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the histopathology of experimental disease produced in mice infected with trypanosoma vivax.an acute form of trypanosomiasis (course of disease 4 to 8 days) was produced in mice experimentally infected with a strain of t. vivax. the features of the disease were: a parasitemia which appeared to increase exponentially from 23.8 to 243.6 times 10(6) trypanosomes per ml within the last 24 hours of the disease; anaemia was not severe in the disease in mice; the basic histological lesion was generalized fibrin thrombus formation in the blood vessels of the heart, lung, spleen and brain; tryp ...19751987
susceptibility of a rodent-adapted strain of trypanosoma vivax to berenil, samorin and novidium.the susceptibility of a rodent-adapted strain of trypanosoma vivax (leeflant strain y58) to berenil, samorin and novidium was tested in mice. when infected mice were treated on the second day of detectable parasitaemia, there was complete cure with berenil at 10 mg/kg, novidium at 4 mg/kg and samorin at 0.2 mg/kg body weight respectively. berenil and novodium at lower doses rendered the mice aparasitaemic for a few days followed by heavy parasitaemia (relapse) and death. lower doses of samorin, ...197716467
eperythrozoon ovis. iii. the effect of infection on blood ph, concentrations of pyruvate, lactate and glucose in blood, haematology, and on concurrent and superimposed trypanosoma vivax infection in sheep.infections of sheep with eperythrozoon ovis has been shown to increase pyruvate and lactate concentrations in blood and to reduce blood ph over a period of 10-14 days post-inoculation. there was no effect on the concentration of blood glucose. however, if care is not taken to inhibit glycolysis, the concentration of blood glucose in samples of blood taken for analysis falls markedly. rapid destruction of erythrocytes started about 10 days post-inoculation and was progressive. superimposition of ...197833476
suppression of antibody response to leptospira biflexa and brucella abortus and recovery from immunosuppression after berenil treatment.zebu cattle infected with either trypanosoma congolense eatro 1800 or trypanosoma vivax eatro 1721 had suppressed humoral immune responses to leptospira biflexa injected intravenously and to attenuated brucella abortus injected subcutaneously. t. congolense infections were more suppressive than t. vivax infections. in cattle infected with t. vivax, the suppression of immune responses to both bacterial immunogens was abrogated when the animals were treated with berenil at the time of antigen admi ...1979118933
conversion of dihydroorotate to orotate in parasitic protozoa.the conversion of dihydroorotate to orotate, one of the key reactions in the de novo pyrimidine biosynthetic pathway, has been studied in a number of parasitic protozoa. enzyme activities capable of carrying out this reaction were detected in six members of the kinetoplastida (trypanosoma brucei, trypanosoma congolense, trypanosoma vivax, trypanosoma lewisi, trypanosoma cruzi, leishmania enriettii) and three members of the genus plasmodium (p. knowlesi, p. berghei, p. gallinaceum). the mechanism ...1979217438
the phosphoglucose isomerases of the bloodstream forms of trypanosoma brucei and trypanosoma vivax.1. the phosphoglucose isomerases (pgi's) of the bloodstream forms of trypanosoma brucei and t. vivax have been purified some 150-fold, using cellulose ion-exchange chromatography, gel filtration and isoelectric focussing. 2. the two trypanosome enzymes showed many similarities in kinetic properties, but differed from each other somewhat in thermal stability and in isoelectric point. 3. both trypanosome enzymes differ from pgi's from other sources in having a higher ki for the competitive inhibit ...1978318331
serological evidence for the geographical distribution of trypanosoma vivax in the new world. 1977339426
studies on trypanosoma vivax: comparison of parasitological diagnostic methods. 1978344244
immunosuppressive effect of trypanosoma congolense and trypanosoma vivax on the secondary immune response of cattle to mycoplasma mycoides subsp mycoides.trypanosoma congolense and t vivax infections in cattle were shown to have a suppressive effect on the secondary humoral immune response to m mycoides. the trypanosome infections caused an involution of the thymus. the secondary response was biphasic in nature and was unrelated to infection with trypanosomes.1978373035
inhibition of bovine bone marrow granulocyte/macrophage colony formation in vitro by serum collected from cattle infected with trypanosoma vivax or trypanosoma congolense.serum collected from cattle infected with trypanosoma vivax or trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in methyl cellulose cultures. maximum inhibition was caused by serum collected two and three weeks post infection. the degree of inhibition appeared to be related to the degree of parasitemia. inhibition of erythroid colony formation by serum collected from these animals was not observed.1979483385
pancarditis in trypanosoma vivax infection in cattle.in cattle chronically infected with t. vivax y 58, a mononuclear pancarditis with extravascular trypanosomes is described. it has been considered as a local immune response to these extravascular trypanosomes. no autoantibodies for heart tissue have been found.1979483387
trypanosoma vivax and immunosuppression. 1979518164
