bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity of quinfamide against natural infections of Entamoeba criceti in hamsters: a new potent agent for intestinal amoebiasis
Authors: Slighter R. G. , Yarinsky A. , Drobeck H. P. , Bailey D. M. 
Published: June 2009

SUMMARYA novel tetrahydroquinolinyl ester, quinfamide, administered orally in multiple doses for 3 days had an ED50, of 0·25 mg/kg/day (total dose 0·75 mg/kg) for eradicating Entamoeba criceti in hamsters in several tests. It was significantly more active by direct comparison than 3 commercially available amoebicides and at least as active as 2 other esters of the parent compound, 1-(dichloroacetyl)-1,2,3,4-tetrahydro-6-quinonnol. After administration of a single dose, ED50, calculations for quinfamide averaged 0·9 mg/kg. Quinfamide was considerably more active than the other tetrahydroquinolinols, diloxanide furoate and teclozan, and it was approximately 1·5 times more active than etofamide; a statistical significance between the latter 2 drugs could be demonstrated in one of 4 tests. Administered prophylactically, quinfamide was shown to protect hamsters from re-infection with E. criceti. It also inhibited propagation of E. histolytica in vitro at a concentration of 20 /tg/ml. No adverse effects were noted in rodents after a single dose as high as 10 g/kg. Daily administration to monkeys of doses up to 500 mg/kg for as long as 37 days produced no pharmacological aberrations during or after medication; haematological studies and urine analyses were normal and no gross or microscopical tissue changes attributable to quinfamide were observed. No toxicity was revealed following acute (2 g/kg) and chronic (500 mg/kg/day × 31 days) administration of the drug to dogs and rats, respectively.
Fine structure of the spores of Minchinia chitonis (Lankester, 1885) Labbé, 1896 (Sporozoa: Haplosporida), a parasite of the chiton, Lepidochitona cinereus
Authors: Ball S. J. 
Published: June 2009

SUMMARYA morphological study of the fine structure of the spores of Minchinia chitonis, a haplosporidian parasite of the chiton, Lepidochitona cinereus, is described. The spores contained a single nucleus, mitochondria, haplosporosomes, smooth endoplasmic reticulum, ribosomes and a large spherule (presumed Golgi apparatus). The spore wall was discontinuous at the spherule end, forming an opening covered by a lid which rested on a circumscribed flange. The flange of the spore wall and the lid were continuous in only one area which served as a hinge. The entire spore was encapsulated by epispore cytoplasm bounded by a strengthened membrane and extended to form 2 long projections, one at either end.
Membrane transport of aromatic amino acids by Hymenolepis diminuta (Cestoda)
Authors: Pappas P. W. , Gamble H. R. 
Published: June 2009

SUMMARYAromatic amino acids (phenylalanine, tryptophan and tyrosine) are absorbed by Hymenolepis diminuta through a combination of mediated (non-Na+-sensitive) transport and diffusion. All 3 amino acids are accumulated against an apparent concentration difference during a 30-min incubation of tapeworms in 0·1 mM 3H-labelled amino acid. Inhibitor studies demonstrate that phenylalanine, tryptophan and tyrosine are mutually competitive inhibitors of the uptake of each other, and the uptake of these amino acids is inhibited by aliphatic amino acids but not by basic or dicarboxylic amino acids. The D- and L-isomers of aromatic amino acids are equally effective in inhibiting aromatic amino acid uptake. The data indicate that at least 3 amino acid transport loci are involved in aromatic amino acid transport by H. diminuta.
Detection of cholinesterase in the nervous system of the oncomiracidium of a monogenean,Pricea multaeChauhan, 1945
Authors: Venkatanarsaiah J. 
Published: June 2009

SUMMARYCholinesterase activity has been demonstrated histochemically in the nervous system, tegumental and sub-tegumental musculature of the haptor and in the pharyngeal bulb of the oncomiracidium ofPricea multae. The presence of cholinesterase in the nervous system is attributed to neurotransmission and its presence in the tegumental and sub-tegumental musculature of the haptor and pharyngeal bulb is discussed. The nervous system of the oncomiracidium with respect to cholinesterase activity is described and is compared with the nervous system of the oncomiracidium ofProtopolystoma xenopodis.
Rat-dietary fructose and the intestinal distribution and growth of Moniliformis (Acanthocephala)
Authors: Crompton D. W. T. , Keymer Anne , Singhvi A. , Nesheim M. C. 
Published: June 2009

