bluuebunny/crossref_metadata_2025 huggingface dataset:
Eperythrozoon teganodes sp.nov. (Rickettsiales), parasitic in cattle
Authors: Hoyte H. M. D.
Published: June 2009

Eperythrozoon teganodes is described from the blood of cattle. It is compared with, and is shown to be distinct from, E. wenyoni Adler & Ellenbogen, 1934. E. teganodes is a parasite of the plasma rather than of the erythrocyte. It occurs as fine rods and threads, rings, and rings with a rod or thread attached. (E. wenyoni adheres to the edge and the face of the erythrocyte, appearing as densely staining coccoids and faintly staining disks.) It is suggested that some highly polymorphic species of Eperythrozoon may prove to be a mixture of two or more species.

I wish to thank Professor J. F. A. Sprent for his advice and for criticizing the manuscript, and Messrs J. Ballantyne, C. Boel and F. Mellis for technical assistance. The photographs were taken by Mr E. Hollywood of the Photographic Department of the University of Queensland. I am grateful to Dr D. W. Brocklesby for allowing me to examine his material. This work was aided by facilities and funds provided by the Rural Credits Fund of the Reserve Bank of Australia, and by the Queensland Dairymen's Organization.
The histochemical localization of leucine aminopeptidase in Ascaris lumbricoides
Authors: Lee D. L.
Published: June 2009

1. Leucine aminopeptidase has been detected, histochemically, in the intestine, in the walls of the anterior part of the excretory canals and in the hypodermis of Ascaris lumbricoides.

2. The possible significance of leucine aminopeptidase in the walls of the excretory canal is discussed.

I wish to thank Dr Tate, in whose department this work was carried out, for his advice and encouragement during this investigation and Mr A. Page for technical assistance.
Strain variation in Entamoeba histolytica I. Correlation of invasiveness in rats with the clinical history and treatment of the experimental infections
Authors: Neal R. A. , Vincent Patricia
Published: June 2009

1. Eleven strains of Entamoeba histolytica were isolated from contact carriers and all proved non-invasive to rats.

2. Three strains from cases showing symptoms proved invasive to rats.

3. The treatment of murine infection with non-invasive strains with emetine hydrochloride shows that most of them were successfully cured with six daily oral doses of 2 mg./kg., though one was not susceptible to this dose. Another proved refractory to 4 mg./kg.

4. The results of previous work with kittens are discussed in the light of the present observations.
Anthelmintic studies: IV. The loss of efficiency by division of the dose
Authors: Steward J. S.
Published: June 2009

It has long been customary to use a single large dose in the treatment of worms in animals, but in man there has been a tendency to use a course of doses, especially in the treatment of threadworm. In the case of phenothiazine when used against threadworm the division of the dose has probably been undertaken in order to avoid toxicity. There is, however, no definite evidence that the toxic hazard is reduced in this manner, in fact, it may well be increased as with poorly absorbed substances greater absorption is obtained with the presentation of the treatment over a longer period. This can be clearly demonstrated in laboratory tests.
The filarial worms Dipetalonema digitatum and D. gracile in monkeys
Authors: Webber Winfrith A. F. , Hawking Frank
Published: June 2009

1. Filarial worms were found in the peritoneal cavity of a monkey (Macaca speciosa) from Bengal. They were identified as Dipetalonema digitatum (Chandler, 1929).

2. The microfilariae were unsheathed and showed a well-marked nocturnal periodicity in the blood.

3. No development of the microfilariae was detected in Aëdes aegypti, A. albopictus, Anopheles quadrimaculatus or An. stephensi, but only a few mosquitoes were observed.

4. Six female worms and one male were transplanted into the peritoneal cavity of a rhesus monkey (Macaca mulatta). Ten weeks later microfilariae were found in the blood of the monkey and they persisted for at least 16 weeks.

5. Filarial worms (Dipetalonema gracile) were discovered in the peritoneal cavity of a monkey (Cebus apella) from Brazil.

6. The microfilariae were unsheathed and were found in the blood. They showed no periodicity.

7. No development of the microfilariae was detected in Aëdes aegypti, A. albopictus, Anopheles maculipennis atroparvus or An. stephensi.

8. No pathological lesions due to either of these worms were detected in the monkeys.
Membrane (contact) digestion in the three species of tapeworm Hymenolepis diminuta, Hymenolepis microstoma and Moniezia expansa
Authors: Taylor E. W. , Thomas J. N.
Published: June 2009

The presence of living tapeworm increases the rate of hydrolysis of starch by α-amylase in vitro. This effect indicates that ‘membrane digestion’ may be one function of the tegument of tapeworms. The effect varies with the surface area and region of the tapeworm. Fixed tapeworm pieces do not enhance starch hydrolysis. The results may provide evidence both for and against the current explanations of membrane digestion. Some possible mechanisms involved in membrane digestion in tapeworms are considered. The importance of membrane digestion in the physiology of gut parasites and the possibility of its wide occurrence are discussed.

