Publications

procyclin: an unusual immunodominant glycoprotein surface antigen from the procyclic stage of african trypanosomes.	an immunodominant species-specific surface glycoprotein antigen was purified from procyclic culture forms of trypanosoma brucei rhodesiense using lectin affinity chromatography and a monoclonal antibody immunoadsorbent. the purified molecule appears on a 10% polyacrylamide gel as a wide, dark silver staining band having an apparent molecular mass of between 30 and 40 kda, identical to that revealed by immunoblotting using anti-procyclic lysates. the molecule, which we have named procyclin, was s ...	1988	2464763
production of metacyclic forms by cyclical transmission of west african trypanosoma (t.) brucei isolates from man and animals.	fifteen west african trypanosoma (t.) brucei isolates from man and animals were cyclically transmitted. five stocks, belonging to the non-gambiense group, could easily be transmitted through glossina morsitans morsitans or glossina m. centralis infected on mice, whereas successful transmission of the 10 isolates, identified as trypanosoma brucei gambiense, was performed using g. palpalis gambiensis as vector. glossina p. gambiensis was infected with culture-derived procyclic trypanosomes by repe ...	1988	2467539
[house effect and family contamination in sleeping sickness: interpretative trial of the phenomenon. study of 3 congolese foci].	a review is given of the different hypotheses concerning the concentration of trypanosomiasis cases at the house or family level: 1. mechanical transmission by haematophagous insects. 2. interrupted feeding of a tsetse fly with cyclic infection on different people. 3. family biological factor. these hypotheses are used as a introduction to an epidemiological field study in three congolese foci. whereas their distribution among village districts is random, patients are significantly aggregated at ...	1988	3059954
biology of african trypanosomes in the tsetse fly.	african trypanosomes present several features of interest to cell biologists. these include: a repressible single mitochondrion with a large mass of mitochondrial dna, the kinetoplast; a special organelle, the glycosome, which houses the enzymes of the glycolytic chain; a surface coat of variable glycoprotein which enables the parasite to evade the mammalian host's immune response; and a unique flagellum-to-host attachment mechanism associated with novel cytoskeletal elements. trypanosome develo ...	1988	3067793
evolution of the secondary structures and compensatory mutations of the ribosomal rnas of drosophila melanogaster.	this paper examines the effects of dna sequence evolution on rna secondary structures and compensatory mutations. models of the secondary structures of drosophila melanogaster 18s ribosomal rna (rrna) and of the complex between 2s, 5.8s, and 28s rrnas have been drawn on the basis of comparative and energetic criteria. the overall au richness of the d. melanogaster rrnas allows the resolution of some ambiguities in the structures of both large rrnas. comparison of the sequence of expansion segmen ...	1988	3136295
[effects of sublethal doses of deltamethrin on the pair glossina morsitans morsitans-trypanosoma (nannomonas) congolense].	the presence of trypanosoma in glossina morsitans morsitans induced a decrease in the physiological activity which is expressed in particular by a statistically higher mortality rate of infected flies. a similar effect appears with sublethal doses of deltamethrin either in infected or non infected insects. a cumulative activity of both effects was also observed in infected and treated flies. sublethal doses of the pyrethroid compound showed a delay in feeding, abortions and larval clampings. mor ...	1988	3142654
[localization of trypanosoma (nannomonas) congolense broden, 1904 (kinetoplastida, trypanosomatidae) in the proboscis of glossina morsitans morsitans westwood, 1850 (diptera, glossinidae)].	transverse sections of the proboscis of g. m. morsitans infected with t. (n.) congolense initiated after a single infective blood meal were studied. trypanosomes were located in the lateral, dorso-ventral and latero-ventral regions of the food canal. parasites were also found around the whole of the circumference of the canal. such localizations influence the transmission of trypanosomes and the epidemiology of trypanosomiasis.	1988	3190120
loss of variable antigen during transformation of trypanosoma brucei rhodesiense from bloodstream to procyclic forms in the tsetse fly.	a pleomorphic line of trypanosoma brucei rhodesiense expressing a single variable antigen was used to quantify the rate of loss of the surface coat from bloodstream forms transforming to procyclics in the tsetse fly, glossina morsitans, and in in vitro culture. loss of variable antigen occurred at similar rates in the crop and anterior portion of the midgut of tsetse flies and in in vitro culture, but in the posterior portion of the fly midgut it occurred 2-3 times faster. the posterior portion ...	1988	3194363
[breeding of glossina morsitans submorsitans newstead, 1910 (diptera-glossinidae in the crta of bobo-dioulasso, burkina faso. i. adaptation of a wild strain to the laboratory breeding conditions on feeding hosts].		1988	3194566
comparative study on the susceptibility of different glossina species to trypanosoma brucei brucei infection.	teneral glossina morsitans centralis, g. austeni, g. palpalis palpalis, g. p. gambiensis, g. fuscipes fuscipes, g. tachinoides and g. brevipalpis from laboratory-bred colonies, were allowed to feed simultaneously for 34 days on the flanks of ten goats infected with trypanosoma brucei brucei isolated in tanzania or in nigeria, and then the tsetse were dissected. the seven tsetse species and subspecies showed salivary glands infections over the range of 0% to 40.4%. survival of the tanzanian and n ...	1988	3194664