SUMMARYThe numbers, distribution in the small intestine, sexual development and growth (dry weight) of 5-week-old Moniliformis dubius (Acanthocephala) were investigated experimentally in adult, female CFHB rats fed on theoretically isoenergetic diets containing known amounts of fructose in combination with either maize-oil fatty acids or maize oil and two concentrations of casein. There was no obvious development of M. dubius when there was no fructose in the host's diet. In contrast, estimated consumption by the host of as little as about 2 g of fructose during the 5-week infection period was accompanied by marked sexual dimorphism and weight gain in most of the M. dubius present. The dry weights of M. dubius of both sexes were positively correlated with fructose concentrations ranging from 0 to 2·5 % (w/w) in the diets containing fatty acids. Significant, but not substantial, increases in M. dubius dry weight were observed as the dietary fructose concentration was raised to 12 % (w/w). Similar trends were observed when the fructose was offered to the infected rats with maize oil, but in general, fructose added to the fatty-acid based diets supported most M. dubius growth. Differences in the distribution pattern of the worms in rats fed on the fatty-acid or maize-oil based diets were observed and their possible significance is discussed.
Attempts to induce protective immunity in hamsters against infection by a liver fluke of man (Opisthorchis viverrini)
Authors: Sirisinha S. , Tuti S. , Tawatsin A. , Vichasri S. , Upatham E. S. , Bunnag D. 
Published: June 2009

SUMMARYThe development of acquired resistance in opisthorchiasis was studied in hamsters experimentally infected with Opisthorchis viverrini. The induction of protective immunity was attempted by first exposing adult female golden Syrian hamsters to 1,2 or 3 doses of infective metacercariae obtained from naturally infected cyprinoid fishes and then reinfecting them with 80 metacercariae. In other experiments, animals that were infected with 50 metacercariae were treated with praziquantel prior to being rechallenged in order to eliminate the flukes that had developed from the first infection. The effect of long-term chronic infections was also studied. Faecal egg counts were determined at weekly intervals from 4–5 weeks onwards. The animals were killed 2–3 months after the last infection for worm recovery, and terminal faecal egg output/g faeces/worm was calculated. The data showed that prior infection of animals with O. viverrini did not induce significant protective immunity against reinfection by the same parasite. Lack of protection was also noted in animals reinfected several times with small doses of metacercariae. However, under certain circumstances, prior infection could result in a significant reduction in the faecal egg output due to subsequent infection.
Serological differentiation of the potato-cyst nematodes Globodera pallida and G. rostochiensis: partial purification of species-specific proteins
Authors: Schots A. , Bakker J. , Gommers F. J. , Bouwman-Smits L. , Egberts E. 
Published: June 2009

SUMMARYTwo major groups of heat-stable proteins have been purified by heat denaturation from homogenates of eggs of the potato-cyst nematodes Globodera rostochiensis and G. pallida. SDS-polyacrylamide gel electrophoresis of protein homogenates from 6 G. rostochiensis populations and 7 G. pallida populations revealed 2 bands specific for G. rostochiensis and 3 bands specific for G. pallida. Two-dimensional electrophoresis showed that the 2 bands specific for G. rostochiensis consisted of 2 polypeptides differing slightly in isoelectric point, as did one of the bands specific for G. pallida. Conventional antisera made against protein homogenates of either Globodera species showed a complete cross-reaction with the species-specific proteins. The perspectives of the differences in protein composition between G. rostochiensis and G. pallida, established in this study, for a quantitative differentiation of mixed field populations of the two Globodera species, involving monoclonal antibodies, are discussed.
Variation in class-specific humoral immune responses of different mouse strains to microfilariae ofDipetalonema viteae
Authors: Almond N. M. , Worms M. J. , Harnett W. , Parkhouse R. M. E. 
Published: June 2009