We wish to thank Dr J. Llewellyn for his criticism and advice during the preparation of this manuscript and for providing rats and mice infected with Hymenolepis. We also thank Dr R. A. Thornhill for examining some tapeworm tissue under the electron microscope; also Mr A. Wilson of the Meat Inspection Department of the Birmingham Meat Market for his unfailing co-operation.
Quantitative studies on the kinetics of establishment and expulsion of intestinal nematode populations in susceptible and immune hosts. Nippostrongylus brasiliensis in the rat
Authors: Jarrett Ellen E. E. , Jarrett W. F. H. , Urquhart G. M.
Published: June 2009

This paper describes the quantitative aspects of establishment and expulsion of Nippostrongylus brasiliensis in the normal and immune rat. It is proposed that this helminth infection may be described in terms of four phases. These are: (1) loss phase 1 (LP1). A proportion of the infecting dose of larvae is immobilized or destroyed before or during the course of migration via the lungs to the intestine. (2) The plateau phase. The worm number remains static in the predilection site. (3) Loss phase 2 (LP2). This is analogous to the self-cure reaction and during this worms are expelled from the host by an immunological mechanism. The onset of the expulsion is sudden and the process is exponential. It continues at a steady rate until a threshold is reached. (4) Threshold phase. A small residual population of worms is not expelled and survives for a fairly prolonged period.

The pattern is maintained in immune animals undergoing second or third infections but there are quantitative differences. With increasing number of infections LP1 becomes greater, the plateau phase is shortened and the expulsion rate of LP 2 increases. It is suggested that the rate coefficient of this phase is an accurate measure of the immune status of the animal. The threshold phase is of a similar order in first, second and third infections. These results are discussed with regard to their significance as a measure of the immune status of the host, their implication regarding the mechanism of helminth expulsion and their relevance to other helminth infections.

The authors wish to thank the Agricultural Research Council and Allen and Hanburys Ltd. for the financial support which made this work possible. During this period Ellen E. Jarrett held a Horserace Betting Levy Board Scholarship.
The formation of the cuticular ridges in the larval pharynx of the blowfly (Calliphora vicina R.-D.)
Authors: Dowding Valerie M.
Published: June 2009

A method for rearing blowfly larvae giving good synchronization of growth is described. Electron microscope studies showed that the lateral lamellae of the pharyngeal ridges each have a swelling at the tip, and that the lamellae from adjacent ridges are interdigitated in a regularly alternate pattern. Formation of the ridges in the second-instar larva begins 8 h before the moult when the four rows of partially syncytial epidermal cells lying beneath the floor of the pharynx begin to form nine dorsal projections. These lengthen and gradually take up the form of the ridges, the fine divisions which are the lateral lamellae being the last feature to develop. After a two-layered epicuticle has been formed the cytoplasm rapidly withdraws from the ridges leaving them, and the new floor of the pharynx, strengthened by a network of fibres. At the moult a further zonse of cuticle, showing parallel striations, is added to the base of the ridges. The lateral lamellae are epicuticular structures. The importance of the intracellular formation of cuticle is discussed.

I should like to thank Dr P. Tate under whose supervision this work was carried out for helpful advice, and wish to acknowledge financial support from the Agricultural Research Council in the form of a Postgraduate Studentship.
The pathogenic effects of Eimeria praecox and E. acervulina in the chicken
Authors: Long P. L.
Published: June 2009

Eimeria praecox produced less effect on body-weight gain and food consumption than E. acervulina. No deaths occurred and no weight loss followed infection with doses of oocysts up to 10. However, there was a depression of body-weight gain in birds infected with both species and changes in the permeability of the intestine were noted from as early as 3½ h after infection. This suggests that increased intestinal permeability is not the major factor in the greater pathogenicity of E. acervulina compared with E. praecox. Eimeria acervulina produced considerably greater effects on the host as evidenced by mortality, body weight gain and food consumption.

I wish to thank Mr B. J. Millard and Mr M. Shirley for technical assistance and Dr B. M. Freeman for help with the statistics in Table 2.
The growth of an axenic strain ofEntamoeba invadensin different media
Authors: McConnachie Elspeth W.
Published: June 2009

The growth of an axenic strain ofEntamoeba invadensin two media (Trypticase–liver broth and Trypticase–Panmede) is compared with that of a monobacterial strain in diphasic medium supplemented with starch. The axenic strain multiplied more slowly, and produced lower yields of amoebae than the monobacterial strain.

Amoebae multiplied more rapidly and produced higher yields in Trypticase–liver broth than in Trypticase–Panmede.

The effect of certain variations in the basic Trypticase–Panmede medium was investigated. Serum stimulated the growth of the axenic strain in Trypticase–Panmede, so that although the initial multiplication rate was not increased, the maximum yields of amoebae were increased to levels that varied according to the concentration of the serum.

The multiplication of the axenic amoebae was depressed by procedures which probably aerated the medium.

