Publications

the kinetoplast dna of trypanosoma equiperdum.	we have analyzed the kinetoplast dna for trypanosoma equiperdum (american type culture collection 30019) and two dyskinetoplastic strains derived from it. the dna networks from the kinetoplastic strain are made up of catenated mini-circles and maxi-circles, like the networks from the closely-related trypanosoma brucei. the mini-circles of t. equiperdum lack the pronounced sequence heterogeneity of t. brucei mini-circles, as shown by the fragment distribution of restriction digests and by the pre ...	1980	6249368
movable genes.		1980	6253793
evidence for a branched electron transport chain in trypanosoma brucei.	the flow of electrons the terminal oxidases present in the bloodstream and procyclic trypomastigotes of trypanosoma brucei lump 1026 has been investigated by the use of salicylhydroxamic acid (sham) and cyanide. respiration in bloodstream trypomastigotes was completely inhibited by 0.5 mm sham with a ki below 10 microm. the ki for sham in procyclic trypomastigotes was 70 microm. in procyclic trypomastigotes there are at least three terminal oxidases of which the two major ones are cytochrome aa3 ...	1980	6255326
'swell dialysis' demonstrates that adenylate cyclase in trypanosoma brucei is regulated by calcium ions.	a new technique, 'swell dialysis', is described that allows the study of cellular enzymes in situ if they are located in the cytoplasm or on the cytoplasmic face of any membrane. the technique is potentially applicable to any population of individual eukaryotic cells that lack a cell wall. in this study swell dialysis has been applied to an examination of the regulation of adenylate cyclase in blood-stream forms of trypanosoma brucei (427-12/ici-060). adenylate cyclase in this protozoon is shown ...	1980	6257514
studies on glycerol kinase and its role in atp synthesis in trypanosoma brucei.	glycerol kinase of trypanosoma brucei has been shown to be capable of catalysing sn-glycerol-3-phosphate dependent adp phosphorylation for atp generation. the rate of this reaction (vr) is sufficient to account for the observed rate of glycerol production from anaerobic glucose metabolism by intact cells and to account for net atp synthesis. glycerol kinase has been purified by preparing a post-nuclear, particulate fraction and solubilizing the enzyme with 0.5% (w/v) triton x-100. this treatment ...	1980	6258071
cloning and characterization of dna sequences complementary to messenger ribonucleic acids coding for the synthesis of two surface antigens of trypanosoma brucei.	full length double-stranded complementary dnas (ds cdnas) could be synthesized on mrnas enriched in sequences coding for the synthesis of the variant specific antigens (vsas) antat 1.1 and antat 1.8 from trypanosoma brucei brucei. the size of these ds cdnas is about 1700 and 1850 base pairs for antat 1.1 and antat 1.8 respectively. the ds cdnas were cloned in the plasmid pbr322; two clones harboring a copy of each coding sequence were selected. both the hybrid-arrested translation and the positi ...	1980	6258157
variations in maxi-circle and mini-circle sequences in kinetoplast dnas from different trypanosoma brucei strains.	we have compared a total of 30 recognition sites for eight restriction endonucleases on the 20-kilobase-pair maxi-circle of kinetoplast dnas from five different trypanosoma brucei strains. in addition to three polymorphic sites were have found a 5 kilobase-pair region that is not cleaved by any of the eight enzymes and that varies in size over 1 kilobase pair in the strains analysed. mini-circles from these five strains, digested with endonuclease taqi or mboii, yield very complex fragment patte ...	1980	6260147
analytical techniques for cell fractions. xxviii. dissection of complex antigenic mixtures using monoclonal antibodies and two-dimensional gel electrophoresis.		1980	6153870
in vitro cloning of animal-infective bloodstream forms of trypanosoma brucei.	clones of animal-infective bloodstream forms of trypanosoma brucei (stocks s.427 and lump 227) were made by transferring a single organism from bloodstream-form cultures into each well of microtest ii tissue culture plates containing bovine fibroblast-like feeder cells. when the number of trypanosomes increased to 10(2)--10(3)/well on days 4--16, they were transferred into plastic t-25 culture flasks also containing feeder cells and fresh medium. cultures were thereafter maintained by partially ...	1980	6154276
characterization of trypanosoma brucei isolated from lymph nodes of rats.	forms of trypanosoma brucei isolated from lymph nodes of cyclically or intravenously infected rats, at different stages of infection, were morphologically compared with the corresponding bloodstream forms. unlike the pleomorphic bloodstream trypanosome population, the lymph node trypanosome population was essentially monomorphic and resembled the slender forms of the bloodstream. values for the morphometric parameters indicated a position between the slender and the stumpy forms. the number of t ...	1980	6154277
trypanosoma brucei: radioimmunoassay of variant surface glycoproteins from organisms grown in vitro and in vivo.		1980	6157559
