Publications

antitheilerial activity of bw720c (buparvaquone): a comparison with parvaquone.	a series of hydroxynaphthoquinones, all derivatives of the antitheilerial hydroxynaphthoquinone parvaquone (993c, clexon; wellcome) was tested for antitheilerial activity against theileria parva (muguga) in vitro. bw720c (buparvaquone) was 20 times more active than parvaquone. when tested in vivo bw720c cured all 13 cattle infected with t parva and all six infected with t annulata treated at a dose rate of 2.5 mg (kg bodyweight)-1 while parvaquone at 20 mg kg-1 cured nine of 10 cattle. all 16 un ...	1985	3929346
bovine alloreactive cytotoxic cells generated in vitro: target specificity in relation to bola phenotype.	cytotoxic cells of bovine origin were generated in primary mlc using stimulator cells of bola w8/w11 phenotype. bovine lymphoblasts transformed by the protozoan parasite theileria parva parva acted as target cells in studies of the specificity of cytotoxicity. when responder cells in mlc did not share w8 or w11 with stimulator cells, cytotoxicity was evident with all targets bearing w8 or w11, or both, and was almost entirely restricted to these products of the bola-a locus. when responder and s ...	1985	2409001
theileria parva: expression of a sporozoite surface coat antigen.	a monoclonal antibody specific for the theileria parva sporozoite, which recognizes a determinant on the surface coat and blocks sporozoite infectivity, was used to investigate the presence of the determinant on other stages of the parasite lifecycle. immunofluorescence techniques did not demonstrate this determinant on the kinete, schizont, merozoite, or piroplasm stages of the parasite. immunoautoradiography, using a tritiated form of the monoclonal antibody, on sections of infected salivary g ...	1985	2410290
immunity in theileriosis.	the theilerioses can be separated on the basis of their principal pathogenic features, into a lymphoproliferative group caused by theileria parva and t. annulata in cattle, and t. hirci in goats and sheep, and a haemoproliferative group caused by t. sergenti and t. mutans both in cattle. in the former group, proliferation of parasites within lymphoid cells followed by lymphodestruction are the main pathogenic features; whereas in the latter group, invasion and destruction of erythrocytes, causin ...	1985	15275582
quantitative studies on theileria parva in the salivary glands of rhipicephalus appendiculatus adults: quantitation and prediction of infection.		1986	2422131
alloreactive bovine t lymphocyte clones: an analysis of function, phenotype, and specificity.	a bovine alloreactive cell population was subjected to complement-dependent lysis with monoclonal antibody (mab) il-a11. the original population and the population depleted of cells bearing the determinant recognized by mab il-a11 were cloned. parent cultures and 21 clones were examined for cytolytic function and for expression of determinants recognized by mab il-a11 and two additional mab, il-a12 and il-a17. clones could be classified according to maximal achievable levels of cytolysis by usin ...	1986	2423592
quantitative studies on theileria parva in the salivary glands of rhipicephalus appendiculatus adults: search for conditions for high infections.		1986	3087897
chemotherapy of east coast fever: the long term weight changes, carrier state and disease manifestations of parvaquone treated cattle.	the weight changes, carrier state and nature of chronic disease in cattle following infection with five isolates of theileria parva and treatment with parvaquone were studied over an 18 month period while the cattle were maintained on normal management under strict tick control. cattle infected with the t.p. parva pugu ii isolate gained weight similarly to uninfected control cattle and did not develop a detectable carrier state or show chronic disease. the cattle in the 4 other isolate groups re ...	1986	3084600
chemotherapy of east coast fever. treatment of infections induced by isolates of theileria parva with halofuginone.	cattle were infected with three isolates of theileria parva and treated with halofuginone lactate during acute clinical disease. the health, weight gain and carrier state of the cattle were monitored for 15 months. limited treatment rapidly reduced fever and parasitosis but parasite recrudescences occurred and 12 out of 21 treated cattle died. persistent carrier states were identified with two t. p. parva isolate infections and a transient carrier state with t. p. lawrencei. three cattle which d ...	1986	2874713
chemotherapy of field cases of east coast fever using halofuginone lactate.	the chemotherapeutic effect of halofuginone lactate (terit, hoechst) was tested against natural pathogenic theileria parva infections (east coast fever, ecf) in 24 cattle. halofuginone lactate, administered per os, 1.2 mg per kg b.wt and repeated after 48 h manifested a potent schizonticidal effect, observed between 5 and 11 days post treatment. disappearance of erythrocytic forms (ef) took long, ranging from 6 to 34 days post treatment. differences on efficacy between halofuginone lactate table ...	1986	2882667
comparative analysis of infection and transformation of lymphocytes from african buffalo and boran cattle with theileria parva subsp. parva and t. parva subsp. lawrencei.	this study compared infection and transformation of peripheral blood mononuclear cells (pbm) of boran cattle and african buffalo in vitro to determine whether differences occurred which could account for the greater susceptibility of boran cattle to infection with theileria parva subsp. parva and t. parva subsp. lawrencei. pbm from buffalo and cattle had a similar percentage of cells which bound t. parva subsp. parva sporozoites (24 to 34%) and in which schizonts developed during the first week ...	1986	3087880
a cell surface antigen associated with theileria parva lawrencei-infected bovine lymphoid cells.	attempts to produce monoclonal antibodies specific for a parasite-encoded or induced antigen on the surface of theileria parva lawrencei-transformed bovine lymphocytes resulted in the identification of the monoclonal antibody j7. this antibody recognizes a membrane glycoprotein on some t.p. lawrencei-infected bovine lymphoid cells but not on any uninfected bovine lymphoid cells. inoculation of allogeneic recipient cattle with t.p. lawrencei-transformed cells bearing the j7 determinant resulted i ...	1986	3703570
effect of chronic trypanosomiasis on immunization against east coast fever.	two experiments were carried out in which uninfected cattle, or cattle chronically infected with trypanosoma congolense, were immunized by the infection and treatment method against east coast fever (ecf; theileria parva infection). chronic trypanosomiasis did not prevent cattle mounting an effective immunological response to ecf immunization and resisting subsequent lethal challenge. there appeared to be no difference in the level or quality of immunity between uninfected cattle and trypanosome ...	1986	3564324
