bluuebunny/crossref_metadata_2025 huggingface dataset:
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.
Haemocytic changes associated with the immune reaction of nematode-infected larvae of Orthellia caesarion
Authors: Nappi A. J. , Stoffolano J. G.
Published: June 2009

The immune reaction of larvae of O. caesarion against the nematode H. autumnalis is characterized by melanization of the cuticle of the parasite and the accumulation and fusion of host haemocytes to form a homogeneous, multinucleated capsule around the parasite. The immune reaction is manifested as a change in the haemocyte picture of the host long before there is any visible evidence of melanization and encapsulation. Differential haemocyte counts from host larvae at various stages of infection showed a decrease in the number of oenocytoids. These data, together with histological studies, indicate that oenocytoids play an important role in the melanization and encapsulation of the nematode. The apparent increase in the number of circulating haemocytes in parasitized larvae suggests that the haemocytes are stimulated to move out of areas where they are normally located and to react against the parasite.
Infectivity of cercariae of Schistosoma mansoni from snails on inadequate diets
Authors: Eveland L. K. , Ritchie Lawrence S.
Published: June 2009

A study was carried out to determine if snail nutrition influences infectivity of Schistosoma mansoni cercariae for mice. The percentage of worms recovered after infection was the chief criterion used to determine infectivity.
Six groups of Biomphalaria glabrata were raised on separate diets of (1) a standard formula with and without lettuce, (2) ‘Gaines Meal’ dog food (compressed pellets), (3) a commercial chicken feed, (4) Romaine lettuce, (5) squash, and (6) the rhizome of a Caladium plant. At 6 weeks the snails were infected and the cercariae resulting from the different snail infections were used to infect mice. Seven weeks later the mice were sacrificed and worms were recovered by perfusion.
Snails raised on squash, lettuce and the Caladium rhizome were only one-half the size of those receiving either the standard formula or the ‘Gaines Meal’ at the time of infection, and produced fewer than one-fifth as many egg clutches. However, the percentage parasitemia on all six groups of mice only varied from 49 to 55%, and there were no apparent differences in the size or development of the worms from the different groups of mice.
Orophryxus shiinoi gen.nov., sp.nov., an unusual phryxid (Crustacea, Isopoda, Bopyridae) parasitic upon a pontoniid shrimp from Zanzibar
Authors: Bruce A. J.
Published: June 2009

A new species of phryxid (Isopoda, Bopyridae) found attached in the pterygostome region of a pontoniid shrimp, Periclimenes grandis (Stimpson), is described. The only specimen, found at Mazizini, Zanzibar, has been placed in a new genus, which is defined here. The parasite, Orophryxus shiinoi gen.nov., sp.nov., is the only bopyrid which has been found attached in the pterygostomial region.
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 nature of resistance of immune puppies to superinfection with Toxocara canis: evidence that immunity affects second- but not fourth-stage larvae
Authors: Fernando S. T. , Vasudevan B. , Jegatheeswaran T. , Sooriyamoorthi T.
Published: June 2009

Fourth-stage larvae of Toxocara canis were introduced directly into the intestine of previously immunized puppies after laparotomy. They developed normally to the adult stage. In general 46–60% of the introduced larvae completed their development. By contrast the second-stage larvae introduced into similarly immunized puppies did not develop any further. No fourth-stage larvae or adult stages were noted in the nonimmunized controls.
The post-immunization sera of puppies formed precipitates at the oral orifices of the second-stage but not of the fourth-stage larvae and antibody response was detected following infection with large doses of infective ova but not small doses of infective ova or fourth-stage larvae.
Mesophryxus ventralis gen.nov., sp.nov., a phryxid bopyrid parasitic upon the pontoniinid shrimp Harpiliopsis beaupresi (Audouin)
Authors: Bruce A. J.
Published: June 2009

