| short-term metabolism of (14-c) tryptophan in rats infected with trypanosoma brucei gambiense. | the pathways of short-term tryptophan metabolism in rats infected with trypanosoma brucei gambiense were studied to determine whether this amino acid undergoes rapid conversion to tryptophol and indole lactic acid, two metabolites produced in vitro by t. brucei gambiense. intravenously administered l-(3-14-c)-tryptophan was metabolized to at least two compounds in infected rats: tryptophol (indole ethanol) and indole acetic acid. indole lactic acid was not detected as a metabolite. approximately ... | 1975 | 1117200 |
| efffects of trypanosoma brucei gambiense infection on incorporation of 14c-tryptophan by microtus montanus. | | 1975 | 1117356 |
| protein uptake and digestion in bloodstream and culture forms of trypanosoma brucei. | the mechanisms of ferritin uptake and digestion differ in bloodstream and culture forms of trypanosoma brucei. ferritin enters bloodstream forms from the flagellar pocket by pinocytosis in large spiny-coated vesicles. these vesicles become continuous with straight tubular extensions of a complex, mostly tubular, collecting membrane membrane system where ferritin is concentrated. from the collecting membrane system the tracer enters large digestive vacuoles. small spiny-coated vesicles, which ... | 1975 | 1117436 |
| experimental brucei trypanosomiasis: immunosuppression of the blood-aqueous barrier. | | 1975 | 1122948 |
| trypanosoma gambiense: blocking ability of parasite and macrophage homogenates on attachment during phagocytosis. | | 1975 | 1123016 |
| mitochondrial and cytoplasmic ribosomes and their activity in blood and culture form trypanosoma brucei. | ribosomes of trypanosoma brucei, a parasitic, flagellated protozoan (order kinetoplastida), were identified on sucrose density gradients by their radioactively labeled nascent peptides. ultraviolet absorption revealed only cytoplasmic ribosomes which served as internal sedimentation markers. synthesis on cytoplasmic ribosomes was completely inhibited by cycloheximide. in the presence of this antibiotic, nascent peptides were associated with ribosomes of lower sedimentation coefficient than the c ... | 1975 | 1127006 |
| pathogenesin of trypanosoma brucei infection is sheep. i. clinical signs. | | 1975 | 1127150 |
| pathogenesis of trypanosoma brucei infection in sheep. ii. cerebro-spinal fluid changes. | | 1975 | 1127151 |
| pathogenesis of trypanosoma brucei infection in sheep. iii. hypophysial and other endocrine lesions. | | 1975 | 1127152 |
| the number and morphology of trypanosomes in the blood and lymph of rats infected with trypanosoma brucei and t. congolense. | the thoracic lymph duct of rats infected with trypanosoma brucei and with t. congolense was cannulated at different stages of infection. trypanosomes were always present in the lymph of rats infected with t. brucei, wheras they were absent or very scarce in the lymph of rats infected with t. congolense. there were greater fluctuations in the numbers of trypanosomes in the blood than in the lymph. the intra- and extravascular populations of t. brucei differed: stumpy forms were present only in ... | 1975 | 1128927 |
| the cause of death in acute murine trypanosomiasis. | | 1975 | 1145717 |
| pedigrees of the edinburgh trypanosoma (trypanozoon) antigenic types (etat). | | 1975 | 1166492 |
| a case of congenital trypanosomiasis in lagos. | a 17-day old baby girl presented with signs and symptoms of neonatal meningitis, except that she did not respond to the usual drugs. intensive investigations showed that she had trypanosomal meningo-encephalitis or sleeping sickness. her csf was full of t. gambiense. her mother's blood, but not her csf, also contained the parasites. the clinical features and laboratory findings of the disease in this neonate were very different from those usually found in adults. furthermore, her infection was c ... | 1975 | 1170654 |
| carbon dioxide fixation in trypanosomatids. | fixation of carbon dioxide has been demonstrated for extracts from crithidia fasciculata, trypanosoma mega and trypanosoma brucei brucei bloodstream and culture forms. the enzymes involved in this fixation were found to be adp-stimulated phosphoenolpyruvate carboxykinase (e.c. 4.1.1.32), 'malic' enzyme (e.c. 1.1.138-40) and pyruvate carboxylase (e.c. 6.4.1.1). the subcellular localization of these enzymes has been investigated in all three organisms. products of short and long term fixation expe ... | 1975 | 1178224 |
| utilization of amino acids by trypanosoma brucei in culture: l-threonine as a precursor for acetate. | the amino acid compositions of several culture media have been analysed and compared. the utilization and excretion of amino acids and other metabolites have been followed during growth of trypanosoma brucei s42 in a defined medium. all of the added l-threonine was metabolized by the cells, even when it was present at elevated concentrations. glucose was consumed throughout the growth cycle: glutamine was consumed more rapidly than glutamic acid, which was itself used at about the same rate as p ... | 1975 | 1187188 |
| [serological studies on subgenus-differentiation and persistence of antibodies following infections with trypanosomes (author's transl)]. | 10 cattle were infected or superinfected with trypanosoma species of the subgenera nannomonas (t. congolense), duttonella (t. vivax) and trypanozoon (t. brucei) respectively. the complement fixation test (ctf) and the indirect fluorescent antibody test (ifat) were employed to investigate the possible differentiation of subgenera by serological methods and the persistence of antibodies. the serological results were compared with those of parasitological and hematological findings. after monospeci ... | 1975 | 1189021 |
| [comparative immunoelectrophoretic analysis of culture and bloodstream forms of "trypanosoma" (trypanozoon) brucei gambiense". demonstration of stage and antigenic type specific antigens (author's transl)]. | the comparative immunoelectrophoretic analysis of the antigenic structures of culture and bloodstream forms with cross absorption tests confirm the existence among trypanosoma gambiense antigens of: --numerous antigenic components common to culture and bloodstream forms;--several antigenic components specific of either culture forms or bloodstream forms. among the latter, two components are shown to be specific of the antigenic type and appear to support the immunochemical specificity of each va ... | 1975 | 1190743 |
