bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interactionin vitrobetween bovine immunoglobulin and juvenileFasciola hepatica
Authors: Duffus W. P. H. , Franks D. 
Published: June 2009

SUMMARYFreshly excystedFasciola hepaticapossess an outer glycocalyx which stimulates an antibody response in cattle infected withF. hepaticametacercariae. Sera from animals receiving either a single or a double infection were examined for levels of IgM, IgG1and IgG2specific for the outer glycocalyx of intact live juvenileF. hepatica. High levels of specific IgG1were found to predominate. Using positive sera in an indirect fluorescent antibody assay, the bovine immunoglobulins labelled the outer glycocalyx in a characteristic reticulated pattern. On incubation at 37 °C this pattern rapidly broke up into discrete clumps and progressed until the entire antibody–outer glycocalyx complex was shed. The shedding phenomenon was shown to be continuous and, by using preparations of Fab fragments, was not due to the bivalent binding of the sensitizing antibody.
Reversibility of the effects of the host immune response on the intestinal phase of Trichinella spiralis in the mouse, following transplantation to a new host
Authors: Kennedy M. W. , Bruce R. G. 
Published: June 2009

SUMMARYOn day 10 of a primary infection of Trichinella spiralis in NIH mice, when adult worms were in the process of being expelled, their fecundity was markedly depressed. Upon transplantation to new host mice, the worms were able to establish successfully in their usual position in the anterior small intestine, even if originally recovered from the large intestine of mice expelling their worms, and these worms fully recovered their fecundity after 7 days in recipients. On day 5 of secondary and tertiary infections, immediately before loss of worms began, the adult worms were stunted and had a depressed fecundity. However, such worms, when transplanted, were able to establish in normal numbers and in a normal position in the intestine of recipient mice. Additionally, these worms were found to have developed a fecundity, and grown to a length, comparable to that of normal worms, but slightly less than that of control worms transplanted from day 7 of a primary infection, after 7 days in a new host. Electron microscopy showed that worms taken at the time of expulsion in primary and tertiary infections showed structural abnormalities, including large quantities of lipid in intestinal cells and somatic musculature and decreased quantities of stored glycogen. Upon transplantation to new host mice, these worms were found to have recovered a normal ultrastructural appearance within 7 days, although there was still evidence of a slightly elevated lipid and depressed glycogen content. It is concluded that immune expulsion of T. spiralis from mice does not involve irreversible damage to the worms.
Schistosoma mansoni: an examination of the reproductive status of females from single sex infections
Authors: Shaw J. R. , Erasmus D. A. 
Published: June 2009

SUMMARYThe variation in the development of the reproductive system of female Schistosoma mansoni from single sex infections is described. Vitelline cell development was assessed by staining for phenolic substances and the development of Mehlis' gland and the ovary by electron microscopy. Although there was considerable variation in the development of worms from individual mice harbouring infections of the same age, the mean values indicated that there was a low level of differentiation and turnover of vitelline cells in worms 30–200 days post-infection. The proportion of females which possessed mature vitelline cells showed a general increase with age. The ovary was always in an immature stage but the development of Mehlis' gland showed some variation. The results suggest that the stimulus given by the male to the female is not necessarily to initiate development of the reproductive system but to increase the rate of development of the vitelline gland and to co-ordinate the development of the entire reproductive system.
The life-cycle ofProsorhynchus crucibulum(Rudolphi, 1819) Odhner, 1905, and a comparison of its cercaria with that ofProsorhynchus squamatusOdhner, 1905
Authors: Matthews R. A. 
Published: June 2009

