bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population biology ofBothriocephalus rarusThomas (1937) in the red-spotted newt,Notophthalmus viridescensRaf
Authors: Jarroll E. L. 
Published: June 2009

SUMMARYThe distribution and abundance of the cestodeBothriocephalus rarusinfecting red-spotted newts,Notophthalmus viridescens, were studied for over 1 year in an artificial pond in West Virginia, USA.Macrocyclops aterandMesocyclops edaxwere found to harbourB. rarusprocercoids experimentally, andM. aterwas confirmed as a natural intermediate host for this cestode. The recruitment ofB. rarusby newts coincided with the peak density ofM. ater, indicating thatB. rarusmay have adapted itself to the copepod life-cycle to increase the probability of successful parasite transmission. Infection was more frequent and of higher intensity in larval newts. The observed frequency distribution of cestodes in all segments of the newt population closely fits the negative binomial. The data indicated seasonal cycles in population structure, intensity of infection, maturation and reproduction. Recruitment of worms by adult newts occurred in June, July and August, at the time when the density of adult worms decreased.
Redescriptions of Eimeria irresidua Kessel & Jankiewicz, 1931 and E. flavescens Marotel & Guilhon, 1941 from the domestic rabbit
Authors: Norton C. C. , Catchpole Janet , Joyner L. P. 
Published: June 2009

SUMMARYEimeria flavescens and E. irresidua from the domestic rabbit are redescribed. The relatively smaller ovoidal oocysts of E. flavescens which measure on average 31·7 × 21·4 μm, possess a wide micropyle at the broad end. First-generation schizonts of this species develop deep in the glands of the lower small intestine. Merozoites migrate to the caecum and colon where second, third and fourth-generation schizonts develop in the superficial epithelium followed by the fifth-generation schizonts and gametocytes which form in the glands. In young Dutch rabbits E. flavescens is very pathogenic; low doses of oocysts produce a severe enteritis with high mortality and morbidity. The larger, broadly ellipsoidal oocysts of E. irresidua measure on average 38·4 × 23·2 μm and often possess a very small cryptic oocyst residuum. The endogenous stages develop in the small intestine only; first-generation schizonts in the glands and second-generation schizonts in the lamina propria whilst third and fourth-generation schizonts and gametocytes develop in the villous epithelium. E. irresidua is not pathogenic in young Dutch rabbits; even heavy infections produce only a transient pause in weight gain.
Studies on heterologous resistance betweenSchistosoma mansoniandFasciola hepaticain inbred rats
Authors: Ford M. J. , Taylor M. G. , McHugh S. M. , Wilson R. A. , Hughes D. L. 
Published: June 2009

SUMMARYFischer rats infected withFasciola hepaticashowed significant resistance toSchistosoma mansonichallenge, and vice versa, whereas immunization with 20 Krad-irradiatedS. mansonicercariae failed to protect againstF. hepaticachallenge, but did protect against homologous challenge. When groups of rats received intraperitoneal implants of newly excysted juvenile flukes, 20- to 22-day-old juveniles, or 8- to 10-week-old flukes, none was significantly protected againstS. mansonichallenge, whereas juvenile implants did protect against homologousF. hepaticachallenge. In passive transfer experiments in rats, serum fromF. hepatica-infected rats or rabbits protected recipients against homologous, but not heterologous challenge, and serum from rats vaccinated with 20 Krad-irradiatedS. mansonicercariae protected recipients against homologous, but not heterologous challenge. These experiments provide evidence that the mechanisms involved in homologous and heterologous resistance are different, the latter lacking immunological specificity. Microsphere injections inF. hepatica-infected rats demonstrated ‘shunting’ from the portal system to the systemic circulation. If migrating schistosomula are also ‘shunted’ inFasciola-infected rats, this, rather than immunologically specific effector mechanisms, might explain their failure to establish in the portal system.
Reduction of niridazole by metronidazole resistant and susceptible strains ofTrichomonas vaginalis
Authors: Yarlett N. , Rowlands C. C. , Yarlett Nuriza C. , Evans J. C. , Lloyd D. 
Published: June 2009

