Publications

trypanosome-induced ovarian dysfunction. evidence of higher residual fertility in trypanotolerant small east african goats.	changes in the length of oestrous cycles, plasma progesterone and oestradiol-17 beta levels were monitored for 6 months in trypanosoma congolense-infected normocyclic small east african goats obtained from three tsetse-endemic areas and one tsetse-free area of east africa. irregular oestrous cycles were observed in all infected goats, before cessation at the second cycle post-infection in the more susceptible and fourth cycle in the more resistant goat groups. a significant decline in the proges ...	1988	2903624
berenil (diminazene aceturate)-resistant trypanosoma congolense in cattle under natural tsetse challenge at kibaha, tanzania.	twenty-nine cattle, naturally infected with trypanosoma congolense kibaha, were subjected to chemotherapy with diminazene aceturate (berenil, hoechst) at 3.5 to 14.0 mg/kg. fourteen animals recovered while six were refractory to treatment at 7.0 to 14.0 mg/kg. further treatment of the berenil-resistant isolates with isometamidium chloride (samorin, may and baker) at 1.0 mg/kg, effected cure. corresponding chemotherapeutic trials in mice showed that the isolates were resistant to diminazene acetu ...	1988	2903625
[the use of sentinel animals for the evaluation of the control of vectors of sleeping sickness: preliminary reports at a congolese site].	a large-scale control trial against glossina palpalis palpalis was carried out in the congo using a new trapping technique. in the same way a test related to the experimental utilization of sentinel animals was performed, concurrently to the classical epidemiological and entomological evaluation. 564 domestic animals (pigs, sheep, goats) were examined parasitologically (wet blood films, woo/hct) and serologically (testryps catt) in six villages. when a drastic reduction of tsetse populations was ...	1988	2907260
[chancre: an old-fashioned concept or a modern solution for sleeping sickness?].	a brief introduction on trypanosomiasis in ruminants and an explanation of the term chancre are followed by a discussion of a number of findings on the early pathogenesis of the disease. this study formed part of the requirements in obtaining a doctorate in veterinary medicine.	1988	3051513
trypanosoma congolense: interactions between trypanosomes expressing different metacyclic variable antigen types in vitro and in vivo.	in trypanosome congolense, the surface antigens expressed by cultured metacyclic forms are a limited and serodeme-specific subset of variable antigen types (vats). experiments were carried out in mammalian-form (mf) cultures, comprising dividing trypanosomes which express metacyclic vats (m-vats) maintained in vitro with a mammalian cell feeder layer, or in mice following infection with cultured metacyclic populations. selective neutralization experiments were performed by incubating populations ...	1988	3059264
[effects of sublethal doses of deltamethrin on the pair glossina morsitans morsitans-trypanosoma (nannomonas) congolense].	the presence of trypanosoma in glossina morsitans morsitans induced a decrease in the physiological activity which is expressed in particular by a statistically higher mortality rate of infected flies. a similar effect appears with sublethal doses of deltamethrin either in infected or non infected insects. a cumulative activity of both effects was also observed in infected and treated flies. sublethal doses of the pyrethroid compound showed a delay in feeding, abortions and larval clampings. mor ...	1988	3142654
tsetse immunity and the transmission of trypanosomiasis.	cyclical transmission of african trypanosomes - trypanosoma congolense and subspecies of t. brucei - depends on their uptake by and development within their tsetse fly vectors. tsetse susceptibility to such trypanosome infection seems to be controlled by maternally inherited rickettsia-like organisms (rlos) (fig. 1) and it now seems that the rlos may exert this effect by controlling midgut lectins in the fly. ian maudlin and susan welburn explain the latest findings.	1988	15463060
trypanosome-induced increase in prostaglandin f(2alpha) and its relationship with corpus luteum function in the goat.	plasma progesterone and 13,14-dihydro-15-keto prostaglandin f(2alpha) (pgfm) were measured in normal (uninfected) and trypanosoma congolense -infected adult goats for a period of 121 d, from may to august, during the breeding season in kenya. chronic trypanosomiasis rapidly increased the baseline plasma pgfm levels and the occurrence of irregular pgfm peaks in several infected goats. progesterone luteal levels declined rapidly from the second and subsequent cycles post patency. estrous cycles al ...	1989	16726702
shared surface epitopes among trypanosomes of the same serodeme expressing different variable surface glycoprotein genes.	african trypanosomes evade the immune response of the mammalian host by undergoing antigenic variation, caused by sequence changes in a variable surface glycoprotein (vsg). the majority of trypanosome clones analyzed thus far are not known to share surface exposed epitopes or express appreciably homologous vsgs. we show here that four clones of trypanosoma brucei from the same serodeme express different vsgs and share exposed epitopes to varying degrees, as defined by monoclonal antibodies. rabb ...	1989	2467204
disulfide bond involvement in the maintenance of the cryptic nature of the cross-reacting determinant of metacyclic forms of trypanosoma congolense.	the variable surface glycoprotein (vsg) of african trypanosomes possesses a 1,2-dimyristoylglycosylphosphatidylinositol at the carboxy terminus. cleavage of the 1,2-dimyristoylglycerol (1,2-dmg) moiety from the vsg reportedly results in a higher apparent molecular mass and an increased binding of antibodies against the "cross-reacting determinant" (crd), a cryptic epitope present on most vsgs. using metacyclic forms of trypanosoma congolense, we show that the processes involved are more complex ...	1989	2476173
[ticks and hemoparasitoses of livestock in senegal. iii. the northern sudan area].	the authors describe the results of a study on ticks and hemoparasitoses of cattle and small ruminants in the senegalese north-sudanian area. for 15 months, 40 bovine, 40 sheep and 40 goats received a routine dipping treatment, aimed at the determination of the tick population dynamics together with an accurate localization of the preferential sites for the different species. the following parasites were collected from the animals: hyalomma marginatum rufipes, h. truncatum, rhipicephalus lunulat ...	1989	2485548
fractionation of trypanosome antigens for species-specific sero-diagnosis.	crude somatic antigens from isolated and ultrasonically treated trypanosomes were fractionated by column chromatography. a protein-free antigenic fraction was isolated which reacted monospecifically when tested against hyperimmune sera from rabbits. the method has a potential application in the improvement of serodiagnosis of trypanosomiasis.	1989	2506689
lectin signalling of maturation of t. congolense infections in tsetse.	the process of maturation of trypanosoma congolense broden in tsetse has been shown to be initiated by lectin secreted in the fly midgut. in the present study the duration of lectin signal required to induce maturation was determined by the sequential addition or removal of a specific lectin inhibitor (d+glucosamine) to the diet of infected male glossina morsitans westwood. an established midgut infection of t.congolense was found to require, at most, 72 h exposure to midgut lectin to begin the ...	1989	2519657
