| relationships between protease activity, host blood and infection rates in glossina morsitans sspp. infected with trypanosoma congolense, t. brucei and t. simiae. | midgut protease activity in glossina morsitans centralis and g.m. morsitans, at 48 h post bloodmeal averaged 1.8iu of trypsin-like activity. these two tsetse subspecies differ in their susceptibility to trypanosome infection. except for low levels in flies fed on waterbuck blood (0.7 iu), activity did not differ in flies fed a variety of host bloods (goat, pig, cow, buffalo, eland) and trypanosome species (trypanosoma congolense, t. brucei, t. simiae). protease activity was also not correlated w ... | 1994 | 8161844 |
| midgut lectin activity and sugar specificity in teneral and fed tsetse. | midgut infection rates of trypanosoma congolense in glossina palpalis palpalis and of trypanosoma brucei rhodesiense in glossina pallidipes are potentiated by the addition of d+ glucosamine to the infective feed, but not to the levels of super-infection reported for g.m.morsitans, g.p.palpalis and g.pallidipes are shown to possess two trypanocidal molecules: a glucosyl lectin which can be inhibited by d+ glucosamine and a galactosyl molecule inhibited by d+ galactose. addition of both d+ glucosa ... | 1994 | 8161852 |
| a comparison of the susceptibility of djallonké sheep and west african dwarf goats to experimental infection with two different strains of trypanosoma congolense. | two cloned strains of trypanosoma congolense, of west and east african origin, were used to infect by intradermal inoculation two groups of young adult female djallonké sheep and west african dwarf goats. for a 3 month period post-infection, packed red cell volume (pcv), parasitaemia, body weight and clinical parameters were followed to evaluate their trypanotolerant nature and to control the pathogenicity of the two strains of t. congolense. although the west african strain of t. congolense was ... | 1994 | 8171821 |
| effects of trypanosoma congolense infection on the pituitary gland of baoulé bulls: immunohistochemistry of lh- and fsh-secreting cells and response of plasma lh and testosterone to combined dexamethasone and gnrh treatment. | the effects of trypanosoma congolense infection were investigated at the pituitary level on trypanosome resistant baoulé bulls (aged 3-6 years), using immunohistochemistry of lh- and fsh-secreting cells and a combined dexamethasone and gnrh challenge. the pituitaries of two control and five naturally infected baoulé bulls were removed after slaughter and the lh- and fsh-secreting cells were examined immunohistochemically, using specific polyclonal antibodies against beta lh and beta fsh. no sign ... | 1994 | 8182584 |
| relapse of trypanosoma congolense infection in goats after diminazene aceturate is not a result of invasion of the central nervous system. | | 1994 | 8192521 |
| isometamidium concentrations in the sera of boran cattle: correlation with prophylaxis against tsetse-transmitted trypanosoma congolense. | fifteen boran cattle from a trypanosomiasis-free area were injected intramuscularly with isometamidium chloride at a dose of 1 mg/kg body weight. thereafter, the cattle were challenged at monthly intervals with glossina morsitans centralis infected with one of three populations of trypanosoma congolense (il 3893, il 3889 or il 1180) until all animals became infected. isometamidium concentrations in the sera of these cattle were measured using a competitive enzyme-linked immunosorbent assay over ... | 1994 | 8203294 |
| major surface glycoproteins of procyclic stage african trypanosomes. | the procyclic stage in the life cycle of african trypanosomes is adapted for life in the harsh environment of the midgut of the tsetse fly vector. procyclic forms derived by transformation from antigenically distinct bloodstream variants are antigenically similar and have lost the variant surface glycoprotein coat of the bloodstream forms. in contrast to bloodstream forms, where the variant surface glycoprotein coat is essentially the only molecule exposed, many different proteins can be labeled ... | 1994 | 8206145 |
| conservation of grna gene cassette structure in african trypanosomes despite divergence in the defining flanking repeats. | | 1993 | 8232424 |
| sequences of three trypanosoma congolense maxicircle genes allow prediction of regions encoding transcripts that undergo extensive rna editing. | | 1993 | 8232425 |
| antibody responses to a 33 kda cysteine protease of trypanosoma congolense: relationship to 'trypanotolerance' in cattle. | a cysteine protease of trypanosoma congolense (congopain) elicited igg1 antibodies in those cattle which exhibited a degree of resistance to disease during experimental infections (authié et al. 1992, 1993). the aim of the present study was to investigate further the association between anti-congopain antibodies and resistance to trypanosomiasis, and to provide a lead into the mechanisms responsible for the differential responses to congopain in cattle. isotype characteristics and kinetics of th ... | 1993 | 8233561 |
| secretion of co-stimulatory cytokines by monocytes and macrophages during infection with trypanosoma (nannomonas) congolense in susceptible and tolerant cattle. | bovine macrophages and monocytes were cultured in vitro and analyzed for their capacity to secrete co-stimulatory cytokines. to this end, the culture medium was titrated on suboptimally stimulated murine thymocytes. a low residual release by normal monocytes was noted which usually remained below the detection limit of the assay. these cells could be induced to secrete high titres following activation with bacterial lipopolysaccharide. when harvested from animals infected with trypanosoma congol ... | 1993 | 8236792 |
| the prevalence of concurrent trypanosome and gastrointestinal nematode infections in west african dwarf sheep and goats in nsukka area of eastern nigeria. | the prevalence of concurrent nematode-trypanosome infections in traditionally reared west african dwarf sheep and goats in eastern nigeria was monitored over a 12-month period during 1987-1988. the most prevalent nematodes were haemonchus contortus and trichostrongylus colubriformis, which usually occurred together in all nematode infected animals. their combined prevalence rates ranged from 90 to 100% throughout the year and they accounted for 66 to 98% of the total monthly worm burdens. of the ... | 1993 | 8249254 |
| immune lysis of trypanosoma congolense: generation of a soluble covalent complex of variant surface glycoprotein and bovine complement component c3b. | organisms of trypanosoma congolense variant antigenic type tc13 (vat tc13) were incubated, at 37 degrees c for 60 min, with fresh bovine serum in the presence of antibody specific for the variant surface glycoprotein (vsg). upon immune lysis, soluble vsg (54 kda) and a larger complex (about 225 kda), containing vsg, was detected in the supernatant fluid of the mixture. neither soluble vsg nor the vsg complex were detected when fresh bovine serum was incubated with organisms of t. congolense in t ... | 1993 | 8256435 |
| a major surface antigen of procyclic stage trypanosoma congolense. | five monoclonal antibodies (mab) were raised that bound to the surface of procyclic stage trypanosoma congolense with high intensity in immunofluorescence. immunoblot analysis of trypanosome lysates using 3 of these mab revealed a diffuse sds-page band of 36-40 kda. the purified antigen did not react with coomassie blue or silver stains, but did stain blue with stains-all, indicating acidity. for the one mab tested, the epitope was periodate-sensitive and therefore probably glycan. although this ... | 1993 | 8264732 |