the kinetoplast dna of the hemoflagellate protozoa.	the kinetoplast dna of leishmania tarentolae and trypanosoma brucei was studied in terms of genetic organization and transcriptional activity. several minor sequence classes of minicircles from l. tarentolae were cloned in a bacterial plasmid and were compared in terms of sequence organization. the cloned minicircles were characterized by the possession of a constant region of at least 91 nucleotides and a variable region. minicircles from trypanosoma brucei strain 366d were also cloned. fragmen ...	1980	6159799
murine t lymphocyte specificity for african trypanosomes. i. induction of a t lymphocyte-dependent proliferative response to trypanosoma brucei.	a procedure which results in the specific activation of primed murine t lymphocytes was adapted for the study of t lymphocyte activation by the african trypanosome: trypanosoma brucei. the assay calls for the in vivo priming of lymphocytes by the subcutaneous administration of parasites, followed by the co-cultivation in vitro of cells taken from the regional draining lymph nodes and the parasite. this co-cultivation results in a marked proliferation of lymphoid cells. the proliferation was show ...	1980	6160003
[behaviour of the trypanosoma brucei brucei strain stib 348c in mice. 1. influence of human serum on the strain (author's transl)].		1980	6160658
antigenic analysis by immunofluorescence of in vitro-produced metacyclics of trypanosoma brucei and their infections in mice.	the antigenic types in populations of metacyclic trypanosomes of trypanosoma brucei isolated from glossina morsitans head-salivary gland trypanosome cultures and bloodstream forms in the early parasitemias produced from whole culture supernatant fluids containing metacyclic forms, were analyzed by the indirect fluorescent antibody test using clone-specific antisera. metacyclic trypanosomes in cultures initiated with cloned bloodstream forms with heterogeneous with respect to their variable antig ...	1980	6161247
rheumatoid factors in mice: non-specific activators of heterophile rheumatoid factor production.	although possibly the best, lps is by no means the only non-specific activator of immune responsiveness (air). plant lectins such as pha and pwm have some ability to stimulate both total igm production (reverse igm pfc) and more particularly heterophile and homophile igm rheumatoid factor (rf) responses, together with igm 'antibody' responses to target antigens such as xenogeneic red blood cells or haptens such as tnp. some parasitic infections and/or parasite antigens were shown to be powerful ...	1980	6161873
kinetoplast dna and rna of trypanosoma brucei.	kinetoplast dna (kdna) and kinetoplast rna (krna) were isolated from bloodstream and procyclic culture forms of two clonal strains of trypanosoma brucei. no differences were observed in kdna (maxicircle) restriction profiles between bloodstream or procyclic culture forms of the same strain. some differences were observed in kdna maxicircle restriction sites between the two strains. buoyant density analysis of pst i digested kdna showed the release of a minor low density band representing unit le ...	1980	6162099
relationship between trypanosoma "brucei" and t. "rhodesiense".		1980	6163234
glycoproten biosynthesis in trypanosoma brucei. the glycosylation of glycoproteins located in and attached to the plasma membrane.	1. glycosyltransferase activity incorporating n-[14c]acetylglucosamine ([14c]glcnac) from uridine diphosphate n-[14c]acetylglucosamine (udp-[14c]glcnac) into endogenous proitein acceptors was localized primarily in the plasma membrane of trypanosoma brucei. 2. the acceptor site for the nucleotide sugar was further localized exclusively to the cytoplasmic face of the plasma membrane. 3. the glycosyltransferase produced elongation of the growing oligosaccharide chains while they were attached to t ...	1980	6447596
trypanosoma brucei: preparation and some properties of a multienzyme complex catalysing part of the glycolytic pathway.		1980	6447613
malate dehydrogenase in african trypanosomes--i. preliminary studies with t. brucei.		1980	6448757
glycolysis in trypanosoma brucei.	the possibility that the glycosomes present in the bloodstream form of trypanosoma brucei [opperdoes, f. r. and borst, p. (1977) febs lett. 80, 360--364] constitute a separate pool of glycolytic intermediates within the cell was investigated. in titrations of intact cells with digitonin, a differential activation of glycolytic enzymes was observed. enolase, pyruvate kinase and the cell-sap marker alanine aminotransferase were activated at 0.05 mg digitonin per mg protein. the nine glycosomal enz ...	1980	6766864
energized amino acid transport by trypanosoma brucei requires a glycolytic intermediate.		1980	6772490
polyamine metabolism: a potential therapeutic target in trypanosomes.	alpha-difluoromethylornithine (rmi 71,782), a specific irreversible inhibitor of the first step in polyamine biosynthesis, that is, the formation of putrescine from ornithine by ornithine decarboxylase, cures mice infected with a virulent, rodent-passaged strain of trypanosoma brucei brucei. this parasite is closely related to the trypanosomes that cause human sleeping sickness. the drug, which is remarkably nontoxic, was effective when administered in drinking water or by intubation. the abilit ...	1980	6775372