use of dna probes to identify trypanosoma congolense and t. simiae in tsetse flies from the gambia.	species- and strain-specific dna probes were used to identify patent midgut infections in glossina morsitans submorsitans and g. palpalis gambiensis captured at four sites in the gambia. 52% of mature nannomonas infections and 12% of immature infections were identified. trypanosoma (nannomonas) simiae accounted for the majority of identified infections in g.m. submorsitans, indicating the importance of distinguishing this species from the closely related t.(n) congolense when assessing the trypa ...	1989	2566262
rickettsial infections of midgut cells are not associated with susceptibility of glossina morsitans centralis to trypanosoma congolense infection.	teneral and 30-day old non-teneral glossini morsitans centralis, from a laboratory-bred colony, were fed on a goat infected with trypanosoma congolense clone il 1180. they were then maintained on an uninfected rabbit, and dissected on day 30 after the infected feed. the midgut infection rates were 38.1% and 8.1%, with the mature infection rates of 28.7% and 4.3%, respectively. electron microscopical examination revealed the presence of rickettsia-like organisms (rlos) within the mycetomes and th ...	1989	2571249
effect of african trypanosomiasis on plasma cortisol and thyroxine concentration in goats.	changes in plasma cortisol and thyroxine (t4) levels were measured weekly in female goats experimentally infected with trypanosoma congolense. values for plasma cortisol (range 10 to 25 nmol litre-1) and t4 (range 65 to 120 nmol litre-1) were within normal ranges in all goats before infection and in control animals throughout the 24 weeks of study. cortisol/t4 ratios of 0.23 to 0.15 (or 1:4 to 1:7) were obtained. in the infected goats a significant increase in cortisol and decline in t4 were sim ...	1989	2595089
a single trypanosome is sufficient to infect a tsetse fly.		1989	2604482
[animal reservoir hosts of trypanosoma brucei gambiense in zaire: trypanosome infections in two foci in bas-zaire].	the prevalence of trypanosoma spp. infections in domestic animals was estimated in a forest (boma) and a savanna (kimpese) sleeping focus in bas-zaire. the miniature anion-exchange centrifugation technique was used to determine the infection rates with t. congolense, t. vivax and t. brucei spp. in 505 animals. t. congolense predominated in both foci with the highest prevalence in pigs (76.2%), followed by sheep (31.3%), dogs (30.6%) and goats (7.4%). t. vivax was seen only on two occasions. in t ...	1989	2617030
antigen-detection enzyme immunoassays for the diagnosis of trypanosoma vivax, t. congolense and t. brucei infections in cattle.	species-specific monoclonal antibodies against trypanosoma vivax, t. congolense and t. brucei were used to develop antigen-capture enzyme-linked immunosorbent assays (antigen-elisa) for the diagnosis of bovine trypanosomiasis. each assay was subsequently used for the detection of species-specific circulating antigens in sera of cattle experimentally infected by tsetse transmission. in t. vivax and in t. congolense-infected animals, circulating antigens were detected as early as 10-12 days post-i ...	1989	2617031
trypanosome infection rate of glossina morsitans submorsitans in bahr el arab, south darfur province, sudan.	trypanosome infection rate of glossina morsitans submorsitans in bahr el arab fly belt, sudan was investigated in four areas using fly rounds with screen and bait animals together with traps during the dry season february to may 1985. the overall infection rate of tests flies captured in the four areas was 5.1%. the infection rate of vivax group trypanosomes comprised 64.7% of total infections, congolense group 31.2% and brucei group trypanosomes 3.9%: 27.3% of the vivax and 31.3% of the congole ...	1989	2617680
[leukocyte migration inhibition after experimental trypanosome infection in cattle].	blood serum from cattle experimentally infected with trypanosomes was tested for its activity influencing granulocyte migration. pooled porcine granulocytes were used in the migration assay. the inhibitory migration activity observed in serum samples of trypanosome infected animals implies the presence of mediators of cellular immunity. values of migration indices express reciprocal events of inhibitory and stimulating events in infected animals. this study allowed to follow at least some aspect ...	1989	2618206
cerebral trypanosomiasis in naturally-infected cattle in the lambwe valley, south nyanza, kenya.	surveys in zebu cattle in the lambwe valley in 1980 indicated that many (up to 70%) were infected with trypanosomes. the predominant parasite was trypanosoma brucei sspl followed by t. congolense. cerebrospinal fluid (csf) analysis showed a high proportion of animals with pleocytosis and elevated total csf protein. trypanosomes were detected in csf and signs of a central nervous system (cns) disease were observed. histopathological lesions in the cns were identical to those found in experimental ...	1989	2619389
effectiveness of wr 163577 against animal trypanosomes in goats and mice.	a bisquinaldine, 1,6-bis-(6-amino-2-methyl-4-quinolylamino) hexane, was tested against trypanosoma brucei ssp. in goats and against t. brucei, t. congolense and t. vivax in mice. at doses of 25 and 100 mg kg-1, the drug protected goats for at least 90 days against blood challenge with t. brucei ssp. fifty to sixty per cent of goats challenged 180 days after treatment were protected, but all goats challenged 270 days after treatment became infected. in mice, bisquinaldine also had a marked effect ...	1989	2619391
effects of splenectomy on trypanosoma congolense infection in cattle.	the role of the spleen in cattle infected with trypanosoma congolense was studied by comparing levels of parasitaemia, blood cell values, and body weights of intact and splenectomized cattle. a total of 28 zebu x hereford steers were used in two separate experiments. seven animals were splenectomized at least four weeks prior to infection and two others were splenectomized 128 days after infection. splenectomized animals were compared to 12 intact infected animals and seven intact uninfected con ...	1989	2619394
trypanosoma congolense: erythrocyte indices, plasma iron turnover and effects of treatment in infected cattle.	early during the course of trypanosoma congolense infection in cattle decreases in pcv occurred and coincided with increases in both mcv and mch. the indices reached highest levels between eight and 12 weeks post-infection. by week 20 of infection mcv and mch had decreased to pre-infection levels even though a substantial anemia persisted. serum iron levels were elevated at eight weeks postinfection. (infected 271 mg dl-1 v. control 140 mg dl-1) but decreased to low levels in infected animals by ...	1989	2619395
detection of parasite peptidase in the plasma of heifers infected with trypanosoma congolense.	plasma samples from heifers infected with trypanosoma congolense were shown to contain a parasite peptidase. in some instances, trypanosome peptidase was detected in plasma samples taken from heifers for up to 14 days after infections had been successfully treated with diminazene aceturate (berenil). trypanosome peptidase was detected in plasma using starch gel electrophoresis and also by a dot blot assay in which a mcab, raised against the enzyme, was spotted onto nitrocellulose filters which w ...	1989	2651915
