bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on a virus found in the roots of certain normal-looking plants
Authors: Smith Kenneth M. 
Published: June 2009

An account is given of a virus which is present in the roots of a number of different plants. Plants which have been shown, so far, to contain the infective principle in the roots are several members of the Solanaceae, tomatoes, tobacco, etc.; of the Primulaceae, Polyanthus sp. and Primula obconica; of the Geraniaceae, zonal Pelargonium; and of the Compositae, the aster. Such plants show no indication of infection with the exception of Nicotiana tabacum and N. glutinosa, which may develop natural disease symptoms. These symptoms are usually confined to the two lowermost leaves and develop most frequently under conditions of low temperature and low light intensity. The virus never becomes completely systemic in any host plant and is generally restricted to the inoculated leaves. Experiments are described which show the virus to be present in the roots of tobacco plants which had given a negative virus reaction a few weeks earlier. The virus is found in the roots of tobacco plants arising from seed which has been heated to a temperature of 75° C., the thermal death-point of the virus in expressed sap being 72° C. All attempts to demonstrate the presence of the virus in the seed have proved negative.Although no systematic study has been made, the range of plants susceptible to local infection in the leaves, by artificial inoculation, seems wide. Tests have shown that about 25 species of plants belonging to 10 families respond to inoculation with the virus.Three possible explanations of the origin and spread of the infection are discussed.
The life history and pathogenicity of Eimeria meleagridis Tyzzer, 1927, in the turkey poult
Authors: Clarkson M. J. 
Published: June 2009

A description is given of the life history and pathogenicity of a species of Eimeria, derived from a single oocyst infection in a coccidia-free bird, and subsequently identified as E. meleagridis.There are two asexual generations followed by the sexual generation. The first schizogony cycle occurs in the small intestine and the second and sexual generations are restricted to the caeca.The organism is not pathogenic but the sexual stages produce marked caseous lesions in the caeca. It is immunologically distinct from a pure strain of E. adenoeides and cannot be transmitted to chickens.
Seasonal variations in the incidence and development of the cestodeProteocephalus filicollis(rud. 1810) inGasterosteus aculeatus(L. 1766)
Authors: Hopkins C. A. 
Published: June 2009

1. The incidence, intensity of infection, rate of growth and genital development inProteocephalus filicollishas been studied by the monthly examination of approximately 60Gasterosteus aculeatusover a period of 2 years.2. The existence of an annual cycle, commonly reported for cestode parasites of fish in a temperate climate, is clearly established. The most advanced stages commonly occurring are: plerocercoids (0·25–5mm.) July-November; strobilate worms with genital primordia (58mm.) December-April; mature worms (1 cm.) April-May; gravid (2 cm.) June-July.3. No tissue phase occurs between the time the procercoid is swallowed and the mature worm develops, but there is a migration from the rectum to the anterior part of the intestine.4. From a consideration of the seasonal variation in incidence it is deduced that the parasitic population is in dynamic balance and that approximately 1 % of worms present are lost daily.5. No evidence to support the existence of immunity was found. The lower incidence in 1+ than in 0+ fish was attributed to feeding habits.6. Other aspects discussed are the interrelationship of proglottid formation and appearance of genital rudiments; the structure of the egg-shell; and the intensity of infection ofCyclopswith procercoids as calculated from the numerical distribution of worms in the fish host.7. Reference is made to intercurrent helminth and protozoan infections and the effect of an epidemic ofIchthyophthiriussp. on the fish population.I wish to thank Prof. C. M. Yonge for granting every facility for this work. My thanks are also due to Mr Archer, Miss Bell, Mr Berrie, Miss Spence and Miss Wyllie for help in collecting fish, and to Mr Gray who showed me the lochan.
Anthelmintic studies: III. A taeniacidal testing technique
Authors: Steward J. S. 
Published: June 2009

