identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of trypanosoma brucei.soluble glycoproteins have been purified from a series of clones of trypanosoma brucei 427. each clone yielded a characteristic predominant glycoprotein which induced clone-specific immunity to trypanosome infection in mice. these glycoproteins were shown by specific labelling and enzyme digestion of cells to be the major components of the trypanosome surface coat. each glycoprotein consisted of a single polypeptide chain having an apparent molecular weight of 65 000 (as measured by sds-polyacry ...1975645
the nad-linked alpha-glycerophosphate dehydrogenase of trypanosomes. 19751018
elevated serum and hepatic tyrosine aminotransferase in voles chronically infected with trypanosoma brucei gambiense. 19763424
a new semi-defined medium for trypanosoma brucei sspp.a new, easy to prepare semi-defined medium for the cultivation of trypanosomes of the t. brucei complex is introduced. containing the two commercially available media mem (minimum essential medium) and medium 199 tc45 as well as 10% inactivated foetal calf serum (fcs), the medium supports optimum growth and direct adaptation of bloodstream forms. growth characteristics, glucose uptake, amino acid utilization and the ultrastructure of trypanosomes grown in this medium are described briefly.197716465
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. ...197716466
factors affecting transmission of vector-borne blood parasites. 197716469
quantitative effects of salycylhydroxamic acid and glycerol on trypanosoma brucei glycolysis in vitro and in vivo.during anaerobic glycolysis in vitro in the presence of salicylhydroxamic acid, trypanosoma brucei brucei converts glucose to equimolar amounts of glycerol and pyruvate as end products. glycerol, whether generated endogenously and pyruvate as end products. glycerol, whether generated endogenously or added exogenously, can inhibit anaerobic glycolysis sufficiently in vitro to result in cell death. the concomitant administration of salicylhydroxamic acid and glycerol to rats infected with t. bruce ...197824994
antigenic variation in trypanosomes. 197827816
royal society of tropical medicine and hygiene, brunel university school of biological sciences 20th april, 1978. abstracts. 197935867
acid hydrolases of trypanosomatid flagellates.homogenates from 5 species of trypanosomatids were screened for the presence of a series of acid hydrolases. the insect flagellae, crithidia sp., contains 5 enzymes reminiscent of plant parasitism, which were absent from or of very low specific activity in parasites of the genera, trypanosoma and leishmania. the latter mammalian parasites, on the other hand, exhibited higher acid proteinase and alpha-d-mannosidase activity levels.197944097
protective immune response in mice immunized with antigens from trypanosoma gambiense-infected mouse blood.immunogenicity and property of antigens obtained from trypanosoma gambiense-infected mouse blood (imp) were examined. a strong vaccine effect against intravenous challenges with 3 x10(3) parasites given on study day 3, 5, or 14 (day 0 = immunization) was observed in mice immunized with a combination of imp (2 mg protein/mouse) and freund's complete adjuvant (fca). but when the challenge was given on day 21 or 30, per cent survival in mice dropped to the 20- and 40-per cent level, respectively. a ...197944619
a pattern in the development of agglutinogenic antigens of cyclically transmitted isolates of trypanosoma gambiense.three isolates of t. gambiense, belonging to 2 serologically different substrains of the species, were cyclically transmitted to rabbits and monkeys by g. morsitans or g. tachinoides. sera collected from the infected animals were tested for agglutinating antibodies to 17 different serotype antigens prepared from rodent-adapted isolates of t. gambiense. the first antibodies detected in sera from all of the animals agglutinated the same serotype antigen l2, indicating that it possibly consisted of ...197549958
["trypanosoma brucei gambiense", antigenic study. iii. hemagglutination reaction with specific antigenic fractions].the tannic acid hemagglutination method was applied to experimentally infected rodents sera. the antigens were trypanosoma gambiense fractions separated by gel filtration on sephadex g 200. two fractions, at least, showed specific activity.197557011
a study of the antigenic relationships of isolates of trypanosoma brucei from three areas in east africa.eleven stabilates of t. brucei, prepared from isolates collected from cattle and tsetse flies in three areas of east africa, were compared serologically by direct agglutination tests, using (a) stabilate-specific antisera prepared in rats and (b)antisera to the predominant variant antigens of each isolate prepared in rabbits. the results indicated that groups of isolates from any one area tended to produce antigens in common, whereas isolates from different areas were generally antigenically dis ...197657741
[antigenic structure of trypanosoma brucei (protozoa, kinetoplastids). immunoelectrophoretic analysis and comparative study]. 197560088
