a response to a lower concentration of oxygen in the venous blood returning to the lung. 3. It has not been possible to identify the physiological components on the circadian rhythm of the human body which entrain the cycle of these microfilariae. Attempts to obtain evidence incriminating the stimuli described above have been unsuccessful.
TL;DR: The utility of human filarial serum immunoglobulin (FSI) in detecting circulating antigen in filarial sera was studied by counter immunoelectrophoresis (CIEP) and the indirect haemagglutination test (IHAT).
Abstract: The utility of human filarial serum immunoglobulin (FSI) in detecting circulating antigen in filarial sera was studied by counter immunoelectrophoresis (CIEP) and the indirect haemagglutination test (IHAT). CIEP was found to be better than IHAT. 23 out of 30 sera from persons with microfilaeremia and one of 30 clinical cases of filariasis, but none of the normal sera or sera from those with helminths other than filariae, showed the presence of circulating filarial antigen in CIEP. FSI was fractionated by DEAE- Sephadex A-50 column chromatography and the antibody active in CIEP was found to be IgG in nature.
TL;DR: The major organs of jirds with prepatent and chronic patent infections of Brugia pahangi were studied by standard histological, electron microscopical and fluorescent antibody techniques and changes observed and not previously described in detail or in large numbers of animals are reported.
Abstract: The major organs, other than lymphatics, of jirds (Meriones unguiculatus) with prepatent and chronic patent infections of Brugia pahangi were studied by standard histological, electron microscopical and fluorescent antibody techniques. Changes observed and not previously described in detail or in large numbers of animals are reported. Multifocal non-suppurative interstitial nephritis was observed in 4% on animals with patent infections of 163 days duration and in 69% of animals with patent infections of 274 days duration. Glomerular changes were not observed in kidneys of any animals infected with B. pahangi. The occurrence of large granulomata composed of lymphocytes, macrophages, eosinophils and giant cells in the liver and smaller granulomata in the spleen correlated with patency of infections but microfilariae or worm antigens were not observed in these areas. Amyloid deposits were demonstrated in the spleen of 4% of animals with patent infections of 163 days duration and in 38% of animals with patent infections of 274 days duration but were not seen in uninfected animals of the same age or animals receiving only challenge inoculations of 28 days duration.
TL;DR: Sera of animal species other than dog are chemotactically active for infective larvae of Ancyclostoma caninum, and those sera were also found to contain such a factor(s), although the larvae were attracted significantly better by dog serum.
Abstract: Experiments were carried out to investigate if sera of animal species other than dog are chemotactically active for infective larvae of Ancyclostoma caninum. those sera were also found to contain such a factor(s), although the larvae were attracted significantly better by dog serum. How this chemotaxis might be applied to the in vivo situation, when infective A. caninum larvae penetrate the skin of dogs, is discussed.
TL;DR: The critical-point-dried specimens of Gastrothylax crumenifer and Paramphistomum epiclitum, both recovered from the rumen of sheep, were studied by scanning electron microscopy at magnifications ranging from 10 to 10,000x to reveal the structural differences of the tegument between the two species.
Abstract: The critical-point-dried specimens of Gastrothylax crumenifer (Creplin, 1847) Poirier, 1883 and Paramphistomum epiclitum Fischoeder, 1904, both recovered from the rumen of sheep, were studied by scanning electron microscopy at magnifications ranging from 10 to 10,000 x to reveal the structural differences of the tegument between the two species. In G. crumenifer , both dorsal and ventral surfaces have tubercle-like tegumental elevations, devoid of spines. A row of prominent, regularly arranged, button-like protuberances encircle the rim of mouth. It is suggested that these are sensory in nature. The lining of the buccal tube also bears papillae, some of which appear balloon-like. The tegument near the outer acetabular rim is thrown into prominent ridges bearing groups of six to eight small papilla-like elevations. Towards the interior of the acetabular cavity this pattern merges into one with stout, finger-like projections with groups of papillae at their blunt tips. From their structure, these projections appear to aid strong anchorage to the host's surface and the papillae to be secretory. P. epiclitum has a similar tuberculated pattern on the dorsal and ventral surfaces. In the oral region, the tegument has some irregular, patch-like elevated areas. The acetabular surface is thrown into a pattern of deep folds and craters.
TL;DR: A combination of indirect haemagglutination and Ouchterlony's double diffusion test could be useful for diagnosing hydatidosis in camels and probably other animals.
Abstract: Sera from 36 slaughtered camels with proven hydatid disease, from 46 camels found to be free of hydatidosis at post-mortem meat inspection, and from 26 animals with confirmed caprine heartwater, bovine trypanosomiasis and cysticercosis were examined. The indirect haemagglutination was found to be the most sensitive but least specific of the three tests. Ouchterlony's double diffusion (DD) test was specific and fairly sensitive. Although the countercurrent immunoelectrophoresis was as specific as DD, it was the least sensitive of the three serological tests. All three serological tests were always positive in camels with hydatid cyst infection affecting both the liver and the lung. A combination of indirect haemagglutination and Ouchterlony's double diffusion tests could be useful for diagnosing hydatidosis in camels and probably other animals.
TL;DR: The life span and the pathogenicity of amphistomes developing from Cercariae indicae XXVI (Paramphistomum epicilitum) were considerably reduced when the metacercariaes were gamma-irradiated at 2 krad or 3 krad.