I thank Dr L. S. Diamond for axenic strain NIH:200 ofE. histolytica, and Professor E. Meerovitch for axenic strain PZ ofE. invadens. I am much indebted to Dr P. Whittlestone, of the Department of Animal Pathology, Cambridge, who examined cultures of strain N for the presence of mycoplasmata. The work was carried out while the author was a member of the scientific staff, Medical Research Council.
The ultrastructure of the adult stage ofTrichostrongylus colubriformisandHaemonchus placei
Authors: Smith Kenneth , Harness Eric
Published: June 2009

The ultrastructure of the adult stage ofT. colubriformisandH. placeiwas studied. The cuticle of both nematodes was composed of (1) a membrane-bound layer, (2) external cortex, (3) inner cortex, (4) matrix, (5)–(7) three fibre layers, and (8) a basal lamella. Pear-shaped bodies embedded in the matrix layer inH. placeioccur, along the length of the animal, once per annulus. A thin hypodermis enlarged to form lateral, dorsal and ventral cords which contained hypodermal cells, nerves and excretory canals. The muscle cells were large and multilobular. Two sizes of myofilaments, present in the contractile part of the cell, conformed to the filament arrangement of obliquely striated muscle. The mouth, buccal cavity and oesophagus of the alimentary tract were lined with cuticle. The oesophagus contained gland cells, muscle cells and apical cells. The lumen of the intestinal cells of both species had a well-developed microvillar border. InH. placeieach microvillus was encircled by a ring of apparently spirally orientated vesicles or tubules.

The authors are grateful to Dr D. W. Brocklesby for his help and advice. They would also like to thank Dr D. L. Lee and Dr W. G. MacMillan for helpful discussions.
The effects of drugs on worm expulsion in theNippostrongylus brasiliensisinfected rat: a discussion of the interpretation of drug action
Authors: Keller R. , Ogilvie Bridget M.
Published: June 2009

In rats treated with compound 48/80 or histamine, worm expulsion was inhibited. Treatment with a histidine decarboxylase inhibitor accelerated worm expulsion. Treatment with compound 48/80 elevates histamine and histidine decarboxylase levels and reduces circulating reagin titres. These results show that histamine is not responsible for worm expulsion.

Compounds such as isoprenaline and theophylline which increase cellular levels of cyclic 3′,5-AMP, prevented worm expulsion.

It is concluded that the evidence that amines are involved in worm expulsion needs reassessing and that cellular release mechanisms in general may be affected by drugs thought to act solely on amine release. In particular, the release of effector substances from sensitized lymphocytes on contact with antigen may be affected by these treatments.

The skilful technical assistance of Miss R. Keist and Miss I. Beeger is gratefully acknowledged. We thank Mr H. Berchtold, Biostatistisches Zentrum der Universität Zürich, for the statistical evaluation of the data.
Baylisascaris tasmaniensis sp.nov. in marsupial carnivores: heirloom or souvenir?
Authors: Sprent J. F. A.
Published: June 2009

A new species of ascaridoid nematode, Baylisascaris tasmaniensis, is described from three marsupial carnivores of Tasmania, namely Sarcophilus harrisi, Dasyurus viverrinus, and Dasyurops maculatus. The new species is differentiated from other species in the genus Baylisascaris and the phylogenetic affinities within the genus are discussed in relation to the origin of the placental and marsupial carnivores.
The oncomiracidium of the monogenean Discocotyle sagittata
Authors: Owen I. L.
Published: June 2009

A description is given of the morphology and behaviour of the oncomiracidium of the monogenean D. sagittata. The larva has many features in common with the oncomiracidium of Diplozoon paradoxum but its development is less precocious than the latter. Suggestions are made as to the possible relationships of a pair of degenerate hooks on the haptor.
Observations on the effect of the rediae of Fasciola hepatica on the lipid composition of the hepatopancreas of Lymnaea truncatula
Authors: Southgate V. R.
Published: June 2009

In the uninfected hepatopancreas of L. truncatula 7·0–11·0% of the dry weight is lipid. Of the total lipid 60% is neutral lipid and 40% is phospholipid. Free fatty acid is the major neutral lipid component; triglycerides, diglycerides, monoglycerides, sterols and esterified sterols are also present. The phospholipids identified were phosphatidyl choline, phosphatidyl ethanolamine, lyso-phosphatidyl choline and sphingomyelin. The fatty acids were analysed by gas chromatography. The major fatty acid is C16 (palmitic) and 60% of the total fatty acids are saturated.

In the hepatopancreas of L. truncatula infected with the rediae of F. hepatica, but with the rediae removed, 5·4–9·4% of the dry weight is lipid. Of this total lipid 73% is neutral lipid and 27% is phospholipid. All the fractions of neutral lipid, except the fatty acids are smaller than in the uninfected hepatopancreas. The fatty acids show an increase of 38%. The same phospholipids identified in the uninfected hepatopancreas are present, but all the fractions show a decrease in amount with the exception of the phosphatidyl choline fraction, which is present in approximately equal amounts in both the uninfected and the infected hepatopancreas. The major fatty acid is palmitic acid.
Neoglyphe soricis (=Opisthioglyphe soricis Pojmańska, 1956), (Trematoda: Plagiorchiidae) from shrews in Alaska
Authors: Seesee Floyd M.
Published: June 2009

An intestinal trematode of shrews previously identified as Opisthioglyphe locellus Kossack, 1910, by Macy & Moore (1958) in Oregon is identified as Neoglyphe soricis (= Opisthioglyphe soricis) originally described from Sorex araneus L., in Poland by Pojmańska (1956). N. soricis found in Sorex cinereus, near Anchorage, Alaska, is a new host and new locality record. N. soricis, the only species of Neoglyphe known from North America, is compared with its Eurasian counterpart and closely related species. Evidence supporting the retention of the genus Neoglyphe originally proposed as a subgenus by Shaldybin (1953), and raised to generic rank by Yamaguti (1958), and invalidated by Zarnowski (1960), is presented.
Lepocreadid trematodes of marine fishes of India
Authors: Hafeezullah M.
Published: June 2009

