bluuebunny/crossref_metadata_2025 huggingface dataset:
An association between schistosomes and contrapsin, a mouse serine protease inhibitor (serpin)
Authors: Modha J. , Parikh Vaishu , Gauldie J. , Doenhoff M. J.
Published: June 2009

An antigen in homogenates of adultSchistosoma mansoniworms grown in mice, and immunoprecipitated by polyspecific rabbit antiserum, has been identified as contrapsin, a mouse serine protease inhibitor (serpin). In the serum of some mice infected withS. mansonicontrapsin was found with altered immunoelectrophoretic characteristics when compared with contrapsin from uninfected mice.
Analysis of Opisthorchis viverrini antigens by immunoprecipitation and polyacrylamide gel electrophoresis
Authors: Wongratanacheewin S. , Chawengkirttikul R. , Bunnag D. , Sirisinha S.
Published: June 2009

Antigenicity of adult Opisthorchis viverrini, metacercariae and eggs was investigated by radio-immunoprecipitation and polyacrylamide gel electrophoresis using sera from patients with opisthorchiasis and from hamsters experimentally infected with 0. viverrini metacercariae. 125I-labelled aqueous somatic extract and in vitro metabolic products of adult worms, and the extracts of metacercariae and eggs were immunoprecipitated, electrophoresed and autoradiographed and major antigens were characterized. Although components with Mr of > 116, 89, 78 and 20 kD appeared to be specifically associated with the somatic extract of adult fluke, the 89 kD protein was the most prominent component found in the in vitro culture fluid of adult worms and the metacercarial extract. Hamsters, experimentally infected with 0. viverrini, also showed the presence of antibody reactive with the 89 kD component within 15 days of infection. The potential of this antigen in immunodiagnosis is discussed.
The importance of host age and sex to patterns of reinfection with Ascaris lumbricoides following mass anthelmintic treatment in a South Indian fishing community
Authors: Elkins D. B. , Haswell-Elkins Melissa , Anderson R. M.
Published: June 2009

Analysis of egg and worm counts of Ascaris recorded at various intervals following a mass anthelmintic treatment programme in a South Indian fishing community is presented. Three indices of infection in the community are compared, namely the prevalence and intensity of egg output (at 2, 6 and 11 months following treatment) and the number of worms expelled following an 11 month period of reinfection. Detailed examination of these measurements revealed significant associations with patient sex and age. The age-prevalence profile of Ascaris infection changed little over time (except immediately following treatment) with the peak prevalence found in the 5–9 year age group. Although 85% of both males and females harboured Ascaris initially, the prevalence following 11 months reinfection was decreased, due to a significantly lower proportion of males being reinfected. By the 11th month of reinfection, the age-intensity profiles of egg output were similar to those observed at initial treatment in the older age groups (10 years and above) and in male children (< 10 years). However, a dramatic increase in the egg output of female children, greatly exceeding the initial mean, was observed within a 6 month period of reinfection. The intensity of egg output did not accurately reflect the abundance of Ascaris recovered via drug-induced expulsion following an 11 month period of reinfection. Although the egg output attained preintervention levels, the average worm intensity reached only half the initial value. The trends in the sex- and age-intensity profiles were consistent at the two sampling dates and showed similar patterns to the egg output curves. The relevance of the results to helminth control and the monitoring of reinfection is discussed.
The population biology of the parasitic stages of Haemonchus contortus
Authors: Smith Gary
Published: June 2009

The population biology of the parasitic phase of the Haemonchus contortus life-cycle is discussed within the context of a mathematical model of those processes which regulate population density. Parasite death is assumed to be attributable to at least three processes: failure of the 3rd-stage larvae (L3) to exsheath following ingestion, failure to become established following exsheathment (immune exclusion), and mortality of 4th- and 5th-stage worms on the mucosal surface. The proportion of worms which avoid immune exclusion is a declining sigmoidal function of the duration of infection, at least under conditions of continual exposure to L3 larvae. Under the same conditions, the death rate of 4th- and 5thstage worms can be modelled as an increasing linear function of the host's experience of 3rd stage larvae. The model provides a good description of the worm burdens observed during the course of a long-term trickle infection experiment even though a priori arguments indicate that it would be an inadequate representation of events in the field.
Plasticity of gp63 gene organization in Leishmania (Viannia) braziliensis and Leishmania (Viannia) peruviana
Authors: Victoir K. , Dujardin J. C. , De Doncker S. , Barker D. C. , Arevalo J. , Hamers R. , Le Ray D.
Published: June 2009

The genomic organization of gp63 genes in 4 and 7 isolates of Leishmania braziliensis and L. peruviana, respectively was studied by RFLP analysis with 3 restriction enzymes (Bgl I, Sal I and Apa I). Our results showed a marked polymorphism among isolates. Some characters were specific to L. braziliensis or to L. peruviana, and others specific to the respective biogeographical populations of L. peruviana. The average minimum copy number of gp63 genes was found to be higher in L. braziliensis (71) than in L. peruviana (46), suggesting that deletion of gp63 genes might be partially involved in the size decrease of the chromosome bearing gp63 genes, observed between those 2 species (from 700 to 610 kb). Our results may suggest the existence of at least 2 arrays of heterologous gp63 repeats, varying in relative copy number between L. braziliensis and L. peruviana, and among isolates of the latter species. Rearrangement of the gp63 genes was observed during long-term in vitro maintenance of a reference strain of L. braziliensis. These observations document the existence of a dynamic gp63 gene organization in Leishmania of the braziliensis complex.
The evolution of tissue migration by parasitic nematode larvae
Authors: Read A. F. , Sharping A.
Published: June 2009

