bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors influencing development of free-living generations of Strongyloides stercoralis
Authors: Shiwaku K. , Chigusa Y. , Kadosaka T. , Kaneko K. 
Published: June 2009

SUMMARYThe effects of duration of infection and of temperature and nourishment in cultures on development of free-living generations of Strongyloides stercoralis were studied quantitatively. Rhabditiform larvae, 228–353 μm long, were collected from infected dogs with or without prednisolone treatment using the Baermann apparatus. Cultures were carried out by the filter paper test-tube method under the following conditions: incubation temperature 15–40°C and faecal dilution 1:0–1:16. Rhabditiform larvae developed predominantly to free-living females at incubation temperatures of 15–30°C and low faecal dilutions, but filariform larvae appeared mainly under extreme conditions such as high temperature. Recovery rates of filariform larvae were inversely related to those of females. It was remarkable that high temperature, but not low faecal dilution, affected development of filariform larvae. Although the appearance of free-living males was constant in various environmental conditions, the present study indicated an increase in free-living males with the duration of infection. Thus, it seems that free-living males are already fixed as male in the egg stage, and potential female rhabditiform larvae differentiate into free-living females or filariform larvae depending on environmental factors. There is no marked difference in the development of rhabditiform larvae into filariform larvae in either the immunosuppressed dog or the intact dog.
Pomphorhynchus laevis (Acanthocephala): elevation of haemolymph protein concentrations in the intermediate host, Gammarus pulex (Crustacea: Amphipoda)
Authors: Bentley C. R. , Hurd H. 
Published: June 2009

SUMMARYComparisons were made between the protein concentrations and protein profiles of uninfected Gammarus pulex and those infected with cystacanths of Pomphorhynchus laevis. Comparisons of the extractable haemolymph volumes from uninfected and infected G. pulex, when related to host tissue weight, showed that there was no difference in the host tissue/haemolymph volume ratio between infected and uninfected individuals. SDS-PAGE of haemolymph samples resolved 36 bands of protein, the major components being band 6(19 kDa) and 21(33 kDa). Densitometric analysis of haemolymph samples showed that infected gammarids had total protein concentrations elevated by 84%. The (88 kDa) subunit was identified as the monomer of the respiratory protein haemocyanin. This band was significantly elevated in infected individuals (one-way ANOVA P < 0.001); increasing from 30 to 45% of the total haemolymph proteins.
Histochemical observations on carbohydrates, lipids and enzymes in digenean parasites and host tissues of Bithynia tentaculata
Authors: Reader Trevor A. J. 
Published: June 2009

Active digenean larvae in Bithynia tentaculata were found to utilize both host carbohydrates and lipids, and these were incorporated into the bodies of developing cercariae. Although rediae obtain most of their nutrients by direct ingestion, a decrease in the glycogen and neutral fat content of intact digestive gland cells of snails infected with rediae suggests that these larvae may also absorb nutrients through their body walls, like sporocysts. In sporocyst infections, host glycogen is believed to be hydrolysed to glucose and other monosaccharides by the host's own enzymes, possibly phosphatases, which have been stimulated to greater activity by the parasites. These simple sugars, due to their small size, can then be absorbed through the sporocyst body wall. Similarly, host fats are probably degraded to fatty acids, possibly by a parasite-secreted lipase, prior to absorption by the parasites. Encysted metacercariae do not appear to feed, but they do have severe pressure effects which disrupt some of the digestive gland tubules. Such tubules show an increase in their neutral fat content and a decrease in phosphatase activity. Aminopeptidase enzymes secreted by active digenean larvae may be responsible for some lysis of host cells, and may also be involved in the breakdown of lymph proteins to amino acids.I am indebted to Dr F. R. Stranack for her supervision and guidance throughout this investigation, and to Dr G. Charles and Dr T. Jenkins for their continued help and advice. This study was carried out during the tenure of a research assistantship awarded by the governors of Portsmouth Polytechnic.
NO nerves in a tapeworm. NADPH-diaphorase histochemistry in adultHymenolepis diminuta
Authors: Gustafsson M. K. S. , Lindholm A. M. , Terenina N. B. , Reuter M. 
Published: June 2009