Mesophryxus, a new genus of phryxid isopod is described. The only species, M. ventralis, is a parasite of Harpiliopsis beaupresi (Audouin) to which it is attached on the ventral aspect of the sixth abdominal segment, behind the fifth pair of pleopods. Mesophryxus is most closely related to the genus Anomophryxus Shiino, from which it differs in the arrangement of appendages on the abdomen.
Juvenile and moulting hormones from nematodes
Authors: Rogers W. P.
Published: June 2009

Juvenile hormone and its analogues inhibited growth of Panagrellus redivivus and of the free-living stages of Haemonchus contortus. Substances extracted from nematodes had similar actions and also showed the activity of juvenile hormone in insects. Partly purified material from 1 g of freezedried juveniles of H. contortus contained about 200 Tenebrio units.
A comparative study of the reproductive system of mature, immature and ‘unisexual’ female Schistosoma mansoni
Authors: Erasmus David A.
Published: June 2009

The ultrastructure of the reproductive system of mature (54-day-old), immature (32-day-old) and females from unisexual infections of Schistosoma mansoni is described in detail. The uterus is tegumentary in structure but the vitelline duct and oviduct are complex and possess cilia as well as lamellae on their luminal surfaces. The characteristics of the cells forming the walls of the ducts suggests that they may have a digestive function. The posterior portion of the oviduct of the adult worm contains sperm which become enveloped by lamellae. The vitelline cells of the adult contain vitelline droplets, much lipid and little glycogen. A second type of body derived from endoplasmic whorls is also present. Mehlis's gland contains only one type of gland cell and these cells pass through the ootype wall and open into its lumen. The female from unisexual infections has an incompletely developed Mehlis's gland, an ovary in which the Golgi complexes do not produce typical cortical granules and has vitelline cells which remain immature. The oviduct, ootype and uterus are well developed in contrast to the vitelline duct.
A comparison with young, but not inseminated worms, suggests that the presence of sperm in the oviduct is not the major stimulus which induces maturation of the female worm.
Studies on the free pool of amino acids of the cestodeHymenolepis diminuta
Authors: Chappell L. H. , Read C. P.
Published: June 2009

Alteration of the free amino acid pool ofHymenolepis diminutawas observed following incubation of worms with a single exogenous amino acidin vitro, recovery from which depended upon the initial magnitude of alteration. The free amino acid pool of both rat small intestine andH. diminutawas rendered imbalanced after feeding a single dietary dose of proline. Recovery was more rapid in the host than in the parasite tissues. The quantitative dynamics of amino acid change with time were examined. The effects of amino acid variation upon the uptake and incorporation of lysine-C14into worm protein were examinedin vitro. Four amino acids altered lysine incorporation; aspartate stimulated incorporation while ornithine, arginine and histidine reduced variously the absolute amount of lysine uptake but produced relative stimulation of lysine incorporation. These data indicate that, in the system examined, short term variation of the free amino acid pool is unlikely to affect protein synthesis inH. diminuta. Data were obtained suggesting the possible occurrence of certain amino acid inter conversions inH. diminuta.
Cultivation ofTrypanosoma bruceisspp. in semi-defined and defined media
Authors: Cross G. A. M. , Manning J. C.
Published: June 2009

Semi-defined and defined media for the growth of culture forms ofTrypanosoma bruceisspp. have been developed by enrichment of tissue culture medium 199 with additional vitamins, amino acids, salts and other compounds. The semi-defined medium contains an acid hydrolysate of casein: in the empirically devised defined medium the casein requirement has been circumvented by inclusion of additional vitamins and amino acids. Both media are very hypertonic. Control of pH was found to be particularly critical for growth. The optimum temperature for growth in the semidefined medium was between 25°C and 28°C, but cells would undergo one or two division cycles at 37°C.
Prophryxus globicaudatus gen.nov., sp.nov., a hemiarthrinid bopyrid parasite of pontoniinid shrimps of the genus Coralliocaris Stimpson
Authors: Bruce A. J.
Published: June 2009