Migration by nematode larvae through the tissues of their mammalian hosts can cause considerable pathology, and yet the evolutionary factors responsible for this migratory behaviour are poorly understood. The behaviour is particularly paradoxical in genera such asAscarisandStrongylusin which larvae undergo extensive migrations which begin and end in the same location. The orthodox explanation for this apparently pointless behaviour is that a tissue phase is a developmental requirement following the evolutionary loss of skin penetration or intermediate hosts. Yet tissue migration is not always necessary for development, and navigation and survival in an array of different habitats must require costly biochemical and morphological adaptations. Migrating larvae also risk becoming lost or killed by the host. Natural selection should therefore remove such behaviour unless there are compensating benefits. Here we propose that migration is a selectively advantageous life-history strategy. We show that taxa exploiting tissue habitats during development are, on average, bigger than their closest relatives that develop wholly in the gastrointestinal tract. Time to reproduction is the same, indicating that worms with a tissue phase during development grow faster. This previously unsuspected association between juvenile habitat and size is independent of any effects of adult habitat, life-cycle, or host size, generation time or diet. Because fecundity is intimately linked with size in nematodes, this provides an explanation for the maintenance of tissue migration by natural selection, analogous to the pre-spawning migrations of salmon.
Characterization of the parasite-host cell interactions involved inTheileria parvasporozoite invasion of bovine lymphocytes
Authors: Shaw M. K.
Published: June 2009

Sporozoite invasion of bovine lymphocytes byTheileria parvais a pH-dependent process that occurs without the need forde novoprotein synthesis. The process was inhibited by RGD(S) peptides, fibronectin and, in the presence of serum, by antibodies reactive with fibronectin. Invasion was also blocked by a range of sulphated glycoconjugates, but treatment of lymphocytes with heparitinase did not inhibit entry. Enzymic modifications of the lymphocyte surface demonstrated that trypsin-insensitive glycoproteins containingO- andN-linked carbohydrates as well as phospholipase-sensitive molecules on the host cell surface were critical to sporozoite entry. Modification of the lymphocyte surface with NEM and DTT had only marginal effects on sporozoite binding but blocked parasite internalization. Invasion was also blocked by several antibodies which cross-reacted with sporozoite surface molecules. While only a few experimental conditions specifically blocked sporozoite binding, a wider range of reagents and treatments inhibited parasite entry. The reasons for this are discussed in terms of the nature of the zippering process that facilitates sporozoite internalization.
Density-dependent effects of Anguillicola crassus (Nematoda) within and on its copepod intermediate hosts
Authors: Ashworth S. T. , Kennedy C. R. , Blanc G.
Published: June 2009

Density-dependent effects of Anguillicola crassus larval infections in the copepod intermediate host were examined experimentally. Three species of copepods (Cyclops vicinus, C. viridis and C. fuscus) were subjected to a range of doses of larval A. crassus within infection arenas. Prevalence, intensity and parasite dispersion (variance: mean abundance) values increase and then approach an asymptote as infection dose increases. Infection parameters differ between species of copepod. Increasing temperature has a negative effect on the establishment of the parasite population within the intermediate host. Parasite-induced host mortality increases with dose. These mechanisms have the potential to regulate populations of A. crassus larvae within the copepod population and hence the whole suprapopulation.
Villus length influences habitat selection by Heligmosomoides polygyrus
Authors: Bansemir A. D. , Sukhdeo M. V. K.
Published: June 2009

Heligmosomoides polygyrus is a gastrointestinal nematode whose adult distribution is restricted to the duodenal region in the small intestine of the mouse. This study tests the hypothesis that the habitat of these parasitic worms is influenced by fixed (architectural) cues in the small intestine of the vertebrate host, and that H. polygyrus adults will select microhabitats containing the longest villi. H. polygyrus adults attach by coiling around the villi, and longer villi may provide greater attachment resources. In addition, these parasites feed on the epithelial cells covering the villi and thus longer villi may also provide more food resources. Using histological methods, this study identified a gradient of villus length in the small intestine of the mouse where the longest villi were found in the duodenum and shortest in the ileum Several non-surgical and surgical treatments were used to differentially alter the overall lengths of the villi. These treatments produced a significant negative correlation between villus length and worm distribution, with the worms selecting regions with the relatively longest villi in the small intestine. Attachment and feeding sites are crucial resources for this parasite, and these data suggest that villus length may be a reliable indicator of resource quality, and that decisions on habitat suitability by H. polygyrus adults may depend on this single, topological variable.
Lipid fractions in adult Schistosoma mansoni
Authors: Smith Thomas M. , Brooks Thomas J.
Published: June 2009

Total lipid from adult male and adult paired Schistosoma mansoni has been fractionated by thin-layer chromatography. Phospholipid, free sterol, and triglyceride were major components of both mixtures. A remarkably small amount of sterol ester was found in adult flukes considering the prevalence of this compound in mouse blood. Free fatty acids were found to be a minor component. Cholesterol was the major free sterol present.