1. A controlled taeniacidal technique is described using mice artifically infected with Hymenolepis nana var. fraterna.2. The method of interpretation is based upon a form of computation relating to the number and sizes of worms left in the treated animals as well as the proportion of mice rendered negative by the treatment as compared with untreated controls.
The identification and estimation of acetylcholine in three parasitic nematodes (Ascaris lumbricoides, Litomosoides carinii, and the microfilariae of Dirofilaria repens)
Authors: Mellanby Helen 
Published: June 2009

1. Extracts made from whole nematode worms, Litomosoides carinii, and from Ascaris ‘heads’ and body wall tissue, contain a substance similar to acetylcholine.2. In the case of extracts from Litomosoides whole worms, this substance was shown to be probably acetylcholine itself.3. Tissue from the anterior end of Ascaris (including the nerve ring), contains about 15 times as much acetylcholine as the body wall preparations; i.e. 0·39μg./g. as compared with 0·025μg/g. of wet weight.4. There appeared to be rather more acetylcholine present in the Litomosoides males than in the females; 0·92μg./g. as compared with 0·63μg./g. of wet weight.5. The microfilariae of the filariid nematode of the dog, Dirofilaria repens, contain as much as 2·4;μg./g. of acetylcholine. In this respect it resembles some other motile parasites of the blood, such as trypanosomes.
Excystment and in vitro cultivation of Echinoparyphium serratum
Authors: Howell M. J. 
Published: June 2009

Seventy-five per cent of Echinoparyphium serratum metacercariae excysted within 10 min in a trypsin/sodium cholate solution after successive pretreatments with pepsin and sodium dithionite. Excystment appears to be an active process as the cyst wall is unaffected by the treatment except in the vicinity of the ‘escape aperture’.Optimum development to sexual maturity in vivo required 72 h and was divided into six easily recognized stages against which development in vitro could be judged. These were undifferentiated (excysted metacercariae), cell multiplication, organogeny, gametogeny, vitellogenesis and oviposition. Migration of the juveniles from the lower regions of the intestine to the duodenum in the first few hours after infection was noted.Cultures were prepared from excysted metacercariae and a variety of media were used. The beneficial effects of shaking cultures were apparent. No development took place in media containing saline, Parker 199 medium, homologous and heterologous sera, chicken embryo extract, albumen and glucose, either alone or in various combinations, although, relative to saline or Parker 199 medium controls, survival times were increased in some and decreased in others. Survival in some media above pH 7 was longer than below pH 7. Serum substrates in culture vessels, and the presence of additional glucose, did not increase longevity.Development to organogeny was achieved using a yolk/albumen/saline or 199 medium, and addition of yeast extract to this favoured the later stages of development up to and including vitellogenesis. In general only a small percentage of juveniles in each culture reached vitellogenesis, and the amount of egg-shell protein formed and the size of the worms was always less than in vivo. Furthermore, development in vitro was much more prolonged than in vivo. Variability in development in vitro may be due to failure of the excystment procedure to satisfy completely the physiological ‘triggers’ which are probably necessary for normal development.In some specimens vitellogenesis was reached without production of sperm. In others, production of eggs was thought to be inhibited by either a general deterioration of the juveniles or premature ‘tanning’ of the egg-shell protein, as significant amounts of egg-shell protein, sperm, and apparently normal ova were present.The results of culturing E. serratum are compared briefly with those of D. phoxini.I should like to record my sincere thanks to Professor J. D. Smyth for his advice and comments on the manuscript.
Lymnaea natalensis laboratory culture and production of Fasciola gigantica metacercariae
Authors: Bitakaramire P. K. 
Published: June 2009

A method of breeding and maintaining L. natalensis cultures in the laboratory is described.The infection of snails with F. gigantica miracidia and the collection of metacercariae is discussed. The mean number of metacercariae arising from cercariae produced by each snail was 652·6, over a period of 8·2 days.It is shown that after 3 months storage F. gigantica metacercariae are still viable when excysted in vitro by using artificial pepsin and trypsin enzymes.The author wishes to express his thanks to Dr G. M. Urquhart of the Wellcome Laboratories for Experimental Parasitology, University of Glasgow, Veterinary Hospital, Bearsden Road, Bearsden, Glasgow, who has read through this paper and made the necessary corrections.
Experiments on the Action of Emetine in Cultures of Entamoeba Coli.
Authors: Bishop Ann 
Published: June 2009