free fatty acids and pathogenesis of african trypanosomiasis. 197766542
free fatty acids, lysophosphatidylcholine, and pathogenesis of trypanosomiasis. 197767408
comparisons of antigenic types of trypanosoma (t)brucei strains transmitted by glossina m. morsitans.a modified infection and maintenance procedure for the cyclical transmission of t. (t.) brucei in glossina m. morsitans is described which produced high mature infection rates in the flies. freshly extruded metacyclic forms and bloodstream forms were serologically typed, using the indirect fluorescent antibody test (ifat) and the neutralization infectivity test (nit). metacyclic forms of a certain strain and its cloned derivative were antigenically homogenous and of the same antigenic type, wher ...197767786
free fatty acids, lysophospholipases, and the pathogenesis of african trypanosomiasis. 197769178
salicylhydroxamic-acid/glycerol in experimental trypanosomiasis. 197771581
evasion of the immune response by parasites. 197560788
free fatty acids, complement activation, and polyclonal b-cell stimulation as factors in the immunopathogenesis of african trypanosomiasis.human and animal forms of african trypanosomiasis are characterised by sustained hypocomplementaemia, gross hypergammaglobulinaemia m, and profound immunosuppression. it is suggested that this hypocomplementaemia is probably due to the action of a trypanosome-derived complement-activating factor and that the elevated igm levels may be the combined result of this decomplementation, together with a subsequent failure of the normal igm-to-igg antibody switch mechanism and polyclonal b-lymphocyte ac ...197772292
lysophospholipases, lipid metabolism, and the pathogenesis of african trypanosomiasis. 197773109
factors controlling igm and igg antibody responses to denatured trypanosome dna.rabbits immunized with complexes of denatured calf thymus dna and methylated bovine serum albumin (mbsa) produced only igm antibodies to denatured dna, confirming the results of previous studies. in contrast, both igm and igg antibodies were induced by mbsa complexes of trypanosoma brucei dna. a similar response was observed by gruenewald and stollar (1973) to t2 bacteriophage dna, in which the normal base cytosine is replaced by hydroxymethylcytosine. t2 bacteriophage dna is known to have a hig ...197658830
antigenic variation in african trypanosomiasis: a memorandum.after reviewing the present knowledge on antigenic variation of the trypanosomes of the trypanosoma (trypanozoon) brucei species, this memorandum discusses the relevance of this phenomenon to the possible development of new tools for trypanosomiasis antigenic variation is related to protective immunity and immunopathology, it is of crucial importance for the feasibility of vaccine development and for treatment principles. it is also of interest as a model for understanding antigenic v ...197774295
ultracytochemistry of the surface coat/pellicle complex in trypanosoma brucei.ultracytochemistry of polysaccharides and specific sugar residues reveals differences in the surface staining pattern between developmental forms of trypanosoma brucei. the techniques used were the pa (periodic acid)-tch (thiocarbohydrazide)-silver albumose reaction for the polysaccharides, and the concanavalin a (con a)-perioxdase-dab coupling method for specific sugar residues. blood and metacyclic forms, both possessing a surface coat, stain distinctly for carbohydrates at the level of the pe ...197551580
immunodepression and the course of infection of a chronic trypanosoma brucei infection in mice.the relationships between course of infection, antigenic variation, and immunodepression of antibody responses to heterologous antigens have been investigated in mice chronically infected with trypanosoma brucei. t. brucei brunel university trypanosomiasis (but) 64 produces a fluctuating parasitaemia lasting about 80 days and ending fatally. it is demonstrated that recurring peaks of parasitaemia are associated with the appearance of new variant antigenic types. at 21 and 31 days of infection, i ...197945126
trypanosoma brucei infection in nude mice: b lymphocyte function is suppressed in the absence of t lymphocytes.b lymphocyte function was assessed in outbred nude mice and nu/+controls infected with trypanosoma brucei brucei. on day 10 of the infection in outbred nu/nu mice in which the initial wave of parasites was strongly controlled, b cell function was unaltered on enhanced compared with uninfected animals or infected nu/+. in other nu/nu mice unable to control the initial parasitaemia, thymidine incorporation and ig secretion by spleen cells were increased on day 10 and their response to lipopolysacc ...197945125
new leads for trypanosomiasis chemotherapy. 197882152
cultivation of vertebrate infective forms derived from metacyclic forms of pleomorphic trypanosoma brucei stocks. short communication. 197944103
crossreacting determinants in the c-terminal region of trypanosome variant surface antigens. 197984339