Prophryxus, a new genus of hemiarthrinid bopyrid from Kenya, is described. The only species, P. globicaudatus, is parasitic upon the shrimp Coralliocaris graminea (Dana). Prophryxus is considered to be most closely related to the genus Hemiarthrus Giard & Bonnier, from which it differs in the morphology of the abdominal appendages. It is most remarkable for the presence of a sucker-like organ on the dorsum of the cephalon, a feature unique in the Bopyridae.
Inhibited development in Haemonchus contortus
Authors: Connan R. M.
Published: June 2009

Inhibited development of Haemonchus contortus was studied in single experimental infections of worm-free lambs. Chilling of the infective larvae at + 4°C was without effect on the percentage of larvae subsequently becoming inhibited and a period of exposure to autumnal conditions was unnecessary to induce a high rate of inhibition. It was concluded that seasonal inhibition of H. contortus in East Anglia is brought about primarily by an environmental stimulus acting upon the preparasitic stages but that, unlike Obeliscoides cuniculi and Ostertagia ostertagi, this was not cold. It could be provided in a culture kept in the dark at 25 °C for 12 days. While the age of the host did influence the phenomenon, in that larvae were less inclined to inhibition in very young animals, it was concluded that this was not a primary factor in the aetiology.
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.
Schistosoma mansoni: the occurrence of microvilli on the surface of the tegument during transformation from cercaria to schistosomulum
Authors: McLaren Diane J. , Hockley D. J.
Published: June 2009

Microvilli are developed on the surface of Schistosoma mansoni schistosomula during penetration of the host skin; they form rapidly but are lost approximately 90 min after penetration. Identical microvilli are also formed on schistosomula which have penetrated a mouse skin preparation in vitro, and on schistosomula prepared by mechanical separation of the tail from the body of the cercaria. The microvilli, which are limited by the trilaminate tegumental membrane of the cercaria, eventually degenerate and are cast off from the surface of the tegument. There is little change in the surface area of the schistosomulum at this time, and the formation and loss of microvilli coincides with the replacement of the cercarial tegumental membrane by the new heptalaminate membrane. It is suggested that during the cercaria/schistosomulum transformation, some intramembraneous components of the original cercarial membrane may migrate into the new heptalaminate membrane and thus be retained, while other peripheral components such as the glycocalyx are almost certainly lost.
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.
Observations on the development of Haemonchus contortus in young sheep given a single infection
Authors: Coadwell W. J. , Ward P. F. V.
Published: June 2009

Worm free lambs 2–4 months old were given a single infection of 50 000 Haemonchus contortus larvae. The changes in packed red cell volume were compared with those of uninfected sheep and the infected sheep were divided into two groups according to the rate of change of packed cell volume. In group 1, packed cell volume fell sharply from the 10th day of infection and the sheep eventually died. In group 2, the fall was less marked and the packed cell volume returned to normal after about 40 days. The rates of increase of parasite body length and dry weight were compared for the two groups. Parasites in group 1 sheep grew more slowly than their group 2 contemporaries. Accurate planning of metabolic studies on H. contortus was made possible by using this information to predict the course of an infection and the size of the worms. Parasite development was also measured in sheep for which the packed cell volume was not recorded. Computer analysis showed that adult worm length increase did not follow a simple growth pattern starting from the last ecdysis, but consisted of a rapid elongation followed by a simple negative exponential increase. Dry weight increase also followed a negative exponential during the second phase. Measurements of dry weight as a percentage of wet weight indicated that the rapid elongation was possibly linked with cell enlargement by the uptake of water.
Respiration and carbohydrate energy metabolism of the lung-dwelling parasite Rhabdias bufonis (Nematoda: Rhabdiasoidea)
Authors: Anya A. O. , Umezurike G. M.
Published: June 2009

An 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

Gametogenesis 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).
Merozoite vaccination of rhesus monkeys against plasmodium knowlesi malaria; immunity to sporozoite (mosquito-transmitted) challenge
Authors: Richards W. H. G. , Mitchell G. H. , Butcher G. A. , Cohen S.
Published: June 2009

