bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oogenesis and egg-shell formation inAspiculuris tetrapteraSchulz (Nematoda: Oxyuroidea)
Authors: Wharton D. A. 
Published: June 2009

SUMMARYThe ovary ofAspiculuris tetrapterahas a prominent terminal cap cell. This is considered to be part of the ovarian epithelium. Oogonia detach from the short rachis and increase in size from 6 to 60 μm; accumulating hyaline granules, shell granules and glycogen. The hyaline granules persist in the egg cytoplasm after shell formation has been completed and are considered to be lipoprotein yolk. The shell granules contribute to the non-chitin fraction of the chitinous layer. A classification of the cytoplasmic inclusions of the nematode oocyte is proposed. Upon fertilization a vitelline membrane is formed which constitutes the vitelline layer of the egg-shell. The chitinous layer is secreted in the perivitelline space, between the vitelline layer and the egg oolemma. Upon completion of chitinous layer synthesis, the egg cytoplasm contracts away from its inner surface. The material of the lipid layer is secreted at the surface of the egg cytoplasm and adheres to the inner surface of the chitinous layer. During secretion of the chitinous and lipid layers by the egg cytoplasm, the uterine cells secrete the unit membrane-like external uterine layer and the crystalline internal uterine layer. A complex system of interconnecting spaces develops in the internal uterine layer. This system is open to the exterior via breaks in the external uterine layer. There is no direct involvement of the uterine cells in the formation of this structure.
Effects of a thermal effluent on the incidence and abundance of the gill and intestinal metazoan parasites of the black bullhead
Authors: Boxrucker J. C. 
Published: June 2009

SUMMARYEffects of thermal effluent on the incidence and abundance of gill and intestinal metazoan parasites of the black bullhead,Ictalurus melas, were investigated. A total of 472 bullheads from a thermal outfall area and an unaltered area of Lake Monona, Dane County, Wisconsin were examined. All parasites underwent a seasonal cycle in abundance with peak infections occurring in summer, except for the acanthocephalan,Pomphorhynchus bulbocolli, which underwent a seasonal cycle in abundance in the reference area but not in the outfall area. Thermal effluent had little effect on the incidence of the parasites. Differences in abundance between the outfall and reference areas were observed for all parasites but these differences were not always consistent nor statistically significant.P. bulbocolliwas more abundant in the reference area than in the outfall area in summer (P≤ 0·05). The monogenean,Cleidodiscussp. was more abundant in the reference area than in the outfall area in August (P≤ 0·05). The infections of the gill copepod,Achtheres ambloplitis, were higher in the reference area than in the outfall area in spring, June, August, and September (P≤ 0·05). Availability of infective larvae and variability in host feeding patterns were suggested as the controlling factors of the patterns of abundance observed.
Diplocystis tipulaesp.nov. (Sporozoa: Eugregarinorida), a parasite ofTipula paludosaMeigen (Diptera: Tipulidae)
Authors: Sherlock P. L. 
Published: June 2009

SUMMARYStages seen in the life-cycle ofDiplocystis tipulaesp.nov. parasitic inTipula paludosaMg., included a structure that was probably a trophozoite within the midgut epithelium of one host larva and gamonts that developed on the midgut wall in the haemocoele of the larvae. Syzygy occurred, usually in pairs, when the gamonts were about 200–300 μm in diameter. Initially, syzygous gamonts were bilobed but they quickly became spherical and were enclosed by a fine membrane to form a gametocyst 450–550 μm in diameter. Early stages of gametogony were seen in one pupa; sporogony occurred in pupae and adults. The mean size of the round–oval oocysts was 7·14 × 6·26 μm. Individuals ofTipula oleraceaL. are also susceptible to infection withD. tipulae. This gregarine is considered to be a new species, independent of the gregarines of the gut lumen.
A reappraisal of the taxonomic status of Eimeria mivati Edgar and Seibold 1964, by enzyme electrophoresis and cross-immunity tests
Authors: Shirley M. W. 
Published: June 2009