antigenic analysis by agglutination of trypanosoma brucei brucei parasitemias initiated in mice with in vitro-produced metacyclics.trypanosomes from 14 first-peak parasitemias initiated in mice by injection of in vitro-produced metacyclics were stabilated. strains derived from these stabilates were analyzed for their antigenic composition by cross-agglutination with immune sera produced in rabbits against 12 of the stabilates. the antigenic composition of the 14 stabilates was compared also with two first-peak parasitemias from mice inoculated with fly-derived metacyclics, the variant-specific antigen of the strain used to ...197986245
identification by the blood incubation infectivity test of trypanosoma brucei subspecies isolated from game animals in the luangwa valley, zambia.a total of 7 stocks of trypanosoma brucei subspecies, isolated from naturally infected game animals in the luangwa valley, eastern province, zambia were examined using a modified version of the blood incubation infectivity test (biit). one stock giving consistent biit responses typical of t.b. rhodesiense, was obtained from warthog (phacochoerus aethiopicus). four other stocks, 2 from hyaena (crocuta crocuta), 1 from a waterbuck (kobus ellipsiprymnus) and 1 from a lion (panthera leo) responded l ...197944098
in situ microspectrofluorometry of nuclear and kinetoplast dna in trypanosoma gambiense.using a spectrofluorometer with the zeiss universal micro-spectrophotometer 1 (umsp 1), both nuclear and kinetoplast dna (n-dna and k-dna) in the trypomastigote form of trypanosoma gambiense (strain wellcome) were measured in situ without being extracted. as the fluorescent dye, ethidium bromide was preferably employed because there was a very marked increase in the ethidium fluorescence when the dye was intercalated between the base paires of the dna helix. according to this method, it became p ...197992116
cultivation and in vitro cloning or procyclic culture forms of trypanosoma brucei in a semi-defined medium. short communication. 197943092
evidence for reappearance of trypanosoma brucei variable antigen types in relapse out of 11 bovines infected with different clones of trypanosoma brucei showed 2 peaks of antibody activity against the infecting clone within 7 weeks, as measured by immunofluorescence, radioimmunoassay, and neutralization of infectivity tests. using other clones from an unrelated stock, antibodies to these clones were not detectable, indicating that the antibodies produced were specific to the infecting organisms. these results suggest that there was a reappearance or increase in numbers ...197992560
[serologic differentiation between t. brucei-, t.-congolense- and t-. vivax-infection (author's transl)]. 197994474
adenylate cyclase in bloodstream forms of trypanosoma (trypanozoon) brucei sp.1. the adenylate cyclase in trypanosoma brucei is located in the plasma membrane. 2. a partial kinetic analysis of the properties of the enzyme revealed a km for atp of 1.75 mm and a km for mg2+ of 4mm. 3. at low concentrations, mg2+ activated the enzyme directly in addition to its effect of lowering the concentration of inhibitory free atp species. 4. at high concentrations, mg2+ inhibited the enzyme. furthermore, the enzyme was inhibited at any mg2+ concentration if the concentration of atp ex ...197832875
differential suppression of experimental allergic diseases in rats infected with trypanosomes.pvg/c rats, infected 3 days previously with 10(3) trypanosoma brucei brucei s.42 organisms failed to develop adjuvant disease in response to an intradermal inoculation of mycobacterial adjuvant. by contrast, similarly infected rats, immunized with heterologous brain and spinal cord in freund's complete adjuvant with pertussis vaccine as a secondary adjuvant, developed clinical signs of allergic encephalomyelitis (eae) at least as severe as those in uninfected rats. delayed hypersensitivity react ...197995215
heterophile antibody to red cells in human trypanosomiasis.the heterophile red cell antibodies formed in human trypanosomiasis have been investigated. it has been shown that infection with trypanosoma rhodesiense induces agglutinins reactive with sheep and rabbit red cells, whilst trypanosoma gambiense induces agglutinins which react only with rabbit red cells. both types of antibody can be distinguished from similar antibodies produced by infectious mononucleosis and forssman antigen, and the detection and characterization of the antibodies therefore p ...1978102137
free plasma amino acid profiles of normal and trypanosoma brucei-infected rats. 197831783
growth of infective forms of trypanosoma (t.) brucei on buffalo lung and chinese hamster lung tissue culture cells.infective cultures of trypanosoma (t.) brucei (strain 427) have been initiated and maintained on chinese hamster lung tissue culture cells and buffalo lung tissue culture cells. by changing daily one-third of the rpmi-1640 plus 20% fetal bovine serum medium, the cell numbers can be maintained at 2--4 x 10(6) cells/ml. the cultured trypanosomes on these two tissue culture cell types were infective to mice and morphologically similar to bloodstream slender trypomastigotes in having a subterminal k ...197831773
