Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| 1-octen-3-ol isolated from bont ticks attracts amblyomma variegatum. | volatiles from various life-stages of the bont ticks amblyomma variegatum and a. hebraeum were collected by using solid-phase microfibers and charcoal traps. an octenol isomer was found to be a major constituent of most of the tick material sampled and was identified as 1-octen-3-ol by gas chromatography-mass spectrometry and by using antenna of the tsetse fly glossina brevipalpis in gas chromatography-linked antennogram detection. release of this compound increased during molt to adulthood and ... | 2001 | 11441439 |
| a contribution towards simplifying area-wide tsetse surveys using medium resolution meteorological satellite data. | a raster or grid-based geographic information system with data on tsetse, trypanosomiasis, animal production, agriculture and land use has recently been developed in togo. the area-wide sampling of tsetse fly, aided by satellite imagery, is the subject of two separate papers. this paper follows on a first paper, published in this journal, describing the generation of digital tsetse distribution and abundance maps and how these accord with the local climatic and agro-ecological setting. such maps ... | 2001 | 11583596 |
| principles of area-wide integrated tsetse fly control using the sterile insect technique. | the tsetse fly and the disease trypanosomosis it transmits, is one of the most severe medical and veterinary problems in africa, infecting around 50,000 people every year and preventing the development of sustainable and productive agricultural systems. the most efficient way to contain the disease is by the management of entire populations of the vector (area-wide approach) using a combination of several control methods in an integrated pest management campaign. a very powerful method for integ ... | 2001 | 11803833 |
| a density-dependent model with reinvasion for estimating tsetse fly populations (diptera: glossinidae) through trapping. | a simple density-dependent reinvasion model is described and used to estimate tsetse fly populations on the basis of removal trapping experiments. the model was tested on glossina fuscipes fuscipes newstead in the central african republic and g. palpalis palpalis (robineau-desvoidy) in the republic of congo (brazzaville). the density-dependence is modelled by postulating that the inflow of flies each day is proportional to the deficit relative to the equilibrium population. non-linear least squa ... | 2001 | 11415471 |
| the origins of a new trypanosoma brucei rhodesiense sleeping sickness outbreak in eastern uganda. | sleeping sickness, caused by two trypanosome subspecies, trypanosoma brucei gambiense and trypanosoma brucei rhodesiense, is a parasitic disease transmitted by the tsetse fly in sub-saharan africa. we report on a recent outbreak of t b rhodesiense sleeping sickness outside the established south-east ugandan focus, in soroti district where the disease had previously been absent. soroti district has been the subject of large-scale livestock restocking activities and, because domestic cattle are im ... | 2001 | 11530149 |
| [the epidemiology of human african trypanosomiasis: a complex multifactorial history]. | sleeping sickness has long been known from descriptions by arab merchants and slave traders. however it was not until 1901 that forbes discovered the offending agent and 1903 that bruce described the role of the tsetse fly. the basic epidemiological transmission cycle was described less than 10 years later. although the main outline of the original model can still be considered as sound, subsequent research has greatly expanded our knowledge. molecular biology has identified different parasites ... | 2001 | 11803821 |
| the surface coat of procyclic trypanosoma brucei: programmed expression and proteolytic cleavage of procyclin in the tsetse fly. | trypanosoma brucei, the protozoan parasite causing sleeping sickness, is transmitted by a tsetse fly vector. when the tsetse takes a blood meal from an infected human, it ingests bloodstream form trypanosomes that quickly differentiate into procyclic forms within the fly's midgut. during this process, the parasite loses the 10(7) molecules of variant surface glycoprotein that formed its surface coat, and it develops a new coat composed of several million procyclin molecules. procyclins, the prod ... | 2001 | 11171982 |
| estimation of trypanosomal status by the buffy coat technique and an antibody elisa for assessment of the impact of trypanosomosis on health and productivity of n'dama cattle in the gambia. | the buffy coat/dark ground phase contrast technique (bct) and an indirect antibody enzyme immunoassay (elisa) were employed to assess the trypanosomal status of 32 n'dama cattle, aged 19-28 months, exposed to natural challenge of glossina morsitans submorsitans and g. palpalis gambiensis. prior to the start of the investigation animals experienced 9-16 months of tsetse challenge in the study area. blood and corresponding serum samples were examined monthly for a period of 8 months for patent par ... | 2001 | 11163695 |
| mark-recapture and moran curve estimates of the survival probabilities of an island population of tsetse flies glossina morsitans morsitans (diptera: glossinidae). | a study on populations of glossina morsitans morsitans westwood on antelope island, lake kariba, zimbabwe provided jolly-seber (j-s) mark-recapture estimates of adult survival and moran curve estimates of the overall survival of all developmental stages. for females, moran survival estimates derived using ox fly-round catches showed similar trends to, but were more variable than, those calculated from j-s population estimates. regression of one set on the other removed only 26% of the variance. ... | 2001 | 11228585 |
| characterization of genes expressed in the salivary glands of the tsetse fly, glossina morsitans morsitans. | salivary gland products of haematophogous insects including tsetse flies (diptera: glossinidia) are involved in antihaemostasis to allow for efficient blood feeding. in addition, salivary products of tsetse are thought to indirectly support the metacyclogenesis and eventual transmission of the african trypanosome protozoan parasites to their mammalian hosts. we have previously characterized the major anticoagulant, tsetse thrombin inhibitor (tti), from salivary extracts, and described molecular ... | 2001 | 11240638 |
| the effect of temperature and saturation deficit on mortality in populations of male glossina m. morsitans (diptera: glossinidae) in zimbabwe and tanzania. | the methods of bailey and of jolly and seber were used to provide maximum likelihood estimates of population parameters for jackson's classical mark-recapture experiments on males of the tsetse fly glossina m. morsitans westwood. these were compared with jolly-seber (j-s) estimates for the same fly from more recent work on antelope island, lake kariba, zimbabwe. the bailey estimates of birth and death rates and total population size had markedly lower variances than jackson's originals. both set ... | 2001 | 11260721 |
| use of deltamethrin 'pour-on' insecticide for the control of cattle trypanosomosis in the presence of high tsetse invasion. | a deltamethrin 'pour-on' insecticide was applied monthly to over 2000 cattle exposed to a high challenge of drug-resistant trypanosomes and high tsetse re-invasion pressure in the ghibe valley, south-west ethiopia. blood samples were taken monthly from an average of 760 cattle for determination of pcv and presence of trypanosomes. the area of the valley is approximately 350 km2 and the cattle grazed in roughly four locations covering about a quarter to half of the area. two years before the tria ... | 2001 | 11297107 |