The technical assistance of Mrs Katye Ross Summerlin is gratefully acknowledged.
The influence of dietary methionine on the amino acid pool ofHymenolepis diminutain the rat's intestine
Authors: Hopkins C. A.
Published: June 2009

The amount of [14C]methionine in the stomach, anterior and posterior intestine wall and lumen, blood and caecum of a rat, and in the anterior and posterior parts of the tapewormHymenolepis diminutain the intestine, was measured at intervals from 10 min to 10 h after feeding a meal of 2 g glucose and 37.5 mg methionine by stomach tube.

Nearly all the meal left the stomach within 5 h; the amount entering the tapeworm depended on the position of the worm. That part lying in the anterior half of the intestine was subjected to a rapid influx reaching a maximum concentration of at least 8 mM within 1–3 h after the meal was administered. The level in the worm then dropped to about 20 % of the peak level, although the stomach was still emptying and the level of methionine in the intestine wall was still rising. This was a stable state, and equal to the concentration in the posterior part of the worm which was reached 2 h after the rat was fed.

The reason why the anterior part of the worm should show a big influx and efflux is discussed and related to changes in concentration of methionine in the lumen. The lack of such a flux into and out of the worm further down the intestine is related to the host's homeostatic control of amino acid balance in the intestine.

The results prove that dietary imbalance of amino acids affect the amino acid pool in a tapeworm for about 3 h, if it lies in the anterior of the gut. A dietary regime is suggested which should produce a prolonged effect and thereby retard growth of the worm.

The weights of the parts of the worms found in the anterior and posterior half of the small intestine revealed an unexpected phenomenon; the majority of the tapeworm, by weight, lies in the anterior of the intestine for about 4 h following a meal, but in the posterior of the intestine after the stomach has emptied.

It is a great pleasure to thank Miss Gillian Moore and Miss Patricia Grant for technical assistance, and Shell International Petroleum Company, London, for financial support.
Observations on the nephridial system of the cestodeMoniezia expansa(Rud., 1805)
Authors: Howells R. E.
Published: June 2009

The nephridial system ofM. expansahas been studied using light and electron microscopy, and a number of histochemical techniques have been used on sections of the worm. The organization of the nephridial system and the fine structure of the flame cells and the nephridial ducts are described. Pores, which connect the nephridial lumen to the intercellular space of the connective tissue, exist at the junction of a flame cell and a nephridial duct. These pores may be considered nephrostomes and the system therefore is not protonephridial as defined by Hyman (1951).

The epithelium lining the nephridial ducts has a structure which suggests that it is metabolically active. It is postulated that the beating of the cilia of the flame cells draws fluid into the ducts via the nephrostomes, with absorption and/or secretion of solutes being carried out by the epithelial cells of the duct walls. The function of the nephridial system is discussed.

I am grateful to Professor James Brough for the provision of research facilities at the Department of Zoology, University College, Cardiff, andtoDrD. A. Erasmus for much helpful advice during the course of the work. I wish to thank Professors W. Peters and T. Wilson for critically reading the manuscript and Miss M. Williams and Mr T. Davies for expert technical assistance.

I also wish to thank the Veterinary Inspector and his staff at the Roath Abattoir, Cardiff, for their kind co-operation and assistance in obtaining material.

The work was carried out under the tenure of an S.R.C. research scholarship.
Natural and experimental hosts ofEchinococcus granulosusandE. multilocularis, with comments on the genetics of speciation in the genusEchinococcus
Authors: Smyth J. D. , Smyth Mildred M.
Published: June 2009

Within recent years, problems of host-parasite relationships have been receiving increasing attention from parasitologists. This is particularly true in the study of the cestodesEchinococcusspp., where predilection for different hosts—when considered with the morphology of the adult and the growth and development of the larva—seemed sufficiently significant to lead to the establishment of the two species,E. granulosusandE. multilocularis.Much experimental and field work has been carried out on a variety of vertebrate hosts and a number of new, naturally infected and laboratory hosts have been reported. A survey of intermediate and definitive hosts has been undertaken in this laboratory as part of a study to investigate whether factors of morphological, physiological or biochemical origin were concerned in host specificity. These data, together with some genetical considerations, form the basis of the present paper.
Observations on the scolex of Echinococcus granulosus, with special reference to the occurrence and cytochemistry of secretory cells in the rostellum
Authors: Smyth J. D.
Published: June 2009

1. The mode of attachment of Echinococcus granulosus to the dog intestine was examined.

2. In an attached worm, the scolex was found to penetrate deeply into the crypts of Lieberkühn, with the rostellum fully extended, the hooks penetrating the epithelium lightly and each sucker holding a ‘plug’ of mucous cells in its cavity.

3. The expansion of the rostellar tip was aided by a muscular disk, the rostellar pad, which probably assists attachment by forcing the hooks outwards.

4. The epithelium in the region of the suckers showed eosinophilic reactions which may indicate a mild host reaction.

5. The existence of a small group of spindle-shaped secretory cells which form a rostellar gland, lying immediately anterior to the rostellar pad, is reported. This gland was found to be the source of secretion droplets seen to be released in vitro from the scolex region.