immunological purification and partial characterization of variant-specific surface antigen messenger rna of trypanosoma brucei brucei.polyadenylated rna isolated from total polyribosomes of two variable antigen types (vats) of t. brucei brucei were shown to program the synthesis, in mrna-dependant reticulocyte lysates, of a wide variety of polypeptides. after immunoprecipitation of these cell-free products with an homologous antiserum raised against purified variant-specific surface antigen (vssa), a major electrophoretic band was apparent on fluorography. it was confirmed that this band corresponds to the variable antigen sin ...1979116191
bruce and the african trypanosomes. 197720787
changes in the kinetic behaviour of threonine transport into trypanosoma brucei elicited by variation in hydrogen ion concentration.1. the dependence of v and v/k(m) for threonine transport into trypanosoma brucei upon the external concentration of h(+) was studied. 2. two ionizing groups, the alpha-amino group of the substrate and a group at the substrate-binding site of the carrier, were found to influence the observed kinetic behaviour of transport. 3. the pk of the group at the substrate-binding site on the free carrier was found to be 6.95 at 30 degrees c and to be temperature-dependent; its heat of ionization was -63.8 ...197718141
[study of chromosome characteristics of artificially-induced ascite tumors].some ascite tumours have been induced in rat by intraperitoneal injection of radlv and in mouse by intraperitoneal injection of radlv, or of protozoa such as trypanosoma brucei and toxoplasma gondii. cytological examination of the resulting ascite tumours has shown that chromosome aberrations were associated with the presence of c and a viral particles.1976134821
electron microscopic observations on structures appearing in trypanosoma gambiense after treatment with neocarzinostatin. 1976140680
experiments on trypanosome transmission by auchmeromyia larvae. preliminary note. 197716472
presence and properties of thymidylate synthase in trypanosomatids.high speed centrifugal supernatant fractions of homogenates of a number of trypanosomatids were assayed for thymidylate synthase (5,10-methylene-tetrahydrofolate: dump c-methyltransferase, ec activity using the method of lomax and greenberg (1967) j. biol. chem. 242, 109-113). similar activities were detected in crithidia fasciculata, crithidia oncopelti, the blood forms of trypanosoma brucei, trypansoma congolense and trypanosoma lewisi and the blood, intracellular and culture forms o ...197714696
pentamidine transport and sensitivity in brucei-group trypanosomes.sensitivity to pentamidine of bloodstream forms and culture forms of trypanosoma brucei brucei, strains of this subspecies, and strains of t. brucei rhodesiense characteristically differs in vitro. analyses of transport parameters for pentamidine uptake in these organisms show differences that correspond with drug sensitivity. long slender bloodstream forms of t. b. brucei have a high affinity for the drug and high rates of uptake at indicated by km and vmax values for 3hpentamidine transport. a ...19766797
[value of cricetomys gambianus in the study of experimental trypanosomiasis from trypanosoma gambiense. methods for mass preparation of antigen and purification of serum exoantigen].methods for mass preparation of crude antigen and exoantigen of trypanosoma gambiense from experimentally infected cricetomys gambianus are described. the size of this animal and the hyperparasitism obtained make it a remarkable source of trypanosomian antigens.1978150933
active-site-directed inhibition of the plasma-membrane carrier transporting short-chain, neutral amino acids into trypanosoma brucei.1. glycine chloromethyl inhibited the active-transport of l-serine into bloodstream forms of trypanosoma brucei. 2. substrates of the short-chain, neutral amino acid transport system (n1), but not of other amino acid transport systems, protected the carrier protein from inhibition. 3. inhibition was never more than 80% complete. the residual activity might have due to a proportion of n1 carrier active sites which had not reacted with the inhibitor. 4. the inhibition was highly selective for the ...19764307
effect of neocarzinostatin on the nucleus, kinetoplast and microtubules of trypanosoma gambiense and trypanosoma evansi.the antibiotic neocarzinostatin (ncs) induces the anucleate form, not the dyskinetoplastic form, of trypanosoma gambiense and trypanosoma evansi. light and electron microscopic studies indicated that production of the anucleate form is due to delay or inhibition of nuclear division. excess pellicular microtubules are formed after treatment of trypanosomes with ncs, suggesting that in trypanosomes the microtubules replicate by induction, not by division. ncs also causes deformation of the axonema ...1978157735
further studies on the metabolism of tryptophan in trypanosoma brucei gambiense: cofactors, inhibitors, and end-products. 1975163748