The adult ofP. crucibulumis redescribed to form a basis for comparison with the cercaria and metacercaria. Particular emphasis is given to the structure and function of the rhynchus, digestive system and reproductive system. Some features, notably prepharyngeal glands and spematophores, have not previously been recorded in this species.The sporocyst and cercaria which were found inMytilus edulisare described for the first time. Out of 6907 mussels examined from Borth Rocks, Cardigan Bay, 0·26% were infected withP. crucibulumand 0·06 % withP. squamatus. The cercaria of the latter is redescribed on a comparative basis with that ofP. crucibulum, to avoid confusion. The two cercariae are clearly distinguished by three features – flame-cell formula, shape of the excretory vesicle, and structure of the tail stem (this being bilobed inP. crucibulumand trilobed inP. squamatus). The significance of the two types of tail in securing attachment to the second intermediate host is discussed.Metacercariae ofP. crucibulumwere obtained experimentally in ‘O’ group specimens ofScophthalmus maximus. Three other species of fish, namelyLimanda limanda, Onus mustelusandGobius minutuswere also successfully infected. The metacercariae did not develop in the following fish:S. rhombus, Pleuronectes platessa, Cottus bubalisandBlennius pholis. Possible mechanisms which might account for host specificity within Pleuronectidae andScophthalmusare suggested.The development of the metacercaria in the connective tissues and musculature ofS. maximuswas followed over a period of 10 months. Within 1 month of infection the hyaline cyst of parasitic origin breaks down, enabling the parasite to feed directly on the host tissues. This feature is thought to account for the advanced development of the metacercaria, which 1 month after infection could clearly be identified with the adult on the basis of comparative morphology, and at 2 months resembles the adult in every respect except the development of the vitellaria. Egg production only occurs within the intestine ofConger conger, the definitive host.
Structural changes in the bovine nematode Haemonchus placei, that may be associated with host immune response
Authors: Harness E. , Smith K. , Bland Patricia 
Published: June 2009

The structure of H. placei adult worms, obtained from calves at 4, 7, 10 or 11–13 weeks after primary infection, has been studied. A reorganization of rough endoplasmic reticuhim in the cytoplasm of the gut cells was seen at 10 weeks and this was followed by marked vacuolation of many of these cells, associated with an increase in lipid production. Increases of lipid were also found in the hypodermis, lateral cords and occasionally muscle cells of worms examined at 11–13 weeks after infection.It is suggested that these changes are the result of the host immune response, because they resemble changes which occur in the rat nematode Nippostrongylus brasiliensis and which are known to be caused by host immunity.
Histochemical studies on microfilariae
Authors: Simpson M. G. , Laurence B. R. 
Published: June 2009

Microfilariae belonging to the genera Brugia, Loa and Wuchereria have been stained by a wide variety of histochemical methods. The results are recorded in eight Tables.The sheath of the microfilaria contains polyanionic material, probably polysulphate, periodate reactive mucosubstance, sulphur-protein and complex lipids. The fluid within the sheath is also polyanionic.The cuticle of the microfilaria is stabilized by disulphide bonds possibly in a collagen but it was not possible to demonstrate collagen by staining. The cuticle also contains a periodate reactive G mucosubstance and complex lipids. The annular grooves of the cuticle also contain a periodate unreactive mucosubstance. Certain areas of the cuticle, around the excretory pore, the pores of the Schwanzgebilde, and the cephalic structures - oral ring, hook and spines - are hardened by deposition of a keratinous scleroprotein. Some reactions of the cuticle may be masked by the presence of basic protein.The excretory vesicle contains polyanionic material but there was no clear evidence that the polyanionic material within the fluid in the sheath came from the excretory vesicle. The excretory vesicle, the anal vesicle and the subcuticular cells contain periodate reactive G mucosubstance. Most RNA staining was found in the excretory vesicle, the excretory cell, the anal vesicle, the rectal cells and the G cell.The pharyngeal thread, the Innenkörper, the rectal cells and the anal vesicle represent the modified gut of this first stage larva. The pharyngeal thread appears to consist largely of a protein-mucosubstance complex that can be unmasked by oxidation. The Innenkörper contains a basic protein and acidic mucosubstance, possibly sialomucin, complex that can be unmasked by adjusting the electrolyte concentration of the staining media.The relevance of some of these techniques in the analysis of possibly unique invertebrate structures is discussed briefly.We thank Dr D. A. Denham, Mr P. R. N. Pester and Dr T. Ponnudurai in particular, and many other correspondents, for supplying us with microfilariae for staining. This work was supported by a grant from the Medical Research Council of Great Britain.
Protective antibodies in infections with Eimeria maxima: the reduction of pathogenic effects in vivo and a comparison between oral and subcutaneous administration of antiserum
Authors: Rose M. Elaine 
Published: June 2009