Eleven lepocreadiid trematodes from marine fishes of India are reported. Known species are: Aephnidiogenes senegalensis Dollfus & Capron, 1958, Lepocreadioides indicum Srivastava, 1941, Bianium plicitum (Linton, 1928) Stunkard, 1931, B. bombayensis Gupta, 1968, and Pseudocreadium patellare (Yamaguti, 1938) Manter, 1940. New genera are: Pseudolepocreadioides and Transversocreadium. New species are: Pseudolepocreadioides symmetrorchis, Transversocreadium cablei, Crassicutis karwarensis, Diplocreadium triacanthi, Lepidapedon longivesiculum and L. manteri. Bianium madrasi Gupta, 1968, is considered a synonym of B. plicitum and the genus Diplocreadium Park, 1939, is considered valid.
The effect of a milk diet uponPlasmodium berghei, Nuttallia (=Babesia) rodhainiandTrypanosoma bruceiinfections in mice
Authors: Nowell Frank
Published: June 2009

Suppression ofP. bergheiinfections but not those ofN. rodhainiorT. bruceiin mice on milk diet were noted. The suppression ofP. bergheiwas variable. This was not due to differences of the quality of the milk or to the mice eating faeces, sawdust, etc. which may be rich in PABA. The variability was at least partially due to selection of a strain of parasite probably requiring a lower level of PABA than normal. One such strain was isolated and its pattern of infection compared with the normal strain. The ‘milk diet’ strain caused a higher fatality rate in mice on milk diet but always showed a lower parasitaemia growth rate in mice on normal diet. When repassaged through mice on normal diet, the ‘milk diet’ strain did not revert immediately to the infection pattern of the normal strain.
The glucose metabolism of adult Ostertagia circumcincta, in vitro
Authors: Ward P. F. V. , Coadwell W. J. , Huskisson N. S.
Published: June 2009

Adult Ostertagia circumcincta from freshly killed sheep were incubated at 39 °C in a medium containing inorganic salts, antibiotics and D-[U-14C] glucose. The worms appeared healthy even after incubation for as long as 72 h. All the radioactivity was recovered either within the worms or in the incubation vessel in the form of metabolic products or unmetabolized glucose. Incubations were carried out at low oxygen tension except for those in which CO2 was measured. These were either aerobic or anaerobic. In terms of both quantity and radioactivity the main metabolic products of glucose were CO2, propan-1-ol, acetate and propionate. Smaller amounts of ethanol, lactate and succinate were formed. The results are compared with those found for the similar nematode Haemonchus contortus.
Taxonomy of trypanosomes (Protozoa: Trypanosomatidae) ofSpermophilusspp. (Rodentia: Sciuridae)
Authors: Hilton Donald F. J. , Mahrt Jerome L.
Published: June 2009

(1)Spermophilus columbianus, S. franklinii, S. lateralis tescorum, S. richardsonii, S. tridecemlineatusands. undulatus plesius(ground squirrels) were collected from Alberta and Yukon Territory (S. u. plesiusonly), Canada. Trypanosome infections were detected in all butS. l. tescorum. (2) All six species of squirrels were experimentally inoculated with trypanosomes from naturally infectedS. columbianus, S. franklinii, S. richardsoniiandS. tridecemlineatus. The strains fromS. columbianus, S. richardsoniiandS. tridecemlineatusproduced infections in some or all of the other host species, whereas the strain fromS. frankliniidid not. (3) Natural transmission of trypanosomes has not been demonstrated, but it seems likely that fleas act as vectors. (4) Intensities and durations of experimental infections were variable and depended upon the trypanosome strain, host species and individual. Infections were non-pathogenic. (5) Previously infected ground squirrels could not be reinfected with the same or a different trypanosome strain and immunity appeared to be lifelong. (6) Size comparisons among and within trypanosome strains from naturally and experimentally infected ground squirrels revealed that the strains fromS. frankliniiandS. tridecemlineatuswere similar to one another, but different from the other three trypanosome strains (those fromS. columbianus, S. richardsoniiandS. undulatus). (7) It is suggested that there is only one species of trypanosome,Trypanosoma otospermophili, in the genusSpermophilusin North America and that differences in size and types of infection are due to host-induced variations (i.e. they are plastoxenodemes).T. spermophili(present in EurasianSpermophilusspp.) might be synonymous withT. otospermophili.
Gland cells in the redia of Fasciola hepatica
Authors: Wilson R. A.
Published: June 2009

Gland cells surrounding the oesophagus in the redia of Fasciola hepatica are described. These cells produce electron-dense, membrane-bound vesicles which have an unusual mechanism for secretion of their contents.
Ultrastructural and cytochemical studies on the sensory organelles and nervous system ofDipetalonema viteae(Nematoda: Filarioidea)
Authors: McLaren Diane J.
Published: June 2009