| trypanosoma congolense in the microvasculature of the pituitary gland of experimentally infected boran cattle (bos indicus). | the pituitary glands of seven boran cattle (bos indicus), five infected with a clone of trypanosoma congolense il 1180 (ilnat 3.1) transmitted by glossina morsitans centralis and two uninfected controls, were examined by light and electron microscopy 43 (experiment 2) or 56 (experiment 1) days after fly challenge. the three cattle used in the first experiment included a 15-month-old female (no. 1), a 24-month-old female (no. 2), and a 21-month-old male (no. 3) as a control. in the second experim ... | 1993 | 8266622 |
| a comparison of susceptibility of two allopatric populations of glossina pallidipes for stocks of trypanosoma congolense. | a colony of glossina pallidipes austen which originated from nguruman, rift valley province, kenya, was significantly more susceptible to infection (19.3%) with a stock of trypanosoma congolense broden isolated from g. pallidipes in nguruman than a colony of the same species which originated from shimba hills, coast province, kenya (5.6%). male g.pallidipes from nguruman were significantly more susceptible than females to this t.congolense stock whilst the susceptibility of both sexes of g.palli ... | 1993 | 8268493 |
| variation in sensitivity of trypanosoma congolense to diminazene during the early phase of tsetse-transmitted infection in goats. | twenty-five goats were randomly allocated to five groups of five animals each and infected with trypanosoma congolense il 3274 via the bites of infected glossina morsitans centralis. at intervals of 1, 4, 8, 12 or 19 days following infection, each group of five animals was treated intramuscularly with diminazene aceturate at a dose of 7.0 mg kg-1 body weight (b.w.). while treatment on day 1 eliminated infections in all five goats, treatment on day 19 did not cure any of the animals; in groups tr ... | 1993 | 8291183 |
| a colorimetric assay for trypanosome viability and metabolic function. | we have adapted a tetrazolium salt (mtt) colorimetric cytotoxicity assay to the assessment of viability and metabolic function in cultured african trypanosomes. trypomastigotes of trypanosoma congolense and t. brucei rhodesianse were harvested from the blood of parasitemic rats and cultured under axenic conditions that support trypanosome viability and growth. analysis of serial dilutions of these bloodstream forms indicated that the assay could detect 10(4) parasites. to assess the effect of ly ... | 1993 | 8291189 |
| evaluation of the efficacy of a slow release device containing homidium bromide in rabbits infected with trypanosoma congolense. | the subcutaneous implantation of a slow release device (srd) containing 1 mg kg-1 homidium bromide (ethidium) protected 95% of the rabbits for at least 3 months against reinfection with different stocks of trypanosoma congolense. only 30.8% of the animals, which received the classical intramuscular injection of 1 mg kg-1 homidium bromide, were protected for more than 1 month. the advantages of an srd against injection of homidium bromide are a longer protection period, less variation in the perc ... | 1993 | 8291190 |
| the effect of cattle infection by trypanosoma congolense on the attraction, and feeding success, of the tsetse fly glossina pallidipes. | an incomplete ring of electric nets was placed around uninfected cattle and cattle infected with trypanosoma congolense. the numbers of fed and unfed glossina pallidipes caught on the nets were used to estimate the attractiveness of infected and uninfected cattle to tsetse, and the feeding success of tsetse on the cattle. there was no difference in the attractiveness of infected and uninfected cattle to g. pallidipes. however, the feeding success of g. pallidipes on infected cattle was 75% great ... | 1993 | 8316432 |
| phospholipase a2 from trypanosoma congolense: characterization and haematological properties. | phospholipase a2 was isolated from trypanosoma congolense and purified to electrophoretic homogeneity. the enzyme appeared to exist in a dimeric form with subunit molecular weights of 16,500 and 18,000. it had a ph optimum of 6.8. kinetic analysis with different substrates, showed that the enzyme had exceptional specificity for 1,2,dimyristoyl-sn-phosphatidylcholine and 1,2,dioleoyl-sn-phosphatidylcholine with km values of 1.85 x 10(-3) m and 2.12 x 10(-3) m respectively. the arrhenius plot was ... | 1993 | 8324881 |
| susceptibility of nigerian west african dwarf and red sokoto goats to a strain of trypanosoma congolense. | west african dwarf (wad) and red sokoto (rs) goats were experimentally infected with the kafanchan strain of trypanosoma congolense and the course of the infection was monitored. the organism was pathogenic and produced fatal disease in the goats, which was characterized by rapid progressive anaemia, leucocytosis, weight loss and death. all rs goats died within 11 days of infection, and had a mean reduction in packed cell volume (pcv) of 11%. in west african dwarf goats, one death occurred on da ... | 1993 | 8333125 |
| the pathophysiology of trypanosoma congolense infection in scottish blackface sheep. influence of dietary protein. | the intensity of parasitaemia, degree of anaemia, blood biochemical changes and live weight gains were measured in two groups of scottish blackface sheep infected experimentally with bloodstream forms of trypanosoma congolense and given either a high or a low protein diet. it was observed that infected animals on a high protein diet tended to develop a higher intensity of parasitaemia than those on a low protein diet. both groups of infected sheep exhibited similar degrees of anaemia, but the er ... | 1993 | 8333126 |
| epidemiology of trypanosome infections of the tsetse fly glossina pallidipes in the zambezi valley. | the epidemiology of trypanosome infections of glossina pallidipes was studied at a riverine site in the zambezi valley, zimbabwe for a period of 13 months. over 9000 flies were captured using a single trap. these flies were dissected, screened for trypanosome infection, sexed, and aged using both wing fray and (for females) ovarian category indices. midgut infections were identified to species using recently developed dna probes. the overall prevalence of mature infections was 5.5%, comprising 3 ... | 1993 | 8341584 |
| the influence of host blood on infection rates in glossina morsitans sspp. infected with trypanosoma congolense, t. brucei and t. simiae. | trypanosoma congolense, t. brucei and t. simiae isolated from wild-caught glossina pallidipes were fed to laboratory-reared g. morsitans centralis and g.m. morsitans to determine the effect of host blood at the time of the infective feed on infection rates. bloodstream forms of trypanosomes were membrane-fed to flies either neat, or mixed with blood from cows, goats, pigs, buffalo, eland, waterbuck and oryx. the use of different bloods for the infective feed resulted in differences in infection ... | 1993 | 8355996 |
| pathogenesis and pathology of african trypanosomosis in baoulé, n'dama/baoulé cross bred and zebu cattle in burkina faso. 1. clinical performance under high natural tsetse challenge. | the pathogenesis and pathology of african animal trypanosomosis (aat) in baoulé, n'dama/baoulé-cross-bred and zebu cattle was studied from 1987 to 1991 in a series of experiments conducted under natural and artificial conditions of challenge at the centre de recherches sur les trypanosomoses animales (crta) in burkina faso. this first paper reports on the clinical performance of 64 baoulé, 10 n'dama/baoulé-cross-bred and 20 zebu cattle, which were transferred to the pastoral zone of satiri, 50 k ... | 1993 | 8367674 |