detection of antigens common to salivary glands and other tissues of tsetse fly, glossina palpalis palpalis (diptera: glossinidae).	the study demonstrates the common antigens to salivary gland, fat body, mesenteron, thorax muscle, native whole body, and dried whole body homogenates of tsetse flies, g. palpalis palpalis. the possibilities of their origin and the role in hypersensitivity induction and its propagation are discussed.	1988	3198018
[trypanosoma (nannomonas) congolese broden, 1904 (kinetoplastida, trypanosomatidae) in epithelial cells of the anterior segment of the midgut of glossina morsitans morsitans westwood, 1850 (diptera, glossinidae)].		1988	3217562
[comparison of the attractive power of zébu and baoulé cattle for glossina tachinoides westwood, 1850 and glossina morsitans submorsitans newstead, 1910 in sudano-guinean savanna, burkina faso].		1988	3217566
the timing and frequency of hybrid formation in african trypanosomes during cyclical transmission.	the frequency of hybrid formation between two trypanosoma brucei clones during cyclical transmission through glossina morsitans centralis was analyzed. in two independent experiments, teneral g. m. centralis were infected with an equal mixture of two t. brucei clones showing different homozygous isoenzyme patterns for isocitrate dehydrogenase (icd; e.c.1.1.1.42) and alkaline phosphatase (ap; e.c. 3.1.3.1). trypanosomes were cyclically transmitted to mice from 23 infective flies and the subsequen ...	1988	3237678
field studies on animal trypanosomiasis in mozambique. i. effectiveness of the prophylactic drugs isometamidium chloride and pyrithidium bromide.	the efficacy of the trypanocides samorin and prothidium to protect beef cattle in areas of different trypanosome challenge was studied in muabsa, mozambique during an 18 month period. the performance of two groups of 1.5- to 3-year old bulls was observed, the first group in an area of high tsetse density, the second in an area of low to medium tsetse density. glossina morsitans and g. pallidipes were present and their respective densities were determined using standard fly rounds, a mobile elect ...	1988	3238772
selection for drug resistance in trypanosoma congolense during cyclic transmissions through glossina morsitans morsitans and drug treated rabbits.	a drug-sensitive trypanosoma congolense (il 1180 strain), with a known cd50 and cd90 (doses required to cure 50 and 90% of the infected animals) was cyclically passaged through tsetse flies. the infected flies were then fed on rabbits which received weekly prophylactic treatment of samorin. it was observed that the infections arising from flies maintained for over 60 days on drug-treated rabbits required higher curative doses to achieve a 50 and 90% cure. the results of this work suggest that a ...	1988	2896442
cultivation of the life cycle stages of trypanosoma brucei sspp.	a culture system was devised for the production of the various stages in the developmental cycle of trypanosoma brucei brucei and t. b. rhodesiense. the bloodstream forms were grown at 37 degrees c on a feeder layer of fibroblasts from embryos of microtus montanus or cd-1 mice in hepes-buffered minimum essential medium with earle's salts, supplemented with 15% heat-inactivated rabbit serum. when they were transferred to hepes-buffered cunningham's medium and incubated at 27 degrees c, they trans ...	1988	2896444
suppression of cyclical development of trypanosoma brucei brucei in glossina morsitans centralis by an anti-procyclics monoclonal antibody.	five hundred and sixty teneral male glossina morsitans centralis were fed, at the height of parasitaemia, on a goat infected with trypanosoma brucei brucei. thereafter, the tsetse were divided into 4 equal groups. group i was fed in vitro once weekly for 4 weeks and group ii twice weekly for 4 weeks on fresh defibrinated ox blood containing 2 mg/ml purified monoclonal antibody against t. b. brucei procyclics, while group iii was fed twice a week for 4 weeks on blood containing 2 mg/ml anti-t. vi ...	1988	2901200
infection rates in sterile males of morsitans, palpalis and fusca groups glossina for pathogenic trypanosoma species from east and west africa.	infection rates in sterile male glossina morsitans centralis, g. austeni, g. palpalis palpalis, g.p. gambiensis, g. fuscipes fuscipes, g. tachinoides and g. brevipalpis for trypanosoma vivax, t. congolense and t. brucei isolated from east and west africa, were studied. five groups of the sterile males, together with the five groups of sexually fertile males, of each of the respective species and subspecies were allowed to feed for 24 days on a boran calf or goats infected with t. vivax or t. con ...	1988	2901201
passive transfer of humoral resistance against adults of the tsetse fly, glossina palpalis palpalis (diptera, glossinidae), in rabbits.	the possibility of passive transfer of rabbit humoral immunity against tsetse fly bites was investigated for the first time. partial immunity of recipient animals was achieved after two intravenous injections of 15 ml of serum from immunized (donor) rabbits during 48 hrs. this treatment induced an apparent increase of resistance in the passively immunized group of rabbits expressed as direct mortality ("killing effect") of sucking flies within the following 72 hr period. the immunological state ...	1989	2488053
lectin signalling of maturation of t. congolense infections in tsetse.	the process of maturation of trypanosoma congolense broden in tsetse has been shown to be initiated by lectin secreted in the fly midgut. in the present study the duration of lectin signal required to induce maturation was determined by the sequential addition or removal of a specific lectin inhibitor (d+glucosamine) to the diet of infected male glossina morsitans westwood. an established midgut infection of t.congolense was found to require, at most, 72 h exposure to midgut lectin to begin the ...	1989	2519657
