Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
nutritional stress affects the tsetse fly's immune gene expression.tsetse-transmitted trypanosomiasis poses a serious threat to human and animal health in sub-saharan africa. the majority of tsetse flies (glossina spp.) in a natural population will not develop a mature infection of either trypanosoma congolense or trypanosoma brucei sp. because of refractoriness, a phenomenon that is affected by different factors, including the tsetse fly's immune defence. starvation of tsetse flies significantly increases their susceptibility to the establishment of a trypanos ...200919712150
comparative histopathology of the lymph nodes, spleen, liver and kidney in experimental ovine trypanosomosis.the infection of yankassa rams with three important trypanosome species affecting livestock, namely, trypanosoma congolense, t. vivax and t. bruceiproduced both acute and chronic fatal conditions. chronic infections were induced in the three infections by the application of subcurative doses of diaminazene aceturate (berenil). pathological changes in the infected animals included splenomegaly and hepatomegaly which were more pronounced in acute than in chronic t. congolense infection. however, t ...200921344787
divergent antimicrobial peptide (amp) and acute phase protein (app) responses to trypanosoma congolense infection in trypanotolerant and trypanosusceptible cattle.african animal trypanosomiasis (aat) is endemic across sub-saharan african and is a major constraint to livestock production. the ability of certain cattle breeds to remain productive despite infection is known as trypanotolerance; however, the underlying immune mechanisms contributing to this trait remain poorly understood. antimicrobial peptides (amps) and acute phase proteins (apps) are evolutionarily conserved effector molecules of the innate immune system that have important roles in the re ...200919889461
[eco-distribution and trypanosoma infection of glossina palpalis palpalis in the banco forest of and its relics, abidjan (côte d'ivoire)].in order to implement an anti-vector programme in the suburb of abidjan (côte d'ivoire), investigations were conducted to assess the tsetse fly densities as well as infection with trypanosomes. catches were carried out during the rainy season and dry season with vavoua traps laid during four consecutive days in different sites (banco forest, abidjan zoological park, area of the university of abobo-adjamé). one species of tsetse fly (glossina polpalis palpalis) and two species of trypanosomes (tr ...200920092060
current trends in follow-up of trophoblastic function in ruminant species.during the pregnancy of ruminants, different hormones and proteins are secreted by placenta or corpus luteum allowing the follow up of gestation. among them, progesterone (p4) and pregnancy-associated glycoproteins (pag) were proposed as laboratory tools to establish or to confirm pregnancy diagnosis. in last years, pag assay also provided useful information for researchers working in programs focused on the follow up of trophoblastic function. concentrations of pag appeared as altered after the ...200819261972
study of bovine trypanotolerance by whole transcriptome analysis.african trypanosomiases are parasitic diseases transmitted by tse-tse flies, considered as the main sanitary obstacle to animal production development in sub-saharan africa. however, if trypanosomiases have dramatic consequences on zebu (bos indicus) populations, they have a weaker impact on the western african taurine (bos taurus), which is known to be naturally tolerant to trypanosome infection. mechanisms governing this trypanotolerant trait are still poorly understood, but today, recent post ...200819120177
immunodiagnosis of bovine trypanosomiasis in anambra and imo states, nigeria, using enzyme-linked immunosorbent assay: zoonotic implications to human health.the prevalence of trypanosomiasis was studied in cattle, being a major source of animal protein in nigeria, thus, a very likely means of spread of human african trypanosomosis (hat).200819248656
acute phase response in mice experimentally infected with trypanosoma congolense: a molecular gauge of parasite-host interaction.mice infected with trypanosoma congolense developed a severe anaemia 1 week after infection, which persisted till treatment with diminazine aceturate when the packed cell volume (pcv) recovered to pre-infection levels. this was accompanied by a marked increase in the plasma levels of the acute phase proteins (app), serum amyloid p-component (sap) and haptoglobin (hp). the initial peak levels of hp and sap were attained 7 and 12 days post-infection (dpi), respectively. thereafter sap levels decre ...200818063482
prevalence of bovine trypanosomosis and trypanocidal drug sensitivity studies on trypanosoma congolense in wolyta and dawero zones of southern ethiopia.cross-sectional studies were conducted in tsetse and non-tsetse-controlled areas of the southern nation nationalities and peoples regional state (snnprs) of ethiopia to determine the prevalence of bovine trypanosomosis as well as drug sensitivity tests on trypanosoma congolense in both naturally and experimentally infected cattle and mice, respectively. a total trypanosome prevalence of 4.8% (95% ci: 1.8-7.5) and 20.4% (95% ci: 14-26.8) were recorded in the tsetse-controlled study area of humbo ...200818207329
regulatory t cells prevent control of experimental african trypanosomiasis.african trypanosomes are single-cell, extra-cellular blood parasites causing profound immunosuppression. susceptible balb/c mice infected s.c. into a footpad with 10(4) trypanosoma congolense die with fulminating parasitemia within 10 days. we injected balb/c mice 2 days before such an infection with different doses of a depleting mab specific for cd25, a surface marker of regulatory t cells (tregs). pretreatment with a low, optimal dose of anti-cd25 resulted in a dramatic effect, in that the in ...200818250461
experimental expansion of the regulatory t cell population increases resistance to african trypanosomiasis.inflammatory responses mounted to eliminate parasites can be lethal if not counterbalanced by regulatory responses protecting the host from collateral tissue damage. here, we show that the maintained inflammation associated with tissue damage, anemia, and reduced survival of trypanosoma brucei-infected mice correlates with the absence of the expansion of the regulatory t (t(reg)) cell population. induction of t(reg) cell expansion via cd28 superagonist antibody treatment in these mice down-regul ...200818627271
semen sialic acid surge and modulation of alpha-l-fucosidase activity: possible link to loss in reproductive capacity during trypanosomiasis.the profiles of semen sialic acid and the enzyme alpha-l-fucosidase were studied in rams undergoing chronic infection by trypanosoma congolense. our data showed a significant surge in the level of sialic acid with parasitaemia. the pattern followed a polynomial function we had reported for erythrocyte sialic acid in mice undergoing acute infection by t. congolense. the activity of the enzyme alpha-fucosidase decreased progressively with approximately 60% decrease at the end of the 14 weeks of in ...200817487932
trypanosomosis in the gambia: prevalence in working horses and donkeys detected by whole genome amplification and pcr, and evidence for interactions between trypanosome species.the gambia has an increasing population of equidae largely used for agriculture and transportation. a review of cases at the gambian horse and donkey trust (ghdt) indicated that a common reason for presentation is a poorly defined medical condition often attributed to trypanosomosis. there are few reports describing the prevalence or the range of clinical signs associated with infection with different species of trypanosomes in horses and donkeys, but given the importance of these animals, the r ...200818289378
