bluuebunny/crossref_metadata_2025_split huggingface dataset:
The growth of Trypanosoma cruzi in human diploid cells for the production of trypomastigotes
Authors: Sanderson C. J. , Thomas Jennifer A. , Twomey Cheryl E. 
Published: June 2009

SummaryThe use of human diploid cell lines of finite life for the in vitro production of Trypanosoma cruzi is described. Both MRC5 and WI38 cells release trypomastigotes with less than 5% amastigotes. This could form the basis for biochemical and immunological studies, which were previously limited by the problems of separating parasites from blood. By selecting the in vitro passage number of the parasite it is possible to select for either the broad or the slender forms of trypomastigotes, allowing comparative studies of these forms within a single strain of the parasite. It is also possible to isolate amastigotes by disrupting the cells before trypomastigotes appear, and separating them from cell debris with Metrizamide. It is shown that by incorporating [3H]uridine in the cell-culture medium, labelled trypomastigotes are obtained. The release of this label (putative RNA) provides a relatively simple isotopic assay for parasite death. Examples of this assay for testing drug toxicity and in immunological lysis are presented.
The response of Awassi sheep to re-infection with Haemonchus contortus larvae
Authors: Altaif K. I. , Al-Abbassy S. N. , Abboud H. B. 
Published: June 2009

SummaryThe response of Awassi sheep to primary infection with 10000 Haemonchus contortus larvae and subsequent challenge with 20000 larvae was studied. Two types of response to re-infection were observed. The first, characterized by a sharp decline in egg counts, progressive improvement in packed cell volume (PCV) and a marked loss of adult worms and challenge larvae, was considered as self-cure and protection. In the second type of response there was a temporary decline in egg counts, no improvement in PCV and necropsy findings indicated hyperinfection with challenge larvae.
The structure and possible function of the ventral papillae of Notocotylus attenuatus (Rudolphi, 1809) Kossack, 1911, (Trematoda: Notocotylidae)
Authors: Radlett A. J. 
Published: June 2009

SummarySpecimens of Notocotylus attenuatus were examined in life and their ventral papillae studied by scanning and transmission electron microscopy. It was found that the papillae are non-secretory, very mobile and similar in ultrastructure to the papillae of other notocotylids previously described. Worms were removed from the host's caecum and the caecum surface examined where it had been in contact with the papillae; this revealed that the crypts in this region had been distorted and enlarged. It is suggested that the papillae serve to attach the worms to the distinct surface of the distal caecum by acting as hydraulically operated anchors working in conjunction with the lateral margins of the worm and allowing the oral sucker of this monostome fluke to be used for feeding.
Isolation of second-generation schizonts of avian coccidia and their use in biochemical investigations
Authors: James S. 
Published: June 2009

SummaryA technique is described for the isolation of a pure suspension of second-generation schizonts ofEimeria necatrixandE. tenella. Most of the schizonts appeared viable as judged by their ability to exclude Trypan blue and the use of this criterion is examined. They were able to metabolize radio-isotope labelled glucose and accumulate thiamine against a concentration gradient. A formula allowing detailed consideration of the latter process is introduced. Crude extracts of these schizonts exhibited serine hydroxymethyl transferase activity which is significantly different from that of the host tissue in terms of optimal pH (8·3 for the parasite and 7·8 for the avian intestinal cells) and Michaelis constant (approximately 2·6 × 10−3mand 0·6 × 10−3mrespectively). Differences in response to potential inhibitors are also shown.
Antigenic variation in trypanosomes: a computer analysis of variant order
Authors: Kosinski R. J. 
Published: June 2009