Crude globulin fractions were prepared from the pooled serum of chickens 14 days after their inoculation with oocysts of Eimeria maxima (‘immune’ globulin) and from the pooled serum of similar but coccidia-free chickens (‘normal’ globulin). The fractions were injected subcutaneously into young chicks which were challenged with large numbers of oocysts and whose weight gains over the next 7 days were measured. The weight gains in all infected groups of chicks were lower than in uninfected and uninjected controls, but the gains in groups of chicks injected with ‘immune’ globulin preparations were higher than in groups given ‘normal’ globulin. Oocyst production in the groups given ‘immune’ globulin was very much lower than in the control groups, untreated or given ‘normal’ globulin.The reduction of oocyst production by antisera given by the subcutaneous and oral routes was compared. The weaker of two antisera had no effect when given orally but caused some reduction in oocyst numbers when given subcutaneously. A stronger antiserum produced some effect when given orally but was considerably more protective when given subcutaneously. The findings are discussed in relation to the mode of action of antibodies in protecting against infection.
The influence of Nematospiroides dubius on subsequent Nippostrongylus brasiliensis infections in mice
Authors: Conwil Jenkins D. 
Published: June 2009

The fecundity and longevity of Nippostrongylus brasiliensis was prolonged in mice previously infected with Nematospiroides dubius only when the former developed from the larval stage in those mice. Such worms appeared to be less immunogenic than worms which developed in mice never exposed to N. dubius.It is proposed that prolonged fecundity and longevity resulted from an adaptation undertaken by the worms in the face of host antibodies which had been developed against the pre-existing N. dubius infection.
Studies on site finding and site specificity of Eimeria praecox, Eimeria maxima and Eimeria acervulina in chickens
Authors: Long P. L. , Millard B. J. 
Published: June 2009

Sporozoites of 3 species of Eimeria were introduced into the caecum of young chickens. E. praecox and E. maxima failed to develop in this site, but light infections of E. acervulina were detected. Infection of the small intestine with all 3 species occurred when sporozoites were introduced via the caecum.Infections were produced when mucosal scrapings of small intestine from birds, inoculated via the caecum 1–4 h previously, were inoculated orally to susceptible chickens. Experiments with 51Cr-labelled sporozoites of E. praecox introduced in the caecum, confirmed that small numbers of sporozoites are capable of migrating from the lower to the upper intestine. Sporozoites were not transferred with liver tissue from birds given sporozoites via the caecum but were transferred with the liver of chickens given sporozoites intraperitoneally.
Development of Isospora bigemina in dogs and other mammals
Authors: Dubey J. P. , Fayer R. 
Published: June 2009

The life-cycle of canine Isospora bigemina was studied in dogs, cattle, cats and mice. Under experimental conditions dogs served as both definitive and intermediate hosts. Unsporulated oocysts (11 × 12 μm) were shed in the faeces and sporulated outside the host within 12 h at 30–37 °C and 36 to 48 h at 23 °C. Sporulated oocysts measured 12 × 13 μm and contained 2 sporocysts which in turn contained 4 sporozoites. Sporocysts averaged 6 × 9 μm and sporozoites averaged 2 × 6 μm. Although no stages were found microscopically in tissues or in faeces of 23 dogs orally inoculated with sporulated oocysts, the oocysts were infectious because 5 of 14 dogs that ingested tissues of dogs fed oocysts, shed oocysts. Prepatent periods were 7 to 15 days; patency was 1–3 days. No dogs became ill. In the naturally infected dog and one experimentally infected dog, schizonts were found in epithelial cells, distal to the host cell nucleus at the tips of villi throughout the small intestine. Schizonts were 5–7 μm and contained 3–12 merozoites. In the naturally infected dog, gametes were found in the same location. Male gametocytes were 6–8 μm and contained 6–12 microgametes, and female gametes were 7–8 μm.Sporulated I. bigemina oocysts from a naturally infected dog were not infectious to cattle, cats or mice. Structurally identical oocysts were shed by 2 dogs after ingesting hearts and diaphragm from naturally infected cattle; these oocysts were also not infectious to cattle. Although dogs acted as both intermediate and definitive hosts under experimentation, this is not likely to occur in nature. A canine-bovine-canine cycle would appear to be the natural mode of infection but I. bigemina was not infectious to cattle under experimental conditions.
Respiration and carbohydrate energy metabolism of the lung-dwelling parasite Rhabdias bufonis (Nematoda: Rhabdiasoidea)
Authors: Anya A. O. , Umezurike G. M. 
Published: June 2009