does isometamidium chloride treatment protect tsetse flies from trypanosome infections during sit campaigns?african animal trypanosomosis is a major pathological constraint to cattle breeding across 10 million km2 of sub-saharan west african countries infested by tsetse flies, their cyclic vectors. the release of sterile males (sterile insect technique [sit]) is a potentially important control technique aimed at eliminating the vectors. prior to release, tsetse are generally treated with isometamidium chloride, a trypanocide, to prevent them from transmitting parasites. the present study investigated ...200818498613
molecular detection of tick-borne protozoal and ehrlichial infections in domestic dogs in south africa.a total of 1,138 blood specimens were collected over a 6-year period (2000-2006) from domestic dogs in south africa. specimens from domestic dogs were obtained from the onderstepoort veterinary academic hospital (ovah) in pretoria, the society for the prevention of cruelty to animals (johannesburg, durban, east london and bloemfontein) and private practices from four provinces (gauteng, mpumalanga, kwazulu-natal and western cape). all specimens were screened for babesia, theileria, hepatozoon an ...200818502588
interleukin-12p70 deficiency increases survival and diminishes pathology in trypanosoma congolense infection.to determine the immunological role played by interleukin (il)-12 family members in trypanosoma congolense infection, il-12p35(-/-), il-12p40(-/-), and il-12p35(-/-)/p40(-/-) mice were used. while the latter 2 strains lack all il-12 homologues, il-12p35(-/-) mice still produce il-12p80 homodimers and il-23. compared with wild-type mice, all infected il-12-deficient mouse strains showed prolonged survival, whereas parasitemia levels were unaltered. interferon (ifn)-gamma production in il-12-defic ...200818816189
identification and molecular characterization of a novel stage-specific surface protein of trypanosoma congolense epimastigotes.the cattle pathogen trypanosoma congolense expresses life cycle stage-specific surface molecules involved in adaptation to different host and vector environments. here we report the discovery and molecular characterization of a novel stage-specific gpi-anchored surface glycoprotein that is selectively expressed in the epimastigote (emf) life cycle stage of t. congolense. culture supernatants of emf but not of procyclic culture forms (pcfs) promoted adhesion of pcf parasites in an in vitro assay. ...200818571746
effect of cd4+cd25+ t cell-depletion on acute lethal infection of mice with trypanosoma congolense.despite the immense socio-economic repercussions of african trypanosomosis (at), there is currently no effective control measure against the disease. characterization of mechanisms governing resistance and/or susceptibility to at could suggest interventions that might lead to more effective disease control. the present study was designed in an attempt to address the possible role of cd4+cd25+ t cells during an acute lethal infection of mice with trypanosoma congolense, the causative agent of at ...200818772548
prevalence of bovine trypanosomosis in central mozambique from 2002 to 2005.the study is the result of analyzing 16895 blood smears of cattle collected at 180 sites in the provinces of manica, sofala, zambézia and tete in mozambique. of the blood smears 73.9% were from manica, 11.8% from tete, 8.5% from sofala and 5.8% from zambézia; 75.6% of these were collected from smallholder cattle. infections with trypanosomes were highest in smallholder cattle from sofala province with 36.8% of the 872 blood smears examined positive for trypanosomes, and lowest in cattle of comme ...200818575067
distinct roles of apolipoprotein components within the trypanosome lytic factor complex revealed in a novel transgenic mouse model.humans express a unique subset of high-density lipoproteins (hdls) called trypanosome lytic factors (tlfs) that kill many trypanosoma parasite species. the proteins apolipoprotein (apo) a-i, apol-i, and haptoglobin-related protein, which are involved in tlf structure and function, were expressed through the introduction of transgenes in mice to explore their physiological roles in vivo. transgenic expression of human apolipoprotein l-i alone conferred trypanolytic activity in vivo. coexpression ...200818606856
a systematic, data-driven approach to the combined analysis of microarray and qtl data.high-throughputtechnologies inevitably produce vast quantities of data. this presents challenges in terms of developing effective analysis methods, particularly where the analysis involves combining data derived from different experimental technologies. in this investigation, a systematic approach was applied to combine microarray gene expression data, quantitative trait loci (qtl) data and pathway analysis resources in order to identify functional candidate genes underlying tolerance to trypano ...200818817316
t cells and immunopathogenesis of experimental african trypanosomiasis.summary: african trypanosomes are pathogens for humans and livestock. they are single-cell, extra-cellular parasites that cause persistent infections of the blood and induce profound immunosuppression. here, we review recent work on experimental african trypanosomiasis, especially infections with trypanosoma congolense, in mice with regard to mechanisms of immunosuppression and immunopathology. the center of the immunopathology is the t-cell-independent production of antibodies to the variant su ...200818837780
prevalence and source of trypanosome infections in field-captured vector flies (glossina pallidipes) in southeastern zambia.the prevalence of trypanosome infections in tsetse flies, glossina pallidipes, collected from chiawa and chakwenga in zambia with endemic trypanosomosis was assessed by polymerase chain reaction (pcr). out of the 550 g. pallidipes, 58 (10.5%) flies were found to harbor trypanosome dna. infection rates of tsetse with trypanosoma vivax universal, trypanosoma congolense savannah, t. congolense forest and t. congolense kilifi were 4.2% (23/550), 4.7% (26/550), 1.1% (6/550) and 1.6% (9/550), respecti ...200818840966
five-fold increase in trypanosoma congolense isolates resistant to diminazene aceturate over a seven-year period in eastern zambia.two groups of trypanosoma congolense isolates collected from cattle in 1996 (n=39) and 2003 (n=38) in the eastern province of zambia were analyzed by bcli-pcr-rflp to assess the evolution of diminazene aceturate (da) resistance over a period of seven years. the results show a significant increase of da resistance in this relatively short period of time. in 1996, among the 39 isolates, 61.5% were found sensitive, 12.8% resistant and 25.7% had a mixed bcli-pcr-rflp profile. in 2004, among the 38 i ...200818993109
investigations on the transmissibility of trypanosoma congolense by the tsetse fly glossina morsitans morsitans during its development in a mammalian host.experiments were conducted to investigate the effect of the developmental stage of a monomorphic t. congolense il1180 strain, in a vertebrate host, on its transmissibility by the tsetse fly glossina morsitans morsitans westwood (diptera: glossinidae). batches of 160 male teneral tsetse flies were given a single bloodmeal on mice infected with this t. congolense strain 4, 5, 6, 7 or 10 days post-infection. the proportion of infected flies in each of those batches showed that the stage of developm ...200818485324