SUMMARYThe inhibitory effect of niridazole on hydrogen production by metronidazole-resistant (CDC-85) and susceptible (Cl-NIH)Trichomonas vaginalisstrains was investigated. The results show that niridazole is more effective than metronidazole in inhibiting hydrogen production by the resistant isolate. In CDC-85 aerobic inhibition requires a 4-fold increase in metronidazole concentration compared with that required anaerobically, but the corresponding factor for niridazole is only 1·5-fold. Reduction of the drug by a hydrogenosome-enriched preparation gave rise to a multiline electron spin resonance detectable signal, which is due to a nitrogen-centred radical.
Trichinella spiralis: immunocytochemical localization of surface and intracellular antigens using monoclonal antibody probes
Authors: McLaren Diane J. , Ortega-Pierres Guadalupe , Parkhouse R. M. E. 
Published: June 2009

SUMMARYA panel of immunologically and biochemically defined monoclonal antibody probes has been used in conjunction with immunocytochemical techniques to localize target antigens in sections of different life-cycle stages ofTrichinella spiralis. Monoclonals that immunoprecipitate surface components from adult worms, show reactivity with the surface but not with internal tissues of sectioned parasites. Reagents that immunoprecipitate radio-isotope labelled stage-specific surface components of muscle-stage larvae, however, react with the stichosome and gut lining of sectioned larvae, as well as with the surface. Monoclonal antibody probes that do not stain the surfaces of live, intact muscle larvae in immunofluorescence assays, but which immunoprecipitate solubilized surface glycoproteins, also show reactivity with cuticular and stichosomal antigens of sectioned larvae. The more powerful resolution provided by electron microscopy has localized the surface antigens to the epicuticle and the intestinal antigens to the brush-border microvilli. Of particular interest was the finding that antigens of muscle-stage larvae, known to confer protection upon recipient mice, also exist in the stichosome of adult parasites. This observation may shed some light on the fact that mice immunized with antigens from muscle-stage larvae show, in addition to reduced muscle larva burden, accelerated expulsion of adult worms. The implications of these data for stage specificity of immune responses to trichinosis are discussed.
Effects of anti-thymocyte serum on the eosinophil and lysophospholipase responses in mice infected withTrichinella spiralis
Authors: Adewusi K. , Goven A. J. 
Published: June 2009

SUMMARYAnti-thymocyte serum (ATS) was administered to CD-1 mice infected with 100Trichinella spiralislarvae and its effects on intestinal lysophospholipase (EC 3.1.1.5) activity, peripheral blood lymphocytes and bone marrow, peripheral blood and intestinal eosinophilia were assayed in the same experimental animal. The ATS caused a significant suppression of both the tissue lysophospholipase response and eosinophilia, in all three compartments, when compared to the values found in infected mice that were either treated with normal rabbit serum (NRS) or untreated. The suppressed eosinophil response and reduced lysophospholipase activity demonstrated a close temporal relation throughout the experiment. These findings support the hypothesis that helminth parasite-induced eosinophilia is the cause of increased lysophospholipase activity present in parasitized tissue and that the responses are thymus cell dependent.
Insect viruses as control agents
Authors: Payne C. C. 
Published: June 2009