| trypanosoma (nannomonas) congolense: molecular characterization of a new genotype from tsavo, kenya. | trypanosoma (nannomonas) congolense comprises morphologically identical but genetically heterogeneous parasites infective to livestock and other mammalian hosts; three different genotypes of this parasite have been described previously. restriction enzyme fragment length polymorphisms (rflps) in both kinetoplast dna minicircle and nuclear dna sequences, and randomly amplified polymorphic deoxyribonucleic acid (rapd) patterns have been used here to demonstrate the existence of another type of t. ... | 1993 | 8383313 |
| reduced responsiveness of the hypothalamic-pituitary-adrenal axis in boran (bos inducus) cattle infected with trypanosoma congolense. | the response of the pituitary-adrenal axis to corticotrophin-releasing hormone (crh) and the adrenal response to adrenocorticotrophin hormone (acth) stimulation were studied during infection of boran (bos indicus) cattle with trypanosoma congolense. for crh, 15 animals were challenged during preinfection and infection phases, while for acth 10 animals were challenged during pre-infection, infection and post-treatment phases of the experiments. the axis showed a reduced responsiveness after crh c ... | 1993 | 8394613 |
| maxicircle dna and edited mrna sequences of closely related trypanosome species: implications of krna editing for evolution of maxicircle genomes. | krna editing produces functional mrnas by uridine insertion and deletion. we analyzed portions of the apocytochrome b and nadh dehydrogenase subunits 7 and 8 (nd7 and 8) genes and their edited mrnas in trypanosoma congolense and compared these to the corresponding sequences in t.brucei. we find that these genes are highly diverged between the two species, especially in the positions of thymidines and in nucleotide transitions. editing eliminates differences in encoded uridines producing edited m ... | 1993 | 8396763 |
| rickettsia-like organisms and chitinase production in relation to transmission of trypanosomes by tsetse flies. | rickettsia-like organisms (rlo) from testse midguts and mosquito cell cultures showed high levels of endochitinase activity. a line of glossina morsitans morsitans highly susceptible to midgut trypanosome infection and with high incidence of rlo infection showed significantly greater chitinolytic activity than g. austeni which had low rlo incidence and were correspondingly refractory to midgut infection. midgut infection rates of trypanosoma brucei rhodesiense in g. m. morsitans showed a dose-re ... | 1993 | 8414668 |
| antibody responses to invariant antigens of trypanosoma congolense in cattle of differing susceptibility to trypanosomiasis. | five trypanotolerant n'dama (bos taurus) and five susceptible boran (bos indicus) cattle were challenged by tsetse flies infected with trypanosoma congolense il 13-e3. these animals had experienced five previous infections with t. congolense, each terminated by drug therapy. immunoblotting and elisa were used to determine isotype and specificity of antibody responses to trypanosome invariant antigens. both igm and igg1 were elicited, but the igg1 responses were directed against a greater diversi ... | 1993 | 8446463 |
| measurement of trypanotolerance criteria and their effect on reproductive performance of n'dama cattle. | one thousand and twenty-eight cow-year records were available from 260 n'dama cows each having at least 2 years of monthly matching health and performance data over a 5-year period under a medium natural tsetse challenge in gabon. four hundred and fifty-eight calf/dam pairs were also available where the calf had been reared to weaning, both had monthly matching records and each cow had weaned at least two calves. evaluations were carried out on effects of, and linkages between, environmental and ... | 1993 | 8447067 |
| trypanosoma congolense: in vitro susceptibility of bloodstream forms to diminazene and isometamidium. | | 1993 | 8454031 |
| fluorescence analysis of the interaction of isometamidium with trypanosoma congolense. | isometamidium chloride (samorin) is the only compound recommended for prophylaxis against bovine trypanosomiasis in sub-saharan africa. the fluorescence property of this compound was used to investigate the interaction of the molecule with in vitro-derived bloodstream forms of trypanosoma congolense il 1180. incubation of isometamidium with trypanosomes at 37 degrees c for 180 min resulted in a gradual alteration of the lambda max. with time (from 600 to 584 nm) and an increase in the intensity ... | 1993 | 8503859 |
| defecation by anopheles arabiensis mosquitoes of host blood infected with live trypanosoma congolense. | female anopheles arabiensis mosquitoes were experimentally fed on hamsters and balb/c mice which were either clean or infected with trypanosoma congolense. the mosquitoes readily fed on either animal. a blood repletion rate of 82.7% was recorded for mosquitoes feeding on hamsters. seventy seven per cent of the replete mosquitoes continued to feed while at the same time defecating the host's blood in droplets, ejected in quick succession from the anus. ninety five per cent of mosquitoes defecatin ... | 1993 | 8516628 |
| derivation and characterization of a quinapyramine-resistant clone of trypanosoma congolense. | over a period of 208 days a quinapyramine-resistant population was derived in vivo from a quinapyramine-susceptible clone of trypanosoma congolense: il 1180. while the dose of quinapyramine sulfate required to cure 50% of mice infected with the parental clone was 0.23 mg/kg of body weight, the 50% curative dose for the resistant derivative, il 1180/stabilate 12, was greater than 9.6 mg/kg. this approximately 40-fold increase in resistance to quinapyramine was shown to be associated with an 8-fol ... | 1993 | 8517707 |
| mechanical transmission of trypanosoma spp. by african stomoxyinae (diptera: muscidae). | ten taxa of stomoxyinae were tested for their ability to transmit trypanosoma brucei, t. vivax, t. evansi and t. congolense to mice within 3 min of interrupted feeding on highly parasitaemic blood. t. brucei was the easiest parasite to transmit with an 11.5% success rate, followed by t. vivax at 3.4%, and t. evansi at 0.9%. t. congolense was not transmitted in 129 attempts. stomoxys niger sspp. and four unstudied species (s. varipes, s. taeniatus, s. pallidus, haematobosca squalida) were capable ... | 1995 | 8525279 |
| successful application of deltamethrin pour on to cattle in a campaign against tsetse flies (glossina spp.) in the pastoral zone of samorogouan, burkina faso. | 1,500-2,000 head of cattle were treated with deltamethrin 1% spot on in an area of high tsetse densities, notably of glossina morsitans submorsitans. after four treatments at monthly intervals, the time between two treatments was increased to two months. 11 months after the commencement of the campaign the fly population had decreased from initially 54.2 flies/trap/day to densities varying between 0.06-2.0 flies/trap/day, mostly g. palpalis gambiensis. blood-meal analysis showed that this specie ... | 1995 | 8533022 |
| the influence of energy intake on the pathophysiology of trypanosoma congolense infection in scottish blackface sheep. | the intensity of parasitaemia, degree of anaemia, live body weight gains and blood biochemical changes were measured in two groups of scottish blackface sheep infected experimentally with trypanosoma congolense and allowed either a high (9.9 mj metabolisable energy (me) day-1) or a low (6.1 mj me day-1) energy intake. it was observed that infected animals on the low energy intake had a longer mean prepatent period, but following patency they developed more severe anaemia and greater growth retar ... | 1995 | 8533279 |