SUMMARYThe class-specific antibody responses of 3 strains of mice (C57/Bl10, BALB/C and CBA/N) known to vary in their ability to control the microfilaraemia which follows the subcutaneous transplantation of adult femaleDipetalonema viteaehas been investigated. The 3 mouse strains showed significant variation (a) in total levels of immunoglobulins and (b) in ability to recognize individual radio-isotope-labelled antigens as measured by coprecipitation. Within each mouse strain it was noted that antigens could vary with respect to the nature of the isotype of the antibody response which they elicited. Furthermore, by comparing results obtained from class-specific coprecipitation with surface ELISA it was found that a similar variation between responses to individual epitopes was also likely. No differences were observed in the humoral response of the 3 mouse strains which could explain the known resistance of the C57/B110 strain; reasons for this are discussed.
Interspecific characterization of several taeniid cestodes by isoenzyme analysis using isoelectric focusing in agarose
Authors: Allsopp B. A. , Jones A. , Allsopp M. T. E. P. , Newton S. D. , Macpherson C. N. L. 
Published: June 2009

SUMMARYTaenia cestodes were obtained from 5 different definitive host species in Kenya and 175 different samples were examined by classical morphological methods and by isoenzyme analysis using isoelectric focusing in agarose. Gels were stained for 17 different enzymes and 3 of these were used in the construction of isoenzyme profiles. The samples fell into 25 zymodemes, and no zymodeme contained more than 1 species of Taenia, indicating that isoenzyme analysis can reliably be used for the identification of species of this genus.
Factors affecting the establishment of the caecal threadwormTrichostrongylus tenuisin red grouse (Lagopus lagopus scoticus)
Authors: Shaw J. L. , Moss R. 
Published: June 2009

SummaryThe resistance of captive reared red grouse toTrichostrongylus tenuiswas measured as the proportion of ingested infective 3rd-stage larvae which failed to develop to adult worms. Individual grouse showed wide, repeatable variations in resistance. Seasonal variations may also have occurred. Red grouse acquired little or no effective immunity to reinfection after challenge with a single dose of infective larvae. In trickle-dosed grouse, however, adult worms weakly inhibited the establishment of incoming larvae in an intensity-dependent fashion. Despite this, the proportion of larvae established in trickle infections was similar to that in single-dose challenges.
Properties of phenol oxidase inFasciola gigantica
Authors: Nellaiappan K. , Devasundari A. Fatima , Dhandayuthapani S. 
Published: June 2009

SummaryPhenol oxidase ofFasciola giganticaexists both as the soluble form as well as the membrane-bound form. The membrane-bound enzyme is considered to be a tyrosinase type because it is capable of oxidizing mono- and diphenol and is inefficient in oxidizing paraphenols. The soluble enzyme is a laccase type showing more affinity to various diphenols and paraphenols. Membrane-bound enzyme exists as isoenzymes, showing 3 fractions, of which the slow-moving fraction is capable of oxidizing both 4-methyl catechol and catechol, whereas the two remaining fractions are specific to 4-methyl catechol only. Soluble enzyme exists as a single homogeneous form showing affinity to both mono- and diphenols. Inhibition of the enzyme by potassium iodide and mercuric chloride indicates the active tyrosyl and SH groups of the enzyme. Inhibition of the enzyme by sodium diethyl dithiocarbamate and phenyl thiourea indicates that copper is the prosthetic group of the enzyme.
Repair ofHymenolepis diminutaafter complement-mediated damage
Authors: Andreassen J. , Hoole D. 
Published: June 2009

SummarySeven and 56-day-oldHymenolepis diminutawere exposed to complement by incubation in 50% normal rat serum (NRS) in modified Hanks' saline. Ultrastructural studies revealed that the scolex/neck region remained relatively intact whilst in the strobila region microthrix denudation and loss of distal cytoplasm were observed. When complement-mediated damaged worms were incubated in vitro in 50% heat-inactivated normal rat serum (hiNRS) plus M199 or implanted into the duodenum of NMRI mice repair occurred, although destrobilated parasites were only foundin vivo. The regions undergoing repair contained tegumental protrusions, vesicles, large electron-lucent areas and large quantities of lipid. Microtriches were formed parallel to the parasite surface and were raised into a perpendicular position. It is suggested that the regenerative process exhibited after complement-mediated damage does not mimic totally the embryological development of the surface layer.
Cloning of a repetitive DNA from the rickettsia-like organisms of tsetse flies (Glossina spp.)
Authors: Welburn S. C. , Gibson W. C. 
Published: June 2009

