Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| experimental infection with a haemorrhage-causing trypanosoma vivax in n'dama and boran cattle. | n'dama cattle control experimental infections with clones of trypanosoma congolense of varying degrees of virulence, but nothing is known about their capacity to control infections caused by highly virulent, east african stocks of t. vivax. thus four n'damas and four trypanosusceptible borans were infected with a tsetse-transmitted stock of t. vivax il2337. in ayrshire cattle this stock is known to cause severe haemorrhagic disease. no differences were observed in the parasitaemia between the tw ... | 1992 | 1355307 |
| suppression of t-cell responsiveness during tsetse-transmitted trypanosomiasis in cattle. | in the present study, we demonstrate that lymph node cells from cattle infected with t. congolense through tsetse fly challenge were unable to proliferate in vitro following activation with the t-cell mitogen concanavalin a. this was associated with a simultaneous suppression of interleukin 2 (il-2) production and interleukin 2 receptor (il-2r) expression. however, the capacity of the cells to secrete interferon gamma following the mitogenic activation was not affected by the infection. | 1992 | 1355308 |
| sequential infection of tsetse flies with trypanosoma congolense and trypanosoma brucei. | the question whether tsetse flies can be experimentally infected with more than one trypanosome species or strain by sequential feeding was investigated using dna probe technology to identify directly the small numbers of trypanosomes in the fly gut. bloodstream form trypanosomes of trypanosoma congolense or t. brucei ssp. were used for initial infection, followed by sequential feeds using either t. congolense or t. brucei ssp. midgut trypanosome populations were subsequently analysed by hybridi ... | 1992 | 1356306 |
| the influence of the size of the initial inoculum on the efficacy of isometamidium (samorin) on a stock of trypanosoma congolense. | the effect of the number of trypanosomes in the initial inoculum on the minimum curative dose, was determined for an experimental infection of trypanosoma congolense in mice treated with isometamidium. mice were infected by the intravenous route and were then treated three hours later by intraperitoneal injection. the minimum curative dose was shown to be dependent on the size of the initial inoculum, with a difference of a factor of 7.5 as the initial inoculum was increased from 10(3) to 10(6) ... | 1992 | 1359748 |
| development of multiple drug resistance of trypanosoma congolense in zebu cattle under high natural tsetse fly challenge in the pastoral zone of samorogouan, burkina faso. | preliminary data from an ongoing epidemiological survey in the pastoral zone of samorogouan (kénédougou) indicate the occurrence of multiple-drug-resistant trypanosoma congolense. despite frequent trypanocidal drug treatments with diminazene aceturate (berenil, hoechst) at 7 mg/kg body weight (bw) at intervals of 2 to 4 weeks, no significant drop in the prevalence of african animal trypanosomosis (aat) was observed. to examine a suspected drug resistance, 20 zebu cattle, naturally infected with ... | 1992 | 1359750 |
| vector competence of glossina pallidipes and g. morsitans centralis for trypanosoma vivax, t. congolense and t. b. brucei. | vector competence of glossina pallidipes for pathogenic trypanosoma species was compared to that of g. morsitans centralis. cattle or goats were the hosts used to infect teneral tsetse, rabbits were used to maintain tsetse which were dissected on day 30. mean infection rates of g. pallidipes and g. m. centralis by t. vivax isolated from a cow in kenya were respectively 39.5 +/- 8.9% and 32.1 +/- 10.3% whilst for t. vivax isolated from a cow in nigeria, they were 30.0 +/- 7.5% and 19.8 +/- 4.3%. ... | 1992 | 1359753 |
| application of a monoclonal antibody-based antigen detection enzyme-linked immunosorbent assay (antigen elisa) for field diagnosis of bovine trypanosomiasis at nguruman, kenya. | a monoclonal antibody-based, enzyme immunoassay (antigen elisa) for the detection of species-specific invariant antigens of trypanosoma congolense, t. vivax or t. brucei in the serum of infected animals was evaluated as a means of diagnosis using bovine field sera from a trypanosomiasis endemic area, nguruman, kenya. circulating trypanosome antigens were detected in 126 (96.2%) of 131 serum samples from animals with parasitologically confirmed diagnosis: 74.8% were positive for antigens of two o ... | 1992 | 1360196 |