[studies on south american trypanosoma vivax i. experimental infection induced in outbred white rats by chemical immunosupression and splenectomy (author's transl)]. 1979539349
effective treatment of trypanosoma vivax infections with salicylhydroxamic acid (sham). 1978653794
the influence of lorry transport on the trypanosoma vivax infection rate in nigerian trade cattle.in nigeria in 1974 and 1975 there was an apparent sharp reduction in the prevalence of trypanosomiasis of cattle at several markets and control points. some of the decrease appears to be due to the tsetse eradication programmes and sahelian drought, but the change to lory transport as the principal means of moving cattle from the northern grazing areas to the south-western markets, which replaced a trek of at least three weeks, was probably an important factor.1978705892
determination of volumes of trypanosoma vivax and t. congolense separated from cattle blood.trypanosomes were separated on deae cellulose columns from blood samples taken during the first parasitemic wave in t. vivax or t. congolense infected cattle. the mean volume of t. vivax organisms in five steers increased from 16.3 fl se 0.7 on day five to 20.7 fl se 0.7 on day eight. assuming an even distribution of t. vivax throughout the vasculature, the total trypanosome volume at peak parasitemia (36.400 trypanosomes per microliter on day six) was calculated to be about 0.067% of the blood ...1978675845
experimental bovine trypanosomiasis (trypanosoma vivax and t. congolense). i. sumptomatology and clinical pathology.twenty five cattle were infected with t. vivax, 25 with t. congolense, and 25 served as controls. pathogenic clinical signs of trypanosomal infection were not observed. secondary bacterial infections were common. fever, increased heart and respiratory rates, anorexia, and emaciation developed. elevations in parasitemai and body temperature were positively correlated in the t. vivax group. infected groups were affected non-uniformly, with some animals in each group remaining asymptomatic and tend ...1979542998
trypanosoma vivax: sequence of antigenic variants in mice and goats. 1979510439
progressive serum protein changes in experimental infections of calves with trypanosoma vivax. 1975806613
long term variations in trypanosome infection rates in highly infected tsetse flies on a cattle route in south-western nigeria.one thousand, nine hundred and ninety-seven male and 1988 female glossina morsitans submorsitans were dissected at ogbomosho, on a trade cattle route in south-western nigeria, from june 1970 to august 1973. of male flies, 1307 (65-45%) were infected by trypanosoma vivax trypanosomes, 66 (3-31%) by the subgenus nannomonas (congolense group) and three (0.15%) by the subgenus trypanozoon (brucei group). of flies, 1236 (62-17%) had t. vivax infections, 80 (4-02%) had infections of the subgenus nanno ...1977849015
[extravascular localization of trypanosoma vivax in cattle (author's transl)].in 2 cattle experimentally infected with trypanosoma vivax, strain eatro 1695, trypanosomes were found in the marginal sinus of one of several lymph nodes examined. one animal showed trypanosomes in a small focus in the interstitial tissue of the heart. it is concluded that trypanosoma vivax can not be regarded as a strict plasma parasite.1977860327
trypanosoma brucei and trypanosoma vivax: antigen-antibody complexes as a cause of platelet serotonin release in vitro and in vivo. 1977891705
the persistence in the field of two characteristic isoenzyme patterns in nigerian trypanosoma vivax. 1977921372
evaluation of the indirect fluorescent antibody test for detecting trypanosoma vivax in south american cattle.the indirect fluorescent antibody test (ifat) as used in africa for detecting bovine trypanosomiasis was adapted for use in south america and evaluated. antigen consisted of trypanosoma vivax laden bovine blood fixed in a 60 : 40 : : acetone : methanol solution. the test detected initial titres of 1 : 50 and 1 : 100 at an average of 13.1 and 15.9 days post parasitaemia (pp). maximum titres as high as 1 : 400 developed in eight calves at an average of 23.4 days pp. in another calf, 109 days pp we ...1976781765
letter: cft in trypanosoma vivax infection. 1976960517
the pathology and pathogenesis of trypanosoma vivax infection in the goat.acute and chronic forms of disease can be distinguished in trypanosoma vivax infection in the goat. the main difference between the acute and chronic form seems to be the presence of microthrombi in the acute stage of infection; these consist of platelets, trypanosomes, monocytoid cells and some fibrin. this thrombus formation seems directly related to the high parasitaemia in acute trypanosomiasis and may result in ischaemia which could also explain the haemorrhages, the oedema of the lungs and ...19761025633
free plasma amino acid profiles of normal and trypanosoma vivax infected sheep.the free amino acids in the plasma of normal and trypanosoma vivax infected sheep and also in the trypanosome organism per se were determined. threonine, asparagine, methionine, tyrosine, citrulline, ornithine, histidine, arginine and urea were significantly decreased in the plasma of infected sheep. alanine was significantly elevated in plasma of infected sheep. valine, isoleucine, leucine values were also elevated in the plasma of infected sheep, although not at significant level. taurine was ...1978726045