SUMMARYAn examination of 2 strains of Eimeria acervulina var. mivati (since 1973 E. mivati has been regarded as a variant of E. acervulina) showed that previous confusion over the taxonomic status of E. mivati arose because the investigations were done using laboratory cultures of E. mivati which were contaminated with E. acervulina.Electrophoretic analyses of enzymes, host specificity and cross-immunity tests have revealed that:(1) The 1971 Houghton strain of E. acervulina var. mivati was a mixture of 2 parasites. (a) Passage of this strain in embryonating eggs resulted in a selection against that parasite previously characterized as E. acervulina. (b) The parasite which did reproduce in eggs did not immunize chickens against subsequent challenge with E. acervulina. This parasite is most likely E. mivati. (c) E. mivati recovered from eggs did, however, immunize chickens against challenge with a new field strain which was morphologically identical to E. mivati and characterized by the same electrophoretic forms of 2 enzymes.(2) A strain of E. acervulina var. mivati from the USA was also a mixture of E. acervulina and E. mivati.
Experimental studies of infection dynamics: infection of the definitive host by the cercariae of Transversotrema patialense
Authors: Anderson R. M. , Whitfield P. J. , Dobson A. P. 
Published: June 2009

SummaryThe number of cercariae of Transversotrema patialense which attach to the fish host Brachydanio rerio, during a fixed exposure period, is shown to be directly proportional to cercarial density within an experimental infection arena. The distribution of successful infections/host is shown to change from a random pattern to an over-dispersed form as cercarial exposure density or duration of host exposure to infection increases. A stochastic simulation model is used to demonstrate that small differences in host susceptibility to infection, within a population of hosts, can generate patterns of dispersion in parasite numbers/host similar to those observed in the experimental studies. Differences in host behaviour, during the period of exposure to infection, are thought to generate variability in host susceptibility to cercarial infection.
Effects of Aureo-S-700R on sporulation, viability and infectivity of ovine coccidial oocysts
Authors: Ajayi Jerry A. 
Published: June 2009

SummarySporulation rates of normal oocysts and oocysts isolated from lambs infected with coccidia and fed Aureo-S-700R for 25 days were studied at different temperatures. The viability and infectivity of the latter were also investigated.Temperatures of 5 and 10 °C inhibited sporulation of oocysts, but when the same oocysts were subsequently incubated at 25 °C, they sporulated. At 35 and 40 °C, sporulation was initially fast, but death and degeneration of oocysts occurred at these temperatures after 3 days.Normal oocysts sporulated faster and in greater numbers than oocysts isolated from medicated lambs; both kinds of oocysts sporulated best between 20 and 25 °C.Lambs inoculated with oocysts from medicated lambs passed fewer oocysts for a shorter period of time than lambs inoculated with normal oocysts. The former lambs gained more weight, passed better formed faeces, ate better and had higher PCV and haemoglobin values than the latter.
Eimeria tenella: immunogenicity of the first generation of schizogony
Authors: McDonald V. , Rose M. Elaine , Jeffers T. K. 
Published: June 2009

SUMMARYThe life-cycle of a precocious and attenuated line (WisF96) of Eimeria tenella, derived from the Wisconsin (Wis) strain, contained only the first of the three generations of schizogony undergone by the parent strain. The reproductive capacity of WisF96 was less than that of the parent strain by a factor of about 2000, but inoculation of chickens on two occasions with a large number of its oocysts induced resistance against challenge with oocysts, or with second-generation merozoites of Wis. The immunizing abilities of the attenuated line and its parent were compared by priming groups of chickens with numbers of oocysts of WisF96 or Wis, designed to produce infections of equal magnitude in terms of oocyst production (standard inocula), and then challenging with oocysts of Wis. The results suggested that an equivalent parasite mass of WisF96 was more immunogenic than Wis. This was confirmed by the finding that, even when the priming dose of Wis was increased 10-fold, the standard inoculum of WisF96 still produced the greater protective effect. These results indicate that the first generation of schizogony of E. tenella is highly immunogenic.
Plasmodium falciparum: regional differences in lectin and cationized ferritin binding to the surface of the malaria-infected human erythrocyte
Authors: Sherman I. W. , Greenan Jane R. T. 
Published: June 2009