SummaryAfrican trypanosomes can undergo antigenic variation and evade the host immune response. Whether the antigenic variants arise in an ordered sequence or randomly has been in dispute but has not been statistically tested. The coefficient of concordance (W), a statistic designed to detect similarities between sequences of objects, was applied to the literature data. The tendency towards a reproducible order of variants was strong, although in several of the studies the number of experimental animals was so low that no conclusions could be drawn. A computer model was used to determine whether this degree of order could arise with random generation of variants followed by selection. The model simulated a trypanosome clone with 90 possible variants, widely differing variant-specific growth rates, random variant origin and variant eradication by an anamnestic host immune response. Parameters varied were maximum parasitaemia, growth rate differential between ‘fast’ and ‘slow’ variants, and parasitologist ability to detect minor variants. Random generation and selection by growth rate alone could not produce the degree of variant orderliness reported in the literature. However, experiments with larger numbers of host animals and direct investigation of variant growth rates and competitive interactions are necessary before the random generation-selection hypothesis can be proven or disproven.
Further Experiments upon the Drug Treatment of Canine Piroplasmosis
Authors: Nuttall George H. F. , Hadwen S. 
Published: June 2009

1. Trypanblau injected subcutaneously into dogs a day before or a day after they have been inoculated with blood containing Piroplasma canis effectually prevents the development of piroplasmosis by destroying the parasites at the onset of infection.2. Trypanblau given by the mouth is ineffective, since it exerts no apparent influence either upon the parasite or upon the course of the disease.3. Tryparosan, when injected subcutaneously or when given by the mouth, has no effect upon the parasite and is ineffective as a remedy against piroplasmosis in the dog.
Notes on Nagana and on Some Haematozoa observed during my travels
Authors: Durham Herbert E. 
Published: June 2009

1. Some cases of remarkable resistance to nagana infection are recorded.2. Although such birds as pigeons are unable to harbour the trypanosoma brucei, the kestrel is able to do so.3. Attention is drawn to certain changes which are brought about by the trypanosome infection and the need for more precise chemical investigation of these haematozoal diseases.
Notes on certain points in the Cytology Of Trypanosoma raiae and Bodo caudatus
Authors: Robertson Muriel 
Published: June 2009

1. T. raiae and Bodo caudatus are investigated using Feulgen's nucleal reaction in addition to the usual nuclear stains. The nature and value of this method is discussed.2. In T. raiae the parabasal body or kinetonucleus is found to consist of chromatin as shown by the nucleal reaction. An achromatic element in its composition is suggested in the division by the desmose between the two halves being achromatic.The blepharoplast is an achromatic structure. It seems probable that it persists in the aflagellar phase of the trypanosome. In T. raiae the division of the blepharoplast precedes but does not apparently orientate the division of the parabasal body. The division of the parabasal body does not present a mitotic figure.3. The nucleus in T. raiae consists of an achromatic karyosome body with some chromatin surrounding it, there is also chromatin arranged upon the inner surface of the nuclear membrane.4. At division the karyosome apparently draws out into an achromatic spindle figure, the chromatin collects in the prophase into a loose granular mass and then becomes arranged at the equator. The mass divides into two portions; it is not possible to distinguish chromosomes with sufficient certainty. The nuclei are finally reconstructed from the achromatic ends of the spindle and the chromatin which has travelled to either pole.5. In Bodo caudatus the parabasal body (kinetonucleus) is composed of chromatin and of an achromatic substance, the blepharoplasts or basal granules are achromatic bodies which play an orientating part in the division of the parabasal body: this division does not show an equatorial plate stage. The nucleus is made up of an achromatic nucleolus-karyosome surrounded by a hollow sphere of chromatin; there is a very definite division process which takes place apparently within the nuclear space. There is no equatorial plate formed and the achromatic figure which is derived directly from the karyosome is a division column which inserts itself into the already dividing chromatin and is not of the spindle fibre type found in the mitosis of the metazoan cell and of many protozoa.
Warble Flies. A Further Contribution on the Biology of Hypoderma lineatum and Hypoderma bovis
Authors: Hadwen Seymour 
Published: June 2009