SUMMARYVirus diseases have been reported from more than 800 species of insects and mites. Isolates of the baculovirus and cytoplasmic polyhedrosis virus groups have biological properties which should lead to their successful use as microbial control agents in integrated pest management programmes. These viruses infect the larval stages of many lepidopterous and hymenopterous pests, producing a chronic or lethal infection and the release of large quantities of relatively stable infective inclusion bodies (IBs). The IBs serve as the means by which the viruses are transmitted and persist outside the host. Younger larvae are more susceptible to infection than older stages, and this difference influences the timing of application and doses of virus needed for practical pest control. The high degree of host specificity of many isolates reduces their potential ecological hazard but also limits their use, particularly on crops where a complex of pests is established. Environmental persistence is also a limiting factor as virus is rapidly inactivated by ultra-violet light even when contained within IBs. The viruses persist for longer periods when transmitted within the host population, a feature of virus infections restricted to the insect gut.The practical use of insect viruses in horticulture and agriculture does not utilize their full epizootic potential, but takes advantage of their high pathogenicity and specificity. The baculoviruses of codling moth, andHeliothisspp. provide satisfactory pest control, but for their most cost-effective use it is important to determine the minimum dosage rates of virus required. It is encouraging that studies of the virus control ofPierisspp. have suggested that control achieved by the insecticidal use of a virus can be closely predicted from information on dosage-mortality responses, larval feeding rates and virus persistence. The stability of forest and grassland, and their high economic thresholds makes them ideal candidates for longer-term control. Viruses of the coconut rhinoceros beetle and european spruce sawfly provide examples of classical biological control where the viruses persist for long periods, are efficiently transmitted and act as natural regulators of their hosts. Virus control of pasture, and some forest, pests may be possible by manipulating enzootic viruses without the need for direct control measures. More frequently insecticidal applications are needed, providing control of limited duration which requires periodic ‘topping-up’.Few viruses are commercially-available; their selectivity and often small potential market, may limit industrial interest. However, improvements in virus production, formulation and a better understanding of virus epizootiology should lead to an increasing role for this group of insect pathogens in biological control.
Current status of nematodes for the biological control of insects
Authors: Petersen J. J. 
Published: June 2009

SUMMARYThis review highlights published research on the principal entomogenous nematodes that have potential as biological control agents of insects. The life-cycles and status of promising members of the families Allantonematidae, Diplogasteridae, Heterorhabditidae, Mermithidae, Neotylenchidae, Rhabditidae, Sphaerulariidae, Steinernematidae and Tetradonematidae are discussed. Emphasis is placed on attempts to control insect populations with these nematodes. Mass propagation of the Steinernematidae and Mermithidae are also discussed, including currentin vivoandin vitrorearing systems. A number of these nematodes show promise as biological control agents but commercial development has been slow because of environmental limitations, host specificity and inherent problems associated with manipulation of living organisms. Although some of these nematodes have been considered for commercial preparation, it appears that they will remain ‘on the shelf’ until the need for such biological control provides small businesses with the incentive to make them available for general use.
Fungi as biological control agents of arthropods of agricultural and medical importance
Authors: Hall R. A. , Papierok B. 
Published: June 2009

SUMMARYThere are many species of fungi attacking terrestrial and aquatic insects of agricultural and medical importance. Of these, few species have received much attention with a view to their use as biological control agents. The mechanisms of infection have been comparatively well studied, although many questions remain to be answered. The knowledge so far obtained has shed some light on the reasons for host specificity. Temperature, above all relative humidity, and their interactions are the most important physical factors influencing infection of terrestrial insects by entomopathogenic fungi and these are discussed in relation to epizootiological events. In aquatic environments, temperature, salinity and organic pollution are the important factors. In addition to these physical factors, numerous biotic factors at the level of the insect and the fungal pathogen influence both infection and spread of disease in insect populations. The complexity of the interactions of the biotic and abiotic factors makes it extremely difficult to study the influence of any one of these. Virulence of fungal pathogens and its measurement are discussed, together with the shortcomings of present bioassay systems; virtually no laboratory bioassay system exists which has been designed to yield data meaningful in the field. Mass-production techniques are described as are their inherent problems and those of formulation and storage. Finally, the achievements of fungal control of insects in the field are reviewed. Thus far, several species are mass-produced and are in widespread use, two of which,Verticillium lecaniiandHirsutella thompsonii, have been commercialized. More studies, ecological, fundamental and developmental are required in this field to realize fully the potential of other candidate fungi.
Parasitoids as biological control agents – a fundamental approach
Authors: Waage J. K. , Hassell M. P. 
Published: June 2009