| a comparative study of gastrointestinal nematode egg output in n'dama, zebu and n'dama x zebu crossbred cattle. | strongyle faecal egg output was estimated in n'dama, zebu and n'dama x zebu crossbred (f1) cattle. n'dama cattle showed a significantly lower prevalence of strongyle infection, as measured by faecal egg output, than f1 (p < 0.01) and zebu (p < 0.001) cattle. in strongyle-infected animals, mean egg output was also significantly lower in n'damas (p < 0.03) than in zebus. a previous trypanosomiasis infection did not affect the results. the presence of a natural resistance trait to strongyle infecti ... | 1992 | 1364087 |
| in vivo assessment of drug sensitivity of african trypanosomes using the akinetoplastic induction test. | following treatment of mice infected with trypanosoma congolense or t brucei brucei with various doses of isometamidium chloride or diminazene aceturate, the induction of akinetoplastic (ak) forms was observed in the trypomastigotes of both species within 10 hours of drug administration. the levels of ak-induction were closely correlated with the levels of resistance to each compound found using a standard in vivo drug assay in mice. in general, ineffective doses of either compound conferred ak- ... | 1992 | 1374928 |
| parasite-specific t-cell responses of trypanotolerant and trypanosusceptible cattle during infection with trypanosoma congolense. | during primary tsetse-transmitted challenge of boran (bos indicus) cattle with trypanosoma congolense ilnat 3.1, a transient parasite antigen-specific t-cell proliferative response was observed in peripheral blood mononuclear cells and splenic mononuclear cells stimulated in vitro. a response was also observed with cells of n'dama (bos taurus) cattle, but in this case higher stimulation indices were observed and the response was maintained until the termination of the experiment at 40 days post- ... | 1992 | 1375583 |
| characterization and measurement of cd5+ b cells in normal and trypanosoma congolense-infected cattle. | cd5+ b cells in cattle are present in peripheral blood and spleen, but not in lymph nodes, tonsils or peyer's patches. compared to classical b cells, they express similar levels of b cell surface markers, but have higher levels of surface igm. we failed to find evidence for igd on bovine b lymphocytes. the cd5+ b cells expressed cd11b (mac-1). another small subpopulation of b cells carried cd11b but not cd5. in cattle infected with trypanosoma congolense, a dramatic increase in the percentage of ... | 1992 | 1378013 |
| trypanosoma congolense: the use of 4,6-diamidino-2-phenylindole (dapi) in the akinetoplastic induction sensitivity test. | 1992 | 1382626 | |
| pathophysiology of ovine trypanosomiasis: ferrokinetics and erythrocyte survival studies. | the haematological changes, erythrokinetics and ferrokinetics of sheep were investigated after infection with trypanosoma congolense. following the detection of parasites in blood, the infected sheep developed macrocytic hypochromic anaemia. studies with 51cr-red cells, 125i-albumin and 59fe as ferric citrate 11 weeks after infection revealed that infected sheep had significantly lower mean circulating red cell volumes but higher plasma and blood volumes than control sheep. the infected sheep al ... | 1992 | 1410823 |
| response of trypanosoma congolense in goats to single and double treatment with diminazene aceturate. | diminazene aceturate is one of a limited number of compounds currently marketed for treatment of trypanosomiasis in cattle, sheep and goats. the pharmacokinetics of the compound in goats suggest that double treatment with diminazene aceturate might enhance the compound's therapeutic activity. a study was therefore conducted in goats using two clones of trypanosoma congolense, il 3274 and il 1180, which were previously shown to be resistant and sensitive, respectively, to single treatment with di ... | 1992 | 1410826 |
| the interaction of trypanosoma congolense and haemonchus contortus infections in trypanotolerant n'dama cattle. | the interactions between trypanosoma congolense and haemonchus contortus infections were studied in n'dama calves. a total of 38 n'dama bulls was divided into four groups and each group infected either with h. contortus 1 week after infection with t. congolense or with t. congolense 4 weeks after infection with h. contortus, or with either infection singly. parasitological (faecal egg counts, parasitaemia), haematological (packed cell volume, white blood cell counts, albumin) and clinical parame ... | 1992 | 1413448 |