| comparative responses of radioattenuated trypanosoma brucei and t. congolense in rats. | | 1975 | 1195068 |
| quantitative ultrastructural investigations of the life cycle of trypanosoma brucei: a morphometric analysis. | the quantitative ultrastructure of the developmental stages of trypanosoma brucei brucei in its vector glossina morsitans was studied by morphometric analysis. values from ectoperitrophic midgut forms, proventricular forms, epimastigote and metacyclic forms in the salivary gland are compared with results from bloodstream forms, published previously. significant differences in the volume densities of the trypanosome's single mitochondrion, of microbody-like organelles and in the surface densities ... | 1975 | 1195156 |
| pathology of chronic trypanosoma bruceï-infection in the rabbit. | | 1975 | 1199539 |
| penetration of mid-gut cells of glossina morsitans morsitans by trypanosoma brucei rhodesianse. | | 1975 | 1202348 |
| pathogenesis of the anemia in african trypanosomiasis: characterization and purification of a hemolytic factor. | acute anemia is a major feature of african trypanosomiasis. it has been shown to be of hemolytic nature. hemolytic substances were found in serum from infected animals as well as in supernatant of trypanosome suspensions. a hemolytic pronase-sensitive factor of about 10000 m.w. has been purified from such supernatants. | 1975 | 1209223 |
| electrocardiographic changes in african trypanosomiasis caused by trypanosoma brucei rhodesiense. | the electrocardiographic findings in 40 patients with trypanosoma brucei rhodesiense infection are reported. using rigid diagnostic criteria 7 out of 18 patients (39%) had abnormal electrocardiograms before any form of therapy and 22 of the 40 patients (55%) had abnormal electrocardiograms at some stage of the disease or its treatment. the electrocardiographic abnormalities are described and discussed and the literature is reviewed. | 1975 | 1216299 |
| antigenic variation in syringe passaged populations of trypanosoma (trypanozoon) brucei. 1. rationalization of the experimental approach. | | 1975 | 1231658 |
| antigenic variation in syringe passaged populations of trypanosoma (trypanozoon) brucei. ii. comparative studies on two antigenic-type collections. | | 1975 | 1231659 |
| studies on the anaemia in experimental african trypanosomiasis. 1. a preliminary communication on the mechanism of the anaemia. | | 1975 | 1231661 |
| [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 |
| ocular lesions in experimental trypanosoma brucei infection in cats. | experimental trypanosoma brucei-infection progressing clinically peak-wise, induces intense proteinleakage in the anterior chamber of cats' and dogs' eyes, with a cyclitislike symptomatology, preceded by hypersensitivity of conjunctiva and respiratory mucosae, together with lacrimation, and facial oedema. the pherogram of aqueous humor is the replica of the serumpherogram at the endstage of the disease and is identical to secondary aqueous. absence of any significant changes in serumproteins, im ... | 1975 | 1239181 |
| proceedings: macrophage-cytophilic antibodies in trypanosome infections in mice. | | 1975 | 1240667 |
| [preparation of a standardized antigenic extract from several strains of african trypansomes]. | the preparation of a soluble antigen from african trypanosomes is described below. it is important to observe the following steps: --minimal dose of the phytohemagglutinin must be placed in rapid contact with the trypanosomes; --the standard speed of the different centrifugations must be strictly observed; --a thorough washing of the trypanosomes must be carried out to eliminate the hetero-antigens, but caution should be excercised, as over washing is harmful to the trypanosomes. | 1975 | 1242121 |
| effect of hydroxystilbamidine on the kinetoplast of trypanosoma gambiense in mice. | hydroxystilbamidine (ohsa), an inhibitor of dna synthesis, was shown to induce the dyskinetoplastic forms (akinetoplastic forms, ak forms) of trypanosoma gambiense. the mode of appearance of the ak forms after injection of various doses of ohsa into infected mice was examined. the results suggested that production of the ak form is due to the selective inhibition of kinetoplast duplication of the drug without any effect on nuclear and cytoplasmic multiplication. when the parasites were treated w ... | 1975 | 1243650 |
| the potential use of inhibitors of glycerol-3-phosphate oxidase for chemotherapy of african trypanosomiasis. | | 1976 | 1253981 |
| immunity to monomorphic trypanosoma brucei: humoral response. | trypanosome-agglutinating antibodies, predominantly of the igm class, are formed in t. brucei-infected rats cured with berenil (diminazene). the duration of berenil prophylaxis following administration of a minimum curative dose is approximately 28 days. rechallenge of drug-cured animals with homologous organisms results in the production of igg, indicating an apparent absence of interference under these conditions with b-cell, t-cell cooperativity. | 1976 | 1255367 |
| observations on a herd of beef cattle maintained in a tsetse area. ii. assessment of the development of immunity in association with trypanocidal drug treatment. | three groups of boran cattle were maintained under different trypanocidal drug regimes for 29 months in an area of "medium" tsetse challenge. the development of immunity to trypanosmiasis in the cattle was assessed on the basis of changes in trypanocidal drug requirement, development of parasitaemia, ability to maintain normal blood values, growth and response to challenge after the withdrawal of the drugs. observations were also made on serum antibody content by immunofluorescence and on serum ... | 1976 | 1258147 |
| lipid content of the slender and stumpy forms of trypanosoma brucei rhodesiense: a comparative study. | | 1976 | 1261236 |
| induction of immunity in rodents receiving living drug-treated trypanosomes. | | 1976 | 1262128 |
| algorithms in the diagnosis and management of exotic diseases. xi. african trypanosomiases. | | 1976 | 1262714 |