6. The secretion droplets were found to be exceptionally labile and not preserved in the rostellar gland cells by routine fixation methods. Prolonged fixation (5–12 months) in formol (7% formaldehyde) gave excellent preservation but globules were fairly well preserved after 3 months fixation. Fixation in Baker's formol-calcium for 2 weeks followed by controlled chromation was also found to retain the secretion reasonably well but not as adequately as the prolonged fixation.

7. The secretion was found to be negative to the PAS, bromo-phenol blue (with Hg), and ninhydrin-Schiff reactions. The areas adjacent to the globules gave a protein reaction and the periphery of the globules appeared dark by phase contrast microscopy.

8. The secretion was weakly positive to performic acid-Schiff and gave strong reactions with Sudan Black after controlled chromation, both in frozen and wax sections. These results suggest that the secretion may be a liproprotein or a lipid-protein coacervate but it is recognized that confirmation by biochemical methods is desirable.

9. The possible immunological implications of these results are discussed.

This work was supported by the Australian Wool Research Committee and the U.S. Public Health Service Grant No. E. 4707–02. The technical assistance of Mrs A. L. Warrener and Mr A. B. Howkins is gratefully acknowledged.
The influence of the density of snails on the incidence of larval trematodes
Authors: Ewers W. H.
Published: June 2009

Samples of the snailVelacumantus australisfrom an area of 10 yards in diameter, were examined to determine if the incidence of larval trematodes varied with the density of the snails. The incidence in susceptible snails from areas where the density was less than 20 snails/sq. ft. was found to be significantly greater than in snails from areas where the density was higher than this. Further analysis showed that the variation in incidence, with density, was due almost entirely to the juvenile part of the population.
Antigenic similarity among culture forms of the ‘brucei’ group of trypanosomes
Authors: Seed J. Richard
Published: June 2009

Extensive cross-reactions have been found between cultural forms of trypanosomes of the ‘brucei’ group by the agglutination reaction. The antigen (or antigens) responsible for agglutination are apparently specific to the ‘brucei’ group of trypanosomes. These antigens are also quite stable to the presence of specific antiserum in contrast to the serotype of the blood trypanosomes which are known to be altered in the presence of specific antiserum.
Some new and little known cestodes from Australian elasmobranchs with a brief discussion on their possible use in problems of host taxonomy
Authors: Williams H. Harford
Published: June 2009

One diphyllidean and five tetraphyllidean cestodes from Australian elasmobranchs are described and figured.Echinobothrium heroniensissp.nov., fromHimantura granulata(Macleay, 1883) possesses two groups each of 42 apical hooks, eight rows each of 25 hooks on the cephalic peduncle and ten testes in each proglottid. InAnthobothrium sexorchidumsp.nov. fromT. lymna(Forskal, 1775) there are only six testes and the bothridium is irregularly divided into a number of shallow areolae while inRhinebothrium himanturisp.nov. fromHimantura granulatathere are 22 proglottids, 52 loculi and 19–20 testes. Comments are made on the taxonomy ofRhinebothriumsp.,Spiniloculus mavensisandYorkeria parva.The value of some helminths, especially cestodes from elasmobranchs, as an aid to the study of the taxonomy, biology and zoogeography of their hosts is briefly discussed with reference to some previous papers on this topic. Previous work on the cestodes of Australasian marine fishes is summarized briefly.
A dosing technique and the effects of sub-lethal doses of Nosema fumiferanae (Microsporida) on its host the spruce budworm, Choristoneura fumiferana
Authors: Wilson G. G.
Published: June 2009

Various dosages of the microsporidian parasite, Nosema fumiferanae were fed to 12-day-old larvae of Choristoneura fumiferana using a previously undescribed bioassay capsule. A spore dose of 3 × 104 resulted in 92% infection and a significant reduction in pupal weights, adult female longevity and a mean spore concentration of 1·5 × 107/living adult. Significant mortality (68%, combined larvae and pupae) did not occur until larvae ingested 3 × 107 spores; this dose produced a mean of 1·8 × 107 spores in dead larvae and 3·6 × 107 and 4·6 × 107 spores in dead male and female pupae respectively.
The morphology and life-cycle of the oviparousOögyrodactylus farlowellaegen. et sp.nov. (Monogenea, Gyrodactylidea)
Authors: Harris P. D.
Published: June 2009

Oögyrodactylus farlowellaegen. et sp.nov., an oviparous monogenean, is described from the skin and fins ofFarlowella amazonum, a South American loricarid catfish. The Oögyrodactylidae fam.nov., containingO. farlowellae and Phanerothecium caballeroiKritsky and Thatcher, 1977, is placed with the Gyrodactylidae in the Gyrodactylidea. Although oviparous, the Oögyrodactylids are closely related to the viviparous gyrodactylids. Both families share a combination of characters, including haptor morphology, articulated marginal hooks and spike sensilla, which is not seen in other monogeneans.O. farlowellaeis similar to a hypothetical ancestor of the gyrodactylids and shows that the family arose from monopisthocotylean rather than polyopisthocotylean stock. There is a close resemblance between the reproductive system of the immatureOögyrodactylusand that of the matureGyrodactylus, suggesting that progenesis, involving the precocious maturation of oocytes, may have been important in the evolution of the viviparous genera.O. farlowellaeretains eggs individually in the ootype until embryonation is comparatively advanced. After oviposition the eggs adhere to the substrate and hatch to give a crawling, unciliated larva. These are adaptations to a host which inhabits fast-flowing streams, where the eggs and infective larvae are exposed to a constant, uni-directional water current. The life-cycle (egg to adult) is completed in 11–13 days at 27 °C.
Some new pilicolous mites from South African mammals
Authors: Lawrence R. F.
Published: June 2009