| a comparison of glossina morsitans centralis originating from tanzania and zambia, with respect to vectorial competence for pathogenic trypanosoma species, genetic variation and inter-colony fertility. | two laboratory strains of glossina morsitans centralis originating from different fly-belts (one from singida, in tanzania, and the other from mumbwa, in zambia) were compared with respect to vectorial competence for pathogenic trypanosoma species, genetic variation and inter-colony fertility. the vectorial competence of g.m.centralis of tanzanian origin for trypanosma vivax and t. congolense is similar to, whereas for t.brucei brucei it is lower than the colony of zambian origin. nevertheless, ... | 1995 | 8541585 |
| genetics of resistance to trypanosoma congolense in inbred mice: efficiency of apparent clearance of parasites correlates with long-term survival. | to study the genetic parameters of resistance to trypanosoma congolense infection, highly susceptible balb/c and relatively resistant c57bl/6 mice were crossed to produce reciprocal f1 and f2 offspring. mice were infected with t. congolense and monitored for parasitemia within the first 2 wk and also for their survival periods. balb/c mice showed unrestrained parasite growth to the time of death (median survival period, msp = 12.0 days), whereas in c57bl/6 mice, parasitemia reached an initial pe ... | 1995 | 8544057 |
| [trypanosoma congolese in different species of horse flies (diptera: tabanidae) in burkina faso]. | four out of six azawak zebu bulls raised in northern burkina faso were found to be infected with trypanosomes, including trypanosoma congolense, six months after they had been transferred, uninfected, to the cirdes experimental farm at banankélédaga (southwest burkina faso). entomological surveys are carried out regularly in the area around this farm but, in one year, only 10 tsetse flies were captured, none of which showed infection in the midgut. however, a large number of tabanids were captur ... | 1995 | 8552844 |
| [improving the salivation technic in the tsetse fly for the detection of infective metatripanosomes: study of the effect of biologic and non-biologic factors in the probing behavior of the tsetse fly]. | the probing and salivation behaviour on a warm slide of three tsetse fly species or subspecies (glossina morsitans morsitans, glossina palpalis gambiensis, glossina tachinoides) was examined with respect to various parameters (species, sex, age, starvation period, trypanosome infection, quality of support). each fly was given the opportunity to probe the warm slide (38 degrees c) for 5 minutes (we mean by probing an attempt to touch the glass slide by the proboscis in a biting position). g.m mor ... | 1995 | 8552846 |
| [standardization and evaluation of a manual salivation method for the detection of trypanosoma infection in the tsetse fly (diptera: glossinidae)]. | two methods of salivation of tsetse flies, namely manual salivation and method of bruce et al. were simultaneously evaluated on 1,702 male uninfected glossina palpalis palpalis (zaire), g. palpalis gambiensis (bobo-dioulasso), g. p. gambiensis (maisons-alfort) et g. morsitans morsitans (mall) fasted for 23, 48 and 72 hours. the risk of salivation was 0.66 by the manual method and 0.01 by the method of bruce et al. the manual salivation method was standardised on 79 male g. m. morsitans (mall) in ... | 1995 | 8552848 |
| photoinactivation of trypanothione reductase and glutathione reductase by al-phthalocyanine tetrasulfonate and hematoporphyrin. | the irradiation of trypanosoma congolense trypanothione reductase (tr), human erythrocyte (hgr) and yeast glutathione reductase (ygr) with visible light in the presence of al-phthalocyanine tetrasulfonate (a1pcs4) or hematoporphyrine (hp) caused a time-dependent inactivation of these enzymes. tr was inactivated more rapidly than either hgr or ygr. half-maximal rates of inactivation were determined in the presence of 100 microm hp and 1.4-17 microm alpcs4. the photosensitized irradiation modified ... | 1996 | 8561807 |
| differentiation between culture-derived insect stages of t. brucei, t. vivax, t. congolense and t. simiae using a monoclonal antibody-based dot-elisa. | a sensitive and specific nitrocellulose (nc) membrane-based dot-elisa, utilizing a panel of monoclonal antibodies (mabs), was developed for differentiation between in vitro-derived procyclic forms of trypanosoma brucei, t. congolense and t. simiae, and epimastigotes of t. vivax. trypanosomes in suspension were applied onto nc membrane in dots and probed with unlabelled trypanosome species-specific mabs. bound mab was revealed by enzyme labelled anti-mouse igg and precipitable chromogenic substra ... | 1996 | 8587802 |
| a high prevalence of mixed trypanosome infections in tsetse flies in sinfra, côte d'ivoire, detected by dna amplification. | the prevalence of various species and subgroups of trypanosomes in the sinfra area of côte d'ivoire was determined using the polymerase chain reaction (pcr). using this technique to amplify specific satellite dna targets, it was possible to identify developmental-stage trypanosomes in the midguts and the proboscides of tsetse without expansion of parasite populations. the predominant tsetse species in the area was glossina palpalis, while g. pallicera and g. nigrofusca were also present. microsc ... | 1996 | 8587804 |
| effects of castration on luteinizing hormone secretion and response to gonadotrophin-releasing hormone in sheep infected with trypanosoma congolense. | the effects of trypanosomiasis on the endocrine function of the hypothalamo-pituitary-gonadal axis were investigated before and after castration of scottish blackface rams infected with trypanosoma congolense and uninfected controls. blood samples were collected at 15-min intervals for 6 h before and at 10, 20, 40, 60, 80, 100 and 120 min after injection of synthetic gonadotrophin-releasing hormone (gnrh, 20 micrograms iv) 2 days before infection and 26 and 54 days after infection, with castrati ... | 1996 | 8590946 |
| trypanosoma congolense: high erythropoietic potential in infected yearling cattle during the acute phase of the anemia. | n'dama (bos taurus) cattle are known to tolerate trypanosome infections, developing less severe anemia and lower parasitemia, compared to boran (bos indicus) cattle. young calves were also reported to be more resistant to trypanosomiasis than adult cattle. to explore the basis for this resistance, the erythropoietic response was evaluated in four native yearling n'dama calves and four age-matched boran calves which developed anemia over a 140- day primary infection with trypanosoma congolense cl ... | 1996 | 8617336 |
| a promotor directing alpha-amanitin-sensitive transcription of garp, the major surface antigen of insect stage trypanosoma congolense. | the major surface antigen of procyclic and epimastigote forms of trypanosoma congolense in the tsetse fly is garp (glutamic acid/alanine-rich protein), which is thought to be the analogue of procyclin/parp in trypanosoma brucei. we have studied two t.congolense garp loci (the 4.3 and 4.4 loci) whose transcription is alpha-amanitin sensitive. whilst a transcriptional gap 5' of the first garp gene in the cloned region of the 4.4 locus could not be detected, such a gap was present in the 5' flank o ... | 1996 | 8628650 |
| resistance to diminazine aceturate by trypanosoma congolense from cattle in the zambezi valley of zimbabwe. | the susceptibility of 14 stocks of trypanosoma congolense, recently isolated from cattle, to therapeutic doses of diminazene aceturate and to isometamidium chloride was assessed in laboratory mice. eight isolates were readily susceptible to the normal therapeutic dose of diminazene, two were resistant to the drug at 14 mg kg-1, and four were totally resistant at 28 mg kg-1. all the isolates were susceptible to isometamidium chloride at 0.5 mg kg-1. these observations highlight the need for regul ... | 1995 | 8644445 |