| the changing distribution of two riverine tsetse flies over 15 years in an increasingly cultivated area of burkina faso. | changes in the distribution of two riverine tsetse flies, glossina tachinoides westwood and glossina palpalis gambiensis vanderplank are described in an agro-pastoral area of burkina faso subject to increasing human population pressure and land use change. two similar entomological surveys (one trap every 100 m, 120 km of river) were conducted in 1981 and 1996. changes in tsetse distribution were compared to land use changes through high resolution remote sensing imagery (landsat, spot). there w ... | 2001 | 11415469 |
| a novel application of gene arrays: escherichia coli array provides insight into the biology of the obligate endosymbiont of tsetse flies. | symbiotic associations with microorganisms are pivotal in many insects. yet, the functional roles of obligate symbionts have been difficult to study because it has not been possible to cultivate these organisms in vitro. the medically important tsetse fly (diptera: glossinidae) relies on its obligate endosymbiont, wigglesworthia glossinidia, a member of the enterobacteriaceae, closely related to escherichia coli, for fertility and possibly nutrition. we show here that the intracellular wiggleswo ... | 2001 | 11404467 |
| a trypanosome structure involved in transmitting cytoplasmic information during cell division. | african trypanosomes are protozoan parasites that cause sleeping sickness in humans through a tsetse fly vector. the procyclic form of trypanosoma brucei has a single, attached flagellum that describes a helical path along the cell from posterior to anterior. during division, a specific flagellum-flagellum connection is elaborated between the new and old flagellum. this connector was present only during cell duplication and was found to be involved in the replication of the helical cell pattern ... | 2001 | 11641501 |
| degradation of the unstable ep1 mrna in trypanosoma brucei involves initial destruction of the 3'-untranslated region. | kinetoplastid protozoa regulate their gene expression primarily through control of mrna degradation and translation. we describe here the degradation of three reporter mrnas in trypanosoma brucei. one mrna had the 3'-untranslated region (3'-utr) from the developmentally regulated ep1 mrna, which is abundant in the procyclic (tsetse fly) form of the parasite but is almost undetectable in the bloodstream form. this untranslated region includes a 26 nt u-rich sequence that causes extreme rna instab ... | 2001 | 11713321 |
| characterization of the adenosine deaminase-related growth factor (adgf) gene family in drosophila. | a novel family of growth factors, with sequence similarity to adenosine deaminase, has been identified in various organisms including flesh fly, tsetse fly, sand fly, mollusk and human. the human homologue, cecr1, is a candidate gene for the genetic disorder cat eye syndrome. here, we describe six members of this growth factor family in drosophila and two in vertebrates. the six drosophila genes, named adenosine deaminase-related growth factors (adgf), are found at three different chromosomal lo ... | 2001 | 11738815 |
| the endosymbionts of tsetse flies: manipulating host-parasite interactions. | through understanding the mechanisms by which tsetse endosymbionts potentiate trypanosome susceptibility in tsetse, it may be possible to engineer modified endosymbionts which, when introduced into tsetse, render these insects incapable of transmitting parasites. in this study we have assayed the effect of three different antibiotics on the endosymbiotic microflora of tsetse (glossina morsitans morsitans). we showed that the broad-spectrum antibiotics, ampicillin and tetracycline, have a dramati ... | 2001 | 11334953 |
| genome size determination and coding capacity of sodalis glossinidius, an enteric symbiont of tsetse flies, as revealed by hybridization to escherichia coli gene arrays. | recent molecular characterization of various microbial genomes has revealed differences in genome size and coding capacity between obligate symbionts and intracellular pathogens versus free-living organisms. multiple symbiotic microorganisms have evolved with tsetse fly, the vector of african trypanosomes, over long evolutionary times. although these symbionts are indispensable for tsetse fecundity, the biochemical and molecular basis of their functional significance is unknown. here, we report ... | 2001 | 11443086 |
| unravelling the phylogenetic relationships of african trypanosomes of suids. | african trypanosomes of the subgenera nannomonas and pycnomonas have been recorded from both wild and domestic suids. however, complete descriptions of some of these trypanosomes with regard to host range, pathogenicity, transmission and distribution are still lacking. neither the recently described trypanosoma (nannomonas) godfreyi nor trypanosoma (nannomonas) congolense tsavo have been isolated from mammalian hosts, while trypanosoma (pycnomonas) suis remains the rarest of the salivarian trypa ... | 2001 | 11444615 |
| deletion of a novel protein kinase with px and fyve-related domains increases the rate of differentiation of trypanosoma brucei. | growth control of african trypanosomes in the mammalian host is coupled to differentiation of a non-dividing life cycle stage, the stumpy bloodstream form. we show that a protein kinase with novel domain architecture is important for growth regulation. zinc finger kinase (zfk) has a kinase domain related to rac and s6 kinases flanked by a fyve-related zinc finger and a phox (px) homology domain. to investigate the function of the kinase during cyclical development, a stable transformation proced ... | 2001 | 11454198 |
| antigenic variation in trypanosomes: enhanced phenotypic variation in a eukaryotic parasite. | african trypanosomes are unicellular, eukaryotic parasites that live extracellularly in a wide range of mammals, including humans. they have a surface coat, composed of variant surface glycoprotein (vsg), which probably is essential and acts as a defence against general innate immunity and against acquired immunity directed at invariant surface antigens. in effect, the vsg is the only antigen that the host can target, and each trypanosome expresses only one vsg. to counter specific antibodies ag ... | 2001 | 11461029 |
| effect of gamma-irradiation on serum samples on the diagnostic performance of elisa methods for the detection of trypanosomal antibodies. | the study investigated the effect of gamma-irradiation on bovine serum samples on the ability of enzyme-linked immunosorbent assay (elisa) methods to detect trypanosomal antibodies. the serum samples were analysed using two standardised indirect elisa systems. higher measurement values were observed for most gamma-irradiated antibody positive and negative test samples. using cut-off points, determined from the analysis of a non-irradiated trypanosomal antibody-negative population, the gamma-irra ... | 2001 | 11470177 |
| genetic differentiation of glossina morsitans centralis populations. | variation at mitochondrial and microsatellite loci was used to study the breeding and dispersal structure of glossina morsitans centralis, in six natural populations from botswana, the caprivi strip (namibia), zambia, and in a laboratory culture derived from singida, tanzania. only seven mitochondrial haplotypes were found. mean diversity averaged over the six natural populations was 0.216 +/- 0.085. the fixation index fst = 0.866 indicated a high degree of genetic differentiation among populati ... | 2001 | 11520361 |