SUMMARYThe distribution of anionic residues on the surface of erythrocytes infected withPlasmodium falciparumwas studied using cationized ferritin (CF) and transmission electron microscopy. CF staining of uninfected erythrocytes or erythrocytes infected with a knobless variant resulted in a dense and uniform distribution of ferritin particles; however, when red cells infected with a knob-inducing variant were exposed to CF, aggregates of ferritin particles were observed in the region of membrane elevation. Lectin binding to the erythrocyte surface was visualized by transmission electron microscopy using ferritin-conjugated lectins and lectin-fetuin-gold. No differences were observed in the lectin-binding patterns of malaria-infected or uninfected erythrocytes using WGA (wheat-germ agglutinin), RCA (ricin), andLimax flavuslectin. In distinct contrast to the uniform distribution of ferritin particles seen with these lectins was the appearance of clusters of ferritin-ConA over the knobby regions. Localized aggregates of ConA were not seen in knob-free areas or on the surface of red cells infected with a knobless variant. No significant differences were found in the agglutination reactions of normal and infected cells with theCancer antennariuslectin specific forO-acylated sialic acids.
Analysis of trypanosome variable antigen types in cultures of metacyclic and mammalian forms of Trypanosoma congolense
Authors: Luckins A. G. , Frame I. A. , Gray M. A. , Crowe J. S. , Ross C. A. 
Published: June 2009

SUMMARYCultured metacyclic forms of Trypanosoma congolense display a characteristic repertoire of metacyclic variable antigen types (M-VATs) similar to that exhibited in vitro in the tsetse fly. There appeared to be no change in expression of M-VATs in cultures of two stocks of T. congolense even after several passages, cryopreservation or long-term cultivation in vitro. Metacyclic forms transformed into mammalian forms when transferred to cultures of bovine aorta endothelial cells and whilst one stock retained expression of M-VATs without change even after 4 months, the other stock underwent antigenic variation within 14 days of transfer. Analysis of the M-VAT composition of mammalian forms of this stock using monoclonal antibodies showed that although the proportion of mammalian forms expressing certain M-VATs declined considerably, trypanosomes expressing one M-VAT increased proportionally to comprise 50 % of the population. In contrast, only small changes were seen in antigen expression in cultures of metacyclic trypanosomes from which mammalian-form cultures were derived. It was possible to produce in vitro, loss and reacquisition of variable antigen surface coat, similar to the differentiation process occurring when bloodstream trypanosomes are ingested by the tsetse fly and eventually develop into metacyclic forms.
Hymenolepis diminuta: influence of metacestodes on synthesis and secretion of fat body protein and its ovarian sequestration in the intermediate host,Tenebrio molitor
Authors: Hurd Hilary , Arme C. 
Published: June 2009

SUMMARYFemaleTenebrio molitorinfected with metacestodes ofHymenolepis diminutaexhibit elevated concentrations of female-specific proteins in their haemolymph and the origin of these has been investigated. Following a 4 hin vitroincubation with [14C]leucine, fat bodies from non-infected females secreted 13 times more protein than those from females 12 days post-infection. A comparison of the uptakein vivoof radio-isotope labelled amino acids by ovaries from non-infected and infected beetles of various ages revealed no differences; however, a 51·5% decrease in protein sequestration was detected in females 12 days post-infection. Electrophoresis of homogenates of radio-isotope labelled ovaries demonstrated that the majority of label was associated with vitellin sub-units. It is suggested that the decrease in vitellogenin sequestration associated with infection results in an increase in the haemolymph concentration of these proteins despite a concomitant reduction in their secretion by fat bodies. Both fat body synthesis and ovarian sequestration are under juvenile hormone control and it is proposed that metacestodes ofH. diminutamay cause a reduction in the concentration of this hormone in the intermediate host.
Trypanosoma musculi in CBA mice: trypanocidal mechanism eliminating dividing forms
Authors: Desbiens C. , Viens P. 
Published: June 2009