The experiments with warble-fly larvae, taken in conjunction with the evidence of Carpenter and Gläser, lend support to the view that they gain an entrance through the skin.The hypothesis is advanced that the larvae select the gullet for reasons connected with their development and growth. These may be: a freer supply of oxygen, and a loose areolar tissue which offers comparatively little resistance to them.The position of the larva under the hide is horizontal. In this position the skin movements affect it but slightly, or less than if the position were perpendicular.H. lineatum does not terrify cattle as does H. bovis, the fly was seen ovipositing and the animals showed little uneasiness during the process.The seasonal activity of H. lineatum is earlier than that of H. bovis.Observations were made on oviposition which confirmed those of Riley and Gläser.Two experiments were tried with larvae, to see if they would penetrate the hide, but no definite results were obtained.Further proof is afforded of the terror which H. bovis inspires in cattle. It was observed that animals, exhausted by running, occasionally lay down and became more or less indifferent to the attacks of the fly. On these occasions the eggs were laid higher up on the host's body.
The larval stages of the celery fly (Acidia heraclei L.) and of the braconid Adelura apii (Curtis), with notes upon an associated parasitic yeast-like fungus
Authors: Keilin D. , Tate P. 
Published: June 2009

The larval stages of the celery fly, Acidia heraclei, have been described, and it is shown that this larva agrees with other biontophagous dipterous larvae in having the pharynx devoid of ventral ridges. The transparency of the larvae permits the internal anatomy to be seen clearly in the living larva, and by this means the structure of the perispiracular glands is clearly revealed.The braconid Adelura apii occurs as a parasite of Acidia heraclei larvae, and its first. stage larva is described in detail. This larva is densely hairy, has a long, curved, hairy, tail-like appendage and, by the more rapid growth of the ventral surface, it develops a dorsal curvature which obscures the true orientation so that the true dorsal surface appears externally to be ventral. In these respects the first stage larva of Adelura apii resembles that of A. gahani described by de la Baume-Pluvinel. The later larval stages of A. apii, of which there are at least two, are naked, lack the tail-like appendage and do not differ from the normal type of parasitic hymenopterous larvae.A yeast-like fungus occurs as a parasite in the blood of Acidia heraclei larvae. It is always found associated with existing or abortive infection of the larvae with Adelura apii. Dense mycelial masses sometimes occur in the gut of A. apii pupae and are probably derived from the yeast cells parasitic in the host larvae. It is suggested that this is a unique case of a fungus parasitic in a host larva (Acidia heraclei) undergoing part of its development in a parasitic braconid (Adelura apii), adult females of which transmit the fungus to the host larva during oviposition.
Biology, morphology and anatomy of aphidophagous syrphid larvae
Authors: Bhatia Madan Lal 
Published: June 2009

The paper deals with the biology, morphology and anatomy of seven species of syrphid larvae viz.Syrphus lunigerMeig.,S. balteatusDe Greer,S. ribesiiLinne,Catabomba pyrastriLinne,Sphaerophoria flavicaudaZett.,Sph. scriptaLinne, andPlatychirus scutatusMeig.The habitat, mode of progression, aphidophagous habits and characteristic coloration are described for each species.It is shown that the larvae of all the above species, like larvae of other cyclorrhaphous Diptera, definitely pass through three stages separated by two moults. The mode of dehiscence of the puparium is described briefly.Each of the species, exceptCatabomba pyrastri,has three generations in the breeding season which lasts from May to October.Platychirus scutatushibernates only in the larval stage, but the other species may be found in both the larval and pupal stages during the winter.The larvae of all the above species, exceptSyrphus balteatus,are commonly parasitized by ichneumonid larvae.The morphology of the egg, the three larval stages and the puparium ofS. lunigeris described in detail.The characters common to the third stage larvae of all the species dealt with are summarized and short descriptions of the third stage larvae and puparia of the individual species are given. The general appearance of the living larvae and details of the buccopharyngeal armature, spiracles and puparia of each of the species is represented in figures.In connexion with the pupae a number of new structures are described and it is suggested that some of them are concerned with the formation of the characteristic shape of the puparium and with the dehiscence of the puparium.Internal pupal spiracles are present in all the species dealt with, but external pupal spiracles are present only inPlatychirus scutatus.The anatomy ofP. scutatusis described and figured, an account being given of all the structures except the musculature of the body wall. Study of the anatomy affords evidence as to the carnivorous mode of life of the larvae and also indicates that the larvae have evolved from aquatic forms.The comparative morphology of the Syrphinae is discussed with respect to the relationship of the Syrphinae to other Aschiza and to the cyclorrhaphous Diptera.
Some Common Queensland Mosquitoes as Intermediate Hosts of Wuchereria bancrofti (Filaria bancrofti)
Authors: Heydon G. M. 
Published: June 2009