miconazole: an inhibitor of cyanide-insensitive respiration in trypanosoma brucei.		1980	6776666
isolation and characterization of polysomes from trypanosoma brucei.	the isolation of polysomes in bulk from bloodstream forms of trypanosoma brucei is described. the polysomes are active in in vitro protein synthesis in the presence or absence of initiation inhibitors. nascent variant surface antigen (vsa) has been detected on these polysomes using purified radio-iodinated antibody. edta-induced ribosomal sub-units and their large rrna's are characterized. the 26s rrna is nicked to produce 2 molecules which are both smaller than the 19s rrna of the small sub-uni ...	1980	6785709
the segregation of kinetoplast dna networks in trypanosoma brucei.		1980	6927767
trypanosoma brucei brucei: inhibition of glycosylation of the major variable surface coat glycoprotein by tunicamycin.	trypanosoma brucei brucei incorporates d-[3h]mannose into protein in vitro in a medium we describe here. the label appears entirely in glycoproteins with approximately 90% in the major variable surface coat glycoprotein (vscg). incorporation is linear for 60 min and usually continues for an additional 30 min although at a decreased rate. in the same medium incorporation of l-[14c]serine is linear for 90 min. incorporation of [3h]mannose is completely inhibited by tunicamycin at concentrations ab ...	1980	6929505
sequences of two kinetoplast dna minicircles of tryptanosoma brucei.	kinetoplast dna of trypanosoma brucei is composed of a network of about 10,000 interlocked minicircle dna molecules (1.0 kilobase) that are catenated with about 50 maxicircle dna molecules (23 kilobases). several different dna . dna hybridization techniques using individual minicircle dna sequences cloned in escherichia coli have indicated that each minicircle molecule contains about one-fourth of its sequence in common with most other minicircles and the remaining three-fourths in common with a ...	1980	6930643
a model for cardiopathy induced by trypanosoma brucei brucei in mice. a histologic and immunopathologic study.	the successful induction of pancarditis in mice by the use of trypanosoma brucei brucei is reported. the sequential analysis of whole-organ sections demonstrated the presence of trypanosomes in the cardiac structures from the fourth week after infection. parasites predominated on the endocardial and epicardial side but were also present in the valves, the conducting system, and the lymphatic system draining the heart, the latter being particularly evident in late infection. at the time of parasi ...	1980	6990771
application of morphometry to pathogenic trypanosomes (protozoa, mastigophora).		1980	6994074
trypanosoma brucei brucei: a model for cerebral trypanosomiasis in mice--an immunological, histological and electronmicroscopic study.	the successful induction of cerebral trypanosomiasis in ordinary laboratory mice using trypanosoma brucei brucei is reported. sequential studies demonstrated the presence of trypanosomes in the interstitium of the choroid plexus at the fourth week after infection which correlated with the appearance of anti-trypanosomal antibodies, a rise of igm and igg serum levels and a rise of clq binding activity as well as a decrease of c3 levels. electronmicroscopic studies showed that the parasites were f ...	1980	6998617
trypanosoma: intricacies of biochemistry, morphology and environment.		1980	6998787
pyrazolopyrimidine metabolism in african trypanosomes: metabolic similarities to trypanosoma cruzi and leishmania spp.	growth inhibition and radioisotope incorporation studies with allopurinol (4-hydroxypyrazolo(3,4-d)pyrimidine) have shown that the african trypanosomes are biologically and biochemically similar to leishmania spp. and trypanosoma cruzi with respect to their response to this compound. these organisms, as a group, share the unique ability to convert allopurinol sequentially to its ribonucleoside monophosphate and 4-aminopyrazolo(3,4-d)pyrimidine ribonucleoside mono-, di- and triphosphates.	1980	7003380
isolation of trypanosoma brucei variant specific antigen mrna by immunoprecipitation of polysomes.	the mrna encoding the variant specific antigen of trypanosoma brucei has been prepared by immunoprecipitation of polysomes. polysomes carrying the variant specific antigen account for approx. 3% of the total polysomes. the mrna thus produced is active in the mrna dependent rabbit reticulocyte lysate in vitro protein synthesis system and directs the synthesis of a polypeptide of 60 000 daltons which co-migrates both with 125i-labelled purified variant specific antigen and with antigen immunopreci ...	1980	7003381
cloning and expression of trypanosoma brucei kinetoplast dna in escherichia coli.	the kinetoplast dna of trypanosoma brucei is made of two components: mini-circles (1 kb, 90% of total kdna) and maxi-circles (20 kb, 10%) of total kdna). these are interlocked to form a network of about 10 000 kb. in order to analyse the components of such a network structure, we have cloned individual mini-circle molecules and two of the three ecori maxi-circle fragments in e. coli. cloned mini-circles are somewhat heterogeneous in size and their restriction patterns are completely different. d ...	1980	7019010
an accidental laboratory infection with african trypanosomes of a defined stock. i. the clinical course of the infection.		1980	7185919