expression of trypanosoma congolense trypanothione reductase in escherichia coli: overproduction, purification, and characterization.	the cloned trypanothione reductase gene from trypanosoma congolense has been expressed in escherichia coli to a level of 1% of the soluble protein. this has allowed facile purification and initial characterization of the reductase, and it appears by all criteria to be a representative member of the trypanothione reductase family. most importantly, it shows the same exclusive substrate specificity for trypanothione over glutathione characteristic of other trypanothione reductases examined to date ...	1989	2669965
biomedical science and the third world. under the volcano. trypanothione reductase.		1989	2698087
chemoprophylaxis of trypanosomiasis, due to trypanosoma (nannomonas) congolense, in rabbits using a slow release device containing homidium bromide.	the prophylactic activity of a subcutaneously implanted slow release device, containing homidium bromide, was assessed in rabbits, challenged with different stocks of t. congolense, and compared with the classical treatment of 1 mg homidium bromide/kg b.w. intramuscularly. the prophylactic activity of the intramuscular injection was less than a month, while the slow release device protected the rabbits against seven challenges with t. congolense during a period of more than 300 days.	1989	2698124
interference in the establishment of tsetse-transmitted trypanosoma congolense, t. brucei or t. vivax superinfections in goats already infected with t. congolense or t. vivax.	an interference phenomenon that delays superinfection with a trypanosome species different from that used for the initial infection has been found to occur in goats. following tsetse transmission of trypanosoma brucei to goats already infected with t. congolense, there was a delay in chancre development, as well as in the appearance of t. brucei and anti-t. brucei antibodies in the blood when compared to previously uninfected goats. however, there was no delay in the establishment of a tsetse-tr ...	1989	2705284
occurrence of human serum-resistant trypanosoma congolense in goats and sheep in nigeria.	an assessment of the role of dogs, goats and sheep as reservoir hosts of african trypanosomes infective for humans (sleeping sickness) was carried out in nigeria during a 2-year study period. twelve stocks of trypanosoma (trypanozoon) brucei, 10 stocks of trypanosoma congolense and 11 stocks of trypanosoma vivax were isolated from a total of 699 animals, comprising 286 sheep, 221 goats and 192 dogs. the potential infectivity of the isolates for man was tested in vitro using the blood incubation ...	1989	2741299
comparative trypanotolerance of the small east african breed of goats from different localities to trypanosoma congolense infection.	differences in susceptibility of the small east african breed of goats to an experimental trypanosoma congolense infection were investigated. the goats were obtained from different areas of east africa, morogoro and arusha (tanzania), imbo and lambwe valley (kenya). morogoro goats were found to be more tolerant, followed by arusha, lambwe valley and imbo goats, in that order. the imbo goats had highest parasitaemia, more severe anaemia, marked weight losses and highest mortality rate. the morogo ...	1989	2741304
evidence for diploidy in metacyclic forms of african trypanosomes.	the dna contents of bloodstream form trypanosomes (life cycle stages circulating in the blood of the vertebrate host) of four african trypanosoma species and of metacyclic forms (the life cycle stage that is injected into the vertebrate by the tsetse fly during its bite) of the same four species were measured by cytofluorometry of individual cells or nuclei. the results showed unambiguously that the metacyclic forms cannot be considered to be products of meiosis containing only half of the dna o ...	1989	2748597
interference between drug-resistant and drug-sensitive stocks of trypanosoma congolense in goats.	a study was undertaken in goats to investigate the ability of two unrelated stocks of trypanosoma congolense, one of which is highly sensitive to isometamidium chloride and one which is drug-resistant, to become established in the presence of an existing infection with the other stock. the goats, which were initially infected with the sensitive strain and were then challenged with the resistant strain, were cured by treatment at 0.1 mg kg-1 isometamidium, indicating that the resistant stock did ...	1989	2772408
endocytosis by african trypanosomes. i. three-dimensional structure of the endocytic organelles in trypanosoma brucei and t. congolense.	african trypanosomes multiply rapidly during the course of infection obtaining nutrients from the host blood and other body fluids. the organelles involved in endocytosis were revealed ultrastructurally using horseradish peroxidase (hrp) and colloidal gold coupled to bovine transferrin (au-tf) or bovine serum albumin (au-bsa). at 0 degree c the markers bound to the cell surface and neither entered the flagellar pocket nor were internalized. upon warming to 37 degrees c, the markers were found in ...	1989	2776775
endocytosis by african trypanosomes. ii. occurrence in different life-cycle stages and intracellular sorting.	horseradish peroxidase (hrp) and colloidal gold-labeled proteins enter many of the endocytic organelles of bloodstream forms of trypanosoma brucei and t. congolense. however, the colloidal gold markers were excluded from substantial parts of the pathway that contained hrp. morphometric studies revealed that hrp entered organelles that accounted for approximately 5% of the total cell volume while transferrin-gold entered organelles that comprised approximately 2% of the total cell volume. in addi ...	1989	2776776
camel trypanosomiasis and its vectors in somalia.	blood samples from 3000 somali camels (camelus dromedarius) were examined for trypanosome infection. of these, 160 (5.33%) were infected with trypanosoma evansi, one (0.03%) with t. congolense and one (0.03%) with t. brucei. camel trypanosomiasis occurred in most areas of tabanid infestation throughout the country. the tabanids philoliche zonata and p. magretti are incriminated as the major vectors of the disease.	1989	2781715
the influence of trypanosoma congolense infection on the disposition kinetics of diminazene aceturate in the dog.	diminazene aceturate was administered intravenously at 3.5 mg/kg body weight to mongrel dogs before and after infection with trypanosoma congolense. plasma and urine were collected at varying intervals thereafter and analysed for the compound. the mean area under the concentration-time curve (auc) of diminazene in healthy dogs was 25.8 h.micrograms/ml but was significantly increased (p less than 0.05) to 35.7 h.micrograms/ml after infection with t. congolense. the distribution half-life was sign ...	1989	2781721
bovine trypanosomiasis in southern tanzania: investigation into the incidence of infection and duration of chemoprophylaxis.	before implementing chemoprophylaxis to control bovine trypanosomiasis it is essential to have epidemiological data upon which to base control regimes. a study was conducted under natural tsetse challenge with two groups each of 12 calves grazing their first season. group 1 received isometamidium treatments prophylactically at intervals during the rainy season and calves in group 2 were treated individually with diminazene as they become infected with trypanosomes. infections were first detected ...	1989	2787560
