Browsing by Author "Irvin, A.D."
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Item Adaptation and Possible Attenuation of Theileria Parva-Infected Cells Grown in Irradiated Mice(1976) Irvin, A.D.; Brown, C.G.D.; Stagg, D.A.; Kanhai, G.K.; Kimber, C.D.; Radley, D.E.; East African Veterinary Research Organisation, Muguga, P.O. Box 32, Kikuyu, KenyaTheileria parva-infected bovine lymphoid cells were taken from 8 cattle immediately after death from East Coast fever (ECF). Cells were inoculated into groups of irradiated Swiss and athymic nude mice. Cells became established in one group of Swiss mice and 2 groups of athymic mice. Development of cells in mice only occurred if cells concurrently established in culture; when establishment in culture was delayed, cells failed to develop in mice. Cells from one of the isolates in athymic mice were passaged 6 times through further mice. On inoculation of these mouse-passaged cells into cattle, the animals underwent mild reactions and subsequently resisted a lethal ECF challenge. The possibility of vaccinating cattle against ECF by means of mouse passaged cells merits further study.Item The Application of an Indirect Method of Infecting Ticks with Piroplasms for Use in the Isolation of Field Infections(1974) Cunninggham, M.P.; Purnel, R.E.; Ledger, M.A.; Irvin, A.D.; Brown, C.G.D.; Pyne, R.C.; East African Veterinary Research OrganizationNymphal R. appendiculatus ticks became infected with Theileria parva following the intraperitoneal inoculation of fresh or refrigerated infected bovine blood into rabbits on which the ticks were feeding. The method was successfully used in the isolation of field infections and as blood is the only material needed from such cases the method can be readily and conveniently applied in the isolation of different field strains of T. parva and possibly of similar blood-borne protozoal diseases.Item Attempted Transmission of Theileria gorgonis, Brocklesby & Vidler 1961, from Blue Wildebeest (Connochaetes taurinus) to Cattle(Tropenmed Parasitol, 1973) Purnell, R.E.; Schiemann, B.; Brown, C.G.; Irvin, A.D.; Ledger, M.A.; Payne, R.C.; Radley, D.E.; Young, A.S.; Immunological Research on Tick-borne Cattle Diseases and Tick Control Project; East African Veterinary Research Organisation, MugugaFour blue wildebeest (Connochaetes taurinus), two from the Serengeti National Park in Tanzania and two from the Athi/Kapiti Plains m Kenya, were splenectomied. Of the two wildebeest from Tanzania, one which had previously had detectable intra-erythrocytic piroplasms of Theileria gorgonis, had an increase in parasitaemia to a peak of 7%, the other, which had previously had no detectable parasites, developed a low-level parasitaemia. The two wildebeest from Kenya had severely exacerbated T. gorgonis infections all in one case a concomitant Anaplasma marginale infection They died of severe anaemia after febrile responses and theilenal parasitaemias in excess of 70%. Attempts to transmit T. gorgonis to spienectomised calves by blood passage and to steer~ via Rhipicephalus appendiculatus ticks failed despite the establishment of the parasite in the ticks. A. marginale, on the other hand, was blood-passaged to two of the splenectomised calves, which were inoculated with blood from the infected wildebeest.Item Attempted Transmission of Theileria Gorgonis, Brocklesby & Vidler 1961, From Blue Wildebeest (Connochaetes Taurinus) to Cattle(1973) Purnell, R.E.; Schiemann, B.; Brown, C.G.D.; Irvin, A.D.; Ledger, M.A.; Payne, R.C.; Young, A.S.; East African Veterinary Research Organization, Muguga, KenyaTwo blue wildebeest (Connochaetes taurinus) from the Serengeti National Park in Tanzania and two from Kenya were splenectomised. Of the two from Tanzania, one that had previously had detectable intra-erythrocytic piroplasms of Theileria gorgonis showed an increase in parasitaemia (percentage of erythrocytes infected) to 7%, and the other, which had had no detectable parasites, developed a low-level parasitaemia. The two animals from Kenya had severely exacerbated infections with T. gorgonis and in one case a concomitant infection with Anaplasma marginale. They developed Theileria parasitaemias of more than 70% and died. Attempts to transmit T. gorgonis to steers by means of adults of Rhipicephalus appendiculatus Neum. that had fed as nymphs on infected wildebeest were unsuccessful, although it was shown that the parasite became established in the ticks. Some 500 ticks were used on each steer.Item Attempts to Grow Tissue Culture Cells, Infected with Theileria Parva, in Laboratory Animals(1972) Irvin, A.D.; Brown, C.G.D.; Crawford, J.G.