an accidental laboratory infection with trypanosomes of a defined stock. ii. studies on the serological response of the patient and the identity of the infecting organism.		1980	7185920
[prophylactic and curative action of ridzol-s and ronidazole in experimental trypanosomiasis caused by trypanosoma brucei et t. evansi].		1980	7195691
trypanotolerance in inbred mice: an immunological basis for variation in susceptibility to infection with trypanosoma brucei.	previous studies have suggested that the suppression of igm responses induced by different strains of trypanosomes can be related to the virulence of the parasite in a defined mouse strain (sacks et al. 1980). this study has examined immunosuppression induced by trypanosoma brucei nim7 in two mouse strains (c3h/he and [cba/h x c57b1/6]f1) which differ considerably in their ability to survive infections. the results confirm our previous studies in that mice were able to survive infection whilst t ...	1980	7233540
accumulation of phospholipase a1 in tissue fluid of rabbits infected with trypanosoma brucei.	samples of tissue fluid were obtained from plastic cages implanted subcutaneously in rabbits. a phospholipase a1 similar to that found in trypanosoma brucei appeared in the tissue fluid about seven days after infection with this parasite, increasing with parasite burden, and reaching levels of more than 5 nmol phosphatidylcholine hydrolysed per min per ml tissue fluid. the large amount of phospholipase a1 found free in the tissue fluid appeared to be of trypanosomal origin and was either secrete ...	1980	7233541
intrinsic immunosuppressive activity of different trypanosome strains varies with parasite virulence.		1980	7352025
a comparison of the melting characteristics and base composition of deoxyribonucleic acid from trypanosoma brucei and trypanosoma vivax.		1980	7353716
experimental trypanosoma brucei infection in deer mice: splenic changes.	forty deer mice (peromyscus maniculatus) were infected with trypanosoma brucei organisms and were killed 33 to 83 days after inoculation (average, 63). the outstanding lesion was infiltration of plasma cells in various tissues. these cells caused disruption of the periarteriolar lymphocytic sheaths and thickening of red pulp cords in the spleen. the lymph node was almost completely replaced by plasma cells. the spleen and lymph nodes also had marked hyperplasia of germinal centers and granulomat ...	1980	7361379
the isolation of plasmids containing dna complementary to messenger rna for variant surface glycoproteins of trypanosoma brucei.	we have isolated poly(a)+ rna from four antigenic variants (117, 118, 121, 221) of one clone of trypanosoma brucei. translation of these poly(a)+ rnas in a rabbit reticulocyte lysate gave rise to proteins that could be precipitated with antisera against homologous variant surface glycoprotein, the protein responsible for antigenic variation in trypanosomes. from the electrophoretic mobility of these in vitro products in sodium dodecyl sulphate (sds) gels we infer that variant surface glycoprotei ...	1980	7364218
dna polymerases in parasitic protozoans differ from host enzymes.	analysis of extracts of the bloodstream forms of trypanosoma brucei showed that both dna polymerase-alpha and dna polymerase-beta activities were present. the detection of dna polymerase-beta in t. brucei demonstrates the presence of this enzyme in unicellular organisms. dna polymerase-beta is present also in leishmania mexicana. the dna polymerases in t. brucei are immunologically distinct from the host enzymes. the structural differences between the parasite and the host enzymes could be explo ...	1980	7367875
trypanosoma brucei: maintenance of concentrated suspensions of bloodstream trypomastigotes in vitro using continuous dialysis for measurement of endocytosis.		1980	7371738
'berenil' and nitroimidazole combinations in the treatment of trypanosoma brucei infection with central nervous system involvement.		1980	7372389
hydroxyurea: effect on growth, structure, and [3h]thymidine uptake of trypanosoma brucei procyclic culture forms.	hydroxyurea (hu) in concentrations above 50 micrograms/ml reversibly inhibited cell division of trypanosoma brucei brucei stock stib 336 procyclic culture forms, but not growth of individual cells. the volume of the nucleus and of the cytoplasm increased in the presence of the drug as did the percentage of cells with 2 kinetoplasts. electron microscopy revealed that the nuclear membrane was extended forming protrusions which surrounded areas of the cytoplasm. replication of the kinetoplast dna d ...	1980	7373568
studies on the anaemia in rabbits infected with trypanosoma brucei brucei. 1. evidence for haemolysis.		1980	7391273
studies on the anaemia in rabbits infected with trypanosoma brucei brucei. 2. haematological studies on the role of the spleen.		1980	7391275
chromatographic resolution of two dna polymerase activities from bloodstream forms of trypanosoma brucei: differential responses to exogenous polyamine addition.		1980	7396895
a study of the effects of some game animal tranquillising drugs on trypanosoma brucei rhodesiense infections in white rats.		1980	7398548