detection of trypanosoma congolense and trypanosoma brucei subspecies by dna amplification using the polymerase chain reaction.	the nuclear dna of trypanosoma congolense contains a family of highly conserved 369 base pair (bp) repeats. the sequences of three cloned copies of these repeats were determined. an unrelated family of 177 bp repeats has previously been shown to occur in the nuclear dna of trypanosoma brucei brucei (sloof et al. 1983a). oligonucleotides were synthesized which prime the specific amplification of each of these repetitive dnas by the polymerase chain reaction (pcr). amplification of 10% of the dna ...	1989	2797872
factors affecting duration and intensity of trypanosome infection of domestic animals.	domestic animals can become infected with several species of trypanosomes that are transmitted by tsetse, including trypanosoma congolense, t. vivax, t. brucei, t. simiae, t. rhodesiense and t. gambiense. the intensity and duration of the resulting parasitaemia are affected by the parasite, the host and detection methods. techniques currently used to detect parasites range in sensitivity from one to 10(5) organisms per ml. at the same time, parasite kinetics vary greatly both within and between ...	1989	2802820
calculating the basic reproductive rate ro when there are 2 or more pathogens.	some reasons why observed prevalences of the 3 major trypanosomes in cattle and livestock animals might not be independent are discussed. apart from genuine interactions between the infections, averaging over heterogeneous populations produces an apparent correlation between pathogens. more subtly, chemotherapy and mortality both induce a positive correlation between pathogens. the calculation of the basic reproductive rate ro for one pathogen in the endemic presence of another is explained, and ...	1989	2802830
trypanosoma congolense: drug resistance during cyclical transmissions in tsetse flies and syringe passages in mice.	a drug-resistant trypanosoma congolense strain with predetermined curative doses (cd50 and cd90) of samorin at 13.9 +/- 1.02 and 20.3 +/- 1.13 mg/kg body weight, respectively, was cyclically transmitted through tsetse flies and by syringe passages in mice in the absence of drug pressure. the changing levels of drug sensitivity were determined after every 3rd cyclic and 5th syringe passage intervals. it was noted that when the strain was maintained in tsetse flies through 12 cyclical transmission ...	1989	2806460
identification of a theileria mutans-specific antigen for use in an antibody and antigen detection elisa.	purified piroplasms of theileria mutans were used to immunize balb/c mice to generate monoclonal antibodies (moabs). the moabs recognized an antigen of a relative molecular mass of 32 kda in western blots. this antigen was also recognized by sera from cattle which had recovered naturally from experimental tick-transmission or infections induced by the blood stages of t. mutans. the moabs did not react, in indirect immunofluorescence or enzyme-linked immunosorbent assays (elisa), with the common ...	1990	1698274
parasite kinetics and cellular responses in goats infected and superinfected with trypanosoma congolense transmitted by glossina morsitans centralis.	trypanosoma congolense infected tsetse were fed on the flanks of goats at sites drained by the prefemoral lymph node. the efferent lymphatic of this lymph node was surgically cannulated and the lymph was collected daily and examined for appearance of parasites, lymph flow and cells. trypanosomes were detected in the lymph 4 days after infection, which was 2 days prior to the appearance of the local skin reaction or the presence of parasites in the blood. once the animal became parasitaemic, tryp ...	1990	1967506
the effect of temperature and storage on the infectivity and motility of african animal trypanosomes in the blood of different hosts.	blood from mice, rats, goats or cattle infected with trypanosoma congolense, t. vivax or t. brucei was stored at 0-4 degrees c, 20-25 degrees c, 30-35 degrees c or 36-40 degrees c. each sample was examined after set intervals to determine the maximum period the trypanosomes could remain motile and infective. t. brucei in blood remained motile for 96 h at 0-4 degrees c, being the longest period that was observed, but remained infective for only 8 h. t. vivax survived poorly in rodent blood, but d ...	1990	1967509
expression of resistance to isometamidium and diminazene in trypanosoma congolense in boran cattle infected by glossina morsitans centralis.	investigations were conducted on the sensitivity to isometamidium chloride (samorin) and diminazene aceturate (berenil) of derivatives of three of the trypanosoma congolense stocks isolated between 1978 and 1983 from zebu cattle in the bobo-dioulasso region of burkina faso. boran cattle were used in the drug-sensitivity tests and were infected using glossina morsitans centralis. the results showed that t. congolense stock il 2466 isolated in 1978 was sensitive to the standard therapeutic dose of ...	1990	1969704
stability of metacyclic variable antigen types (m-vats) during the early stages of infection with trypanosoma congolense.	expression of nine metacyclic variable antigen types (m-vats) of trypanosoma congolense in chancres from infected rabbits was determined using monoclonal antibodies raised against metacyclic forms of trypanosomes. trypanosomes present in chancres 7-9 days post infection expressed m-vats present in metacyclic populations of the parasites. the majority of m-vats expressed showed little proportional change from those observed on metacyclic trypanosomes during this period although expression of one ...	1990	1971489
homidium bromide as a chemoprophylactic for cattle trypanosomiasis in kenya.	homidium bromide was used in a strategic chemoprophylactic regime to control trypanosomiasis in boran cattle in kenya. trypanosome infection rates in cattle receiving homidium bromide prophylaxis were compared with those in control cattle which received no prophylaxis but were treated with diminazene aceturate when infected. homidium bromide was administered twice during the year after which no infections were detected for periods of nineteen weeks and seventeen weeks respectively. the drug sens ...	1990	1971490
improved identification of nannomonas infections in tsetse flies from the gambia.	trypanosomes from 36 midgut infections were isolated in procyclic culture from glossina morsitans submorsitans and g. palpalis gambiensis in the gambia. twenty-eight stocks (78%) were identified using dna probes specific for: (a) trypanosoma (nannomonas) congolense savannah type, (b) t. (n.) congolense riverine-forest type, (c) t. (n.) simiae and (d) trypanozoon, t. simiae and savannah type t. congolense were found only in g.m. submorsitans while the riverine-forest type t. congolense was restri ...	1990	1980568
evaluation of a field test for trypanotolerance in young n'dama cattle.	in three separate tests in 1987, 1988 and 1989, a total of 436 one-year-old n'dama cattle were maintained for 12, 18 and 24 weeks under a medium natural tsetse-trypanosome challenge in gabon, central africa. matching health and performance data were recorded on 4, 10 and 13 occasions respectively, to allow simultaneous evaluation of the effect of different criteria of trypanotolerance on animal performance. under trypanosome prevalences of 25, 31 and 9%, respectively, ability to control the deve ...	1990	1980803