1. Anopheles amictus in North Queensland is a favourable intermediate host for Wuchereria bancrofti, comparable but perhaps not quite equal to Culex fatigans. The two described varieties of A. amictus were both tested.2. Experiments with Aëdes vigilax and Culex sitiens show that the former is a rather poor host and the latter a very poor one though infective larvae develop in some mosquitoes.3. In experiments with Aëdes argenteus none of the sixty-two mosquitoes used proved hospitable.4. Some observations on the transmission of filariasis in New Britain and on mosquitoes there are mentioned.
Some points relating to the Morphology and Development of Sarcocystis tenella
Authors: McGowan J. P. 
Published: June 2009

A short description is given of an important disease of sheep (Scrapie, Traber-krankheit, La Tremblante), believed to be caused by a heavy infection with Sarcocystis tenella, probably of increased virulence.The itchiness and paresis, the congenital transmission by the mother, the non-contagiousness, the long incubation period, etc., are readily explained on this view and a method of control of the disease based on this theory has been highly successful.The sarcocyst has been shown to be transmitted from sheep to sheep by intrauterine infection and by means of the milk.The minute structure of the sarcocyst is described and it has been shown in particular that the sickle-shaped spores are surrounded by a capsule. Under certain conditions, as in 1 per cent, glucose water and in the centre of the ripe cyst, these spores swell out and become globular, eventually bursting and scattering small chromatin granules. The further evolution of these granules is dealt with.The spread by means of milk and by the intestinal route is discussed1.
Fertility in the argasid tick, Ornithodorus moubata, Murray
Authors: Robinson G. G. 
Published: June 2009

The fertility rate of eggs of the tick, Ornithodorus moubata, was investigated with the following results:(1) Although three batches of eggs can be laid after a single mating, fertility is considerably improved if a fresh mating take place before each oviposition.(2) Fertility of the eggs decreases with the interval between mating and oviposition (the latter takes place usually only after a blood meal).(3) If the organ of Géné is faulty (permanently everted) none of the eggs will develop.(4) Eggs have a wide tolerance of temperature, and show no alteration in fertility rate from 22 to 32° C. At 34° C. no larvae are produced at all.(5) Females lay over twice as many eggs in sand as they do on a flat surface such as filter paper.
An experimental study of East Coast fever in Uganda IV. A study of the East Coast fever reactions produced when infected ticks 171 days old were fed on susceptible calves in limited numbers over a period of 3 weeks
Authors: Wilson S. G. 
Published: June 2009

This experiment showed that infections of Theileria parva were still viable in nymphae of Rhipicephalus appendictdatus 171 days old, but when nine nymphae were fed on calves at intervals over 22 days the reactions produced were most irregular.In group A reactions varied from acute fatal type to mild, doubtful or no obvious reaction. None of the four animals which survived was protected from subsequent infection when grazed in a tick-infested paddock (Table 1). The two fatal reactions which developed in this paddock varied in intensity; calf no. 5717 showing a typical acute East Coast fever reaction, but the reaction of calf no. 167 showed several atypical features especially in the sporadic appearance of Koch's bodies.In group B the reactions were again in marked contrast to those seen in group A, one fatal reaction developed and only mild transient reactions without the production of Koch's bodies were seen in the remaining five calves. These mild reactions, however, appeared to be sufficient to protect against subsequent re-infection in the tick-paddock (Table 4).It is doubtful if the transient reactions seen in calves nos. 5734 (on the 12th day), 172 and 168 could be diagnosed clinically under field conditions, and further investigations as to the infectivity of these types of reactions are required.In calves nos. 165 and 167 Koch's bodies were absent from all tissue smears at time of death, and diagnosis of the true cause of death by smears alone would therefore be difficult. Reactions such as those given by calves 133 and 139 cast further doubt on the ability to diagnose East Coast fever by gland-smear technique.In general, the results of this experiment appear to indicate that if the original reaction is mild a second reaction may develop within a few weeks with or without the production of Koch's bodies. The development of a durable resistance to further attacks may not, therefore, depend on the presence of Koch's bodies in the peripheral glandular tissues in detectable numbers.My thanks are due to the Director of Veterinary Services, Uganda, for his permission to carry out this work and to publish this paper.
On the longevity of fasting ticks, Hyalomma savignyi Gerv
Authors: Feldman-Muhsam B. 
Published: June 2009