murine trypanosomiasis: cellular proliferation and functional depletion in the blood, peritoneum, and spleen related to changes in bone marrow stem cells.	previous reports have described profound effects on the function of the lymphoid system, especially the spleen, in mice infected with trypanosoma brucei. this study provides further evidence of major change in the cell populations of the blood, peritoneum, and bone marrow, but shows that at least some of the stem cells of the bone marrow survive the damage caused by trypanosomes and retain their ability to repopulate the animal. in these infected mice the initial parasitemia was terminated by da ...	1980	7399696
the separation and structure of infective trypanosomes from cultures of trypanosomas brucei grown in association with tsetse fly salivary glands.	infective trypanosomes developed when trypanosoma brucei was cultivated at 28 c in a liquid medium containing tsetse fly head-salivary gland explants. they were separated from the noninfective culture forms using deae-cellulose column chromatography. it was demonstrated by light and electron microscopy that the separated organisms were morphologically similar to metacyclic stages found in a tsetse fly and that they had a characteristic surface coat. single metacyclic trypanosomes isolated from t ...	1980	7400995
[ultrastructural alterations, infectivity, and motility of trypanosoma brucei before and after cryopreservation in liquid nitrogen (author's transl)].		1980	7415415
[a comparative study of the morphology of the trypanosoma brucei brucei trypomastigote using photonic microscopy and scanning electron microscopy (author's transl)].		1980	7416690
initiation of trypanosome transformation from bloodstream trypomastigotes to procyclic trypomastigotes.		1980	7420248
evidence for diploidy and mating in trypanosomes.	the question of whether any sexual process takes place at some stage of the life cycle of the trypanosome has often been raised and crosses between different drug-resistant strains have provided no convincing answer. multinucleate forms of trypanosomes have been observed by electron microscopy but their significance and origin remain obscure. as part of a study aimed at examining the speciation and genetics of the trypanosoma brucei complex of trypanosomes, a series of isolates from a population ...	1980	7422004
immunological clearance of 75se-labelled trypanosoma brucei in mice. ii. mechanisms in immune animals.	using trypanosomes labelled with [75se]-methionine a series of experiments was conducted to investigate the respective roles of antibody, macrophage activtion and complement in the removal of trypanosomes from the circulation of immune mice. it was found that clearance in such animals is largely accomplished by antibody-mediated hepatic phagocytosis, which, at least in passively immunized animals, is dependent on opsonization involving c3. no evidence was found to suggest that intravascular lysi ...	1980	7429544
preliminary observations on the infectivity of slender forms of trypanosoma brucei rhodesiense to glossina morsitans morsitans.		1980	7434409
use of antigens of cultured trypanosoma brucei in tests for bovine trypanosomiasis.	microelisa tests for the detection of trypanosomal antibodies in cattle infected with trypanosoma brucei, t. vivax and t. congolense were carried out using antigens prepared from culture forms and bloodstream forms of t. brucei. antigens prepared from culture forms gave similar microelisa values to those obtained with bloodstream form antigens and statistical analysis of the results obtained with both antigen preparations and sera from the infected animals showed significant high positive correl ...	1980	7434472
fine structure of metacyclic forms of trypanosoma brucei grown in continuous culture.	the fine structure of metacyclic forms of trypanosoma brucei propagated in vitro for about 300 days was studied. it was shown that the long and slender parasites possessed a surface coat over the plasma membrane and had many peroxisome-like bodies. the golgi complex was active and the rough endoplasmic reticulum was prominent. the short and stout parasites originally referred to as "intermediate type" lacked a surface coat, but their cytoplasm contained many lipid inclusions and few peroxisome-l ...	1980	7435784
an introduction to antigenic variation in trypanosomes.	the salivarian trypanosomes have a unique capacity for antigenic variation at the cell surface. this phenomenon is their primary mechanism for evasion of the host's immune response. variation is mediated through alternate expression of an extensive repertoire of variant surface glycoproteins (vsgs). extensive amino acid sequence diversity is responsible for the antigenic diversity of vsgs. all the isolated vsgs of trypanosoma brucei studied also contain an immunologically cross-reacting glycosyl ...	1980	7435800
the genes for variant antigens in trypanosomes.	we have studied the mechanism of antigenic variation by using dna complementary to the messenger rnas for four variant surface glycoproteins of trypanosoma brucei. pure complementary dnas were obtained by cloning as recombinant dna in escherichia coli. using these complementary dnas as hybridization probes, we have analyzed the genes for these variant surface glycoproteins. the results provide new information on the origin and evolution of antigenic variation, and on the mechanism involved in sw ...	1980	7435801
