Publications

letter: effect of dexamethasone upon trypanosoma congolense infection in calves.		1975	1166500
[course of trypanosoma musculi infections in nmri mice (author's transl)].	the trypanosomes multiply during prepatency after minimal infection by a factor of 2.2-3.6 per day. during patency, increase of trypanosome number in the peripheral blood is basically non-logarithmic as the actual proliferating forms remain hidden in special vascular areas (kidney, placenta). the mean increase during patency is approximately linear, typically by 1-10 trypanosomes per 10(4) erythrocytes per day, and depends on the number of infective organisms introduced. - length of parasitemia ...	1975	1236679
comparative studies on the laboratory diagnosis of experimental trypanosoma congolense infection in sheep.	comparative studies on the laboratory diagnosis of sheep experimentally infected with t. congolense were carried out by parasitological and serological methods during a period of 53 weeks. trypanosomes were most numerous in the first weeks after inoculation, when they were detectable by all three parasitological tests: the wet mount preparation, the haematocrit centrifuge technique, and the mouse inoculation test. in the later stages of the infection, trypanosomes were observed intermittently by ...	1976	773317
studies on the anemia in experimental african trypanosomiasis. ii. the pathogenesis of the anemia in calves infected with trypanosoma congolense.	it was postulated that the anemia commonly seen in mammalian trypanosomiasis, and specifically in trypanosoma congolense-infected calves, was of immunological origin. specifically, we postulated that trypanosome antigen-antibody-complement complexes, deposited on the surface of erythrocytes of infected calves, resulted in their immune elimination leading to clinical anemia. this hypothesis was tested experimentally. immunoglobulins bound to the erythrocytes of 13 infected calves were detected by ...	1976	937631
the immune response of zebu cattle infection with trypanosoma congolense and t. vivax.	zebu cattle were infected with trypanosoma congolense and t. vivax and changes in the levels of serum immunoglobulins were measured during infection and after treatment. increases in the levels of igm occurred within 14 days of infection coincidentally with the first appearance of trypanosomes in the peripheral blood. igm levels rose to 2-10 times preinfection levels and remained high until the animals were treated with diminazene aceturate. levels then declined to approximately pre-infection le ...	1976	938121
letter: circadian rhythms in trypanosoma congolense.		1976	960209
[adherence phenomena in trypanosoma congolense (author's transl)].	two adherence phenomena in trypanosoma congolense as a possible cause of trypanosome aggregation in the capillaries of certain organs are described: 1. adherence of trypanosomes to blood cells of nonimmune mice, 2. dovetailing of trypanosome membranes into one another and into the vessel wall.	1976	982553
lymphocyte function in experimental african trypanosomiasis: mitogenic effects of trypanosome extracts in vitro.	extracts of trypanosoma brucei and trypanosoma congolense were incubated in vitro with nonimmune lymphocytes of mice, rats, guinea pigs, and rabbits in order to test for mitogenic effects or for other characteristics of polyclonal b lymphocyte activators. trypanosome extracts (te) were not mitogenic for spleen cells of mice, rats, and guinea pigs in vitro, nor did the parasite extracts alter the mitogenic responses of lymphocytes from these animals to known b- and t-cell mitogens. te also failed ...	1976	992878
the response to trypanosoma congolense infection in calves. determination of immunoglobulins igg1, igg2, igm and c3 levels and the complement fixing antibody titres during the course of infection.	serum immunoglobulins, igg1, igg2, igm and c3 levels and the complement fixing antibody titres were determined over a period of 15 to 18 weeks in 13 calves infected with trypanosoma congolense. the mean igm concentration increased from 2.88 mg/ml prior to infection to 23.75 mg/ml at the 3rd week after infection. this level dropped by the 5th week but elevated values of 13-19 mg/ml were maintained until the end of the experiment. the mean igg1 level increased from 10.55 mg/ml to a peak of 26.90 m ...	1976	1006799
the generation of toxic activity from trypanosoma congolense.	trypanosoma congolense organism, on incubation at 20 degrees c for 91/2h, were found to generate phospholipase like activity which was capable of mediating lysis of both nucleated cells and erythrocytes as well as acute inflammatory response on intradermal inoculation.	1976	1021440
animal trypanosomiasis in zambia: incidence in cattle in southern province.		1976	16300132
the release of soluble vasoactive material from trypanosoma congolense in intraperitoneal diffusion chambers.	millipore diffusion chambers containing living or lysed trypanosoma congolense cause a local inflammatory reaction when implanted intraperitoneally into rats. empty chambers do not do this. the active material is of low molecular weight and is possibly peptide in nature. it appears to act by increasing local vascular permeability. it was found to be neither chemotactic nor cytotoxic in several assay systems. it is considered that this material may contribute to the pathogenesis of t. congolense ...	1977	860314
the generation and identification of the hemolysin of trypanosoma congolense.	the hemolytic activity of trypanosoma congolense appears to be due to the presence of free fatty acids generated by the action of phospholipase a on endogenous phosphatidyl choline. some lysolecithin also contributes to the lytic activity. trypanosoma lewisi, being devoid of phospholipase a, does not generate free fatty acids and is therefore non-hemolytic.	1977	891767