identification of t. brucei-subgroup strains isolated from game.several t. brucei-subgroup strains isolated from game were investigated with the blood incubation infectivity test (biit) and in human volunteers. original isolates and their clones derivatives were tested. in order to check the validity of the biit, volunteer tested clones were used under modified biit conditions. inoculation of different trypanosome strains into volunteers yielded positive parasitaemia for original isolates from lion, hyaena, and coke's hartebeest. changing antibody titers dur ...19751983
of mice, men, and trypanosomes. 197772203
nucleoside-dependent protein kinase from trypanosoma gambiense.a nucleoside-dependent protein kinase (ec was partially purified from trypanosoma gambiense, the pathogenic agent of sleeping sickness. this enzyme catalyzes the phosphorylation of histone and protamine. various nucleosides at the concentration of 10(-4) m stimulated the histone kinase activity about two-fold, whereas cyclic amp and cyclic gmp were without effect. the ph-optimum for histone phosphorylation was at about ph 7.0. the enzyme activity absolutely depends on mg2+, mn2+ or co2 ...1976177063
stabilization and preservation of the antigenic specificity of trypanosoma (trypanozoon) brucei variant specific surface antigens by mild fixation bloodstream trypansomes fixed by suspension in a 1% formalin solution maintain both their morphology and the immunological specificity of their variant specific surface glycoprotein, so allowing precise identification of the variant types present in a trypanosome population by direct or indirect immunofluorescence combined with phase microscopy. the technique is simple, adaptable to the study of low parasitaemias and should facilitate analysis of the phenomenon of antigenic variation both ...197774941
ablastin in trypanosoma lewisi and related phenomena in other species of trypanosomes. 197554264
multiple protein kinases from trypanosoma gambiense.three protein kinases were distinguished in trypanosoma gambiense extract. the enzymes preferred phosvitin, histone, and protamine as acceptor proteins, respectively. the amino acid residues of the acceptor proteins which were phosphorylated by these protein-kinase activities were serine and- to less extent- threonine. the protein kinase activities were neither affected by cyclic nucleotides nor by cyclic amp receptors. the molecular weights of these protein kinases were determined to be greater ...1978208947
adenosine 3', 5'-cyclic monophosphate-binding proteins from trypanosoma gambiense.two cyclic amp-binding proteins, not identical with regulatory subunits of protein kinases, have been isolated from trypanosoma gambiense. the cyclic amp receptors were separated by gel chromatography on the basis of their molecular weights. the binding constants of the high and the low molecular weight receptors for cyclic amp were determined to be 0.4 mum and 0.6 mum, respectively. cyclic imp and cyclic gmp compete with cyclic amp for the binding sites of both receptors. the cyclic amp binding ...1978208948
identification of the trypanocidal factor in normal human serum: high density lipoprotein.the differentiation of trypanosoma brucei from t. rhodesiense, the causative agent of human sleeping sickness, depends on their relative sensitivities to the cytotoxic effects of normal human serum. the molecule responsible for the specific lysis of t. brucei has now been isolated. serum lipoproteins were fractionated and purified by ultracentrifugal flotation and chromatography on bio-gel a-5m. trypanocidal activity was recovered in the high density lipoprotein fraction (density, 1.063-1.216 g/ ...1978210461
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 ...1979217438
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 ...197944360
tsetse movement in wind fields: possible epidemiological and entomological implications for trypanosomiasis and its control.this paper presents evidence that tsetse flies (glossina) can be dispersed by wind. this dispersal in west africa is suggested to be along a south-west north-east axis. the implications of wind dispersal of glossina for chemical and genetic control operations is discussed. field experiments necessary to test this hypothesis are recommended. a study of human trypanosomiasis foci in west africa has revealed that foci are orientated in roughly parallel lines in a south-west north-east direction. th ...197935935
the natural occurrence of trypanozoon in domestic chicken in the ivory coast.from a natural infected chicken (gallus gallus var. domesticus) in the ivory coast trypanosomes were isolated using mastomys natalensis as recipient animal. trypanosomes were diagnosed as belonging to the subgenus trypanozoon from its morphology and its infectivity for rodents. the stabilated stock was able to infect a laboratory chicken. the stock proved to be human plasma subresistant and showed electrophoretic patterns of three enzymes (alat iii, me i, pep iii) so far only seen in pig and dog ...1979225849