analyses of variable antigen gene rearrangements in trypanosoma brucei.	for the purpose of investigating the genetic basis of antigenic variation in trypanosoma brucei, we have analyzed the structure of the genome surrounding the gene coding for one t. brucei variable antigen (iltat 1.2) in several t. brucei clones expressing this and other variable antigens. in each case there are two copies of the gene. we found no evidence of an extra copy associated with the expression of this gene. differences were found between the two copies in a single clone, and between the ...	1980	7435802
structural analysis of variant and invariant genes in trypanosomes.	variant surface antigens have been purified from variants of a newly developed serodeme of trypanosoma brucei 164, and found to be distinct by immunological and molecular criteria. cdna clones containing variant and invariant gene sequences were isolated by using rna from different variants and cloned dnas from other systems as probes. these trypanosome and heterologous cloned dnas were used as probes of trypanosome gene structure and activity. regulation of variant antigen gene expression is at ...	1980	7435803
kinetoplast dna of normal and mutant trypanosoma brucei.	kinetoplast dna (kdna) sequence organization, transcription, and alterations in dyskinetoplastic (dk) mutants were examined in trypanosoma brucei, using physically isolated and recombinant kdna sequences. maxicircles renatured as a single sequence class and had no homology with minicircles. total minicircle complexity was greater than 300 kb. minicircle sequence organization is complex. different minicircles have sequences in common and comprise varying fractions of the kdna network. transcripts ...	1980	7435805
purification and characterization of pyruvate kinase from trypanosoma brucei.		1980	7436410
effect of storage in ice on pathogenicity of salivarian trypanosomes.		1980	7437543
6.5 s rna; preliminary characterisation of unusual small rnas in trypanosoma brucei.	in this paper we report the preliminary characterisation of some unusual small rrnas isolated from trypanosoma brucei. these molecules correspond closely in size and properties to the 5 s and 5.8 s rrnas of other eukaryotes and in addition there are two further small rnas which we designate 6.5 s rna. these have been characterised by sucrose gradient centrifugation and electrophoresis in denaturing gels. the two 6.5 s rnas may be distinguished from each other on the basis of their size and the d ...	1980	7442711
purification and cell-free translation of mrna coding for a variant specific antigen from trypanosoma brucei gambiense.	messenger rna (mrna) coding for a variant specific surface antigen (vsa) from trypanosoma brucei gambiense was isolated from total trypanosomal polyribosomes by indirect immunoprecipitation. an igg fraction of antisera to purified vsa was obtained by ion exchange chromatography and protein a-agarose affinity chromatography. these antibodies were then subjected to affinity chromatography on a vsa-agarose column to remove non-specific igg. polyribosomes from the same antigenic variant of t. b. gam ...	1980	7442715
fatty acid uptake by bloodstream forms of trypanosoma brucei and other species of the kinetoplastida.	1. trypanosoma brucei and other species of the kinetoplastida readily take up fatty acids from a simple incubation medium. this suggests that they at least partially satisfy their nutritional requirements for fatty acids from an exogenous source. 2. uptake of fatty acids in t. brucei follows a biphasic time course, consisting of an initial rapid phase, thought to represent surface binding, followed by a slower accumulation phase. 3. culture forms of t. brucei take up more than 10 times as much f ...	1980	7442716
trypanosoma brucei brucei: patterns of glycolysis at 37 degrees c in vitro.	in the absence of mammalian cells, freshly isolated monomorphic bloodstream forms of trypanosoma brucei brucei maintain a constant and high level of aerobic glycolysis in vitro for at least 4 h at 37 degrees c when suspended in rpmi medium 1640 containing 20% heat-inactivated and dialyzed fetal calf serum and 25 mm hepes at an initial ph of 8. in the absence of nutrients other than glucose, salts and protein, some cell death and a decrease in the rate of glycolysis are observed. in the absence o ...	1980	7442719
a variant surface glycoprotein of trypanosoma brucei synthesized with a c-terminal hydrophobic 'tail' absent from purified glycoprotein.	sequential expression of variant surface glycoproteins (vsgs) enables the parasitic protozoan trypanosoma brucei to evade the immune response of its mammalian hosts. studies of several vsgs, which have been isolated as soluble molecules following disruption of cells in the absence of detergent, have indicated extensive amino acid diversity and the absence of a hydrophobic segment which might serve to anchor the carboxy terminus to the membrane. the carboxy-terminal tryptic peptides of six vsgs h ...	1980	7442811