SummaryAn investigation of the carbohydrate energy metabolism of Rhabdias bufonis, the lung-dwelling nematode parasite of the African toad, Bufo regularis, indicates that the nematode stores very little glycogen (0·137 ± 0·003% on a fresh weight basis) but does utilize oxygen in vitro. The intracellular distribution and high levels of activity observed for the enzymes phosphoenolpyruvate carboxykinase, pyruvate kinase, lactate dehydrogenase, malate dehydrogenase, malic enzyme and fumarate reductase suggest two alternative pathways of carbohydrate energy metabolism.
Gamete development in malaria parasites: bicarbonate-dependent stimulation by pH in vitro
Authors: Nijhout Mary M. , Carter Richard 
Published: June 2009

SummaryGametogenesis in Plasmodium gallinaceum involves bicarbonate-dependent processes and requires a continuous supply of glucose (presumably as an energy source). Emergence and exflagellation of gametocytes, in vitro, occur independently of the CO2 tension but are rigidly correlated with the pH of the external medium. In bicarbonate-saline gametogenesis is initiated only if the pH exceeds 7·7. Our results suggest that gamete development of malaria parasites is stimulated when infected blood is exposed to air because the decrease in the CO2 tension of the blood causes its pH to rise.
The in vivo and in vitro ananlysis of immunity to Trichinella spiralis in mice and rats
Authors: Despommier D. D. , Campbell W. C. , Blair L. S. 
Published: June 2009

Wistar-Furth strain male rats and CFW strain male mice were immunized against Trichinella spiralis using an antegenic fraction derived from a cell-free homogenate of mature muscle larvae.In rats, animlas immunized with 250 μg of antigen harboured singnificantly fewer (135000) muscle larvae 30 days after oral challenge than controls (231000). Furhter 7-day-old adult worms derived from immunized rats shed 48% fewer (P < 0·001) newborn larvae over a 24 h period in vitro than adult worms from non-immunized animals.Mice were injected with either 10 or 100 μg of antigen. In comparison with non-immunized controls, mice immunized with 100μg of antigen harboured significantly fewer adult worms at days 7 and 9 after oral challenge infection, while female worms recovered from immune mice on days 6–10 after challenge shed fewer newborn larvae in vitro. Finally, mice immunized with 100μg of antigen harboured significantly fewer (10391) muscle larvae at 30 days after challenge than did controls (47750).Immunization of mice with 10μ of antigen did not induce a statistically significant reduction in adult worms at either days 7 or 9 after challenge (P < 0·5). However, adult female worms from mice receiving 10μg of antigen still shed fewer larvae than did adults from control mice (P < 0·05). Mice immunized with 10μg of antigen harboured significantly fewer (13700) recoverable muscle larvae than did controls at 30 days after challenge (39000).
Trichostrongylus colubriformis infection of guinea-pigs: genetic basis for variation in susceptibility to infection among outbred animals
Authors: Rothwell T. L. W. , Le Jambre L. F. , Adams D. B. , Love R. J. 
Published: June 2009

SummaryTwo lines of guinea-pigs, whose susceptibilities to infection with the parasitic nematode Trichostrongylus colubriformis differ significantly, have been established. This difference is probably based on genetically determined differences between the ability of members of each line to bring about immune expulsion. of the parasite.
Catabolism of deoxythymidylate in some trypanosomatids
Authors: Chalabi K. Al , Gutteridge W. E. 
Published: June 2009