filaments of trypanosoma brucei: some notes on differences in origin and structure in two strains of trypanosoma (trypanozoon) brucei rhodesiense.filaments attached to trypanosomes of two strains of t. (t.) brucei were studied by electron microscopy and two distinct types identified: short-thick and long-thin. the former are associated with stumpy trypanosomes and are secretions, via the flagellar pocket, which originate in the area of the golgi complex, during the infection of the host. they are referred to as 'secretory filaments'. their diameter is 0.09 to 0.14 mum. the long-thin filaments are associated with slender forms of trypanoso ...19768975
development of trypanosoma (trypanozoon) brucei in glossina morsitans inoculated into the tsetse haemocoel.classically, infective development of trypanosoma (trypanozoon) brucei in tsetse flies is thought to take the route crop-midgut-hindgut proventriculus-hypopharynx-salivary gland, where the parasites reach their infective phase. it has been shown experimentally that t. (t.) brucei is capable of developing up to the infective stage in g. morsitans following inoculation of bloodstream form trypanosomes into the haemocoel. the rabbit on which flies were maintained became infected 18 days after expos ...19768974
the synthesis of a variant-specific antigen by trypanosoma brucei in vitro.a variant-specific surface antigen from a cloned population of trypanosoma brucei s42 has been isolated and partially characterized. [35s]l-methionine was found to be incorporated into this material by cells incubated in vitro in a chemically defined medium. incorporation of [35s]l-methionine was inhibited by cycloheximide and puromycin at concentrations which are known to specifically inhibit protein synthesis in other systems. the rate of synthesis of the variant-specific antigen in vitro has ...197765762
immunosuppression in experimental trypanosomiasis: effects of trypanosoma brucei on immunization against louping-ill virus and lymphocytic choriomeningitis virus. 1979232108
a purine nucleoside hydrolase from trypanosoma gambiense, purification and properties.a purine nucleoside hydrolase from trypanosoma gambiense was purified 160-fold. preferred substrates of the reaction were adenosine, inosine and guanosine with a maximum of activity at ph 5.4. competitive inhibitors of the adenosine hydrolysis were dimethylallyl adenosine, 6-methylmercaptopurine riboside, tubercidin, formycin b, 6-mercaptopurine riboside and deoxyadenosine. a metabolic scheme of adenosine nomophosphate salvage synthesis is discussed.1975238316
antigenic variation in trypanosomes. 197774212
trypanosoma brucei: some properties of the cytotoxic reaction induced by normal human serum. 197883247
the blood volumes and erythrokinetics of ndama and zebu cattle experimentally infected with trypanosoma brucei.the responses of susceptible ndama and zebu cattle to experimental infection with trypanosoma brucei were compared using haematological, parasitological and radioisotopic methods. animals of both breeds became anaemic, but this was more severe in the zebu cattle, one of which died. although the prepatent period was the same in animals of both breeds, the levels of the first and subsequent peaks of parasitaemia were higher in the zebu. the anaemia was due to an accelerated rate of red cell break- ...1979262609
a comparative study of the ribonucleic acids of three species of trypanosomatids. 1978299637
detection of multiple variable antigen types in metacyclic populations of trypanosoma brucei.the identification of antigen types in tsetse salivary gland metacyclic populations of trypanosoma brucei requires the production of monospecific antisera to the corresponding bloodstream variable antigen types. monospecific antisera against clones from cyclically transmitted populations are difficult to prepare, however, owing to the antigenic lability of such clones. this problem has been overcome by isolating an antigenically stable clone from a syringe-infected rabbit at a time when its seru ...197989727
suppressor cells and loss of b-cell potential in mice infected with trypanosoma brucei.the functional changes in splenic lymphoid populations from mice infected with t. brucei strain s42 were studied throughout the 3 weeks of infection. within a week of infection, proliferation of b and t cells profoundly increased as shown by 3h-labelled thymidine incorporation and fluorescent staining of surface ig; the spleen cells secreted high levels of both igm and igg immediately cells were put into culture; but with progressing infection this ig production declined. the early effect on t c ...1977302169
human and animal trypanosomiases as world public health problems. 1979117460
adenosine 3',5'-monophosphate in reproducing and differentiated trypanosomes.trypanosoma lewisi, a blood protozoan of rats, undergoes differentiation from a rapidly reproducing form to a nonreproducing form in response to the host antibody ablastin. intracellular concentrations of adenosine 3',5'-monophosphate (cyclic amp), which has been implicated in controlling reproduction in cultured mammalian cells, was measured in the two developmental forms of t. lewisi. the concentrations were significantly different, and the results support a hypothesis under which ablastin sti ...1975171773