| pentamidine transport in trypanosoma brucei-kinetics and specificity. | | 1976 | 1267824 |
| correlation of autoantibody titres with central nervous system pathology in experimental african trypanosomiasis. | cd-1 mice infected with the protozoan parasite trypanosoma brucei brucei developed few signs of central nervous system pathology associated with the invasion of the central nervous system by these parasites and did not survive beyond 5-6 weeks with deaths common before this time point. however, use of the trypanocidal drug diminazene aceturate (40 mg/kg), which fails to cross the blood-brain barrier, on day 21 post-infection led to the development of central nervous system pathology similar to t ... | 1992 | 1281824 |
| distribution of filipin-sterol complexes in the bloodstream form of trypanosoma brucei gambiense. | the polyene antibiotic, filipin, was used as a probe for demonstrating sterols in the plasma membrane of trypanosoma brucei gambiense. three different regions of the continuous plasma membrane over the cell body proper, flagellar pocket, and flagellum, were compared as to density and distribution of the filipin-sterol complexes by freeze-fracture method. the density of the complexes was highest in the cell body membrane and lowest over the flagellar pocket. the filipin-sterol complexes in the ce ... | 1992 | 1285810 |
| direct isolation in vitro of trypanosoma brucei from man and other animals, and its potential value for the diagnosis of gambian trypanosomiasis. | a recently described simple kit for isolating african trypanosomes in vitro (kivi) was tested further with blood samples from man and other animals in côte d'ivoire and république du congo. a high rate of success was achieved, with positive cultures being found 5-36 d after inoculation. the method was also of value in diagnosis. parasitaemia was initially detected by the haematocrit method; in addition, the mini-anion exchange column was used for human blood and lymph fluid from patients with sw ... | 1992 | 1287920 |
| the use of the acridine orange qbc technique in the diagnosis of african trypanosomiasis. | | 1992 | 1287921 |
| screening for trypanosoma brucei gambiense antibodies with the indirect fluorescent antibody test (ifat). effect of age and previous treatment. | this paper reports on some of the findings of a longitudinal multi-round investigation into the predictive power of early signs and symptoms of human african trypanosomiasis caused by t.b. gambiense, in the rural health zone of kasongo (maniema, zaire). it assesses the importance of the effect of age and a history of previously treated sleeping sickness on serological positivity as measured by the indirect fluorescent antibody test (ifat), used as a screening test. the impact of including age an ... | 1992 | 1292423 |
| [electroencephalographic study of trypanosomes in meningoencephalitic stage of human african trypanosomiasis from trypanosoma brucei gambiense before and after treatment with dl-alphadifluoromethyl- ornithine hydrochloride monohydrate (dfmo)]. | the aim of the study was to assess effects of dfmo (an inhibitor of polyamine biosynthesis) on waking electroencephalogram (eeg) of 25 patients at meningoencephalitic stage of human african gambiense trypanosomiasis (hat), six of whom having been previously treated with and considered refractory to melarsoprol. dfmo was administered intravenously at dose of 400 mg/kg/day for 14 days, followed by oral treatment at dose of 300 mg/kg/day for 21 days. eeg data were performed before, then 15 days aft ... | 1992 | 1292798 |
| an in vitro bioassay for quantification of melarsoprol in serum and cerebrospinal fluid. | a biological assay was developed for measuring melarsoprol in serum and cerebrospinal fluid of patients with human african trypanosomiasis. trypanosomes were cultivated in microtiter plates for 72 hours with melarsoprol (mel b) in concentrations of 1.25 micrograms/ml to 2.2 ng/ml. the minimum inhibitory concentration of mel b for a reference trypanosoma brucei rhodesiense clone was determined by microscopical examination. samples of serum or cerebrospinal fluid were incubated under the same cond ... | 1992 | 1293724 |
| preliminary observations on the efficacy of mel cy (cymelarsan) in domestic animals infected with stocks of trypanosoma brucei brucei and t.b. evansi. | the trypanocidal activity of an arsenical compound (rm 110; mel cy; cymelarsan) was evaluated against trypanosoma brucei brucei and t. brucei evansi in cultures, in goats and pigs. the trypanosome stocks used differed in their levels of susceptibility to cymerlarsan in an in vitro test, their ic50 values (drug concentration which inhibits growth by 50%) ranging from 4.8-5.1 nm for susceptible, and 26.9 nm for a resistant stock. goats infected with a susceptible t.b. evansi stock were cured after ... | 1992 | 1293725 |
| genital lesions and histopathology of male guinea-pigs infected with trypanosomes. | sixty adult male guinea-pigs were used to study the effect of trypanosoma brucei brucei and trypanosoma congolense infections on genitalia, testicles and reproductive capacity. both infections showed acute to chronic courses. t. b. brucei appeared more virulent than t. congolense. in both cases the infection periods significantly (p < 0.01) influenced resultant decrease in body and gonadal weight, testicular mass index and extent of lesion formation. histopathological lesions included mononuclea ... | 1992 | 1298022 |
| evaluation of mono- and polyclonal antibody-based antigen detection immunoassays for diagnosis of trypanosoma evansi infection in the dromedary camel. | two enzyme-linked immunosorbent assays (elisa), one based on a mouse anti-trypanosoma brucei group-specific monoclonal antibody and the other on rabbit anti-trypanosoma evansi polyclonal antibodies, have been evaluated for their ability to detect circulating trypanosome antigens in camel sera as a means for the diagnosis of t. evansi infections. all 91 sera from a negative control camel herd from kenya gave negative antigen-elisa results in the monoclonal antibody-based elisa and only 2 of them ... | 1992 | 1301627 |