trypanosomiasis:goats as a possible reservoir of trypanosoma congolense in the republic of the sudan.	experimental trypanosoma congolense infections of goats and calves were compared. goats developed a chronic form of trypanosomiasis, often recovering spontaneously from a strain which caused an acute fatal disease in calves. goats may be important in the maintenace of t. congolense in nature in the sudan.	1977	910302
trypanosoma congolense: partial cyclic development in a glossina cell system and oxygen consumption.		1977	915617
a comparative study of the responses of the thymus, spleen, lymph nodes and bone marrow of the albino rat to infection with trypanosoma congolense and trypanosoma brucei.	using 90 albino rats, a comparison was made between the response to experimental infections of trypanosoma brucei and t congolense of approximately three weeks duration by observation of parasitaemia, packed cell volume values, post mortem spleen and lymph weights, and histology of thymus, spleen, lymph nodes and bone marrow. in t congolense infection, phagocytosis of trypanosomes in the spleen appeared to be the main response of the host's haemopoietic tissues to the parasites, which were obser ...	1977	928984
anaemia in trypanosomiasis: mechanisms of erythrocyte destruction in mice infected with trypanosoma congolense or t. brucei.	studies in mice infected with t. brucei or t. congolense showed that increased red cell destruction in the spleen occurred as from the third day of patent parasitaemia and this resulted in a marked reduction of the half-life of transfused syngeneic 51cr labelled cells. there was a progressive increase in the osmotic fragility of the red cells, especially in t. congolense infected mice which also showed a more severe anaemia. the antiglobulin test was only rarely positive in the late stages of t. ...	1977	16466
studies on antigenic variation of cyclically transmitted trypanosoma congolense.	antigenic variants of t. congolense transmitted by g. m. morsitans through normal and x-irradiated mice were investigated by means of the neutralization test and ifat. clones of a cyclically passaged derivative strain were isolated from irradiated and normal mice. the ifat revealed cross immunofluorescent reactions between most of the stabilates, whereas only the two clones obtained from irradiated mice were totally neutralized by their homologous antisera. these two antisera showed no cross neu ...	1977	67787
fluorescent antibody analysis of host plasma components on bloodstream forms or african pathogenic trypanosomes. i. host specificity and time of accretion in trypanosoma congolense.		1977	328843
the aetiology and significance of the phagocytosis of erythrocytes and leucocytes in sheep infected with trypanosoma congolense (broden, 1904).	the phagocytosis of erythrocytes and leucocytes in sheep infected with trypanosoma congolense is shown to be due to the coating of the blood cells with trypanosomal antigen. the occurrence of the phagocytic activity is dependent on fluctuations of the parasitaemia and is significant in maintaining the anaemic state of the subject.	1978	343212
the generation of phospholipase a and hemolytic fatty acids by autolysing suspensions of trypanosoma congolense.	when t. congolense undergoes autolysis there is a concomitant appearance of phospholipase a activity and hemolytic fatty acids. the generation of enzyme activity is exponential, and the appearance of hemolytic activity corresponds to a free fatty acid concentration of 0.02 to 0.03 mg. per ml. the concentration of the trypanosome suspension markedly affected the kinetics of the generation process. in contrast, the autolysis of t. lewisi did not generate hemolytic activity unless exogenous phospho ...	1978	347651
circadian rhythms of trypanosoma congolense in laboratory rodents.		1978	366815
immunosuppressive effect of trypanosoma congolense and trypanosoma vivax on the secondary immune response of cattle to mycoplasma mycoides subsp mycoides.	trypanosoma congolense and t vivax infections in cattle were shown to have a suppressive effect on the secondary humoral immune response to m mycoides. the trypanosome infections caused an involution of the thymus. the secondary response was biphasic in nature and was unrelated to infection with trypanosomes.	1978	373035
mitogenicity of autolysates of trypanosoma congolense.	autolysates of trypanosoma congolense, in subcytotoxic amounts, were found to be highly mitogenic in vitro for the spleen cells of normal mice. significant amounts of [3h]-thymidine were also incorporated by the responding spleen cells of nu/nu (athymic) mice. in contrast, the spleen cells of cyclophosphamide-treated mice were unresponsive. the findings suggest that a potent b-cell-mitogen is generated by the autolysing t. congolense organism.	1978	620724
characterisation of the surface coat of trypanosoma congolense.		1978	625332
an extravascular site of development of trypanosoma congolense.		1978	643055
mechanisms of the anemia in trypanosomiasis: studies on the role of the hemolytic fatty acids derived from trypanosoma congolense.	trypanosoma congolense releases a number of hemolytic free fatty acids on autolysis of which the most potent is linoleic acid. these fatty acids can lyse washed rat and bovine erythrocytes in vitro. autolysed t. congoleuse will cause increased fragility of erythrocytes in whole rat blood but not in whole bovine blood. the lack of effect of these fatty acids on bovine erythrocytes tends to be confirmed by the failure of this material to influence the survival of these cells in vivo. calculations ...	1978	644654