SUMMARYThis review begins with a description of the parasitoid life-style and the ecological and evolutionary factors which generate the remarkable diversity of insect parasitoids. We then describe the various ways that parasitoids have been used in the biological control of insect pests, and survey their success to date. The use of parasitoids remains largely an art, aided by past experience of success and failure. A more fundamental approach, involving basic research and theory, has not as yet contributed significantly to practical biological control. We explore the potential for such a science of parasitoid use and review basic research on parasitoid ecology and evolution which is of particular relevance to biological control. Mathematical models are used to identify and examine those parasitoid and host attributes which lead to successful biological control. Factors such as parasitoid foraging behaviour, fecundity, larval survival and sex ratio are shown to be important in influencing the depression of host populations and/or the stability of host–parasitoid interactions after depression. Multiple release is discussed and a model for inundative release of parasitoids is explored.
Evolutionary implications of Leishmania amastigotes in circulating blood cells of lizards
Authors: Telford S. R. 
Published: June 2009

SUMMARYAmastigotes of 2 Leishmania species are reported from the Pakistani lizards Teratoscincus scincus (Gekkonidae) and Agama agilis (Agamidae) collected in western Baluchistan and north-central Sind, respectively. Parasites were seen only in blood cells, primarily within thrombocytes, and were detected on smears of peripheral blood. Slides made at 3-day intervals for 38 days from an infected hatchling T. scincus demonstrated an increase with time in the mean number of amastigotes/infected thrombocyte. No evidence of an infection focus in fixed cells of the viscera was found. It is suggested, in view of reports of amastigotes in circulating blood cells of hosts belonging to 5 genera, collected in 5 countries from India to France, that saurian Leishmania may behave simply as parasites of circulating blood cells, thus illustrating an early stage in the adaptation of leishmanias to the vertebrate host.
An experimental study of the effects of Nosema eurytremae (Microsporida: Nosematidae) on the liver fluke Fasciola hepatica
Authors: Canning Elizabeth U. , Higby G. C. , Nicholas J. P. 
Published: June 2009

SUMMARYA microsporidian parasite, Nosema eurytremae, was fed to Lymnaea trunculata infected with Fasciola hepatica. Microsporidian infection of the snail was always light, though spores were present in all tissues, but the rediae became heavily infected in the parenchyma. The proportion of infected rediae increased with time and was especially high in ageing infections. Although rediae were only lightly infected when examined before cercarial release began, the infections became progressively heavier, so that towards the end of the life of the snails a high proportion of rediae were totally destroyed and contained no cercariae. Cercarial output was significantly depressed over a long period of active shedding by snails which had been hyperinfected with 1 × 10 6 spores and some of the liberated cercariae were themselves infected.
Acid phosphatase activity demonstrated by intact Angiostrongylus cantonensis with special reference to its function
Authors: Maki Jun , Yanagisawa Toshio 
Published: June 2009

SUMMARYIntact Angiostrongylus cantonensis is able to hydrolyse glucose-phosphate esters, mononucleotides and p-nitrophenyl phosphate as well as β-glycerophosphate in vitro. Reciprocal inhibition studies suggest that the hydrolysis of such substrates is due to a non-specific phosphomonoesterase. Molybdate ions, which exert no effect on either the uptake of glucose or the production of lactate, inhibit the hydrolysis of glucose-1- phosphate in the external medium and simultaneously lower the production of lactate by the intact worms in vitro.
The development of the metacercaria of Maritrema linguilla Jäg., 1908 (Digenea: Microphallidae) in the intermediate host, Ligia oceanica (L.)
Authors: Benjamin L. R. , James B. L. 
Published: June 2009