SUMMARYLarge inocula of dividing form-enriched Trypanosoma musculi parasites, harvested from the peritoneal cavity of infected CBA mice, were given intravenously to mice at various times during the infection. Mice infected for 10 or 15 days (including T cell-deprived, infected mice) eliminated dividing parasites from the blood within a few min, whereas those at earlier stages (1 or 5 days) were less efficient. The initial control of T. musculi parasitaemia thus appears to be due to a trypanocidal mechanism rather than reproduction-inhibiting factor (ablastin).
Effects of mermithid parasitism on the haemolymph composition of the larval blackflies Prosimulium mixtum/fuscum and Simulium venustum
Authors: Gordon R. , Condon W. J. , Edgar W. J. , Babie Sally J. 
Published: June 2009

SummaryHaemolymph of larval blackflies Prosimulium mixtum/fuscum and Simulium venustum parasitized by the mermithid nematode Neomesomermis flumenalis was compared with that of non-parasitized hosts with respect to protein, amino acid and carbohydrate composition. The mermithid depleted most protein fractions in a non-selective manner in both host species. In P. mixtum/fuscum, the levels of most amino compounds were reduced by mermithid parasitism, but these metabolites were approximately evenly divided into three categories (decreased, increased, unaffected by parasitism) in S. venustum. The mermithid caused a significant decrease of haemolymph glucose levels in both host species but did not affect blood trehalose concentrations. These effects of parasitism are discussed in relation to the nematode's nutritional requirements.
Transmission of Theileria parva by a population of Rhipicephalus appendiculatus under simulated natural conditions
Authors: Young A. S. , Leitch B. L. , Dolan T. T. , Newson R. M. , Ngumi P. N. , Omwoyo P. L. 
Published: June 2009

SUMMARYA 2 hectare paddock on the Muguga Estate, Kiambu District of Kenya (altitude 2100 m) free of Theileria parva-iniected ticks was seeded by applying Rhipicephalus appendiculatus nymphs to cattle infected with Theileria parva (Kiambu 4). It was estimated that over 50000 engorged nymphs fell onto the pasture from 4 cattle with high parasitaemias during the cold season (June). Samples of these ticks were placed in plastic cylinders under the vegetation in the paddock and sexual stages of T. parva were detected in gut lumen smears in these samples up to 21 days alter repletion. Zygotes were first observed to transform into kinetes on day 55 and parasites were first detected in salivary glands of adults on day 64. Moulting of the nymphs started on day 60 after repletion and was completed by day 87. Cattle introduced into the paddock showed their first infestation with adult R. appendiculatus on day 64 after repletion of the nymphs and the infestation level gradually increased. On day 76 after repletion, 17% of a sample of adult ticks infesting cattle showed salivary gland infections with T. parva and this increased to over 70% by day 150. From day 360 onwards, a decrease in both the percentage of ticks infected and the number of salivary gland acini infected/tick was noted. In addition, T. parva infections within the salivary glands required a longer period of feeding in the older ticks before they developed into sporozoites. Cycling of Theileria through ticks was prevented by the removal of female ticks before they completed repletion. Lethal challenge levels of T. parva for cattle existed in the paddock up to day 547 after repletion, after which introduced cattle showed no infection or only a sub-lethal infection. Cattle introduced into the paddock on day 808 after repletion showed no evidence of T. parva infection. The tick infestation of introduced cattle decreased markedly from day 368 and infestation had virtually ceased by day 808
Transmission of Theileria annulata (Dschunkowsky & Luhs, 1904) by Hyalomma excavatum (Koch, 1844)
Authors: Samish M. , Pipano E. 
Published: June 2009

SUMMARYTheileria annulata was transmitted transtadially by an Israeli strain of Hyalomma excavatum from larvae to nymphs and from nymphs to adults. However, the adults developing from larvae which engorged on infected calves and fed during the nymphal stage on non-infected calves, rabbits or gerbils (Meriones tristrami), did not transmit theileriosis. Suspensions of infected unfed nymphs or adults did not produce theileriosis but both nymphs and adults of the same batch became infective to cattle after 2 days of feeding. Suspensions of salivary glands or of whole ticks derived from infected adults that remained attached to rabbits for more than 7 days, were not infective to cattle.
Seasonal fluctuations and hypobiosis of gastro-intestinal nematodes of Awassi lambs in Iraq
Authors: Altaif K. I. , Issa W. H. 
Published: June 2009