| structure of the complex between trypanosomal triosephosphate isomerase and n-hydroxy-4-phosphono-butanamide: binding at the active site despite an "open" flexible loop conformation. | the structure of triosephosphate isomerase from trypanosoma brucei complexed with the competitive inhibitor n-hydroxy-4-phosphono-butanamide was determined by x-ray crystallography to a resolution of 2.84 a. full occupancy binding of the inhibitor is observed only at one of the active sites of the homodimeric enzyme where the flexible loop is locked in a completely open conformation by crystal contacts. there is evidence that the inhibitor also binds to the second active site of the enzyme, but ... | 1992 | 1304889 |
| galactose-containing glycosylphosphatidylinositols in trypanosoma brucei. | many eukaryotic surface glycoproteins, including the variant surface glycoproteins (vsgs) of trypanosoma brucei, are synthesized with a carboxyl-terminal hydrophobic peptide extension that is cleaved and replaced by a complex glycosylphosphatidylinositol (gpi) membrane anchor within 1-5 min of the completion of polypeptide synthesis. we have reported the purification and partial characterization of candidate precursor glycolipids (p2 and p3) from t. brucei. p2 and p3 contain ethanolamine-phospha ... | 1992 | 1309774 |
| domain structure of u2 and u4/u6 small nuclear ribonucleoprotein particles from trypanosoma brucei: identification of trans-spliceosomal specific rna-protein interactions. | maturation of mrnas in trypanosomes involves trans splicing of the 5' end of the spliced leader rna and the exons of polycistronic pre-mrnas, requiring small nuclear ribonucleoproteins (snrnps) as cofactors. we have mapped protein-binding sites in the u2 and u4/u6 snrnps by a combination of rnase h protection analysis, native gel electrophoresis, and cscl density gradient centrifugation. in the u2 snrnp, protein binding occurs primarily in the 3'-terminal domain; through u2 snrnp reconstitution ... | 1992 | 1310147 |
| kinetoplast dna and molecular karyotypes of trypanosoma evansi and trypanosoma equiperdum from china. | we compared 12 stocks of trypanosoma evansi and 1 recently isolated stock of trypanosoma equiperdum from different regions of china by analysis of kinetoplast dna (kdna), nuclear dna and molecular karyotypes. the t. equiperdum stock was remarkably similar to the t. evansi stocks, except for the possession of kdna maxi-circles, suggesting a very close evolutionary relationship between t. evansi and t. equiperdum. the maxi-circles of the chinese t. equiperdum stock were approximately 14.3 kb in si ... | 1992 | 1311051 |
| the major cysteine proteinase (cruzipain) from trypanosoma cruzi is encoded by multiple polymorphic tandemly organized genes located on different chromosomes. | we demonstrate that cruzipain, the major cysteine proteinase of trypanosoma cruzi epimastigotes, is encoded by a large number of tandemly arranged genes. restriction enzyme analysis of 20 clones containing complete repeat units of the gene, as well as sequencing of 2 of these clones, and comparison with previously published partial sequences, indicated that the sequence is conserved among the repeat units, although polymorphisms clearly exist. the repeat units contain an intergenic region of 528 ... | 1992 | 1311053 |
| plasmodium falciparum and plasmodium chabaudi: characterization of glycosylphosphatidylinositol-degrading activities. | merozoites of malaria parasites have a membrane-bound serine protease whose solubilization and subsequent activity depend on a parasite-derived glycosylphosphatidylinositol-phospholipase c (gpi-plc). the gpi-degrading activities from both plasmodium falciparum and plasmodium chabaudi have been characterized and partially purified by phenylboronate chromatography. they are membrane-bound, developmentally regulated, calcium-independent enzymes and as such they resemble gpi-plc of trypanosoma bruce ... | 1992 | 1317298 |
| site of palmitoylation of a phospholipase c-resistant glycosylphosphatidylinositol membrane anchor. | the site of palmitoylation of the phosphatidylinositol moiety of the glycosyl-phosphatidylinositol membrane anchor of trypanosoma brucei procyclic acidic repetitive protein was studied by using periodate oxidation. analysis of the products by g.c.-m.s. allowed the assignment of 40 and 60% of the palmitate to the 2-position and the 3-position respectively of the myo-inositol ring. | 1992 | 1318027 |
| dna comparisons of trypanosoma evansi (indonesia) and trypanosoma brucei spp. | two clones from separate isolates of trypanosoma evansi in indonesia were found by polymerase chain reaction (pcr) analyses to contain 3 different repeated nuclear dna sequences of trypanosoma brucei spp: the consensus sequence for a highly repetitive 177 base pairs and the gene repeats encoding procyclin and the spliced leader. in addition, the 994 bp minicircle sequence of one of the clones was determined, and pcr amplification primers specific for minicircles of t. evansi were identified that ... | 1992 | 1319564 |
| a ribosomal rna gene promoter at the telomere of a mini-chromosome in trypanosoma brucei. | the parasitic protozoan trypanosoma brucei has some hundred mini-chromosomes of 50-150 kb, which mainly consist of telomeric repeats, sub-telomeric repeats and internal 177-bp repeats. their primary function seems to be to expand the repertoire of non-transcribed sub-telomeric variant surface glycoprotein (vsg) genes. here we report that two of the smaller mini-chromosomes (55 and 60 kb) contain sequences homologous to the ribosomal rna gene promoter region. we have targeted by homologous recomb ... | 1992 | 1319572 |
| pathogenesis of trypanosomiasis-induced glomerulonephritis in mice. | we investigated the pathogenesis of glomerulonephritis in mice that had been infected with trypanosoma brucei. polyclonal b cell activation was evaluated, with special attention to the presence of autoantibodies, which are known to be involved in other models for glomerulonephritis. the balb/c mice studied developed severe albuminuria. light-microscopy of the kidneys showed increase of mesangial matrix and thickening of the glomerular capillary walls. immunofluorescence studies showed immunoglob ... | 1992 | 1320230 |