trypanosoma congolense: thrombocytopenia in experimentally infected cattle.		1978	668836
binding of trypanosoma congolense to the walls of small blood vessels.	the mesenteric microvasculature was studied in rats and rabbits infected with trypanosoma congolense. by examining vessels in the living animals, trypanosomes were observed to adhere to vessel walls by their anterior ends. it was evident from stained preparations of the vessels that the microcirculation contained 4-1400 times as many trypanosomes as were free in the cardiac blood. parasites were more numerous in very small vessels than in larger vessels, and they were clustered in groups within ...	1978	690955
attempted protection of zebu cattle against trypanosomiasis using a multi-stabilate vaccine.	the protective value of double vaccination with 11 recently isolated stabilates of trypanosoma congolense given either as live or dead organisms, followed by trypanocidal therapy, was assessed in zebu cattle subsequently challenged by nine of the original stabilates. both vaccination regimens failed to prevent the animals becoming parasitaemic and eventually succumbing to the infection, although the mean survival times and prepatent periods of the calves which received the live vaccine were long ...	1978	705039
the absence of trypanosoma congolense from the lymph of an infected sheep.	the lymph draining the prefemoral lymph node of a sheep infected with trypanosoma congolense was examined over a period of 10 days. only six trypanosomes were detected in 1500 ml of this fluid during this time, in spite of the animal having about 65,000 organisms/ml in its blood. it is concluded that the suggestion that t congolense is a strict plasma parasite is essentially proven for this specific situation.	1978	705045
the resistance of trypanosoma congolense, t. vivax and t. evansi to human plasma.	tests were made in mice on the resistance of cattle trypanosomes to human plasma. 12 stocks of trypanosoma, congolense were tested' three were fully resistant, eight were moderately or highly resistant, and one was fully sensitive. four stocks of t. vivax were tested; two were fully resistant, one was somewhat resistant, and one was highly sensitive. two stocks of t. evansi were tested; both fully sensitive. the possibility is discussed that t. congolense and t. vivax might produce transient inf ...	1978	705847
diazoniobenzenesulfonate as marker for cell surface proteins: study of the surface coat of trypanosoma congolense.	it is possible to label selectively the surface coat of trypanosoma congolense with radioactive sulfanilic acid diazonium salt. as demonstrated by both sodium dodecylsulfate polyacrylamide gel electrophoresis and isoelectric focusing, radioactivity is incorporated into only one protein, which has a molecular weight of 57 000 and an isoelectric point of 6.25. this indicates that the surface coat of t. congolense is a homogeneous layer, composed of molecules of one type of protein.	1978	711154
the pathogenesis of trypanosoma congolense infection in calves. i. clinical observations and gross pathological changes.	holstein calves infected with trypanosoma congolense treu 112 had intermittent fever, debility and a poor hair coat. at postmortem examination the most significant findings were enlargement of the liver, kidneys and spleen and increased volume of hematopoietic marrow. a group of 13 calves infected for 18 weeks had marked enlargement of lymph nodes throughout the body and hemal nodes were prominent in the sublumbar area caudal to the kidneys. another group infected for 7 weeks had no increase in ...	1978	716157
experimental bovine trypanosomiasis. changes in the catabolism of serum immunoglobulins and complement components in infected cattle.	the turnover of serum proteins of calves experimentally infected with trypanosoma congolense was compared to that of normal uninfected cattle. all proteins examined had much increased catabolic rates in infected animals. in normal animals the average half-lives in days for each protein were: igg1 17.4, igg2 22.4, igm 4.8, iga 3.4, ige 1.9, c1 5.6 and c3 2.9. in trypanosome infected cattle the average half-lives were igg1 1.9, igg2 1.7, igm 0.9, iga 1.2, ige 0.9, c1 1.2 and c3 1.1 days.	1978	721141
experimental bovine trypanosomiasis. changes in serum immunoglobulins, complement and complement components in infected animals.	in three calves experimentally infected with trypanosoma congolense the amounts of igg1 and igg2 were little changed and similar to those of normal animals. igm increased in amount early in the infection and the amount of the increase appeared related to the parasite burden. the amounts of iga and ige were both much decreased and this also appeared related to the numbers of parasites in the blood. there was a decrease in the amounts of total haemolytic complement and complement components c1, c1 ...	1978	721142
lectin analysis of trypanosoma congolense bloodstream trypomastigote and culture procyclic surface saccharides by agglutination and electron microscopic technics.	living, intact bloodstream trypomastigotes and culture procyclic forms of trypanosoma congolense were tested for aggulination with the lectins concanavalin a (con a), phytohemagglutinin p (pp), wheat germ agglutinin (wga), soybean agglutinin (sba), and fucose binding protein (fbp). similar experiments were conducted with living bloodstream and culture forms treated with trypsin or dextranase. parasites were incubated for 30 min at 25 c in various concentrations of each lectin, then examined for ...	1978	739411