uptake of purine bases and nucleosides in african trypanosomes.	uptake of radioactivity labelled purine bases and nucleosides by suspensions of trypanosoma brucei and trypanosoma congolense in bicine buffer was determined at 37 degrees c. with t. brucei, the rate of uptake of adenosine was much greater than that of the other compounds tested, the uptake of which decreased in the order adenine, inosine, guanosine and hypoxanthine. with t. brucei, adenosine uptake increased with concentration in a manner suggesting two mechanisms, one with high and the other w ...	1980	7443300
trypanosome-induced suppression of anti-parasite responses during experimental african trypanosomiasis.	the effect of trypanosoma brucei infections on parasite-specific antibody responses was examined by immunization of infected mice with radio-attenuated trypanosomes of a noncross-reacting clone. antibody titers (total ig) against variant surface antigen were determined by indirect immunofluorescence. the suppression resulting from acute infection was virtually complete, and is associated with the failure to control the first relapse variant of the acute clone. the suppression resulting from chro ...	1980	7202480
trypanosoma brucei: detection of antigen deposits in glomeruli of mice vaccinated with purified variable antigen.		1980	7210115
immunopathological and chemotherapeutic studies in experimental trypanosomiasis with special reference to the heart and brain.		1980	7210124
cultivation of dyskinetoplastic trypanosoma brucei.		1980	7218102
role of glycerol permeation in the bloodstream form of trypanosoma brucei.	under aerobic conditions, we have determined glycerol uptake in the long slender (ls) bloodstream form of trypanosoma (trypanozoon) brucei brucei by studying glycerophosphate accumulation in the parasites. the coupled enzyme theory applies to the permeation-phosphorylation sequence. glycerol passage through the plasma membrane is asymmetric, the efflux process being favored over the influx process. no free diffusion of glycerol can be detected even under conditions under which free glycerol accu ...	1980	7218186
sequence heterogeneity in kinetoplast dna: reassociation kinetics.		1980	7335823
[metabolic adaptation between the host and the parasite].		1980	7344321
hypertriglyceridemia associated with trypanosoma brucei brucei infection in rabbits: role of defective triglyceride removal.	rabbits infected with trypanosoma brucei brucei develop a hypertriglyceridemia characterized by an increase in very low density lipoprotein and, to a lesser extent, low density lipoprotein, with a decrease in high density lipoprotein. triglyceride production studies showed that the triglyceride production rate was not significantly different in trypanosome-infected rabbits from controls. studies of triglyceride degradation using very low density lipoprotein triglyceride endogenously labelled wit ...	1980	7464858
carbohydrate alters the trypanocidal activity of normal human serum with trypanosoma brucei.	three categories of carbohydrates are distinguished based on their effects on the trypanocidal activity of normal human serum on trypanosoma brucei. the first category includes carbohydrates such as glucose, mannose and fructose which are utilized by parasites as an energy source. these carbohydrates inhibit the trypanocidal activity in a concentration-dependent manner. the third category, represented by xylose and mannitol, are not energy sources to the parasites but inhibit the trypanocidal ac ...	1980	7464859
trypanosoma brucei: the effect of glycerol on the anaerobic metabolism of glucose.	studies measuring the glycolytic intermediate and adenine nucleotide concentrations in trypanosoma brucei metabolising glucose either aerobically or under conditions where glycerol-3-phosphate oxidase is inactive have shown the following: 1. inhibition with 0.5 mm salicylhydroxamic acid (sham) accurately simulates anaerobic conditions in t. brucei; 2. on inhibition of respiring cells with 0.5 mm sham, the concentrations of most glycolytic intermediates decrease; they decrease further as the conc ...	1980	7464860
studies on the parasitaemia, plasma volumes, leucocyte and bone marrow cell counts, and the moribund state in trypanosoma brucei infection of splenectomised and intact mice.		1980	7467993
lysophospholipase 1 in trypanosoma brucei.	protein fractions from trypanosoma brucei brucei showed lysophospholipase 1 activity (e.e.3.1.1.5), against the substrate 1-acyl-sn-glycero-3-phosphocholine, and also phospholipase a1 activity (e.c.3.1.1.4) by hydrolysis of the 1-acyl bond of 1,2-diacyl-sn-glycero-3-phosphocholine. both enzyme activities were eluted together and showed a 12-fold purification following sephacryl s-200 column chromatography. a final 96-fold increase in activity was obtained by electrophoresis on nondenaturing poly ...	1981	7345684
mixed populations of trypanosoma brucei in a naturally infected pig.		1981	7345685
inhibitory effects of chloramphenicol isomers and other antibiotics on protein synthesis and respiration in procyclic trypanosoma brucei brucei.	the effects of various antibiotics on protein synthesis systems in procyclic trypomastigotes of trypanosoma brucei brucei lump 1026 have been determined in an attempt to identify a mitochondrial translation system. the function of cytoplasmic ribosomes in t. b. brucei in vivo is sensitive to inhibition not only by cycloheximide but also by high concentrations of d-chloramphenicol, l-chloramphenicol, erythromycin and tetracycline as a possible secondary consequence of a primary inhibition of mito ...	1981	7219444