studies on isolation and drug sensitivity of trypanosoma vivax in northern nigeria.in a study to investigate the occurrence in cattle of trypanosoma vivax strains resistant to the normal therapeutic dose of homidium, 47 isolates of t. vivax were collected from 10 different trypanosomiasis treatment centres in the north central state of nigeria. of these 47 isolates, 23 produced infection in the experimental animals that were used for subsequent drug sensitivity trials. while all but one of the experimental cattle inoculated with t. vivax became infected, less than 50% of the e ...19751124965
on the cultivation of trypanosoma vivax: a tale of two visits in nigeria.a new method is presented for obtaining in vitro development of the insect cycle of trypanosoma vivax. bloodstream trypanosomes from infected sheep were inoculated to tsete fly organ cultures in a modified eagle's medium with 20% sheep serum, and incubated at 28 c. the organisms multiplied first as elongate spiral trypomastigotes. in successful cultures these transformed to epimastigotes. the epimastigotes multiplied extensively to form dense layers attached to formed structures, especially to p ...19751117366
a comparison of the role of kinins and serotonin in endotoxin induced fever and trypanosoma vivax infections in the goat.goats were infected with trypanosoma vivax or inoculated with a low pyrogenic dose of lipopolysaccharide (lps) obtained from escherichia coli or salmonella typhimurium in order to obtain evidence about the role of kinins and serotonin in the pathogenesis of trypanosomiasis and in endotoxin induced ruminal stasis. the following conclusions were made: (1) whole blood serotonin and bradykinin-like activity levels and clinical symptoms during fever, induced by lps e coli or t vivax infection are not ...1976799824
serum protein changes in cattle infected with trypanosoma vivax. 19751145713
[an electron microscopic study on a strain of trypanosoma vivax maintained in cattle (author's transl)].the ultrastructure of the blood forms of trypanosoma vivax from its natural host, cattle, is described. the pellicula, consisting of an unit membrane with a superimposed surface coat, the structure and attachment of the flagellum and the sub-pellicular microtubules showed the usual structural and organizational features. cell organelles and cytoplasmic inclusions such as cell nucleus, mitochondria, kinetoplast, golgi-complex, endoplasmic reticulum and membrane-isolated vacuoles, which occur in t ...19751145722
isoenzymes of two aminotransferases among trypanosoma vivax in nigerian cattle.during a period of three months, thin-layer starch-gel electrophoresis was used to examine the isoenzymes of alanine and asparate aminotransferases from samples of t. vivax collected from naturally infected nigerian cattle. experimentally infected cattle sheep and goats were also studied. three patterns, termed sets 1,2 and 3, differed in both enzymes. the stability of the enzyme patterns was generally confirmed in experimental animals. the results are discussed in relation to subspeciation in t ...19751155995
[current status of bovine haemoparasitic diseases in martinique (french west indies)].a serological survey using indirect immunofluorescence (ifat) for bovine babesiosis (babesia bovis and b. bigemina) and card test for anaplasmosis, indicates that these haemoparasites are widespread in martinique. the high prevalences (62% for b. bovis, 52% for b. bigemina and 43% for anaplasma marginale) lead to the hypothesis of an unstable epizootic situation for these three haemoparasitic diseases. however, the number of smears examined was too low to evaluate their clinical incidence. both ...19921298026
trypanosomiasis in the black rhinoceros (diceros bicornis linnaeus, 1758).a black rhinoceros (diceros bicornis) moved from a tsetse-free to a tsetse-infested area in kenya was monitored for two months following translocation. the animal acquired a trypanosoma vivax infection from natural tsetse challenge, but survived without requiring treatment with trypanocides. the infection was characterised by moderately high parasitaemia, with symptoms of anaemia, leukopaenia and thrombocytopaenia. although confirmed to be t. vivax through deoxyribonucleic acid hybridisation and ...19921305862
trypanosomiasis control in boran cattle in kenya: a comparison between chemoprophylaxis and a parasite detection and intravenous treatment method using isometamidium chloride.two methods of trypanosome control in boran cattle kept under very high trypanosomiasis risk were compared: the traditional intramuscular isometamidium chloride prophylaxis with a parasite detection and intravenous isometamidium chloride treatment method. the results were related to a control group under diminazene aceturate treatment. isometamidium chloride at 0.25 mg/kg as routinely used by the ranch was of little benefit by either method, with breakthrough infections occurring as early as one ...19921306914
a light and electron microscopic study of changes in blood and bone marrow in acute hemorrhagic trypanosoma vivax infection in calves.eleven 6-month-old calves were tsetse fly challenged with a stock of trypanosoma vivax (il 2337) that causes hemorrhagic infection. the calves were randomly euthanatized every 4 to 6 days; two other calves served as controls. peripheral blood changes included anemia, thrombocytopenia, and an initial leukopenia. later in the course of infection, leukocytosis associated with lymphocytosis and neutropenia developed. moderate reticulocytosis (highest mean count 3.6 +/- 3.7%, maximum count 9.4%) acco ...19921348380