In March 1945 the writer had the opportunity of examining a young specimen of the South African lemur, Otolemur crassicaudatus garnetti, formerly known as Galago garnetti (Ogilby), sent into the Museum by Mr N. A. W. Macpherson from Cato Ridge near Pietermaritzburg, Natal. Fourteen Cheyletid mites were found in the fur on the back of the animal, some of them fairly active and none attached to the hairs of the body. In August 1946 a further number of mites belonging to the same family was taken from the fur of the slender mongoose, Myonax cauui punctulatus (Gray) captured at Mooi River. Finally, a number of larval Trombidiform mites were collected from the skin of a golden mole, Amblysomus hottentotus longiceps (Broom), donated by Mr R. S. Crass from Curry's Post near Pietermaritzburg.
The respiratory horns of Psychoda pupae (Diptera: Psychodidae)
Authors: Satchell G. H.
Published: June 2009

1. The respiratory horn of Psychoda severini Tonn. subsp. parthenogenetica Tonn. is described. Within the tubular horn lies the felt chamber, which meets the horn wall at a number of thin circular regions, the pits, and communicates, through the annulated base of the horn, with the tracheal extension. This has a characteristic retiform thickening and is continuous, at the lower end, with the spiracular chamber, from which a trachea runs to the prothoracic spiracle of the imago.

2. At the upper end of the tracheal extension lies the closing mechanism consisting of a lever, and a muscle surrounded by a cuticular sheath. It is suggested that the mechanism functions by compressing the tracheal extension, and that the sheath serves to protect the muscle from the action of the moulting fluid.

3. The respiratory horns of fourteen of the British species of Psychoda are described, and it is shown that Ps. spreta Tonn., Ps. albipennis Zett. and Ps. trinodulosa Tonn. are like Ps. severini in possessing long lateral tubes in at least the basal half of the horn, whereas Ps. alternata Say, Ps. surcoufi Tonn., Ps. cinerea Banks, Ps. gemina Eaton, Ps. lobata Tonn., Ps. grisescens Tonn. and Ps. setigera Tonn. have only short lateral tubes. The two species Ps. phalaenoides L. subsp. elongata Tonn. and Ps. crassipenis Tonn. are alike in having a two-branched felt chamber, and Ps. brevicornis Tonn. has a flat triangular horn with a three-branched felt chamber and a cluster of air-containing tubes at each corner.

4. An account is given of the development of the respiratory horn of Ps. alternata Say. The horn arises as an outgrowth from the larval prothoracic imaginal disk, and the felt chamber forms by an invagination of its posterior wall. The tracheal extension arises as an invagination of the disk and subsequently acquires a connexion to the felt chamber.

5. The development is compared with that of Chaoborus plumicornis, and it is concluded that Weismann's theory of the origin of the horn from two distinct cell layers is not applicable to Psychoda.

6. The various terms that have been applied to the respiratory horn are discussed, and the conclusion is reached that though none of them is satisfactory, it is premature to devise a new scheme of nomenclature.

Grateful acknowledgements are due to Dr Ll. Lloyd for his help and advice in the course of this work. Some of the material was collected whilst the writer was in receipt of a grant from the Department of Scientific and Industrial Research, to whom acknowledgements are also due.
A list of the trichostrongylid lungworms (Phylum Nematoda) and a key to the six genera
Authors: Dougherty Ellsworth C.
Published: June 2009

In recent papers I have given, in relatively compact form, lists of the genera and species of metastrongylid lungworms; these publications are in turn summarized in a paper which follows (Dougherty, 1948). However, the trichostrongylid lungworms, constituting the subfamily Skrjabingylinae Skriabin, 1933, have not been completely treated, although in a recent work (Dougherty, 1945), in which certain lungworms were formally transferred from the Metastrongylidae to the Trichostrongylidae, the Skrjabingylin genera were listed without critical appraisal, and in the same paper the genus Crenosoma Molin, 1861, was reviewed in detail; subsequently the genus Dictyocaulus Railliet & Henry, 1907, has also been reviewed (by Dougherty, 1946).
Studies on the nematodes parasitic in the lungs of Felidae in Palestine
Authors: Gerichter Ch. B.
Published: June 2009

Three species of lung nematodes have been found in Felidae in Palestine: Aelurostrongylus abstrusus, Troglostrongylus brevior n.sp. and Anafilaroides rostratus n.g., n.sp. The life histories of all these species have been studied. Their larvae develop in terrestrial molluscs. Some new observations on the factors influencing the development of the larvae of Aelurostrongylus abstrusus are described. The whole developmental cycle of Troglostrongylus brevior has been experimentally reproduced. Initial stages of the development of the larva of Anafilaroides rostratus in molluscs have been observed. The taxonomic position of the genera Aelurostrongylus and Troglostrongylus is discussed and their protostrongyline character is demonstrated.
Notes on the life history of a parasitic copepod, Lernaea chackoensis
Authors: Gnanamuthu C. P.
Published: June 2009

1. The nauplius, the metanauplius and the first copepodid larva, of Lernaea chackoensis were reared in vitro and are described.