SummaryThree DNA fragments from the genome of the rickettsia-like organism (RLO) symbiotic in tsetse flies (Glossina spp.) have been cloned. One of these fragments represents a family of highly conserved repeats, which occurs in RLO from all species of tsetse examined and has been amplified in the original RLO culture from which the DNA is cloned. This fragment serves as a highly sensitive and specific probe for the detection of RLO in tsetse midguts. As few as 30 organisms were unequivocally identified by dot blot hybridization of homogenized midgut preparations. Since the presence of RLO within tsetse midguts is associated with susceptibility to trypanosome infection, this technique provides a rapid and reliable method of assessing the potential susceptibility of a tsetse population to Trypanosoma brucei s.l. and T. congolense infections.
Strongyloides ratti: studies of cutaneous reactions elicited in naive and sensitized rats and of changes in surface antigenicity of skin-penetrating larvae
Authors: McHugh T.D. , Jenkins T. , McLaren Diane J. 
Published: June 2009

SummaryThis study provides the first quantitative assessment of the cutaneous reaction elicited in naive and sensitized rats by invading larvae of Strongyloides ratti. Parasites were identified in skin samples harvested from both naive and sensitized rats between 0·5 and 8 h following percutaneous infection, but were no longer visible at the site of invasion at 24 h. Mast cells, neutrophils, eosinophils and mononuclear cells recruited into the dermis in response to invading larvae were recorded and quantified. Cellular infiltrates were observed as early as 1 h post-invasion in naive/challenged skin, where total cell numbers were up to 3 times greater than in naive control tissue. Peak numbers of all cell types were recorded from 3 to 8 h in both naive/challenged and sensitized/challenged hosts. Interestingly, the reaction in sensitized/challenged rats was neither enhanced nor accelerated, a feature perhaps attributable to lack of recognition of parasite antigens by the host. This possibility was investigated by immunofluorescent labelling, which clearly demonstrated changes in the surface antigen profile of the parasite following penetration of the host skin both in vitro and in vivo. It is proposed that these changes in surface antigenicity constitute an evasive stratagem used by the parasite to deter the host from mounting a potentially lethal inflammatory response.
Echinococcus granulosus: a comparison of free amino acid concentration in hydatid fluid from primary and secondary cysts and host plasma
Authors: Hurd Hilary 
Published: June 2009

SummaryA total of 28 components were detected in the free amino acid (FAA) pool of hydatid fluid from primary and secondary equine cysts, secondary ovine cysts and host plasma. Examination of data from equine cysts revealed that the majority of FAAs were present in significantly greater concentrations in secondary cysts, glycine being over 30 times more concentrated. Values for total carbohydrates and glucose did not, however, differ significantly and total protein content was greater in primary cysts. Comparison of the (FAA) pool of secondary equine and ovine cysts revealed strain variation. It was demonstrated that most FAAs were more concentrated in hydatid fluid than in the corresponding host plasma, many concentration ratios exceeding 10. The possible contribution that mediated amino acid transport across the cyst wall and parasite amino acid metabolism makes to the composition of the FAA pool was discussed. No significant plasma aminoacidaemia was associated with infection.
Covariance in parasite burdens: the effect of predisposition to infection
Authors: McCallum H. I. 
Published: June 2009

SummaryRecently the phenomenon of predisposition to helminth infection has been reported in a number of studies: those individuals which are heavily infected before treatment with an anthelmintic tend also to acquire heavy parasite burdens following a period of reinfection. This correlation between parasite burdens in initial and reinfections is generated by differences between hosts in their exposure to infective stages and in their susceptibility to infection. Inter-host differences in these factors also generate the aggregated or over-dispersed parasite distributions that are usually observed. This paper uses probability theory to predict the correlation between initial and reinfection parasite burdens assuming that those inter-host differences which generate over-dispersion remain constant for a given individual between initial and reinfection periods. The predicted correlation is considerably greater than is observed in most published data sets. Over-dispersion is thus generated by variability between hosts which has components that remain constant between initial and reinfection and also components which vary between infection periods. The model is modified to account for those two sources of variability, and the result applied to published data to determine the contributions made by short and long-term factors to the observed distributions.
Genetic heterogeneity withinEchinococcus granulosus: isolates from different hosts and geographical areas characterized with DNA probes
Authors: McManus D. P. , Rishi A. K. 
Published: June 2009