maternal antibodies in n'dama calves kept under natural trypanosomiasis risk in the gambia. 19921352635
improvement of the production of trypanosoma vivax antigens.an improved technique for the production of trypanosoma vivax antigen from infected cattle is described. this technique is based upon 1. the application of immunosuppressive drug, 2. the isolation of trypanosomes by centrifugation, and 3. the clearing of the trypanosome suspension from non sedimented blood cells by an anti-serum against bovine blood cells, raised in rabbits.19751189022
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%. ...19921359753
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 ...19921360196
studies on trypanosoma vivax: the infectivity of cyclically and mechanically transmitted ruminant infections for mice and rats. 19761010669
the effect of t. vivax infection in west african dwarf goats on energy and nitrogen metabolism.to investigate how t. vivax affects metabolism in dwarf goats, nine wethers (infection group) given alfalfa pellets ad libitum were infected intravenously and food intake was recorded up to 49 days after infection in the infection group and in the control group (n = 9). controls received the same diet, ad libitum before infection and in restricted amounts after infection in order to obtain similar intakes in the two groups. digestible organic matter intake (domi) and nitrogen balance (nb) were d ...19921413447
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: ...19921496781
serum proteins, blood and plasma volumes in experimental trypanosoma vivax infections of sheep and goats.measurements of blood and plasma volumes using 131i-albumin, and of red cell volume using 51cr in goats and sheep infected with trypanosoma vivax for 1 to 2 months (at which time the anaemia was severe) showed statistically significant increases in blood volume (29 per cent and 57 per cent) and plasma volume (44 per cent and 59 per cent), and decreases in red cell volume per kilogram body weight (49 per cent and 50 per cent) in goats and sheep respectively. total serum proteins and gamma globuli ...19761258150
trypanosoma vivax: linkage of the mini-exon (spliced leader) and 5s ribosomal rna genes. 19921579506
research into the relative importance of tabanidae (diptera) in mechanical disease transmission. iv. a contribution to the epidemiology of bovine trypanosomiasis in africa.the incidence of trypanosomiasis was studied in a herd of dairy cattle near dar es salaam over a period of 4 months. the apparent density of tsetse flies and prevalence of various species of tabanidae were measured. there was no statistical correlation between the disease incidence and the seasonal occurrence of tabanidae. although anaplasmosis was concurrently transmitted by tabanus taeniola on an economically significant scale in this herd and there was a high incidence of trypanosoma vivax in ...1976996931
spliced leader rna sequences of trypanosoma rangeli are organized within the 5s rrna-encoding genes.the spliced leader rna(sl rna)-encoding genes of the salivarian new world trypanosome, trypanosoma rangeli, are organized within the 5s rrna tandem repeats. each repeat contains genes encoding an sl rna and a 5s rrna in the same orientation of transcription. this sl-5s organization is also present in the african trypanosome, trypanosoma vivax. a similar association of sl and 5s genes has been observed in some nematodes, but has not been described previously in trypanosomatids.19921572544
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 ...19921355307
[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 ...19911665576
effect of rna secondary structure and modified bases on the inhibition of trypanosomatid protein synthesis in cell free extracts by antisense oligodeoxynucleotides.every messenger rna from leishmanias and trypanosomes has at its 5' end a conserved region termed the mini-exon sequence which, however, varies from species to species. in a systematic study mrnas from trypanosoma brucei, trypanosoma vivax, and leishmania enriettii were translated in cell-free extracts in the presence of oligodeoxynucleotides complementary to part of the mini-exon sequence. the affinity of the same oligonucleotides for target and non-target mrnas was determined by thermal elutio ...19901697674
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 ...19911763478
control of tsetse and trypanosomiasis transmission in uganda by applications of lambda-cyhalothrin.the pyrethroid insecticide lambda-cyhalothrin was evaluated in field trials against glossina f.fuscipes and sleeping sickness transmission in iyolwa sub-county, tororo district, uganda. the insecticide was applied selectively to the resting-sites of tsetse, by bush-spraying, using 10% wettable powder (10wp) formulation at an application rate of 11.6 g a.i./ha over an area of 28 km2, or by a 2% electrodyn formulation (2ed) applied at 0.9 g a.i./ha over 30 km2. in a third trial area of 32 km2, 215 ...19911768891