SUMMARYThe results of an epidemiological study involving the estimation of worm counts of gastro-intestinal nematodes of lambs, during the period December 1978 to November 1979, in the Baghdad area are reported. Ostertagia spp. and Trichostrongylus spp. were the most abundant nematodes in the weaned lambs used in this study. Ostertagia spp. infection was present throughout the period of observation, the level of infection being the highest during early summer (May–June). Trichostrongylus spp. infection, however, reached a peak during July–August. In the tracer lambs the maximum population of Ostertagia spp. was found during February–March, while that of Trichostrongylus spp. could be observed only after mid-June. Other nematodes encountered were Haemonchus contortus and Trichuris sp. but they were only present in small numbers. The proportion of inhibited larvae of Ostertagia spp. was markedly high during the dry summer months. Little inhibition was noticed during autumn and the early winter months. It appears that if the seasonal inhibition of Ostertagia spp. in Iraq is brought about by an environmental stimulus acting upon pre-parasitic larval stages, that stimulus cannot be chilling or falling temperatures, as observed in temperate northern zones.
Echinococcus granulosus equinus: an ultrastructural study of murine tissue response to hydatid cysts
Authors: Richards K. Sylvia , Arme C. , Bridges Janine F. 
Published: June 2009

SUMMARYPeritoneal hydatids of Echinococcus granulosus equinus of 9 months standing in BALB/c mice occurred as free cysts or cysts within cyst masses. Both showed wide variation in size and in host tissue response, and all had a well-developed laminated layer separating the host tissue response from the germinal layer. In the smallest cyst-mass cysts the host tissue response was present as remnants of the initial cellular attack involving eosinophils. Slightly larger cyst-mass cysts possessed a primary macrophage invasion which phagocytosed the remnants of the initial attack and also, though to little effect, the laminated layer material. In the largest cyst-mass cysts a second macrophage invasion, of monocyte origin, had commenced and transformation stages of these cells to macrophages were observed. No fibroblasts surrounded individual cyst-mass cysts but they were present around the cyst mass, encapsulating it and possibly preventing further host cell invasion. Thus, the host tissue response around individual cyst-mass cysts remained ‘preserved’ at an early stage such as existed at the time of encapsulation. Small free cysts showed a primary macrophage invasion and transformation stages of cells of a secondary infiltration of peritoneal origin. Peripheral to the macrophages were fibroblasts demonstrating limited fibrinogenesis, and each cyst was surrounded by a layer of mesothelial cells. Large free cysts, also delimited by a mesothelial layer, possessed peripheral connective tissue, a deep fibrous layer and a monolayer of very compressed macrophages lying adjacent to the laminated layer. It is emphasized that an understanding of the host tissue response in cysts of different sizes and from different locations is an essential pre-requisite for the design of experimental studies.
Schistosoma mansoni: changes in elemental composition in relation to the age and sexual status of the worms
Authors: Shaw M. K. , Erasmus D. A. 
Published: June 2009

SUMMARYChanges during development in the elemental contents (Ca, P, K, Mg and S) of male and femaleSchistosoma mansonifrom both mixed and single sex infections have been measured for the first time. In mixed infections, there is a significant difference between the calcium content of male and female worms; female worms having between 2 and 3 times more calcium. In mature female worms from mixed infections, after an initial rise in the calcium content corresponding to the time when vitelline development occurs, the amount of calcium ranged from 0.36 to 0.65 mg/g dry wt, whereas the amounts in similarly aged male worms ranged between 0.19 and 0.32 mg/g dry wt. While the type of infection does not affect the calcium content of male worms, a significant difference in the calcium levels in female worms from mixed and single sex infections was found. The amount of calcium in females from single sex infections ranged from 0.21 to 0.39 mg/g dry wt and this is considerably less than the levels recorded in females from mixed infections. This difference in calcium content between mixed and single sex infections can be related to the differences in degree of development of the vitelline gland in the two types of female worm. The amounts of phosphorus, potassium, magnesium and sulphur in both male and female worms from both single and mixed infections are similar, although females from mixed infections contained slightly more phosphorus than either females from single sex infections or either type of male worm.