| [serological evidence of the existence of a wild reservoir of trypanosoma brucei gambiense in the pendjari biosphere reservation in the republic of benin]. | in the national park of pendjari, situated in the north-west of benin, 91 wild animals, belonging to seven species, were darted. thick and thin blood smears were examined for trypanosomes and plasma for trypanolytic antibodies against 6 antigenic variants of trypanosoma brucei gambiense. parasites were found in 13.92% and trypanolytic antibodies in 20.88% of the samples. a total of 28.57% of animals were positive by at least one of the two test systems used. morphologically trypanosoma congolens ... | 1992 | 1417158 |
| effect of puparia incubation temperature: increased infection rates of trypanosoma congolense in glossina morsitans centralis, g. fuscipes fuscipes and g. brevipalpis. | puparia of glossina morsitans centralis (machado), g.fuscipes fuscipes (newstead) and g.brevipalpis (newstead) were incubated at 25 +/- 1 degrees c, 28 +/- 1:25 +/- 1 degrees c, day:night or 29 +/- 1 degrees c throughout the puparial period, and maintained at 70-80% relative humidity. puparial mortality was higher at 29 than at 25 degrees c (optimum temperature) in all three species, particularly in g.f.fuscipes and g.brevipalpis. adults of g.m.centralis from puparia incubated at 29 degrees c, a ... | 1992 | 1421481 |
| a comparison of african buffalo, n'dama and boran cattle as reservoirs of trypanosoma congolense for different glossina species. | teneral glossina morsitans centralis machado were fed on the flanks of the african buffalo (syncerus caffer sparrman), n'dama (bos taurus l.) or boran (bos indicus l.) cattle infected with trypanosoma congolense broden. the infected tsetse were maintained on rabbits and on day 30 after the infected feed, the surviving tsetse were dissected to determine the infection rates. the mean infection rates (% +/- se) in the midgut of tsetse fed on buffalo, n'damas and borans were 23.5 +/- 3.3, 31.6 +/- 2 ... | 1992 | 1421502 |
| kinetic modelling of isometamidium chloride (samorin) uptake by trypanosoma congolense. | clones of trypanosoma congolense which express resistance to the widely used trypanocide isometamidium chloride accumulate less of the drug than clones which are sensitive to drug treatment. a mathematical model has been developed which was able to predict theoretical lines representing the uptake kinetics in trypanosomes which were sensitive to isometamidium, as well as for resistant trypanosomes in which reduced accumulation was a result of either reduced uptake or enhanced efflux of the drug. ... | 1992 | 1437280 |
| identification of a 33-kilodalton immunodominant antigen of trypanosoma congolense as a cysteine protease. | a 33-kda protein of trypanosoma congolense is a major antigen in infected cattle and the production of antibody to this antigen appeared to correlate with enhanced resistance to trypanosomiasis [4]. immunoelectron microscopy using a monoclonal antibody (mab 4c5) raised against the 33-kda antigen showed a lysosomal localisation, similar to that of a previously described 32-kda cysteine protease of t. congolense. both mab 4c5 and anti-33 kda antibody from infected cattle bound on western blots to ... | 1992 | 1474989 |
| the pathophysiology of ovine trypanosomosis: haematological and blood biochemical changes. | the course of trypanosoma congolense infection in sheep was followed for 96 days. infected animals developed fluctuating parasitaemia, macrocytic normochromic anaemia and leucocytosis which was principally a lymphocytosis. following treatment with the trypanocidal drug, diminazene aceturate at 84 days after infection, the haematological values returned to normal within 12 days. infected sheep developed hypocholesterolaemia and hypophospholipidaemia leading to a reduction in total serum lipids. t ... | 1992 | 1485419 |
| trypanosoma congolense: manifestation of resistance to berenil and samorin in cloned trypanosomes isolated from zambian cattle. | four trypanosoma congolense clones derived from a mumbwa field isolate proved to be resistant to berenil with a minimum curative dose (mcd) value of 40 mg/kg and to samorin with an mcd of 4 mg/kg for mice. two other clones, one being resistant to berenil with an mcd of 45 mg/kg but susceptible to 1 mg/kg samorin, and the other being resistant to samorin with mcd of 16 mg/kg but susceptible to 7 mg/kg berenil, were experimentally rendered resistant to each of the respective drugs they were suscep ... | 1992 | 1486237 |