the susceptibility of strains of mice to infection with trypanosoma congolense.	the survival times of a number of strains of mice after infection with a stabilate of trypanosoma brucei or of t congolense were examined. the mean survival times of all the strains when infected with t brucei treu 667 ranged from 27 to 63 days. greater disparity was observed after infection with t congolense gvr1 where the mean survival time ranged from seven (balb/c) to 74 days (c57 bl). it is suggested that the c57 bl mouse might provide a laboratory model for the study of trypanotolerance in ...	1978	749094
the pathogenesis of trypanosoma congolense infection in calves. ii. anemia and erythroid response.	the anemia caused by trypanosoma conogolense treu 112 in holstein calves was of moderate severity and normochromic, macrocytic in the acute phase changing to normochromic, normocytic with chronicity. the anemia was hemolytic and responsive as shown by sharply decreased myeloid:erythroid ratio and increased mean corpuscular volume. 51cr red cell labelling studies showed that red cell lifespan was halved in the acute phase and there was an increase in plasma volume. surface organ counting of liver ...	1978	751311
immunologic analysis of host plasma proteins on bloodstream forms of african pathogenic trypanosomes. ii. identification and quantitation of surface-bound albumin, nonspecific igg, and complement on trypanosoma congolense.		1978	98621
susceptibility of inbred strains of mice to trypanosoma congolense: correlation with changes in spleen lymphocyte populations.	a comparison was made of the susceptibility of eight inbred strains of mice to infection with trypanosoma congolense. marked differences in susceptibility as judged by survival were found between the different strains. the capacity of certain strains to survive longer than others appeared to be related to their ability to limit the numbers of trypanosomes in the circulation. there was no difference in the infectivity of t. congolense for mice of high and low susceptibility. furthermore, the find ...	1978	307464
immunosuppression in experimental african trypanosomiasis. polyclonal b-cell activation and mitogenicity of trypanosome-derived saturated fatty acids.	changes in antibody responses in adult mice infected with trypanosoma congolense and subsequently challenged with unrelated antigens (sheep red blood cells and pneumococcal polysaccharide) were studied. immune responses were significantly depressed within 1 week of infection, and complete suppression of both igm and igg responses to both types of antigen was established 15 days after immunization. coincidentally with the development of high parasitaemias, background igm plaque-forming cell respo ...	1979	312771
suppressor cells in trypanosoma congolense-infected mice.	spleen cells from mice infected with t. congolense strongly suppressed lymphocyte stimulation induced in normal spleen cells by incubation with mitogens or allogeneic cells. cell dilution studies showed that suppressor activity was extremely strong. suppressor cell activity was markedly reduced by treatment of spleen cell populations with mitomycin-c and was unaffected by treatment with anti-thy.1 sera and complement. removal of cells which bound carbonyl iron or which bound to nylon columns, de ...	1979	313686
suppression of antibody response to leptospira biflexa and brucella abortus and recovery from immunosuppression after berenil treatment.	zebu cattle infected with either trypanosoma congolense eatro 1800 or trypanosoma vivax eatro 1721 had suppressed humoral immune responses to leptospira biflexa injected intravenously and to attenuated brucella abortus injected subcutaneously. t. congolense infections were more suppressive than t. vivax infections. in cattle infected with t. vivax, the suppression of immune responses to both bacterial immunogens was abrogated when the animals were treated with berenil at the time of antigen admi ...	1979	118933
immune depression in trypanosome-infected mice. ii. characterization of the spleen cell types involved.	spleen cells from trypanosoma congolense-infected mice showed a drastic depression in their capacity to respond to b and t lymphocyte mitogens and to allogeneic spleen cells in mixed lymphocyte cultures. spleen cells from infected mice were also poor stimulators in mixed lymphocyte cultures. the poor responsiveness or stimulation capacity was not due simply to dilution of relevant b or t lymphocytes by the large number of null cells found in the spleens of infected animals. these null cells expr ...	1979	156119
immune depression in trypanosoma congolense-infected mice.		1979	157058
conversion of dihydroorotate to orotate in parasitic protozoa.	the conversion of dihydroorotate to orotate, one of the key reactions in the de novo pyrimidine biosynthetic pathway, has been studied in a number of parasitic protozoa. enzyme activities capable of carrying out this reaction were detected in six members of the kinetoplastida (trypanosoma brucei, trypanosoma congolense, trypanosoma vivax, trypanosoma lewisi, trypanosoma cruzi, leishmania enriettii) and three members of the genus plasmodium (p. knowlesi, p. berghei, p. gallinaceum). the mechanism ...	1979	217438
bovine trypanosomiasis: effect on the immune response of the infected host.	yearling cattle were inoculated with a recently isolated field strain of trypanosoma congolense. dinitrophenylated ovalbumin, a bacteriophage, or bovine parainfluenza-3 virus injected into the cattle during the first 5 weeks of infection resulted in peak serum antibody titers lower but not much lower than those produced by noninfected cattle. primary and secondary antibody responses of inoculated cattle required more time to reach peak titers. peripheral blood lymphocyte concentrations decreased ...	1979	224735