| multiple procyclin isoforms are expressed differentially during the development of insect forms of trypanosoma brucei. | transmission of trypanosoma brucei by the tsetse fly entails several rounds of differentiation as the parasite migrates through the digestive tract to the salivary glands of its vector. differentiation of the bloodstream to the procyclic form in the fly midgut is accompanied by the synthesis of a new coat consisting of ep and gpeet procyclins. there are three closely related ep isoforms, two of which (ep1 and ep3) contain n-glycans. to identify the individual ep isoforms that are expressed early ... | 2001 | 11575917 |
| parturition hormone in the tsetse glossina morsitans: activity in reproductive tissues from other species and response of tsetse to identified neuropeptides and other neuroactive compounds. | parturition hormone (ph) activity is present not only in the uterus of the tsetse glossina morsitans but also in the oviducts of bombyx mori and schistocerca gregaria, as well as the ejaculatory duct of s. gregaria males. activity thus appears to be present in the reproductive ducts of diverse insect taxa. to determine whether any of the common insect neuropeptides are capable of mimicking the effect of ph, 35 identified neuropeptides and analogs were evaluated for ph activity. modest ph activit ... | 2000 | 12770225 |
| systematic relationships and cospeciation of bacterial endosymbionts and their carpenter ant host species: proposal of the new taxon candidatus blochmannia gen. nov. | the systematic relationships of intracellular bacteria of 13 camponotus species (carpenter ants) from america and europe were compared to those of their hosts. phylogenetic trees of the bacteria and the ants were based on 16s rdna (rrs) gene sequences and mitochondrial cytochrome oxidase subunit i (coi) gene sequences, respectively. the bacterial endosymbionts of camponotus spp. form a distinct lineage in the y-subclass of the proteobacteria. the taxa most closely related to these bacteria are e ... | 2000 | 11034499 |
| behaviour of glossina morsitans morsitans westwood (diptera: glossinidae) on waterbuck kobus defassa ruppel and feeding membranes smeared with waterbuck sebum indicates the presence of allomones. | the behavioural responses of caged individual teneral glossina morsitans morsitans on waterbuck and ox and on feeding membranes with and without smears of different doses of waterbuck sebum were compared. no significant difference was found in the initial landing behaviour on the two animals, nor on treated and control parts of the membrane. however, the subsequent behaviours of the flies were significantly different. whereas none of the flies that landed on the ox showed any escape behaviour, m ... | 2000 | 11114392 |
| hybridization asymmetries in tsetse (diptera: glossinidae): role of maternally inherited factors and the tsetse genome. | among the morsitans-group of tsetse there are several pairs of taxa in which there is a marked hybridization asymmetry (ha), i.e., one cross produces significantly more offspring than does the reciprocal cross. to investigate the relative contribution of maternally inherited factors (mif) and chromosomal factors to ha, three hybrid lines were established in which flies have mif from one taxon and chromosome from another. ha was then compared among crosses of the parental taxa and crosses of each ... | 2000 | 11126547 |
| transport of methionine in trypanosoma brucei brucei. | african trypanosomes live free in the bloodstream and central nervous system of mammalian hosts and also within the midgut of the tsetse fly vectors which transmit them. the parasite plasma membrane represents the interface between both hosts and parasite, and trypanosomes accumulate many essential metabolites via specific transport processes. l-methionine uptake by procyclic and bloodstream forms of trypanosoma brucei has been measured and shown to be mediated by a transporter presenting simila ... | 2000 | 11163438 |
| the major cell surface glycoprotein procyclin is a receptor for induction of a novel form of cell death in african trypanosomes in vitro. | bloodstream forms (bsf) and procyclic culture forms (pcf) of african trypanosomes were incubated with a variety of lectins in vitro. cessation of cell division and profound morphological changes were seen in procyclic forms but not in bsf after incubation with concanavalin a (con a), wheat germ agglutinin and ricinus communis agglutinin. these lectins caused the trypanosomes to cease division, become round and increase dramatically in size, the latter being partially attributable to the formatio ... | 2000 | 11163441 |
| a newly developed odour-baited "h trap" for the live collection of glossina brevipalpis and glossina austeni (diptera: glossinidae) in south africa. | a new trap, named the "h trap", was developed at hellsgate tsetse research station in south africa for the simultaneous collection of live glossina brevipalpis newstead and glossina austeni newstead. its design followed an evaluation of the responses of the two species towards traps that are used elsewhere in africa for the collection of other tsetse fly species. these traps were found at hellsgate to be unsuitable for capturing both g. brevipalpis and g. austeni. some new trap designs and many ... | 2000 | 10843318 |
| [vectorial competence of non-teneral glossina morsitans morsitans (mall strain) flies infected by trypanosoma (nannomonas) congolense il 1180]. | non-teneral tsetse flies of glossina morsitans morsitans (strain mall) about 16 days old were fed, once, on a rat infected by trypanosoma congolense il 1180. the global vectorial competence (vc) of these flies was appraised at 0.1035. vc in males was more important than for females. infection by mesoprocyclic index was greater in female flies than in male ones, whereas for metacyclic index the reverse was true. this work shows that the age limits, but does not impede metacyclogenesis of non-tene ... | 2000 | 10863619 |
| population genetics of glossina morsitans submorsitans (diptera: glossinidae). | breeding structure of glossina morsitans submorsitans newstead was evaluated by using genetic markers in mitochondrial dna where diversity was scored at two loci in five natural populations from the gambia and two populations in ethiopia (form ugandensis vanderplank), countries separated by c. 5450 km. twenty six haplotype combinations were found, of which 17 were shared among two or more populations. nine haplotypes were found in the gambia and 23 haplotypes in ethiopia. there were 12 unique ha ... | 2000 | 11020791 |
| a family of genes with growth factor and adenosine deaminase similarity are preferentially expressed in the salivary glands of glossina m. morsitans. | a cdna library constructed from salivary glands of tsetse fly, glossina morsitans morsitans (diptera: glossinidae), was differentially screened, and two related full-length cdnas were molecularly characterized: tsetse salivary growth factor, tsgf-1 and tsgf-2. the cdnas encode for open reading frames (orfs) of 494 and 506aa, respectively, and display an overall 45% amino acid identity and 61% similarity to one another. both genes are preferentially expressed in the salivary glands of male and fe ... | 2000 | 10903440 |
| study on the mechanical transmission by tsetse fly glossina morsitans centralis of trypanosoma vivax, t. congolense or t. brucei brucei to goats. | 2000 | 10643915 | |
| satellites, space, time and the african trypanosomiases. | the human and animal trypanosomiases of africa provide unique challenges to epidemiologists because of the spatial and temporal scales over which variation in transmission takes place. this chapter describes how our descriptions of the different components of transmission, from the parasites to the affected hosts, eventually developed to include geographical dimensions. it then briefly mentions two key analytical techniques used in the application of multi-temporal remotely sensed imagery to the ... | 2000 | 10997206 |