The sensory organelles and some components of the nervous system of the adult filarial wormDipetalonema viteaehave been studied by means of electron microscopy. The sensory organelles contain modified cilia innervated by nerve axons. The cilia lie within cuticle-lined channels. The amphids each contain nine such cilia, but the phasmids and the papillae contain only one cilium. The amphidial and phasmidial cilia are exposed to the external environment and it is suggested that I they function as chemoreceptors. The cilia within the cephalic and caudal papillae are modified so as to produce a greater area of sensitivity. The ciliary channels in the cephalic papillae do not open to the exterior and these papillae therefore probably function as mechanoreceptors. The caudal papillae of the male worm are structurally similar to the cephalic papillae, except that the ciliary channels are open to the external environment. It is suggested that these papillae function both as mechanoreceptors and chemoreceptors. The terminal pair of caudal papillae differ from all the other papillae. The ciliary channels of all the sensory organelles are surrounded by supporting cells, but multivesicular cells are only associated K with the amphids, phasmids and cephalic papillae. The nerve-ring encircles the muscular region of the oesophagus; it is composed entirely of nerve axons. The nerve axons contain two kinds of vesicle. The nervering is surrounded by an ensheathing cell. The major nerve bundles are carried by the hypodermal cords, but they are not embedded in the hypodermal cytoplasm. The nerve axons at the surface of the cord form synapses with the innervation processes of the somatic muscle cells. Electron cytochemical techniques have been used to investigate the distribution of cholinesterases in the structures described. Acetylcholinesterase has been identified in the amphids, phasmids, cephalic papillae and nerve-ring; it is suggested that acetylcholine functions as a chemical transmitter at these sites. Pseudocholinesterase has been identified in the amphids, phasmids and cephalic papillae, but not the nerve-ring; it is present in considerably smaller quantities than acetylcholinesterase.
Entopolypoides macaci, a Babesia-like parasite in Cercopithecus monkeys
Authors: Hawking Frank
Published: June 2009

A description is given of a Babesia-like parasite found in the erythrocytes of two Cercopithecus pygerythrus monkeys probably from East Africa. Morphologically it seems identical with a parasite found by Mayer (1934) in Macaca irus monkeys from Java and named by him Entopolypoides macaci. On the other hand, the present African type differs from the Javan one in that it does not readily infect M. irus or M. mulatta monkeys; and it might well be named provisionally E. macaci (cercopitheci).
Morphologically, the early forms are fine rings with a large vacuole but the more mature parasites form several fine long processes which are best seen under phase-contrast illumination. The cycle in the erythrocytes probably ends by division into four new parasites and it takes 3 days to quadruple the number. There is no synchronicity, such as occurs with malaria.
The parasite was passed by syringe into Erythrocebus patas, Papio papio and Cercocebus galeritus monkeys in which it produced a light parasitaemia if they were intact, or an intense one (up to 70% erythrocytes parasited) if they were splenectomized. In both cases the bouts of parasitaemia are prolonged for weeks, and they may continue with relapses apparently for years. A light transient infection was produced in one splenectomized Macaca mulatta and in one out of two intact M. irus monkeys, but not in one M. arctoides (splenectomized), one Cebus albifrons, one C. apella, two Aotus trivirgatus and two Pan troglodytes (one splenectomized). Apparently the parasite readily infected African lower primates, hardly infected Asiatic ones, and did not infect American ones.
Even in susceptible splenectomized monkeys, in which it produced prolonged intense parasitaemia, the parasite causes little pathogenic effect beyond a moderate anaemia.
Attempts were made to transmit it through Rhipicephalus sanguineus, Dermacentor andersoni, Ornithodoros (sp.), Ornithonyssus bacoti and Aedes aegypti but they were unsuccessful. Probably the vector is an Ixodid tick.
Chemotherapeutically the parasite was sensitive to a babesicidal compound, Imidocarb (3,3′-bis-(2 imidazolin-2yl) carbanilide) and to primaquine but not to chloroquine, pyrimethamine, pentamidine, Berenil or homidium.
A high infection rate of Trypanosoma brucei subgroup in Glossina fuscipes
Authors: Rogers A. , Kenyanjui E. N. , Wiggwah A. K.
Published: June 2009

A survey in Busoga District, Uganda, where an outbreak of sleeping sickness was detected, has yielded an infection rate with T. brucei subgroup in G. fuscipes of 4.8%. Isolation of the infected flies was by feeding of the flies on mice, followed by trituration and inoculation of a suspension of the triturated flies into mice. The mice were treated with cyclophosphamide to reduce the immune response.
The percentage infection as determined by inoculation of triturate was 4.1%, whilst that by feeding on mice was 1–8%.
Amongst the 19 strains of T. brucei subgroup isolated, four were identified as T. rhodesiense by the BIIT method.
Observations on the establishment of Polymorphus minutus (Acanthocephala) in the intestines of domestic ducks
Authors: Lingard Ann M. , Crompton D. W. T.
Published: June 2009

No external signs of activation of cystacanths in the alimentary tract were observed until 25 min after oral ingestion. Peak percentage evagination was observed after 60 min.
Activation and establishment of cystacanths were never found in the ventriculus or anterior to it, but several crushed specimens were found in the ventriculus, which is a mechanical hazard to the parasite.
Infections established by cannulation at the yolk-stalk are greater than infections produced by ingested parasites; thus the ventricular environment does not need to be experienced by the freed cystacanth for activation to take place.
The role of melanization in the immune reaction of larvae ofDrosophila algonquinagainstPseudeucoila bochei
Authors: Nappi A. J.
Published: June 2009