The survival of fasting imagines of Hyalomma savignyi under various conditions of temperature and relative humidity was studied.Within the range of experimental conditions low temperature and high humidity are shown to be most favourable to the survival of ticks: at 17·5° C. and 80–95% R.H. mean longevity approaches 1 year, and a few individuals were observed to survive for more than 2 years. Longevity shortens as temperature rises and relative humidity decreases. At a temperature of 37° C. (and under various conditions of humidity) average longevity does not exceed 1·5–3·5 months, while under conditions of extreme dryness, viz. 10–20% b.h. (and various temperatures) average longevity ranges from 1·5 to 9 months.The longevity of fasting imagines is not as much affected by dryness as that of preimaginal stages.
The bionomics of Ixodes hexagonus Leach in Britain
Authors: Arthur D. R. 
Published: June 2009

1. Ixodes hexagonus is a three-host tick.2. The length of the pre-oviposition period is fairly constant at 19° C. in a saturated atmosphere, varying between 12 and 14 days.3. Oviposition takes place as in I. ricinus and, at room temperatures at 18–20° C., R.H. 100%, the number of eggs laid varies from 880 to 1449. Experiments on the effects of different temperatures and humidities on egg-laying are described.4. Eggs hatch in 52–59 days under the conditions stated above.5. The larvae gorge for 3–6 days, the majority becoming replete on the third and fourth days after attachment.6. The metamorphosis of the larva is prolonged by cold conditions and is hastened during warm weather. In a saturated atmosphere at 15, 20, 22 and 25° C., the mean times for moulting are respectively 60, 33, 27 and 23 days.7. The nymphs gorge for 5–7 days, the greater number dropping off between the sixth and seventh days.8. At 18° C. and 100% R. H. moulting of the nymph takes place about 32 days after repletion.9. After metamorphosis the adults rest for 8–12 days, and feeding lasts 8–16 days.
A method for studying the distribution and bionomics of trombiculid mites (Acarina: Trombidiidae)
Authors: Jones B. M. 
Published: June 2009

(1) The medical importance of trombiculid mites is indicated and reference is made to their geographical distribution.2. Methods used by investigators for assessing the distribution of the mites in the Far East are discussed as well as methods used in the study ofTrombicula autumnalis.3. A detailed account is given of a light-trap and the method of using it; the reaction of the mites to the trap is discussed.4. The results of a detailed survey are presented to show the significance of the method in relation to the distribution and bionomics of trombiculid mites.The main results of this survey are as follows:(a) The mites are characteristically distributed in pockets of infection.(b) A study of the ecoclimatic conditions favourable to mites shows that humidity is a limiting factor.(c) The free-living larval stage disappeared from the soil in October, and nymphs were found in the soil in September. These facts, together with the results of laboratory breeding experiments at room temperatures, which showed that it was normal for nymphs to appear in October, indicate that the nymphal and adult stages over-winter.(d) Mites are not associated with fruit bushes if the physical conditions of the soil are unfavourable. A tentative explanation is given to account for the frequent association of fruit bushes with miteirritation.(e) The gregarious habit of clustering is primarily due to a tactile response.5. It is concluded that the light-trap method offers a new approach to the problem of surveying an area in order to diagnose trombiculid mite infection. It is also of value in obtaining abundant material for laboratory investigations.
The systematic status of Ixodes percavatus var. rothschildi Nuttall & Warburton, 1911
Authors: Arthur D. R. 
Published: June 2009

1. The description of the female and nymph of the so-called variety I. percavatus var. rothschildi is enlarged.2. As far as the evidence is available it parasitizes marine birds and is probably a three-host tick.3. Its systematic affinities are discussed, and since I. percavatus is synonymous with I. auritulus, then the variety of Nuttall & Warburton should be raised to the specific rank of I. rothschildi.