| characterisation of the loci encoding the glutamic acid and alanine rich protein of trypanosoma congolense. | we have characterised the organisation of genes encoding the glutamate and alanine rich protein (garp) surface coat of the procyclic and epimastigote stages of trypanosoma congolense in the tsetse fly. the garp genes are arranged at two, possibly physically linked, loci, one of which exhibits allelic variation. one locus contains a single garp gene, whilst both alleles of the other have a large tandem array of polycistronically transcribed garp genes. sequence analysis has revealed that there ar ... | 2000 | 10693750 |
| slender and stumpy bloodstream forms of trypanosoma brucei display a differential response to extracellular acidic and proteolytic stress. | natural infections of mammals with african trypanosomes, such as trypanosoma brucei, are generally pleomorphic, the population consisting of different forms, termed slender and stumpy forms, that vary in number as the parasitaemia develops. we show that the differentiation of slender into stumpy forms is characterized by the acquisition by the parasite of the ability to regulate its internal ph, even in the face of a large, inwardly directed gradient of h+, as well as a tolerance towards externa ... | 2000 | 10601846 |
| the distribution and epidemiology of bovine trypanosomosis in malawi. | a survey to update the distribution and clarify the epidemiology of bovine trypanosomosis in malawi was conducted between 1995-97. use was made of parasitological and serological (anti-trypanosomal antibody-detection enzyme-linked immunosorbent assay (elisa) diagnostic methods. trypanosomal infections were detected in cattle sampled adjacent to known tsetse foci. the distribution of cattle with anti-trypanosomal antibodies indicated that the distribution of bovine trypanosomosis was more widespr ... | 2000 | 10714455 |
| tissue distribution and prevalence of wolbachia infections in tsetse flies, glossina spp. | tsetse flies glossina spp. (diptera: glossinidae) harbor three different symbiotic microorganisms, one being an intracellular rickettsia of the genus wolbachia. this bacterium infects a wide range of arthropods, where it causes a variety of reproductive abnormalities, one of which is termed cytoplasmic incompatibility (ci) that, when expressed, results in embryonic death due to disruptions in fertilization events. we report here that in colonized flies, wolbachia infections can be detected in 10 ... | 2000 | 10759311 |
| chalcone, acyl hydrazide, and related amides kill cultured trypanosoma brucei brucei. | protozoan parasites of the genus trypanosoma cause disease in a wide range of mammalian hosts. trypanosoma brucei brucei, transmitted by tsetse fly to cattle, causes a disease (nagana) of great economic importance in parts of africa. t. b. brucei also serves as a model for related trypanosoma species, which cause human sleeping sickness. | 2000 | 11055585 |
| framing tropical disease in london: patrick manson, filaria perstans, and the uganda sleeping sickness epidemic, 1891-1902. | much of the historical literature on tropical medicine represents the periphery as the chief site for the production of western knowledge about disease in the british empire. this study on the filaria perstans-sleeping sickness hypothesis revises this perspective by showing how the imperial metropole functioned as a culture space for the construction of knowledge about the empire. beginning in 1891, patrick manson used the publicity resources of london to generate a rhetorical imperative for the ... | 2000 | 14535273 |
| horn fly (diptera: muscidae) saliva targets thrombin action in hemostasis. | the horn fly, hematobia irritans (l.), is an important pest of livestock because the adult stage of both sexes are aggressive blood-feeders. remarkably, even though horn fly adults feed recurrently on their hosts as ectoparasites, these flies lack the adp-responsive antiplatelet aggregation and vasodilatory antihemostatic systems described for other blood-feeding diptera. horn fly salivary gland extracts do interfere with the normal coagulation process as demonstrated by the recalcification time ... | 2000 | 15535586 |
| is sleeping sickness a circadian disorder? the serotonergic hypothesis. | patients with human african trypanosomiasis (hat, sleeping sickness), due to the inoculation of trypanosoma brucei gambiense or rhodesiense by the tsetse fly, are "sleepy by day and restless by night." the first 24 h polysomnographic recording (electroencephalogram [eeg], electromyogram [emg], electrooculogram [eog]), showing a disappearance of the 24 h rhythmicity of sleep and wakefulness, was performed in 1988. thereafter, our team recorded 18 patients and 6 control volunteers at bed rest duri ... | 1999 | 10442241 |
| resurgence of sleeping sickness in tambura county, sudan. | endemic foci of human african trypanosomiasis are present in southern sudan. in 1996 and 1997, trypanosomiasis increased sharply in tambura county. to define the magnitude and geographic distribution of the outbreak, we conducted a prevalence survey using population-based cluster sampling in 16 villages: 1,358 participants answered questions about routine activities and tsetse fly contact and received serologic testing. seroprevalence in the surveyed area was 19.4% (95% confidence interval = 16. ... | 1999 | 10463686 |
| [effect of the number of health meals before an infectious meal on the vectorial competence of glossina morsitans morsitans infected by trypanosoma congolense il 1180]. | the purpose of this work was to assess the influence of several healthy meals (0, 1 and 2) prior to the infectious one on the vectorial competence of glossina morsitans morsitans (mall). the teneral flies (< 32 h old) of this line were divided into three groups. the tsetse flies of group a received no meal. the ones of group b received one healthy meal on day 1, whereas those from group c were given two consecutive healthy meals on days 1 and 2. all the flies were experimentally infected with tr ... | 1999 | 10478424 |
| the gpi biosynthetic pathway as a therapeutic target for african sleeping sickness. | african sleeping sickness is a debilitating and often fatal disease caused by tsetse fly transmitted african trypanosomes. these extracellular protozoan parasites survive in the human bloodstream by virtue of a dense cell surface coat made of variant surface glycoprotein. the parasites have a repertoire of several hundred immunologically distinct variant surface glycoproteins and they evade the host immune response by antigenic variation. all variant surface glycoproteins are anchored to the pla ... | 1999 | 10571022 |
| [effect of the intensity of host parasitemia on the vectorial competence of glossina morsitans westwood, 1850 (mall) infected by trypanosoma (nannonmonas) congolense il 1180]. | two groups of teneral flies (aged less than 32 hours) of glossina morsitans morsitans (mall) were fed separately on two rats that had been infected with trypanosoma (nannomonas) congolense il 1180, among which one had a low parasitaemia (antilog 5.4-5.7) and the other a high parasitaemia (antilog 7.8-8.1). following to the two modes of parasitaemia, variations of the procyclic indexes were found between males and females. when both sexes were considered, it was found that the intestinal infectio ... | 1999 | 10229938 |
| breeding structure of glossina pallidipes populations evaluated by mitochondrial variation. | mitochondrial dna diversity was studied at four loci in six natural populations of the tsetse fly glossina pallidipes from zimbabwe, mozambique, kenya, and ethiopia. single-locus diversity varied from 0.39 at 12s to 0.65 at coii. a total of 32 haplotypes was found with a mean of 6.4 +/- 2.9 per locus. to study breeding structure, diversity at two loci, coii and 16s2, was evaluated in 18 populations sampled from an area of approximately 1,611,000 km2 and in three laboratory cultures. twenty-six h ... | 1999 | 10589514 |