| an inositol phosphate glycan derived from a trypanosoma brucei glycosyl-phosphatidylinositol mimics some of the metabolic actions of insulin. | some of the acute actions of insulin may be mediated by an enzyme-modulating inositol phosphate glycan, produced by the insulin-sensitive hydrolysis of glycosyl-phosphatidylinositol (gpi) that is structurally similar to a membrane protein anchor. an inositol glycan fragment from the structurally characterized trypanosoma brucei variant surface glycoprotein gpi anchor is evaluated for insulin-mimetic antilipolytic activity. the fragment specifically and dose-dependently inhibits isoproterenol-sti ... | 1992 | 1322896 |
| inhibition of the glcnac transferase of the glycosylphosphatidylinositol anchor biosynthesis in african trypanosomes. | a wide variety of eukaryotic membrane proteins are anchored to the cell surface by a covalent linkage to glycosylphosphatidylinositol. one of the best characterised examples is the variant surface glycoprotein of the protozoan parasite, trypanosoma brucei. the pathway for the formation of the glycosylphosphatidylinositol precursor has been previously described, with the first step being the transfer of glcnac, from udp-glcnac to endogenous phosphatidylinositol to form n-acetyl-glucosaminylphosph ... | 1992 | 1325903 |
| the mitochondrion in bloodstream forms of trypanosoma brucei is energized by the electrogenic pumping of protons catalysed by the f1f0-atpase. | bloodstream forms of trypanosoma brucei were found to maintain a significant membrane potential across their mitochondrial inner membrane (delta psi m) in addition to a plasma membrane potential (delta psi p). significantly, the delta psi m was selectively abolished by low concentrations of specific inhibitors of the f1f0-atpase, such as oligomycin, whereas inhibition of mitochondrial respiration with salicylhydroxamic acid was without effect. thus, the mitochondrial membrane potential is genera ... | 1992 | 1327770 |
| cytochrome c reductase purified from crithidia fasciculata contains an atypical cytochrome c1. | cytochrome c reductase purified from the trypanosomatid crithidia fasciculata retained antimycin a sensitivity and catalyzed the reduction of horse heart ferricytochrome c in the presence of reduced coenzyme q10. the complex contained heme b and heme c1 in a ratio of 2:1. nine major protein bands ranging in size from 55.3 to approximately 12.8 kda were resolved by sds-polyacrylamide gel electrophoresis. a 31.6-kda protein was identified as cytochrome c1 by the presence of a covalently attached h ... | 1992 | 1328195 |
| biosynthesis of glycolipid precursors for glycosylphosphatidylinositol membrane anchors in a toxoplasma gondii cell-free system. | toxoplasmosis, a disease that affects humans and a wide variety of mammals is caused by toxoplasma gondii, the obligate intracellular coccidian protozoan parasite. most t. gondii research has focused on the rapidly growing invasive form, the tachyzoite, which expresses five major surface proteins attached to the parasite membrane by glycosylphosphatidylinositol (gpi) anchors. we have recently reported the purification and partial characterization of candidate precursor glycolipids (gpis) from me ... | 1992 | 1328232 |
| native mrna editing complexes from trypanosoma brucei mitochondria. | the aim of this study was to identify multicomponent complexes involved in kinetoplastid mitochondrial mrna editing. mitochondrial extracts from trypanosoma brucei were fractionated on 10-30% glycerol gradients and assayed for rnas and activities potentially involved in editing, including pre-edited mrna, guide rna (grna), endonuclease, terminal uridylyltransferase (tutase), rna ligase and grna-mrna chimera-forming activities. these experiments suggest that two distinct editing complexes exist. ... | 1992 | 1330537 |
| cloning and characterization of the gene encoding trypanosoma cruzi dna topoisomerase ii. | the gene encoding trypanosoma cruzi type ii topoisomerase (tctop2) was isolated from a genomic library with a heterologous probe corresponding to part of the trypanosoma brucei type ii topoisomerase (tbrtop2) gene. nucleotide sequencing of tctop2 showed that the gene consists of an open reading frame of 3696 nucleotides (1232 amino acids), predicting a polypeptide product of 138,413 da. comparison of the amino acid sequence with that of type ii topoisomerases from t. brucei (tbrtop2) and crithid ... | 1992 | 1331785 |
| allelic polymorphism of the trypanosoma brucei polyubiquitin gene. | we have characterized a second t. brucei polyubiquitin gene (ubb) that is highly similar in the coding and flanking regions to a previously described t. brucei polyubiquitin gene (uba). however, ubb differs from uba in 2 respects: (1) the predicted carboxy-terminal amino acid of ubb is methionine, as opposed to leucine in uba, and (2) ubb contains approximately 13 ubiquitin repeats, as opposed to approximately 30 repeats in uba. in southern blots of intact t. brucei dna separated by pulsed field ... | 1992 | 1331786 |
| characterization of sequence changes in kinetoplast dna maxicircles of drug-resistant leishmania. | we have compared kinetoplast dna maxicircles of tunicamycin- and arsenite-resistant variants of repeatedly cloned leishmania mexicana amazonensis showing dna amplification with wild-type and arsenite-resistant variants of the same lineage that do not show dna amplification. dna restriction patterns and the degree of cross-hybridization between maxicircle dna fragments of parasites displaying dna amplification and those of parasites without amplification were examined. in addition, the nucleotide ... | 1992 | 1336569 |
| the nucleotide sequence of the variable region in trypanosoma brucei completes the sequence analysis of the maxicircle component of mitochondrial kinetoplast dna. | the nucleotide sequence of two non-contiguous dna fragments of 4.0 and 2.2 kb, respectively, of the kinetoplast maxicircle of trypanosoma brucei brucei eatro strain 427 has been determined, completing the sequence analysis of the so-called variable region (see also de vries et al., 1988, mol. biochem. parasitol. 27, 71-82). analysis of the entire 8-kb variable region sequence revealed the presence of a 5.2-kb cluster of imperfect, tandemly repeated sequences, flanked by dna of unique sequence. b ... | 1992 | 1336570 |