generation of bovine cytotoxic cell lines, specific for cells infected with the protozoan parasite theileria parva and restricted by products of the major histocompatibility complex.	cytotoxic cell lines specific for cells infected with the protozoan parasite theileria parva were generated in vitro by repeated stimulation of peripheral blood mononuclear cells (pbmc) from immune animals with autologous parasitized cells from continuously growing cell lines. in pbmc of 5/7 immune animals tested, maximal levels of killing (80-100%) were obtained at effector to target ratios of 10/1 following 3 to 5 stimulations. no killing of uninfected lymphoblasts was observed. cytotoxic acti ...	1986	3490386
passive endocytosis of sporozoites of theileria parva in macrophages at 1-2 degrees c.	phagocytosis by macrophages is generally considered to involve two steps which can be experimentally dissociated: attachment, which is not energy-dependent, and interiorization, which does not occur below 15 degrees c. we have previously reported entry of the sporozoites of theileria parva into bovine lymphocytes at 2 degrees c by a process of passive endocytosis which appears to depend entirely upon progressive circumferential binding of ligands on the parasite to receptors on the host cell mem ...	1986	3083113
bovine t-cell clones infected with theileria parva produce a factor with il 2-like activity.		1986	3085053
bovine cytotoxic t-cell clones specific for cells infected with the protozoan parasite theileria parva: parasite strain specificity and class i major histocompatibility complex restriction.	we present information on the specificity of three bovine cytotoxic t-cell clones reactive with lymphoblasts infected with the protozoan parasite theileria parva. the clones were derived from peripheral blood mononuclear cells of an animal immunized with t. parva (muguga stock), after five stimulations in vitro with an autologous parasitized cell line. the three clones belonged to the bot8+ subset of t cells, which is similar to the human cd8+ t-cell subset. on the basis of analysis on a panel o ...	1986	3088572
induction of immunity against infection with theileria parva (east coast fever) in cattle using plasma membranes from parasitized lymphoblasts.	protection against challenge with theileria parva was conferred on three of four calves given three or four inocula of plasma membranes prepared from 6 to 12 x 10(8) autologous parasitized lymphoblasts from cultured cell lines. in contrast, calves remained susceptible to infection following immunization with membranes prepared from allogeneic parasitized lymphoblasts. similarly, calves vaccinated with either gamma-irradiated autologous or allogeneic infected cells also died of east coast fever a ...	1986	3085324
maintenance of theileria parva parva infection in an endemic area of kenya.	the maintenance of theileria parva parva infection in an endemic area of kenya on the shore of lake victoria was studied in the field and laboratory. high prevalences of antibodies against t. parva and t. mutans and intra-erythrocytic piroplasms were detected in local zebu (bos indicus) cattle. the mean infection rate of theileria parasites in the tick, rhipicephalus appendiculatus, in field collections was 1.1%. most of the infection was attributed to t. parva parva by application of field tick ...	1986	3092172
intraerythrocytic multiplication of theileria parva in vitro: an ultrastructural study.		1986	3091518
bovine theileriosis in burundi: chemotherapy with halofuginone lactate.	in a field trial 100 cattle suffering from naturally acquired east coast fever caused by theileria parva were treated with halofuginone lactate at a dose of 0.6 to 2.0 mg/kg body weight. records were kept of exact diagnosis, treatment and follow up observations. the total recovery rate was 87%. the rate was highest in local breeds (up to 100%) and lowest in friesian cattle (61.5%). two treatments were administered to nine animals, two of which had relapsed four to six days after the first treatm ...	1986	3765113
a life-cycle stage-specific antigen of theileria parva recognized by anti-macroschizont monoclonal antibodies.	four monoclonal antibodies, raised against macroschizonts of theileria parva, were studied to characterize their antigen binding specificity. the indirect fluorescent antibody test showed that the antigen(s) recognized were present in the macroschizont stage of the parasite life-cycle but not in piroplasm, kinete or sporozoite stages. immunoblot analysis of macroschizont stage antigens suggested that all four antibodies recognized the same antigen. this was a molecule which varied in molecular m ...	1987	3103046
immunization against east coast fever: the use of selected stocks of theileria parva for immunization of cattle exposed to field challenge.	two antigenically different stocks of theileria parva parva (kilifi and marikebuni), previously characterized as belonging to groups a and c respectively on monoclonal antibody (mab) profiles, were selected for immunization of different breeds of cattle against east coast fever (ecf) by the infection and treatment method. a total of 52 immunized cattle and 33 susceptible controls of different group sizes were exposed to field challenge by ticks for periods of 42-90 days at three field sites wher ...	1987	3105160
effect of timing and intensity of challenge following immunization against east coast fever.	when groups of theileria parva parva muguga-immunized cattle were given a homologous lethal challenge at different times after immunization, it was found that 4/6, 5/6, 6/6 and 6/6 animals survived when challenged on days 5, 10, 20 and 30, respectively, post-immunization. with a heterologous challenge (t.p.parva marikebuni), 2/6, 5/6, 4/6, 4/6 and 5/6 cattle survived when challenged on days 5, 10, 20 and 30, respectively, after immunization. all controls, except one, died of east coast fever (ec ...	1987	3125664
a study of bola class ii antigens with bot4+ t lymphocyte clones.	it has hitherto proved difficult to phenotype cattle for class ii histocompatibility antigens using standard serological techniques because of problems of reagent specificity and antigen expression on peripheral blood mononuclear cells (pbms). we recently described the production of class ii-specific alloreactive bovine t cell clones characterized by the bot4+ phenotype. in this report we describe studies of the application of four such clones, derived from a single mixed leucocyte culture (mlc) ...	1987	2955723
monoclonal antibodies that distinguish trypanosoma congolense, t. vivax and t. brucei.	monoclonal antibodies (moabs) were derived against in-vitro-propagated procyclic forms of trypanosoma congolense, t. vivax, t. brucei brucei and t.b. rhodesiense in order to identify antigens for use in immunodiagnosis of african trypanosomiasis. the antibodies have been tested against procyclic and bloodstream form trypanosomes of 13 t. congolense, six t. vivax six t.b. brucei, four t.b. rhodesiense, five t.b. gambiense and three t. simiae isolates from different geographical areas by indirect ...	1987	3306569