| african trypanosomiasis in two travelers from the united states. | african trypanosomiasis is a rare but well-documented cause of fever in united states travelers returning from areas where it is endemic. we report two recently diagnosed cases that involved tourists who went on safari in tanzania. review of these and 29 other published cases indicates that disease in returning united states travelers is nearly always of the east african form, a fulminant illness for which prompt diagnosis is necessary. in the united states, timely and appropriate therapy for th ... | 1999 | 10589900 |
| [peptides as inhibitors of thrombin coagulation activity and of thrombocyte aggregation]. | the analysis of literature and our own data of regulatory peptides influence on the blood coagulation system is presenting. various natural and synthetic peptides inhibit the activity of thrombin and platelet aggregation. direct specific inhibitors of thrombin are peptides developed on the base of d-phe-pro-arg sequence. strong specific inhibitors of the prothrombinase complex factor xa were isolated from tissues and saliva of the blood-sucking organisms. these inhibitors decrease thrombin gener ... | 1999 | 10420478 |
| concordant evolution of a symbiont with its host insect species: molecular phylogeny of genus glossina and its bacteriome-associated endosymbiont, wigglesworthia glossinidia. | many arthropods with restricted diets rely on symbiotic associations for full nutrition and fecundity. tsetse flies (diptera: glossinidae) harbor three symbiotic organisms in addition to the parasitic african trypanosomes they transmit. two of these microorganisms reside in different gut cells, while the third organism is harbored in reproductive tissues and belongs to the genus wolbachia. the primary symbiont (genus wigglesworthia glossinidia) lives in differentiated epithelial cells (bacterioc ... | 1999 | 9873076 |
| history of sleeping sickness in east africa. | the history of human sleeping sickness in east africa is characterized by the appearance of disease epidemics interspersed by long periods of endemicity. despite the presence of the tsetse fly in large areas of east africa, these epidemics tend to occur multiply in specific regions or foci rather than spreading over vast areas. many theories have been proposed to explain this phenomenon, but recent molecular approaches and detailed analyses of epidemics have highlighted the stability of human-in ... | 1999 | 9880477 |
| study on the sequential tsetse-transmitted trypanosoma congolense, t. brucei brucei and t. vivax infections to african buffalo, eland, waterbuck, n'dama and boran cattle. | susceptibility of african buffalo, eland, waterbuck, n'dama and boran cattle to sequential glossina morsitans centralis-transmitted infections of trypanosoma congolense, t. brucei brucei and t. vivax was compared, and their possible role as reservoirs of these parasites for g. moristans centralis, g. pallidipes, g. austeni, g. brevipalpis and g. longipennis determined. the buffalo, eland, waterbuck and n'dama controlled t. congolense parasitaemias and were able to prevent anaemia. by contrast, o ... | 1999 | 9950344 |
| tsetse challenge, trypanosome and helminth infection in relation to productivity of village ndama cattle in senegal. | data on tsetse fly, and on village ndama cattle collected over a 4-year period in southern senegal, were analysed. a total of 431 ndama cattle in four herds of three villages in the upper casamance area of southern senegal were monitored monthly. glossina morsitans submorsitans and glossina palpalis gambiensis are present in the study area. mean tsetse apparent density was 5.4 flies/trap/day. trypanosome (trypanosoma congonlense and trypanosoma vivax) infection rate in flies was 2.4 (s.e. 0.37)% ... | 1999 | 10190867 |
| invertebrate compounds acting on the hemostatic mechanism. | physiological secretions from some invertebrates have toxic effects on mammalian blood coagulation and fibrinolytic systems. some of these effects occur because the substances contained in the secretions resemble the components of the hemostatic system. some of the substances have been characterized, and have been found to have similar molecular weights or sequences, which may indicate a common ancestry. the components can be divided into five groups: antithrombic agents (group i); inhibitors an ... | 1999 | 10192653 |
| membrane feeding glossina morsitans centralis on livestock blood and its effect on the tsetse susceptibility to pathogenic trypanosome infections. | 1999 | 10194757 | |
| the effects of a tsetse dna virus infection on the functions of the male accessory reproductive gland in the host fly glossina morsitans centralis (diptera; glossinidae). | freshly deposited third instar glossina morsitans centralis larvae were infected with the tsetse dna virus by microinjection, and at emergence adult males were separated from the females and fed on rabbit blood every second day for 8 days. a control group treated with sterile saline were handled similarly. they were dissected, and comparative observations made on the appearance and size of the accessory reproductive glands (arg) in infected and control males. regularly fed 8-day-old males from i ... | 1999 | 10341076 |
| trypanosoma brucei spp. development in the tsetse fly: characterization of the post-mesocyclic stages in the foregut and proboscis. | post-mesocyclic development of trypanosoma brucei in the tsetse fly in its migration from midgut to salivary glands, was revisited by sequential microdissection, morphometry and dna-cytofluorometry. this development started by day 6 after the infective feed, with passage of mesocyclic midgut trypomastigotes through proventriculus and upward migration along foregut and proboscis to the salivary gland ducts. kinetics of salivary gland infection showed that colonization of the salivary glands by ep ... | 1999 | 10363280 |
| extension of the prophylactic effect of isometamidium against trypanosome infections in cattle using a biodegradable copolymer. | two trials were carried out in order to compare the prophylactic effect of a subcutaneously implanted sustained release device (srd) containing a mixture of a biodegradable copolymer, poly(caprolactone-co-l-lactide), and isometamidium (ismm) with that obtained after intramuscular injection of the drug. in a first experiment under controlled conditions, two groups of cattle were treated with 0.5 mg/kg isometamidium either as a srd or intramuscularly (i.m.), and exposed at monthly intervals to glo ... | 1999 | 10379816 |
| ultrastructural localization of unique neurosecretory granules in the corpora cardiaca of the stable fly, stomoxys calcitrans, and the tsetse fly, glossina morsitans. | ultrastructural analysis of the corpora cardiaca of the stable fly, stomoxys calcitrans, and the tsetse fly, glossina morsitans, revealed the presence of elementary neurosecretory granules (eng) unique to the intrinsic neurosecretory cells (inc) of these species. in addition to electron-dense spheres, the inc of the corpus species. in addition to electron-dense spheres, the inc of the corpus cardiacum of the stable fly contain electrondense angular granules, either square or rectangular in shape ... | 1999 | 10322625 |
| genetic exchange in the trypanosomatidae. | the only trypanosomatid so far proved to undergo genetic exchange is trypanosoma brucei, for which hybrid production after co-transmission of different parental strains through the tsetse fly vector has been demonstrated experimentally. analogous mating experiments have been attempted with other trypanosoma and leishmania species, so far without success. however, natural leishmania hybrids, with a combination of the molecular characters of two sympatric species, have been described amongst both ... | 1999 | 10214689 |