SUMMARYThe free radical nitric oxide (NO), which is synthesized by nitric oxide synthase (NOS), has recently been discovered to function as a neuronal messenger. The presence of NOS was detected in the nervous system of adultHymenolepis diminutawith NADPH-diaphorase (NADPH-d) histochemistry. The NADPH-d histochemical reaction is regarded as a selective marker for NOS in neuronal tissue. NADPH-d staining was observed in nerve fibres in the main and minor nerve cords and the transverse ring commissures, and in cell bodies in the brain commissure, along the main nerve cords, in the suckers and the rostellar sac. NADPH-d staining was also observed in the wall of the internal seminal vesicle and the genital atrium. The pattern of NADPH-d staining was compared with that of the 5-HT immunoreactive nervous elements. The NADPH-d staining reaction and the 5-HT immunoreactivity occur in separate sets of neurons. This is the first time the NADPH-d reaction has been demonstrated in the nervous system of a flatworm, indicating that NOS is present and that NO can be produced at this level of evolution.
Hepatic fibrosis and gene expression changes induced by praziquantel treatment during immune modulation ofSchistosoma japonicuminfection
Authors: Kresina T. F. , He Qing , Degli Esposti S. , Zern M. A. 
Published: June 2009

SUMMARYIn the present study fibrogenic gene expression was determined in murineSchistosoma japonicuminfection during the progression of immune modulation of infection and following chemotherapy during the course of immune modulation. Histomorphometric analysis of granuloma size and collagen deposition revealed peak granuloma size in acute infection (5 weeks) and peak hepatic collagen content at 16 weeks of infection. Peak Type I collagen gene expression was concomitant with TGF-β1 gene expression at 8–11 weeks. Chemotherapy during either acute (9 weeks) or chronic (24, 28 weeks) infection resulted in increased collagen deposition and increased gene expression of Type I collagen and TGF-β1. However, chemotherapy at 14–16 weeks resulted in decreased levels of TGF-β1 gene expression and essentially minimal change in Type I collagen deposition and gene expression. These data indicate that chemotherapy of schistosomiasis japonica does not reverse hepatic fibrogenesis when administered in acute infection – when granuloma size is maximal – or in chronic infection. However, a beneficial effect on hepatic fibrogenesis is seen when chemotherapy is administered at 14–16 weeks post-infection, a time of decreasing granuloma size and maximal hepatic collagen content. Thus the ability to reverse schistosomal-induced hepatic fibrogenesis by chemotherapy may depend on disease stage.
A comparison between the helminth burdens of male and female brown trout, Salmo trutta L., from a natural population in the River Teify, West Wales
Authors: Thomas J. D. 
Published: June 2009

Nine hundred and five brown trout were collected from the River Teify, West Wales, over a period of 12 months and their helminth infestations are considered in relation to the age and sex of the host and season.Only one statistically significant difference could be detected between levels of infestation in male and female trout of 1 and 2 years of age.When trout of 3 years of age and over were spawning or recovering from the effects of spawning there is a tendency for sexually mature females to be more heavily infested with some parasites than the males. During the season of growth and maturation of the gonads this trend was reversed or became less marked. In the case of fish that were not spent or spawning the statistically significant differences showed the males to be more heavily infested than the females.The possible reasons for these variations are discussed with particular reference to the roles of ‘physiological’ and ‘behavioural’ or ecological resistance'.
Immunolocalization and characterization of the low molecular weight antigen (4–5 kDa) ofToxoplasma gondiithat elicits an early IgM response upon primary infection
Authors: Tomavo S. , Couvreur G. , Leriche M. A. , Sadak A. , Achbarou A. , Fortier B. , Dubremetz F. 
Published: June 2009

SUMMARYA striking feature of toxoplasmic seroconversion is the prominent and early IgM response to a low molecular weight antigen of 4–5 kDa. Two different monoclonal antibodies directed against the 4–5 kDa antigen have been generated and used to characterize this molecule. Using these monoclonal antibodies, we could demonstrate the surface localization of the lowMrantigen by immunofluorescence and immuno-electron microscopy assays. By immunoblotting, we observed that one of the monoclonal antibodies was unable to recognize the 4–5 kDa antigen in tachyzoites propagated in cell culture, indicating an epitope variability betweenToxoplasma gondiitachyzoites grownin vivoandin vitro. We discuss the implications of this latter finding in the design of diagnostic reagents.
Host finding behaviour as a predictor of foraging strategy in entomopathogenic nematodes
Authors: Grewal P. S. , Lewis E. E. , Gaugler R. , Campbell J. F. 
Published: June 2009