2. The four copepodid larvae obtained by artificial infection of Barbus stigma and Oryzias rubristigma are described.

3. The young females infesting the adult host fishes are described, noting the changes which take place after the copulation of the female larva.

4. The accelerated development of this tropica form and the need for a temporary host to complete the life cycle are discussed.
Immunity and metabolic rate: the course of notoedric scabies in rats with different metabolic rates
Authors: Leech F. B. , Spence T.
Published: June 2009

1. Two experiments are described investigating the effects of level of metabolism on (a) resistance to, and (b) recovery from, Notoedric scabies of rats. The progress and severity of the disease was measured by weekly counts of the number of lesions; the metabolic rate in some rats was raised by administration of iodinated casein and in others was depressed by methyl thiouracil.

2. In normal rats, the initial severe phase of the disease was followed by a partial recovery with survival of a smaller population of parasites.

3. This recovery process in established infestations was hastened by elevation and retarded by depression of the metabolic rate.

4. Resistance to the development of severe disease was enhanced by elevation and reduced by depression of the basal metabolic rate.

5. The level of the residual infestation, after the severe phase of the disease had passed, was also affected by the treatment, being decreased by the higher but increased by the lower metabolic rate.
The food habits ofEntamoeba histolyticain its commensal phase
Authors: Hoare Cecil A.
Published: June 2009

1. After a general consideration of the host-parasite relations betweenE. histolyticaand man, a case is made for the recognition of a commensal phase in the life history of this amoeba.

2. This view is supported by observations on the food habits ofE. histolyticain chronic cases and carriers of human amoebiasis.

3. From these observations it is evident that from 30 to 100% of trophic amoebae in such cases have ingested bacteria derived from the contents of the large bowel.
On the systematic position of the genus Deropristis, of Dihemistephanus sturionis little, 1930, and of a new digenetic trematode from a sturgeon
Authors: Cable R. M.
Published: June 2009

Pristotrema manteri n.g., n.sp. is described from the spiral valve of the shovel-nosed sturgeon, Scaphirhynchus platorhynchus (Rafinesque), in the Wabash River, Indiana, U.S.A.

A new genus, Pristicola, is erected for Dihemistephanus Little, 1930, nec Looss, 1901, with Pristicola sturionis (Little) as the type and only species.

The subfamily Deropristiinae Cable & Hunninen, 1942, is re-defined to receive the genera Pristotrema and Pristicola as well as the type genus, Deropristis.

The uncertain family position of the Deropristiinae is discussed without removing it from the Lepocreadiidae, although the independent status of that family may be questioned in the light of recent work.
Zinc transporter-2 (ZnT2) variants are localized to distinct subcellular compartments and functionally transport zinc
Authors: Lopez Veronica , Kelleher Shannon L.
Published: June 2009

ZnT2 (zinc transporter-2) expression is restricted to tissues with unique zinc requirements such as mammary and prostate glands. We previously determined that ZnT2 plays a major role in zinc export from mammary glands, as women with a mutation in the gene encoding ZnT2 (SLC30A2) had an ∼75% reduction in milk zinc concentration. Two distinct human ZnT2 isoforms (∼42 and 35 kDa) are predicted to result from alternative splicing of SLC30A2. We examined the localization and function of each ZnT2 isoform, in cells generated to express ZnT2–HA (haemagglutinin) fusion proteins. The 42 kDa isoform was localized primarily to the endosomal/secretory compartment and overexpression resulted in increased zinc vesicularization. In contrast, the 35 kDa isoform is associated with the plasma membrane. Importantly, zinc transport was higher in cells over-expressing each isoform, indicating that both proteins are functional. Endogenous expression of the secretory vesicle-associated ZnT2 isoform predominates in mammary cells and expression is higher in secreting cells, whereas the smaller isoform plays a minor role in zinc export, directly reflecting the secretory function of the mammary gland. Together our data shed further light on the complex integration of cellular zinc transport mechanisms, which may be facilitated by multiple isoforms of specific zinc transporters with unique cellular functions.
Epidermal growth factor stimulates translocation of the class II phosphoinositide 3-kinase PI3K-C2β to the nucleus
Authors: Banfic Hrvoje , Visnjic Dora , Mise Nikica , Balakrishnan Sanjeevi , Deplano Simona , Korchev Yuri E. , Domin Jan
Published: June 2009