| a drug incubation glossina infectivity test (digit) to assess the susceptibility of trypanosoma congolense bloodstream forms to trypanocidal drugs (xenodiagnosis). | blood was collected from two sahelian goats, experimentally infected with either a drug-sensitive cloned population of trypanosoma congolense (il 1180) or a multiple drug-resistant t. congolense stock (samorogouan/89/crta/267) and incubated at 37 degrees c for 30 min and 12 h, respectively, in the presence of different drug concentrations (0.5, 1.0, 10.0 and 100.0 microg/ml blood) of diminazene aceturate or isometamidium chloride. after that, the trypanosome/blood/drug suspensions were offered t ... | 1999 | 9924966 |
| sodalis gen. nov. and sodalis glossinidius sp. nov., a microaerophilic secondary endosymbiont of the tsetse fly glossina morsitans morsitans. | a secondary intracellular symbiotic bacterium was isolated from the haemolymph of the tsetse fly glossina morsitans morsitans and cultured in aedes albopictus cell line c6/36. pure-culture isolation of this bacterium was achieved through the use of solid-phase culture under a microaerobic atmosphere. after isolation of strain m1t, a range of tests was performed to determine the phenotypic properties of this bacterium. considering the results of these tests, along with the phylogenetic position o ... | 1999 | 10028272 |
| polymerase chain reaction characterization of trypanosomes in glossina morsitans submorsitans and g. tachinoides collected on the game ranch of nazinga, burkina faso. | the polymerase chain reaction was used to characterize the trypanosomes infecting glossina morsitans submorsitans and g. tachinoides in the game ranch of nazinga, burkina faso, situated near an agropastoral zone. dissection of 435 tsetse flies, and pcr analysis of 166 infected flies were conducted to assess the epidemiological situation. trypanosomes of the nannomonas subgenus were the most abundant in the two tsetse species (80.4% and 73.7% of identified infections in g. m. submorsitans and g. ... | 1999 | 9924962 |
| genetic differentiation of some glossina morsitans morsitans populations. | to study the population structure of glossina morsitans morsitans westwood (diptera: glossinidae), polymerase chain reaction (pcr) and singlestrand conformational polymorphism (sscp) methods were used to estimate mitochondrial dna diversity at four loci in six natural populations from zambia, zimbabwe and mozambique, and in two laboratory cultures. the zambian and zimbabwean samples were from a single fly belt. four alleles were recorded at 12s and 16s1, and five alleles at 16s2 and coi. nucleot ... | 1999 | 10608226 |
| evaluation of insecticide-treated cattle as a barrier to re-invasion of tsetse to cleared areas in northeastern zimbabwe. | a field trial in zimbabwe investigated the efficacy of insecticide-treated cattle as a barrier to prevent the re-invasion of tsetse, glossina morsitans and g. pallidipes (diptera: glossinidae), into cleared areas. the original tsetse barrier consisted of insecticide-treated odour-baited targets, at an operational density of four to five targets per km2, supported by insecticide-treatments of cattle with either deltamethrin dip (decatix, coopers) at two-weekly intervals, or deltamethrin pouron (s ... | 1999 | 10484163 |
| antigenic variation in trypanosoma brucei infections: an holistic view. | trypanosoma brucei parasites undergo clonal phenotypic (antigenic) variation to promote their transmission between mammals and tsetse-fly vectors. this process is classically considered to be a mechanism for evading humoral immune responses, but such an explanation cannot account for the high rate of switching between variable antigens or for their hierarchical (i.e. non-random) expression. i suggest that these anomalies can be explained by a new model: that antigenic variation has evolved as a ... | 1999 | 10504324 |
| n-linked glycans containing linear poly-n-acetyllactosamine as sorting signals in endocytosis in trypanosoma brucei. | african trypanosomes, such as trypanosoma brucei, are protozoan parasites that are transmitted by the tsetse fly and cause sleeping sickness in humans and nagana in cattle. trypanosomes evade the immune responses of their hosts by varying their surface coat protein (vsg) and restricting exocytosis and endocytosis to an invagination of the plasma membrane called the flagellar pocket (fp). the fp represents only 0.5% of the cellular surface but membrane turnover here occurs at high rates [1] [2] [ ... | 1999 | 10531030 |
| a structural and transcription pattern for variant surface glycoprotein gene expression sites used in metacyclic stage trypanosoma brucei. | african trypanosomes first express the variant surface glycoprotein (vsg) at the metacyclic stage in the tsetse fly vector, in preparation for transfer into the mammal. metacyclic (m)vsgs comprise a specific vsg repertoire subset and their expression is regulated differently from that of bloodstream vsgs, involving exclusively transcriptional regulation during the life cycle. to identify basic structural and functional features that may be common to mvsg telomeric transcription units, we have ch ... | 1999 | 10551359 |
| glossina morsitans morsitans and glossina palpalis palpalis: dosage compensation raises questions about the milligan model for control of trypanosome development. | evidence that dosage compensation occurs in tsetse flies was obtained by comparing the activities of x chromosome-linked enzymes, arginine phosphokinase and glucose-6-phosphate dehydrogenase in glossina m. morsitans and hexokinase and phosphoglucomutase in glossina p. palpalis, with the activity of an autosome-linked enzyme, malate dehydrogenase, in each species. the shortcomings of the x chromosome model for the control of trypanozoon maturation in tsetse are discussed in light of these finding ... | 1998 | 9806869 |
| review of tsetse flies and trypanosomosis in south africa. | the history of tsetse flies and nagana (trypanosomosis) in south africa, and especially in zululand, is reviewed. four valid tsetse fly species have been recorded from south africa. glossina morsitans morsitans disappeared from the most northerly parts of south africa during the rinderpest epizootic between 1896-1897. of the three remaining species that occurred in zululand, now part of kwazulunatal province, g. pallidipes was the most common vector of nagana in cattle, but was eradicated from t ... | 1998 | 9809324 |
| trypanotolerance, an option for sustainable livestock production in areas at risk from trypanosomosis. | trypanosomosis is one of the major constraints on animal production in areas of africa which have the greatest potential for significant increases in domestic livestock populations and livestock productivity. while the eradication of trypanosomosis from the entire continent is an unrealistic goal, considerable effort has been invested in the control of this disease through the use of trypanocidal drugs, management of the vector and exploitation of the genetic resistance exhibited by indigenous b ... | 1998 | 9638808 |
| the modified dna base beta-d-glucosyl-hydroxymethyluracil is not found in the tsetse fly stages of trypanosoma brucei. | 1998 | 9719516 | |
| molecular characterization of the principal symbiotic bacteria of the weevil sitophilus oryzae: a peculiar g + c content of an endocytobiotic dna. | the principal intracellular symbiotic bacteria of the cereal weevil sitophilus oryzae were characterized using the sequence of the 16s rdna gene (rrs gene) and g + c content analysis. polymerase chain reaction amplification with universal eubacterial primers of the rrs gene showed a single expected sequence of 1,501 bp. comparison of this sequence with the available database sequences placed the intracellular bacteria of s. oryzae as members of the enterobacteriaceae family, closely related to t ... | 1998 | 9664696 |