the roles of vision and olfaction in mate location by males of the tsetse fly glossina morsitans morsitans.	the roles of visual and/or olfactory stimuli in eliciting mating responses from male glossina morsitans morsitans westwood were examined, using a system for automatically recording the number and duration of mating strikes made towards decoys, under controlled conditions. the results confirm that there is no olfactory component of the female sex recognition pheromone sensed by the male antennae, and the attraction of males to females appears to be visual. the absence of male-male mating strikes ...	1989	2519658
evaluations of permethrin-impregnated clothing and three topical repellent formulations of deet against tsetse flies in zambia.	permethrin-impregnated clothing and three topical repellent formulations of deet (diethyltoluamide) were field tested against natural populations of tsetse flies, mostly glossina morsitans centralis machado, in central zambia. volunteers wore different combinations of clothing impregnated with permethrin 0.125 mg ai/cm2 and repellents while riding in a vehicle that was driven slowly (4-6 km/h), with the windows and rear door open, through fly-infested areas. the mean rate of tsetse bites was abo ...	1989	2519659
responses of tsetse flies (glossina spp.) to compounds on the skin surface of an ox: a laboratory study.	the behaviour of male glossina morsitans morsitans westwood and glossina pallidipes austen (diptera: glossinidae) alighting on targets with or without ox sebum was compared. the presence of ox sebum did not increase significantly the number of flies alighting on the target in either species. however, after contact with the sebum coated target, both species showed an increase in flight activity, and g. m.morsitans showed a greater tendency to return to the target. this behaviour resulted in a num ...	1989	2519690
purification and characterization of two fibrinolysins from the midgut of adult female glossina morsitans centralis.	1. adult female tsetse flies (glossina morsitans centralis) have at least five midgut fibrinolytic proteases, the two most active of which we have purified using de-52 cellulose. 2. the purified proteases appeared as single bands in sodium dodecylsulphate polyacrylamide gels and had mol. wts of 24,000 and 23,500 and pi values of 6.0 and 5.3, respectively. 3. both proteases hydrolyse tosyl-gly-pro-arg-pna optimally at ph 8.0 (with km of 20 and 30 microm) and were inhibited by diisopropylfluoropho ...	1989	2523272
glossina morsitans morsitans: mortalities caused in adults by experimental infection with entomopathogenic fungi.	various strains of the entomopathogenic fungi: beauveria bassiana, metarhizium anisopliae, paecilomyces fumosoroseus and p. farinosus were found to be pathogenic for adult tsetse, glossina morsitans morsitans but b. bassiana and m. anisopliae were the most pathogenic, often causing mortalities of up to 100%. dose-mortality relationships were demonstrated for both b. bassiana and m. anisopliae and male tsetse were observed to be more susceptible to infection than females. pure cultures of b. bass ...	1989	2565071
genetics of two populations of glossina morsitans centralis (diptera: glossinidae) from zambia.	glossina morsitans centralis machado was collected from the main fly belt west of mumbwa zambia and from the apparently isolated 'keembe pocket' and 11 gene-enzyme systems were examined by polyacrylamide gel electrophoresis. there were no significant differences in allele frequencies among flies collected entering a vehicle, from fly-rounds, or from f3 traps in the main fly belt. mean heterozygosity per locus is slightly higher in flies from the main fly belt than it is in flies from the 'keembe ...	1989	2566257
use of dna probes to identify trypanosoma congolense and t. simiae in tsetse flies from the gambia.	species- and strain-specific dna probes were used to identify patent midgut infections in glossina morsitans submorsitans and g. palpalis gambiensis captured at four sites in the gambia. 52% of mature nannomonas infections and 12% of immature infections were identified. trypanosoma (nannomonas) simiae accounted for the majority of identified infections in g.m. submorsitans, indicating the importance of distinguishing this species from the closely related t.(n) congolense when assessing the trypa ...	1989	2566262
isolation and cultivation in vitro to the infective, metacyclic stage of trypanosoma (nannomonas) simiae from glossina morsitans submorsitans.	two separate trypanosome isolations were made from a single nannomonas-infected glossina morsitans submorsitans from the gambia. inoculation of a piglet with the infected hypopharynx produced an infection with trypanosoma simiae. dna was isolated from the bloodstream forms to prepare a probe specific for this species. trypanosomes isolated from the fly midgut were frozen in liquid nitrogen and then cultivated in vitro. amplification of this population and elimination of a yeast contaminant were ...	1989	2566272
rickettsial infections of midgut cells are not associated with susceptibility of glossina morsitans centralis to trypanosoma congolense infection.	teneral and 30-day old non-teneral glossini morsitans centralis, from a laboratory-bred colony, were fed on a goat infected with trypanosoma congolense clone il 1180. they were then maintained on an uninfected rabbit, and dissected on day 30 after the infected feed. the midgut infection rates were 38.1% and 8.1%, with the mature infection rates of 28.7% and 4.3%, respectively. electron microscopical examination revealed the presence of rickettsia-like organisms (rlos) within the mycetomes and th ...	1989	2571249
implications of genetic exchange in the study of protozoan infections.	genetic exchange is now known to occur during the life-cycle of many parasitic protozoa, including malaria parasites, coccidia and trypanosomes. the process is studied by making deliberate crosses between cloned organisms differing in clearly defined markers. in malaria parasites, crosses have been made between parasites differing in characters such as isoenzymes, antigens and other proteins, drug sensitivity, and chromosome and other dna polymorphisms. crosses are made by transmitting a mixture ...	1989	2573031