crossreacting determinants in variant-specific surface antigens of african trypanosomes.a number of variant-specific surface antigens (vssas) were purified from clones of trypanosoma brucei and t. congolense and tested for immunological crossreactivity. anti-vssa sera were clone-specific when tested by indirect immunofluorescence of living trypanosomes, but they were not clone-specific when tested by radioimmunoassay with purified 125i-labeled vssas. in this double-antibody radioimmunoassay every vssa tested was precipitated by the homologous and all heterologous anti-vssa sera. an ...197877021
localization of glycerol-3-phosphate oxidase in the mitochondrion and particulate nad+-linked glycerol-3-phosphate dehydrogenase in the microbodies of the bloodstream form to trypanosoma brucei. 1977142010
mitogenic activity of an extract of trypanosoma extract obtained by repeated freeze/thawing of a freshly isolated strain of trypanosoma gambiense caused stimulation of lymphocytes obtained from healthy adult donors and from cord blood. the active factor had some stimulatory effect on purified b and t lymphocytes and in two of five subjects increased igm production by lymphocytes cultured in vitro. a trypanosome-derived mitogenic factor may play some part in the pathogenesis of the hypergammaglobulinaemia characteristic of african trypanoso ...1978309195
particle-bound enzymes in the bloodstream form of trypanosoma brucei.we have screened the bloodstream form of trypanosoma brucei for the presence of enzymes that could serve as markers for the microbodies and the highly repressed mitochondrion of this organism. none of seven known microbody enzymes were detected at all, but glycerol-3-phosphate oxidase, atpase, isocitrate dehydrogenase, acid phosphatase and part of the hyperoxide dismutase and malate dehydrogenase activities were found to be particle-bound after fractionation of homogenates by differential centri ...1977195809
isolation and characterization of a new serodeme of trypanosoma rhodesiense.the isolation and characterization of a new serodeme of trypanosoma brucei rhodesiense is described. a clone of organisms derived from a human infection produced chronic infections in mice. additional clones of differing antigenic specificities were isolated from peaks of parasitemia which occurred in these mice. the variable antigen types (vats) of these clones were determined by agglutination, immunofluorescence, and protection of actively immunized mice. thirteen distinct vats were isolated a ...197992203
autoimmune response to dna, red blood cells, and thymocyte antigens in association with polyclonal antibody synthesis during experimental african trypanosomiasis. 1979310833
trypanosomes and experimental trypanosomaisis in east african bats.using the haematocrit centrifuge technique, four hundred and twenty-seven bats from east africa were examined for trypanosome infections. approximately 21% of the bats were found to be infected. the infection rate varied from zero to 73.3%. no trypanosome was found in fruit-eating bats (megachiroptera). three species of trypanosomes were found in insect-eating bats (microchiroptera), none of the trypanosome was infective to mice or rats. the trypanosomes encountered in the survey were trypanosom ...1975239552
the phosphoglucose isomerases of the bloodstream forms of trypanosoma brucei and trypanosoma vivax.1. the phosphoglucose isomerases (pgi's) of the bloodstream forms of trypanosoma brucei and t. vivax have been purified some 150-fold, using cellulose ion-exchange chromatography, gel filtration and isoelectric focussing. 2. the two trypanosome enzymes showed many similarities in kinetic properties, but differed from each other somewhat in thermal stability and in isoelectric point. 3. both trypanosome enzymes differ from pgi's from other sources in having a higher ki for the competitive inhibit ...1978318331
inhibition of protein kinase activity from trypanosoma cruzi and trypanosoma gambiense by 3'-deoxyadenosine.3'-deoxydadenosine was found to be a potent inhibitor of nucleoside-stimulated protein kinase activity from culture forms of trypanosoma cruzi and bloodstream forms of trypanosoma gambiense. the type of inhibition by 3'-deoxyadenosine was competitive with respect to atp. the inhibition constants for 3'-deoxyadenosine were determined to be 0.11mm and 0.085mm for the enzyme from t. cruzi and t. gambiense, respectively. the apparent km value for atp was 0.2mm for both enzymes. 2'-deoxyadenosine was ...1977320116
chemotherapeutically active nitro compounds. 4. 5-nitroimidazoles (part i).more than 135 new 2-methyl-5-nitroimidazoles substituted in 1-position and 1-methyl-5-nitroimidazoles substituted in 2-position were investigated for their activity against various protozoan species, in particular entamoeba histolytica in the golden hamster, trichomonas fetus, trypanosoma brucei and t. cruzi in the nmri mouse. among the nitroimidazoles substituted in the 1-position only two preparations exhibited a similar effect as metronidazole preparations exhibited a similar effect as metron ...1977203293