alternatively activated myeloid cells limit pathogenicity associated with african trypanosomiasis through the il-10 inducible gene selenoprotein p.uncontrolled inflammation is a major cause of tissue injury/pathogenicity often resulting in death of a host infected with african trypanosomes. thus, comparing the immune response in hosts that develop different degrees of disease severity represents a promising approach to discover processes contributing to trypanosomiasis control. it is known that limitation of pathogenicity requires a transition in the course of infection, from an ifn-gamma-dependent response resulting in the development of ...200818424738
health management of horses under high challenge from trypanosomes: a case study from serengeti, tanzania.horses kept for recreational riding purposes by a wildlife tourism company in a heavily tsetse fly-infested region of north-western tanzania were systematically monitored to investigate the occurrence, presentation and management of tsetse-transmitted trypanosomosis. during a 23-month period, 18 clinical cases were diagnosed (trypanosoma brucei or trypanosoma congolense were identified) and treated and trypanosomes were implicated of involvement in four deaths. pyrexia consistently aided early d ...200818450381
biphasic survival analysis of trypanotolerance qtl in mice.a marker-assisted introgression (mai) experiment was conducted to transfer trypanotolerance quantitative trait loci (qtl) from a donor mouse strain, c57bl/6, into a recipient mouse strain, a/j. the objective was to assess the effect of three previously identified chromosomal regions on mouse chromosomes 1 (mmu1), 5 (mmu5) and 17 (mmu17) in different genetic backgrounds on the survival pattern following infection with trypanosoma congolense. an exploratory data analysis revealed a biphasic patter ...200818253157
molecular and biochemical characterization of a cathepsin b-like protease family unique to trypanosoma congolense.cysteine proteases have been shown to be essential virulence factors and drug targets in trypanosomatids and an attractive antidisease vaccine candidate for trypanosoma congolense. here, we describe an important amplification of genes encoding cathepsin b-like proteases unique to t. congolense. more than 13 different genes were identified, whereas only one or two highly homologous genes have been identified in other trypanosomatids. these proteases grouped into three evolutionary clusters: tcocb ...200818281598
assessment of the occurrence of trypanocidal drug resistance in trypanosomes of naturally infected cattle in the adamaoua region of cameroon using the standard mouse test and molecular tools.from may to november 2005, a study was carried out to assess the occurrence of trypanocidal drug resistance (dr) in trypanosomes of naturally infected cattle of the adamaoua region of cameroon. two distinct polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) procedures were used together with an allele specific-pcr (as-pcr) and the standardized single-dose mouse test. using the mouse test, 3 of the 13 trypanosoma brucei isolates and all 14 tested trypanosoma congolense ...200818355771
in vitro trypanocidal activity of the anti-helminthic drug niclosamide.only a few drugs are available for chemotherapy of african trypanosomiasis and there is an urgent need for the development of new anti-trypanosomal agents. in this study, the anti-helminthic drug niclosamide was tested for its trypanocidal activity in vitro using culture-adapted bloodstream forms of trypanosoma brucei brucei and trypanosoma congolense. the concentrations of niclosamide to reduce the growth rate by 50% and to kill all cells were in the low- and mid micromolar ranges for t. b. bru ...200818226810
a glycosylphosphatidylinositol-based treatment alleviates trypanosomiasis-associated immunopathology.the gpi-anchored trypanosome variant surface glycoprotein (vsg) triggers macrophages to produce tnf, involved in trypanosomiasis-associated inflammation and the clinical manifestation of sleeping sickness. aiming at inhibiting immunopathology during experimental trypanosoma brucei infections, a vsg-derived gpi-based treatment approach was developed. to achieve this, mice were exposed to the gpi before an infectious trypanosome challenge. this gpi-based strategy resulted in a significant prolonge ...200717785839
age prevalence of trypanosomal infections in female glossina morsitans morsitans (diptera: glossinidae) on the plateau area of eastern zambia.trypanosomal infections in female glossina morsitans morsitans were investigated in an area in the eastern province of zambia between 1992 and 1994. a total of 4416 flies were captured, aged using the ovarian ageing method and screened for trypanosomal infections in both the mouthparts, salivary glands and the midgut. congolense-type infections were identified in 4.8% of the flies. vivax-type and immature infections were identified in 1.8% and 6.8% of the flies, respectively. the prevalence of c ...200717933364
livestock farmers' perception and epidemiology of bovine trypanosomosis in kwale district, kenya.we did cross-sectional surveys in kwale district, kenya to determine the epidemiology of bovine trypanosomosis and livestock owners' perceptions of the disease. the surveys involved relative importance of trypanosomosis, examination of the current disease constraints, current control practices and drug-use patterns. informal meetings were held with farmers and cattle census undertaken. tsetse-fly densities and trypanosomosis prevalences in cattle were determined. a total of 132 farmers were inte ...200717324481
isolation of a 14 kda antigen from taenia solium cyst fluid by hplc and its evaluation in enzyme linked immunosorbent assay for diagnosis of porcine cysticercosis.a fraction with a major band of 14kda was obtained from crude cyst fluid of taenia solium cysticerci by 2-step chromatography. a first fraction isolated by gel filtration (sephacryl s-300 high resolution) was purified using an anion exchange column (mono q hr 5/5) on high performance liquid chromatography. evaluation of the analytic sensitivity of this fraction (f3) was carried out in an antibody enzyme linked immunosorbent assay (ab-elisa-f3) using serum samples from pigs experimentally infecte ...200717101161
point mutations in mitochondrial topoisomerase enzymes of trypanosoma congolense are not involved in isometamidium resistance. 200717123643
effects of exogenous transforming growth factor beta on trypanosoma congolense infection in mice.the socioeconomic implications of trypanosomosis in sub-saharan africa and the limitations of its current control regimes have stimulated research into alternative control methods. considering the pro- and anti-inflammatory properties of transforming growth factor beta1 (tgf-beta1) and its potential to enhance immunity against protozoan parasites, we examined the effects of intraperitoneally delivered tgf-beta1 in c57bl/6 mice infected with trypanosoma congolense, the hemoprotozoan parasite caus ...200717261602
bovine trypanosomosis in three districts of east gojjam zone bordering the blue nile river in ethiopia.bovine trypanosomosis is a serious constraint to agricultural production in extensive areas of ethiopia.200719734612
trypanosoma congolense infections: mhc class ii-restricted immune responses mediate either protection or disease, depending on il-10 function.balb/c mice are highly susceptible and c57bl/6 relatively resistant to trypanosoma congolense infections. here we show that relatively resistant wild-type b6 mice infected with t. congolense survive significantly longer (> 200 days) than infected major histocompatibility complex (mhc) class ii-deficient b6 mice (approximately 50 days). we also show that blocking of the interleukin-10 (il-10) receptor induces early death of wild-type b6 mice infected with t. congolense (approximately 10 days), bu ...200717241399