| trypanosoma congolense infection in sheep: ultrastructural changes in the skin prior to development of local skin reactions. | events occurring in the skin of sheep prior to development of trypanosoma congolense-induced local skin reactions (chancres) were studied using electron microscopy. three days after infection, few trypanosomes were present in the dermal collagen. however, these parasites were more abundant 5 days after infection, and were also found in dermal lymphatics and in the connective tissue matrix between collagen bundles. mast cells in the skin obtained 5 days after infection showed evidence of degranul ... | 1995 | 8644458 |
| trypanosoma congolense: b-lymphocyte responses differ between trypanotolerant and trypanosusceptible cattle. | trypanosomiasis is a serious constraint to livestock production in sub-saharan africa. some breeds of cattle are genetically more resistant to the pathogenic effects of trypanosome infection. we measured b-cell activation and the quantity and isotype of antibody produced at the cellular level in six trypanotolerant n'dama and five trypanosusceptible boran cattle. the frequencies of spleen cells secreting total and parasite-specific igm and igg were measured prior to and 16, 28, and 35 days after ... | 1996 | 8654538 |
| acquisition of resistance to the tick amblyomma variegatum in boran cattle, bos indicus and the effects of trypanosoma congolense and babesia bigemina on host resistance. | resistance was induced in cattle to the tick amblyomma variegatum by five consecutive infestations with nymphs and adults. using the principal component analysis (pca), it was found that percentage of adults engorged, percentage of adults which died, percentage of nymphs which engorged, percentage of nymphs which moulted and percentage of nymphs which died, were the main indicators of resistance against a. variegatum. the percentages of nymphs which engorged or moulted after the third infestatio ... | 1996 | 8686177 |
| are stable flies (diptera: stomoxyinae) vectors of trypanosoma vivax in the central african republic? | the epidemiology of trypanosoma vivax infections was studied at a riverside site in the ouro-djafoun livestock area situated in the central african republic during the period between july 1991 and july 1992. this paper examines the possibility that stable flies (diptera: stomoxyinae) were also vectors of this trypanosome species in a non-cyclic way. previous studies have revealed that the usual cyclic transmission by the tsetse fly glossina fuscipes fuscipes was probably not the only transmissio ... | 1996 | 8721295 |
| in vivo trypanocidal activities of new s-adenosylmethionine decarboxylase inhibitors. | a series of novel aromatic derivatives based on the structure of methylglyoxal bis(guanylhydrazone) (mgbg) was examined for trypanocidal activities in human and veterinary trypanosomes of african origin. one agent, cgp 40215a, a bicyclic analog of mgbg which also resembles the diamidines diminazene (berenil) and pentamidine, was curative of infections by 19 isolates of trypanosoma brucei subspecies as well as a trypanosoma congolense isolate. several of these isolates were resistant to standard ... | 1996 | 8726018 |
| trypanosoma congolense infection in sheep: cellular phenotypes in lymph and lymph nodes associated with skin reactions. | intradermal inoculation of sheep with culture-derived metacyclic forms of trypanosoma congolense resulted in the development of localized skin reactions (chancres) and enlargement of the draining lymph nodes 7 days after infection. changes in the expression of surface antigens of lymphocytes in lymph leaving the affected skin reactions and in the associated lymph nodes were monitored by cannulating the afferent and efferent lymphatic ducts. trypanosomes appeared in afferent and efferent lymph 3 ... | 1996 | 8729080 |
| bioavailability, pharmacokinetics, and tissue distribution of 14c homidium after parenteral administration to boran cattle. | the absorption, distribution and elimination characteristics of 14c homidium have been described in non-infected and trypanosoma congolense-infected cattle treated with 14c homidium chloride by either intramuscular (i.m.) or intravenous (i.v.) injection at a dose level of 1 mg/kg body weight. results show that the mean (+/-sd) elimination of the drug from plasma followed a biexponential process, with half-lives of 0.084 +/- 0.006 h and 97.66 +/- 16.28 h for the distribution and elimination phase ... | 1996 | 8735423 |
| effect of nutritional level on bodyweight, degree of anaemia and carcase composition of sheep infected with trypanosoma congolense. | the influence of nutritional level on the bodyweight, degree of anaemia and carcase composition of 24 sheep infected experimentally with trypanosoma congolense was investigated. the infection caused a marked retardation of growth in the animals fed a low protein ration whereas the infected and control animals fed a high protein ration grew at similar rates. both groups of infected animals developed similar degrees of anaemia but the infected group fed the high protein diet tended to sustain a hi ... | 1996 | 8745251 |
| rise in erythropoietin concentrations in experimental trypanosoma congolense infection of calves. | a bioassay was used to measure erythropoietin (epo) concentrations in calves with haemorrhagic anaemia due to blood loss and in calves with anaemia due to trypanosoma congolense infection. the bioactivity of epo was measured in the assay by its stimulatory effect on 125i-deoxyuridine incorporation in spleen cells from phenylhydrazine-treated mice. erythropoietin concentrations in blood-volume-depleted calves were elevated 6 h after blood loss, maximal (1225 mu/ml) at 33 h and below detection lim ... | 1995 | 8746957 |
| glycosyl-phosphatidylinositols of trypanosoma congolense: two common precursors but a new protein-anchor. | the parasitic protozoan trypanosoma congolense exhibits a dense surface coat which is pivotal for immunoevasion of the parasite. this dense surface coat is made of a single protein species, the variant surface glycoprotein, which is present in a high copy number. the protein is anchored to the plasma membrane by a glycosyl-phosphatidylinositol membrane anchor. a detailed study of the structure of t. congolense strain 423 (clone benat 1.3) variant surface glycoprotein glycosyl-phosphatidylinosito ... | 1996 | 8757286 |
| evaluation of three antigen detection tests (monoclonal trapping elisa) for african trypanosomes, with an isolate of trypanosoma vivax from french guyana. | preliminary studies in french guyana with sheep experimentally infected with a local isolate of trypanosoma vivax tended to show poor sensitivity and/or specificity of the monoclonal antibodies used in kits for the antigen-detection (ag) elisa for t. vivax, t. brucei, and t. congolense. to reevaluate these kits, 4 calves were infected at ilrad, nairobi, kenya, with the same isolate. blood samples were taken daily for 51 days, and examined directly on blood smears and buffy coat, and using ag-eli ... | 1996 | 8784499 |
| effect of tsetse control on trypanosome prevalence in livestock: problems of experimental design and statistical interpretation--a case study in northern côte d'ivoire. | as part of a study on livestock productivity under trypanosomosis risk in the region of boundiali, northern côte d'ivoire, 21 herds of cattle (n'dama, baoulé and zebu crosses) and 20 flocks of djallonké and djallonké x sahel sheep were monitored monthly for body weight, packed red cell volume and trypanosomal parasitaemia over various periods between january 1984 and december 1992. a tsetse control campaign using biconical traps impregnated with alpha-cypermethrin started in december 1987. tsets ... | 1996 | 8804163 |