SUMMARYForaging strategies of eight species of entomopathogenic nematodes were predicted from their response to host volatile cues and dispersal behaviour on 2-dimensional substrates. Positive directional response to chemical cues and similar distances travelled on smooth (agar) or nictation substrates (agar overlaid with sand grains) by Heterorhabditis bacterio-phora, Heterorhabditis megidis, Steinernema anomali, and Steinernema glaseri suggest their cruising approach to finding hosts. The absence of directional response and less distance travelled on nictation substrate, than on smooth agar by Steinernema carpocapsae and Steinernema scapterisci suggest their ambushing mode of foraging. Steinernema feltiae and Steinernema sp. responded directionally to host volatiles, but travelled less distance on the nictation substrate than on smooth agar; the two species also did not nictate. The cruiser species located hosts more effectively in the sand columns, whereas the ambushers were more effective at finding hosts on filter paper. Steinernema feltiae and Steinernema sp. performed equally on filter paper and in the sand column. We conclude that H. bacteriophora, H. megidis, S. anomali and S. glaseri cruise to find hosts, whereas S. carpocapsae and S. scapterisci ambush hosts. Steinernema feltiae and Steinernema sp. are intermediary in the search continuum sharing some characteristics of both ambush and cruise foragers.
The effects of parasitism by larval Digenea on the digestive gland of the intertidal prosobranch,Littorina saxatilis(Olivi) subsp.tenebrosa(Montagu)
Authors: James B. L. 
Published: June 2009

The effects of parasitism by five species of larval Digenea on the digestive gland cells ofLittorina saxatilis(Olivi) subsp.tenebrosa(Montagu) were investigated by comparing histochemically stained cells in healthy, starved and parasitized animals.Two distinct effects were apparent: (a) The germinal sacs compress the walls of the digestive gland tubules and block the lumen. Since food cannot pass this block, digestive gland cells behind undergo starvation autolysis. (b) In digestive gland tubules not cut off from their food supply, glucose, glycogen, glycoproteins and lipid food storage globules are reduced and there is a compensatory increase in the number of food vacuoles in the digestive cells; an increase in glucose but a decrease in glycogen in the visceral haemocoel; and an increase in the number of secretory cells, perhaps in order to eliminate the parasite's excretory products from the visceral haemocoel.
Observations on the Morphology and Life Cycle ofNeodiplostomum intermedium(Trematoda: Diplostomatidae)
Authors: Pearson J. C. 
Published: June 2009

1.Neodiplostomum intermediumPearson is recorded from four new hosts; as an adult from the water rat,Hydromys chrysogasterGeoffroy, and as a metacercaria (diplostomulum), from tadpole and adult of an undescribed tree frog,Hylasp., tadpole of (Hyla latopalmata(Günther)Mixophyes fasciolatusGünther and frog of an unidentified leptodactylid.2. The life cycle ofNeodiplostomum intermediumwas followed experimentally; the hosts were:Pettancylus assimilis(Petterd), a fresh-water limpet, as first intermediate host; tadpole ofHyla pearsoniCopland as second intermediate host;Hyla caerulea(Shaw) a tree frog, andHemisphaerodon gerrardiPeters, the pinktongued skink, as paratenic hosts; andRattus assimilis(Gould) and laboratory rats as definitive hosts.3. Descriptions are given of the morphology of the miracidium, mother sporocyst, daughter sporocyst, cercaria, and diplostomulum, with special reference to the structure of the miracidium and of the cercarial tail.4. Observations are given on the embryology of the miracidium, hatching of the egg, transformation of the miracidium into the mother sporocyst with special reference to the germinal cells, the route and manner of escape of cercariae from the snail host, the development of the diplostomulum with special reference to the reserve excretory system, and the movements of diplostomula during metamorphosis of the tadpole host.5. The haploid chromosome number is ten, as determined from squashes of testes. One paratype and a series of experimental adults have been compared with and found different fromNeodiplostomum(Fibricola)sarcophilusn.comb. The orthography and formal proposing of the names of the species ofFibricolatransferred toNeodiplostomumby Pearson (1959b) are corrected.The writer wishes to thank Dr M. J. Mackerras, Queensland Institute for Medical Research, for generously supplying water rats; Professor J. F. A. Sprent, University of Queensland Veterinary School, for his criticism of the manuscript; Mr K. Webber and his sons for their assistance in catching rats and for permission to collect snails, frogs and tadpoles from their streams; and Mr R. J. Ballantyne for technical assistance. This study was supported by a grant from the Rural Credits Fund of the Commonwealth Bank of Australia.
New species of Near Eastern agamid scale-mites (Acarina, Pterygosomidae) with notes on the developmental stages of Geckobia hemidactyli Law., 1936
Authors: Jack K. M. 
Published: June 2009