toxicity and anti-trypanosomal effects of ethanolic extract of butyrospermum paradoxum (sapotaceae) stem bark in rats infected with trypanosoma brucei and trypanosoma congolense.the ethanolic extract of butyrospermum paradoxum stem bark, commonly used in the traditional treatment of various diseases including animal and human trypanosomosis in north-eastern nigeria, was tested for toxicity and anti-trypanosomal efficacy in rats infected with trypanosoma congolense and trypanosoma brucei. following intra-peritoneal administration, the extract induced behavioural changes, morbidity and mortality in the rats. the symptoms observed included anorexia, dehydration, depression ...200717321088
cytokine mrna profiles in bovine macrophages stimulated with trypanosoma congolense.it is known that different breeds of cattle display differential susceptibilities to trypanosome congolense infections, and that n'dama cattle remain more productive after infection than boran cattle which are more susceptible to t. congolense. macrophages from both breeds were cultured in vitro and the expressions of a number of cytokines and inos mrna were analyzed using real time rt-pcr after stimulation with antibody-opsonized trypanosomes. no significant difference was seen between the resp ...200717485933
the pathogenesis of anaemia in goats experimentally infected with trypanosoma congolense or trypanosoma brucei: use of the myeloid:erythroid ratio.the present study examined the development of anaemia in small east african goats experimentally infected with trypanosoma congolense or trypanosoma brucei. experimental goats received a primary trypanosome challenge on day 0, treated with diminazene aceturate on day 49 and received a secondary trypanosome challenge on day 77 of the 136-day experiment. both primary and secondary challenges were characterised by reduced peripheral erythrocyte counts, fall in packed cell volume (pcv), hypohaemoglo ...200716982150
preliminary application and evaluation of loop-mediated isothermal amplification (lamp) for detection of bovine theileriosis and trypanosomosis in tanzania.the sensitivity of lamp, pcr and microscopy to detect theileria spp. and trypanosoma congolense in field-derived bovine blood samples from tanzania was evaluated and compared. no parasites were detected by microscopy. furthermore, no bovine theileria spp. were detected by lamp and pcr from all the 24 samples collected from arusha. four and one out of 24 samples were positive for theileria congolense infection by lamp and pcr respectively while, 18 and nine out of 40 samples from dar es salaam we ...200718453242
trace minerals in serum of sheep infected with trypanosoma congolense.yankassa sheep (20) were grouped into a and b and infected with trypanosoma congolense isolated from a cow and maintained in mice. two milliliter x 10(7) parasites were used to infect group a. the course of the infection and serum trace minerals (iron, (fe) and copper, (cu) were studied and determined using atomic absorption spectrophotometer (aas). there was significant drop in concentration of iron (p<0.001) post infection (pi) while that of copper, no significant change (p>0.05). the values o ...200719070033
absence of correlation between karyotype profiles of trypanosoma congolense and resistance to isometamidium chloride.chromosome profiles of 10 trypanosoma (t.) congolense populations with different isometamidium sensitivities were compared using the pulsed field gel electrophoresis technique. the aim was to elucidate whether there was a karyotype pattern specific to eight isometamidium resistant phenotypes. analysis of the profiles indicated that all populations displayed several discrete bands at the region of small, intermediate and large chromosomes. the highest similarity was observed between two isolates ...200717537578
the comparative role of cattle, goats and pigs in the epidemiology of livestock trypanosomiasis on the plateau of eastern zambia.to determine and compare the prevalence of trypanosome infections in different livestock species (cattle, pigs and goats) in areas where game animals are scarce and livestock constitute the main food source of tsetse, a survey was conducted on the plateau of the eastern province of zambia in katete and petauke districts where glossina morsitans morsitans is the only tsetse species present. blood was collected from a total of 734 cattle, 333 goats and 324 pigs originating from 59 villages in both ...200717493757
heterogeneity in the trypanosomosis incidence in zebu cattle of different ages and sex on the plateau of eastern zambia.on the plateau of eastern zambia, trypanosomosis is endemic. glossina morsitans morsitans westwood (diptera: glossinidae), the only tsetse species present, is almost entirely dependent on livestock as its source of food with cattle being the most preferred host. to determine if tsetse challenge is distributed equally over the various age categories and sexes within a cattle herd, a longitudinal study of trypanosomosis incidence was conducted during the rainy season. a total of 354 head of cattle ...200717618594
tumor necrosis factor (tnf) receptor-1 (tnfp55) signal transduction and macrophage-derived soluble tnf are crucial for nitric oxide-mediated trypanosoma congolense parasite killing.control of trypanosoma congolense infections requires an early cell-mediated immune response. to unravel the role of tumor necrosis factor (tnf) in this process, 6 different t. congolense strains were used in 6 different gene-deficient mouse models that included tnf(-/-), tnf receptor-1 (tnfp55)(-/-), and tnf receptor-2 (tnfp75)(-/-) mice, 2 cell type-specific tnf(-/-) mice, as well as tnf-knock-in mice that expressed only membrane-bound tnf. our results indicate that soluble tnf produced by mac ...200717703428
african trypanosomiasis: naturally occurring regulatory t cells favor trypanotolerance by limiting pathology associated with sustained type 1 inflammation.tolerance to african trypanosomes requires the production of ifn-gamma in the early stage of infection that triggers the development of classically activated macrophages controlling parasite growth. however, once the first peak of parasitemia has been controlled, down-regulation of the type 1 immune response has been described. in this study, we have evaluated whether regulatory t cells (tregs) contribute to the limitation of the immune response occurring during trypanosoma congolense infection ...200717709488
first report of canine african trypanosomosis in the uk.a six-year-old neutered male jack russell terrier was presented two years after importation into the uk from southern africa with severe anaemia and abdominal distension. abdominal ultrasonography revealed the presence of hepato-splenomegaly and ascites. a diagnosis of trypanosomosis was made by blood smear examination. shortly after admission the dog collapsed and died. pcr analysis revealed a single infection with trypanosoma congolense savannah type. this is the first reported case of canine ...200717850267
sscp analysis of the p2 purine transporter tcoat1 gene of trypanosoma congolense leads to a simple pcr-rflp test allowing the rapid identification of diminazene resistant stocks.analyses were made on a trypanosoma congolense contig coding a putative p2-like nucleoside transporter (the contig was named in this study tcoat1). the sequence includes a start and stop codon and presents a high similarity with the gene tbat1 of t. brucei (smallest sum probability 2.8e-136). to investigate a possible link between point mutations and diminazene aceturate (da) resistance in mice, the tcoat1 putative genes of 26 t. congolense strains, characterised for da sensitivity in the single ...200617083909