alloreactive t cell clones transformed by theileria parva retain cytolytic activity and antigen specificity.	theileria parva is a protozoan parasite which infects and transforms bovine lymphocytes. this study examined the effects of theileria-induced transformation on phenotype and function, in terms of cytolytic potency and specificity, of class i and class ii-specific alloreactive t cell clones. alloreactive t cell clones infected with t. parva (muguga) retained expression of the t cell differentiation antigens bot2, bot4, bot8 and the mature t cell antigen recognized by monoclonal antibody il-a27, a ...	1987	3500864
cytotoxic t-cells elicited in cattle challenged with theileria parva (muguga): evidence for restriction by class i mhc determinants and parasite strain specificity.	the mhc restriction and parasite strain specificity of cytotoxic cells elicited in a group of theileria parva (muguga)-immunized cattle following homologous challenge, were investigated. the cytotoxic cells were specific for parasitized target cells and in 9 of the 10 animals examined, they were clearly genetically restricted. cytotoxicity could be inhibited by monoclonal antibodies (moab) to class i mhc molecules but not by moab to class ii molecules, indicating that a large component of the re ...	1987	3120135
host effector mechanisms against parasites.	the first part of this presentation considers some of the complexities of parasitic infections and parasite-specific effector mechanisms which have hampered the development of practical methods of immunisation against parasitic diseases. in the second part, an outline is given of the effector mechanisms involved in immunity of cattle to the protozoan parasite theileria parva. parasites are antigenically complex organisms which often have distinct developmental stages, sometimes with different pr ...	1987	3307121
field evaluation of parvaquone against naturally occurring east coast fever.	parvaquone (clexon cooper) was clinically tested for efficacy as a treatment for east coast fever (theileria parva parva infection) in naturally infected cattle. the drug showed a suppressive effect on theileria schizonts and piroplasms. a recovery rate of 79% was recorded. best results were obtained when clexon treatment was initiated in the early stage of the disease, before many red blood cells were invaded and before respiratory distress was evident. a carrier state in animals recovered from ...	1987	3105162
experimental induction of theileria parva lawrencei carrier state in an african buffalo (syncerus caffer).	an african buffalo (syncerus caffer), born in captivity and demonstrated to be theileria-free, and 2 susceptible cattle were inoculated with a theileria parva lawrencei sporozoite stabilate. the buffalo had a very mild disease reaction, while the 2 cattle died of acute theileriosis. it was possible to isolate t. p. lawrencei from the buffalo up to 888 days after infection by the application of non-infected rhipicephalus appendiculatus nymphs and up to 657 days after infection by the establishmen ...	1987	3112701
infection of african buffalo (syncerus caffer) and cattle with theileria parva lawrencei after serial passage in cattle.	the infectivity of a theileria parva lawrencei stabilate, from a stock derived from an african buffalo (syncerus caffer) in the serengeti national park, tanzania, was investigated. in the first experiment a buffalo and three cattle were inoculated with a stabilate from a stock passaged three times in cattle. all cattle developed fatal theilerial infections. isolations from the buffalo by tick feeding and cell culture isolation showed that it was infected with t p lawrencei at the time of inocula ...	1987	3112876
isolation of theileria parva lawrencei-infected lymphoid cell lines from free-ranging african buffaloes (syncerus caffer).	lymphoid cells collected from the peripheral blood of 45 free-ranging buffaloes sampled in the masai mara game reserve in kenya were cultured in vitro in an attempt to establish cell lines of intralymphocytic theilerial schizonts. theileria parva lawrencei-infected lymphoblastoid cell lines were established with samples taken from 12 buffaloes, and 11 of these were maintained continuously in vitro. sixteen of the buffalo samples were contaminated with either trypanosomes or viruses. the successf ...	1987	3114847
the pathology of experimental cytauxzoonosis.	clinical, gross post mortem, histological and electron-microscopical data were collected from cats serially killed following experimental infection with cytauxzoon felis. the agent was originally isolated from domestic cats with naturally occurring fatal cytauxzoonosis. morphologically, the blood phase of feline cytauxzoon appeared similar or identical to that described for cases of cytauxzoonosis in african ruminants and closely resembled also the blood phases of theileria spp. and babesia spp. ...	1987	3117851
bovine cytotoxic t cell clones which recognize lymphoblasts infected with two antigenically different stocks of the protozoan parasite theileria parva.	the muguga and marikebuni stocks of theileria parva differ on the basis of cross-protection and in their schizont antigen profile determined with a panel of parasite-specific monoclonal antibodies. the phenotype and specificity of six cytotoxic t cell clones generated from an animal immunized against t. parva (marikebuni) were investigated. all six clones had the bot2+ bot4- bot8+ phenotype, were dependent on both specific antigen and t cell growth factor for proliferation and were restricted by ...	1987	3121356
ultrastructure of the intra-erythrocytic stage of theileria species from cattle and waterbuck.	a transmission electron microscopic study of the intra-erythrocytic stages of a pathogenic theileria parva from cattle and a previously uncharacterized theileria sp. from waterbuck (kobus defassa) in kenya revealed several novel ultrastructural features, associated with feeding and multiplication, in these parasites. in trophozoites a connecting channel was observed between the parasite's cytostome and its intracytoplasmic food vacuole. in some cases the limiting membrane of the food vacuole was ...	1987	3122362
dna probes detect genomic diversity in theileria parva stocks.	different stocks of theileria parva were analysed for restriction fragment length polymorphisms by agarose gel electrophoresis, orthogonal-field-alternation gel electrophoresis (ofage) and southern hybridization with dna probes. polymorphisms seen with dna from purified piroplasms of different t. parva stocks, after digestion with restriction enzymes, were more clearly apparent with ofage than with standard agarose gel electrophoresis. genomic differences between these theilerial parasites were ...	1987	2892129