An initial observation converning the failure of [3H]thymidine at high specific activity to be incorporated into the DNA ofCrithidia fasciculatafor more than a brief intitial period has been correlated with the presence at high specific activity in the organism of thymidine phosphorylase activity with an equilibrium in the direction of catabolism. This enzyme degrades thymidine to thymine which is not utilized by the organism. The enzyme has also been shown to be present in a number of other trypanosomatids, including the culture forms ofTrypanosoma cruzi, where the specific activity was nearly as high as that inC. fasciculata.Evidence is presented that inC. fasciculata, the culture forms ofT. cruziand possibly other species of trypanosomatid, the thymidine phosphorylase, together with a thymidylate phosphatase, forms a catabolic pathway which degrades thymine nucleotides to thymine, which is then excreated. About 60% of the thymine nucleotides made by organisms appear to be matabolized through the pathway, suggesting that their synthesis is not subject to completely effective regulatory control.
Parasitic protozoa of the blood of rodents: a revision of Plasmodium berghei
Authors: Killick-Kendrick R. 
Published: June 2009

Lowland populations of the Plasmodium berghei group are compared with strains from the highlands of Katanga, Republic of Zaire, and it is concluded that the former warrant separate specific status. It is proposed that Plasmodium berghei yoelii of the Central African Republic be raised to a species, P. yoelii, and the lowland subspecies from the CAR, Brazzaville and Nigeria be moved to this species as P. y. yoelii, P. y. killicki and P. y. nigeriensis. P. berghei from Katanga would then revert to a monotypic species.Differences between P. berghei and P. yoelii are in distribution, hosts, optimum temperatures of sporogony, sizes of mature oocysts and of sporozoites, rates of growth and minimum maturation times of tissue schizonts in the liver of the white rat, the forms of six enzymes and the DNA.Differences between three subspecies of P. yoelii are in distribution, the sizes of mature oocysts and of sporozoites, sizes of tissue schizonts in the liver of the white rat, the effect of tissue forms on the nuclei of infected parenchymal cells and the electrophoretic forms of the enzyme GDH.
The water dynamics of stages ofDitylenchus dipsaciandD. myceliophagusduring desiccation and rehydration
Authors: Perry R. N. 
Published: June 2009

Interference microscopy has been used to study the rate at which water enters and is lost from larval and adult stages ofDitylenchus dipsaciandD. myceliophagus. It is shown that the cuticle of the dry nematode, irrespective of stage, is completely permeable to water. In contrast, marked intra– and interspecific differences were found in the rate at which stages dry at 0 and 50% relative humidity. All stages ofD. myceliophagusdry very rapidly: in this species, death, as a consequence of severe desiccation, appears to be linked to a lack of any marked ability to control water loss. ForD. dipsaci, those stages known to survive desiccation will appear to be the slower dryers. In general, the “order of performance” in slowing the rate of drying is the same as the order previously found for survival of desiccation. Both the 4th– and, to a lesser extent, the 3rd–stage larvae ofD. dipsacishow evidence of an intrinsic ability to control water loss.An analysis of the drying curve for 4th–stage larvae ofD. dipsacisupports the indications of interference photographs that the rate of drying is slowed by a decrease in permeability of the drying cuticle.Vacuum desiccation studies further demonstrate the remarkable ability of the 4th–stage larva ofD. dipsacito control its rate of drying. The survival of 4th– and 3rd–stage larvae ofD. dipsaciis diminished by very rapid drying, and the survival of other stages of this species and larval and adult stages of D. myceliophagus is precluded. The decrease in survival of the 4th–stage larvae ofD. dipsaciis shown to be associated with a more rapid rate of water loss.
Effect of the expulsion phase of Trichinella spiralis on Hymenolepis diminuta infection in mice
Authors: Behnke J. M. , Bland P. W. , Wakelin D. 
Published: June 2009

The rapid elimination of the intestinal phase of Trichinella spiralis in NIH mice is associated with progressive inflammation of the intestinal tract. The non-specific effects of this inflammation were studied in. mice concurrently infected with an unrelated parasite, Hymenolepis diminuta, which does not stimulate a visible inflammatory response but is also immunologically rejected by this strain of mice.It was demonstrated that the rejection phase of T. spiralis infection had a marked effect upon the growth and survival of H. diminuta,. The cestode either failed to establish or to grow; if the worms were already strobilate when inflammation developed then destrobilation occurred. There was no cross–immunity between the parasites, nor was the interaction a direct consequence of inter–specific competition.