Although the class II phosphoinositide 3-kinase enzymes PI3K-C2α and PI3K-C2β act acutely downstream of cell surface receptors they have also been localized to nuclei in mammalian cells. As with the class I PI3K enzymes, the relationship between the pools of enzyme present in cytoplasm and nuclei remains poorly understood. In this study we test the hypothesis that PI3K-C2β translocates to nuclei in response to growth factor stimulation. Fractionating homogenates of quiescent cells revealed that less than 5% of total PI3K-C2β resides in nuclei. Stimulation with epidermal growth factor sequentially increased levels of this enzyme, firstly in the cytosol and secondly in the nuclei. Using detergent-treated nuclei, we showed that PI3K-C2β co-localized with lamin A/C in the nuclear matrix. This was confirmed biochemically, and a phosphoinositide kinase assay showed a statistically significant increase in nuclear PI3K-C2β levels and lipid kinase activity following epidermal growth factor stimulation. C-terminal deletion and point mutations of PI3K-C2β demonstrated that epidermal growth factor-driven translocation to the nucleus is dependent on a sequence of basic amino acid residues (KxKxK) that form a nuclear localization motif within the C-terminal C2 domain. Furthermore, when this sequence was expressed as an EGFP (enhanced green fluorescent protein) fusion protein, it translocated fluorescence into nuclei with an efficiency dependent upon copy number. These data demonstrate that epidermal growth factor stimulates the appearance of PI3K-C2β in nuclei. Further, this effect is dependent on a nuclear localization signal present within the C-terminal C2 domain, indicating its bimodal function regulating phospholipid binding and shuttling PI3K-C2β into the nucleus.
Altered tumor formation and evolutionary selection of genetic variants in the human MDM4 oncogene
Authors: Atwal Gurinder Singh , Kirchhoff Tomas , Bond Elisabeth E. , Montagna Marco , Menin Chiara , Bertorelle Roberta , Scaini Maria Chiara , Bartel Frank , Böhnke Anja , Pempe Christina , Gradhand Elise , Hauptmann Steffen , Offit Kenneth , Levine Arnold J. , Bond Gareth L.
Published: June 2009

A large body of evidence strongly suggests that the p53 tumor suppressor pathway is central in reducing cancer frequency in vertebrates. The protein product of the haploinsufficient mouse double minute 2 (MDM2) oncogene binds to and inhibits the p53 protein. Recent studies of human genetic variants in p53 and MDM2 have shown that single nucleotide polymorphisms (SNPs) can affect p53 signaling, confer cancer risk, and suggest that the pathway is under evolutionary selective pressure (
1

–
4
). In this report, we analyze the haplotype structure of MDM4, a structural homolog of MDM2, in several different human populations. Unusual patterns of linkage disequilibrium (LD) in the haplotype distribution of MDM4 indicate the presence of candidate SNPs that may also modify the efficacy of the p53 pathway. Association studies in 5 different patient populations reveal that these SNPs in MDM4 confer an increased risk for, or early onset of, human breast and ovarian cancers in Ashkenazi Jewish and European cohorts, respectively. This report not only implicates MDM4 as a key regulator of tumorigenesis in the human breast and ovary, but also exploits for the first time evolutionary driven linkage disequilibrium as a means to select SNPs of p53 pathway genes that might be clinically relevant.
The encoding of alternatives in multiple-choice decision making
Authors: Albantakis Larissa , Deco Gustavo
Published: June 2009

During the last decades, research on binary decision making elucidated some of the basic neural mechanisms underlying the decision-making process. Recently, the focus of experimental as well as modeling studies began to shift from simple binary choices to decision making with multiple alternatives. In this article, we address the question how different numbers of choice alternatives might be handled and encoded in the brain. We present a minimal, biophysically realistic spiking neuron model for decision making with multiple alternatives. Our model accounts for the relevant aspects of recent experimental data of a random-dot motion-discrimination task on both the cellular and behavioral level. Notably, all network parameters and inputs in our network are independent of the number of possible alternatives used in the tested experimental paradigms (2 and 4 alternatives and 2 alternatives with an angular separation of 90°). This avoids the use of extra top-down regulation mechanisms to adapt the network to the number of choices. Furthermore, we show that increasing the number of neurons encoding each choice alternative is positively related to the network's capacity of choice-number-independent decision making. Consequently, our results suggest a physiological advantage of a pooled, multineuron representation of choice alternatives.
Detecting SNPs and estimating allele frequencies in clonal bacterial populations by sequencing pooled DNA
Authors: Holt Kathryn E. , Teo Yik Y. , Li Heng , Nair Satheesh , Dougan Gordon , Wain John , Parkhill Julian
Published: June 2009

Summary: Here, we present a method for estimating the frequencies of SNP alleles present within pooled samples of DNA using high-throughput short-read sequencing. The method was tested on real data from six strains of the highly monomorphic pathogen Salmonella Paratyphi A, sequenced individually and in a pool. A variety of read mapping and quality-weighting procedures were tested to determine the optimal parameters, which afforded ≥80% sensitivity of SNP detection and strong correlation with true SNP frequency at poolwide read depth of 40×, declining only slightly at read depths 20–40×.

Availability: The method was implemented in Perl and relies on the opensource software Maq for read mapping and SNP calling. The Perl script is freely available from ftp://ftp.sanger.ac.uk/pub/pathogens/pools/.