the bovine autologous theileria mixed leucocyte reaction: influence of monocytes and phenotype of the parasitized stimulator cell on proliferation and parasite specificity.	in the autologous theileria mixed leucocyte reaction (mlr), irradiated theileria parva-infected cells induce proliferative responses in autologous peripheral blood mononuclear leucocytes (pbm), irrespective of the immune status of the donor animal. in this paper we have analysed the cellular basis of this response in naive and immune cattle to determine the theileria specificity of the response. the magnitude of proliferation is dependent on two parameters, namely the presence or absence of mono ...	1987	2950050
development and survival of theileria parva parva in rhipicephalus appendiculatus exposed in the trans-mara, kenya.	nymphal rhipicephalus appendiculatus (trans-mara) were fed on a steer infected with a theileria parva parva (kilae 1) stock isolated from an indigenous steer in the trans-mara division, kenya, which had a high piroplasm parasitaemia. a total of 5000 engorged nymphs which had dropped on one day were enclosed in elongated nylon bolting silk tubes in groups of 200-300 and were transported immediately to the trans-mara where they were suspended vertically in the grass cover with one end touching the ...	1987	3112702
bovine helper t-cell clones specific for lymphocytes infected with theileria parva (muguga).	t-cell clones specific for lymphocytes infected with theileria parva were derived from animals immunized by infection with t. parva (muguga). these clones were non-cytolytic and had the bot4+ bot8- surface phenotype, bot4 and bot8 being the bovine analogues of human cd4 and cd8 molecules. the clones proliferated in response to irradiated autologous lymphoblasts infected with t. parva (muguga) but not to autologous uninfected lymphoblasts or monocytes. they were parasite strain-specific, in that ...	1987	2442694
growth of rinderpest and bovine virus diarrhoea viruses in theileria parva infected lymphoblastoid cell lines.		1988	2844014
corridor disease in south africa: a review of the current status.	the african buffalo (syncerus caffer) is a reservoir host of theileria parva lawrencei the causative organism of corridor or buffalo disease of cattle. this organism can apparently transform its behaviour when tick-passaged through cattle to resemble that of theileria parva parva, causing classic east coast fever (ecf). these are major considerations for the strict quarantine measures imposed on buffaloes from corridor disease endemic areas in south africa. results of continuing studies on diagn ...	1988	3058976
theileria parva: genomic dna studies reveal intra-specific sequence diversity.	theileria parva parva piroplasm dna was purified from 11 different infections of cattle with 6 different east african isolates of the parasite. total dna was also prepared from bovine lymphoblastoid cells infected with schizonts of one of the isolates. two of the infections were with cloned parasites. the dna was of high molecular weight and free from protein and rna, but some of the samples contained a proportion of bovine dna. the 6 samples least contaminated with bovine dna had a mean 'meltin ...	1988	2897626
isolation of theileria parva schizonts from infected lymphoblastoid cells.	this study set out to develop a rapid method for the isolation of schizonts from theileria parva-infected bovine and buffalo lymphoblastoid cells. parasitized lymphoblastoid cells were lysed by treatment with the cytolytic toxins, aerolysin and ah-1 hemolysin, produced by aeromonas hydrophila, and the schizonts were separated by percoll density-gradient centrifugation. light and electron microscopic examination showed that the isolated schizonts from lymphoblastoid cells infected with t. parva ( ...	1988	2903622
bovine t cells, b cells, and null cells are transformed by the protozoan parasite theileria parva.	the target cells for infection and transformation by theileria parva were investigated. peripheral blood mononuclear cells were reacted with monoclonal antibodies specific for bovine leukocyte differentiation antigens, sorted into subpopulations with a fluorescence-activated cell sorter, and infected in vitro with t. parva sporozoites. infected cells were cultured at limiting dilution, and transformed clones were screened with monoclonal antibodies. the results indicated that b cells, t cells (i ...	1988	3123392
chemotherapy of east coast fever: parvaquone treatment of theileria parva parva at intervals after infection.	groups of seven cattle were infected with theileria parva stabilate and treated with parvaquone (20 mg kg-1 bodyweight) zero, four, eight, 12, 14 or 16 days after infection. very early treatments resulted in a rapid recovery or no detectable parasitosis and some cattle were subsequently susceptible to homologous challenge. treatments applied before extensive lymphoid or other organ damage had developed were successful and some cattle treated in advanced disease also recovered. clinical pathologi ...	1988	3375580
immunization of cattle against theileriosis using varying doses of theileria parva lawrencei and t. parva parva sporozoites and oxytetracycline treatments.		1988	3138197
the effect of east coast fever immunisation and different acaricidal treatments on the productivity of beef cattle.	a trial was performed on a farm in the coast province of kenya to study the effects of east coast fever immunisation and different acaricidal treatments on the productivity of immunised and unimmunised beef cattle. eighty cattle were immunised against theileria parva parva (marikebuni) by the infection and treatment method and a similar group was left as an unimmunised control. immunisation had no deleterious effect on the cattle. after immunisation, the immunised and control groups were each su ...	1988	3143177
the effect of temperature on the rate of transmission of theileria parva parva infection to cattle by its tick vector, rhipicephalus appendiculatus.	a steer was infected with theileria parva parva kilae stabilate; nymphal rhipicephalus appendiculatus ticks were applied to its ears so that they completed repletion when the steer had a high piroplasm parasitaemia. the engorged nymphs were subsequently incubated at 28 degrees c for 26-29 days to complete moulting, when the adult ticks were divided into two groups; one was incubated at 18 degrees c for 20 days and the other at 18 degrees c for 14 days and then at 37 degrees c for 6 days. groups ...	1988	3143989
a climate-based model for the development of the ixodid tick, rhipicephalus appendiculatus in east coast fever zones.	east coast fever (theileria parva infection) is an important parasitic disease of cattle in east and central africa. past experimental studies have provided a great deal of information on the dynamics of the life cycle of the tick vector, rhipicephalus appendiculatus. this paper describes a mathematical model based on field observations to explain the close relationship between the tick life cycle and climate. the model provides a basis for the future study of different ecf control programmes us ...	1988	3176300