| evaluation of an antigen detection-elisa test for the diagnosis of trypanosomiasis in naturally infected cattle. | the sensitivity and the specificity of the antigen detection elisa proposed by nantulya and lindqvist (1989) for the diagnosis of african animal trypanosomiasis have been assessed in naturally-occurring infections. 1633 cattle were sampled in trypanosomiasis endemic area and examined for trypanosomes by darkground/phase contrast buffy-coat method described by murray et al. (1977) and for circulating antigen by elisa. fifty sera from markoye, a tsetse free area in north of burkina faso, and 49 se ... | 1995 | 8826113 |
| trypanosoma congolense: tissue distribution of long-term t- and b-cell responses in cattle. | memory t- and b-cell responses to trypanosome antigens were measured in peripheral blood mononuclear cells, spleen and lymph node cells obtained from four trypanotolerant n'dama cattle which had been exposed to six experimental infections with trypanosoma congolense. these cattle were treated with trypanocidal drugs following each infection and had remained aparasitemic for 3 years prior to this study. the antigens used were whole trypanosome lysate, variable surface glycoprotein, a 33-kda cyste ... | 1995 | 8847087 |
| field evaluation of a dot-elisa for the detection and differentiation of trypanosome species in infected tsetse flies (glossina spp.). | a rapid, visually read, dot-elisa developed for the detection and differentiation of trypanosome species in tsetse flies (glossina spp.), was field tested alongside the standard fly dissection method on a range in south eastern kenya. of 104 g. pallidipes dissected, 2 were found to be infected with trypanosomes in their midguts. by the dissection method the infecting trypanosome species could not be identified, as both flies had no salivary gland infections. however, using the dot-elisa, the 2 f ... | 1996 | 8851860 |
| ultrastructural changes on various trypanosoma spp. after a 30-year storage period in liquid nitrogen. | four trypanosoma species were examined for damage following prolonged storage in liquid nitrogen (-196 degrees c). the stabilates were successfully recovered after a cryopreservation period of approximately 30 years. the structure of specimens was studied by means of light microscopy and scanning (sem) and transmission (tem) electron microscopy. all of the species tested--t. evansi, t. equinum, t. brucei, and t. congolense--proved to be infective to mice. however, as compared with controls, the ... | 1996 | 8897507 |
| pharmacokinetics, bioavailability and tissue residues of [14c]isometamidium in non-infected and trypanosoma congolense-infected boran cattle. | in this paper, pharmacokinetics, bioavailability and tissue residues are reported in non-infected and trypanosoma congolense-infected boran steers following either intravenous or intramuscular injection of [14c]isometamidium at a dose rate of 1 mg kg-1 body weight. two differently labelled compounds of isometamidium were used; 6-14c (ismm-1) and ring-u-14c (ismm-2). the cattle were divided into 5 groups: group 1 consisted of 3 non-infected cattle treated with ismm-1 by intravenous injection; gro ... | 1996 | 8910653 |
| use of insecticide-impregnated targets for the control of tsetse flies (glossina spp.) and trypanosomiasis occurring in cattle in an area of south-west ethiopia with a high prevalence of drug-resistant trypanosomes. | in the ghibe valley, south-west ethiopia, a tsetse control trial using deltamethrin-impregnated targets was started in may 1990. the mean relative density of the main vector, glossina pallidipes, fell from 2.1 flies per trap per day in the 12 months prior to introduction of tsetse control to 0.41 flies per trap per day in the 12 months after tsetse control was initiated. the annual mean prevalence of trypanosoma congolense infections in cattle fell from 32% in the 2 years before tsetse control t ... | 1996 | 8911444 |
| heterophile antibodies to chicken erythrocytes in sheep infected with trypanosoma congolense. | high hemagglutinin titres against chicken erythrocytes were detected in the sera of trypanosoma congolense-infected sheep. adsorption of sheep sera with solubilized t. congolense resulted in marked reduction of hemagglutinin titre. heat inactivation of the sera at 56 degrees c for 30 min had no demonstrable effects on the hemagglutinin titre. sera collected from the sheep before trypanosome infection did not agglutinate chicken erythrocytes. on the other hand, erythrocytes of horse, donkey and d ... | 1996 | 8917863 |
| nitric oxide synthesis is depressed in bos indicus cattle infected with trypanosoma congolense and trypanosoma vivax and does not mediate t-cell suppression. | infection with african trypanosomes causes the diseases sleeping sickness in humans and nagana in cattle in sub-saharan africa. suppression of cellular immune responses is a feature of trypanosomiasis in bovine, human, and murine hosts. some aspects of immunosuppression in the murine model are mediated by nitric oxide (no) produced by gamma interferon (ifn-gamma)-activated macrophages. we have investigated whether a similar mechanism is responsible for t-cell unresponsiveness in bovine trypanoso ... | 1996 | 8926077 |
| trypanosoma congolense: a comparison of t-cell-mediated responses in lymph nodes of trypanotolerant and trypanosusceptible cattle during primary infection. | a comparison of t-cell-mediated immune responses in trypanotolerant n'dama and susceptible boran cattle during primary infection with tsetse-transmitted trypanosoma congolense was conducted to assess whether different patterns of t-cell activation occurred during trypanosome infection. proliferation and ifn-gamma synthesis in response to trypanosome antigens and to the mitogen con a were measured in lnc before infection and 10 and 35 days postinfection. phenotypic analysis of lnc was also carrie ... | 1996 | 8948321 |
| localisation of acid phosphatase activity on the surface of bloodstream forms of trypanosoma congolense. | in vitro, living bloodstream forms of trypanosoma congolense were shown to hydrolyse p-nitrophenyl phosphate, a substrate for phosphatases. this activity appears to be from an acid phosphatase because it was enhanced at low ph values, was inhibited by the acid phosphatase inhibitor sodium fluoride, and was not inhibited by the alkaline phosphatase inhibitor tetramisole. the activity did not appear to be secreted into the surrounding medium by the living parasites although phosphatase activity co ... | 1996 | 8948332 |
| trypanosomosis in intensively reared muturu calves in nigeria. | | 1995 | 8966766 |
| comparative evaluation of the prophylactic effect of slow release devices containing homidium bromide and isometamidium on trypanosoma congolense in rabbits. | two consecutive experiments were carried out to evaluate the prophylactic effect of biodegradable slow release devices (srd), containing either isometamidium or homidium bromide. rabbits subcutaneously implanted with srd, were challenged with different trypanosoma congolense stocks at regular intervals between 1 and 6.5 months after treatment. in a first experiment the efficacy of two types of isometamidium-srd (poly(d,l-lactide) and poly(d,l-lactide-co-glycolide)) was compared with the classica ... | 1996 | 8966986 |
| pharmacokinetics of the chemoprophylactic and chemotherapeutic trypanocidal drug isometamidium chloride (samorin) in cattle. | pharmacokinetics of the prophylactic and therapeutic trypanocidal drug isometamidium chloride were examined comprehensively for the first time in cattle using a recently described, highly sensitive elisa. cattle were administered single intravenous (n = 4) or intramuscular (n = 5) doses of isometamidium at a rate of 1.0 mg x kg(-1) body weight. concentration data were analyzed over at least 14 days (intravenous treatment) or 30 days (intramuscular treatment) using compartmental and noncompartmen ... | 1996 | 8971142 |