| endocytosed transferrin in african trypanosomes is delivered to lysosomes and may not be recycled. | it has been shown in mammalian systems that the passage of transferrin-colloidal gold (tf-au) through the endocytic system is influenced by the size of the gold colloid (neutra, m. r. et al., j. histochem. cytochem. 33, 1134-1144 (1985); woods, j. w. et al., eur. j. cell biol. 50, 132-143 (1989)). however, in both trypanosoma brucei brucei and trypanosoma congolense, widely varying sizes of tf-au (tf-au5 and tf-au15) have been shown to proceed to lysosomes (webster, p., eur. j. cell biol. 49, 29 ... | 1992 | 1493805 |
| relationships between trypanosome infection measured by antigen detection enzyme immunoassays, anaemia and growth in trypanotolerant n'dama cattle. | relationships were evaluated between trypanosome infection as measured by antigen detection enzyme immunoassays (antigen elisa), anaemia as determined by average packed red cell volume (pcv), and animal performance as assessed by daily weight gain in 99 n'dama cattle in gabon exposed to natural tsetse challenge at 11.5 months of age and recorded 14 times over a 13 week period. approximately half the animals were found to be infected for an average of five of the 14 times that they were examined: ... | 1992 | 1496781 |
| trypanosome infections in warthogs (phacochoerus aethiopicus) in the gambia. | the prevalence of trypanosome infections in warthogs (phacochoerus aethiopicus) in the gambia was found to be 11% of a sample of 62 animals. all isolates were identified as trypanosoma simiae. serological evidence indicated a higher level of exposure to t. simiae, but results were inconclusive for the presence of trypanosoma congolense. the course of t. simiae infection in warthog piglets showed a rapidly rising parasitaemia, with a concomitant fall in packed cell volume, and resulted in a prolo ... | 1992 | 1502780 |
| the influence of buffalo and bovine serum on transformation of trypanosoma congolense from metacyclic forms to bloodstream forms in vitro. | the transformation of trypanosoma congolense metacyclics into bloodstream forms was studied in vitro using light and electron microscopy. the trypanosomes were maintained in culture at 28 degrees c using a medium supplemented with foetal bovine serum. the metacyclics were harvested and separated from the procyclic and epimastigote forms by using anion exchange chromatography. isolated metacyclics were incubated with different concentrations of buffalo or bovine serum at 35 degrees c for periods ... | 1992 | 1519019 |
| cloning, sequencing, and demonstration of polymorphism in trypanothione reductase from crithidia fasciculata. | trypanothione reductase (tr) is a target for drug design since it is unique to trypanosomatids, substituting for the otherwise ubiquitous enzyme, glutathione reductase. we report the cloning and sequencing of several cdnas and genes encoding crithidia fasciculata tr, the structure of which has recently been solved by crystallography. single base polymorphisms are detected in cdnas (containing 80% of the coding sequence) and two different genomic clones, including a glutamine to glutamate change ... | 1992 | 1542316 |
| suppression of interleukin 2 secretion and interleukin 2 receptor expression during tsetse-transmitted trypanosomiasis in cattle. | infection with trypanosoma congolense in cattle was found to be associated with a profound suppression of the host's immune system. lymph node cells from infected cattle were unable to secrete interleukin 2 (il 2) in vitro following mitogenic stimulation and the exogenous supply of il 2 did not restore t cell proliferative responses. this was associated with an impaired expression of the alpha chain of the il 2 receptor (il 2r alpha). co-culture experiments, where cells from an infected animal w ... | 1992 | 1547821 |
| trypanosome-induced hypothyroidism in cattle. | three boran (bos indicus) cattle infected with t. congolense il 1180, and two uninfected control boran cattle were used to study the effect of trypanosomiasis on the function of the thyroid gland. on a weekly basis, plasma thyroxine (t4) was measured by 125i-radioimmunoassay. results indicated that t. congolense caused a significant decline in plasma t4 concentration in infected animals. | 1992 | 1551017 |