1. Two pure strains of Entamoeba coli, differing in their accompanying bacterial flora and experimental history, but identical morphologically, have been tested with emetine hydrochloride in vitro.2. In a buffered and wholly liquid medium, with a pH varying between 6·8 and 7·2, emetine hydrochloride was found to be toxic to E. coli in dilutions between 1 : 300,000 and 1 : 600,000, the toxicity increasing with the alkalinity of the medium.3. It is therefore concluded that emetine is about 16 times as toxic in vitro to E. histolytica as it is to E. coli.
A comparison of malarial antigens from human and Aotus monkey blood infected with Plasmodium falciparum
Authors: Wilson R. J. M. , Voller A. 
Published: June 2009

An extract of blood from Aotus monkeys infected with Plasmodium falciparum contained all the clones of malaria precipitins so far identified in human blood.We are grateful to the Medical Research Council and Overseas Development Administration of Great Britain and to the World Health Organization for their financial assistance.
The distribution and abundance of the ectoparasites of the wild rabbit, Oryctolagus cuniculus (L.), in New South Wales, Australia
Authors: Williams R. T. 
Published: June 2009

In the winters of 1969 and 1970 a total of 64 rabbits was shot at 11 sites covering diverse climatic regions in the western, central and eastern districts of New South Wales. The ectoparasites of these rabbits were identified and counted. The flea Echidnophaga myrmecobii was most frequently found in western districts; the louse Haemadipsus ventricosus was prevalent in the central districts; the mite Listrophorus gibbus was very abundant on rabbits from the eastern districts, whilst the mite Cheyletiella parasitivorax was prevalent on rabbits from central and eastern districts.The probable consequences of these variations are discussed in relation to their possible effects on the epidemiology of myxomatosis.This investigation was carried out as part of the study of the biology of the wild rabbit undertaken by the Division of Wildlife Research, CSIRO, under the general supervision of Mr K. Myers. The author is indebted to P. Haycock and Miss S. Stephens for invaluable technical assistance. Messrs I. Parer, M. Stranger, G. Richards, H. Bults, J. Libke and P. Haycock shot the rabbit samples.
The effect of cortisone on the worm burdens of calves infected daily withOstertagia ostertagi
Authors: Michel J. F. , Sinclair I. J. 
Published: June 2009

Of two groups of calves, one was regularly treated with the cortisone-derivative, β-methazone. This treatment greatly reduced the ability of the calves to produce antibody and gave rise to a number of side effects. Calves of both groups were given 1500 infective larvae ofOstertagia ostertagidaily. A milder régime of cortisone administrations using prednisolone was employed in a second experiment in which two comparisons were made. Worm burdens of calves infected with 1500 larvae daily and receiving cortisone were compared with those of control calves infected at the same rate and cortisone-treated calves receiving 1500 larvae per day were compared with cortisone-treated calves infected at twice this rate.By periodicpost-mortemexamination it was shown that even in cortisone-treated animals the worm burden was regulated at a level only slightly higher than in control calves, apparently by a density-dependant loss of worms. A more rapid loss of worms which occurred for a period in the control calves was prevented in cortisone-treated animals unless the infection rate was high.The limit set by the normal host to the total egg output of its worm population was raised by cortisone treatment, very greatly in the first experiment, rather less in the second in which the cortisone treatment was less severe. The effect of host resistance on the length of worms and on the incidence of females without vulval flaps was greatly reduced by cortisone. The inhibition of development was not affected.
The use of parasympathomimetic drugs to stimulate salivation in the tick Rhipicephalus appendiculatus, and the transmission of Theileria parva using saliva obtained by this method from infected ticks
Authors: Purnell R. E. , Branagan D. , Radley D. E. 
Published: June 2009