SUMMARYA segment of the ribosomal RNA gene ofSchistosoma mansoniand a DNA fragment specific toEchinococcus granulosus, cloned in plasmids, have been used as DNA probes to assess the extent of genetic variability withinE. granulosusand some distinct strains have been identified. The DNA analysis, involving restriction endonuclease digestion and Southern blot hybridization with the probes, did not demonstrate any significant genetic variation within the U.K. horse/dog or sheep/dog strains but confirmed the distinctiveness of the two strains shown in previous studies. The sheep/dog strain was shown to be cosmopolitan in its distribution and fertile bovine material originating from the United Kingdom, Kenya, Spain and India conformed to this strain by DNA hybridization. In contrast, cattle isolates from Holland produced markedly different DNA hybridization banding profiles indicating that cattle can harbour more than one strain ofE. granulosus. Similarly, it was shown that goats can harbour two different strains ofE. granulosus, the sheep/dog strain and a form which infects camels. The strain ofE. granulosusinfecting equines in Spain and Ireland is genetically identical to that infecting horses in the United Kingdom. There is also a different strain infecting pigs in Poland and Yugoslavia. This pig/dog strain appears to be very similar genetically to the forms ofE. granulosuswhich use camels and goats as intermediate hosts and is similar, though not identical, to the variant infecting Dutch cattle. It has been shown thatE. granulosusmaterial, fixed for a prolonged period in ethanol, or lyophilized, is amenable to DNA analysis and that it is possible to characterize the DNA of a single adult worm.
Eimeriaspecies infecting wood mice (genusApodemus) and the transfer of two species toMus musculus
Authors: Nowell F. , Higgs S. 
Published: June 2009

SUMMARYCharacteristics of four species ofEimeriaisolated fromApodemus sylvaticusare described. From oocyst morphology, three are identified asE. apionodes, E. hungaryensisandE. uptoni, the fourth being unnamed. Cloning demonstrated that oocysts ofE. hungaryensiswere polymorphic. Previous literature relating to the taxonomy is discussed and discrepancies outlined. Species isolated fromA. sylvaticuswere not transmissible toClethrionomys glareolus, but bothE. hungaryensisandE. apionodeshave been passaged through immunosuppressed laboratory mice, the former species more than 16 times. In bothA. sylvaticusand immunosuppressed laboratory mice, endogenous development ofE. hungaryensisoccurred mainly in enterocytes near the tips of the villi in the first half of the small intestine, with a few parasites in the rest of the small intestine and into the large intestine. The pre-patent period was 2 days in both hosts but oocyst output was higher in the natural hosts.E. apionodesparasitized enterocytes on the sides or at the base of the villi, mainly in the last 90% of the small intestine with a few parasites in the large intestine. The pre-patent period was 7 days. Parasites, probablyE. hungaryensisandE. apionodes, were also isolated fromA. flavicollis.
Cultivation of Blastocrithidia triatomae (Trypanosomatidae) on a cell line of its host Triatoma infestans (Reduviidae)
Authors: Reduth Dagmar , Schaub G. A. , Pudney Mary 
Published: June 2009

SUMMARYBlastocrithidia triatomae parasitizes vectors of Chagas' disease and is very difficult to cultivate in conventional media. However, co-cultivation with a cell line of its host Triatoma infestans (TI-32; in Schneider's Drosophila medium supplemented with 20% foetal calf serum and 10% tryptose phosphate broth) led to vigorous growth at 24 or 28 °C without an adaptation phase. More than 60 primary cultures were initiated successfully without any failures. Subcultures could be started immediately at weekly intervals. The doubling time was similar in both the primary cultures (41 h) and the 33rd subculture (39 h). The importance of the reduviid cells for B. triatomae became clear after removal of the insect cells, when multiplication of epimastigotes stopped and mainly cysts were formed. Cysts produced in vitro were infective for reduviids. Scanning electron microscopy showed that B. triatomae attached to the host cells, inserted its flagellum into them and destroyed them.