salivary gland infection: a sex-linked recessive character in tsetse?	male tsetse, when infected in the laboratory with trypanosomes of the subgenus trypanozoon, usually produce greater salivary gland infection rates than females of the same species. we show that a single sex-linked gene model can be fitted to most recently published data for salivary gland infection rates in tsetse. the maturation of trypanosoma congolense infections is shown to be independent of fly sex. the possible effects of genetic control of maturation of trypanozoon infections in tsetse po ...	1990	1980807
differential expression of a family of putative adenylate/guanylate cyclase genes in trypanosoma brucei.	the expression site for the variant surface glycoprotein (vsg) gene of trypanosoma brucei contains several genes of unknown function (esags, for expression site-associated genes). among these, esag 4 shows homology to eukaryotic adenylate/guanylate cyclase genes, in the region encoding the presumptive enzyme catalytic domain. this gene belongs to a family of related sequences, and hybridizes to the genomic dna of other trypanosomatids, such as trypanosoma congolense, trypanosoma vivax and trypan ...	1990	1982555
trypanosoma congolense bloodstream forms evade complement lysis in vitro by shedding of immune complexes.	in the presence of antibodies against the variant surface glycoprotein (vsg) and guinea pig complement, trypanosoma congolense bloodstream forms were lysed. parasites, which had been preincubated with antibodies at 37 degrees c before addition of complement, escaped from complement lysis in a time- and temperature-dependent process. preincubation caused removal of the antibodies from the cell surface by formation of filopodia and accumulation of the immune complexes between aggregated cells. add ...	1990	2081529
cellular phenotypes in trypanosoma congolense infected sheep: the local skin reaction.	mononuclear cell subpopulations in local skin reactions (chancres) in sheep infected with metacyclic forms of trypanosoma congolense were studied by indirect immunoperoxidase staining using a panel of monoclonal antibodies (moabs) specific for ovine leucocyte subsets. morphometric analysis revealed significant increases in numbers of cells expressing cd5, cd4, cd8, cd45r (mainly b cells), major histocompatibility complex (mhc) class ii antigens, fc receptors (fcr) on macrophages (vpm32) and fcr ...	1990	2084609
identification of midgut trypanolysin and trypanoagglutinin in glossina palpalis sspp. (diptera: glossinidae).	a midgut trypanolysin and an agglutinin from glossina palpalis subspecies were isolated and partially characterized using anion-exchange chromatography and polyacrylamide gel electrophoresis. fplc fractions of midgut extracts of glossina palpalis palpalis caused agglutination and lysis of two trypanosome species (trypanosoma congolense and trypanosoma brucei brucei), although glossina palpalis gambiensis caused only agglutination. the trypanolysin and agglutinin were active only in the posterior ...	1990	2092294
[improvement of the reproducibility of the elisa test for detecting anti-trypanosoma congolese antibodies in cattle].	simplicity and the potential automatization make the elisa test a universal tool for the detection of antibodies, and, more recently, of antigens. but the reproducibility of results is not very good, due to many varying factors. we tried to improve the reproducibility of the elisa test for the detection of anti-trypanosoma congolense antibodies in cattle. for that, buffers are always used at room temperature to avoid temperature gradients in the plates. all volumes are increased to 200 microlite ...	1990	2092352
[sensitivity of double microcentrifugation for the research of trypanosomes].	the double microcentrifugation technique, described by kratzer and ondiek (1989) for the parasitological diagnosis of trypanosomes, has been tested both in the laboratory and in the field. the limits of detection obtained here were not as low as those described in the original experiment, but the sensitivity of this technique for the detection of trypanosoma brucei, t. congolense and t. vivax was better than the phase contrast buffy coat method. this technique, which is easy to apply in the fiel ...	1990	2103054
immunosuppression in caprine trypanosomiasis: effects of acute trypanosoma congolense infection on antibody response to anthrax spore vaccine.	trypanosoma congolense infected goats were vaccinated with bacillus anthracis spore vaccine to determine the effect of such infection on the humoral immune response to the vaccine. the anti-anthrax antibody levels were severely depressed in infected goats. when trypanocidal therapy was administered to t. congolense infected goats 14 days after infection they developed antibody levels against bacillus anthracis similar to uninfected controls.	1990	2115214
multiple superovulations in n'dama heifers.	five n'dama heifers were superovulated with follicle stimulating hormone (fsh-p or folltropin) a total of six times each. the superovulations were carried out between ongoing experimental trypanosoma congolense infections. twenty-four (80%) of the 30 superovulations had a good ovarian response with 21 (70%) producing an average of 2.7 +/- 0.4 (mean +/- s.e.m.) embryos. the highest embryo production was achieved at the third and fourth superovulation, after which both the number of embryos and th ...	1990	2120824
haemolymph lectin and the maturation of trypanosome infections in tsetse.	the tsetse immune system has recently been shown to be involved in trypanosome maturation; lectin secreted in the midgut, normally responsible for preventing the establishment of midgut infections, induces established midgut trypanosomes to mature. we now show that a second lectin, present in tsetse haemolymph, is essential to complete the maturation process. interactions between tsetse lectins and parasite surface coats probably determine trypanosome transmissibility and may be partly responsib ...	1990	2132968
specific probes for trypanosoma (trypanozoon) evansi based on kinetoplast dna minicircles.	trypanosoma evansi is difficult to distinguish from other members of subgenus trypanozoon, save for its inability to develop cyclically in the tsetse fly and its characteristic kinetoplast dna (kdna). we have used cloned kdna minicircle fragments as specific probes to distinguish t. evansi from other trypanosomes of subgenus trypanozoon. two probes were required, each specific for one of the subgroups of t. evansi previously described. probe a reacted only with the major isoenzyme group of t. ev ...	1990	2163493
trypanosoma congolense: appearance and distribution of variable antigen types during metacyclic differentiation in vitro.	differentiation of epimastigotes and production of infective metacyclic forms of trypanosoma congolense were examined in a culture system which enabled manipulation of the population density of insect forms. scanning electron microscopy of cultures revealed the attachment sites of epimastigotes in detail, showing them to be attached as 'clusters' or 'bundles' and having associated fibrillar structures. dividing epimastigotes were observed either within individual bundles or in association with t ...	1990	2179830
effects of the combination of dl-alpha-difluoromethylornithine and diminazene aceturate in trypanosoma congolense infection of dogs.	the therapeutic activity of a combination of difluoromethylornithine (dfmo) with diminazene aceturate was investigated in mongrel dogs experimentally infected with trypanosoma congolense. the criteria used in the assessment of the trypanocidal effect of the therapy include the examination of the blood for parasites, as well as clinical and haematological changes at intervals following treatment. diminazene aceturate and dfmo alone and in combination produced intermittent aparasitaemia in the dog ...	1990	2238433