observations on the antigenicity and serological relationships of stocks of trypanosoma congolense from east and west africa.	antigenic relationships of 4 stocks of trypanosoma congolense from different parts of africa were examined by immunofluorescence (ifat) and neutralization tests. antisera to each stock were obtained from rabbits infected with trypanosomes transmitted by glossina morsitans. trypanosomes for use as antigens were obtained from local skin reactions developing on rabbits infected with 2 of the stocks. using the ifat and antisera at end-point dilutions approximately 40% of the trypanosomes fluoresced ...	1979	94428
in vitro binding of trypanosoma congolense to erythrocytes.	trypanosoma congolense broden, an intravascular parasite, binds to vessel walls and erythrocytes of infected hosts. in an attempt to characterize t. congolense adhesion to host cells, an in vitro assay was devised. it was shown in the in vitro experiments that t. congolense binds to bovine, sheep, and goat erythrocytes, but not always to erythrocytes of rats, mice, rabbits, horses or humans. only the anterior part of live trypanosomes adheres to erythrocytes, and the attachment site on the trypa ...	1979	39167
non-specific induction of increased resistance in mice to trypanosoma congolense and trypanosoma brucei by immunostimulants.	administration of the immunostimulants corynebacterium parvum, bacillus calmette-guérin (bcg) or bordetella pertussis prior to, or at the same time as, challenge with trypanosoma congolense significantly increased survival times in mice, both of trypano-susceptible (a/j) and trypano-resistant (c57bl) strains. the increased survival time was associated with significant alterations in parasitaemia, which included lengthening of the pre-patent period, a delay in the time taken to reach the first pe ...	1979	44360
the pathogenesis of trypanosoma congolense infection in calves. iii. neutropenia and myeloid response.	calves infected with trypanosoma congolense treu 112 had, at the onset of anemia, a very low total white cell count and neutropenia but with chronicity there was lymphocytosis. infected calves had a marked reduction in granulocyte mobilization for the first 14 weeks of infection and there was reduced ability to mount an inflammatory response during the onset of anemia. bone marrow aspiration biopsies showed marked erythroid hyperplasia in response to the anemia with a relative and likely absolut ...	1979	380120
the pathogenesis of trypanosoma congolense infection in calves. iv. the kinetics of blood coagulation.	blood coagulation studies showed there was a pronounced thrombocytopenia and hypofibrinogenemia in holstein calves infected with trypanosoma congolense treu 112. there was also ineffective thrombopoiesis characterized by an increased megakaryocytic mass, reduced uptake of 35s-methionine into peripheral blood platelets and a normal platelet lifespan. there was an increased uptake of isotopic label into fibrinogen and a shortened half life indicating a consumptive error with increased peripheral u ...	1979	442453
the pathogenesis of trypanosoma congolense infection in calves. v. quantitative histological changes.	calves infected with trypanosoma congolense treu 112 had generalized microvascular dilation which was most prominent in the liver and the mesentery; there also was increase in cellularity in the lung with significant alveolar thickening and accumulation of hemosiderin-bearing cells in the alveolar septa, focal accumulations of lymphocytes primarily at the corticomedullary junction of the kidneys and a well developed glomerulonephritis, likely membranoproliferative. reticuloendothelial changes we ...	1979	442464
trypanosoma congolense: isolation and purification.		1979	446586
trypanosoma congolense: calf erythrocyte survival.		1979	456461
bovine trypanosomiasis: the red cell kinetics of ndama and zebu cattle infected with trypanosoma congolense.	the responses of susceptible ndama and zebu cattle to needle challenge with trypanosoma congolense were followed using parasitological, haematological and radio-isotopic methods and compared with those of corresponding uninfected animals. in both breeds, infection became patent at the same time but peak parasitaemias were significantly lower, were attained later and were of short duration in the ndama. all infected animals became anaemic, the severity of which correlated with the level and durat ...	1979	481905
inhibition of bovine bone marrow granulocyte/macrophage colony formation in vitro by serum collected from cattle infected with trypanosoma vivax or trypanosoma congolense.	serum collected from cattle infected with trypanosoma vivax or trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in methyl cellulose cultures. maximum inhibition was caused by serum collected two and three weeks post infection. the degree of inhibition appeared to be related to the degree of parasitemia. inhibition of erythroid colony formation by serum collected from these animals was not observed.	1979	483385
trypanosomes in the lymph nodes of cattle and sheep infected with trypanosoma congolense.	the prefemoral lymph nodes of two calves and a sheep infected with a stock of trypanosoma congolense transmitted by glossina morsitans were examined histologically for the presence of trypanosomes. ten days after infection trypanosomes were found in the subcapsular sinuses of the nodes of a calf and the sheep but parasites were absent from the blood at this time. trypanosomes were also detected in the prefemeral lymph node of the other calf on examination 30 days after infection, when parasites ...	1979	504804