the effect of starvation on the susceptibility of teneral and non-teneral tsetse flies to trypanosome infection.transmission of vector-borne diseases depends largely on the ability of the insect vector to become infected with the parasite. in tsetse flies, newly emerged or teneral flies are considered the most likely to develop a mature, infective trypanosome infection. this was confirmed during experimental infections where laboratory-reared glossina morsitans morsitans westwood (diptera: glossinidae) were infected with trypanosoma congolense or t. brucei brucei. the ability of mature adult tsetse flies ...200617199750
nonradioactive trans-sialidase screening assay.trans-sialidase (ts; e.c. 3.2.1.18) catalyzes the transfer of preferably alpha2,3-linked sialic acid to another glycan or glycoconjugate, forming a new alpha2,3-linkage to galactose or n-acetylgalactosamine. in the absence of an appropriate acceptor, ts acts as a sialidase, hydrolytically releasing glycosidically linked sialic acid. interest in ts has increased rapidly in recent years owing to its great relevance to the pathogenicity of trypanosomes and its possible application in the regiospeci ...200617072006
gene expression profiling in a mouse model for african trypanosomiasis.this study aimed to provide the foundation for an integrative approach to the identification of the mechanisms underlying the response to infection with trypanosoma congolense, and to identify pathways that have previously been overlooked. we undertook a large-scale gene expression analysis study comparing susceptible a/j and more tolerant c57bl/6 mice. in an initial time course experiment, we monitored the development of parasitaemia and anaemia in every individual. based on the kinetics of dis ...200617066074
response of trypanosoma vivax and trypanosoma congolense in zebu cattle in north cameroon to prophylactic treatment with two formulations of isometamidium.we tested the efficacy of two formulations of isometamidium in a tsetse-infested farm in north cameroon from 20 august 2000 to 5 january 2001. a total of 90 adult cattle were used in three groups of 30 each corresponding to two treated and one untreated control. drug efficacies were evaluated in terms of reduction of parasite incidence in the host's blood, maintenance of packed-cell volume (pcv) and weight gains. both drugs reduced the incidence of parasites even though re-infections 2 weeks aft ...200616777250
efficacy of dipalmitoylphosphatidylcholine liposome against african trypanosomes.we demonstrate here that dipalmitoylphosphatidylcholine (dppc) liposome has an antitrypanosomal effect, especially against the bloodstream forms (bsfs) of african trypanosomes (trypanosoma congolense, t. brucei rhodesiense, and t. brucei brucei). the dppc liposome significantly decreased the in vitro percentage of viable and motile bsf african trypanosomes but only marginally reduced the percentage of viable and motile procyclic form (pcf) of trypanosomes. the dppc liposome absorption was much m ...200616729700
effect of isometamidium chloride treatment on susceptibility of tsetse flies (diptera: glossinidae) to trypanosome infections.experiments were conducted to determine the effect of a single isometamidium chloride treatment of teneral tsetse flies, glossina morsitans morsitans westwood (diptera: glossinidae), on the subsequent susceptibility to an infection with trypanosoma congolense or trypanosoma brucei brucei. flies were offered a first bloodmeal on sterile gamma-irradiated defibrinated bovine blood that contained either 10 or 100 microg ofisometamidium chloride/ml. treated flies were subsequently infected with t. co ...200616739416
experimental african trypanosomiasis: lack of effective cd1d-restricted antigen presentation.balb/c mice are highly susceptible to african trypanosomiasis, whereas c57bl/6 mice are relatively resistant. other investigators have reported that the synthesis of igg antibodies to purified membrane form of variant surface glycoprotein (mfvsg) of trypanosoma brucei is cd1 restricted. in this study, we examine the role of the cd1d/nkt cell pathway in susceptibility and resistance of mice to infection by african trypanosomes. administration of anti-cd1d antibodies to trypanosoma congolense-infe ...200617096643
bovine transcriptome analysis by sage technology during an experimental trypanosoma congolense infection.in central and sub-saharan africa, trypanosomosis is a tsetse fly-transmitted disease, which is considered as the most important impediment to livestock production in the region. however, several indigenous west african taurine breeds (bos taurus) present remarkable tolerance to the infection. this genetic capability, named trypanotolerance, results from numerous biological mechanisms most probably under multigenic dependences, among which are control of the trypanosome infection by limitation o ...200617135528
cytokine mrna profiling of peripheral blood mononuclear cells from trypanotolerant and trypanosusceptible cattle infected with trypanosoma congolense.to examine differences in cytokine profiles that may confer tolerance/susceptibility to bovine african trypanosomiasis, n'dama (trypanotolerant, n = 8) and boran (trypanosusceptible, n = 8) cattle were experimentally challenged with trypanosoma congolense. blood samples were collected over a 34-day period, and rna was extracted from peripheral blood mononuclear cells. the expression levels of a panel of 14 cytokines were profiled over the time course of infection and between breeds. messenger rn ...200616985010
trypanosomosis in goats: current status.trypanosomosis is a major constraint on ruminant livestock production in africa, asia, and south america. the principal host species affected varies geographically, but buffalo, cattle, camels, and horses are particularly sensitive. natural infections with trypanosoma congolense, t. vivax, t. brucei, and t. evansi have been described in goats. trypanosomosis in goats produces acute, subacute, chronic, or subclinical forms, being t. vivax, t. congolense, and t. evansi, the most invasive trypanoso ...200617135529
beneficial effect of erythropoietin administration on murine infection with trypanosoma congolense.the effect of erythropoietin treatment on trypanosoma congolense infection in mice was studied. survival rates of mice were dramatically improved by treatment with recombinant human erythropoietin (r-hu-epo; 5,000 u/kg) when infected with 1,000 cells of t. congolense il3000 (p < 0.05). all the untreated mice infected with t. congolense il3000 died by day 9 of infection; however, 100%, 50%, and 25% of the mice treated with r-hu-epo for 8 days survived to day 20, day 40, and day 60 of the parasiti ...200616760514
equine trypanosomosis in the central river division of the gambia: a study of veterinary gate-clinic consultation records.the objective of this study was to provide epidemiological information of equine trypanosomosis in the central river division (crd) of the gambia. therefore, 2285 consultations records of equines, admitted in a gate-clinic at sololo in crd, were studied retrospectively. the data were recorded in the period between september 1995 and july 2002 and comprised consultations of 2113 horses and 172 donkeys. 'trypanosome infection' was the most frequently diagnosed condition and accounted for 61% of th ...200616814418
trypanosoma congolense procyclins: unmasking cryptic major surface glycoproteins in procyclic forms.in the tsetse fly, the protozoan parasite trypanosoma congolense is covered by a dense layer of glycosylphosphatidylinositol (gpi)-anchored molecules. these include a protease-resistant surface molecule (prs), which is expressed by procyclic forms early in infection, and a glutamic acid- and alanine-rich protein (garp), which appears at later stages. since neither of these surface antigens is expressed at intermediate stages, we investigated whether a gpi-anchored protein of 50 to 58 kda, previo ...200616896226