trypanosoma vivax in glossina palpalis gambiensis do not appear to affect feeding behaviour, longevity or reproductive performance of the vector.feeding behaviour of glossina palpalis gambiensis vanderplank infected with trypanosoma vivax ziemann was studied and compared with that of uninfected control tsetse. the parameters measured were: total number of probes into the ear-skin of rabbits; rate of bloodmeal engorgement; weight of freshly ingested blood; survival; and mean weight of pupae. the results showed that the rosettes of t.vivax parasites in the labrum did not interfere with the feeding behaviour of the vectors. furthermore, mea ...19911768899
the decline of a glossina morsitans submorsitans belt in the egbe area of the derived savanna zone, kwara state, nigeria.in the the early 1970s the egbe area of nigeria was known to be one of high trypanosomiasis risk, with four glossina species g. morsitans submorsitans newstead, g.longipalpis wiedemann, g.palpalis palpalis robineau-desvoidy and g.tachinoides westwood present. grazing by fulani pastoralists used to be short-term and only in the dry season. in recent years these pastoralists have grazed their cattle in the area throughout the year and this has prompted a reappraisal of the tsetse situation. tsetse ...19911768900
transmission of south american trypanosoma vivax by the neotropical horsefly tabanus nebulosus. 19911678579
in vitro assessment of isometamidium chloride susceptibility of trypanosoma vivax bloodstream forms. 19911805217
the course of experimental trypanosoma vivax infection in uda sheep.the course of experimental trypanosoma vivax infection in eight uda rams was studied. all the infected animals became parasitaemic 2 days post-inoculation and remained so throughout the study period. a three-phase disease pattern was recognized, i.e. acute, subacute and chronic stages lasting 17-85 days. the disease was characterized by fever and a terminal decrease in rectal temperature despite an increase in parasitaemia with time for rams with acute and subacute infections. mean weight loss w ...19911882495
an outbreak of trypanosomosis on the jos plateau, nigeria. 19911796524
effect of trypanosoma vivax infection on body temperature, feed intake, and metabolic rate of west african dwarf goats.thirty-two mature dwarf goats weighing between 16 and 30 kg (22.7 +/- 3.7, sd) were used to study the effect of trypanosoma vivax infection on rectal temperature (rt), feed intake (dmi), and metabolic rate. sixteen of the goats were infected intravenously with 14 x 10(6) t. vivax each; the 16 others served as controls. animals were fed at about 1.1 times maintenance. heat production was measured from 1 wk preinfection to 6 wk postinfection. from data on successive 9-min periods, heat production ...19911682294
comparative study of clinical signs, haematology and prevalence of trypanosomiasis in holstein friesian and white fulani zebu cattle exposed to natural infection in a rain forest zone of nigeria.a comparison of the symptomatology, haematology and prevalence of trypanosomiasis in holstein friesian and white zebu cattle exposed to natural infections on a ranch in a rain forest zone of nigeria is presented. 23 (44%) of the adult friesians had trypanosome infections with a generally heavy parasitaemia. infection was light in the friesian calves and the zebus with infection rates of 2 (6.9%) and 3 (15%) respectively. trypanosoma vivax was the sole species encountered on the farm. there was a ...19911888077
[experimental infection of the guyanese zebu with trypanosoma vivax].the guyanese strain of trypanosoma vivax is pathogenic for the local brahman zebu; the experimental infection of 19 one-year old cattle was followed by a moderate and transitory fever, a drop in packed cell volume (pcv) and a quick and marked weight loss of 10 to 17 kg one month after as compared to the 16 non-infected animals. other symptoms were associated with the parasitaemia: diarrhoea, swollen haematic glands on the neck and the flank, lachrymation, weakness. despite a trypanocidal treatme ...19901983439
differential expression of a family of putative adenylate/guanylate cyclase genes in trypanosoma brucei.the expression site for the variant surface glycoprotein (vsg) gene of trypanosoma brucei contains several genes of unknown function (esags, for expression site-associated genes). among these, esag 4 shows homology to eukaryotic adenylate/guanylate cyclase genes, in the region encoding the presumptive enzyme catalytic domain. this gene belongs to a family of related sequences, and hybridizes to the genomic dna of other trypanosomatids, such as trypanosoma congolense, trypanosoma vivax and trypan ...19901982555
studies on trypanosoma vivax: transmission of mouse infective t. vivax by tsetse flies. 1976965147
axenic in vitro cultivation of trypanosoma vivax trypomastigote forms.cultures of trypanosoma vivax stocks were initiated with tsetse-derived metacyclics and with organisms isolated from mouse blood. they were propagated as trypomastigote forms at 35 degrees c initially in the presence of bovine endothelial cells. all stocks were subsequently adapted to axenic culture conditions. the standard medium consisted of hepes-buffered mem with 1% mem non-essential amino acids, containing 2 mm l-glutamine, 1 mm sodium pyruvate, 100 iu/ml penicillin, 100 micrograms/ml strep ...19912052856