Contact:  kh2@sanger.ac.uk

Supplementary information:  Supplementary data are available at Bioinformatics online.
Measuring and modelling Pacific herring spawning-site fidelity and dispersal using tag-recovery dispersal curves
Authors: Flostrand Linnea A. , Schweigert Jacob F. , Daniel Kristen S. , Cleary Jaclyn S.
Published: June 2009

Flostrand, L. A., Schweigert, J. F., Daniel, K. S., and Cleary, J. S. 2009. Measuring and modelling Pacific herring spawning-site fidelity and dispersal using tag-recovery dispersal curves. – ICES Journal of Marine Science, 66: 1754–1761. An approach of relating Pacific herring (Clupea pallasi) tag-recovery data to dispersal distances is presented. Observations from coded wire tag sampling (1999–2006) were used to represent adult herring interannual spawning patterns on the British Columbia coast. Six datasets were applied, differing by number of years-at-liberty (1, 2, or 3) and gear type of recapture (purse-seine or gillnet). In total, 227 tag-recovery samples, consisting of 5687 tag recoveries, were used. Distances were approximated to the shortest paths through water between the release and recapture sites. Recovery rate and distance relationships suggest that exponential models fit the data reasonably well, with average rates of change in recovery rates (slopes) varying from approximately −0.009 to −0.005. A combined slope estimate of −0.007 is similar to four of the six estimates. Using these models, the intensity of movement among five stock-assessment regions was estimated by applying distances relative to their centres. Fidelity estimates range from 53 to 90% across all models and regions, which is consistent with previous findings and premises that influence resource management. Interpretation and application of the modelling exercise are discussed in terms of previous and future work.
Molecular cloning and sequencing of a pectinesterase gene from Pseudomonas solanacearum
Authors: Spök Armin , Stubenrauch Gerhard , Schörgendorfer Kurt , Schwab Helmut
Published: June 2009

Summary: Two pectinesterase-positive Escherichia coli clones, differing in expression levels, were isolated from a genomic library of Pseudomonas solanacearum. Both clones contained a common DNA fragment which included the pectinesterase-encoding region. The different expression levels found with the two clones could be ascribed to different positioning of the pectinesterase gene with respect to a vector promoter. Restriction analysis, subcloning, and further exonuclease deletion mapping revealed that the genetic information for pectinesterase was located within a 1·3 kb fragment. A protein of 41 to 42 kDa was expressed from this fragment. Nucleotide sequence analysis of the respective region disclosed an open reading frame of 1188 bp. The deduced polypeptide had a calculated molecular mass of 41 004 Da, which is consistent with the determined size of the pectinesterase protein. The predicted amino acid sequence showed significant homology to pectinesterases from Erwinia chrysanthemi and tomato. In cultures of E. coli clones up to 30% of total pectinesterase activity was transported into the medium. However, no significant pectinesterase activity could be detected in the periplasm.
Root surface colonization of non-cereal crop plants by pleomorphic Azospirillum brasilense Cd
Authors: Bashan Yoav , Levanony Hanna , Whitmoyer Robert E.
Published: June 2009

Summary: Root surface colonization byAzospirillum brasilenseCd of tomato, pepper and cotton plants under normal growth conditions and soybean plants under normal and water-stress conditions was monitored by scanning electron microscopy and bacterial counts.A. brasilenseCd was capable of efficiently colonizing the elongation and root-hair zones of all four plant species tested. In these zones, the bacteria mainly colonized the root surface (tomato, soybean), root-hairs (pepper), or both (cotton), by single cells (tomato, soybean), micro-aggregates (pepper), or a combination of the two (cotton). All inoculated plants demonstrated (i) larger amounts of mucigel-like substance on the root surface than non-inoculated plants and (ii) fibrillar material which anchored the bacterial cells to the root surface and established connections between cells within bacterial aggregates. On non-water-stressed soybean plants, mostA. brasilenseCd cells in the rhizosphere occurred as vibroid forms whereas those on water-stressed plants (wilting) were cyst-like. A lower rhizosphere bacterial population was observed on water-stressed plants. When water-stress conditions were eliminated, the bacterial cells reverted to the vibroid form and a concomitant increase in the bacterial population was observed. It is suggested that cyst-like formation is a natural response forA. brasilenseCd in the rhizosphere of water-stressed plants.
Comparison of peptidase, glycosidase and esterase activities of oral and non-oral Treponema species
Authors: Mikx F. H. M.
Published: June 2009

Summary: The enzyme profiles of 20 oral and non-oral Treponema strains were investigated using an API ZYM Complete Research kit. The test included 10 2-naphthyl derivatives of fatty acids, 20 p-nitrophenol derivatives of carbohydrates and 60 2-naphthylamide derivatives of amino acids and peptides. The oral Treponema species investigated were T. denticola, T. vincentii and T. pectinovorum. The non-oral species examined were T. phagedenis, T. hyodysenteriae and intestinal spirochaetes of human and chicken origin. Esterase activities on C5 to C10 fatty acids were common among different Treponema species. Glycosidase activities were infrequently observed in T. vincentii, T. pectinovorum and T. phagedenis Reiter strain. Arabinosidase, lactosidase and xylosidase activity was observed in the T. hyodysenteriae strains but α-L-fucosidase activity was found only in T. denticola and T. phagedenis. More exo- and endo-peptidase activities were found in T. denticola than in other species. The enteropathogenic T. hyodysenteriae isolates had a very low proteolytic profile. Dipeptidyl prolyl amidase activity was observed in all species except in the T. phagedenis Reiter strain and the avian intestinal spirochaetes. The enzyme profiles did not discriminate between oral and non-oral Treponema species.