theileria parva infection induces autocrine growth of bovine lymphocytes.	bovine lymphocytes infected with the parasite theileria parva continuously secrete a growth factor that is essential for their proliferation in vitro and also constitutively express interleukin 2 receptors on their surface. dilution of the secreted growth factor, caused by culturing cells at low density, results in retardation of culture growth. human recombinant interleukin 2, however, effectively substitutes for the diluted growth factor by restoring normal growth rates and also allows theiler ...	1988	3133661
evaluation of cytotoxic lymphocytes and their parasite strain specificity from african buffalo infected with theileria parva.	theileria parva-reactive cytotoxic lymphocytes and their precursors were examined in the blood of african buffalo infected with t. parva and uninfected african buffalo. peripheral blood mononuclear cells (pbm) from eight of 11 infected buffalo were found to have potent cytotoxic activity after stimulation with autologous parasitized cells for 6 days in vitro, while pbm from uninfected buffalo or pbm from infected buffalo not stimulated in vitro had no cytotoxic activity. the cytotoxic activity w ...	1988	3140192
bovine mononuclear cell lines transformed by theileria parva or theileria annulata express different subpopulation markers.	bovine mononuclear cell lines infected with the protozoan parasites theileria annulata and t. parva have been studied with a panel of monoclonal antibodies reacting with bovine lymphocyte subpopulation markers. all infected lines are mhc class ii positive, though the amount of class ii antigen expressed varied between lines, and within individual lines there was variation in the proportion of positive cells from 100% with many, to less than 10%. all lines were negative for a macrophage/monocyte ...	1988	3146047
theileria parva (muguga) infects bovine t-lymphocytes in vivo and induces coexpression of bot4 and bot8.	during the course of a lethal infection with theileria parva (muguga), the surface phenotypes of efferent lymphatic lymphocytes (ell) were analysed to determine whether the parasite preferentially infected any particular subpopulation of cells. in the second week of infection, when the proportion of lymphoblasts and parasitized cells increased to 50% of the total ell, greater than 99% of infected cells expressed t-lymphocyte markers including both bot4 and bot8. from day 10, a population of t-ly ...	1988	3262855
the establishment of infection in the salivary glands of rhipicephalus appendiculatus ticks by transplantation of kinetes of theileria parva and the potential use of the method for parasite cloning.		1988	3130318
immunization of cattle using varying infective doses of theileria parva lawrencei sporozoites derived from an african buffalo (syncerus caffer) and treatment with buparvaquone.	a theileria parva lawrencei isolate in the form of a sporozoite stabilate, derived by feeding clean rhipicephalus appendiculatus nymphal ticks on an african buffalo (syncerus caffer) captured in the laikipia district, kenya, was inoculated into groups of cattle at dilutions between 10(0) and 10(-3). groups of 3 cattle infected with 1 ml inocula at 10(0), 10(-1) and 10(-2) dilutions were treated with 2.5 mg/kg body weight of buparvaquone on day 0 and similar groups were left untreated to act as c ...	1988	3131722
infection of bovine monocyte/macrophage populations with theileria annulata and theileria parva.	infection and transformation of cells of the bovine immune system by theileria annulata and t. parva were compared. preliminary experiments with mammary gland macrophages indicated that they were permissive to infection by t. annulata but only to a limited extent by t. parva. further experiments involved several purified subpopulations of bovine cells including bovine monocytes, t cells and mhc class ii positive and negative populations. these subpopulations were incubated with t. annulata or t. ...	1989	2516673
isolation and characterization of rna from the intracellular parasite theileria parva.	using a rapid procedure to isolate schizonts of the intracellular parasite theileria parva from infected bovine lymphocytes, we have prepared parasite rna that is more than 90% pure. characterization of this schizont rna has revealed the presence of two ribosomal rna species of 3.3 kb and 1.8 kb and a third non-adenylated abundant rna species of 1.9 kb. in vitro translation of the isolated schizont mrna has identified about 200 parasite specific polypeptides, only a few of which could be detecte ...	1989	2469012
expression and characterization of the interleukin 2 receptor in theileria parva-infected bovine lymphocytes.	we have previously shown that interleukin 2 receptors (il2r) are constitutively expressed on the surface of bovine lymphocytes infected with the parasite theileria parva (dobbelaere, d.a.e. et al., proc. natl. acad. sci. usa 1988. 85: 4730). in the present work we characterized these further and showed that il2r (tac antigen) gene expression depended on the continuous presence of the parasite in the host cell cytoplasm. by northern blot analysis we showed that elimination of the parasite, using ...	1989	2786471
theileria parva: bovine helper t cell clones specific for both infected lymphocytes and schizont membrane antigens.	two theileria parva-specific bovine helper t cell clones were used to identify t. parva-derived antigens expressed on the surface of schizont infected lymphoblastoid cells. although the clones proliferated in response to both the immunizing (muguga) and heterologous stocks of t. parva, the patterns of the responses differed, showing that the two clones recognized different antigenic epitopes. both clones were stimulated by autologous infected cells, without an additional source of antigen-presen ...	1989	2529135
differential response of bovine t-cell lines to membrane and soluble antigens of theileria parva schizont-infected cells.	t-cell lines generated from theileria parva-immune cattle were used to identify antigens associated with schizont-infected lymphoblastoid cells. homogenates prepared from t. parva-infected cells were fractionated by differential centrifugation, and antigenically distinct soluble and membrane-bound antigens were detected by the differential stimulation of cell lines derived from two animals. activity in the soluble fraction was not attributable to either a mitogen or interleukin 2. activity in th ...	1989	2533341
pharmacokinetics of halofuginone in cattle.	the pharmacokinetics of the antitheilerial drug halofuginone were evaluated in healthy calves following oral administration, at a dose of 1.2 mg/kg body weight, repeated after 48 h. the maximum plasma concentration after the first dose ranged from 3.8 to 7.7 ng/ml (6.5 ng/ml, mean) and occurred at between 12 and 32 h (22 h, mean). after the second dose, the maximum plasma concentration was 4.8-8.6 ng/ml (7.2 ng/ml, mean) occurring between 12 and 32 h (17 h, mean). the apparent terminal eliminati ...	1989	2590824
the role of the mhc in immunity of cattle to the protozoan parasite theileria parva.		1989	2817738