| trypanosoma congolense: the in vitro akinetoplastic induction sensitivity assay. | incubation of trypanosoma congolense in diminazene aceturate (berenil) or isometamidium chloride (samorin) induced akinetoplastic (ak) forms in vitro. the ak values (expressed in percent) obtained were found to be useful for rapid assessment of relative drug sensitivities. in susceptible clones, ak forms were induced at all drug concentrations tested, whereas in resistant clones they were induced only at higher concentrations. the berenil-resistant clone exhibited ak values of 0.9% +/- 0.6%--8.9 ... | 1992 | 1557326 |
| cell surface interactions between trypanosoma congolense and macrophages during phagocytosis in vitro. | trypanosoma congolense bloodstream forms preincubated with a high titer of anti-variant surface antigen (vsg)-specific antibody, a low amount of anti-vsg plus complement-active mouse serum (ms), ms alone, and trypsin were cocultivated with mouse peritoneal macrophages in vitro. immunofluorescence as well as transmission and scanning electron microscopy revealed that upon attachment to the macrophages' surface, trypanosomes opsonized with anti-vsg/ms formed opsonized filopodia, which were rapidly ... | 1992 | 1560418 |
| metacyclic form-specific variable surface glycoprotein-encoding genes of trypanosoma (nannomonas) congolense. | a complementary dna expression library in phage lambda gt11 was synthesized using mrna from in vitro-produced metacyclic forms of a clone of trypanosoma (nannomonas) congolense. the unamplified library was screened with antiserum from a goat immune to infection with metacyclic (m)-forms of t. congolense ilrad nannomonas antigen repertoire 2(ilnar2). of the 100 antiserum-reactive phage clones identified, 22 were analyzed further: 21 of the clones contained overlapping portions of a single transcr ... | 1992 | 1572537 |
| identification and characterization of two repetitive non-variable antigens from african trypanosomes which are recognized early during infection. | the present paper describes two repetitive proteins representing common antigens of african trypanosomes which are non-variant and which are recognized early in infection by the host immune system. these antigens were identified by their ability to immunoreact with bovine serum taken during the early phase of a cyclic trypanosomal infection. screening of a cdna library from t. b. gambiense with such early infection serum identified a protein which contains a repetitive motif consisting of 68 ami ... | 1992 | 1614728 |
| adrenal and thyroid dysfunctions in experimental trypanosoma congolense infection in cattle. | severe pathological changes were observed in the adrenal and thyroid glands of zebu (bos indicus) heifers infected with trypanosoma congolense. in the adrenal glands, severe inflammatory changes characterised by mononuclear cellular infiltration in the subcapsular areas, zona glomerulosa, zona fasciculata and zona reticularis were observed. in addition, there were hyperaemia, haemorrhage and hyperplasia resulting in increased adrenal weight in the two heifers slaughtered on days 50 and 70 post-i ... | 1992 | 1615626 |
| comparative studies on n'dama and zebu cattle following repeated infections with trypanosoma congolense. | twenty n'dama and eight zebu cattle were inoculated intradermally with bloodstream forms of a cloned strain of trypanosoma congolense originating from east africa. all inoculated cattle became parasitaemic. zebus showed consistently higher levels of parasitaemia and lower packed red cell volume (pcv) percentages than did n'damas. three of the eight zebus required treatment when high numbers of trypanosomes were present in the blood and pcv values dropped below 15 per cent. none of the n'dama cat ... | 1992 | 1620961 |
| kinetic isotope effect analysis of the reaction catalyzed by trypanosoma congolense trypanothione reductase. | african trypanosomes are devoid of glutathione reductase activity, and instead contain a unique flavoprotein variant, trypanothione reductase, which acts on a cyclic derivative of glutathione, trypanothione. the high degree of sequence similarity between trypanothione reductase and glutathione reductase, as well as the obvious similarity in the reactions catalyzed, led us to investigate the ph dependence of the kinetic parameters, and the isotopic behavior of trypanothione reductase. the ph depe ... | 1992 | 1633154 |
| transport of isometamidium (samorin) by drug-resistant and drug-sensitive trypanosoma congolense. | the uptake kinetics of a 14c-labelled trypanocidal compound isometamidium chloride (samorin, rmb animal health ltd, uk) was measured in drug-resistant and drug-sensitive trypanosoma congolense. it was established that drug uptake was significantly more rapid and quantitatively greater in drug-sensitive parasites. there was clear evidence that drug uptake in both the resistant and sensitive trypanosomes was by a specific, receptor-mediated process. this specific drug transport was energy-dependen ... | 1992 | 1641246 |