in vitro growth inhibition of bloodstream forms of trypanosoma brucei and trypanosoma congolense by iron chelators.african trypanosomes exert significant morbidity and mortality in man and livestock. only a few drugs are available for the treatment of trypanosome infections and therefore, the development of new anti-trypanosomal agents is required. previously it has been shown that bloodstream-form trypanosomes are sensitive to the iron chelator deferoxamine. in this study the effect of 13 iron chelators on the growth of trypanosoma brucei, t. congolense and human hl-60 cells was tested in vitro. with the ex ...200616914038
the application of pcr-elisa to the detection of trypanosoma congolense type savannah (tcs) in bovine blood samples.pcr-elisa was set up to detect strains of trypanosoma congolense type savannah (tcs) in field samples of buffy coats. results of pcr-elisa and pcr were compared and the effectiveness of both techniques was also compared with the murray's method for the detection of tcs in 257 bovine buffy coats. the pcr products were labelled with digoxigenin (dig-dutp) during amplification cycles of the repetitive satellite dna. a biotinylated dna capture probe was used to detect the pcr products by elisa in st ...200617041561
a comparative longitudinal study of bovine trypanosomiasis in tsetse-free and tsetse-infested zones of the amhara region, northwest ethiopia.a study was conducted to determine the incidence of trypanosome infections in cattle in tsetse-free and tsetse-infested zones of the amhara region of northwest ethiopia. a total of six sentinel herds were established and the cattle observed during a period of 8 consecutive months. the prevalence of seropositive cattle was high in both the tsetse-free and tsetse-infested zones. the average monthly incidence of trypanosome infection, determined using molecular diagnostic tools, was 20.9% and 25.7% ...200616675127
bovine trypanotolerance: a natural ability to prevent severe anaemia and haemophagocytic syndrome?trypanotolerance is the capacity of certain west-african, taurine breeds of cattle to remain productive and gain weight after trypanosome infection. laboratory studies, comparing trypanosoma congolense infections in trypanotolerant n'dama cattle (bos taurus) and in more susceptible boran cattle (bos indicus), confirmed the field observations. experiments using haemopoietic chimeric twins, composed of a tolerant and a susceptible co-twin, and t cell depletion studies suggested that trypanotoleran ...200616678182
the transmissibility of trypanosoma congolense seems to be associated with its level of resistance to isometamidium chloride.in large parts of africa the control of livestock trypanosomiasis relies on the use of trypanocidal drugs. resistance against the available compounds is developing rapidly in the trypanosome population. the effect of the development of drug resistance on the fitness of the trypanosome is not well known. to determine the effect of the development of resistance to isometamidium chloride on the trypanosome's transmissibility, transmission experiments were conducted. use was made of three isogenic c ...200616303254
comparison of the virulence of trypanosoma congolense strains isolated from cattle in a trypanosomiasis endemic area of eastern zambia.the virulence of 31 genetically different trypanosoma congolense strains belonging to the savannah subgroup and isolated from cattle at 11 sites in a trypanosomiasis endemic area of eastern zambia was compared. virulence testing, done in of1 mice, revealed three virulence categories. strains were considered extremely virulent when the median survival time ranged between 5 and 9 days. moderately virulent strains had a median survival time between 10 and 30 days and low virulence, more than 30 day ...200616516215
a modified aflp for trypanosoma congolense isolate characterisation.the amplified fragment length polymorphism (aflp) technique is a reliable and powerful dna fingerprint tool for genetic characterisation and analysis. in this paper, we described a modified aflp with high resolution for trypanosoma congolense using one enzyme and agarose or elchrom gel electrophoresis. eleven allopatric and fourteen sympatric isolates of t. congolense savannah were used to assess the resolution of the method and its ability to characterise t. congolense isolates. two enzymes (ec ...200616516323
comparison of the transmissibility of trypanosoma congolense strains, isolated in a trypanosomiasis endemic area of eastern zambia, by glossina morsitans morsitans.transmission experiments were conducted to compare the transmissibility of genetically different trypanosoma congolense (savannah subgroup) strains isolated from cattle in a trypanosomiasis endemic area of eastern zambia. a total of 17 strains were compared. three strains were extremely virulent with a short pre-patent period, high parasitaemia and a short median survival time (between 5 and 9 days) in mice. the remainder of the strains belonged to the moderate (6 strains) or low (8 strains) vir ...200616719960
isometamidium sensitivity of trypanosoma congolense stocks from cattle in west africa tested in mice and the drug incubation infectivity test.four trypanosoma (t.) congolense reference clones with known isometamidium sensitivity and 16 t. congolense stocks from cattle in kénédougou in south-western burkina faso, an area with known history of drug resistance, were characterised with the standard mouse test (smt) and the drug incubation infectivity test (diit). all field stocks from kénédougou were resistant to 1.0 mg/kg bw isometamidium in the smt. fourteen stocks (87.5%) also proved to be refractory to 10 mg/kg bw. testing with the di ...200616256933
experimental african trypanosomiasis: a subset of pathogenic, ifn-gamma-producing, mhc class ii-restricted cd4+ t cells mediates early mortality in highly susceptible mice.infections of highly susceptible balb/c mice with virulent strains of trypanosoma congolense or trypanosoma brucei result in rapid death (8 days). we have previously shown that this mortality is ifn-gamma dependent. in this study we show that ifn-gamma is produced predominantly by cd3+thy1.2+tcrbeta+cd4+ t cells shortly before the death of infected mice. mortality may therefore be dependent on ifn-gamma-producing cd4+ t cells. surprisingly, infected cd4+/+ and cd4-/- balb/c mice have similar par ...200616424202
trypanosomosis prevalence in cattle on mafia island (tanzania).during two consecutive surveys (february and august/sept 2002), a total of 970 cattle from the cattle population of mafia island (united republic of tanzania) were blood-sampled. all blood samples were microscopically screened for the presence of trypanosomes and a portion of these were checked for antibodies with an ab-elisa and for the presence of trypanosomal dna with pcr. microscopic evidence of trypanosomes of the congolense group (sub-genus nannomonas) was found in 0.8% of the animals (8/9 ...200616574325
cr3 (cd11b/cd18) is the major macrophage receptor for igm antibody-mediated phagocytosis of african trypanosomes: diverse effect on subsequent synthesis of tumor necrosis factor alpha and nitric oxide.immunoglobulin m (igm) antibodies to the variant surface glycoproteins (vsg) of african trypanosomes are the first and predominant class of anti-trypanosomal antibodies in the infected host. they are a major factor in controlling waves of parasitemia, but not in long-term survival. the macrophage receptor(s) that enables phagocytosis of igm anti-vsg-coated african trypanosomes is unknown. we assessed whether complement receptor cr3 (cd11b/cd18) might be involved in mediating phagocytosis of tryp ...200616616573