Abstract: The life span and the pathogenicity of amphistomes developing from Cercariae indicae XXVI (Paramphistomum epicilitum) were considerably reduced when the metacercariae were gamma-irradiated at 2 krad or 3 krad. The higher irradiation dose resulted in the complete absence of the flukes in infected animals. Single vaccination of lambs and kids with 3000 metacercariae irradiated at 2 krad or 3 krad stimulated a significant degree of resistance against challenge with 5000 non-irradiated metacercariae. The resistance was more pronounced in the group vaccinated with metacercariae irradiated at 3 krad.
TL;DR: A survey revealed that Onchocerca tarsicola Bain & Schulz-Key, 1974 is a widespread parasite among reindeer in northern Finland and was highest in old animals whereas the parasites were rare in yearlings.
Abstract: A survey revealed that Onchocerca tarsicola Bain & Schulz-Key, 1974 is a widespread parasite among reindeer in northern Finland. Of 407 animals studied from 12 reindeer herds, 124 (30.5%) were infected. There was a marked difference in infection levels between different reindeer herds and the frequency as well as the intensity of infection was highest in old animals whereas the parasites were rare in yearlings.
TL;DR: Experiments showed that metaecrcariae, introduced into the intestine of tench, can excyst within one hour and cysts in contact with tench bile opened within 15 seconds, which could be modified by the presence of other helminth species.
Abstract: The natural infection of tench by Asymphylodora tincae in a lake was studied during one summer season. The incidence of infection was 57%, the mean intensity about 50. The distribution of the digencans along the host's intestine showed a maximum in the second half; this could be modified by the presence of other helminth species. Tench caught in early spring and kept in the laboratory retained their natural infection throughout the summer. Starvation of hosts during two months caused disappearance of the infection. Experiments showed that metaecrcariae, introduced into the intestine of tench, can excyst within one hour. In vitro , cysts in contact with tench bile opened within 15 seconds. Bile of several other cyprinid fisli species caused excystment within 60 seconds. Asymphylodora eggs appeared in tench faeces 7 to 10 days after infection. Progenetic specimens of A. tincae probably disintegrate in the intestine of the tench and their eggs arc passed out with the faeces.
TL;DR: A comparative study of a simplified radioimmunoassay technique with the indirect haemagglutination test in the diagnosis of 72 patients with hydatid disease indicated the greater sensitivity of the former, while the adoption of RIA as an easier method is recommended.
Abstract: A. A comparative study of a simplified radioimmunoassay (RIA) technique with the indirect haemagglutination (IHA) test in the diagnosis of 72 patients with hydatid disease indicated the greater sensitivity of the former. Both methods had an equal specificity in 60 control patients. RIA will serve as a useful addition to tests already available in hydatid serology. B. A comparison of the (RIA) technique with fluorescent antibody test (FAT) in the diagnosis of 33 patients with early, active trichinosis and 30 healthy controls indicated an equal sensitivity and specificity of both methods. The adoption of RIA as an easier method is recommended. This study of a simplified radioimmunoassay technique for the diagnosis of hydatid disease and trichinosis in man is presented in two sections.
TL;DR: Cercariae of Schistosoma bovis, S. intercalatum and S. haematobium were radiolabelled by individual exposure of their respective host snails to 75Se-methionine in 1 ml water and detectable levels of radioactivity incorporation were obtained with all three species.
Abstract: Cercariae of Schistosoma bovis, S. intercalatum and S. haematobium were radiolabelled by individual exposure of their respective host snails to 75 Se-methionine in 1 ml water for a period of 20 hours. Maximum cercaria-bound radioactivity was obtained four to seven days after labelling of snails, but detectable levels of radioactivity incorporation were obtained with all three species for a period of 32 days. The radiolabelling procedure did not interfere with the production of cercariae or with the biological characteristics of the labelled larvae. The described research opens the way for the application of various radioisotope tracer systems in studies on host-parasite relationships between cercariae and schistosomula of terminal-spined species of schistosomes and the final host.
TL;DR: The susceptibility of rats to Hymenolepis nana and the chemotherapeutic response of anti-cestode drugs was studied during egg-inducted and cysticercoid-induced infections and differences have been discussed on the basis of immunity engendered in the definitive host by the developing larvae.
Abstract: The susceptibility of rats to Hymenolepis nana (Cestoda) and the chemotherapeutic response of anti-cestode drugs was studied during egg-inducted and cysticercoid-induced infections. In cysticercoid-induced infection, the percentage of infected animals and the number of mature worms were significantly more than in egg-induced infection. The former mode of transmission required more drug to clear the parasites. These differences have been discussed on the basis of immunity engendered in the definitive host by the developing larvae.
TL;DR: In this paper, the chemical composition of Mehlis' gland secretion in Ceylonocotyle scoliocoelium was studied and it was found to be lipoproteinous in nature, containing several hydrolytic and oxidative enzymes.
Abstract: Histochemical techniques were used to study the chemical composition of Mehlis’ gland secretion in Ceylonocotyle scoliocoelium. The results suggest the secretion to be lipoproteinous in nature, containing several hydrolytic and oxidative enzymes. In tests for nine hydrolytic enzymes only seven were detected in relation to gland cells, ihe two enzymes not showing any reactivity being glucose-6-phosphatase and 5-Nucleotidase. Alkaline phosphatase and ATPase have been associated with the permeability and transport of precursors of synthetic material from the surrounding parenchyma and with eliminating the waste products from the gland: ACPase in (i) generating a favourable milieu in the gland for the synthesis of secretory material and (ii) in regulating secretion and its over production; TPPase in elaborating the secretion, esterases in the metabolism of the gland. Intense SDH and MAO activities were related to high synthetic activity of the gland cells. Phenol oxidase—a key enzyme involved in tanning was absent.