The immune reaction of larvae ofD. algonquinagainstP. bocheiwas characterized either by the melanization and encapsulation of the parasites or by the production of melanized particles. In successful host reactions the eggs of the parasite were killed before they were completely melanized and encapsulated by haemocytes. When host larvae were transferred during the early stages of infection to a diet that contained phenylthiourea (PTU), the incidence of melanization and encapsulation of the parasites was significantly reduced. However, if the hosts were transferred to the diet just before the eggs of the parasite were normally melanized, PTU had virtually no inhibitory effect, and the immune reaction rate remained very high. These results suggest that the biochemical reactions associated with melanization constitute an important part of the immune reaction ofD. algonquin. The data provide additional evidence to support the idea advanced by other workers that the phenoloxidase system plays an important role in insect immunity against some internal metazoan parasites. It is suggested that, during infection, the phenoloxidase system of the haemocytes is activated by hormonal imbalance.
Structure and development of Lobatostoma manteri sp.nov. (Trematoda: Aspidogastrea) from the Great Barrier Reef, Australia
Authors: Rohde Klaus
Published: June 2009

Lobatostoma manteri sp.nov. is described. It differs from other species of this genus in the number of marginal alveoli (usually 56–62), the location of the testis near the posterior end and the large size of the cirrus pouch. Mature worms occur in the intestine of the fish Trachinotus blochi. Eggs containing fully developed larvae are laid. The eggs are eaten by snails and hatch in the stomach. Larvae have an oral sucker, pharynx, simple caecum, ventro-terminal acetabulum, two dorsal excretory bladder cells in front of the acetabulum, and a caudal appendage. They migrate into the digestive gland and differentiate to pre-adults with fully developed genital organs and the full number of alveoli on the adhesive disk; young spermatozoa and egg cells develop but do not mature. Pre-adults have a minimum number of 8500 sensory papillae on the surface. The worms are usually found in a cavity formed by enlargement of the main duct and one or more (?) side ducts of the digestive gland near the stomach in Cerithium moniliferum, or in the stomach and main ducts of the digestive gland of Peristernia australiensis. They may creep from the ducts into the stomach and back into the ducts. Fish become infected by eating snails. Worms from fish die soon after transfer into sea water but can be kept alive for up to 13 days in frog's Ringer solution or dilute sea water (1:5), in which they lay eggs containing larvae infective to snails. Worms from snails remain alive in sea water, dilute sea water, frog's Ringer or Tyrode solution. Eggs of worms from single infections have the haploid chromosome number of 7; there is normally no self-fertilization and development does not reach the blastula stage. The life-cycle of Lobatostoma manteri is the simplest two-host cycle of trematodes known. Reasons are given why it must be considered the most primitive one, of a type from which digenean life-cycles have evolved.
Observations on arcade cells and pseudocoelomocytes in some oxyuroid nematodes parasitic in cockroaches
Authors: Peregrine Pauline C.
Published: June 2009

Regions have been identified in certain oxyuroid nematodes which stain vitally with quinone-imine dyes. Thelastoma attenuatum shows colour in the arcade cells, the small pseudocoelomocytes and the giant pseudocoelomocytes; while Leidynema appendiculata and Hammerschmidtiella diesingi possess only giant pseudocoelomocytes. All these regions have been studied.

The giant pseudocoelomocytes in all three species are apparently very active, but their precise function had not yet been assessed.

The structure of the arcade cells and small pseudocoelomocytes of Thelastoma have been described. These regions may also be active but their function is again not understood.

Further work to elucidate these problems is suggested.
The output of cercariae of Fasciola hepatica by Lymnaea truncatula and the distribution of metacercariae on grass
Authors: Hodasi J. K. M.
Published: June 2009

It has been demonstrated that under normal laboratory conditions Lymnaea truncatula infected with Fasciola hepatica are not able to shed all their cercarial loads before their death. Cercariae are irregularly released over an extended period and considerable variations (4–1789) occur in their output.

Laboratory studies have revealed that the green parts of grass (Dactylis glomerata) are preferred to the brown, dead parts by the cercariae of Fasciola hepatica for metacercariae formation. More cysts are formed on the lower surface of submerged leaves than on the upper surface.

There is vertical zonation of metacercariae on grass in water. More cysts occur on the upper parts of submerged grass than on the lower parts.

Vertical migration of cercariae after settling does not usually occur before cyst formation.

The results are tabulated and discussed and correlated with conditio s in the field.