tropical pyomyositis associated with trypanosoma brucei rhodesiense infection in a europid.	a 29-year-old european woman became infected with trypanosoma brucei rhodesiense in the luangwa valley, zambia. six days after the initial presentation of this infection she developed evidence of tropical pyomyositis (tp). these diseases, both of which are rare in europids, were satisfactorily treated. the pathogenesis of tp, which is nearly always caused by staphylococcus aureus, is undetermined. it seems possible that in this case either (i) both infections were introduced simultaneously by a ...	1989	2603212
a single trypanosome is sufficient to infect a tsetse fly.		1989	2604482
the trypanosome surface glycoprotein procyclin is expressed only on tsetse fly vector stages of the parasite.		1989	2616568
a new method for isolating trypanosoma brucei gambiense from sleeping sickness patients.	low infectivity to laboratory mammals and low virulence make trypanosoma brucei gambiense difficult to isolate and grow in amounts sufficient for biochemical characterization. we report the isolation of t.b. gambiense by feeding cryopreserved primary isolates to laboratory-reared glossina morsitans morsitans, followed by rapid cultivation in vitro of procyclic forms dissected from infected tsetse fly midguts. this technique allows the characterization of hitherto unsampled populations and avoids ...	1989	2617625
trypanosome infection rate of glossina morsitans submorsitans in bahr el arab, south darfur province, sudan.	trypanosome infection rate of glossina morsitans submorsitans in bahr el arab fly belt, sudan was investigated in four areas using fly rounds with screen and bait animals together with traps during the dry season february to may 1985. the overall infection rate of tests flies captured in the four areas was 5.1%. the infection rate of vivax group trypanosomes comprised 64.7% of total infections, congolense group 31.2% and brucei group trypanosomes 3.9%: 27.3% of the vivax and 31.3% of the congole ...	1989	2617680
review of tsetse control measures taken in the lambwe valley in 1980-1984.	during an outbreak of rhodesian sleeping sickness in the lambwe valley in 1980 initial tsetse control measures consisted of applications of dieldrin to the periphery of the ruma national park. this activity had a marked effect on the prevalence of sleeping sickness. concern about the use of dieldrin caused the cessation of this programme and justified an aerial spray programme using endosulfan. although the lambwe valley did not appear to be a good candidate for aerial spray, the endosulfan had ...	1989	2619385
mechanical transmission of trypanosoma brucei rhodesiense by glossina morsitans morsitans (diptera:glossinidae).	interrupted feedings of teneral, laboratory-reared glossina morsitans morsitans were used to study mechanical transmission of trypanosoma brucei rhodesiense. intervals between exposure of individual flies on parasitaemic rats and refeeding on clean rats were varied from five minutes to 24 hours. direct transmissions were demonstrated at each interval up to 160 minutes after exposure. proboscis dissections showed that active trypanosomes were present up to 320 minutes after exposure. no mechanica ...	1989	2619386
trypanosoma vivax: disseminated intravascular coagulation in cattle.	five crossbred cattle infected with trypanosoma vivax (likoni) by glossina morsitans developed capillary haemorrhages at the onset of parasitaemia, followed by the presence of occult blood in faecal samples and eventually melena. two animals required treatment to survive, on days 13 and 38 respectively. the other three animals cleared their parasitaemias without treatment. packed cell volume (pcv) levels decreased in all animals to levels ranging from 7.5 to 17%. relapse in a treated animal init ...	1989	2619392
natural and acquired resistance to trypanosoma vivax in cattle.	zebu x european (z x e) crossbred cattle suffered a more severe course of disease than boran cattle when infected with trypanosoma vivax (likoni) by glossina morsitans. all z x e animals in this study required berenil treatment while all borans self-cured the infection without treatment. the more severe disease in z x e animals was characterized by longer periods of patent infection and fever, more severe anaemia and greater likelihood of haemorrhage. cattle previously infected and cured with be ...	1989	2619393
procyclin gene expression and loss of the variant surface glycoprotein during differentiation of trypanosoma brucei.	in the mammalian host, the unicellular flagellate trypanosoma brucei is covered by a dense surface coat that consists of a single species of macromolecule, the membrane form of the variant surface glycoprotein (mfvsg). after uptake by the insect vector, the tsetse fly, bloodstream-form trypanosomes differentiate to procyclic forms in the fly midgut. differentiation is characterized by the loss of the mfvsg coat and the acquisition of a new surface glycoprotein, procyclin. in this study, the chan ...	1989	2645304
trypanosome sociology and antigenic variation.	survival of the trypanosome (trypanosoma brucei) population in the mammalian body depends upon paced stimulation of the host's humoral immune response by different antigenic variants and serial sacrifice of the dominant variant (homotype) so that minority variants (heterotypes) can continue the infection and each become a homotype in its turn. new variants are generated by a spontaneous switch in gene expression so that the trypanosome puts on a surface coat of a glycoprotein differing in antige ...	1989	2682484