improved characterization of theileria parva isolates using the polymerase chain reaction and oligonucleotide probes.	theileria parva dna was purified from piroplasms isolated from cattle infected with 5 different east african isolates of the parasite, including the east coast fever reference stock t. p. parva muguga. total cellular dna was prepared from t. parva schizont-infected bovine lymphoblastoid cell cultures (11 isolates). two probes, previously isolated from t. p. parva muguga repetitive genomic dna, were hybridized to restriction digests; closely similar restriction fragment length polymorphism (rflp) ...	1989	2570351
biochemical characterization of activation-associated bovine class i major histocompatibility complex antigens.	utilizing a 'sandwich' elisa assay we have been able to demonstrate that mab w6/32, b1g6 and il-a19 are reactive with three different monomorphic determinants on bovine class i major histocompatibility complex (mhc) molecules. sequential immunoprecipitations performed with the mab revealed that class i molecules on pbm comprise a single population with respect to reactivity with the mab in that the beta 2m-associated proteins bear all three epitopes. by contrast, tcgf-driven lymphoblasts and cel ...	1989	2481992
theileria parva: the immune status of calves born of dams immunised against east coast fever.	eight friesian cross cows three months pregnant to a single friesian bull were immunised against east coast fever by infection with theileria parva (muguga) sporozoite stabilate and treatment with pyrrolidino-methyl tetracycline. they were challenged with the homologous stock four times before calving and a fifth time after calving, and resisted all five challenges which killed all of the five groups of five susceptible controls. calves born to these hyperimmunised dams were fully susceptible on ...	1989	2493670
immunisation of cattle against theileriosis in coast province, kenya: laboratory evaluation of a theileria parva parva stabilate for use in 'infection and treatment' immunisation in the field.	theileria parva parva marikebuni stock, previously shown to give good protection to immunised cattle in kilifi district, coast province of kenya, was chosen for large scale immunisation in the district. a large sporozoite stabilate was prepared and evaluated for efficacy and safety in the 'infection and treatment' method, using a long or short acting formulation of oxytetracycline. susceptible cattle were infected with selected doses of stabilate (10(0), 10(-1), 10(-1.7) and left either as untre ...	1989	2508204
theileria parva: reappearance of schizonts in infected lymphoblastoid cells treated with parvaquone is dependent on interleukin 2-like growth factors.	schizont-infected cell lines derived by in vitro infection of bovine t cell clones with the muguga isolate of theileria parva were treated for 72 hr with the theileriacidal drug, parvaquone, at a concentration of 10 micrograms/ml. this treatment completely eliminated schizonts from the recovered cells, which failed to undergo further proliferation and died. however, treated cells cultured with either bovine t cell growth factor or human recombinant interleukin 2 remained viable, underwent prolif ...	1989	2495228
immunization of cattle with a theileria parva bovis stock from zimbabwe protects against challenge with virulent t.p. parva and t.p. lawrencei stocks from kenya.	following inoculation of 34 bos indicus (boran) cattle with a theileria parva bovis (boleni) stock from zimbabwe, 18 animals underwent mild theilerial reactions, 12 underwent moderate reactions, three suffered severe reactions and one died. when these animals were subsequently challenged with different virulent stocks of either t.p. parva (muguga, marikebuni or mariakani) or t.p. lawrencei (ngong 1 or nanyuki) from kenya, all except two animals resisted challenge. the two reactors were part of t ...	1989	2506688
comparative infection rates of theileria parva lawrencei in salivary glands of rhipicephalus appendiculatus and rhipicephalus zambeziensis.	three cattle, which had been experimentally infected with theileria parva lawrencei and maintained as carriers of the infection, were each infested simultaneously with clean nymphal rhipicephalus appendiculatus and rhipicephalus zambeziensis in ear bags on separate ears. after moulting, the ensuing adult ticks were fed on rabbits for 4 days and their salivary glands were examined for infective stages of the parasite. microscopic examination revealed significantly higher infection rates in the sa ...	1989	2510107
theileria parva in cattle: characterization of infected lymphocytes and the immune responses they provoke.		1989	2497579
theilerial parasites isolated from carrier cattle after immunization with theileria parva by the infection and treatment method.	groups of cattle were immunized with 10(-2) dilutions of sporozoite stabilates of theileria parva lawrencei derived from african buffaloes either alone or in combination with theileria parva parva derived from cattle and concomitant treatment with either long or short-acting formulations of oxytetracyline. at 90 or 120 days after infection, uninfected rhipicephalus appendiculatus nymphal ticks were applied to individual immunized cattle and the resultant adults ticks were applied to individual s ...	1989	2508037
infection with the intracellular protozoan parasite theileria parva induces constitutively high levels of nf-kappa b in bovine t lymphocytes.	the intracellular protozoan parasite theileria parva causes a lymphoproliferative disease of t cells in cattle and uncontrolled lymphocyte proliferation in culture. we have identified and characterized in infected cells the transcriptional activator, nf-kappa b, whose recognition motifs have been identified in several gene enhancers important for lymphocyte-specific gene expression. nf-kappa b is normally constitutively activated in nuclear extracts derived from b cells and can be induced in t c ...	1989	2513476
protein changes in bovine lymphoblastoid cells induced by infection with the intracellular parasite theileria parva.	protein and glycoprotein changes induced in bovine lymphoblasts by infection with theileria parva were analyzed by high-resolution two-dimensional gel electrophoresis. uninfected and infected cloned bovine t and b lymphoblasts were biosynthetically labeled with [35s]methionine and their two-dimensional autoradiographic patterns were compared with each other and with the pattern obtained using purified labeled schizonts. ten proteins were found in infected cells which were not present in uninfect ...	1989	2514355
molecular aspects of theileria parva and approaches to vaccine development for animals.		1989	2516996
infection of bovine t cell clones with genotypically distinct theileria parva parasites and analysis of their cell surface phenotype.	different stocks and stabilates within a stock of theileria parva were analysed for genotypic differences and for their effect on the expression of host cell surface antigens following infection of bot8+ t lymphocyte clones. the parasites were characterized in vitro by hybridization of t. parva-specific dna probes to southern blots of endonuclease-digested dna from the infected t cell clones. phenotypic changes in the host lymphoblastoid cells before and after infection were examined using linea ...	1989	2574438
