bluuebunny/crossref_metadata_2025_split huggingface dataset:
The excretory system of nematodes: structure and ultrastructure of the excretory system of Panagrellus redivivus, Ditylenchus myceliophagus with some observations on D. dipsaci and Heterodera rostochiensis
Authors: Narang H. K. 
Published: June 2009

The structure and ultrastructure of the excretory system of Panagrellus redivivus, Ditylenchus myceliophagus, D. dipsaci and the second-stage larvae of the Heterodera rostochiensis are described. Panagrellus has two lateral ducts, a median duct and a gland. The two lateral ducts are joined over the anterior part of the oesophageal bulb to form a loop. Anteriorly this loop continues as a median duct, which opens to the exterior in an excretory pit, part of the system lies free in the pseudocoelom. The lumen of the lateral excretory duct and the greater part of the median duct is surrounded by capitate tubules, which open into the lumen of the excretory duct. Capitate tubules develop by the invagination of the hypodermal membranes and lie embedded in thick cytoplasm surrounded by mitochondria. Ensheathed in cell membranes the excretory duct forms an anastomosis in the loop and at three other places along the length of each lateral excretory duct. At these regions there are nerve endings. The excretory gland opens posteriorly into the loop and is full of Golgi complexes, endoplasmic reticulum and secretory granules.In the system of Ditylenchus and the second-stage larva of Heterodera the right lateral duct is absent while the left lateral excretory duct continues anteriorly past the median excretory duct; a true loop is not formed. The median excretory duct lies embedded almost throughout its length in the excretory gland. Capitate tubules are present along the length of the lateral excretory duct, but, unlike Panagrellus, are not present around the median excretory duct. Anastomosis is not formed in the excretory ducts. In other respects the system of the species studied is similar to that of Panagrellus.The capitate tubules form a system of fine microtubules. Their ultrastructure and, particularly, their association with large numbers of mitochondria, is very reminiscent of structures thought to be concerned with an active transport role, related to ionic and osmoregulation in other phyla.The excretory system is almost certainly hypodermal in origin. Differences between the morphology and relations of the median duct of Enoplus (Narang, 1970), on the one hand, and that of the other forms studied suggest that these ducts may have different origins: the presence of separate nuclei in the lateral duct and gland portions of the system would be consistent with this view. It is considered that the two parts may have originated separately and have become joined during evolution. It is also shown that the excretory system of Ditylenchus cannot be derived either from an H-shaped system or from a primitive gland system.I wish to thank Professor C. Ellenby and Mr L. Smith for their helpful criticism.
Schistosoma mansoni: in vitrotransformation of cercariae into schistosomula
Authors: Gilbert B. , Da Rosa Marlene N. , Borojević R. , Pellegrino J. 
Published: June 2009

The transformation of cercariae ofSchistosoma mansoniinto schistosomula has previously been achieved by passage through membranes of biological origin. This transformation has now been effected in the absence of a membrane. Chemical stimulus for transformation results from contact with human or rat skin lipid and fractionation of the latter led to localization of the active component in a fraction containing phospholipids. The series of processes involved in transformation was subsequently found to be set in motion by the action of egg lecithin-water mixtures on an aqueous suspension of cercariae and yields of 90% of live schistosomula may be obtained reproducibly with crude egg lecithin-water in the ratio 1:50. The juvenile worms were found, by accepted criteria, to be identical to those produced by the normal penetration procedure. Purified lecithin does not produce the same stimulus and the effect of the physical state and of possible impurities present in crude egg lecithin is discussed.This work was supported by the Conselho Nacional de Pesquisas (Brazil), the Banco Nacional de Desenvolvimento Econâmico FUNTEC contracts nos. 99 and 110 (Brazil), U.S. Army Grants nos. DAHC-19-70-G-0017 (to B.G.) and DAHC-19-70-G-0070 (to J.P.) and by the FORGE Foundation. Contribution no. 18 from the Schistosomiasis Research Unit, Institute of Biological Sciences, Federal University of Minas Gerais, Brazil.
Biochemical and histochemical studies on the non-specific phosphomonoesterases ofFasciola giganticaCobbold 1855
Authors: Probert Allan J. , Goil Madan , Sharma R. K. 
Published: June 2009