| selection of susceptible and refractory lines of glossina morsitans centralis for trypanosoma congolense infection and their susceptibility to different pathogenic trypanosoma species. | in a single generation of selection, two lines of glossina morsitans centralis were established that differed significantly in susceptibility to trypanosoma congolense clone il 1180. reciprocal crosses demonstrated that susceptibility was a maternally inherited trait. differences between the lines, to all phases of the trypanosome infection, were maintained for eight generations, whereas differences in susceptibility to midgut infections were maintained for twenty-eight generations. thereafter, ... | 1998 | 9824823 |
| tsetse thrombin inhibitor: bloodmeal-induced expression of an anticoagulant in salivary glands and gut tissue of glossina morsitans morsitans. | the tsetse thrombin inhibitor, a potent and specific low molecular mass (3,530 da) anticoagulant peptide, was purified previously from salivary gland extracts of glossina morsitans morsitans (diptera: glossinidae). a 303-bp coding sequence corresponding to the inhibitor has now been isolated from a tsetse salivary gland cdna library by using degenerate oligonucleotide probes. the full-length cdna contains a 26-bp untranslated segment at its 5' end, followed by a 63-bp sequence corresponding to a ... | 1998 | 9826693 |
| trypanosome infections and survival in tsetse. | the effect of trypanosome infection on vector survival was observed in a line of glossina morsitans selected for susceptibility to trypanosome infection. the differential effects of midgut and salivary gland infections on survival were examined by exposing flies to infection with either trypanosoma congolense which colonizes midgut and mouthparts or trypanosoma brucei rhodesiense which colonizes midgut and salivary glands. a comparison of the survival distributions of uninfected flies with those ... | 1998 | 9695107 |
| factors influencing the prevalence of trypanosome infection of glossina pallidipes on the ruvu flood plain of eastern tanzania. | we report the pattern of infection of glossina pallidipes with trypanosoma vivax and t. congolense at a site in the coast region of eastern tanzania, studied between november 1993 and december 1994. of the 2315 flies dissected 114 (4.9%) were t. congolense positive, 77 (3.3%) were t. vivax positive and 2 (0.1%) were t. brucei positive. fly age was determined by the pteridine fluorescence method. prevalence of infection was most strongly affected by month and the linear effect of age with the int ... | 1998 | 9698260 |
| transformation of monomorphic trypanosoma brucei bloodstream form trypomastigotes into procyclic forms at 37 degrees c by removing glucose from the culture medium. | african trypanosomes have been shown previously to undergo efficient transformation from bloodstream forms to procyclic (insect dwelling) forms in vitro by adding citrate and/or cis-aconitate to the culture medium and lowering incubation temperature to 27 degrees c. in this paper, it is shown that strain 427 monomorphic bloodstream forms of trypanosoma brucei grown in axenic culture at 37 degrees c can be transformed to procyclic forms by simply replacing the glucose carbon source in the culture ... | 1998 | 9719513 |
| [vectorial competence of glossina palpalis palpalis, glossina p. gambiensis and glossina morsitans morsitans flies for a clone of trypanosoma (nannomonas) congolense il 1180]. | the authors report on the results of experimental infections of teneral (age < 32 hours) and non-teneral (age between 80 and 96 hours) glossina palpalis palpalis, g. p. gambiensis and g. morsitans morsitans with trypanosoma congolense il 1180. flies were infected once on a parasitaemic rat. teneral flies, both sexes indiscriminate, showed a procyclic and metacyclic infection rate respectively of 0.0588 and 0.7272 for g. p. palpalis; 0.0525 and 0.0416 for g. p. gambiensis; 0.6493 and 0.7300 for g ... | 1998 | 9754312 |
| the effects of a dna virus infection on the reproductive potential of female tsetse flies, glossina morsitans centralis and glossina morsitans morsitans (diptera: glossinidae). | reproductive anomalies associated with the tsetse dna virus infection in the female tsetse hosts, glossina morsitans centralis machado and glossina morsitans morsitans westwood, inoculated with the virus during the 3rd instar larval stage were studied and the data compared to those obtained from the control females injected with sterile physiological saline. virus infected flies had significantly longer first and second pregnancy cycles (p < 0.0001) and produced pupae that were of significantly ... | 1998 | 9921317 |
| identification of stage-regulated and differentiation-enriched transcripts during transformation of the african trypanosome from its bloodstream to procyclic form. | trypanosoma brucei undergoes dramatic stage-specific changes in surface antigen expression, metabolic development, cellular morphogenesis and cell-cycle control. these events can be studied in detail during the transition between the bloodstream stumpy stage and the tsetse fly midgut procyclic form. this differentiation can be induced in vitro, is synchronous in the population and there are abundant markers for stage-regulated and differentiation events. we have used this differentiation system ... | 1998 | 9763291 |
| susceptibility to trypanosomosis of three bos indicus cattle breeds in areas of differing tsetse fly challenge. | studies to assess the differences in susceptibility to trypanosomosis among bos indicus cattle breeds (maasai zebu, orma boran and galana boran) were conducted under conditions of varying tsetse fly challenge at the nguruman escarpment in south-western kenya, for a period of 1 year. it was found that under tsetse challenge quantified as high, maasai zebu and orma boran were less susceptible than galana boran to trypanosome infections, as judged by the significantly lower incidence of infection, ... | 1998 | 9777722 |
| activity of a trypanosome metacyclic variant surface glycoprotein gene promoter is dependent upon life cycle stage and chromosomal context. | african trypanosomes evade the mammalian host immune response by antigenic variation, the continual switching of their variant surface glycoprotein (vsg) coat. vsg is first expressed at the metacyclic stage in the tsetse fly as a preadaptation to life in the mammalian bloodstream. in the metacyclic stage, a specific subset (<28; 1 to 2%) of vsg genes, located at the telomeres of the largest trypanosome chromosomes, are activated by a system very different from that used for bloodstream vsg genes ... | 1998 | 9488428 |
| on the interpretation of age-prevalence curves for trypanosome infections of tsetse flies. | epidemiological models are used to analyse 8 published data sets reporting age-prevalence curves for trypanosome infections of the tsetse fly glossina pallidipes. a model assuming a fixed maturation period and a rate of infection which is independent of fly age is adequate for trypanosoma vivax-type infections, explaining 98% of observed variance in prevalence by site and age, allowing that the rate of infection may be site dependent. this model is not adequate for t. congolense-type infections ... | 1998 | 9509024 |