alteration of free serum amino acids in voles infected with trypanosoma brucei serum amino acid pools of field voles, microtus montanus, were determined over a 24 hr period, and compared to values obtained from voles infected with trypanosoma brucei gambiense. the majority of amino acids in the control animals demonstrated a diurnal variation, peaking predominantly during the dark portion of the photoperiod. this trend was not evident in the infected animals. in addition, infected voles possessed an apparent state of hypoaminoacidemia, with levels of threonine, serine ...1977321737
effect of chronic trypanosoma brucei infection on the course of louping ill virus infection in mice.the course of louping-ill virus infection in mice chronically infected with trypanosoma brucei was investigated. the mean survival time of mice infected with virus alone was 10.2 days, compared to 12.8 days in mice infected with t. brucei 14 days before virus challenge, and the cumulative mortality in the two groups was 62.5 and 90%, respectively. virus was only inconsistently detected in the blood of mice given virus alone but was regularly present at high titers for up to 12 days in the blood ...1979217825
determination of igg antibodies produced by the kinetoplast fraction antigens of trypanosoma rhodesiense, t. vivax and t. brucei by enzyme linked immunosorbent assay.antibodies to trypanosome homegenate and subcellular particles of different trypanosome species, with emphasis on the kinetoplast fraction, were measured by the elisa method. the antibodies formed to these homogenates and subcellular particles could be titrated; the kinetoplast fraction, particularly, not only gave titration against a heterologous strain, but also showed activity against this strain after two to three antigenic variations.1977327720
acquisition by trypanosoma brucei brucei of potential infectivity for man by passage through birds. 197876270
detection of antibodies in trypanosome-infected cattle by means of a microplate enzyme-linked immunosorbent assay.a micromodification of the enzyme-linked immunosorbent assay (elisa) was evaluated for its potential application in the immunodiagonsis of bovine trypanosomiasis. serum samples from infected and non-infected zebu cattle and samples from friesian cattle with experimental infections were exmained for the presence of trypanosomal antibodies. there were significant differences between the microelisa values obtained with samples from infected and non-infected cattle. during the course of infection mi ...1977333677
[indirect immunofluorescence study of 200 cases of tryponosomiasis due to trypanosoma gambiense].the sera and csf collected on 200 patients suffering from sleeping sickness were collected before treatment and tested with fluorescent antibody test. the proportion of strongly positive sera is very important in the first period and decreases progressively with the alteration of csf. this shows the reliability of the fat technique as a screening method because it is in the first period that it is difficult to diagnose the disease. 14% of csf collected during the 1st period are positive with fat ...1977338173
free amino acids in brain, liver, and skeletal muscle tissue of voles infected with trypanosoma brucei gambiense.the concentrations of several acidic and neutral amino acids of brain, liver, and skeletal muscle were determined in field voles, microtus montanus, and compared to values obtained from voles harboring a chronic infection of trypanosoma brucei gambiense. all of the amino acids examined were found at comparable levels in brain tissue from both groups of animals with the exception of tyrosine, which was reduced by approximately 45% in the infected voles. similarly, the only difference noted in liv ...1977338875
trypanosoma brucei: detection of low parasitaemias in mice by a miniature anion-exchanger/centrifugation technique.a method is described for the detection of trypanosomaemia in mice using the samples of about 55 microliter of blood which can be readily obtained from mice by puncture of the retro-orbital plexus with heparinized glass microhaematocrit tubes. the samples, mixed with an appropriate diluent, are passed through small (2 ml) anion-exchanger columns by means of peristatic pumps and the eluates collected in tubes which can be centrifuged so as to concentrate any organisms in the terminal part of the ...1977339422
the resistance to human plasma of trypanosoma brucei, t. rhodesiense and t. gambiense: iii. clones of two plasma-resistant strains.tests for resistance to human plasma were made on six clones of a stabilate of trypanosoma rhodesiense (lump 10) which was calculated to contain about 3,000 resistant trypanosomes per million. two of the clones were not resistant and four were only subresistant. tests were also made on 12 lines (clones) of a stabilate of polymorphic trypanosomes isolated from tsetse flies. one of them, etat 10, had infected a laboratory worker and was found to be fully resistant to human plasma; the other lines ...1977339423
immunoprophylaxis against african trypanosomiasis. 1977339684
the liverpool school of tropical medicine expedition to senegambia, 1902, as revealed in the letters of dr. j. l. todd. 1977339854
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