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaTransformed bovine lymphoid cells infected with macroschizonts of Theileria parva were inoculated into normal mice and newborn mice by the subcutaneous route and also into hamster cheek pouches and the anterior chamber of rabbits' eyes. There was no evidence of growth or persistence of parasitized cells in any of the systems, nor were tumour-like masses formed. This contrasts with previous work when inoculation of similar material into whole-body irradiated mice resulted in persistence of parasitized cells and the formation of tumour-like masses.Item Attempts to Grow Tissue Culture Cells, Infected with Theileria parva, in Laboratory Animals(1972) Irvin, A.D.; Brown, C.G.D.; Crawford, J.G.Transformed bovine lymphoid cells injected with macroschizonts of Theileria parva were inoculated into normal mice and newborn mice by the subcutaneous route and also into hamster check pouches and the anterior chamber of rabbits’ eyes. There was no evidence of growth or persistence of parasitized cells in any of the systems, nor were tumour-like masses formed. This contrasts with previous work when inoculation of similar material into whole-body irradiated mice resulted in persistence of parasitized cells and the formation of tumour-like masses.Item Attempts to Infect Swiss Mice with T. Parva-Infected Bovine Tissue Culture(Anthony D I, 1975) Irvin, A.D.The work reported in this thesis was carried out while the author was seconded by the Overseas Development Administration of the United Kingdom (Research Scheme R2845) from his home base, the Agricultural Research Council's Institute .farResearch on Animal Diseases, to the East African Veterinary Research Organisation, Muguga, Kenya. During this time he served as a counterpart member of the UNDP/FAO Tick-borne Diseases Project supported by the United Nations Development Programme with the Food and Agriculture Organisation of the United Nations as the Executing agency in co-operation with the East African Community.Item Autoradiographic Evidence for the Occurrence of Cell Fusion in Cultures of Theileria-Infected Bovine Lymphoid Cells(1974) Irvin, A.D.; Brown, C.G.D.; Boarer, C.D.H.; Crawford, J.G.; Kanhai, G.K.; East African Veterinary Research Organization, Muguga, Kabete, KenyaTheileria parva-infected bovine lymphoid cells, grown in tissue culture, were labelled with tritiated thymidine. Aliquots of this culture were added to equal volumes of unlabelled cultures of T. parva and T. lawrencei. Smears were prepared from the pure and mixed cultures and examined by autoradiography. Virtually all the cells in the pure labelled cultures had taken tip the tritiated thymidine, and in many cells theilerial macroschizonts were also labelled. Some of the multinucleate cells in mixed cultures appeared to be the product of cell fusion since they contained both labelled and unlabelled nuclei.Item Autoradiographic Evidence for the Occurrence of Cell Fusion in Cultures of Theileria-Infected Bovine Lymphoid Cells(1974) Irvin, A.D.; Brown, C.G.D.; Boarer, C.D.H.; Crawford, J.G.; Kanhai, G.K.Theileria parva-infected bovine lymphoid cells, grown in tissue culture, were labelled with tritiated thymidine. Aliquots of this culture were added to equal volumes of unlabelled cultures of T. parva and T. lawrencei. Smears were prepared from the pure and mixed cultures and examined by autoradiography. Virtually all the cells in the pure labelled cultures had taken up the tritiated thymidine, and in many cells theilerial macroschizonts were also labelled. Some of the multinucleate cells in mixed cultures appeared to be the product of cell fusion since they contained both labelled and unlabelled nuclei.Item Blood Parasites of the Impala (Aepyceros Melampus) in the Serengeti National Park(1973) Irvin, A.D.; Omwoyo, P.; Purnell, R.E.; Peirce, M.A.; Schiemann, B.; East African Veterinary Research Organisation, Muguga, P.O. Kabete, Kenya. Serengeti Research Institute, Tanzania National Parks, P.O. Box 3144, Arusha, TanzaniaThe incidence of parasites was: Theileria 44.7%, Trypanozoon 5.8%, Haematoxenus 2.3% and Borrelia 1.2%. There was no evidence that these parasites were pathogenic to their hosts. Rhipicephalus evertsi ticks collected from these animals showed a salivary gland infection rate of 5.4%. Haematoxenus has not been described previously from impala.Item Blood Parasites of the Impala the Serengeti National Park(1973) Irvin, A.D.Blood smears were obtained from 84 impala (Aepyceros melampus) in the Serengeti National Park. The incidence of parasites within these animals was: Theileria 44·7 per cent., Trypanozoon 5·8 per cent., Haematoxenus 2·3 per cent. and Borrelia 1·2 per cent. There was no evidence that these parasites were pathogenic to their hosts. Rhipicephalus evertsi ticks collected from these animals showed a salivary gland infection rate of 5·4 per cent. 