trypanosoma congolense: inheritance of susceptibility to infection in inbred strains of mice.		1979	510441
trypanosoma congolense: mechanical removal of the surface coat in vitro.		1979	510443
cyclical transmission of trypanosoma brucei rhodesiense and trypanosoma congolense by tsetse flies infected with culture-form procyclic trypanosomes.	culture procyclic forms of trypanosoma brucei rhodesiense and trypanosoma congolense were fed to glossina morsitans morsitans through artificial membranes. a very high percentage of the flies so fed produced established midgut infections, a proportion of which went on to develop into mature metacyclic trypanosomes capable of infecting mammalian hosts. the method offers a safe, clean way of infecting tsetse flies with african trypanosomes which reduces the need for trypanosome-infected animals in ...	1979	536930
disease syndromes in sheep and goats naturally infected with trypanosoma congolense.		1979	541451
ultrastructural studies of certain aspects of the development of trypanosoma congolense in glossina morsitans morsitans.	the course of trypanosoma congolense infections in glossina morsitans morsitans was followed by electron-microscopic examination of ultrathin sections of the guts and proboscises of infected flies. guts dissected from flies 7 days after infection with culture procyclic forms of t. congolense had heavy trypanosome infections in the midgut involving both the endo- and ectoperitrophic spaces. trypanosomes were also seen in the process of penetrating the fully formed peritrophic membrane in the cent ...	1979	544799
maintenance of infectivity of trypanosoma congolense in vitro with explants of infected skin at 37 degrees c.		1979	555067
distribution and attachment of trypanosoma (nannomonas) congolense in the proximal part of the proboscis of glossina morsitans morsitans.	the distribution and attachment of trypanosoma congolense were investigated in the proximal part of the proboscis of glossina m. morsitans. in the food canal, epimastigotes and trypomastigotes formed tufts or compact layers. trypanosomes were attached to the cuticle by their flagella, which formed zonar hemidesmosomes. the flagella were mostly attached parallel to the axis of the labrum and often pointed to its tip. foot-like processes of the flagella came into contact with adjacent flagella lea ...	1980	6106351
the initial stage of infection with cyclically-transmitted trypanosoma congolense in rabbits, calves and sheep.		1980	6115869
studies on trypanosoma (nannomonas) congolense iv. experimental immunization of mice against tsetse fly challenge.	groups of mice were exposed to multiple bites by tsetse flies (glossina morsitans morsitans) infected with a clone of trypanosoma congolense spread over a periof of 8 days. the mice were subsequently treated with berenil 10 days after the first fly bite as were uninfected control mice. the group of mice which received 12--15 infectious fly bites on two occasions, 21 days apart, were subsequently resistant to infection when re-challenged by flies infected with the same clone of t. congolense. the ...	1980	6155654
isometamidium-dextran complex: toxicity and activity against trypanosoma vivax and trypanosoma congolense in rats and mice.		1980	6156522
studies on glycerol kinase and its role in atp synthesis in trypanosoma brucei.	glycerol kinase of trypanosoma brucei has been shown to be capable of catalysing sn-glycerol-3-phosphate dependent adp phosphorylation for atp generation. the rate of this reaction (vr) is sufficient to account for the observed rate of glycerol production from anaerobic glucose metabolism by intact cells and to account for net atp synthesis. glycerol kinase has been purified by preparing a post-nuclear, particulate fraction and solubilizing the enzyme with 0.5% (w/v) triton x-100. this treatment ...	1980	6258071
depressed immunoconglutinin responses in calves experimentally infected with trypanosoma congolense.	contrary to expectation, immunoconglutinin levels failed to rise significantly in calves infected with trypanosoma congolense. in addition, it was shown that trypanosome infection appeared to inhibit the immunoconglutinin response to brucella abortus strain 19. the possible reasons for these findings are discussed.	1980	6774392
studies on trypanosoma (nannomonas) congolense iii. antigenic variation in three cyclically transmitted stocks.	cyclical transmission of different variable antigen types of trypanosoma congolense stib 228 resulted in the development of metacyclic trypanosome populations which were similar in their variable antigen composition as judged by immunofluorescence and neutralization assays. the variable antigen types present in the ingested bloodstream populations were not found in the metacyclic populations. the bloodstream populations which were obtained from cyclically infected, irradiated (900 rad.) mice con ...	1980	6992057
the quantitation of trypanosoma congolense in calves. iv. in vitro culture of myeloid and erythroid marrow cells.	myeloid and erythroid cultures were prepared from bone marrow aspirates taken from control and t. congolense infected neonatal and six-month-old calves. the aspirates obtained from the infected animals were more cellular than the controls and it was found that the removal of adherent cells prior to ficoll separation improved the sensitivity of the cultures to colony stimulating factors and removed the background connective tissue cells and megakaryocytes from the resulting colonies. there was an ...	1980	7233539