SUMMARYThe first two phases in the growth of Maritrema linguilla in Ligia oceanica, which occur in unencysted specimens in the pleopod sinuses, from day 0 to day 28 post-infection (p.i.), include a 3-fold increase in size, an enormous increase in the relative size of the excretory bladder, metamorphosis of papilliform extensions of the tegument into microvilli and development of single pointed spines and cystogenous gland cells. The third phase, from day 29 to day 38 p.i., following migration to the dorsal haemocoel, includes production of 3 cyst wall layers, the loss of single pointed spines and a considerable decrease in the relative size of the excretory bladder. The fourth phase from day 39 to day 42 p.i., involves a further increase in body size and the formation of digitiform spines. The fifth, sixth and final phases from day 43 to day 120 p.i. first include the completion of the last two cyst wall layers and then an increase in body size and development of the digestive, excretory and reproductive systems to almost adult dimensions but sperm, ova, vitelline globules and eggs are produced only in the final host.
Enzyme polymorphism and the identity of Trypanosoma brucei gambiense
Authors: Godfrey D. G. , Scott Catherine M. , Gibson Wendy C. , Mehlitz D. , Zillmann U. 
Published: June 2009

SUMMARYThirty-two isolates from man in known areas of Gambian trypanosomiasis, in the Sudan, Kenya, Zaire, Nigeria, Ivory Coast, Burkina Faso, Liberia and Senegal, were examined by isoenzyme electrophoresis of 11 enzymes. Comparisons were also made with our previously published results on 23 other stocks of similar origins, which had been examined in the same manner. All those stocks of low initial virulence to laboratory rodents, which thus conform to the accepted view of the behaviour of Trypanosoma brucei gambiense can be identified by characteristic combinations of enzyme patterns, especially certain aminotransferase markers. A limited study of superoxide dismutase polymorphism suggested a further marker of value. The isolates of high initial virulence to rodents, which are thus behaviourally akin to T. b. rhodesiense, did not share these characteristics. We conclude that there exists a homogeneous group of trypanosomes of wide dispersion throughout tropical Africa, characterized by certain isoenzyme combinations and low initial virulence to rodents, which corresponds to the classical concept of T. b. gambiense. The features of limited antigenic repertoire, high resistance to normal human serum and restriction fragment length polymorphisms of the genes for certain variant surface glycoproteins also appear to be characteristic of this group.
Experimental infection of laboratory rats with Corynosoma semerme (Acanthocephala)
Authors: Valtonen E. Tellervo , Helle Eero 
Published: June 2009

SUMMARYTen albino rats injected with hydrocortisone were infected with 36–66 cystacanths of Corynosoma semerme in order to study the course of infection in a warm-blooded animal. Surveys were carried out 2, 5, 8, 14, 18, 21 and 28 days after infection. Recovery decreased from 60% after 2–5 days to 22% after 28 days. The proportion of males dropped markedly before the 8th day of infection. The worms were concentrated in the latter half of the intestine, the males being in a more anterior location on average. The males matured between the 2nd and 5th day of infection. Disintegrated ovaries were observed in some of the 2-day-old females, but mature free ovaries were seen only in 5-day-old females. By the 14th day many females contained fully developed eggs, but it was only after the 18th day that the number of eggs increased considerably. Male worms were not encountered in the 4-week-old infection. The females were longer than the males. In the present study, experimental infections are compared with other acanthocephalan infections in both birds and mammals.
An unusual structural organization to the gut of a digenetic trematode, Fellodistomum fellis
Authors: Halton D. W. 
Published: June 2009

SUMMARYAn ultrastructural examination of Fellodistomum fellis has revealed that the caecal lining consists of 2 distinct components: (a) cup-shaped digestive cells and (b) a pleomorphic layer of cytoplasm which supports and separates individual digestive cells. The digestive cells sequester host blood components within apical pockets formed by lamellated extensions of the cell surface, and undergo asynchronous, cyclical transformations in morphology associated with extracellular digestion and with the extrusion to the gut lumen of pigmented digestive residues. Histochemical tests and elemental analysis of the pigment suggest that it is a ferripor-phyrin, haematin. In the anterior portion of the caecum the supporting cytoplasmic layer is in continuity with the oesophageal tegument and snares the same ultrastructure. It is concluded that the digestive cells are supported by an extension of the foregut tegument.