Five normal rhesus monkeys were infected with Plasmodium knowlesi sporozoites (A-strain); two developed rapidly fatal malaria and three chrinic relapsing infections. Vaccination with P. knowlesi (W-strain) merozoites (unmodified or formol-treated and freeze-dried) in Freund's complete adjuvant (FCA) did not inhibit pre-erythrocytic parasite development after challenge with A-strain sporozoites. However, the subsequent blood-stage infection was terminated in nine out of ten vaccinated monkeys even though the challenge strain was different form that used for vaccination. The degree of parasitaemia (0·01–0·70 %) and brevity of infection (1–12 days) in six animals vaccinated with untreated merzoites was similar to that observed after direct challenge with blood-stage parasites. Monkeys were equally resistant to sporozoite challenge given as the post-vaccination infection or administered 6 months after blood challenge. These results are discussed in relation to the development of a human malaria vaccine.
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

Two 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.
Histochemical observations on the distribution of various oxidative and phosphorylative enzymes in larval digeneans parasitizing Bithynia tentaculata (Mollusca: Gastropoda)
Authors: Reader Trevor A. J.
Published: June 2009

A comparative histochemical study is made on the distribution of succinate dehydrogenases, isocitrate dehydrogenases, malate dehydrogenases, glucose-6-phosphate dehydrogenases, α-glycerophosphate dehydrogenases, alcohol dehydrogenases, lactate dehydrogenases and glycogen phosphorylases in the tissues of sporocysts, rediae, cercariae and metacercariae parasitizing the gastropod mollusc Bithynia tentaculata. The results suggest that metabolic sequences resembling the conventional Embden–Meyerhoff pathway, the Pentose-Phosphate cycle and Krebs’ citric acid cycle may be operational in these larval digeneans. Heaviest enzyme activity is evident in the redial pharynx, the cercarial and metacercarial sucker and in the cercarial tail. Presumably the enzymes giving this heavy reaction form part of the energy producing mechanism for these active organs. Encysted metacercariae show a very heavy enzyme activity when compared with the sporocysts and developing cercariae of the same species. This is presumably associated with the breakdown of food storage materials, particularly glycogen, by these encysted stages.
A new species of Caryospora Léger, 1904 (Sporozoa: Eimeriidae) from an Australian snake
Authors: Cannon L. R. G. , Rzepczyk C. M.
Published: June 2009

A new coccidian parasite, Caryospora dendrelaphis sp.nov., with endogenous stages in the duodenal epithelium is described from the Australian colubrid snake Dendrelaphis punctulatus (Gray).
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.
Eosinophilia in Kenyan baboons (Papio anubis) induced byTrichinella spiralisandSchistosoma mansoni
Authors: Sturrock R. F. , Butterworth A. E. , Karamsadkar S. D. , Kimani R. , Imbuga M. , Houba V.
Published: June 2009

High primary doses ofTrichinella spiralisadministered orally to Kenyan baboons (Papio anubis) induced a marked but unpredictable eosinophilia which started 2–3 weeks after infection and persisted as erratic waves for at least 6 months. Low primary oral doses induced no eosinophilia but a later, high challenge gave an accelerated eosino-philic response, although the peak was lower than in high primary infection. Intravenous injection of infectiveT. spiralislarvae resulted in a predictable, rapid eosinophilic response which persisted for several weeks. Intravenous injection of a particulate material, Sepharose, gave no oesinophilic response.

PercutaneousSchistosoma mansoniinfection of baboons resulted in a two-stage eosinophilic response: an initial rise occurred about ⅔ of the way through the pre-patent period and was followed by a second rise at the onset of patency. After peaking, the eosinophilia waned erratically over the next 3 or 4 weeks.