injury induced by trypanosoma congolense adhesion to cell membranes.	trypanosoma congolense binds to erythrocytes and the walls of the microvasculature. experiments were conducted to determine if the attachment of t. congolense, alone or in combination with antitrypanosome antibody, was damaging to host cells. bovine erythrocytes were labelled with 51cr and incubated with t. congolense to promote adhesion. plasma from the same donor as the red blood cells was added to the erythrocyte-trypanosome aggregates and the release of 51cr measured. there was a two- to thr ...	1980	7365637
immunosuppression in bovine trypanosomiasis. the establishment of "memory" in cattle infected with t. congolense and the effect of post infection serum on in vitro (3h)-thymidine uptake by lymphocytes and on leucocyte migration.	cattle infected with trypanosoma congolense were intravenously immunized with leptospira biflexa 15 days after trypanosomal infection. the primary immune response to l. biflexa was considerably reduced as compared to uninfected controls. the infected cattle mounted a secondary response when they were cured of trypanosomes by treatment with berenil 25 days after infection and re-immunized 8 days later. the mean secondary response in these previously infected animals was lower tha, but not signifi ...	1980	7376244
genetic resistance to trypanosoma congolense infections in mice.	the mechanisms of genetic resistance or "trypanotolerance" to infection with trypanosoma congolense were investigated in two strains of mice. one strain c57bl, is outstandingly resistant to most stabilates of t. congolense and can survive for over 80 days, whereas cflp, in common with most other strains, generally succumbs in less than 20 days. evaluation of several pathophysiological and immunological parameters showed that after infection both strains initially developed similar levels of para ...	1980	7380550
hemolytic complement and serum c3 levels in zebu cattle infected with trypanosoma congolense and trypanosoma vivax and the effect of trypanocidal treatment.	total hemolytic complement and c3 levels were found to drop to 6.25% and 50% of preinfection levels, respectively, during trypanosome infections. chemotherapeutic elimination of the trypanosomes with berenil led to recovery of preinfection levels within 7 days and 11 days when cattle infected with trypanosome congolense and trypanosoma vivax, respectively, were treated 37 days after onset of infection. recovery was slower in t. vivax-infected cattle treated on day 50. berenil treatment had no ef ...	1980	7380555
evidence for concanavalin a binding sites on the surface coat of trypanosoma congolense.	glycoproteins of trypanosoma congolense have been detected on sds-polyacrylamide gels using the concanavalin a peroxidase technique. using [35s]diazoniobenzenesulphonate as a marker for cell surface proteins it was possible to distinguish between internal glycoproteins and the surface coat proteins. on sds-polyacrylamide gels con a reacted with the surface coat proteins. results obtained from con a-induced agglutination of living trypanosomes indicated that sugars of the surface coat proteins we ...	1980	7383705
the effect of trypanosoma congolense and t vivax infections on the antibody response of cattle to live rinderpest virus vaccine.	infections with trypanosoma congolense or t vivax did not significantly depress the neutralising antibody response of cattle to live rinderpest vaccine when vaccination was carried out eight or 25 days after infection.	1980	7414077
the quantitation of trypanosoma congolense in calves. 1. hematological changes.	anemia due to trypanosoma congolense infection in neonatal and 6-month-old calves was hemolytic and moderately responsive. the red cells were macrocytic and normochromic in both groups of calves and the anemia was milder in infected neonatal calves compared to the 6-month-old calves. the neonatal calves maintained normal white blood cell counts and developed a lymphocytosis at two weeks of infection. the six-month-old calves developed mild neutropenic leukopenia at one week post-infection withou ...	1980	7414679
inhibition of leukopoiesis by sera from trypanosoma congolense infected calves: partial characterization of the inhibitory factor.	sera collected from calves infected with trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in vitro, but not erythroid colony formation. the inhibitor was found to be tca precipitable in nature and on sephadex g-200 chromatography, it was found to elute with the second major peak. sonicated t. brucei, t. congolense, and t. theileri added directly into the cultures had no effect on granulocyte/macrophage colony formation, but induced significant enhancement of erythr ...	1980	7414680
trypanosoma congolense: specific transformation in vitro of leukocytes from infected or immunized cattle.		1980	7428912
the effects of trypanosoma congolense infection on the testis and epididymis of the goat.		1980	7437534
uptake of purine bases and nucleosides in african trypanosomes.	uptake of radioactivity labelled purine bases and nucleosides by suspensions of trypanosoma brucei and trypanosoma congolense in bicine buffer was determined at 37 degrees c. with t. brucei, the rate of uptake of adenosine was much greater than that of the other compounds tested, the uptake of which decreased in the order adenine, inosine, guanosine and hypoxanthine. with t. brucei, adenosine uptake increased with concentration in a manner suggesting two mechanisms, one with high and the other w ...	1980	7443300
