Browsing by Author "Kanhai, G.K."
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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 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 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.Item Growth of Theileria Parva-Infected Bovine Lymphoid Cells in Whole-Body Irradiated Mice(1974) Irvin, A.D.; Brown, C.G.D.; Kanhai, G.K.; Wanguru, S.; Cooper, J.E.; East African Veterinary Research Organisation, Kikuyu, Kenya. Kenyatta National Hospital, Nairobi. Veterinary Services Division, PO Kabete, Kenya.Bovine lymphoid cells grown in tissue culture and infected with Theileria parva were inoculated subcutaneously into groups of seven strains of mice which had been subjected to whole-body irradiation of 710 Roentgen. Tumour-like masses containing parasitised bovine cells developed in all strains of mice, but growth was most successful in the 'A2G' strain.Item The incidence of Theilerial Parasites in East African Buffalo (Syncerus caffer).(1978) Young, A.S.; Brown, C.G.; Burridge, M.J.; Grootenhuis, J.G.; Kanhai, G.K.; Purnell, R.E.; Stagg, D.A.; Immunological Research on Tick-borne Cattle Diseases and Tick Control Project; East African Veterinary Research Organisation, Muguga245 buffalo from 13 areas of East Africa were examined for theilerial infections. The vast majority of buffalo (97.1%) examined had piroplasms in their erythrocytes. Theileria lawrencei was isolated from the buffalo by tick feeding and cell culture and was found to be common in most of these buffalo populations. Also over 50% of the buffalo had indirect fluorescent antibody (IFA) titres to T. lawrencei. T. mutans was only isolated from 3 buffalo populations but is probably common. Haematoxenus sp. was detected in the blood of 56% of the buffalo sampled. In the light of these results the role of buffalo as a reservoir of cattle pathogenic theilerioses in East Africa is discussed.Item Infection and Transformation of Bovine Lymphoid Cells In Vitro by Infective Particles of Theileria Parva(1973) Brown, C.G.D.; Stagg, D.A.; Purnell, R.E.; Kanhai, G.K.; Payne, R.C.; East African Veterinary Research Organization Muguga, PO Box 32, KikuyuTechniques recently developed in this laboratory can be used to infect cattle reproducibly with East Coast fever with infective particles of Theileria parva collected from the tick vector, Rhipicephalus appendiculatus. Infective particles can be collected either as in vitro tick feed material by inducing prefed, infected ticks to salivate into capillary tubes containing foetal calf serum1, or as ground tick supernatant obtained by grinding the ticks in Eagle's minimum essential medium with Earle's salts (MEM) supplemented with bovine plasma albumin (Fraction V from bovine plasma) (BPA) and collecting the supernatant2.Item Isolation of a Theileria Species from Eland (Taurotragus Oryx) Infective for Cattle(1977) Young, A.S.; Grootenhuis, J.G.; Kimber, C.D.; Kanhai, G.K.; East African Veterinary Research Organisation, Muguga, Kikuyu, KenyaTheileria infections were induced in cattle by feeding ticks on them from 3 sources:(a) adult rhipicephalid ticks obtained from the vegetation in a paddock containing an eland EAO at the Animal Orphanage, Nairobi National Park, Kenya, (b) Rhipicephalus appendiculatus adults fed as nymphs on the same eland, (c) R. pulchellus adults fed as nymphs on an eland W 68 captured in the Machakos district of Kenya. Both eland were harbouring Theileria parasites at the time nymphal ticks were fed. Mild infections were produced when adult ticks from these 3 batches were applied to cattle associated with low numbers of schizonts and piroplasms. The indirect fluorescent antibody test demonstrated that cattle recovered from infections resulting from the above 3 tick batches from eland W 68 and EAO produced antibodies which reacted with schizont antigen of the Theileria species (eland) and Theileria species (Githunguri) which had been isolated from cattle and not to antigens of other Theileria species used. The cattle recovered from the Theileria species (eland) were fully susceptible to a lethal challenge of a T. parva (Muguga) stabilate. It was concluded that the Theileria species (eland) and Theileria species (Githunguri) may be closely related