This work was undertaken in the Department of Zoology, University of Bristol, Bristol, under the supervision of Dr H. D. Crofton, to whom I wish to express my gratitude.
Minocycline in the chemotherapy of murine toxoplasmosis
Authors: Tabbara K. F. , Sakuragi S. , O'connor G. R.
Published: June 2009

The effects of minocycline alone or in combination with sulphadiazine were evaluated against acute murine toxoplasmosis and compared with the efficacy of pyrimethamine and sulphadiazine. The data presented show that mice could be protected from acute toxoplasmosis by minocycline, in spite of using a virulent strain ofToxoplasma gondii, a large inoculum, and a delay in the administration of the drug. Acute toxoplasmic infection in mice could be eradicated by a minocycline–sulphadiazine combination, which was found to be as effective as pyrimethamine–sulphadiazine combination therapy.
The structure and possible function of the ventral papillae of Notocotylus triserialis Diesing, 1839
Authors: MacKinnon Barbara M.
Published: June 2009

Notocotylus triserialis bears three rows of eversible papillae on its ventral surface. These papillae, which in living worms are firmly applied to the host mucosa, contain numerous pyriform cells. Histochemical tests indicate the presence, within the papillar cells, of protein, lipid, haemoglobin and esterase, and the absence of carbohydrate, acid mucopolysaccharide, RNA, haemosiderin and acid and alkaline phosphatase. Transmission electron microscopy shows the tegument of the papillae to be similar to the non-papillar ventral tegument. The pyriform cells contain many mitochondria with numerous cristae. A mechanism is proposed whereby the musculature of the worm effects the retraction and eversion of the ventral papillae.
The asexual and sexual circadian rhythms of Plasmodium vinckei chabaudi, of P. berghei and of P. gallinaceum
Authors: Hawking Frank , Gammage Kenneth , Worms Michael J.
Published: June 2009

Plasmodium vinckei chabaudi (which has a 24 h cycle with high synchronicity) has a peak of schizogony in the early morning at about 02.00–04.00. This cycle is orientated to the cycle of the host (mouse or thamnomys). The male gametocytes become ripe for exflagellation in a well-marked wave from 22.00 to 08.00 with peak about 00.00–04.00. This timing presumably corresponds to the hours when the vector mosquitoes are most likely to suck blood, and it is adapted to facilitate transmission. The male gametocytes remain ripe for exflagellation for a mean period of about 6 h and then apparently degenerate.
The effects of temperature and other factors upon the establishment and survival ofPomphorhynchus laevis(Acanthocephala) in goldfish,Carassius auratus
Authors: Kennedy C. R.
Published: June 2009

Goldfish were experimentally infected with different population densities of the acanthocephalanPomphorhynchus laevis, and maintained at different temperatures. The density of infection had no effect upon the establishment of the parasite, but a 12°C rise in water temperature reduced the recovery after one week by 30%. Thereafter there was a continuous loss of parasites during the course of infection. The rate of this loss was independent of worm burden and temperature, but increased under conditions of host starvation. Both male and female parasites attached themselves in the same region of the alimentary tract, with a mean position about 19% along its length. They remained in that region throughout the course of infection, and the population did not migrate down the intestine with increasing age. In starved fish, the region of attachment was nearer the oesophagus, at low temperatures nearer the rectum, and when crowded the occupied region extended anteriorly. Male worms were unable to establish as easily as females, but once established survived better, and the sex ratio after two weeks was in favour of males. The results are compared with the results of studies on other acanthocephalans and on fish-cestode systems. It is recognized that although the establishment of fish acanthocephala is affected by temperature to a lesser extent than that of some fish cestodes, temperature in conjunction with changes in fish diet is a major control upon the flow of parasites through acanthocephalan-fish parasite systems. The significance of the results to the interpretation of data based on field observations is discussed.
Observations on the envelope surrounding Moniliformis dubius (Acanthocephala) in the intermediate host, Periplaneta americana
Authors: Lackie J. M. , Rotheram Susan
Published: June 2009

Ultrastructural observations on Moniliformis dubius, combined with measurements of envelope volume and composition at various stages during the parasite's development, suggest that production of envelope material is essentially complete by the stage at which elevation occurs. Elevation is associated with the production of an inner layer. In vitro observations on acanthors show that membranous coat material can be produced in the absence of haemocytes.
The effects of Fasciola hepatica on Lymnaea truncatula
Authors: Hodasi J. K. M.
Published: June 2009

Among the functional changes observed in L. truncatula infected with F. hepatica were those of growth, reproduction and mortality. For the first 3 weeks after infection there was no difference between the growth of infected and uninfected groups of snails. Thereafter there was a temporary accelerated growth which occurred between the fourth and seventh weeks after infection. The onset of this period of rapid growth in the different age groups of infected snails coincided with the time of migration of the rediae into the hepatopancreas.
Of more significance was the influence of infection on the reproduction of the snail. There was a sharp decline in oviposition 2–3 weeks after infection, followed by a complete cessation of egg production at the end of the fifth week. Once oviposition ceased, it was not resumed and there was no self-cure.
Contrary to general belief, infected groups of L. truncatula have been found to live longer than the uninfected controls. With isolated snails, however, there was a tendency for the uninfected snails to live longer than the infected ones. The possible interpretation of the discrepancies between isolated and mass cultured snails are discussed.
The hepatopancreas and the gonad (ovotestis) were the two structures directly affected by the infection. Establishment of the rediae in the hepatopancreas invariably resulted in parasitic castration.
Simultaneous presence of different antigenic populations of Trypanosoma brucei gambiense in Microtus montanus
Authors: Seed John Richard , Effron Harris Gregory
Published: June 2009

Trypanosomes were isolated before and after the formation of infected detectable antibody from various brain sites and the blood of Microtus montanus. All isolates were serotyped by the agglutination reaction, and the isolates obtained prior to antibody formation were serologically identical to the original inoculum. Later isolates obtained from separate sites of an infected animal were serologically different from the original inoculum and also from each other. It was therefore concluded that in a single chronically infected animal there are numerous different antigenic populations of trypanosomes each occupying separate brain sites. A hypothesis to account for this antigenic diversity is given.
Ultrastructural aspects of capsule formation in Trichinella spiralis infection in the rat
Authors: Teppema J. S. , Robinson Joke E. , Ruitenberg E. J.
Published: June 2009

The encapsulation of Trichinella spiralis larvae in host striated muscle was studied.