interferon-gamma and nitric oxide in combination with antibodies are key protective host immune factors during trypanosoma congolense tc13 infections.the control of chronic trypanosoma congolense trypanosomiasis was analyzed using several gene-deficient mouse strains. first, interferon (ifn)-gamma receptor (ifn-gamma-r)-deficient mice were used to show that ifn- gamma -mediated immune activation is crucial for parasitemia control. second, infections in major histocompatibility complex (mhc) class ii-deficient mice indicate that this molecule is needed for initiation of ifn- gamma and subsequent tumor necrosis factor (tnf) production. downstre ...200616652287
trypanosoma congolense: paraoxonase 1 prolongs survival of infected mice.in vitro studies have suggested that a fraction of human high density lipoprotein (hdl), termed trypanosome lysis factor (tlf), can protect against trypanosome infection. we examined the involvement of two proteins located in the tlf fraction, apolipoprotein a-ii (apoa-ii) and paraoxonase 1 (pon1), against trypanosome infection. to test whether pon1 is involved in trypanosome resistance, we infected human pon1 transgenic mice, pon1 knockout mice, and wild-type mice with trypanosoma congolense. w ...200616682028
an update of the bovine trypanosomosis situation at the edge of hluhiuwe-imfolozi park, kwazulu-natal province, south africa.to obtain updated data on and assess the contribution of trypanosomosis to the disease burden of cattle kept at the edge of the hluhluwe-imfolozi park, a survey was conducted at mvutshini dip. use was made of a purposeful sampling strategy by restricting sampling to animals that the livestock owner considered to be in poor condition. of a total of 76 blood samples collected, 26 were parasitologically positive and 46 were positive on pcr/rflp. almost all infections were due to trypanosoma congole ...200616715881
development of an adaptive tsetse population management scheme for the luke community, ethiopia.since 1996, tsetse (glossina spp.) control operations, using odor-baited traps, have been carried out in the luke area of gurage zone, southwestern ethiopia. glossina morsitans submorsitans newstead was identified as the dominant species in the area, but the presence of glossina fuscipes newstead and glossina pallidipes austen also was recorded. here, we refer to the combined number of these three species and report the work undertaken from october 2002 to october 2004 to render the control syst ...200516465742
ability of trypanosome-infected tsetse flies (diptera: glossinidae) to acquire an infection with a second trypanosome species.the epidemiology of human and animal trypanosomiasis is determined to a large extent by the number of infected tsetse flies in a specific area. in the field, a substantial proportion of infected flies carry mixed trypanosome infections. the way in which these tsetse flies acquire a mixed infection is not fully understood. in particular, the susceptibility of tsetse flies to sequential infection with trypanosomes is not well understood. accordingly, laboratory studies were made of the effects of ...200516465745
impaired kupffer cells in highly susceptible mice infected with trypanosoma congolense.in highly susceptible balb/c mice infected with trypanosoma congolense, the total number of kupffer cells in the liver remains constant; however, their mean size increases fivefold towards the terminal stage. about 25% of kupffer cells undergo apoptosis. we suggest that development of an impairment of the macrophage system might be a major mechanism for inefficient elimination of trypanosomes.200516299337
efficiency and limits of the serial analysis of gene expression (sage) method: discussions based on first results in bovine trypanotolerance.post genomic biotechnologies, such as transcriptome analysis, are now efficient enough to characterize the full complement of genes involved in the expression of specific biological functions. one of them is the serial analysis of gene expression (sage) technique. sage involves the construction of transcript libraries for a quantitative analysis of the entire set of genes expressed or inactivated at particular stages of cellular activation. bioinformatic comparisons in hosts and pathogens genomi ...200516144719
tnf-alpha mediates the development of anaemia in a murine trypanosoma brucei rhodesiense infection, but not the anaemia associated with a murine trypanosoma congolense infection.development of anaemia in inflammatory diseases is cytokine-mediated. specifically, the levels of tumour necrosis factor-alpha (tnf-alpha), produced by activated macrophages, are correlated with severity of disease and anaemia in infections and chronic disease. in african trypanosomiasis, anaemia develops very early in infection around the time when parasites become detectable in the blood. since the anaemia persists after the first waves of parasitaemia when low numbers of trypanosomes are circ ...200515730385
the detection of non-rotat 1.2 trypanosoma evansi.the majority of trypanosoma evansi can be detected using diagnostic tests based on the variant surface glycoprotein (vsg) of trypanosoma evansi rode trypanozoon antigen type (rotat) 1.2. exceptions are a number of t. evansi isolated in kenya. to characterize t. evansi that are undetected by rotat 1.2, we cloned and sequenced the vsg cdna from t. evansi jn 2118hu, an isolate devoid of the rotat 1.2 vsg gene. a 273 bp dna segment of the vsg gene was targeted in pcr amplification for the detection ...200515804376
sodalis glossinidius (enterobacteriaceae) and vectorial competence of glossina palpalis gambiensis and glossina morsitans morsitans for trypanosoma congolense savannah type.sodalis glossinidius is an endosymbiont of glossina palpalis gambiensis and glossina morsitans morsitans, the vectors of trypanosoma congolense. the presence of the symbiont was investigated by pcr in trypanosoma congolense savannah type-infected and noninfected midguts of both fly species, and into the probosces of flies displaying either mature or immature infection, to investigate possible correlation with the vectorial competence of tsetse flies. sodalis glossinidius was detected in all midg ...200515942697
understanding bovine trypanosomiasis and trypanotolerance: the promise of functional genomics.african bovine trypanosomiasis, caused by the protozoan parasite trypanosoma congolense, is endemic throughout sub-saharan africa and is a major constraint on livestock production. a promising approach to disease control is to understand and exploit naturally evolved trypanotolerance. we describe the first attempt to investigate the transcriptional response of susceptible boran (bos indicus) cattle to trypanosome infection via a functional genomics approach using a bovine total leukocyte (botl) ...200515808304
expression of a gene encoding trypanosoma congolense putative abc1 family protein is developmentally regulated.during the attempt to seek t. congolense species-specific diagnostic antigens, we discovered one cdna clone (p74) encoding 74 kda putative abc1 protein (p74) from t. congolense pcf cdna library. it has been suggested that members of the abc1 family are novel chaperonins and essential for both the mitochondrial electron transfer in the bc 1 complex and the coenzyme q biosynthesis. although abc1 protein in yeast has a nuclear or mitochondrial subcellular location, neither nuclear localization sign ...200515750311