a history of sleeping sickness in kenya.	gambian sleeping sickness entered what is now kenya from uganda in about 1901 and quickly spread along the kenyan shores and islands of lake victoria, reaching tanzania in 1902. by 1910 the disease had spread 25 miles inland along the kuja and migori rivers and their tributaries. sleeping sickness waxed and waned in these areas despite attempts to control tsetse fly populations by various methods. it was not until 1950, when the use of insecticides (ddt) applied by backpack sprayer proved succes ...	1989	2694984
effects of gamma irradiation on the midgut ultrastructure of glossina palpalis subspecies.	in the sterile insect technique, insects are sterilized prior to release in areas where they are pests. the sterile males compete for and with fertile wild individuals for mates, thus reducing the population's reproductive rate. tsetse fly (glossina spp.) populations have been eradicated after release of laboratory-bred flies sterilized by gamma irradiation. however, no studies exist on radiation-induced damage to the midgut morphology and function of the radiation-sterilized insects. after g. p ...	1989	2727263
[a community battle against a tropical endemic disease: supernatural beliefs and tsetse fly traps in the congo].	community participation in the control of tropical diseases is of major importance nowadays, particularly for sleeping sickness (gambian trypanosomiasis). indeed, the authoritarian measures used with success to control this disease during the colonial period are difficult to apply now. moreover, in the congo, cultural and financial restrictions are such that patients sometimes refuse treatment. thus, it has become highly desirable for vector control to be carried out at the same time as the trea ...	1989	2734626
mortality in adult tsetse, glossina morsitans morsitans, caused by entomopathogenic bacteria.	mortality in adult tsetse, glossina morsitans morsitans, caused by pseudomonas aeruginosa, serratia marcescens, bacillus sphaericus, bacillus cereus, bacillus thuringiensis h-14, b. thuringiensis 1, b. thuringiensis 5, b. thuringiensis var. insraelensis, and providentia rettgeri was determined. when bacteria were smeared on rabbit skin and tsetse allowed to feed only once on the contaminated area, mortality 8 days postingestion was significantly higher (p less than 0.01) in tsetse fed on p. aeru ...	1989	2738417
evidence for diploidy in metacyclic forms of african trypanosomes.	the dna contents of bloodstream form trypanosomes (life cycle stages circulating in the blood of the vertebrate host) of four african trypanosoma species and of metacyclic forms (the life cycle stage that is injected into the vertebrate by the tsetse fly during its bite) of the same four species were measured by cytofluorometry of individual cells or nuclei. the results showed unambiguously that the metacyclic forms cannot be considered to be products of meiosis containing only half of the dna o ...	1989	2748597
trypanosoma brucei: posttranscriptional control of the variable surface glycoprotein gene expression site.	the arrest of variable surface glycoprotein (vsg) synthesis is one of the first events accompanying the differentiation of trypanosoma brucei bloodstream forms into procyclic forms, which are characteristic of the insect vector. this is because of a very fast inhibition of vsg gene transcription which occurs as soon as the temperature is lowered. we report that this effect is probably not controlled at the level of transcription initiation, since the beginning of the vsg gene expression site, ab ...	1989	2779574
high frequency of antigenic variation in trypanosoma brucei rhodesiense infections.	rates at which trypanosoma brucei rhodesiense trypanosomes switch from expression of one variable antigen type (vat) to that of another have been determined in cloned populations that have been recently tsetse-fly transmitted. switching rates have been determined between several, specific pairs of vats in each population. high rates of switching were observed in 2 cloned trypanosome lines, each derived from a separate cyclical transmission of the same parental stock and each expressing a differe ...	1989	2797873
problems of field testing theoretical models: a case study.	the problems of field-testing models are discussed with reference to a population simulation model for the tsetse fly glossina pallidipes austen developed by us at nguruman in southwestern kenya. model predictions showed a reasonable fit to the changes in the biconical trap index of population size, but tended to overestimate some changes and underestimate others. a more rigorous test for the model is to manipulate one of the population parameters and compare model predictions with the observed ...	1989	2802817
vector susceptibility to african trypanosomes.	susceptibility of tsetse fly to trypanosome depends on two distinct barriers controlling respectively colonization of midgut and, migration to salivary glands. those barriers are modulated by barely known factors, pertaining to the physiological status of the fly as well as to cytoplasmic and nuclear inheritance. quantification of colonization (p) and migration (m) rates provides a way to calculate intrinsic vectorial capacity (ivc) as a product ivc = p x m, and to undergo comparative analysis o ...	1989	2802818
genomic organization, chromosomal localization, and developmentally regulated expression of the glycosyl-phosphatidylinositol-specific phospholipase c of trypanosoma brucei.	the surface of the bloodstream form of the african trypanosome, trypansoma brucei, is covered with about 10(7) molecules of the variant surface glycoprotein (vsg), a protein tethered to the plasma membrane by a glycosyl-phosphatidylinositol (gpi) membrane anchor. this anchor is cleavable by an endogenous gpi-specific phospholipase c (gpi-plc). gpi-plc activity is down regulated when trypanosomes differentiate from the bloodstream form to the procyclic form found in the tsetse fly vector. we have ...	1990	1688997