A strong antibody response, measured by countercurrent imnruno-electrophoresis, was given in oral infections withT. spiralis, but intravenous injections elicited little or no antibody formation. Parasitological evidence indicated no cross-resistance toS. mansoniin baboons injected withT. spiralis9 days previously. Thus, the intravenous injection of infectiveT. spiralislarvae appears to be a suitable method of inducing experimentally a non-specific eosinophilia to investigate possible immune mechanisms toS. mansoniin the baboon.
The sites occupied by the acanthocephalan Pomphorhynchus laevis in the alimentary canal of fish
Authors: Kennedy C. R. , Broughton P. F. , Hine P. M.
Published: June 2009

The distribution of the acanthocephalan Pomphorhynchus laevis along the alimentary tract of several species of freshwater fish was studied in both natural and experimental infections. The parasite exhibits a clear preference for a particular region of the alimentary canal, which differs from host species to host species, but it is capable of surviving in all regions of the intestine. In some host species, but not in all, its growth rate may be reduced in regions outside of the preferred site. The parasite remains in the same site throughout the period of infection, emigrations occurring only preparatory to complete loss of the parasite from the host. The presence of cestodes in the region of the preferred site has no effect upon the distribution of the parasite. At high levels of infection the range of the parasite's distribution is extended. The feeding of larval parasites to fish by stomach tube also leads to an extension of range, whereas when fish are allowed to feed on cystacanths removed from their intermediate host the parasite establishes in a more anterior position than usual and in a site that it does not occupy to any extent in natural infections. It is concluded that the distribution of P. laevis in the alimentary canal offish is determined primarily by the process of liberation, activation and establishment of the parasite, and that it normally attaches in the first available space and remains there. Unsuitable physico-chemical or feeding conditions affect only its growth, not the site that it occupies. It is suggested that P. laevis may be atypical in this respect.
Nippostrongylus brasiliensis infections in mice: the immunological basis of worm expulsion
Authors: Love R. J.
Published: June 2009

Nippostrongylus brasiliensis infections in mice were terminated more rapidly than in rats and immunologically induced damage occurred earlier. Like rats, mice expelled damaged worms more rapidly than normal worms. Recipients of cells from the spleen or mesenteric node of immune mice expelled their worms by day 8 of the infection. Recipients of cells alone or antiserum alone did not expel their worms by day 5 but mice given both cells and antiserum expelled their worms by this stage of the infection. Damaged worms were expelled more rapidly than normal worms from mice given immune cells. This work indicates that antibodies and cells collaborate to expel N. brasiliensis from mice as has been shown to occur in rats.
Seasonal variation in numbers of the rabbit flea on the wild rabbit
Authors: Mead-Briggs A. R. , Vaughan J. A. , Rennison B. D.
Published: June 2009

Samples of rabbits were obtained throughout each month over the 4-year period 1967–70. All fleas were removed, sexed and counted and the reproductive condition of the rabbits recorded. Rabbit fleas Spilopsyllus cuniculi (Dale) were present on both sexes of rabbit at all times of the year. In each year significantly high numbers of fleas were found on the rabbits in January, February, March and April and significantly low numbers in August, September and October. Mean flea counts were significantly higher on female rabbits than on males during April, May and June. During the rest of the year counts from each sex of host did not differ significantly. There were significant differences in flea numbers between years. More female than male fleas were found on both sexes of host throughout the year. The rabbit population sampled is shown to be typical of post-myxomatosis populations with regard to breeding performance and juvenile mortality. The relationship of the observed patterns of change in flea numbers to host and flea breeding and to host behaviour, population size and structure is discussed.
Obligatory multiparasitism in the tussock moth,Orgyia leucostigma
Authors: Guzo D. , Stoltz D. B.
Published: June 2009

Orgyia leucostigmahaemocytes were able to encapsulate and destroy eggs ofHyposoterspecies, thereby preventing successful parasitism. When host larvae had previously been parasitized byCotesia melanoscela, however, this response was not observed, and 3 differentHyposoterspecies could be reared to maturity in the normally non-permissive host. Appropriate injection experiments established thatC. melanoscelavirus and venom were both required in order for successful parasitism byHyposoterto occur. Covalent cross-linking ofC. melanoscelaviral DNA led to an immune response againstHyposoterlarvae, but not eggs, suggesting that an active viral genome may be required for complete development ofHyposoterspecies in tussock moth larvae.
Attempts to induce resistance toSchistosoma mansoniandS. haematobium in Kenyan baboons (Papio anubis) using non-specific immunostimulants
Authors: Sturrock R. F. , Cottrell B. J. , Mahmoud A. A. F. , Chedid L. , Kimani R.
Published: June 2009