the susceptibility of trypanosoma congolense isolated in zambézia province, mozambique, to isometamidium chloride, diminazene aceturate and homidium chloride.resistance to trypanocidal drugs has been detected in various african countries and is a serious impediment to the control of livestock trypanosomosis. to determine whether drug resistant trypanosome strains are present in the zambézia province of mozambique a study was initiated. to assess the effect of the farming system and the drug-use regimen on the development of drug resistance, trypanosome isolates were collected from cattle from subsistence and commercial livestock production systems. t ...200516562737
transmissibility of trypanosoma brucei during its development in cattle.recent outbreaks of trypanosoma brucei rhodesiense sleeping sickness in soroti district of eastern uganda have demonstrated the important role cattle can play as reservoirs of this parasite. to clarify the epidemiological importance of the cattle reservoir, experiments were conducted to determine the ease with which t. brucei is transmitted during the course of its development in friesian cattle. the development of t. brucei in cattle is characterized by an acute phase with high levels of parasi ...200516135189
marker-assisted introgression of trypanotolerance qtl in mice.a marker-assisted introgression (mai) experiment was conducted to use genetic markers to transfer each of the three trypanotolerance qtl from a donor mouse strain, c57bl/6, into a recipient mouse strain, a/j. we used a backcross strategy that consisted of selecting two lines, each carrying two of the donor qtl alleles through the backcross (bc) phase. at the fourth bc generation, single-carrier animals were selected for the production of homozygous animal in the intercross phase. the qtl regions ...200515859356
susceptibility of west african dwarf goats and wad x saanen crosses to experimental infection with trypanosoma congolense.west african dwarf goats (wads) and their saanen crosses were experimentally infected with trypanosoma congolense. no significant differences were found between trypanosome parasitaemia and antibody response of the crossbred and wad goats. neither the wad goats nor the saanen crosses were able to control the drop in pcv following trypanosome infection. the level of anaemia caused by the trypanosome infection was similar in the two breeds during the trial. based on these findings, no difference i ...200515893063
alternative oxidase (aox) genes of african trypanosomes: phylogeny and evolution of aox and plastid terminal oxidase families.to clarify evolution and phylogenetic relationships of trypanosome alternative oxidase (aox) molecules, aox genes (cdnas) of the african trypanosomes, trypanosoma congolense and trypanosoma evansi, were cloned by pcr. both aoxs possess conserved consensus motifs (-e-, -exxh-). the putative amino acid sequence of the aox of t. evansi was exactly the same as that of t. brucei. a protein phylogeny of trypanosome aoxs revealed that three genetically and pathogenically distinct strains of t. congolen ...200516014016
inhibition of a cathepsin l-like cysteine protease by a chimeric propeptide-derived inhibitor.like other papain-related cathepsins, congopain from trypanosoma congolense is synthesized as a zymogen. we have previously identified a proregion-derived peptide (pcp27), acting as a weak and reversible inhibitor of congopain. pcp27 contains a 5-mer yhnga motif, which is essential for selectivity in the inhibition of its mature form [lalmanach, g., lecaille, f., chagas, j. r., authié, e., scharfstein, j., juliano, m. a., and gauthier, f. (1998) j. biol. chem. 273, 25112-25116]. in the work pres ...200516060657
influence of an experimental trypanosoma congolense infection and plane of nutrition on milk production and some biochemical parameters in west african dwarf goats.the interactions of trypanosomosis and plane of nutrition on health and productivity of multiparous and primiparous west african dwarf (wad) does were studied in a multi-factorial experiment including diet (supplementation or basal diet) and infection (infected or control). experimental does were infected with trypanosoma congolense at the beginning of the second week post-kidding and monitored for 16 weeks after infection. trypanosome infection significantly reduced packed cell volume (pcv) (co ...200515715994
susceptibility of tnf-alpha-deficient mice to trypanosoma congolense is not due to a defective antibody response.c57bl/6 mice deficient in one or two copies of the gene for tumor necrosis factor alpha (tnf-alpha) were more susceptible to trypanosoma congolense infection than their resistant, wild-type counterparts. the number of tnf-alpha genes was correlated with the capacity to control parasitaemia and with survival time. absence of tnf-alpha resulted in a diminished capacity to form germinal centres in lymph nodes and spleen. since germinal centres are involved in antibody production and affinity matura ...200415533287
protective efficacy of isometamidium chloride and diminazene aceturate against natural trypanosoma brucei, trypanosoma congolense and trypanosoma vivax infections in cattle under a suppressed tsetse population in uganda.the protective efficacy of isometamidium chloride (ismm) and diminazene aceturate (dim) against trypanosoma brucei, trypanosoma congolense and trypanosoma vivax infections in cattle under a suppressed tsetse population was assessed in southeast uganda. a total of 66 and 57 trypanosome-infected cattle were treated with ismm and dim, respectively together with 177 trypanosome-free animals not treated were followed for 12 months, checked every 4 weeks. there was no statistical difference in the mea ...200415580773
use of the serial analysis of gene expression (sage) method in veterinary research: a concrete application in the study of the bovine trypanotolerance genetic control.new postgenomic biotechnologies, such as transcriptome analyses, are now able to characterize the full complement of genes involved in the expression of specific biological functions. one of these is the serial analysis of gene expression (sage) technique, which consists of the construction of transcripts libraries for a quantitative analysis of the entire gene(s) expressed or inactivated at a particular step of cellular activation. bioinformatic comparisons in the bovine genomic databases allow ...200415604489
epidemiological factors that influence time-to-treatment of trypanosomosis in orma boran cattle raised at galana ranch, kenya.four thousand nine hundred and seventy-one trypanosomosis-surveillance records from an open population of orma boran cattle raised under natural trypanosomosis challenge in galana ranch, kenya between the years 1990 and 2000 were analysed. the objective of the analysis was to identify epidemiological factors that influenced time-to-treatment of trypanosomosis cases. under the surveillance programme, blood was being examined fortnightly for trypanosomosis using buffy coat technique. infected anim ...200415019142
the secretion of acute phase proteins and inflammatory cytokines during trypanosoma congolense infection is not affected by the absence of the tnf-alpha gene.tumor necrosis factor-alpha (tnf-alpha) plays a role in the host's defence against infections with african trypanosomes. it helps to control the blood stream form of the parasite and in trypanosoma congolense infections, it also prolongs survival. the mechanisms by which this cytokine can influence parasitemia and survival are unknown. therefore, the levels of acute phase proteins and other inflammatory cytokines were monitored in trypano-tolerant wild-type and tnf-alpha-deficient mice during a ...200415301973
Refresh
firstprev
12345678910...
nextlast
Displaying items 201 - 300 of 1259