parasite kinetics and cellular responses in goats infected and superinfected with trypanosoma congolense transmitted by glossina morsitans centralis.	trypanosoma congolense infected tsetse were fed on the flanks of goats at sites drained by the prefemoral lymph node. the efferent lymphatic of this lymph node was surgically cannulated and the lymph was collected daily and examined for appearance of parasites, lymph flow and cells. trypanosomes were detected in the lymph 4 days after infection, which was 2 days prior to the appearance of the local skin reaction or the presence of parasites in the blood. once the animal became parasitaemic, tryp ...	1990	1967506
expression of resistance to isometamidium and diminazene in trypanosoma congolense in boran cattle infected by glossina morsitans centralis.	investigations were conducted on the sensitivity to isometamidium chloride (samorin) and diminazene aceturate (berenil) of derivatives of three of the trypanosoma congolense stocks isolated between 1978 and 1983 from zebu cattle in the bobo-dioulasso region of burkina faso. boran cattle were used in the drug-sensitivity tests and were infected using glossina morsitans centralis. the results showed that t. congolense stock il 2466 isolated in 1978 was sensitive to the standard therapeutic dose of ...	1990	1969704
improved identification of nannomonas infections in tsetse flies from the gambia.	trypanosomes from 36 midgut infections were isolated in procyclic culture from glossina morsitans submorsitans and g. palpalis gambiensis in the gambia. twenty-eight stocks (78%) were identified using dna probes specific for: (a) trypanosoma (nannomonas) congolense savannah type, (b) t. (n.) congolense riverine-forest type, (c) t. (n.) simiae and (d) trypanozoon, t. simiae and savannah type t. congolense were found only in g.m. submorsitans while the riverine-forest type t. congolense was restri ...	1990	1980568
evidence that the mechanism of gene exchange in trypanosoma brucei involves meiosis and syngamy.	all pairwise combinations of three cloned stocks of trypanosoma brucei (stib 247l, stib 386aa and treu 927/4) were co-transmitted through tsetse flies (glossina morsitans) and screened for the production of hybrid trypanosomes. clones of metacyclic and bloodstream trypanosomes from flies harbouring mature infections containing hybrid trypanosomes were established and screened for several isoenzyme and restriction fragment length polymorphisms. for each of the three combinations of parents, some ...	1990	1982633
formulation of pyriproxyfen, a juvenile hormone mimic, for tsetse control.	a topical dose, in 1 microliter acetone, of 0.02 microgram-2-[1-methyl-2-(4-phenoxyphenoxy) ethoxy] pyridine, the juvenile hormone mimic pyriproxyfen (s-31183, sumitomo chemical co.), caused an adult female tsetse, glossina morsitans morsitans westwood, to produce non-viable offspring for the whole of her life. using 14c labelled pyriproxyfen it was determined that as little as 0.001 microgram transferred to the in utero larva was sufficient to arrest development in the pupal stage. a formulatio ...	1990	2132975
monitoring tsetse fly populations. i. the intrinsic variability of trap catches of glossina pallidipes at nguruman, kenya.	during 1986 the tsetse fly glossina pallidipes austen was monitored daily at nguruman, southwestern kenya, using three unbaited biconical traps. this was done to investigate the nature and causes of daily variation in trap catches. the variability of the observed catches was compared to a model which includes the trapping probability and the stochastic variation in the sex-ratio. by comparing the catches of male and female flies we are able to establish the sampling distribution of the trap catc ...	1990	2132981
monitoring tsetse fly populations. ii. the effect of climate on trap catches of glossina pallidipes.	in part i it was shown that the sampling distribution of trap catches of tsetse flies, glossina pallidipes austen, at nguruman, kenya, using unbaited biconical traps follows a poisson distribution. in this paper we examine the effect of humidity and temperature on day-to-day and seasonal variations in the trap catches. it is shown that the seasonal variation is significantly correlated with maximum daily temperature, the catches increasing with temperature when the maximum temperature is below 3 ...	1990	2132982
specific probes for trypanosoma (trypanozoon) evansi based on kinetoplast dna minicircles.	trypanosoma evansi is difficult to distinguish from other members of subgenus trypanozoon, save for its inability to develop cyclically in the tsetse fly and its characteristic kinetoplast dna (kdna). we have used cloned kdna minicircle fragments as specific probes to distinguish t. evansi from other trypanosomes of subgenus trypanozoon. two probes were required, each specific for one of the subgroups of t. evansi previously described. probe a reacted only with the major isoenzyme group of t. ev ...	1990	2163493
duplicative activation mechanisms of two trypanosome telomeric vsg genes with structurally simple 5' flanks.	in the mammalian bloodstream, african trypanosomes express variant surface glycoprotein (vsg) genes from a family of long and complex telomeric expression sites. vsg switching generally occurs by the duplication of different vsg genes into these sites by gene conversion involving a series of 70 base pair (70bp) repeats in the 5' flank. in contrast, when vsg is first synthesised by trypanosomes in the tsetse fly at the metacyclic stage, a separate set of telomeric expression sites is activated. t ...	1990	2175429
[east african sleeping sickness (trypanosoma rhodesiense infection) in 2 swiss travelers to the tropics].	we report on two swiss travellers who acquired african sleeping sickness (trypanosoma rhodesiense) the same day while visiting the akagera park in rwanda. the first patient developed clinical signs of sleeping sickness 8 days after being bitten by a tsetse fly. trypanosomes were demonstrated in the blood and csf. the other patient fell ill 13 days after the bite and trypanosomes were found only in blood samples. the first patient (cerebral trypanosomiasis), was treated with melarsoprol. he devel ...	1990	2218457