Biochemical studies on the non-specific phosphomonoesterases ofFasciola hepaticahave shown the presence of acid phosphomonoesterase active at pH 4·6 and two forms of alkaline phosphomonoesterases active at pH 7·6 and pH 9·6 respectively. Histochemical studies have located acid phosphomonoesterase in the walls of the intestinal caeca and to a lesser extent in the tegument. Alkaline phosphomonoesterase was found to occur mainly in the excretory ducts and to a lesser degree in the uterine wall. Glycogen was mainly concentrated in the yolk glands, parenchyma, mature eggs and the non-muscular regions of both oral and ventral suckers.Dr A. J. Probert takes pleasure in recording the support of the British Council and the Indian University Grants Commission to enable him to study in India.
The role of the spleen in relation to natural and acquired immunity to infections ofBabesia rodhainiin the rat
Authors: Phillips R. S. 
Published: June 2009

In the system investigated the spleen was essential in most rats for the acquisition of immunity and its maintenance in the presence of the piroplasm.It is stressed that model immunological systems involving the role of the spleen do not simulate the complexity of a parasitic infection. The roles of the spleen as an antibody producer, and as a site of phagocytosis and haemopoiesis are discussed in relation to the control ofBabesia rodhainiby the rat. The possibility that the piroplasm may be able to undergo antigenic variation is considered.
Changes in the chemical composition ofHymenolepis diminuta(Cestoda:Cyclophyllidea) during prepatent development within the rat intestine
Authors: Mettrick D. F. , Cannon Christine E. 
Published: June 2009

The changes in the percentage chemical composition of both complete strobilae, and of the immature, mature, and gravid regions of the strobila ofHymenolepis diminutahave been studied during development of the worms from 5 to 16 days postinfection. The chemical components that have been evaluated are non-protein nitrogen, protein nitrogen, ribonucleic acid, deoxyribonucleic acid,lyo-glycogen,desmo-glycogen and total lipid.While the nitrogen, RNA and DNA fractions, expressed asμg/mg of worm dry weight, all decreased markedly with increasing worm age and size, the carbohydrate and lipid fractions increased over the same period of development.In worms up to 7 days old there is a high non-protein nitrogen value, high RNA and DNA fractions, thelyo-glycogen component of the total carbohydrate is very large, but the amount of carbohydrate expressed as a percentage of dry weight is low. These values are associated with the very high rate of metabolism of the young worms. From 7 to 16 days postinfection the rate of growth slows considerably, which is reflected in the corresponding decreases in the non-protein nitrogen, RNA and DNA fractions, and the increase in the total carbohydrate percentage.The changes in the chemical composition along a complete strobila complement the morphological evidence as the emphasis switches from segmentation to tissue differentiation and organ maturation.The changes with age in the percentage composition of the same region of the strobila show that neither the complete worms nor the different regions of a strobila are static in terms of their chemical components, but are changing systems which may be correlated with the ontogenetic development and migrational behaviour of the worms.
A field study of nematode parasite populations in the lactating ewe
Authors: O'Sullivan B. M. , Donald A. D. 
Published: June 2009

A typical postparturient rise of parasite egg output occurred in a group of lactating ewes. At parturition these animals carried few inhibited fourth-stage larvae and the rise was associated with a net increase in parasite populations, which did not occur in non-lactating ewes. Lactating ewes whose established parasite populations were effectively removed just prior to parturition showed a similar rise derived entirely from infection acquired during lactation, which was of much greater magnitude than that seen in similarly treated non-lactating animals. Circumstantial evidence of increased fecundity of T. colubriformis females in lactating ewes was also obtained.It was concluded that the postparturient rise of egg output may derive from an increase in adult parasite populations by an increased rate of establishment of newly ingested infective larvae which develop to the adult stage without inhibition, as well as by the resumption of development of previously inhibited fourth-stage larvae. In addition, both newly acquired and established adult female parasites may show increased fecundity.Ewes whose lambs were removed at birth or after a period of lactation showed a rapid fall in faecal egg counts associated with rejection of part of their existing worm burden and a pronounced increase in resistance to new infection.All of the differences observed between lactating and non-lactating ewes in the behaviour of their parasite populations were found to be qualitatively the same as those that have been frequently reported in susceptible and resistant non-reproductive sheep. The hypothesis is suggested, therefore, that the postparturient rise derives from a pronounced but temporary relaxation of immunological control of gastro-intestinal nematode infection associated with the endocrine status of the lactating ewe.
Cultivation of infective forms ofTrypanosoma congolensefrom trypanosomes in the proboscis ofGlossina morsitans
Authors: Gray M. A. , Cunningham I. , Gardiner P. R. , Taylor A. M. , Luckins A. G. 
Published: June 2009