| a trypanosome metacyclic vsg gene promoter with two functionally distinct, life cycle stage-specific activities. | in the mammalian bloodstream, african trypanosomes express the variant surface glycoprotein (vsg), continual switching of which allows evasion of the host immune response. bloodstream vsg genes are transcribed from polycistronic bloodstream expression sites with promoters which are located 45-60 kb upstream. these promoters are not exclusively stage-regulated, being active in the insect midgut stage where vsg is not expressed. however, the metacyclic vsg (m-vsg) genes, a small subset activated w ... | 1998 | 9518493 |
| vsg gene control and infectivity strategy of metacyclic stage trypanosoma brucei. | as the metacyclic trypanosome stage develops in the tsetse fly salivary glands, it initiates expression of variant surface glycoproteins (vsgs) and does so by each cell activating, at random, one from a small subset of metacyclic vsg (m-vsg) genes. whereas differential activation of individual vsg genes in the bloodstream occurs as a function of time, to evade waves of antibody, it is believed that the aim in the metacyclic stage is simultaneously to generate population diversity. m-vsg genes ar ... | 1998 | 9574928 |
| field evaluation of the prophylactic effect of an isometamidium sustained-release device against trypanosomiasis in cattle. | in order to compare the prophylactic effect provided by a poly(d,l-lactide) sustained-release device (srd) containing isometamidium (ismm) with that provided by the classical intramuscular injection of the drug, a field trial was carried out at the madina diassa ranch in mali. one- to 3-year-old n'dama cattle were randomly divided into three groups. the first group (n = 42) was treated with ismm at a dose of 1 mg/kg of body weight, the second group (n = 44) received the same dose of the drug via ... | 1998 | 9593118 |
| factors affecting the landing and feeding responses of the tsetse fly glossina pallidipes to a stationary ox. | in zimbabwe, studies were made of the landing and feeding responses of glossina pallidipes on an ox. of the tsetse approaching an ox, approximately 70% fed. increasing densities of tsetse increased the grooming responses of the ox but had no significant effect on the percentage of tsetse that engorged. the landing site of tsetse on the ox varied with density, with approximately 50% landing on the legs at low densities (< 20 flies per ox), compared to approximately 80% at densities > 40 flies per ... | 1998 | 9622375 |
| neuroendocrine dysfunction in african trypanosomiasis. the role of cytokines. | sleeping sickness (ss; african trypanosomiasis) is an anthropozoonosis transmitted by the tsetse fly. infection with trypanosoma brucei in humans is associated with adynamia, lethargy, anorexia, and more specifically amenorrhea/infertility in women and loss of libido/impotence in men. recent evidence suggests that experimental infection in animals with trypanosoma brucei species causes polyglandular endocrine failure by local inflammation of the pituitary, thyroid, adrenal, and gonadal glands. i ... | 1998 | 9629307 |
| olfactory sensitivity in tsetse flies: a daily rhythm. | the diurnal tsetse glossina morsitans morsitans bites especially in early morning and late afternoon; around midday feeding is at a low. in laboratory apparatus that measures the amount of locomotion under constant conditions over the photophase, the flies display a similar patterning of activity levels. the profile of daily rhythms for g. morsitans reported in the literature includes a number of motor and sensory motor systems that fluctuate cophasically. lacking is a study on the patterning of ... | 1998 | 9669048 |
| host preferences of tsetse (diptera: glossinidae) based on bloodmeal identifications. | an enzyme-linked immunosorbent assay (elisa) was developed to identify the origin of vertebrate blood in the guts of 29 245 wild-caught flies of eleven glossina species from various ecological zones of africa. depending on the quality of the bloodmeal samples, 62.8% of the samples were identified and could be assigned to a host-group (e.g. ruminant), family (e.g. bovidae) or species (e.g. bos spp.). a total of 13 145 samples (44.9%) was identifiable up to the species level. with a few exceptions ... | 1998 | 9622371 |
| factors affecting trypanosome infection rate in tsetse fly (diptera: glossinidae) populations. | wide variations in trypanosome infection rate are observed in different tsetse fly (glossina spp.) populations environmental factors and features proper to the vector, mammalian host and infecting-trypanosome species acting in the acquisition and development of infective-trypanosome infection in tsetse are examined. | 1997 | 9419848 |
| cloning and expression of a bacillus thuringiensis (l1-2) gene encoding a crystal protein active against glossina morsitans morsitans and chilo partellus. | a local isolate of bacillus thuringiensis,designated l1-2, that is toxic to chilo partellus was found to be toxic to the adult tsetse fly, glossina morsitans morsitans. the delta-endotoxin crystals derived from the isolate gave a major protein band with a molecular weight of mr 130,000-140,000 on denaturing polyacrylamide gel electrophoresis. the sequence of the cloned gene was found to be similar to that of the b. thuringiensis subsp. kurstaki hd-73 cryia(c) gene, having one amino acid differen ... | 1997 | 9003589 |
| genetics of hybridization of glossina swynnertoni with glossina morsitans morsitans and glossina morsitans centralis. | reciprocal crosses were performed with glossina swynnertoni and glossina morsitans morsitans and with g.swynnertoni and glossina morsitans centralis, using strains that carried marker genes in all three linkage groups. glossina swynnertoni males can inseminate, but not fertilize, g.m.morsitans; all other crosses produced some fertile females. hybridization did not cause sex ratio distortion among f1 flies. most f1 and backcross females were fertile, but all f1 males were sterile. sterility among ... | 1997 | 9430118 |
| the control of glossina morsitans morsitans (diptera: glossinidae) in a settled area in petauke district (eastern province, zambia) using odour-baited targets. | a trial to control g. m. morsitans with the use of 980 odour-baited, insecticide-impregnated targets was conducted in a 300 km2 area in the eastern province of zambia between 1989 and 1991. the area is highly cultivated and cattle density is high (about 8 cattle/km2). targets were deployed along roads and tracks. deployment was restricted to suitable tsetse habitat. the effect of the targets on the tsetse population and on the transmission of tsetse-transmitted trypanosomosis was monitored by me ... | 1997 | 9551476 |
| univariate analysis of tsetse habitat in the common fly belt of southern africa using climate and remotely sensed vegetation data. | tsetse are vectors of trypanosomes that cause diseases both in humans and livestock. traditional tsetse surveys, using sampling methods such as epsilon traps and black screen fly rounds, are often logistically difficult, costly and time-consuming. the distribution of tsetse, as revealed by such survey methods, is strongly influenced by environmental conditions, such as climate and vegetation cover, which may be readily mapped using satellite data. these data may be used to make predictions of th ... | 1997 | 9330253 |
| mapping tsetse habitat suitability in the common fly belt of southern africa using multivariate analysis of climate and remotely sensed vegetation data. | the distribution of glossina morsitans centralis, glossina morsitans morsitans and glossina pallidipes are described in part of southern africa, using a range of multivariate techniques applied to climate and remotely sensed vegetation data. linear discriminant analysis is limited in its predictive power by the assumption of common covariances in the classes within multivariate environment space. maximum likelihood classification is one of a variety of alternative methods that do not have this c ... | 1997 | 9330254 |