theileria parva: an intracellular protozoan parasite that induces reversible lymphocyte transformation.		1989	2502427
transmission of theileria parva bovis (boleni strain) to cattle resistant to the brown ear tick rhipicephalus appendiculatus (neumann).	four crossbred bos taurus oxen resistant to rhipicephalus appendiculatus and three tick naive oxen of the same breed, which were all infested with adult r. appendiculatus infected with the boleni strain of theileria parva bovis, acquired theileria infection. all four tick resistant oxen recovered after a mild febrile reaction. two of the tick naive oxen died while the third recovered after a protracted period. it is suggested that tick resistance in cattle may be an important factor in establish ...	1989	2665253
phenotypic characterization of theileria parva schizonts by two-dimensional gel electrophoresis.	biosynthetically radiolabelled theileria parva schizonts were purified from bovine lymphoblastoid cells and their proteins were analyzed by two-dimensional gel electrophoresis and autoradiography. the protein spot patterns of schizont proteins from three stocks of t. parva parva indicated that the phenotypic diversity among the stocks was minimal, with the mariakani and uganda stocks being identical and the muguga stock showing only a few differences in minor spots. comparison of the spot patter ...	1989	2516314
cytotoxic t cells in immunity to theileria parva in cattle.		1990	2137767
oxytetracycline inhibition of mitochondrial protein synthesis in bovine lymphocytes infected with theileria parva or stimulated by mitogen.	oxytetracycline (otc) significantly inhibited cytochrome c oxidase activity in bovine lymphocytes infected with theileria parva and in uninfected mitogen-stimulated lymphocytes. the inhibitory effect was detected in vitro within 24 h of treatment with drug concentrations as low as 1 micrograms/ml. following mitogen stimulation of lymphocytes, concentrations of 3 and 10 micrograms/ml otc completely inhibited an increase in cytochrome c oxidase activity for 48-72 h. this inhibitory activity was co ...	1990	1965455
strain specificity of bovine theileria parva-specific cytotoxic t cells is determined by the phenotype of the restricting class i mhc.	to determine whether the major histocompatibility complex (mhc) phenotype of cattle could affect the parasite strain specificity of immunity to theileria parva by influencing the antigenic specificity of theileria-specific cytotoxic t lymphocytes (ctl), we investigated the parasite strain specificity of theileria-specific ctl clones derived from cattle of different class i mhc phenotypes. thirty-one class i-restricted ctl clones were generated from four cattle immunized with the muguga stock of ...	1990	1968884
sfii and noti polymorphisms in theileria stocks detected by pulsed field gel electrophoresis.	dnas of theileria parva parva, t. p. lawrencei, t. p. bovis and theileria mutans stocks, from kenya, uganda, zanzibar and zimbabwe were digested with either sfii or noti and analysed using contour-clamped homogeneous electric field (chef) and field-inversion gel electrophoresis (fige). the sfii-digested t. parva genomic dna resolved into approximately 30 fragments while the noti digestion produced between 4-7 bands. the summation of the sizes of sfii fragments gave an estimate of 9-10 x 10(6) ba ...	1990	1972977
expression of tac antigen component of bovine interleukin-2 receptor in different leukocyte populations infected with theileria parva or theileria annulata.	the tac antigen component of the bovine interleukin-2 receptor was expressed as a cro-beta-galactosidase fusion protein in escherichia coli and used to raise antibodies in rabbits. these antibodies were used for flow cytofluorimetric analysis to investigate the expression of tac antigen in a variety of theileria parva-infected cell lines and also in three theileria annulata-infected cell lines. cells expressing tac antigen on their surface were found in all t. parva-infected cell lines tested wh ...	1990	1979317
il-2 can enhance the cyclosporin a-mediated inhibition of theileria parva-infected t cell proliferation.	the effect of cyclosporin a on the continuous proliferation of theileria parva-infected t cells was tested and compared with its effect on the con a-induced proliferation of bovine lymph node cells. the effect of ril-2 on cyclosporin a-treated cells was also tested. whereas the con a-induced proliferation of bovine lymph node cells was completely inhibited by cyclosporin a, the continuous growth of t. parva-infected cells was only partly inhibited. in both cases the inhibition was accompanied by ...	1990	2104902
a single exon codes for the enzyme domain of a protozoan cysteine protease.	theileria parva is an intracellular protozoan parasite of cattle. we have determined the nucleotide sequence of a gene and cdna coding for a cysteine protease of t. parva. the gene is divided into two exons. the first exon codes for a signal sequence and for part of the "pro" region of the zymogen. the second exon codes for the remainder of the pro region, including residues thought to be involved in zymogen processing, and for the entire enzyme domain. part of this exon cross-hybridizes, at hig ...	1990	2120221
immunization of cattle against theileria parva bovis and their exposure to natural challenge.	theileria parva bovis isolates were tested for their immunizing capacity under natural field challenge on willsbridge farm in the highveld of zimbabwe. fifteen susceptible sussex yearlings were immunized with the boleni stock and 15 with a mixture of three isolates from the farm, using tick-derived sporozoite stabilates. no chemoprophylaxis was used. a dose of 0.1 ml of stabilate appeared to be safe in preliminary laboratory experiments, but the reactions were severe in the sussex cattle and one ...	1990	2125158
characterisation of the gene encoding a 104-kilodalton microneme-rhoptry protein of theileria parva.	a neutralizing antiserum, c16, raised against sporozoites of theileria parva parva was used to screen a lambda gt11 expression library of t. parva parva (muguga) genomic dna fragments. proteins encoded by one phage clone, lambda tps-17, were reactive with the c16 antiserum. detailed characterisation of the dna insert showed it to encode determinants found on four theilerial antigens of approximately 104, 90, 85 and 35 kda. the sequence encoded by the clone is expressed during sporogony as a sing ...	1990	1689460
the effects of oxytetracycline on theileria parva in vitro.	when bovine peripheral blood leucocytes were infected with theileria parva sporozoites, immediate treatment with oxytetracycline (otc) inhibited the development of sporozoites to mature schizonts. the extent of inhibition was dependent on drug concentration and duration of treatment. concentrations of 5 micrograms/ml otc, or higher, for 8 days completely inhibited the establishment of schizonts and their ability to transform host cells. a cytostatic effect on schizont-infected cell lines was fou ...	1990	2107502