the effect of intersubspecific hybridization and gamma radiation on the reproductive biology of glossina palpalis palpalis (robineau-desvoidy) and glossina palpalis gambiensis vanderplank.	the closely related tsetse fly subspecies glossina palpalis palpalis (nigeria origin) and glossina palpalis gambiensis (burkina faso origin) hybridize readily in the laboratory. hybridized g.p.palpalis females produced less offspring than the parental intrasubspecific crosses. adult emergence was below 70% with at least 78% being females. most female hybrids were fertile whereas most of the male hybrids were sterile when backcrossed to the g.p.palpalis parental line. all f1 males were capable of ...	1990	2222007
ultrastructural changes in salivary glands of tsetse, glossina morsitans morsitans, infected with virus and rickettsia-like organisms.	electron microscope observations on enlarged hypertrophied salivary glands dissected from adult laboratory-reared male glossina morsitans morsitans show a concurrent infection of the salivary gland tissue with rod-shaped virus particles and intracellular rickettsia-like organisms. the latter are found intracellular in the epithelium and in the gland lumen enclosed within lytic zones. the virus particles are found within the degenerating cytoplasm, nuclei, and lumen of the cell where they are esp ...	1990	2250102
comparison of the susceptibility to deltamethrin of female glossina morsitans morsitans westwood, 1850 (diptera: glossinidae) uninfected and infected with trypanosoma (nannomonas) congolense broden, 1904 (kinetoplastida, trypanosomatidae).	the susceptibility of pregnant female glossina morsitans morsitans westwood, 1850 infected with trypanosoma (nannomonas) congolense broden, 1904 to deltamethrin, a synthetic pyrethroid insecticide, was compared to that of pregnant uninfected females. the results showed that infected flies have a significantly higher mortality rate than uninfected ones, and have a reduced longevity compared with uninfected control flies. these experiments suggest that the effects of trypanosome infection on gloss ...	1990	2256771
[relation between tsetse fly density and bovine trypanosomiasis: the case of n'dama cattle ranching (louboulou, congo)].	the authors report the results of an entomo-parasitological survey in the state ranch of louboulou, bouenza region, congo. over a period of more than five months, the average tsetse density was 0.2 glossina palpalis palpalis captured per day and trap. although some specimens of glossina fusca congolensis were also captured, the density of the latter species was quite insignificant. no trypanosomiasis was detected among the n'dama cattle of the ranch, as a result of 114 blood samples collected fo ...	1990	2263746
first record of glossina fuscipes fuscipes newstead, 1910 and glossina morsitans submorsitans newstead, 1910 in southwestern saudi arabia.	two species of tsetse flies, glossina fuscipes fuscipes and g. morsitans submorsitans, are, for the first time, recorded from southwestern saudi arabia, near gizan. this discovery is shortly discussed in relation with the presently known distribution of these species.	1990	2291693
experimental infection of n'dama cattle with trypanosomes using glossina palpalis gambiensis caught in the wild.	the transmissibility of trypanosome infection to n'dama cattle by tsetse flies caught in the field was examined. wild-caught glossina palpalis gambiensis were transferred singly into small numbered cages and allowed to feed on 14 uninfected n'dama cattle. following a completed feed the tsetse were dissected and infection in the proboscis, the salivary glands and the gut was recorded. each animal was bitten by a number of tsetse ranging from five up to 64 flies. following dissection of the tsetse ...	1990	2321260
susceptibility of african buffalo and boran cattle to trypanosoma congolense transmitted by glossina morsitans centralis.	four african buffalo (syncerus caffer) and four boran cattle (bos indicus) were each exposed to the bites of 10 tsetse flies infected with trypanosoma congolense. although both groups of animals became infected, the buffalo showed no clinical signs of trypanosomiasis while the cattle suffered from the disease characterized by pronounced skin reactions, high parasitaemia and severe anaemia. the prepatent periods in the buffalo varied from 18 to 27 days in comparison with 11 to 14 days in the catt ...	1990	2343539
trypanosoma brucei: a membrane-associated protein in coated endocytotic vesicles.	membrane proteins were isolated from purified trypanosoma brucei coated endocytotic vesicles by phase separation with triton x-114. the largest abundant membrane protein was a doublet band with a molecular mass of about 77 kda. a specific antiserum was prepared against this protein by immunization with antigen bands excised from sodium dodecyl sulfate-polyacrylamide gels. immunoblot analyses with this antiserum showed that the 77-kda protein was present in other t. brucei, in t. congolense, and ...	1990	2404779
genetic exchange in trypanosoma brucei.	the discovery of genetic exchange in african trypanosomes belonging to the trypanosoma brucei group is an important development in our understanding of these organisms. genetic exchange is a feature of major importance in relation to population structure and speciation. furthermore, a convenient laboratory-based mating system would be of considerable value as a tool in trypanosomiasis research. it is now known that although cyclical development of trypanosomes within the tsetse fly does not requ ...	1990	15463300