| characterisation of a cysteine protease from bloodstream forms of trypanosoma congolense. | a cysteine protease (trypanopain-tc) with cathepsin-l-like properties has been purified from trypanosoma congolense. the enzyme has an apparent molecular mass of 31-32 kda by sds/page and 66 kda by gel chromatography. it has a pi 7.4 and a high affinity for concanavalin a. trypanopain-tc catalyses the limited proteolysis of a variety of protein substrates such as fibrinogen, serum albumin and trypanosome variant-surface glycoprotein. it has minimal or no activity against casein or elastin. a var ... | 1992 | 1740149 |
| 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 |
| porcine trypanosomosis in nigeria: infections in local and exotic pigs in the nsukka area of anambra state. | a twelve-month survey in three local government areas (lga) in nsukka zone, anambra state, nigeria revealed that out of 150 local and exotic breeds of pig examined, 46 (30.7%) were infected with trypanosomes. both single and mixed infections of trypanosoma brucei and t. congolense were observed. however, t. brucei was the predominant trypanosome encountered. the husbandry system in practice was the most significant factor influencing the prevalence of trypanosomes in the pigs. in addition signif ... | 1991 | 1763434 |
| trypanosomiasis in different breeds of cattle from benin. | blood of different breeds of cattle, namely lagune from the atlantic province, borgou and borgou x zebu from the borgou province, and somba and zebu from the atacora province of benin, were examined for trypanosome infection. thick and thin blood smears for trypanosomes, the card agglutination test (catt), indirect immunofluorescent antibody test (ifat) and trypanolytic test for antibodies to trypanosomes were used. trypanosomes were detected in 19.3% (range 9.8-31.4%) of animals by examination ... | 1991 | 1763478 |
| an outbreak of trypanosomosis on the jos plateau, nigeria. | 1991 | 1796524 | |
| immunolocalization of a cysteine protease within the lysosomal system of trypanosoma congolense. | a cysteine protease has been purified from bloodstream forms of trypanosoma congolense by affinity chromatography on cystatin-sepharose. a polyclonal antibody was raised against the purified enzyme and used for immunocytochemical localization of the enzyme by electron microscopy. antibody labeling of the cysteine protease, using colloidal gold-labeled protein a (pra-au), was observed over amorphous material within subcellular organelles which have the appearance of lysosome-like bodies. this int ... | 1991 | 1802711 |
| pig trypanosomiasis: comparative anaemia and histopathology of lymphoid organs. | anaemia with characteristic clinical symptoms, haematological changes and histopathology of lymphoid organs, was observed following experimental infection of pig with pathogenic species of trypanosoma brucei brucei and trypanosoma congolense, the former being more virulent than the latter. mean incubation periods were 4 and 7 days, and generalized fluctuating levels of parasitaemia and pyrexia without mortality were observed. other symptoms included hyperaemia, petechial haemorrhages leading to ... | 1991 | 1824133 |
| plasma levels of proteins of the alternative complement pathway in inbred mice that differ in resistance to trypanosoma congolense infections. | inbred balb/c, a/j, and c57b1/6j mice were infected with trypanosoma congolense (trans mara strain), clone tc13, and monitored for parasitemia, survival times, and plasma levels of complement components c3, c5, factor b, and factor h. parasitemia was highest in balb/c, intermediate in a/j, and lowest in c57bl/6j mice. the mean survival times were 11.5 +/- 0.9, 23.8 +/- 2.3, and 119 +/- 26 days for balb/c, a/j, and c57bl/6j mice, respectively. preinfection levels of factor h were significantly co ... | 1991 | 1838113 |
| comparative study on rickettsia-like organisms in the midgut epithelial cells of different glossina species. | the midgut epithelium of glossina morsitans centralis, g. austeni, g. pallidipes, g. palpalis palpalis, g. p. gambiensis, g. fuscipes fuscipes, g. tachinoides and g. brevipalpis from ilrad-bred colonies was examined, by electron microscopy, for the presence and distribution of rickettsia-like organisms (rlos). rlos were present in the midgut epithelial cells of all non-teneral tsetse. in g.m. centralis, g. pallidipes and, to a much lesser extent, g. brevipalpis, rlos were numerous and were prese ... | 1991 | 1852486 |