role of the chancre in induction of immunity to tsetse-transmitted trypanosoma (nannomonas) congolense in goats.	local skin reactions (chancres) developed in goats at the sites of deposition, by tsetse flies, of metacyclics of trypanosoma congolense. the chancres developed much faster and were more pronounced when ten infected tsetse were allowed to feed on a spot as compared to only one fly per spot. the initial host cellular reaction in the chancre was predominantly polymorphonuclear, followed at the peak of development of the chancre by a predominantly lymphoblastic and plasmacytic reaction. trypanosome ...	1990	2251766
comparison of the susceptibility to deltamethrin of female glossina morsitans morsitans westwood, 1850 (diptera: glossinidae) uninfected and infected with trypanosoma (nannomonas) congolense broden, 1904 (kinetoplastida, trypanosomatidae).	the susceptibility of pregnant female glossina morsitans morsitans westwood, 1850 infected with trypanosoma (nannomonas) congolense broden, 1904 to deltamethrin, a synthetic pyrethroid insecticide, was compared to that of pregnant uninfected females. the results showed that infected flies have a significantly higher mortality rate than uninfected ones, and have a reduced longevity compared with uninfected control flies. these experiments suggest that the effects of trypanosome infection on gloss ...	1990	2256771
characterization of trypanosoma congolense serodemes in stocks isolated from chipata district, zambia.	six stocks of trypanosoma congolense were cloned from 17 stocks isolated from eastern zambia and used to initiate insect-form in vitro cultures producing metacyclic trypanosomes. serological assays were then developed using these in vitro-derived metacyclics as a reference collection of antigens. monoclonal antibodies recognized 8 metacyclic variable antigen types (m-vats) of one stock, t. congolense treu 1885, representing 70-80% of that stock's m-vat repertoire, and in an indirect fluorescent ...	1990	2263418
immunohistochemical demonstration of trypanosoma evansi in tissues of experimentally infected rats and a naturally infected water buffalo (bubalus bubalis).	trypanosoma evansi was demonstrated by an immunohistochemical technique in formalin-fixed paraffin-embedded tissues of experimentally infected rats. trypanosoma evansi was visible readily, nuclei were stained darkly, the cytoplasm was stained moderately, and the cell membranes were delineated clearly. the parasites were present in small- to large-sized blood vessels of all organs, in extravascular spaces of ventricles and neuropil of the brain, and in interstitial tissues of the lung and testes. ...	1990	2319414
experimental infection of n'dama cattle with trypanosomes using glossina palpalis gambiensis caught in the wild.	the transmissibility of trypanosome infection to n'dama cattle by tsetse flies caught in the field was examined. wild-caught glossina palpalis gambiensis were transferred singly into small numbered cages and allowed to feed on 14 uninfected n'dama cattle. following a completed feed the tsetse were dissected and infection in the proboscis, the salivary glands and the gut was recorded. each animal was bitten by a number of tsetse ranging from five up to 64 flies. following dissection of the tsetse ...	1990	2321260
trypanosoma congolense: complement independent immobilization by a monoclonal antibody.		1990	2323399
pathological changes in male genitalia of cattle infected with trypanosoma vivax and trypanosoma congolense.	samples for histological studies were taken from the genitalia of 14 bulls (five infected with trypanosoma vivax, five with t. congolense and four uninfected control animals), slaughtered 12, 22 or 30 weeks post-infection. infection with y58 strain of t. vivax and strain 2295 of t. congolense caused various grades of lesions in the male reproductive organs, especially the testes and epididymides. t. congolense produced more severe degenerative changes than t. vivax. it is concluded that in long- ...	1990	2331595
effect of novidium (homidium chloride) chemotherapy on genital lesions induced by trypanosoma vivax and trypanosoma congolense infections in zebu bulls.	zebu bulls chronically infected with trypanosoma vivax and t. congolense were treated at the 12th week post-infection with novidium and slaughtered at different times after treatment to determine histological evidence of healing of the genital lesions. though trypanosomes disappeared from the blood soon after chemotherapy, there was incomplete resolution of genital lesions even 10-18 weeks later. where there is severe degeneration of the testes and epididymes chemotherapy may be ineffective in l ...	1990	2331596
trypanosoma congolense: an in vitro assay to distinguish drug-resistant from drug-sensitive populations.	an in vitro assay to distinguish drug-resistant from drug-sensitive populations of trypanosoma congolense has been developed. the incorporation of radiolabelled hypoxanthine by procyclic trypanosomes in vitro was measured after 48 h exposure to different concentrations of trypanocides. in the presence of either isometamidium chloride (samorin) or diminazene aceturate (berenil), the ability of procyclics of a drug-sensitive stock (treu 1627) to incorporate hypoxanthine at 28 degrees c was impaire ...	1990	2336447
comparative haematological changes following trypanosoma vivax and t. congolense infections in zebu bulls.	a comparative study of haematological changes subsequent to trypanosoma vivax and trypanosoma congolense infections was carried out using 24 zebu bulls during a period of 12 weeks. eight bulls were infected with t. vivax, another eight with t. congolense and eight served as controls. infected bulls developed chronic trypanosomiasis which was characterized by many clinical manifestations including intermittent pyrexia. elevated rectal temperatures of up to 105 and 106 degrees f were recorded, res ...	1990	2343522
serum haemolytic complement activity and c3 levels in bovine trypanosomosis under natural conditions of challenge--early indications of individual susceptibility to disease.	twenty-five baoule (bos taurus) and 12 zebu (bos indicus) cattle, which were part of an experiment aimed at characterizing cattle for resistance to trypanosomosis under natural challenge in burkina faso, were monitored for complement levels. total haemolytic activity of the alternative complement pathway and c3 in sera taken weekly were estimated. the results were analysed in relation to the course of the disease, parasitological data, packed red cell volume (pcv) and body weight. all the animal ...	1990	2343531
susceptibility of african buffalo and boran cattle to trypanosoma congolense transmitted by glossina morsitans centralis.	four african buffalo (syncerus caffer) and four boran cattle (bos indicus) were each exposed to the bites of 10 tsetse flies infected with trypanosoma congolense. although both groups of animals became infected, the buffalo showed no clinical signs of trypanosomiasis while the cattle suffered from the disease characterized by pronounced skin reactions, high parasitaemia and severe anaemia. the prepatent periods in the buffalo varied from 18 to 27 days in comparison with 11 to 14 days in the catt ...	1990	2343539