and could represent a new species of Theileria infective to cattle.Item Phagocytosis of Trypanosoma (Nannomonas) congolense by circulating macrophages in the African buffalo (Syncerus caffer)(1975) Young, A.S.; Kanhai, G.K.; Stagg, D.A.; Immunological Research on Tick-home Cattle Diseases and T ck Control Project‡, East African Veterinary Research Organisation, Muguga, PO Box 32, Kikuyu, KenyaNineteen African buffalo were short in the Mara region of Kenya. Leucocytes were separated from the buffalo samples by sedimentation and centrifugation. In leucocyte smears of six buffalo, trypanosomes were detected and in two of them, high levels of phagocytosis of Trypanosoma (Nannomonas) congolense by circulating macrophages were demonstrated.Item Response of Whole-body Irradiated Mice to Inoculation of Theileria Parva Infected Bovine Lymphoid Cells(1974) Irvin, A.D.; Brown, C.G.D.; Kanhai, G.K.; Kimber, C.D.; Crawford, J.G.; East African Veterinary Research Organization, Muguga, P.O. Kabete, KenyaTheileria parva-infected bovine lymphoid cells produced tumour-like masses at the site of subcutaneous inoculation in whole-body irradiated Swiss mice. The optimal dose range for irradiation was 800 to 900 rad. Intact parasitized cells were detected in these masses up to about d. 17 after inoculation and were then gradually rejected as the host's defence mechanisms recovered. The masses appeared to be produced by the continued growth of tissue culture in the immuno-suppressed host. There was no evidence that mouse cells became parasitized.Item Studies on Cell Fusion Between Babesia Rodhaini-Infected Mouse Erythrocytes and Baby Hamster Kidney Cells(1975) Irvin, A.D.; Stagg, D.A.; Kanhai, G.K.; Brown, C.G.D.; Omwoyo, P.L.; East African Veterinary Research Organization, Muguga, P.O. Box 32, Kikuyu, KenyaHeterokaryons were formed by fusion of B. rodhaini-infected mouse erythrocytes and baby hamster kidney (BHK) cells, using Sendai virus. The erythrocyte membrane rapidly lysed inside the BHK cell cytoplasm releasing free parasites. There was no evidence that parasite multiplication occurred inside the BHK cells, nor that parasitized BHK cells were infective for mice. Transient erythrocyte homokaryons were observed in some preparations. The approach indicates a possible method for the in vitro cultivation of Babesia.Item Theileria Lawrencei Infection of Cattle and African Buffalo: Evaluation of a Buffalo Cell Culture Schizont Antigen for the Indirect Fluorescent Antibody Test.(1974) Burridge, M.J.; Young, A.S.; Stagg, D.A.; Kanhai, G.K.; Kimber, C.D.; East African Veterinary Research Organization, Muguga, PO Box 32, Kikuyu, KenyaA schizont antigen for the indirect fluorescent antibody test was prepared from culture suspension of African buffalo lymphoid cells infected with Theileria lawrencei (T.l.) macroschizonts. This antigen was compared with Theileria parva and T.l. cell culture schizont antigens prepared from infected bovine cells, using bovine antiserum to parva and T.l. and buffalo antiserum to T.l. Complete cross-identity of these three antigens was found with all antiserum. Five buffalo naturally infected with T.l. had significant antibody titres to all three schizont antigens, using an anti-bovine conjugate in the indirect fluorescent antibody test. The peak antibody titres of these buffalo were between 1:40 and 1:2560 to the three schizont antigens. These results suggest that this test could be usefully employed in epidemological surveys.Item Transplantation of bovine lymphosarcoma cells to athymic (nude) mice(1977) Irvin, A.D.; Brown, C. G. D.; Kanhai, G.K.; Stagg, D. A.; UNDP/FAO Tick-borne Diseases Project, East African Veterinary Research OrganizationBovine lymphosarcoma cells, previously established in culture, were inoculated subcutaneously into groups of irradiated and non-irradiated athymic (nude) mice. Tumours developed at the site of inoculation in all of the irradiated mice but in none of the others. Tumour growth was progressive in all cases but there was no evidence of invasion of surrounding tissues nor of metastasis. Tumour cells were passaged directly to further mice and a similar growth pattern was recorded. The use of this system suggests a possible small animal laboratory model for bovine lymphosarcoma