Non-specific immunostimulants were used in an attempt to protect baboons from infection by schistosomes. Subcutaneous vaccination with cord factor (4·50 mg) and muramyl dipeptide (4·56 mg) 6 days before percutaneous exposure to 3000Schistosoma haematobiumcercariae/baboon (c.p.b.) failed to protect naive baboons: baboons with a 7-month-old, 5000 c.p.b.S. haenzatobiumprimary infection had developed too strong a natural immunity to detect any protection attributable to vaccination. Subcutaneous vaccination with 0·4 ml of Bacillus Calmette-Guerin (BOG, 1–8 x 108colony forming units7sol;ml) 4 days before exposure to 1000 c.p.b.S. mansonigave a significant (38%) reduction in worm load compared with controls. However, vaccination with 0·8 (intramuscular) and 0·2 (intradermal) ml of BOG 11 days before exposure toS. mansoni800 c.p.b. did not protect naive baboons, nor did it significantly reduce challenge worm recovery from baboons with a 13-week-old, 500 c.p.b.S. mansoniprimary infection. Obvious pathology was seen at the site of vaccination in the first but not the second BCG experiment. These results partly support the findings in mice that non-specific macrophage and monocyte activators give partial protection against schistosome infections but they also illustrate that rodents and primates do not necessarily react identically. Hence, findings from rodent models should be extrapolated to man with some caution.
Impact of Nippostrongylus brasiliensis (Nematoda) on the serum albumin and amino acid concentrations of rats fed adequate or protein-deficient diets
Authors: Ash Caroline , Crompton D. W. T. , Lunn P. G.
Published: June 2009

Food intake, body weight changes, serum protein and amino acid concentrations were measured during the course of primary infections of Nippostrongylus brasiliensis in rats fed on either a 2% protein (casein) diet or a 16% protein diet (Oxoid 41 B). Total serum protein concentration declined from 77·84±5·35 mg/ml in uninfected well-nourished rats to 54±3·29 mg/ml in rats at 9 days post-infection (p.i.). A reduction from 47·80±2·78 to 40·38±5·62 mg/ml had occurred in protein-malnourished rats by day 6 p.i. The hypoproteinaemia was accompanied by significant hypoalbuminaemia in the protein-malnourished rats and concentrations fell from approximately 33 to 19 mg/ml at the time of peak infection. Six days after inoculation, a significant increase was detected in the concentration of serum amino acids in both well-nourished and protein-malnourished rats; the effect was more prolonged for non-essential than for essential amino acids. The results are discussed briefly in relation to recent work on the control of protein metabolism during malnutrition.
Partial purification of antigens collected duringin vitrocultivation of the larval stages ofTaenia pisiformis
Authors: Rickard M. D. , Katiyar J. C.
Published: June 2009

Larvae ofTaenia pisiformiswere culturedin vitroin medium containing 2·5, 5 or 20% (v/v) of normal rabbit serum (NRS). Greatest development occurred in 20% NRS, and the potency of antigens collected in medium from each culture tested by intradermal (i/d) skin tests in infected rabbits paralleled thein vitrogrowth rate of larvae. ‘Culture’ antigens from 5% NRS stimulated good immunity in rabbits to a challenge infection withT. pisiformiseggs, although they were poorly reactive in skin tests.

T. pisiformislarvae were also cultured in 10% (v/v) of nitrates of serum reduced to one-half of its volume by passage through 300 000 MW cut oif (XM300F) or 100000 MW cut off (XM100F) ultrafiltration membranes. Larvae cultured using XM300F had growth rates comparable with those cultured in 20% NRS, and the antigens released into the culture medium had equal potency in i/d tests and in stimulating protective immunity in rabbits. Larvae did not develop in XM100F orproduce skin-reactive or protective antigens.