'Haematoxenus has not previously been described from impal~.Item Cell Fusion Using Sendai Virus to Effect Interspecies Transfer of Cell Associated Parasite(1974) Irvin, A.D.; Brown, C.G.D.; Kanhai,G. K.; Stagg, D.A.; Rowe, L.W.; Institute for Research on Animal Diseases, Compton, United Kingdom; FAO ; Central Veterinary Laboratory, United Kingdom; Central Veterinary LaboratoryBaby hamster kidney (BHK) cells were fused with Theileria parva-infecled bovine lymphoid cells, using u.v. light-inactivated Sendai virus. The resultant hamster/bovine heterokaryons were shown to be infected with T. parva. In some cases parasites were detected in cells which apparently contained only BHK nuclei.Item Cell Fusion, using Sendai virus, to Effect Inter-Species Transfer of a Cell-Associated Parasite (Theileria Parva).(1974) Stagg, D.A.; Brown, C.G.D.; Rowes, L.W.; Irvin, A.D.; Kanhal, G.K.; UNDP/FAO Tick-borne Diseases Project: East African Veterinary Research OrganizationThe production of interspecific heterokaryons by virus-induced cell fusion was first performed by Harris & Watkins (1965). Since that time the technique has been widely used in a variety of fields but its application in the field of parasitology has not so far been exploited. We have used the technique to effect inter-species, transfer of an intra-cellular host specific parasite (Theileria parva) the causative organism of East Coast fever of cattle.Item Characterisation of Stocks of Theileria Parva by Monoclonal Antibody Profiles(1983) Minami, T.; Spooner, P.R.; Irvin, A.D.; Ocama, J.G.R.; Dobbelaere, D.A.E.; Fujinaga, T.; International Laboratory for Research on Animal Diseases, Nairobi.Sixteen monoclonal antibodies, raised against macro-schizonts of Theileria parva, were tested against 10 different stocks of the parasite. The indirect fluorescent antibody test was used to demonstrate that these antibodies showed different binding affinities to macroschizonts of the various stocks. A profile of antibody binding could thus be prepared for each stock. For a given stock the profile was consistently the same irrespective of culture passage level, host cell background and method of antigen preparation.Item East Coast Fever the Significance of Host Ace in Infection or Immunization of Cattle with Theileria Parva(1979) Irvin, A.D.; Dobbelaere, D.A.E.; Morzaria, S.P.; Spooner, P.R.; Dolan, T.T.; Young, A.S.; Gettinby, G.; International Laboratory for Research on Animal Diseases, Nairobi, Kenya; Kenya Agricultural Research Institute, Muguga, Kenya; University of Strathclyde, Glasgow, UKT a number of tick-borne diseases of cattle, young animals show a significant resistance to infection which is independent of maternally transferred or acquired immunity. Such resistance has been detected in babesiosis (Riek 1968, Zwart and Brocklesby, 1979) an: lasmosis (Ristic, 1968; 1981) and heartwater (Uilenberg, 1983), but,10 evidence for an age-related innate resistance has been described in theileriosis apart from the rather equivocal data reported by Adler and Ellenbogen (1935) for calves infected with Theileria annulata.Item East Coast Fever: 60Co-Irradiation of Theileria Parva in Its Tick Vector, Rhipicephalus Appendiculatus(1974) Purnell, R.E.; Brown, C.G.D.; Burridge, M.J.; Cunningham, M.P.; Emu, H.; Irvin, A.D.; Ledger, M.A.; Njuguna, L.M.; Payne, R.C.; Radley, D.E.; East African Veterinary Research Organization, Muguga P.O. Box 32, Kikuyu, KenyaThree experiments were carried out in which Theileria parva was irradiated in its tick vector, Rhipicephalus appendiculatus. In the first experiment, infected unfed adult ticks were irradiated at doubling doses from 4 to 32 krad. Some of the ticks were then fed for 4, 5, 6, 7 and 8 days on rabbits, and the parasites in their salivary glands examined. Five male and 5 female ticks from each irradiation dose were put onto each of a pair of susceptible cattle, whose reactions were recorded. Increasing doses of irradiation resulted in progressive destruction of the parasites. All cattle receiving ticks irradiated at doses up to and including 16 krad died of East Coast fever (ECF), and one of the cattle receiving ticks irradiated at 32 krad died.Item East Coast Fever: Further Laboratory Investigations on the Use of Rabbits as Vehicles for Infecting Ticks with Theilerial Piroplasms(1974) Purnell, R.E.; Irvin, A.D.; Kimber, C.D.; Omwoyo, P.L.; Payne, R.C.; East African Veterinary Research Organisation, Muguga, KenyaA series of experiments was carried out in which attempts were made to achieve maximum survival of Theileria parva-infected bovine erythrocytes in inoculated rabbits. By varying the treatment of the rabbits and of the erythrocytes and by altering the route of inoculation, it was finally shown that the best and most consistent results could be