the effect of isometamidium chloride on insect forms of drug-sensitive and drug-resistant stocks of trypanosoma vivax: studies in vitro and in tsetse flies.isometamidium chloride-resistant and -sensitive trypanosoma vivax insect forms were continuously propagated in vitro without feeder-layer cells in a semi-defined liquid medium at 27 degrees c. the effect of isometamidium chloride (samorin) on t. vivax was assessed by monitoring the viability of epimastigotes and the production of metacyclic forms. populations of insect forms of t. vivax stock il 1392 and clone il 3185 showed reduced growth and died after 10 days when cultivated in the presence o ...19911994365
differences in sensitivity of kenyan trypanosoma vivax populations to the prophylactic and therapeutic actions of isometamidium chloride in boran cattle.isometamidium chloride was administered as a single prophylactic dose of 0.5 mg kg-1 body weight to each of 10 boran (bos indicus) steers. at monthly intervals following drug administration, groups of five cattle each were challenged with one of two different trypanosoma vivax populations transmitted by infected glossina morsitans centralis; one with a stock (il 2982) from galana, kenya and the other with a stock (il 2986) from likoni, kenya. prophylaxis was afforded for less than one month agai ...19912038768
effect of trypanosoma vivax infection on energy and nitrogen metabolism of west african dwarf goats.a study was conducted using 32 mature 22-kg west african dwarf goats to measure the effect of trypanosoma vivax infection on energy and nitrogen metabolism. sixteen goats were infected intravenously with 14 x 10(6) t. vivax. sixteen control goats were sham-injected. digestibility and metabolizability of energy and n balance were measured for each goat. heat production and energy balances were measured per treatment group from 1 wk before infection to 6 wk after infection. goats were fed alfalfa ...19912071524
use of the dot enzyme-linked immunosorbent assay with isolated anaplasma marginale initial bodies for serodiagnosis of anaplasmosis in cattle.isolated anaplasma marginale initial bodies were successfully used in a dot elisa for rapid detection of antibodies to anaplasma organisms. the enzyme immunoassay used only 25 ng of antigen dotted onto nitrocellulose disks. antigen-antibody complexes were detected by use of alkaline phosphatase-conjugated protein a, and reactions were read visually after addition of a precipitable, chromogenic substrate. the test allowed the processing of multiple sera, either for screening or for titer determin ...19902240769
small ruminant trypanosomiasis in guyana--a preliminary report.trypanosomes identified as trypanosoma vivax were found infecting nine sheep (4.6%) and one goat (1.3%) on four of 11 farms surveyed on coastal guyana. animals sampled on another farm situated in the rupununi savannahs gave negative results. haematological techniques preferred for studies of this nature were the haematocrit centrifuge technique (hct) and the thick blood smear technique.19902306609
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 ...19902163493
[ticks and hemoparasitic diseases in cattle in senegal. iv. the southern sudan area].the authors report on the results of an investigation on ticks and hemoparasitoses of cattle, sheep and goats in the south sudanian area of senegal. systematic routine dipping against ticks of cattle, 40 sheep and 40 goats was set during 15 months, with a view to determine the population dynamics together with an acurate localization of the different species concerned. the following parasites were collected from these ruminants: amblyomma variegatum, boophilus geigyi, hyalomma truncatum, h. m. r ...19902218038
the development of an enzyme-linked immunosorbent assay for trypanosoma vivax and its use in a seroepidemiological survey of the eastern caribbean basin.an enzyme-linked immunosorbent assay (elisa) for igg antibodies against a south american (new world) strain of trypanosoma vivax was developed and used for mass screening of cattle from 20 islands in the eastern caribbean basin. the sensitivity and specificity of antigens prepared from a bovine-derived field strain and a murine-adapted laboratory strain of t. vivax, both of new world origin, were compared using an indirect fluorescent antibody (ifa) test, and an antigen prepared from the murine- ...19902312226
antigenic relatedness of stocks and clones of trypanosoma vivax from east and west africa.the antigenic relationships of 7 stocks and 7 clones of trypanosoma vivax from east and west africa were compared by immune lysis. sera from goats infected with different stocks and clones of t. vivax, collected on days 40 and 80 after infection, were used in the immune lysis test with homologous and heterologous stocks and clones of trypanosomes. sera from infected cattle were included to compare stocks and clones from kenya. the parasites that were used as antigen in the immune lysis tests wer ...19902314924
parasite-specific antibody responses of ruminants infected with trypanosoma vivax.sera from goats and cattle that were infected with two trypanosoma vivax clones (ildat 1.2 and ildat 2.1) derived from different stocks were analysed for antibody activity against the variable surface glycoproteins (vsgs) of the infecting clones by enzyme-linked immune assays (elisa) and immune lysis. to obtain purified vsg, lysed trypanosomes were separated on dodecyl sulphate-polyacrylamide gels. the gels were copper stained and the vsg protein band was excised from the gel. after destaining, ...19902314930