recombinant dna probes reveal simultaneous infection of tsetse flies with different trypanosome species.	the utility of recombinant dna probes in the detection of natural trypanosome infection of tsetse flies has been assessed in lambwe valley, near the shores of lake victoria, kenya. the tsetse flies were surveyed during two different seasons in 1988. three different probes used each contained highly repetitive dna sequences specific for a species or subspecies of trypanosomes of the nanomonas subgenus. a fourth probe contained repetitive sequences common to trypanosome species of the trypanozoon ...	1990	2362604
susceptibility of african buffalo and boran cattle to intravenous inoculation with trypanosoma congolense bloodstream forms.	this study compares the susceptibility of african buffalo (syncerus caffer) and boran cattle (bos indicus) to intravenous infection with t. congolense blood stream forms. the trypanosomes multiplied in the buffaloes and the boran and reached levels of detectable parasitaemia 4 days after infection in the boran and 10 days after infection in the buffalo. the cattle developed severe anaemia and had to be treated 60 days after infection to save them from dying whereas the buffaloes did not develop ...	1990	2382098
application of luminol-dependent chemiluminescence to assay opsonizing antibodies to procyclic forms of trypanosoma congolense in the sera of dogs experimentally infected with heterologous stocks.	luminol-dependent chemiluminescence (lcl) responses of dog granulocytes were used to assay opsonizing antibodies to procyclic culture forms of t. congolense. a high degree of sensitivity was demonstrated and lcl levels were high, when the phagocytic cells were incubated with the sera of infected dogs even at dilutions as high as 1:400 as compared to pre-infection or negative sera. the levels of opsonizing antibodies were elevated in all the dogs throughout the time of observation. the technique ...	1990	2382102
effect of chemotherapy on elevated ejaculation time and deteriorated semen characteristics consequent to bovine trypanosomiasis.	the effect of the trypanocidal drug novidium on elevated ejaculation time and deteriorated semen characteristics was studied in zebu cattle infected with t. vivax and t. congolense. two groups, comprising six bulls per group, were infected with trypanosoma vivax or trypanosoma congolense while three bulls served as controls. chemotherapy was carried out 12 weeks post-infection on three bulls from each group, leaving three bulls untreated while three bulls served as uninfected controls. blood sam ...	1990	2397378
association of infectivity, parasitaemia and virulence in a serodeme of trypanosoma congolense.	quantitative methods were adopted to study the course of trypanosoma congolense infection in mice and goats. the ease of initiating infection with a single organism (clone) was found to show a smooth correlation with the virulence of 24 isolates. virulence of t. congolense was found to be directly related to the degree of viability of the parasite but inversely proportional to the capacity of the host to limit parasitaemia. isolates obtained from the goat in the early stage of the infection were ...	1990	2399650
conserved sequences in the u2 snrna-encoding genes of kinetoplastida do not include the putative branchpoint recognition region.	the u2 small nuclear rna (snrna) of trypanosoma brucei gambiense, a flagellated protozoon of the order kinetoplastida, is 148 nucleotides (nt) long, and thus the smallest u2 snrna identified so far. to examine the evolutionary conservation of this rna among kinetoplastida, we have cloned and sequenced the u2 genes from trypanosoma congolense and leishmania mexicana amazonensis, which are 145 and 141 nt in length, respectively. the sequences of the kinetoplastida u2 snrnas are essentially identic ...	1990	2401409
elevation of morphological abnormalities of spermatozoa in the semen of zebu bulls consequent to trypanosoma vivax and trypanosoma congolense infections.	twenty-four zebu bulls were used in a 12-wk long study. eight bulls were infected with t. vivax , eight others with t. congolense and eight bulls served as controls. all the infected bulls developed chronic trypanosomiasis. mean percentage base-line values prior to infection for acrosomal, sperm-head, detached heads, proximal cytoplasmic droplets, distal cytoplasmic droplets, sperm-tail, midpiece and total sperm morphological abnormalities ranged between 0.1+/-0.1 for acrosomal and 8.7+/-3.4 for ...	1990	16726788
endopeptidase variations among different life-cycle stages of african trypanosomes.	lysates of different life-cycle stages of trypanosoma congolense, trypanosoma vivax and trypanosoma brucei were analysed for endopeptidase activity, using reaction conditions which permitted a distinction to be made between lysosomal and non-lysosomal activity [lonsdale-eccles, j. d. & grab, d. j. (1987) eur. j. biochem. 169, 467-475]. hydrolysis of z-arg-arg-nhmec (z = benzyloxycarbonyl, nhmec = 7-amino-4-methylcoumaryl) and z-gly-gly-arg-nhmec occurred predominantly at alkaline ph and was obse ...	1991	1991468
mutational analysis of parasite trypanothione reductase: acquisition of glutathione reductase activity in a triple mutant.	african trypanosomes contain a cyclic derivative of oxidized glutathione, n1,n8-bis(glutathionyl)spermidine, termed trypanothione. this is the substrate for the parasite enzyme trypanothione reductase, a key enzyme in disulfide/dithiol redox balance and a target enzyme for trypanocidal therapy. trypanothione reductase from these and related trypanosomatid parasites is structurally homologous to host glutathione reductase but the two enzymes show mutually exclusive substrate specificities. to ass ...	1991	2007114
sensitivity of an antigen detection enzyme immunoassay for diagnosis of trypanosoma congolense infections in goats and cattle.	the sensitivity of a monoclonal antibody-based antigen-detection enzyme immunoassay (antigen-elisa) for the diagnosis of trypanosoma congolense was evaluated using sera from experimentally infected goats and cattle. ten goats (galla x east african masai) and 7 steers (bos indicus) were infected with different clones of t. congolense and left to run a chronic course for 46 and 24 mo, respectively. during this period, monthly blood samples were collected and analyzed for the presence of trypanosom ...	1991	2010855
variation in resistance to isometamidium chloride and diminazene aceturate by clones derived from a stock of trypanosoma congolense.	nine clones were derived from a drug-resistant trypanosoma congolense stock (il 2856) and characterized in mice for their sensitivity to isometamidium chloride and diminazene aceturate. all clones were derived from the stock without drug selection and expressed high levels of resistance to isometamidium chloride (50% curative dose [cd50] values ranging from 1.5 to 5.1 mg/kg) and intermediate to high levels of resistance to diminazene aceturate (cd50 values ranging from 5.1 to 21.0 mg/kg). by con ...	1991	2038504
redox enzyme engineering: conversion of human glutathione reductase into a trypanothione reductase.	the substrate specificity of the human enzyme glutathione reductase was changed from its natural substrate glutathione to trypanothione [n1,n8-bis(glutathionyl)spermidine] by site-directed mutagenesis of two residues. the glutathione analogue, trypanothione, is the natural substrate for trypanothione reductase, an enzyme found in trypanosomatids and leishmanias, the causative agents of diseases such as african sleeping sickness, chagas disease, and oriental sore. the rational bases for our mutat ...	1991	2059620