Various parasympathomimetic drugs were injected per anus into female R. appendiculatus, previously fed for 5 days on rabbits, in attempts to induce the ticks to salivate. Pilocarpine nitrate and arecoline hydrobromide gave the best results and these drugs were therefore injected into ticks of various weight ranges and at various concentrations of the drug and the diluent, saline. The drugs were most effective at a concentration of 10% in 6% sodium chloride solution. If ticks salivated, the amount of saliva they produced could be positively correlated with their weight.Sections of salivary glands from 5-day-fed female ticks in the corresponding weight ranges were examined for infection with T. parva. There appeared to be an inverse relationship between the infection rate of the ticks, and the number of infected acini observed, with increase in their weight. It was established that the greatest numbers of infective particles of T. parva should be obtained by the injection of 1 μl of 10% pilocarpine nitrate in 6% sodium chloride solution into ticks weighing between 3.1 and 13.0 mg. Twenty-five infected ticks in this weight range were injected, and the resultant saliva added to concentrated autologous leucocytes in phosphate-buffered saline before injection into a steer. The animal underwent a typical East Coast fever reaction and died, thus indicating that infective particles had been harvested by our methods.Acknowledgements are due to many colleagues for assistance in a variety of ways. Mr M. P. Cunningham, Mr C. G. D. Brown, Dr J. K. H. Wilde, Dr R. Tatchell, Mr M. L. Burdin and Dr G. H. Freeman have given us a great deal of helpful advice. Mr C. Boarer and Mrs D. Backhurst supervised and carried out the processing and staining of the tick sections. Mr B. Wood carried out the weighing of the ticks and prepared the photographs.
‘Host’ antigens associated with schistosomes: observations on their attachment and their nature
Authors: Clegg J. A. , Smithers S. R. , Terry R. J. 
Published: June 2009

Further investigations have been carried out on the nature of ‘host’ antigens associated with the adult worms of Schistosoma mansoni. These investigations show:1. The ‘host’ antigens are not removed from the surface of the worms by thorough washing and prolonged incubation in Hanks's balanced salts solution. The antigens must be firmly bound or even incorporated at the surface.2. Monkeys cannot be immunized against ‘mouse worms’ with mouse IgG immunoglobulins. Accordingly it is unlikely that the ‘host’ antigens are mouse anti-worm antibodies.3. The ‘host’ antigens are certainly associated with the membranes of mouse erythrocytes. They may also be associated with the ‘soluble protein’ fraction of the erythrocytes.4. Immunization with sheep erythrocytes failed to protect monkeys against challenge with ‘mouse’ worms. Therefore it is unlikely that the ‘host’ antigens are Forssman antigen.5. The mouse ‘host’ antigens associated with ‘mouse’ worms are not major histocompatibility antigens. Consequently it is likely that they are species-specific mouse antigens.
In vitro cultivation of Echinococcus granulosus, Taenia hydatigena, T. ovis, T. pisiformis and T. serialis from oncosphere to cystic larva
Authors: Heath D. D. , Smyth J. D. 
Published: June 2009

A technique for the hatching and subsequent in vitro cultivation of the oncospheres of Echinococcus granulosus, Taenia hydatigena, T. ovis, T. pisiformis and T. serialis to cystic larvae is described. The cytology and histology of developing larvae were also studied.The basic culture medium consisted of medium 858 containing additional glucose and K+ supplemented with the appropriate host sera. Fresh sera from young animals was generally more successful in promoting growth than sera from commercial sources. Cultivation was carried out at 37°C in roller tubes with a gas phase of 10% O2+5% CO2 in N2.The most successful results were obtained with T. pisiformis, oncospheres of which were grown to the cystic stage with development of hooks and suckers. During the later culture period, the bladder, although morphologically normal, ‘collapsed’ and did not retain its cystic shape.In culture, larvae of T. pisiformis became motile at 3 days and at 5 days began secreting droplets from a glandular apical region; this region stained differentially in alcian blue.Some larvae of T. pisiformis showed a tendency to undergo transverse or longitudinal fission, an effect possibly associated with the centrifugation applied during the early cultivation procedures.Early cystic development was obtained with the other species studied, but experiments carried out were only of a preliminary nature. However, the development rate in these experiments approximated that recorded in vivo.
Experimental concurrent infections with Strongyloides ratti and S. venezuelensis in laboratory rats
Authors: Wertheim Guta 
Published: June 2009