the quantitation of trypanosoma congolense in calves. ii. biochemical changes.	changes in serum electrolytes, osmolality, total proteins and protein fractions, lipid levels and organ function tests were determined in neonatal and 6-month-old calves infected with t. congolense treu 112 and control calves. there were no consistent changes in electrolytes or osmolality for either age group of calves. there was a decrease in total serum protein in the infected 6-month-old calves, caused by decreases in the albumin and beta 2-globulin fractions. the total serum protein level re ...	1980	7445066
the quantitation of trypanosoma congolense in calves. iii. a quantitative comparison of trypanosomes in jugular vein and microvasculature and tests of dispersing agents.	hemocytometer and cytofluorometric methods were used to count trypanosomes in the blood of neonatal and six-month-old calves infected with t. congolense. the correlation between these methods was highest in the six-month-old calves because their parasitemia was greater and the accuracy of cytofluorometric counting is reduced below 1,000 trypanosomes per microliter of blood. fine needle aspiration biopsies showed many trypanosomes marginated in cerebral cortical capillaries, but few in muscle or ...	1980	7445067
purification of the variant antigens of trypanosoma congolense: a new approach to the isolation of glycoproteins.	we describe a new and rapid method for the isolation and purification of the variant antigens of trypanosoma congolense. the procedure consists of (a) partial lysis of trypanosomes with dioxane, (b) lectin-affinity-chromatography with con a-sepharose, (c) electrophoretic desorption and concomitant separation of con a-sepharose-bound glycoproteins in a granulated electrofocusing gel, (d) electrophoretic elution of focused proteins from the granulated gel particles. the efficiency of each step was ...	1981	7236702
[effect of bovine sera on infectivity and pathogenicity of trypanosoma congolense in mice].		1981	7247921
experimental bovine trypanosomiasis (trypanosoma congolense). lack of relation of the level of parasitemia to the j blood group.	twenty-five holstein-friesian steers were experimentally infected with trypanosoma congolense eatro 1721. they were tested for their j blood group status. twelve steers were found to belong to ja blood group and thirteen steers were either js or jcs. the level of parasitemia did not significantly differ between these two groups of cattle. it was concluded that the level of parasitemia is not influenced by j blood group antigens.	1981	7256834
trypanosoma congolense: natural and acquired resistance in the bovine.		1981	7274369
the in vitro response to mitogens of leucocytes from cattle infected with trypanosoma congolense.	the in vitro proliferative response of bovine leucocytes from peripheral blood to lps, pwm and con a was monitored during the course of infection with t. congolense. the stimulatory effect of lps and pwm on pbl was significantly decreased in infected cattle while the reduction of stimulatory response to con a was less marked. there was a high background proliferation of unstimulated leucocytes from infected cattle. this increase in background counts correlated with the parasitaemia in that both ...	1981	7285394
the susceptibility of young sheep and goats to an experimental trypanosoma congolense infection.		1981	7296022
development of local skin reactions in rabbits infected with metacyclic forms of trypanosoma congolense cultured in vitro.		1981	7316583
trypanosoma congolense: surface glycoproteins of two early bloodstream variants. ii. purification and partial chemical characterization.		1981	7318988
sialic acids are responsible for charge heterogeneity of the variant surface glycoprotein of trypanosoma congolense.	intact living cells of trypanosoma congolense can be labeled by periodate/borotritide. the procedure described introduces a radioactive label nearly exclusively into the variant surface glycoprotein (vsg). the label can be removed from the vsg by either neuraminidase treatment or by mild acid hydrolysis. using thin-layer chromatography the labeled compounds comigrated with 5-acetamido [or 5-glycolamide]3,5-dideoxygalactooctulosonic acid and 5-acetamido [or 5-glycolamide]3,5-dideoxyarabinoheptulo ...	1981	7329438
trypanosomiasis in zebu cattle. reappearance of trypanosoma congolense in brain tissue after treatment with berenil.		1981	7335941
the interaction of trypanosoma congolense and haemonchus contortus infections in 2 breeds of goat. 1. parasitology.		1981	7343578
the interaction of trypanosoma congolense and haemonchus contortus infections in 2 breeds of goat. 2. haematology.		1981	7343579
response of the murine lymphoid system to a chronic infection with trypanosoma congolense. i. the spleen.	the response within the different cellular compartments of the spleen in mice infected with trypanosoma congolense was evaluated using histologic and cytologic methods and immunofluorescence to detect intracellular and cell surface immunoglobulin. the isolate of t. congolense used produces a chronic infection in c3h/he mice leading to death 40 to 70 days after inoculation. previous studies had shown that this infection resulted in a marked immunodepression as judged by a range of in vitro assays ...	1981	7033658
antiparasitic structure-activity relationships of congocidine derivatives.	several congocidine analogs were synthesized and tested for in vivo activity against trypanosoma congolense and in vitro activity against amastigotes of leishmania tropica. the tripyrrole derivative, beta-([n-methyl-4-[n-methyl-4-(guanidinoacetamido)pyrrole-2-carboxamido]pyrrole -2-carboxamido]pyrrole-2-carboxamido)butyroamidine dihydrochloride, was less toxic and more active than congocidine. the guanidinoacetyl moiety appears to be a structural requirement for antiparasitic activity in the con ...	1981	6267245