| parasitaemia and clinical manifestations in trypanosoma brucei infected dogs. | four dogs were infected with trypanosoma brucei (mkar strain) while another four were used as uninfected controls. two of the dogs showed acute disease and died in the first wave of parasitaemia on days 7 and 8 post infection (pi) while the other two died from the sub-acute disease on days 24 and 28 pi corresponding to the second wave of parasitaemia. in the first wave of parasitaemia there was a sharp decrease in the packed cell volume, red blood cell, haemoglobin, total leucocytes, eosinophil, ... | 1992 | 1339994 |
| erythrocyte response to trypanosoma brucei in experimentally infected dogs. | trypanosoma brucei infection produced an acute and fatal disease in nigerian mongrel dogs due to a rapidly developing anaemia. infected dogs responded with increased reticulocytosis, which was not sustained with chronicity. in comparison the response to artificially-induced haemolytic anaemia was progressive, marked and sustained. the anaemia of t. brucei infection of dogs was either normocytic normochromic in acute infection or microcytic normochromic in chronic infection. artificially-induced ... | 1992 | 1339995 |
| some plasma biochemical changes in experimental trypanosoma brucei infection of sokoto red goats. | plasma biochemical changes were studied for 8 consecutive weeks in sokoto red goats experimentally infected by intravenous route injection of 1.6 x 10(7) trypanosoma brucei. the strain 8/18 was highly infective. the mean packed cell volume significantly decreased from 1 to 8 weeks post-infection (pi) at p < 0.05. during this period, the mean plasma total bilirubin concentrations significantly increased (p < 0.05). the mean plasma direct and indirect bilirubin concentrations significantly increas ... | 1992 | 1339997 |
| trypanosomatidae codon usage and gc distribution. | a study of trypanosomatidae gc distribution and codon usage is presented. the codon usage patterns in coincidence with the phylogenetical data are similar in crithidia and leishmania, whereas they are more divergent in trypanosoma brucei and t. cruzi. the analysis of the gc mutational pressure in these organisms reveals that t. brucei, and to a lesser extent t. cruzi, have evolved towards a more balanced use of all bases, whereas leishmania and crithidia retain features of a primeval genetic app ... | 1992 | 1343666 |
| a novel microtubule-binding motif identified in a high molecular weight microtubule-associated protein from trypanosoma brucei. | the major component of the cytoskeleton of the parasitic hemoflagellate trypanosoma brucei is a membrane skeleton which consists of a single layer of tightly spaced microtubules. this array encloses the entire cell body, and it is apposed to, and connected with, the overlying cell membrane. the microtubules of this array contain numerous microtubule-associated proteins. prominent among those is a family of high molecular weight, repetitive proteins which consist to a large extent of tandemly arr ... | 1992 | 1348252 |
| subcurative chemotherapy and fatal post-treatment reactive encephalopathies in african trypanosomiasis. | the treatment of late-stage african sleeping sickness in man is often complicated by a post-treatment reactive encephalopathy. the bases of this pathological reaction was investigated in a mouse model of african trypanosomiasis. subcurative treatment with diminazene aceturate, which did not clear parasites from the central nervous system, resulted in a post-treatment meningoencephalitis similar to that seen in man. by contrast, a curative regimen of melaminylthioarsenite and 5-nitroimidazole, wh ... | 1992 | 1348799 |
| trisomy and chromosome size changes in hybrid trypanosomes from a genetic cross between trypanosoma brucei rhodesiense and t. b. brucei. | further analysis of hybrid clones from an experimental cross of trypanosoma brucei rhodesiense 058 and t. b. brucei 196 shows 2 of the hybrid clones to have dna contents about 1.5 times parental values. this represents over 40,000 kb of extra dna. comparison of the molecular karyotypes of parental and progeny trypanosomes shows that the bulk of the extra dna constitutes chromosomes greater than 1 mb in size, although a small proportion can be accounted for by an increased number of mini-chromoso ... | 1992 | 1349422 |
| mass spectrometry of mrna cap 4 from trypanosomatids reveals two novel nucleosides. | synthesis of mrna in kinetoplastid protozoa involves the process of trans-splicing, in which an identical 39-41-nucleotide (depending on the species) mini-exon is placed at the 5' end of mature mrnas. the mini-exon sequence is highly conserved among all members of the kinetoplastida, nucleotides 1-6 being identical in the four genera so far examined. prior to trans-splicing, the mini-exon donor rna is capped by the addition of a (5'-5') triphosphate-linked 7-methylguanosine, followed by modifica ... | 1992 | 1349605 |
| method for analysis, and distribution profile, of covalently-linked ferritin-daunorubicin conjugate in the blood of trypanosome-infected mice. | daunorubicin is a highly potent trypanocide in-vitro but is inactive in-vivo. when daunorubicin is conjugated to bovine serum albumin or horse spleen ferritin using schiffs base linkages, the complex is trypanocidal in-vitro and in-vivo. we have developed novel analytical methods, using hplc with fluorimetric detection, for the quantitation of daunorubicin and doxorubicin in biological samples, either as unconjugated drug, or when covalently linked to macromolecules or particles. ferritin-daunor ... | 1992 | 1350628 |
| transcript-specific developmental regulation of polyadenylation in trypanosoma brucei mitochondria. | transcripts from many mitochondrial genes in kinetoplastids are heterogeneous in size, often occurring as 2 distinct size classes, but this cannot be accounted for by rna editing alone. analyses of transcripts from 6 mitochondrial genes of trypanosoma brucei indicates that the size variation is due to poly(a) tail length. a larger fraction of cyb, coi and coii transcripts have longer poly(a) tails in procyclic than in bloodstream forms. these transcripts are also more abundant in the procyclic f ... | 1992 | 1352374 |
| persistence of antibodies to trypanosoma brucei gambiense after treatment of human trypanosomiasis in uganda. | | 1992 | 1353180 |
| african trypanosomiasis: more aggressive treatment or more aggressive research? | | 1992 | 1353181 |