| rickettsia-like organisms, puparial temperature and susceptibility to trypanosome infection in glossina morsitans. | maintaining the puparial stage of successive generations of a population of tsetse 3 degrees c lower than normal reduced the numbers of rickettsia-like organisms (rlo) carried by emerging flies. the susceptibility of these flies to midgut infection with trypanosoma congolense was also significantly reduced compared with control flies held at normal temperature. these results support the view that the relationship between rlo and susceptibility is quantitative-teneral flies with heavier rlo infec ... | 1991 | 1852487 |
| in vitro cultivation of trypanosoma congolense bloodstream forms in the absence of feeder cell layers. | bloodstream forms of trypanosoma congolense (2 clones: ilnat3.1 and il3000, and 4 stocks: il2079, il2466, il3266 and cp-81) were continuously cultivated in vitro at 34-36 degrees c in the absence of feeder cell layers, using hmi-93 medium which was modified from iscove's modified dulbecco's mem (flow laboratories, irvine, scotland). the modification was done by supplementing the medium with 0.05 mm bathocuproine sulphonate, 1.5 mm l-cysteine, 0.5 mm hypoxanthine, 0.12 mm 2-mercaptoethanol, 1 mm ... | 1991 | 1852490 |
| in vitro drug sensitivity of trypanosoma congolense isolates. | the sensitivity of trypanosoma congolense isolates to diminazene and isometamidium was determined using an incorporation assay based on the uptake of [3h]-hypoxanthine in the presence of serial drug dilutions. the bloodstream forms of the different isolates exhibited variation in their sensitivity to the drugs that correlated well with the in vivo drug response. for diminazene, the sensitivity of the most sensitive population was 40 times that of the least sensitive population. for isometamidium ... | 1991 | 1866422 |
| diminazene aceturate residues in the tissues of healthy, trypanosoma congolense and trypanosoma brucei brucei infected dogs. | the tissue distribution and residue profile of diminazene aceturate was investigated in healthy dogs and in dogs infected with trypanosoma congolense and trypanosoma brucei brucei. the drug was administered at 3.5 mg/kg i.m. and tissue samples were taken post mortem from the animals at 48, 72, 120, 168 and 240 h after injection. the drug was distributed to various organs and tissues of the body with the highest concentrations occurring in liver and kidney. higher drug levels were obtained in the ... | 1991 | 1868320 |
| elusive trypanosomes. | professor kershaw's encouragement of the development of anion-exchange separation of african trypanosomes from blood led to two decades of activity when, for the first time, considerable progress was made in the intrinsic characterization of these parasites. such characterization depended on establishing high infections in laboratory rodents. however, the collection of samples from the field was restricted by the failure of certain trypanosomes either to infect, or to multiply adequately in, rod ... | 1991 | 1888216 |
| effect of isometamidium on trypanosoma congolense infectivity. | isometamidium chloride (samorin, rmb, england) is a widely used and highly effective trypanocide for the treatment of bovine trypanosomiases. however, the appearance of isometamidium-resistant populations of t. congolense in africa makes it necessary to develop methods for the rapid and reliable detection of drug resistance in the laboratory. currently available tests are time-consuming and/or expensive. in the present study, the short-term in vitro incubation of trypanosomes in a range of isome ... | 1991 | 1897115 |
| therapeutic effect of berenil and samorin in mice infected with four trypanosome populations isolated from zambian cattle. | four populations of trypanosoma congolense and trypanosoma brucei brucei were isolated from cattle under different management practices and environments in zambia. all four isolates had varied responses to both diminazene aceturate (berenil) and isometamidium chloride (samorin) as curative drugs in infected mice. trypanosomes from a traditionally managed herd in a high-tsetse-challenge area had the strains most resistant to berenil, with maximum curative dose of 45 mg kg-1 body weight. another i ... | 1991 | 1897118 |