haemorrhagic pancarditis in cattle infected with trypanosoma vivax.haemorrhagic pancarditis has been studied microscopically and ultrastructurally. haemorrhages, oedema, mononuclear cell infiltration, degeneration, fragmentation, atrophy and lysis of myofibres, and extravascular localisation of the parasite were observed.19902316175
studies on trypanosoma vivax: infectivity and serial maintenance of natural bovine isolates in mice. 1976965146
a drug incubation infectivity test (diit) for assessing resistance in trypanosomes.blood stream forms of drug-resistant and sensitive trypanosoma brucei brucei, trypanosoma brucei evansi and trypanosoma vivax were incubated in a liquid medium for 24 h at 37 degrees c in the presence of various concentrations of diminazene aceturate (berenil) or isometamidium chloride (samorin), and assayed for infectivity in mice. whereas the infectivity to mice of all samorin-sensitive trypanosomes was decreased after incubation with 1 ng samorin ml-1, the samorin-resistant stocks remained in ...19902316178
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 ...19911686140
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 ...19902321260
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 ...19902343522
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 ...19902343531
metacyclogenesis of trypanosoma vivax in vitro: attachment to chitosan gel. 19902383099
effect of chemotherapy on elevated ejaculation time and deteriorated semen characteristics consequent to bovine trypanosomiasis.the effect of the trypanocidal drug novidium on elevated ejaculation time and deteriorated semen characteristics was studied in zebu cattle infected with t. vivax and t. congolense. two groups, comprising six bulls per group, were infected with trypanosoma vivax or trypanosoma congolense while three bulls served as controls. chemotherapy was carried out 12 weeks post-infection on three bulls from each group, leaving three bulls untreated while three bulls served as uninfected controls. blood sam ...19902397378
platelet aggregation inhibition in trypanosoma vivax infection of sheep.we have investigated in vitro platelet aggregation in platelet rich plasma from trypanosoma vivax infected and control sheep using the dual channel payton aggregometer. final concentrations of the following inducing agents were used: 1.2 um adp, 6.2 ug collagen, 1.2 ug ristocetin and 1 u thrombin. these showed that there was a significantly reduced aggregation of platelets from infected sheep (13.4 +/- 1.1 pc at week 3 post infection when compared with control sheep prp 95.0 +/- 1.0pc; p less th ...19902397492
comparative structural analysis of calmodulins from trypanosoma brucei, t. congolense, t. vivax, tetrahymena thermophila and bovine brain.calmodulin is an intracellular calcium receptor protein utilized extensively by eukaryotic cells to mediate responsiveness to calcium signals. the present study evaluates the effects on protein structure of amino acid substitutions in trypanosome calmodulin. calmodulin conformation, hydrophobicity and antigenic determinants are compared among trypanosoma brucei, trypanosoma congolense, trypanosoma vivax, tetrahymena thermophila and bovine brain. trypanosome calmodulin differs from brain and tetr ...19852417117
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 ...19911991468
[tabanus importunus, experimental mechanical vector of trypanosoma vivax in french guiana].the pathogen of american bovine trypanosomiasis trypanosoma vivax was transmitted between zebu bull calves by blood meal interruption and immediate resumption of female tabanus importunus horse flies. transmission was achieved by 44 transfers from the donor animal to the recipient animal carried out from 8 to 10 days after experimental inoculation of the donor animal. parasitemia was detected in the recipient animal 10 days after transfer beginning.19902344135
effect of trypanosoma vivax infection on semen characteristics of yankasa rams.twelve yankasa rams aged between 2 1/2 and 3 years with good semen characteristics were used in this 15-week study. six rams were infected with trypanosoma vivax, while six served as controls. the infected rams developed chronic trypanosomosis accompanied by fluctuating pyrexia, lethargy, anaemia, scrotal oedema and cachexia. there was a drastic and progressive deterioration in semen quality in all infected rams manifested by a decrease in volume or cessation of semen production, oligozoospermia ...19921361406
a comparison of the isoenzymes of trypanosoma (duttonella) vivax isolates from east and west africa.the genetic diversity in 13 stocks and clones of trypanosoma vivax from east and west africa was compared by isoenzyme analysis. the ugandan and west african stocks and clones showed a very high degree of genetic similarity to each other but they differed from the kenyan stocks and clones. two haemorrhagic stocks, il 2337 (galana, kenya) and il 3067 (bamburi, kenya), showed a high degree of similarity in enzyme banding patterns in electrophoresed preparations. one of the kenyan stocks, m1d 627, ...19902358323
[globular resistance in bovine erythrocytes].an analysis of red blood cells resistance has been conducted by exposing red corpuscles of zebu, baoule and metis zebu x baoule, to different saline concentrations. the statistical results show no sex influence for all breeds. in zebu, there is a difference according to the type of hemoglobin concerned. the last ones differ also from these in taurine and metis. the data analysis were realised by calculating the mean of hemolysis percentages for all samples, as with nacl concentrations in respect ...19892485552