| thyroid status and adenosine triphosphatase activity in experimental trypanosoma congolense infection in rabbits. | the effect of trypanosome infection on the plasma levels and ratios of tri-iodothyronine (t3) and thyroxine (t4) as well as the activity of mitochondrial adenosine triphosphatase (atpase) were investigated. three groups of sexually mature white new zealand rabbits were used. group 1 consisted of the normal non-infected rabbits, group 2 were experimentally infected with trypanosoma congolense and group 3 were infected but given replacement doses of thyroxine. the infected animals (group 2) showed ... | 1996 | 8979423 |
| a comparative study of the parasitological buffy coat technique and an antigen enzyme immunoassay for trypanosome diagnosis in sequential trypanosoma congolense infections in n'dama, gobra zebu and n'dama x gobra crossbred cattle. | the buffy coat/dark ground techniques (bct) and an antigen enzyme immunoassay (ag-elisa) were compared for the diagnosis of trypanosome infection in n'dama, gobra zebu and n'dama x gobra (f1) crossbred cattle following two sequential experimental trypanosoma congolense infections. both first and second challenge were performed by intradermal needle inoculation of trypanosome bloodstream forms. during the course of the first challenge, the overall trypanosome percentage of positive cases detected ... | 1996 | 8988308 |
| trypanosome characterization by polymerase chain reaction in glossina palpalis gambiensis and g.tachinoides from burkina faso. | following the discovery of four cases of african human trypanosomiasis, an entomological survey was conducted along the mouhoun river in southwest burkina faso to collect glossina palpalis gambiensis and g.tachinoides. among 226 flies dissected, 4.87% (eleven individuals) were infected in midgut or proboscis, but never in the salivary glands. polymerase chain reaction analysis was undertaken, and was able to characterize all the proboscis infections, and half of the midgut infections. only trypa ... | 1996 | 8994137 |
| [evaluation of vectorial capacity of glossina tachinoides (diptera, glossinidae) infected by trypanosoma (nannomonas) congolense: epidemiological implications]. | a total of 182 glossina tachinoides were infected with trypanosoma congolense savannah type. infection rates were determined according to microscopical examination of dissected flies and pcr on proboscis. different techniques of trypanosomes detection in the saliva of live tsetse flies were compared. results show a high percentage of immature infection rates. pcr amplification of trypanosomes in tsetse flies proboscis confirm parasitological observations. the salivation technique showed fluctuat ... | 1996 | 9008737 |
| [experimental infection of glossina morsitans morsitans (mall) with trypanosoma congolense (zre/g143/90). parasite cycle and vector competence in the tsetse fly]. | this report presents an experimental study of the life cycle of trypanosoma congolense (zre/g 143/90) in relation to the vectorial competence of glossina morsitans (mall). the rate of engorgement at the time of an infectious meal and the mortality before day 15 of the life cycle were not significantly different between male and female flies. the mesocyclic forms of trypanosomes were regularly observed in the proventriculus, crop duct, oesophagus, cibarium and proboscis, except in the crop. on da ... | 1996 | 9026227 |
| improvement of blood and fly gut processing for pcr diagnosis of trypanosomosis. | we have adapted a simple and efficient technique to detect trypanosomes in human blood, without dna purification, and increased the sensitivity threshold to 1 parasite in 1 ml. we have then applied it for detection of parasites in midguts of tsetse flies, negative by microscopy. this technique has been developed for field conditions and could greatly facilitate epidemiological studies. | 1996 | 9033912 |
| pathophysiology of trypanosoma congolense infection in two breeds of sheep, scottish blackface and finn dorset. | the pathophysiology of trypanosoma congolense infection was studied in two breeds of sheep, the scottish blackface (sb) and finn dorset (fd), which were known from previous studies to differ significantly in their susceptibility to haemonchosis, in which anaemia is also the primary pathophysiological effect. it was found that infected sb and fd lambs developed similar intensities of parasitaemia. however, infected sb lambs developed a higher degree of anaemia, more severe thrombocytopaenia and h ... | 1997 | 9066067 |
| the influence of dietary protein on some blood biochemical parameters in scottish blackface sheep experimentally infected with trypanosoma congolense. | the present study investigated the influence of dietary protein on some blood biochemical parameters, namely lipids, proteins, iron, glucose and b-hydroxybutyrate, in scottish blackface sheep infected with trypanosoma congolense, and given either a low protein (51.5 g digestible crude protein per day) or a high protein (116 g digestible crude protein per day) diet. both low and high protein diets were isocaloric and animals were monitored for 10 weeks after infection. it was observed that infect ... | 1997 | 9066068 |
| detection of trypanosoma brucei, t. congolense and t. vivax infections in cattle, sheep and goats using latex agglutination. | a monoclonal antibody-based latex agglutination test for detection of circulating trypanosome antigens in animal serum was evaluated for the ability to detect natural t. brucei, t. congolense and t. vivax infections in cattle, sheep and goats in ghana. the test detected antigens in 180/422 (42.7%) of cattle, 27/131 (20.6%) of sheep and 14/79 (17.7%) of the goats. by comparison, the microplate-based antigen-elisa gave similar results (p > 0.01), detecting trypanosome antigens in 41.7% of the catt ... | 1997 | 9076533 |
| the primary structure of trypanosoma (nannomonas) congolese variant surface glycoproteins. | the complete nucleotide sequences were determined for three transcripts each encoding a different variant surface glycoprotein (vsg) of trypanosoma (nannomonas) congolense. the nucleotide sequence was determined also for a transcript encoding a fourth vsg, but this was truncated. the data obtained confirm absence of the canonical polyadenylation signal, lack of conserved sequence elements in the 3' untranslated region, and heterogeneity in the spliced-leader acceptor site in the t. congolense vs ... | 1997 | 9085918 |
| concentrations of isometamidium in the sera of cattle challenged with drug-resistant trypanosoma congolense. | the relationship between serum concentrations of the prophylactic trypanocidal drug isometamidium chloride and protection against tsetse challenge with two populations of trypanosoma congolense was investigated in boran (bos indicus) cattle, using an isometamidium-elisa. isometamidium chloride (samorin) was administered to cattle at a dose rate of 1.0 mg/kg body weight by deep intramuscular injection. thereafter, the animals were challenged at monthly intervals with either a drug-sensitive clone ... | 1997 | 9088422 |
| detection of trypanosoma congolense and t. brucei subspecies in cattle in zambia by polymerase chain reaction from blood collected on a filter paper. | to facilitate epidemiology studies of african trypanosomiasis in cattle in zambia, we adapted a polymerase chain reaction (pcr) method using blood spotted on filter papers. for easy preparation of template dna from the dried blood, we adapted a simple dna extraction method using chelex-100, an anion-exchange resin. using primers directed for repetitive nuclear dna sequences, species-specific dna amplifications were detected from the blood of rats infected with zambian isolates of t. congolense a ... | 1997 | 9089719 |