The following new species are described:Pterygosoma sinaita sp.nov. (♀, ♂ nymph) off Agama sinaita, A. mutabilis and A. inermis.P. adramitana sp.nov. (♀, ♂) off A. adramitana.P. mutabilis sp.nov. (♀, ♂ nymph) off A. mutabilis, A. pallida, A. jayakari and A. inermis.P. singularis sp.nov. (♀) off A. colonorum.P. caucasica sp.nov. (♀, ♂ deutonymph, protonymph and larva) off A. caucasica.P. foliosetis sp.nov. (♀, nymph) off Charasia dorsalis.Descriptions are also included of the hitherto unrecorded male, nymph and larva of Geckobia hemidactylus Lawrence, 1936, from Hemidactylus mercatorius Gray from Ascension Island.
Pathology in Antechinus stuartii (Marsupialia) due to Demodex sp.
Authors: Nutting William , Woolley Patricia 
Published: June 2009

Pathological manifestations occasioned by mites of the genus Demodex are reported from Antechinus stuartii, a marsupial mouse. Derangements from single mite invasion of a hair follicle to massive nodule formation are detailed. In heavy infestations mites are found well distributed in the skin of the body with nodules limited, however, to the head, hind legs, around the base of the tail, the cloacal regions and, in females, just anterior to the pouch area.Mites invade the hair follicle, where increase in their numbers leads to hypertrophy of the follicular epithelium which forms marked lobules surrounded by heavily vascularized connective tissue. It is thought that destruction of the lobule cells and penetration of the blood vessels due to increased mite numbers and activity leads to leucocytic infiltration with destruction of the mites and nodule deflation. In two instances of nodule deterioration a thickened skin plaque with markedly reduced mite populations remained in place of the nodule.Gross symptoms of demodicidosis are occasionally marked in animals maintained in the laboratory but have not been found in specimens from the field. This suggests that environmental or dietary factors may be important in the onset of gross symptoms of demodicidosis.This investigation was supported in part by a National Science Foundation (U.S.A.) grant (G-23321) and by a Commonwealth Scientific and an Industrial Research Organization (Australia) grant for marsupial research to the Zoology Department, A.N.U.Dr Herman Beerman, Professor and Chairman, Department of Dermatology, Graduate School of Medicine, University of Pennsylvania, very kindly read and criticized our interpretation of the pathology. We are grateful for his help.We would like to thank Margaret Dahlquist, Research Assistant, for her excellent technical assistance in the preparation of material for this report.
The age and sex of the host as factors affecting the host–parasite relationship of the third-stage larva of Amplicaecum robertsi Sprent & Mines, 1960, in the laboratory mouse
Authors: Dobson Colin 
Published: June 2009

There was no difference between the worm burdens or the lengths of the worms recovered from sexually immature male and female mice infected with Amplicaecum robertsi.In mice older than 70 days there were fewer larvae recovered from the female than the male host. The larvae were also longer in the male than in the female mouse.The suckling mouse harboured fewer larvae than the weanling; the susceptibility of the mouse continued to increase with increasing age until the one-hundredth day in the males and the seventy-fifth day in the females. In animals older than this an age resistance was apparent. It is suggested that the much lower susceptibility of the suckling mouse is due to the small gut and villi size reducing the establishment of the larvae.Worm growth also varied with host age, the longest larvae being recovered from the suckling mice and successively smaller worms from each older age group up to the seventy-fifth day, beyond which there was no significant change in worm growth with age of the host. There was no difference between the worm burdens and the lengths of the worms recovered from 90-day-old mice. The injection of testosterone had little or no effect on the host–parasite relationship of gonad-ectomized animals. Larvae from gonadectomized mice were significantly shorter than those from the intact hosts.
An electron microscope study of the tegument and associated structures of Proteocephalus pollanicoli
Authors: Threadgold L. T. 
Published: June 2009