Capsule formation starts at 13 days post-infection. Between days 20–50 p.i. the largest increase in capsule formation was observed. The capsule is exclusively, or almost exclusively, formed from and by the infected muscle fibre, as might be concluded from the presence of the sarcolemmal basal lamina surrounding the capsule substance during the initial stages of capsule formation. A collagen nature of the capsule cannot be excluded.
The early development of immunity to Eimeria maxima in comparison with that to Eimeria tenella
Authors: Rose M. Elaine
Published: June 2009

Immunity to Eimeria maxima, judged by oocyst production resulting from a low challenge inoculum, was evident when the challenge was given as early as 3 days after the immunizing dose of 250 or 500 oocysts. Immunity was complete, i.e. no oocysts were produced, to challenge at 7 days after an initial inoculum of 500 oocysts, or at 14 days after 250 oocysts. Judged by the above criteria 250 oocysts of E. tenella did not induce immunity to challenge given at 3, 5, 7 or 14 days. The findings are discussed.
An electron microscope study of the tegument of the metacercaria and adult of Leucochloridiomorpha constantiae (Trematoda: Brachylaemidae)
Authors: Harris Kevin R. , Cheng Thomas C. , Cali Ann
Published: June 2009

The tegumentary ultrastructure of Leucochloridiomorpha constantiae metacercariae and adults has been described. A filamentous glycocalyx invests the tegument of metacercariae and large numbers of biconcave, disk-shaped secretion vesicles are found in its outer zone, cytoplasmic bridges and cytons. Mitochondria within the outer tegumentary zone of metacercariae are restricted to its basal half. The transformation of metacercariae to adults involves the loss of the glycocalyx, a decrease in the number of disk-shaped secretion vesicles, a more uniform distribution of mitochondria through the outer tegumentary zone, an apparent degeneration of cytons, a thinning of the fibrous basal lamina and a decrease in the number of visible cytoplasmic bridges traversing it. The significance of these events for a metacercaria which does not encyst within the molluscan host is discussed. In addition, crystalline, spine-like inclusions in the outer tegumentary zone of adult L. constantiae are described and their possible function discussed.
Anticoccidial activity of an azauracil derivative
Authors: Ryley John F. , Wilson Robert G. , Betts Michael J.
Published: June 2009

A substituted azauracil derivative has been shown to have marked anticoccidial activity. Chickens given large challenge doses of Eimeria tenella were protected from mortality by a dietary level of 0·25 ppm drug, while oocyst output was controlled by 10 ppm. Under conditions of continuous medication using 15 ppm of the azauracil derivative the development of E. tenella was arrested at the multinucleate first generation schizont stage; in the majority of parasites merozoite differentiation was inhibited. Experiments using restricted medication indicated that, with E. tenella in the chick, the drug was coccidiocidal rather than coccidiostatic, and that treatment for as little as one day could control the infection. Medication started during the second asexual cycle again resulted in inhibition at the multinucleate schizont stage just before merozoite differentiation. Mortality in birds inoculated with E. brunetti was controlled by 1 ppm azauracil in the diet and oocyst output by 2.5 ppm; unlike the situation with E. tenella, the drug had no influence on the first two asexual cycles of reproduction. There was some inhibition of the third schizogony cycle, but the main effect of the drug in the case of E. brunetti was found to be against sexual reproduction. Effects similar to those noted in vivo were seen with E. tenella and E. brunetti growing in tissue culture. Occasional schizonts of E. tenella under the influence of drug were able to produce a peripheral array of merozoites surrounding a multinucleate residual mass. In contrast to the situation in vivo, with drawal of drug from tissue cultures infected with E. tenella allowed the further development of some inhibited parasites. E. necatrix responded to the azauracil derivative in a manner similar to E. tenella.
The importance of parasite mortality in regulating the population size of the AcanthocephalanPomphorhynchus laevisin goldfish
Authors: Kennedy C. R.
Published: June 2009

Experiments to study the mortality rate of the acanthocephalanPomphorhynchus laevisin goldfish are described. Infections with different population densities of parasite were given to fish on one occasion only and on several occasions with different time intervals between infection.

The parasites established and grew in the experimental hosts at rates comparable to those in natural hosts on all occasions. The proportion establishing did not decrease with increasing population size and bore no relationship to the presence of an existing infection. The greatest loss of parasites occurred during the period of establishment. Thereafter, mortality was gradual, and the proportion of the population lost was not related to either the density of infection or to the intervals between infections. No evidence of reduced growth rate was found at the higher population densities.

It is concluded that parasite mortality does not function as a feedback control and so is relatively unimportant in regulating the population size of fish acanthocephalans. Both field and laboratory evidence indicate that this is controlled by factors influencing recruitment. The equation of mortality and recruitment rates observed in many field populations must therefore be a matter of chance, and the implications of this with respect to the stability of fish-acanthocephalan systems is discussed.