SUMMARYTwo stocks ofTrypanosoma congolensewere established in culture at 28 °C using trypanosomes from the proboscides of infectiveGlossina morsitans. Successful primary cultures were initiated by placing an infected tsetse proboscis beside a bovine dermal collagen explant in Eagle's minimum essential medium supplemented with foetal calf serum. The trypanosomes multiplied rapidly in the medium and also gradually formed an adherent layer on the plastic surface of the culture vessel. Three primary cultures produced organisms infective for mice from 14, 20 and 35 days after initiation and thereafter continuously until days 76, 76 and 52 when they were discarded. Four attempts to initiate infective cultures using infected tsetse proboscides in medium without dermal explants were unsuccessful. When trypanosomes from primary cultures were placed in culture medium with proboscides from uninfected tsetse flies, the parasites multiplied, formed an adherent layer in the culture flasks and were seen in the proboscides within 24 h. A line of 1 stock was serially sub-passaged in this way 4 times during a period of 215 days. Infectivity titrations in mice indicated that primary and sub-passaged cultures each contained similar numbers of infective organisms. Another line of the same stock was also sub-passaged 4 times in medium alone over a period of 186 days. These sub-cultures again retained infectivity for mice, but titrations showed a decrease in infective organism production in the 4th sub-culture. Primary and sub-passaged cultures all included a variety of morphologically different developmental forms ofT. congolense, closely resembling those described in the labrum and hypopharynx ofGlossinaby previous workers. Short metacyclic-like trypanosomes and organisms with proteinaceous surface coats were present in infective cultures. Cultures were successfully re-established after cryopreservation at −196 °C and retained the ability to produce infective organisms.
The course of infection and growth of Moniliformis dubius (Acanthocephala) in the intermediate host Periplaneta americana
Authors: Lackie J. M. 
Published: June 2009

A quantitative study has been made of the relationship between Moniliformis dubius and Periplaneta americana.1. Eggs removed from the body cavity of the worm hatch at a higher rate after dessication and after a short period of time following removal.2. There is an exponential decline in the additional number of cystacanths recovered as the dose is increased linearly.3. Female cockroaches are more susceptible to high levels of infection than males.4. Direct injection into the haemocoele produces a similar recovery rate to that from oral infection.5. Previous infection does not seem to affect the success of a superimposed infection.6. Rates of development and growth are described.7. The effect of the parasite on the concentration of free amino acids in the haemolymph was found to be negligible.I would like to thank Miss S. Arnold and Mr D. Barnard for technical assistance, Mr E. Walters for help with statistical analysis, Dr D. W. T. Crompton for many helpful discussions and Dr P. J. Whitfield for reading this paper. This work has been carried out during the tenure of a Science Research Council Studentship.
Studies on molluscan schistosomiasis: An analysis of the development of the cercaria of Schistosoma mansoni
Authors: Cheng Thomas C. , Bier Jeffrey W. 
Published: June 2009