| susceptibility of three breeds of ugandan goats to experimental infection with trypanosoma congolense. | this study has indicated that differences in susceptibility to trypanosoma congolense infection exist among the 3 main breeds of goats in uganda namely, kigezi, mubende and small east african (sea). the kigezi goats appeared to be the most susceptible suffering more severe anaemia, greater retardation of growth and more deaths than the other 2 breeds following experimental infection with try-panosoma congolense. the small east african goats appeared to be least susceptible. following treatment a ... | 1997 | 9090009 |
| long-term occurrence of trypanosoma congolense resistant to diminazene, isometamidium and homidium in cattle at ghibe, ethiopia. | ten trypanosome isolates were collected at random from cattle at ghibe, ethiopia, in february 1993 and all shown to be savannah-type trypanosoma congolense. when inoculated into naïve boran (bos indicus) calves, all 10 isolates were resistant to diminazene aceturate (berenil), isometamidium chloride (samorin) and homidium chloride (novidium) at doses of 7.0 mg/kg body weight (b.w.), 0.5 mg/kg b.w. and 1.0 mg/kg b.w., respectively. in order to determine whether this multiple-drug resistance was e ... | 1997 | 9107367 |
| sensitivity of segregation analysis to data structure and transformation: a case study of trypanotolerance in mice. | sensitivity of segregation analysis for data structure and data transformation was studied using data from two trials in which mice were challenged at three months of age with a cloned isolate of trypanosoma congolense and survival time was recorded. data included records from three inbred strains (c57bl/6 (tolerant), a/j, and balb/c (both susceptible)) and their crosses. data were standardized and normalized using a modified power transformation. segregation analysis was applied to both untrans ... | 1997 | 9134708 |
| prophylactic effects of isometamidium- and ethidium-sustained release devices against trypanosoma congolense in cattle. | two successive experiments were carried out in which three cows were treated by intramuscular injection of either 0.5 mg/kg isometamidium or 1 mg/kg ethidium and compared with another group of three cows which received a subcutaneously implanted sustained release device (srd) containing the same dose of drug. the prophylactic effect of both drug formulations was evaluated by exposing the animals at monthly intervals to glossina morsitans morsitans infected with trypanosoma congolense. the averag ... | 1997 | 9140511 |
| modelling trypanosoma congolense parasitaemia patterns during the chronic phase of infection in n'dama cattle. | we reanalyzed parasitaemia profiles of the trypanotolerant n'dama cattle (bos taurus), consecutively infected with the same four clones of trypanosoma congolense. our analysis shows that each individual parasitaemia is characterized by progressively longer intervals between parasites waves. this pattern is most visible during the chronic phase of infection. in addition, the last of the four infections had a significantly larger overall duration of inter-wave intervals. we retrieved these pattern ... | 1997 | 9149284 |
| the daily feeding rate of tsetse (diptera: glossinidae) on cattle at galana ranch, kenya and comparison with trypanosomiasis incidence. | at galana ranch, south-eastern kenya, for 2 days each month from january to may 1993. glossina pallidipes and g. longipennis were sampled around a heifer for 30 min every hour from 06:00 to 19:00. there was a seasonal decline in tsetse abundance; estimates of the total number attracted to the heifer in 1 day ranged from 556 g. pallidipes in january to 0 in may and 122 g. longipennis in february to 27 in may. the number of tsetse estimated to have fed on the heifer in 1 day during peak months was ... | 1997 | 9164602 |
| effect of diminazene aceturate on the infectivity and transmissibility of drug-resistant trypanosoma congolense in glossina morsitans centralis. | to determine the duration after treatment of cattle with diminazene aceturate that the drug influences the tsetse infectivity and transmissibility of a drug-resistant trypanosoma congolense, six boran cattle were infected with t. congolense il 3338 via the bites of glossina morsitans centralis. at the first peak of parasitaemia, different groups of 120 teneral g. m. centralis were fed on one occasion on each animal, 1 h before treatment with diminazene aceturate at a dose of 3.5 mg kg-1 body wei ... | 1997 | 9195705 |
| effect of different cytokines on the growth of trypanosoma congolense cultured under axenic conditions. | we previously reported that susceptible balb/c mice had high amounts of interleukin-4 (il-4) and interleukin-10 (il-10) in their plasma after infection with trypanosoma congolense and the levels of these cytokines decreased dramatically after berenil treatment. these observations instigated us to speculate that these cytokines might be directly affecting the growth of these parasites. previously, it was reported that interferon gamma (ifn-gamma) had a growth stimulatory effect on t. brucei bruce ... | 1997 | 9195706 |
| the influence of supplementation with cotton seed cake on the resistance of ugandan goats to primary and secondary challenges with trypanosoma congolense and on their response to treatment. | the present study investigated the influence of supplementation with cotton seed cake on the resistance of the small east african breed of goats to primary and secondary challenges with trypanosoma congolense and on their response to chemotherapy with diminazene aceturate. the supplemented group received 300 g of cotton seed cake per day in addition to about 500 g of fresh napier grass which was available to the unsupplemented group. it was observed that the supplemented infected (si) group tend ... | 1997 | 9195711 |
| cross-resistance associated with development of resistance to isometamidium in a clone of trypanosoma congolense. | resistance to isometamidium was increased 94-fold in a clone of trypanosoma congolense (clone il 1180) by repeated subcurative treatment of infected mice for 11 months. this was associated with 3.4-, 33-, and 4.2-fold increases in resistance to diminazene, homidium, and quinapyramine, respectively. both t. congolense il 1180 and the resistant derivative were able to undergo cyclical development in glossina morsitans centralis tsetse flies, producing hypopharyngeal infection rates of 40.0 and 39. ... | 1997 | 9210695 |
| the role of anti-variable surface glycoprotein antibody responses in bovine trypanotolerance. | it has been reported that some breeds of cattle such as the n'dama mount a more effective antibody response to the variable surface glycoprotein coat of trypanosomes and that this may contribute to their ability to control the infection. thus we have investigated antibody responses to surface exposed epitopes of the variable surface glycoprotein in trypanosoma congolense-infected n'dama (trypanotolerant) and boran (susceptible) cattle. similar titres and isotypes were found in both n'damas and b ... | 1996 | 9223176 |
| influence of trypanosoma congolense infection on some blood inorganic and protein constituents in sheep. | the present study was designed to investigate the changes in plasma concentrations of zinc, copper, calcium, magnesium, inorganic phosphate, total protein, albumin, globulin, and serum iron and iron-binding capacity in sheep infected with trypanosoma congolense. it was observed that infection did not have a significant effect on the plasma concentrations of zinc, copper, calcium, magnesium and inorganic phosphate. the serum iron concentrations in infected animals were higher, but not significant ... | 1996 | 9239939 |