activation of human peripheral blood lymphocytes by a trypanosome-derived mitogen.	activation of human peripheral blood lymphocytes from unsensitized donors by fractions of t.b rhodesiense has been demonstrated in vitro. both t and b cells were stimulated to differentiate into blast cells. purified t cells failed to proliferate, but did so when mitomycin c-treated non-t cells were added. non-t cell proliferation (weak in comparison to the t cell response) was shown to be t-dependent. in unseparated cell cultures. cultures, igm synthesis was enhanced, whilst igg synthesis was u ...	1981	6978210
activation of trypanosome surface glycoprotein genes involves a duplication-transposition leading to an altered 3' end.	expression of the genes for variant surface glycoproteins 117 and 118 in trypanosoma brucei is accompanied by the appearance of an extra copy of these genes, the expression-linked copy, which differs in the surrounding restriction enzyme sites from the corresponding basic copy of the genes. we present direct evidence that the expression-linked copy is the one used for messenger rna synthesis. by s1-nuclease-protection experiments we show that cloned basic-copy genes contain the nucleotide sequen ...	1981	6101223
an immunochemical method for mrna purification. application to messenger rna encoding trypanosome variable surface antigen.	a simplified procedure for isolation of specific mrna using staphylococcus aureus protein a immunoadsorbent chromatography has been developed. this procedure has been applied to the mrna encoding trypanosoma brucei variable surface antigen. trypanosome polyribosomes were reacted with antibodies isolated from an anti-variable antigen-specific serum by protein a-sepharose column chromatography. antibody-bound variable antigen-synthesizing polyribosomes were then separated from unbound polyribosome ...	1981	7462209
bovine immune response to african ;trypanosomes: specific antibodies to variable surface glycoproteins of trypanosoma brucei.	cattle were infected with two different clones of trypanosoma brucei (mitat 1.2 and iltat 1.3) and antibody response was followed by radioimmunoassay. in four of the seven animals there were at least two peaks of antibody activity to the infecting clones, with the second peak much higher than the first. specific antibodies (igg1 and igm but not igg2) were eluted from the immunoabsorbent columns on which the variant surface glycoproteins (vsgs) were coupled. by neutralization of infectivity tests ...	1981	7243343
prevention by polyamines of the curative effect of amicarbalide and imidocarb for trypanosoma brucei infections in mice.		1981	7247968
inhibition of glutathione synthesis as a chemotherapeutic strategy for trypanosomiasis.	with the expectation that trypanosomal glutathione (gsh) plays a major protective role against the endogenous oxidant stress that results form high intracellular levels of h2o2, we sought to deplete trypanosoma brucei brucei of their gsh through inhibition of its biosynthesis. administration of buthionine sulfoximine (bso), a reversible inhibitor of gamma-glutamylcysteine synthetase, to parasitemic mice resulted in a progressive decrease in trypanosome gsh content, such that parasites isolated a ...	1981	7252412
the expression-linked copy of a surface antigen gene in trypanosoma is probably the one transcribed.	the antigenic specificity of the living trypanosome seems to be determined by the protein component of a unique glycoprotein species covering the whole surface of the parasite. during chronic infection, a single clone of trypanosomes may successively express a large repertoire of different variable antigen types (vats). there are probably as many genes as variant-specific antigens (vsas) (see refs 1-3 for reviews). the expression of the genes coding for the synthesis of these antigens is linked ...	1981	7254319
some phenomena associated with the development of trypanosoma brucei rhodesiense infections in the tsetse fly, glossina morsitans.	immature salivary gland (sg) infections averaging 10(3) parasites per fly can apparently develop into mature gland infections averaging 10(5) parasites per fly in as little as 4 days. frequently flies which extrude parasites in their saliva prove to have no parasites in the sg, but often show trypanosomes in the esophagus, cibarial pump, and proboscis. in some instances, sg infections have cleared, resulting in a loss of infectivity. results of studying numbers of parasites regurgitated upon fee ...	1981	7258478
antitrypanosomal action enhanced by photoaffinity labeling with ethidium analogs.	the trypanocidal activity of photoreactive azido analogs of ethidium was tested to determine the suitability of using such compounds as in vivo probes to study the mechanism of the antitrypanosomal activity of ethidium. eight ethidium analogs, including three nonphotoreactive compounds, were tested for their ability to kill t. brucei both with and without photolytic activation. two analogs tested, the monoamino-monoazido isomers, showed greater that 100-fold enhancement of trypanocidal activity ...	1981	7264832
the effects of some african game animal sera in the biit in the trypanosoma (trypanozoon)		1981	7268840