The distribution of S. ratti and S. venezuelensis in the intestine of albino rats was studied in experiments with single species infections and in mixed infections.The majority of S. ratti were found in the anterior 20 cm of the intestine and in decreasing numbers in the remaining 60 cm. The larvae of S. ratti settled in the Lieberkühn crypts where they matured and laid eggs in convoluted tubes.The parasitic females of S. venezuelensis were concentrated in the anterior 15 cm of the intestine, with over 50 % in the anterior 5 cm, and a few worms 20–25 cm posterior to the pylorus. The larvae settled in the villi, close to the surface of the mucosa. The straight egg strands were laid on this site.It was concluded that, although occurring together, the two species can coexist in the intestine without interfering with each other.
Analysis of antigenic types appearing in first relapse populations of clones of Trypanosoma brucei
Authors: Miller E. N. , Turner M. J. 
Published: June 2009

SUMMARYVariant antigenic types (VATs) represented in a total of 47 first relapse populations of 6 clones of Trypanosoma brucei LUMP 227 were identified by immunofluorescent staining of living trypanosomes, using antiserum raised against purified surface antigens. The relative growth rates of these 6 clones were measured both individually and when grown together in a mixed population, and were found to be different under these two sets of conditions. A pattern emerged in the VATs represented in relapses of each clone, with some types being expressed more frequently than others and certain VATs being only very rarely expressed. It is suggested that new VATs are expressed according to a statistically definable order of priority which is different for each parent VAT, and that some VATs may be able to change to certain others only after passing through an intermediate VAT. The order of priority of appearance of VATs does not appear to correlate with growth rate measured either in individual clones or when clones are grown in a mixed population.
Mites of the hedgehog Erinaceus albiventris Wagner in Kenya: observations on the prevalence and pathogenicity of Notoedres oudemansi Fain, Caparinia erinacei Fain and Rodentopus sciuri Fain
Authors: Gregory M. W. 
Published: June 2009

SUMMARYThe occurrence of 3 mites (Acari: Astigmata) is reported, from the Central African hedgehog Erinaceus albiventris Wagner, in the Nairobi area of Kenya. Notoedres oudemansi Fain (Sarcoptidae) showed sporadic incidence, affected males particularly and caused high mortality. A description of the male mite is given. Caparinia erinacei Fain (Psoroptidae) was found on 72% of animals on capture but showed very low pathogenicity. Rodentopus sciuri Fain (Hypoderidae) was found in the hair follicles of 46% of 43 animals examined; adverse effects were slight.
Scanning electron microscopy of the duodenal mucosa of chickens infected with Eimeria acervulina
Authors: Michael E. , Hodges R. D. 
Published: June 2009

The morphology of the duodenal mucosal surface of chickens infected with Eimeria acervulina has been studied on days 5, 6, 8 and 11 post-infection and compared with that of the normal duodenal mucosa using the scanning electron microscope. The normal duodenum possessed tall, spatulate villi with horizontally-arranged surface clefts upon which a regular pattern of hexagonal absorptive cells and goblet cell mouths was superimposed.A maximum degree of villous atrophy was shown on day 5 post-infection, the villi being thickened and flattened with frequent adhesions and fusions between them. The general effects of the disease together with the physical presence of intracellular parasites caused considerable changes in size and shape of the cell apices. By day 8 the mucosa was clearly recovering, with a normal pattern of somewhat thickened and truncated villi beginning to re-appear and by day 11 post-infection the mucosa had regained an outwardly normal morphological pattern. The mucosal changes are discussed in relation to similar changes which occur in diseases of the alimentary tract of other animals, including man.