| susceptibility of n'dama and boran cattle to tsetse-transmitted primary and rechallenge infections with a homologous serodeme of trypanosoma congolense. | eight trypanotolerant n'dama cattle controlled an infection of trypanosoma congolense ilnat 3.1 transmitted by glossina morsitans centralis, more efficiently than a group of similarly infected trypanosusceptible boran cattle. all eight n'damas maintained their pcv above 15% throughout the primary infection whereas the pcv of six of the eight borans dropped below 15%; these latter animals were treated with diminazene aceturate to prevent possible death. lymphocyte, neutrophil and platelet counts ... | 1991 | 1923566 |
| susceptibility of n'dama and boran cattle to sequential challenges with tsetse-transmitted clones of trypanosoma congolense. | the susceptibility of n'dama cattle (bos taurus) to four consecutive infections with different tsetse-transmitted clones of trypanosoma congolense was compared with that of borans (bos indicus). all animals were aged 13 months at the start of the study and had been born and raised free from trypanosomiasis under the same management and nutritional conditions, thereby limiting environmental factors that could have influenced susceptibility. while cattle of both breeds were equally susceptible to ... | 1991 | 1923567 |
| engineering the substrate specificity of glutathione reductase toward that of trypanothione reduction. | glutathione reductase (ec 1.6.4.2; cas registry number 9001-48-3) and trypanothione reductase (cas registry number 102210-35-5), which are related flavoprotein disulfide oxidoreductases, have marked specificities for glutathione and trypanothione, respectively. a combination of primary sequence alignments and molecular modeling, together with the high-resolution crystal structure of human glutathione reductase, identified certain residues as potentially being responsible for substrate discrimina ... | 1991 | 1924337 |
| [interpretation of the catt (card agglutination trypanosomiasis test) in the screening for human trypanosomiasis due to trypanosoma brucei gambiense]. | mass screening for gambiense sleeping sickness is usually done with the card agglutination trypanosomiasis test (catt) in series (total blood catt followed by a serum catt if the first test is positive) and the search for trypanosomes in cervical adenopathies. at present, the double positives (blood catt and serum catt) as well as the subjects in whom the trypanosome was found (in the blood or gland juice) are treated. the existence of patients whose gland punction was proved positive whereas th ... | 1991 | 1958107 |
| [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 |
| 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 |
| analysis of peripheral leucocyte populations in n'dama and boran cattle following a rechallenge infection with trypanosoma congolense. | monoclonal antibodies, flow cytometry and routine haematological techniques were used to analyse circulating leucocyte populations in trypanotolerant (n'dama) and trypanosusceptible (boran) cattle following a homologous rechallenge with trypanosoma congolense clone il13-e3. the n'damas developed a low, transient parasitaemia and did not develop anaemia. the borans became parasitaemic and developed chronic anaemia but three of the five animals eventually self-cured, whilst, a group of primary-cha ... | 1991 | 1711196 |
| immunohistology of lymph nodes draining local skin reactions (chancres) in sheep infected with trypanosoma congolense. | marked enlargement of lymph nodes draining local skin reactions (chancres) occurred in sheep following intradermal inoculation of cultured metacyclic forms of trypanosoma congolense. histologically, these lymph nodes were characterized by follicular hypertrophy and hyperplasia, compression and relative reduction of the paracortical areas and expansion of the medullary regions. immunohistochemical staining with monoclonal antibodies to ovine lymphocyte subsets and fc receptor (fcr) bearing macrop ... | 1991 | 1717523 |
| trypanosoma (nannomonas) congolense: changes in respiratory metabolism during the life cycle. | all four life cycle stages (bloodstream, procyclic, epimastigote, and metacyclic) of trypanosoma congolense il 3000 were assayed with an oxygen electrode (polarograph) for the presence of terminal oxidases and carbon-source preference. in addition, these stages were used for histochemical analysis of mitochondrial activity using rhodamine 123, nitroblue tetrazolium, and diaminobenzidine. morphometry was used to compare mitochondrial volumes and surface area among the different life cycle stages. ... | 1991 | 1720394 |
| 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 |