| the in vitro efficacy of reuterin on the culture and bloodstream forms of trypanosoma brucei brucei. | 1. the in vitro effects of a new antibiotic, reuterin, were determined for culture and bloodstream forms of trypanosoma brucei brucei. it inhibited growth of the culture forms and motility, viability and dna and protein syntheses of culture and bloodstream forms. 2. reuterin administered with inhibitors of ribonucleotide reductase (hydroxyurea and deoxyadenosine) was synergistic only for growth of the culture form of the parasite. 3. reuterin was trypanocidal at lower doses than dfmo, mel b, and ... | 1992 | 1354096 |
| absence of the litat 1.3 (catt antigen) gene in trypanosoma brucei gambiense stocks from cameroon. | antibodies to the variable antigen type (vat) designated litat 1.3 are common in sera from parasitologically confirmed patients with gambian sleeping sickness. for this reason, litat 1.3 has been considered a suitable antigen for detecting trypanosoma brucei gambiense in the card agglutination test for trypanosomiasis (catt; testryp-catt, smith kline-rit). however, surveys in the t.b. gambiense endemic focus of fontem in cameroon have suggested that expression of litat 1.3 might be rare or absen ... | 1992 | 1354930 |
| efficacy and toxicity of eflornithine for treatment of trypanosoma brucei gambiense sleeping sickness. | the usual first-line treatment for trypanosoma brucei gambiense sleeping sickness is melarsoprol, but when that fails the outlook has hitherto been grim. the polyamine synthesis inhibitor eflornithine (difluoromethylornithine, dfmo) has emerged as an alternative therapy. 207 patients with late-stage t b gambiense sleeping sickness were treated in rural zaire with three different regimens of dfmo in an open-trial design. during treatment, trypanosomes disappeared from the csf of all 87 patients i ... | 1992 | 1355219 |
| sequential infection of tsetse flies with trypanosoma congolense and trypanosoma brucei. | the question whether tsetse flies can be experimentally infected with more than one trypanosome species or strain by sequential feeding was investigated using dna probe technology to identify directly the small numbers of trypanosomes in the fly gut. bloodstream form trypanosomes of trypanosoma congolense or t. brucei ssp. were used for initial infection, followed by sequential feeds using either t. congolense or t. brucei ssp. midgut trypanosome populations were subsequently analysed by hybridi ... | 1992 | 1356306 |
| influence of d(+)-glucosamine on infection rates and parasite loads in tsetse flies (glossina spp.) infected with trypanosoma brucei. | teneral glossina morsitans centralis, g. m. morsitans and g. pallidipes were infected with three different clones of trypanosoma brucei in blood containing d(+)-glucosamine, an inhibitor of tsetse midgut lectin. on average, 5 days of d(+)-glucosamine treatment tripled infection rates, without affecting the proportion of infections that matured. total infection rates were equal in males and females, but twice as many infections matured in males. counts of parasites in the guts and salivary glands ... | 1992 | 1359749 |
| vector competence of glossina pallidipes and g. morsitans centralis for trypanosoma vivax, t. congolense and t. b. brucei. | vector competence of glossina pallidipes for pathogenic trypanosoma species was compared to that of g. morsitans centralis. cattle or goats were the hosts used to infect teneral tsetse, rabbits were used to maintain tsetse which were dissected on day 30. mean infection rates of g. pallidipes and g. m. centralis by t. vivax isolated from a cow in kenya were respectively 39.5 +/- 8.9% and 32.1 +/- 10.3% whilst for t. vivax isolated from a cow in nigeria, they were 30.0 +/- 7.5% and 19.8 +/- 4.3%. ... | 1992 | 1359753 |
| structural differences between the chromatin of procyclic trypanosoma brucei brucei and of higher eukaryotes as probed by immobilized trypsin. | soluble chromatin of trypanosoma brucei brucei procyclic culture forms was submitted to digestion with free or immobilized trypsin. digestion with trypsin in salt solutions of low and high ionic strengths generated characteristic sets of limit histone peptides. after incubation of chromatin with immobilized trypsin in a solution of low ionic strength, histones were not degraded, whereas a selective proteolysis occurred at 50 mm nacl. histones a and d, which correspond to h3 and h4 of higher euka ... | 1992 | 1359762 |
| application of a monoclonal antibody-based antigen detection enzyme-linked immunosorbent assay (antigen elisa) for field diagnosis of bovine trypanosomiasis at nguruman, kenya. | a monoclonal antibody-based, enzyme immunoassay (antigen elisa) for the detection of species-specific invariant antigens of trypanosoma congolense, t. vivax or t. brucei in the serum of infected animals was evaluated as a means of diagnosis using bovine field sera from a trypanosomiasis endemic area, nguruman, kenya. circulating trypanosome antigens were detected in 126 (96.2%) of 131 serum samples from animals with parasitologically confirmed diagnosis: 74.8% were positive for antigens of two o ... | 1992 | 1360196 |
| neisserial surface variation: how and why? | neisseria gonorrhoeae exhibits striking variability in several of its surface components (pili, opa proteins and lipooligosaccharide) in vivo and in vitro. such flagrant variation of this mucosal pathogen's surface components contrasts sharply with changes in single surface components of blood-borne trypanosomes and borreliae. despite these differences, similar molecular events are sometimes involved. | 1992 | 1360853 |
| glycosyl phosphatidylinositol-specific phospholipase c of trypanosoma brucei: expression in escherichia coli. | glycosyl phosphatidylinositol-specific phospholipase c (gpi-plc) from trypanosoma brucei cleaves the glycosyl phosphatidylinositol (gpi) anchor of the trypanosome variant surface glycoprotein (vsg) and other gpi structures. we have expressed this enzyme in escherichia coli, using a protocol designed to produce the native enzyme rather than a fusion protein. we have purified large amounts of gpi-plc from e. coli membranes, using a single step immunoaffinity technique. the expressed enzyme is iden ... | 1992 | 1362451 |