antigenic variation during trypanosoma vivax infections of different host species.the sequence of appearance of specific lytic activity against more than 20 variable antigen types (vats) of trypanosoma vivax in the serum of 27 animals belonging to 5 species has been examined. for each host species there was a characteristic course of infection, with differences in height and duration of parasitaemia and in pathogenicity. the sequence of antigenic variation was similar in all host species, with some vats consistently eliciting response more rapidly than others. the predominant ...19862421230
trypanosoma vivax: disseminated intravascular coagulation in cattle.five crossbred cattle infected with trypanosoma vivax (likoni) by glossina morsitans developed capillary haemorrhages at the onset of parasitaemia, followed by the presence of occult blood in faecal samples and eventually melena. two animals required treatment to survive, on days 13 and 38 respectively. the other three animals cleared their parasitaemias without treatment. packed cell volume (pcv) levels decreased in all animals to levels ranging from 7.5 to 17%. relapse in a treated animal init ...19892619392
antigen-detection enzyme immunoassays for the diagnosis of trypanosoma vivax, t. congolense and t. brucei infections in cattle.species-specific monoclonal antibodies against trypanosoma vivax, t. congolense and t. brucei were used to develop antigen-capture enzyme-linked immunosorbent assays (antigen-elisa) for the diagnosis of bovine trypanosomiasis. each assay was subsequently used for the detection of species-specific circulating antigens in sera of cattle experimentally infected by tsetse transmission. in t. vivax and in t. congolense-infected animals, circulating antigens were detected as early as 10-12 days post-i ...19892617031
natural and acquired resistance to trypanosoma vivax in cattle.zebu x european (z x e) crossbred cattle suffered a more severe course of disease than boran cattle when infected with trypanosoma vivax (likoni) by glossina morsitans. all z x e animals in this study required berenil treatment while all borans self-cured the infection without treatment. the more severe disease in z x e animals was characterized by longer periods of patent infection and fever, more severe anaemia and greater likelihood of haemorrhage. cattle previously infected and cured with be ...19892619393
babesia equi and trypanosoma vivax infections in donkeys.six donkeys (equus asinus) were purchased locally. to screen them before and during trypanosoma vivax infection, thin and thick blood smears, temperature, haematocrit centrifuge technique (hct), packed cell volume (pcv), white blood cell counts, and indirect immunofluorescent antibody test (ifat) were done for babesia equi. for the ifat, an anti-horse conjugate was used. in spite of patent b. equi or t. vivax parasitaemia, the donkeys' temperatures remained below 38.5 degrees c; pcv was depresse ...19892626573
leucopenia in trypanosoma vivax infection of sheep.experimental trypanosoma vivax infection of sheep produced a moderate leucopenia associated with a lymphopenia and eosinopenia. the total white blood cell counts of adult mice were not significantly depressed when inoculated with plasma from t. vivax-infected sheep. these observations suggested that the plasma of the infected sheep did not have a factor which could depress leucopoiesis in vivo.19892626575
recent studies of the biology of trypanosoma vivax.recent biological investigations of the african trypanosomes have been moving away from their previous preoccupation with the phenomenon of antigenic variation. the feeling has arisen that antigenic variation, as demonstrated by the trypanozoon and nannomonas subgenera of trypanosomes, is too extensive, the number of serodemes too large and the coexistence of different species in many areas too complicated, to allow any immunoprophylaxis based on antibodies to variable antigens. this is, of cour ...19892683616
occurrence of human serum-resistant trypanosoma congolense in goats and sheep in nigeria.an assessment of the role of dogs, goats and sheep as reservoir hosts of african trypanosomes infective for humans (sleeping sickness) was carried out in nigeria during a 2-year study period. twelve stocks of trypanosoma (trypanozoon) brucei, 10 stocks of trypanosoma congolense and 11 stocks of trypanosoma vivax were isolated from a total of 699 animals, comprising 286 sheep, 221 goats and 192 dogs. the potential infectivity of the isolates for man was tested in vitro using the blood incubation ...19892741299
detection of antibodies to platelets and erythrocytes during infection with haemorrhage-causing trypanosoma vivax in ayrshire cattle.ayrshire cattle, which were infected with a stock of trypanosoma vivax from galana, kenya, which produced haemorrhagic disease, were examined for the presence of antibodies to erythrocytes and platelets. antibodies to normal erythrocytes and platelets were detected in the plasma of infected animals using the enzyme-linked immunosorbent assay (elisa). the antibodies were detectable following the first peak of parasitaemia (10-15 days after infection) and antibody activity was maximal 30-35 days a ...19892503920
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