Development of cercariae within intramolluscan germinal sacs is recognized to be in seven stages; in brief, these stages are: 1, germinal cell; 2, naked cell aggregate; 3, germ ball prior to elongation; 4, elongating germ ball; 5, tail bud stage; 6, tail elongation stage; and 7, fully developed cercaria.Schistosoma mansoni cercariae at each of the developmental stages is described.The dimensions of both germinal and somatic cells comprising the bodies of developing S. mansoni cercariae decrease with maturation.The surfacial membrane of Stage 3 cercarial embryos is formed by a number of small somatic cells which migrate to the surface and coalesce.The chronologic and partially synchronized development of S. mansoni cercariae is presented.The body-tail ratio during S. mansoni cercarial development is presented.
The alleged alternation of sexual phases inKuhnia scombri, a monogenean ofScomber scombrus
Authors: Finlayson Janet E. 
Published: June 2009

SUMMARYIn 1945 Sproston stated that an alternation of sexual phases takes place inKuhnia scombri, a monogenean ofScomber scombrus, but an examination of egg-laying, the state of the sexual organs and the presence of sperms in this parasite at various times of the year have shown that there is no evidence for the existence of such a phenomenon. Sproston's observations are examined with particular reference to problems in measuring the length of the parasite and to the unreliability of using the presence or absence of eggs in the uterus as an index of femaleness.
Intraspecific and interspecific pairing of Haematoloechus medioplexus (Trematoda) and Echinostoma revolutum (Trematoda) adults in vitro, and observations on H. medioplexus lipophilic excretory–secretory products
Authors: Fried B. , Leiby D. A. 
Published: June 2009

SUMMARYIntraspecific pairing of Haematoloechus medioplexus and Echinostoma revolutum adults and interspecific pairing of H. medioplexus and E. revoltum adults were studied in vitro at 21 ± 1 °C and 30 ± 1 °C in Petri-dish cultures containing an agar substrate and a Locke's 1:1 solution overlay. Salinity and temperature tolerance tests showed that both species survived for 24 h in a Locke's 1:1 solution at 21 ± 1 °C and 30 ±1 °C. For behaviour studies, worms were placed 2 cm apart and then observed at various intervals from 5 min to 4 h. H. medioplexus and E. revolutum showed significant intraspecific pairing at 30±1 °C, whereas only H. medioplexus paired significantly at 21±1°C. Significant interspecific pairing of H. medioplexus and E. revolutum occurred at 21 ±1 °C and 30 ±1 °C. Thin-layer chromatographic analysis showed that H. medioplexus adults released mainly free sterol, along with traces of triacylglycerols and free fatty acids into a non-nutrient medium.
A comparison of membrane-bound enzymes of the isolated brush border plasma membranes of the cestodes Hymenolepis diminuta and H. microstoma
Authors: Pappas P. W. , Narcisi Elizabeth M. 
Published: June 2009

SUMMARYPreparations of isolated brush border plasma membrane of Hymenolepis diminuta and H. microstoma possess the following enzymatic activities: alkaline phosphohydrolase (E.C. 3.1.3.1); Type I phosphodiesterase (E.C. 3.1.4.1); ribonuclease (E.C. 3.1.4.22); adenosine triphosphatase (E.C. 3.6.1.3); and 5′-nucleotidase (E.C. 3.1.3.5). The following enzymatic activities could not be demonstrated in either membrane preparation: Type II phosphodiesterase (E.C. 3.1.4.18); cyclic adenosine-3′, 5′-monophosphate phosphodiesterase (E.C. 3.1.4.17); leucine aminopeptidase (E.C. 3.4.11.1); maltase (α-glucosidase; E.C. 3.2.1.20); and lactase (β-galactosidase; E.C. 3.2.1.23). These data generally agree with those of previous studies in which similar membrane-bound enzymes were demonstrated in intact (living) worms.
Studies on Eimeria grenieri in the guinea fowl (Numida meleagris)
Authors: Long P. L. , Millard B. J. 
Published: June 2009