| evolution of the retrotransposons trs/ingi and of the tubulin genes in trypanosomes. | the african trypanosomes have genomes of high plasticity, as demonstrated for instance by their ability to shuffle their genes around, coding for variant-specific surface glycoproteins (vsgs). another indication of their genome plasticity is the presence of multiple retro-elements. the retrotransposon-like element trs/ingi is present in many copies in the genome of trypanosomes. one particular derivative of trs/ingi, called tubis, had previously been found to interrupt a tubulin gene in a partic ... | 1992 | 1363182 |
| some kinetic properties of pyruvate kinase from trypanosoma brucei. | we have studied the kinetics of the allosteric interactions of pyruvate kinase from trypanosoma brucei. the kinetics for phosphoenolpyruvate depended strongly on the nature of the bivalent metal ions. pyruvate kinase activated by mg2+ had the highest catalytic activity, but also the highest s0.5 for phosphoenolpyruvate, while the opposite was true for pyruvate kinase activated by mn2+. the reaction rates of mg(2+)-pyruvate kinase and mn(2+)-pyruvate kinase were clearly allosteric with respect to ... | 1992 | 1371328 |
| the parp and vsg genes of trypanosoma brucei do not resemble rna polymerase ii transcription units in sensitivity to sarkosyl in nuclear run-on assays. | addition of the ionic detergent n-lauroylsarcosine (sarkosyl) affects the efficiency of transcription of genes of the protozoan trypanosoma brucei in nuclear run-on assays. transcription of the parp (procyclin or procyclic acidic repetitive protein), variant cell surface glycoprotein (vsg) and ribosomal rna (rrna) genes was resistant or increased after addition of sarkosyl. in contrast, the transcription of seven protein coding house keeping genes and the mini-exon donor rna (medrna) genes was c ... | 1992 | 1371345 |
| developmental variation of glycosylphosphatidylinositol membrane anchors in trypanosoma brucei. in vitro biosynthesis of intermediates in the construction of the gpi anchor of the major procyclic surface glycoprotein. | the african trypanosome, trypanosoma brucei, expresses two abundant stage-specific glycosylphosphatidylinositol (gpi)-anchored glycoproteins, the procyclic acidic repetitive protein (parp or procyclin) in the procyclic form, and the variant surface glycoprotein (vsg) in the mammalian bloodstream form. the gpi anchor of vsg can be readily cleaved by phosphatidylinositol (pi)-specific phospholipase c (pi-plc), whereas that of parp cannot, due to the presence of a fatty acid esterified to the inosi ... | 1992 | 1371998 |
| molecular biology of african trypanosomes: development of new strategies to combat an old disease. | african trypanosomes are protozoan parasites that cause a number of diseases of man and domesticated animals in large regions of sub-saharan africa. the diseases have proven to be particularly difficult to prevent or to effectively treat due to features of both the trypanosome and the insect vector, the tsetse fly. the habitat of the tsetse and its resistance to insecticides have rendered vector control efforts ineffective. attempts to develop a vaccine against the african trypanosomes has been ... | 1992 | 1373267 |
| variable and conserved structural elements of trypanosome variant surface glycoproteins. | the characterization of b cell epitopes on the trypanosome variant surface glycoprotein (vsg) rests on elucidation of variant specific amino acid sequences that may be exposed or buried as a result of the natural conformation of these molecules in the surface coat. despite the fact that different vsgs have heterogeneous primary sequences and unique antigenic characteristics, recent high resolution x-ray crystallographic analyses of vsgs have revealed a conserved 3-dimensional structure common to ... | 1992 | 1373472 |
| guide rnas for transcripts with developmentally regulated rna editing are present in both life cycle stages of trypanosoma brucei. | rna editing of several mitochondrial transcripts in trypanosoma brucei is developmentally regulated. the cytochrome b and cytochrome oxidase ii mrnas are edited in procyclic-form parasites but are primarily unedited in bloodstream forms. the latter forms lack the mitochondrial respiratory system present in procyclic forms. editing of the nadh dehydrogenase 7 (nd7) and nd8 transcripts is also developmentally regulated but occurs preferentially in bloodstream forms. other transcripts, cytochrome o ... | 1992 | 1373804 |
| maxicircle cr1 transcripts of trypanosoma brucei are edited and developmentally regulated and encode a putative iron-sulfur protein homologous to an nadh dehydrogenase subunit. | the maxicircle of trypanosoma brucei encodes components of the mitochondrial oxidative phosphorylation system, as do other mitochondrial dnas, but maxicircle gene identification is complicated by extensive editing of some transcripts. we found that transcripts from the cr1 region were extensively edited, as are other transcripts from maxicircle regions which exhibit strong g versus c strand bias. editing added 259 uridines and removed 46 uridines to produce an approximately 574-nucleotide mature ... | 1992 | 1373807 |
| in vitro guide rna/mrna chimaera formation in trypanosoma brucei rna editing. | the post-transcriptional processing of various mitochondrial transcripts in kinetoplastids, krna editing, adds and removes uridines, producing mature messenger rnas. this editing seems to be directed by 'guide' rnas (grnas) which are complementary to portions of the mature message. the editing mechanism has been proposed to entail transesterification. detection of chimaeric grna-mrna molecules, intermediates predicted by transesterification, support this model. we report here the in vitro format ... | 1992 | 1374163 |
| in vivo assessment of drug sensitivity of african trypanosomes using the akinetoplastic induction test. | following treatment of mice infected with trypanosoma congolense or t brucei brucei with various doses of isometamidium chloride or diminazene aceturate, the induction of akinetoplastic (ak) forms was observed in the trypomastigotes of both species within 10 hours of drug administration. the levels of ak-induction were closely correlated with the levels of resistance to each compound found using a standard in vivo drug assay in mice. in general, ineffective doses of either compound conferred ak- ... | 1992 | 1374928 |