obtained by the intravenous inoculation of 20 ml of infected bovine blood into splenectomised rabbits. When nymphal Rhipicephalus appendiculatus ticks were fed on such rabbits, the resultant adult ticks showed high Theileria parva infection rates in their salivary glands.Item The Epidemiology of Wildlife Rabies(1970) Irvin, A.D.; Vet, M.B.,; M.R.C.V.S.; M.A.; East African Veterinary Research OrganizationAn historical account of sylvatic rabies is followed by an account of the disease in wildlife at the present time. The disease is largely maintained by members of two orders: Carnivora and Chiroptela. The epidemiological role of rodents and other small mammals may be important, but at present is poorly understood.Item Establishment of Theileria Parva Infected Bovine Tissue Culture in Swiss and Athymic Mice(1977) Irvin, A.D.; Brown, C.G.D.; Stagg, D.A.; East African Veterinary Research Organisation; Institute of Research on Animal Diseases; Central Veterinary LaboratoryTheileria parva-infected bovine lymphoid cells, grown in culture, were inoculated by different routes into neonatal and adult Swiss mice immunosuppressed by irradiation, thymectomy or inoculation of anti-lymphocyte serum. Tumour-like masses, composed of parasitized bovine lymphoid cells, formed at the site of subcutaneous inoculation in immunosuppressed neonatal and adult mice, but consistent establishment of cells following intra-peritoneal inoculation occurred only in neonatal mice. In all cases the degree of cellular establishment was proportional to the degree of immunosuppression. The best “take” was in irradiated neonatally thymectomized mice. Cells underwent short-term multiplication in mice but, as immune competence returned, the cells were rejected. There was no evidence that cells, on passage, became more adapted to grow in mice, nor that mouse cells became parasitized. Culture-derived cells were also inoculated subcutaneously into irradiated and non-irradiated nu/nu, nu/+ and Swiss mice. Tumour-like masses, composed of parasitized bovine lymphoid cells, developed at the site of inoculation in all irradiated mice. In nu/+ and Swiss mice these masses regressed after 2–3 weeks, but in the athymic nu/nu mice there was generally no rejection or cellular degeneration and parasitized cells became widely disseminated in the host's tissues and organs, in some cases causing death. T. parva-infected cells could not be established in non-irradiated nu/nu mice, nor when irradiated nu/nu mice were inoculated by the intra-peritoneal route. “Take” in irradiated neonatal nu/nu mice was also poor. Cells were passaged three times in irradiated nu/nu mice inoculated subcutaneously and it seems probable that indefinite passage of T. parva in mice can now be achieved.Item Establishment of Theileria Parva-Infected Bovine Tissue Culture in Swiss and Athymic (Nude) Mice(1977) Irvin, A.D.; Brown, C.G.D.; Kanhai, G.K.; Stagg, D.A.; East African Veterinary Research Organization, Muguga, P.O. Box 32, Kikuyu KenyaTheileria parva-infected bovine lymphoid cells, grown in culture, were inoculated by different routes into neonatal and adult Swiss mice immunosuppressed by irradiation, thymectomy or inoculation of anti-lymphocyte serum. Tumour-like masses, composed of parasitized bovine lymphoid cells, formed at the site of subcutaneous inoculation in immunosuppressed neonatal and adult mice, but consistent establishment of cells following intra-peritoneal inoculation occurred only in neonatal mice. In all cases the degree of cellular establishment was proportional to the degree of immunosuppression. The best “take” was in irradiated neonatally thymectomized mice. Cells underwent short-term multiplication in mice but, as immune competence returned, the cells were rejected. There was no evidence that cells, on passage, became more adapted to grow in mice, nor that mouse cells became parasitized. Culture-derived cells were also inoculated subcutaneously into irradiated and non-irradiated nu/nu, nu/+ and Swiss mice. Tumour-like masses, composed of parasitized bovine lymphoid cells, developed at the site of inoculation in all irradiated mice. In nu/+ and Swiss mice these masses regressed after 2–3 weeks, but in the athymic nu/nu mice there was generally no rejection or cellular degeneration and parasitized cells became widely disseminated in the host's tissues and organs, in some cases causing death. T. parva-infected cells could not be established in non-irradiated nu/nu mice, nor when irradiated nu/nu mice were inoculated by the intra-peritoneal route. “Take” in irradiated neonatal nu/nu mice was also poor. Cells were passaged three times in irradiated nu/nu mice inoculated subcutaneously and it seems probable that indefinite passage of T. parva in mice can now be achieved.