SummaryEimeria grenieri was isolated from intensively reared guinea fowl in Britain. The oocysts had average dimensions of 21·09 × 15·48 μm and a small micropyle. Three generations of schizonts were found in the small intestine. The first mature schizonts were found in the upper intestine 30 h after inoculation. Second-generation schizonts were seen 48–80 h and third-generation schizonts were present 80–96 h after inoculation. These schizonts were found in the middle and lower small intestine. It was confirmed that gametogony of this species occurs only in the caeca. The pre-patent time was 112 h and the reproductive index from a dose of 6 × 102 oocysts was 8 × 104. Doses of between 1 × 104 and 1 × 106 caused severe depression of body weight gain. Immunity to re-infection developed rapidly. Sulphaquinoxaline at a dose of 0·04% in the drinking water given after inoculation was effective in reducing the pathogenic effects of the disease. Robenidine given in the food at a concentration of 16·5 ppm (50% of the recommended concentration for chickens) was effective in preventing disease caused by E. grenieri.The endogenous life-cycle of E. grenieri was completed in the chorioallantoic membrane of developing chicken embryos.
Desiccation survival of larval and abult stages of the plant parasitic nematodes,Ditylenchus dipsaciandD. myceliophagus
Authors: Perry R. N. 
Published: June 2009

The effect of different relative humidities on the survival of individual larvae and adults ofDitylenchus dispasciand D.myceliophagushas been examined; experiments were carried out at 5 and 18°C with D.myceliophagusand at 18°C with D.dipsaci. Survival of both species was enhanced when they were dried at high humidities and, for D.myceliophagus, by the lower temperature. The survival of all stages of D.myceliophaguswas poor. Generally it was expressed in minutes only; 4th-and 3rd-stage larvae, however, were marginally better at surviving drying than adults and much better than 2nd-stage larvae.Although the 4th-stage larva of D.dipsaciwas overwhelmingly superior to all other stages, the 3rd stage, and to a lesser extent, the adult of this species also showed remarkable powers of survival to desiccation. In general, survival of 4th-, 3rd- and 2nd-stage larvae could be expressed in weeks, days and minutes respectively; for adults, survival was expressed in hours at relative humidites under 50% but in days at higher relative humidites.The results are discussed in relation to the survival value of the aggregations formed by these species; the validity of the term ‘resistantstage’ as applied to the 4th-stage larva of D.dipsaciis assessed.
Intermittent egg release byAspiculuris tetrapterain mice
Authors: Phillipson R. F. 
Published: June 2009

In order to study egg release byAspiculuris tetrapteratotal faecal collections from infected mice were made every 1½ h throughout successive 24 h periods. This was done with the aid of a histokinette machine. The cage containing the mice was suspended from one of the arms of the machine and every 1½ h the cage was moved on by the machine to the next adjacent collecting dish. The faecal pellets passed were counted and then used for flotation egg counts.It was found that eggs were not released steadily and continuously and, in the case of the worms in an isolated mouse, egg output was clearly intermittent. Egg production did not appear to vary with the faecal production of the host in a consistent way but with two groups of 8 mice it was highest when faecal production was at its peak shortly before dawn. For the groups of 8 mice the concentration of eggs per faecal pellet was also highest at this time. In two experiments with an individual mouse, however, the egg counts fell to zero at dawn before the level of faecal production became reduced.It is suggested therefore that egg output by femaleA. tetrapteramay be stimulated by the altered physiological state of the host associated with feeding or general activity.
Monoamine oxidase in adult Hymenolepis diminuta (Cestoda)
Authors: Moreno M. Sanchez , Barrett J. 
Published: June 2009

SUMMARYA membrane-bound monoamine oxidase (EC 1.4.3.4) was demonstrated in homogenates of Hymenolepis diminuta. The enzyme oxidized a variety of biologically active amines (in decreasing order: dopamine, adrenaline, noradrenaline, tryptamine, tyramine, octopamine), there was, however, no activity with 5-hydroxytryptamine or benzylamine. No diamine oxidase (EC 1.4.3.6) could be detected in H. diminuta (using histamine, cadaverine or putrescine as substrates). The monoamine oxidase from H. diminuta was not inhibited by azide, hydroxylamine or semicarbazide, but was inhibited by cupferron, α-α dipyridyl and iodoacetamide, and by the specific monoamine oxidase inhibitors pargyline, nialamide and iproniazid. Several anthelmintics were also found to be inhibitors of monoamine oxidase. The possible roles of monoamine oxidase in H. diminuta are discussed.