low-dose oral administration of human interferon alpha can control the development of theileria parva infection in cattle.	two natural human interferon alpha preparations, (nhuifn-alpha [cantell]) and (nhuifn-alpha [isi]), were used for the oral treatment of cattle experimentally infected with theileria parva parva. in the first experiment, 8 friesian bulls were inoculated with a 1 in 10 dilution of a sporozoite stabilate of t.p. parva (marikebuni) stock. four of the cattle were treated daily with 1 international unit/kg body weight (i.u./kg bwt) of nhuifn-alpha (cantell) from day -2 to day 8 p.i. none of the 4 calv ...	1990	2124670
theileria parva: the nature of the immune response and its significance for immunoprophylaxis.	theileria parva is a tick-borne haemoprotozoan parasite of cattle and buffalo which is responsible for considerable economic losses to cattle farming in eastern, central and southern africa. infection with the parasite results in an acute lymphoproliferative disorder with high mortality, but animals which survive infection are solidly immune to homologous challenge. such immunity can be reproduced by infecting cattle with the parasite and treating them with tetracyclines or theilericidal drugs, ...	1990	2132688
recognition of soluble theileria parva antigen by bovine helper t cell clones: characterization and partial purification of the antigen.	theileria parva-specific bovine bot4+ th cell clones were used to characterize ag associated with t. parva schizont-infected lymphoblastoid cells. all of the clones tested responded to cells infected with the immunizing (muguga) as well as heterologous stocks of t. parva, indicating that the t cells are specific for an ag shared by several geographically diverse parasites. the response was apparently mhc-restricted, and induced by ag expressed on the infected cell surface. in the presence of aut ...	1990	2136883
characterization of a bovine leucocyte differentiation antigen of 145,000 mw restricted to b lymphocytes.	a new bovine b-cell differentiation antigen is described that is detected by three monoclonal antibodies (mab). the antigen is not an immunoglobulin and is precipitated from peripheral b cells as a molecule with an approximate molecular weight (mw) of 120,000 or 145,000 before and after reduction, respectively. data obtained from two-colour cytofluorimetry and immunohistochemistry confirmed that the antigen was found only on mature b cells and on cells with dendritic morphology in the follicles ...	1990	2185984
age resistance to theileria parva bovis infection in calves.	data collected in the zimbabwean province of mashonaland-west, in the period 1980-1988, showed that mortality in calves owing to theileria parva bovis infection (january disease) was significantly lower in animals younger than 7 months than in older cattle. groups of seven holstein-friesian calves from non-immune dams aged approximately 1, 4, 7, 10 and 13 months were infected with a theileria parva bovis tick-derived stabilate. the dose chosen was lethal for 40% of the calves in the trial. morta ...	1990	2267723
geographical information systems for studying the epidemiology of cattle diseases caused by theileria parva.	data on selected variables which influence the epidemiology of cattle diseases caused by theileria parva were assembled and entered in a computerised geographical information system. variables studied included the distributions of major hosts (cattle and buffalo), the vector ticks (rhipicephalus appendiculatus and related species) and the reported presence of east coast fever, corridor disease and january disease. in addition, the distribution of climatic suitability for r appendiculatus was ass ...	1990	2327044
evaluation of infection and treatment methods in immunization of improved cattle against theileriosis in an endemic area of kenya.	five experiments were carried out to determine the efficacy of immunization against theileriosis in an endemic area of kenya using artificial infection with a mixture of stabilates of theileria parva stock or natural infection and treatment with parvaquone or several formulations of oxytetracyclines. for the first four experiments, introduced, susceptible sahiwal/friesian crosses were used and in the fifth, calves of boran/maasai zebu crosses born on the site. cattle were infected either artific ...	1990	2343540
a bovine class i major histocompatibility complex molecule plus a theileria parva antigen resembles mouse h-2kd.	two bot2+, bot8+ cytotoxic t cell clones were generated from peripheral blood of a steer immunized with the intracellular protozoan parasite theileria parva. both cytotoxic t cell clones appeared to be restricted by the same major histocompatibility complex (mhc) molecule and were specific for the immunizing parasite clone. however, one of the two clones also recognized uninfected mouse cell lines carrying the h-2d haplotype. inhibition of cytotoxicity with monoclonal antibodies specific for pol ...	1990	2125183
development of recombinant antigen vaccines for the control of theileriosis.	immunization against theileria parva involves infection with sporozoites and simultaneous treatment with a long-acting tetracycline. for t. annulata, immunization is achieved by inoculation of attenuated schizont-infected lymphocytes. the two methods are inadequate because of the use of live organisms and the methods are also bedevilled by the multiplicity of strains, particularly of t. parva. for these reasons, alternative methods of control are being sought. in this review an attempt is made t ...	1990	2149448
identification of lambda gt11 clones encoding the major antigenic determinants expressed by theileria parva sporozoites.	an antiserum, c16, was raised in cattle against freeze-thawed extracts of sporozoites of theileria parva (muguga). this antiserum, which neutralizes sporozoite infectivity in vitro, identified theileria-specific antigens having approximate molecular masses of 105, 90, 85, 69, 67, 52, 47, and 43 kilodaltons (kda) on western blots (immunoblots) of infected tick salivary gland extracts. the antiserum was used to screen an expression library of t. parva (muguga) genomic dna fragments. three recombin ...	1990	1692810
immunization with theileria parva parasites from buffaloes results in generation of cytotoxic t cells which recognize antigens common among cells infected with stocks of t. parva parva, t. parva bovis, and t. parva lawrencei.	immunity to infection by the protozoan parasite theileria parva in cattle is partially attributable to cytotoxic t cells, which kill lymphocytes infected with the schizont stage of the parasite. here we evaluated five stocks of buffalo-derived t. parva lawrencei parasites and two stocks of cattle-derived t. parva parva parasites for their ability to induce in vivo cytotoxic t cells which can kill lymphocytes infected with a wide variety of strains of t. parva parasites. a group of seven full-sib ...	1990	1699896