Crude ‘culture’ antigen from cultures in 20% NRS was separated into 4 fractions by nitration on Sephadex G200. All of these fractions gave i/d skin reactions in infected rabbits. Fraction 3 (F3) was the most active, but was shown by acrylamide gel electrophoresis and immunoelectrophoresis to be highly contaminated with rabbit serum proteins. F3 was separated into fractions on DEAE-Sephadex A50, and the third fraction from this was as active as the original culture medium in i/d skin tests, but had only 5% of the original protein concentration. Electrophoresis demonstrated few serum contaminants, and 2 indistinct protein bands that were not present in a similar fraction of NRS.

Neither Sephadex G200 F3 nor DEAE-Sephadex F3 stimulated protective immunity in rabbits, suggesting that antigens stimulating immunity against the establishment ofT. pisiformisin rabbits and those provoking cell-mediated immune reactions may be different.
Milk-borne infection of rats with Strongyloides ratti and Nippostrongylus brasiliensis
Authors: Wilson Peter A. G. , Gentle Maureen , Scott Douglas S.
Published: June 2009

The numbers of mature worms which developed in young rats after their mothers were injected with 4000 L3 late in lactation were 1% (Nippostrongylus brasiliensis) and 24% (Strongyloides ratti) of the dose administered. The low value for N. brasiliensis validates the conclusion that milk is a real and important vehicle for infection in S. ratti since possible errors from skin invasion of the young would have been common to both species.

The level of mature S. ratti infection in lactating mothers in this experiment was negligible, 97–99% of the adult worms appearing in the offspring.

These results may indicate that the milk route is possible with N. brasiliensis even though it is quantitatively insignificant.
Laboratory studies with some recent anticoccidials
Authors: Ryley John F. , Wilson Robert G.
Published: June 2009

The activities of monensin, lasalocid and halofuginone against Eimeria tenella, E. brunetti and E. necatrix have been studied under laboratory conditions. Complete control of experimental infections in the chick, separable from toxicity, was not obtained with monensin, but was achieved with the other two compounds at levels of 150 and 6 ppm in the food respectively. All three compounds appear to inhibit coccidial development very early in the life-cycle, and to have a fairly rapid lethal effect, monensin and lasalocid more so than the febrifugine derivative. In vivo observations have been supplemented with in vitro studies. Some discussion of the difficulties of relating laboratory experiments to field performance is given.
Genetic factors in susceptibility of Biomphalaria glabrata for different strains of Schistosoma mansoni
Authors: Richards Charles S.
Published: June 2009

Biomphalaria glabrata selected for genetic differences in susceptibility to infection with a Puerto Rican strain of Schistosoma mansoni were exposed to miracidia of a strain of S. mansoni from St Lucia. The St Lucian strain was less infective than the Puerto Rican. Results suggested that in snails susceptible to the Puerto Rican S. mansoni, differences in susceptibility to the St Lucian strain were determined by a single gene, with insusceptibility dominant.
Nematode parasites of Puerto Rican tree frogs, Eleutherodactylus spp: two new species and a proposal of Poekilostrongylus gen.nov. (Trichostrongylidae)
Authors: Schmidt Gerald D. , Whittaker Frederick H.
Published: June 2009

Poekilostrongylus puertoricensis gen.nov., sp.nov. is proposed for nematodes recovered from Eleutherodactylus coqui, in Puerto Rico. The new genus is similar to Oswaldocruzia Travassos, 1917, but lacks longitudinal ridges on the cuticle. Oswaldocruzia lenteixierai Viqueras, 1938, is partially redescribed, and a key to the genera of the Oswaldocruziinae is given. Thelandros (Parathelandros) garciai sp.nov. is described from E. antillensis and E. portoricensis. Strongyloides sp. was found in E. antillensis and Aplectana spp. (females) were recovered from E. locustus, E. richmondi and E. coqui.