[infection of glossina palpalis palpalis (diptera, glossinidae) by trypanosomes in the forest zone of gagnoa in the ivory coast].	2,153 glossina palpalis palpalis caught in biconical traps from different biotopes in relation with human activities in the forest areas of côte d'ivoire were used to calculate the trypanosome infection rates. the results showed that there was no preferential biotope for glossina infected by trypanosomes. the most widespread species of trypanosomes infecting glossina p. palpalis is t. congolense (10.13%) followed by t. vivax (8.22%) and seldomly by t. brucei (0.70%). female glossina are infected ...	1991	1665576
clone-specific immune colostrum induces increased resistance in goat kids challenged with trypanosoma congolense.	the course of infection and the humoral immune response to trypanosoma congolense clone ilnat 3.1 were studied in test goat kids receiving colostrum from dams immunized with the surface coat of ilnat 3.1 and control kids that received colostrum from nonimmunized dams. at 24-48 h after birth, all test kids had detectable serum antibodies to the trypanosome clone. there was no difference in the prepatent period between the test and control kids following challenge with 10(3) t. congolense ilnat 3. ...	1991	1678573
therapeutic and prophylactic activity of isometamidium chloride against a tsetse-transmitted drug-resistant clone of trypanosoma congolense in boran cattle.	an investigation was conducted on the therapeutic and prophylactic activity of isometamidium chloride (samorinr) in boran (bos indicus) cattle against a trypanosoma congolense clone, il 3270. this clone was derived, without drug selection, from a stock originally isolated in burkina faso and has previously been shown to be resistant to isometamidium in both cattle and mice using an infection and treatment regimen. a group of 5 cattle were treated intramuscularly with 1.0 mg kg-1 isometamidium ch ...	1991	1678576
differences between n'dama and boran cattle in the ability of their peripheral blood leucocytes to bind antibody-coated trypanosomes.	investigations were undertaken to evaluate the immune response of trypanotolerant n'dama (bos taurus) and susceptible boran (bos indicus) cattle to two trypanosoma congolense variable antigen types (vats) expressed in both breeds following tsetse-transmitted challenge. the vat-specific antibodies of both igm and igg1 isotypes produced by both breeds had similar neutralizing titres. the interaction between immune sera, trypanosomes and freshly isolated peripheral blood leucocytes (pbl) from uninf ...	1991	1680277
pathogenicity of tsetse-transmitted trypanosoma congolense for waterbuck (kobus defassa) and boran cattle (bos indicus).	five waterbuck (kobus defassa) and four boran cattle (bos indicus) were infected with trypanosoma congolense il2895 using glossina morsitans morsitans. at the same time, two waterbuck and two cattle were inoculated intravenously with bloodstream forms. with both methods of challenge, cattle had short prepatent periods followed by a continuous high parasitaemia. all cattle became severely anaemic and had to be treated with trypanocidal drugs to prevent death. in contrast, tsetse and intravenous c ...	1991	1685298
infection rates in glossina morsitans morsitans fed on waterbuck and boran cattle infected with trypanosoma congolense.	teneral glossina morsitans morsitans were fed on waterbuck (kobus defassa) and boran cattle (bos indicus) infected experimentally with trypanosoma congolense clone il2895. infection rates in tsetse varied from 9 to 31% when fed on cattle, and from 2 to 59% when fed on waterbuck. in waterbuck, infections were often detected through the development of parasites in tsetse at times when parasitaemia could not be detected through microscopic examination of blood. male and female, and 1- and 2-day-old ...	1991	1685299
trypanosoma congolense: re-expression of a deleted metacyclic variable antigen type in vivo and in vitro.	the expression of variable antigen types (vats) was determined among dividing populations of t. congolense growing in vivo in rabbit chancres and in vitro on bovine aorta endothelial cell monolayers. experiments were performed in which a single metacyclic vat (m-vat) was deleted from a cultured metacyclic population by neutralisation with a monoclonal antibody and complement. subsequent expression of the deleted m-vat and two unrelated m-vats was determined by an indirect immunofluorescent antib ...	1991	1685300
the effect of diminazene aceturate and isometamidium chloride on cultured procyclic forms of susceptible and drug-resistant trypanosoma congolense.	cultures of insect forms of trypanosoma congolense stocks and clones with different susceptibilities to trypanocidal drugs in vivo were initiated from bloodstream trypomastigotes harvested from mammalian hosts and maintained axenically in vitro at 27 degrees c. growth inhibition of procyclic forms of susceptible and drug-resistant t. congolense occurred after incubation for 48 h with 0.1 ng isometamidium chloride ml or 500 ng diminazene aceturate/ml. procyclic forms were propagated in vitro in t ...	1991	1685301
variability of in vitro culture characteristics, including metacyclic trypomastigote production, in different stocks of trypanosoma congolense.	six cloned stocks of trypanosoma congolense, isolated from the same area of eastern zambia, were maintained in vitro as insect form cultures producing infective metacyclic trypanosomes. although the same general culture conditions were applied, different handling regimes were required for optimum growth of each stock. during primary isolation, many differences were found in the culture characteristics of the stocks. the time taken for cytoadherence to occur varied from 14 to 62 days, while the i ...	1991	1685869
use of antigen-detection enzyme immunoassays in assessment of trypanotolerance in n'dama cattle.	antigen-detection enzyme immunoassays (elisa) were used for the diagnosis of trypanosoma vivax, t. congolense and t. brucei in n'dama cattle in gabon, central africa. the assays are based on monoclonal antibodies which recognise trypanosome antigens specific for each of the three species and animals were termed 'antigenaemic' when found positive by this technique but not found parasitaemic by the buffy coat technique. 148 one-year-old animals were exposed to a medium natural tsetse challenge and ...	1991	1686140
reduced accumulation of isometamidium by drug-resistant trypanosoma congolense.	the accumulation of the trypanocide isometamidium chloride (samorin, rmb animal health ltd., uk) by a range of clones of trypanosoma congolense with varying sensitivity to the drug, was measured by methods based on the fluorescence of isometamidium. fluorescence microscopy and flow cytometry showed a reduction in drug accumulation by resistant clones. fluorescence spectrophotometry demonstrated an inverse correlation between the intensity of cell-associated fluorescence and the level of resistan ...	1991	1745550
the role of the macrophage in induction of immunosuppression in trypanosoma congolense-infected cattle.	impairment of t-cell function in boran (bos indicus) cattle during primary infection with trypanosoma congolense ilnat 3.1 was found to occur in peripheral blood, spleen and, in particular, the lymph nodes. lymph node cells from infected cattle failed to proliferate in response to mitogenic stimulus and suppressed proliferation of both normal peripheral blood mononuclear cells and lymph node cells in co-culture assays. the addition of indomethacin, to inhibit prostaglandin synthesis, had no effe ...	1991	1748479