The tegument of Proteocephalus pollanicoli is organized at two levels. The external level is a syncytial layer of protoplasm composed of vesicles in a granular matrix. The surface of this level has microvillus-like structure, microtriches, with sharp electron dense tips and less dense bases. Pinocytotic vesicles, large vacuoles, and evaginations occur at the surface of the external level, whereas mitochondria and lipid droplets tend to be concentrated basally. The basal plasma membrane has in some places small invaginations and at others large evaginations forming protoplasmic tubes which connect the external and internal levels.The internal level is composed of individual areas of dense, granular protoplasm, each of which has a nucleus. These areas, or cuticular cells, contain lipid droplets, mitochondria, short lengths of agranular endoplasmic reticulum and phospholipid bodies. Two cuticular cells lying close together may be joined by a protoplasmic bridge and thereby form a limited syncytium.The morphology of the tegument of this proteocephalid is compared with that of the cyclophyllidean species and the function of the tegument in parasitic helminths is discussed.I should like to acknowledge the technical assistance of Mr W. Ferguson and Mr A. Lyness. My thanks are also due to the Wellcome Trust for a grant to purchase the Akashi Transcope and ancillary equipment.
Differentiation of three species ofNeoaplectan(Nematoda: Rhabditida), grown axenically
Authors: Jackson George J. 
Published: June 2009

Three species of the genusNeoaplectana, nematodes from insects, when grown axenically, could be differentiated consistently by morphological, cultivational and serological criteria.All three species were cultivated for consecutive generations on solid media such as a rabbit kidney slice at the bottom of an enriched agar slant. In axenic cultures with various liquid media, including some which were chemically defined, the ensheathed larvae ofN. glaserimatured and produced offspring which in turn developed and reproduced;N. dutkii(‘DD-136’) larvae matured, but a new generation did not develop; the majority ofN. carpocapsaelarvae survived but did not mature. LivingN. glaseri, used as a source of antigens to detect homologous antibodies, gave fewer cross-reactions than preparations of sonicated and frozen worms, and fewer false negative reactions than used cultivation media.Morphological differences between the three species in cultures are described.This work was done at The Rockefeller Institute in the department of Dr William Trager, with the technical assistance of June I. Schloemer and, subsequently, Kristin L. Schmidtchen. Preliminary morphological descriptions were made in association with M. B. H. Chitwood of the U.S. Department of Agriculture's Beltsville Parasitological Laboratory in Maryland. The author and work were supported by grants from the U.S. National Institutes of Health, 5-K3-AI-9522 and AI-04842.
The effect of a low protein diet and a glucose and filter paper diet on the course of infection ofNippostrongylus brasiliensis
Authors: Clarke Karen R. 
Published: June 2009

Rats were fed on two deficient diets and were infected withN. brasiliensislarvae. They were autopsied at times ranging from 18 hours to 17 days after infection. The effect of the diets on worm burden, sex ratio of the worms and size of larvae and of worms were noted. Significantly more larvae reached the lungs and intestine in rats fed on glucose and filter paper (G.F.P.) and low protein (L.P.) diets than in controls, the highest numbers coming from G.F.P. rats. Neither the migration rate nor the development of the worms was accelerated by the deficient diets. G.F.P. and control rats lost larvae soon after their arrival in the intestine. Adult worms were lost from rats on the deficient diets before they were lost in significant numbers by controls; this was not due to the initially larger worm burdens in the former rats. G.F.P. and control rats lost the bulk of their infections by 17 days; L.P. rats retained about 50% of the worm burden they had on the fourth day. The effect of the deficient diets on the migratory and adult phase ofN. brasiliensis, and on susceptibility and resistance is discussed.This work was done during the tenure of a Science Research Council Studentship. My thanks are due to Dr E. T. B. Francis for his helpful and critical supervision, and to Professor I. Chester Jones, in whose Department the work was carried out, for the facilities he provided.