unusual polymethyl alkenes in tsetse flies acting as abstinon inglossina morsitans.	the major alkene of the male tsetse fly,glossina morsitans morsitans, was isolated for characterization by thin-layer and gas chromatography (gc). the mass spectra of the alkene and the alkene dmds derivative indicated one isomer, 19,23-dimethyltritriacont-1-ene. the material is present at 1-2μg/male fly and is partially transferred to the female preparatory to or during mating. a dose-dependent antiaphrodisiac effect was seen with exposed male flies using the isolated natural product, with 2 an ...	1991	24258725
the effect of isometamidium chloride on insect forms of drug-sensitive and drug-resistant stocks of trypanosoma vivax: studies in vitro and in tsetse flies.	isometamidium chloride-resistant and -sensitive trypanosoma vivax insect forms were continuously propagated in vitro without feeder-layer cells in a semi-defined liquid medium at 27 degrees c. the effect of isometamidium chloride (samorin) on t. vivax was assessed by monitoring the viability of epimastigotes and the production of metacyclic forms. populations of insect forms of t. vivax stock il 1392 and clone il 3185 showed reduced growth and died after 10 days when cultivated in the presence o ...	1991	1994365
effect of polyclonal anti-procyclic antibodies on development of trypanosoma brucei brucei in tsetse flies.	results obtained in experiments testing the efficacy of anti-procyclic-form rabbit sera on the development of homologous and heterologous stocks of trypanosoma brucei brucei in glossina morsitans morsitans indicated that this development was affected little, or not at all, by such sera. the absence of effect of anti-procyclic stage antibodies can be explained by the failure to detect by either direct or indirect fluorescent antibody methods the presence of antibodies acquired in vivo by either t ...	1991	1994370
expression and deletion analysis of the trypanosoma brucei rhodesiense cysteine protease in escherichia coli.	trypanosoma brucei, the cause of african sleeping sickness, differentiates in the mammalian bloodstream from a long, slender trypanosome into a short, stumpy trypanosome. this event is necessary for infection of the tsetse fly and maintenance of the life cycle. we have previously shown that the stumpy form contains 10- to 15-fold-greater cysteine protease activity than either the slender form or the insect midgut procyclic, and we have isolated a cdna encoding the protease. in order to determine ...	1991	1997411
variation in resistance to isometamidium chloride and diminazene aceturate by clones derived from a stock of trypanosoma congolense.	nine clones were derived from a drug-resistant trypanosoma congolense stock (il 2856) and characterized in mice for their sensitivity to isometamidium chloride and diminazene aceturate. all clones were derived from the stock without drug selection and expressed high levels of resistance to isometamidium chloride (50% curative dose [cd50] values ranging from 1.5 to 5.1 mg/kg) and intermediate to high levels of resistance to diminazene aceturate (cd50 values ranging from 5.1 to 21.0 mg/kg). by con ...	1991	2038504
differences in sensitivity of kenyan trypanosoma vivax populations to the prophylactic and therapeutic actions of isometamidium chloride in boran cattle.	isometamidium chloride was administered as a single prophylactic dose of 0.5 mg kg-1 body weight to each of 10 boran (bos indicus) steers. at monthly intervals following drug administration, groups of five cattle each were challenged with one of two different trypanosoma vivax populations transmitted by infected glossina morsitans centralis; one with a stock (il 2982) from galana, kenya and the other with a stock (il 2986) from likoni, kenya. prophylaxis was afforded for less than one month agai ...	1991	2038768
therapeutic and prophylactic activity of isometamidium chloride against a tsetse-transmitted drug-resistant clone of trypanosoma congolense in boran cattle.	an investigation was conducted on the therapeutic and prophylactic activity of isometamidium chloride (samorinr) in boran (bos indicus) cattle against a trypanosoma congolense clone, il 3270. this clone was derived, without drug selection, from a stock originally isolated in burkina faso and has previously been shown to be resistant to isometamidium in both cattle and mice using an infection and treatment regimen. a group of 5 cattle were treated intramuscularly with 1.0 mg kg-1 isometamidium ch ...	1991	1678576
temporal changes in activity during destruction of the thoracic ventral eclosion muscle of the tsetse fly.	the spontaneous intracellular activity of the thoracic ventral longitudinal eclosion muscle (vlem) of glossina is described for the period from eclosion up to a short time before the final breakdown of recorded fibres. the vlem comprises a single motor unit with no inhibitory input. the firing frequency of the motor unit declines over 5 h after eclosion and leg release. over a period of inactivity lasting between 19-24 h in the sample fibres, there is no loss of resting membrane potential and oc ...	1991	1682956
pathogenicity of tsetse-transmitted trypanosoma congolense for waterbuck (kobus defassa) and boran cattle (bos indicus).	five waterbuck (kobus defassa) and four boran cattle (bos indicus) were infected with trypanosoma congolense il2895 using glossina morsitans morsitans. at the same time, two waterbuck and two cattle were inoculated intravenously with bloodstream forms. with both methods of challenge, cattle had short prepatent periods followed by a continuous high parasitaemia. all cattle became severely anaemic and had to be treated with trypanocidal drugs to prevent death. in contrast, tsetse and intravenous c ...	1991	1685298
infection rates in glossina morsitans morsitans fed on waterbuck and boran cattle infected with trypanosoma congolense.	teneral glossina morsitans morsitans were fed on waterbuck (kobus defassa) and boran cattle (bos indicus) infected experimentally with trypanosoma congolense clone il2895. infection rates in tsetse varied from 9 to 31% when fed on cattle, and from 2 to 59% when fed on waterbuck. in waterbuck, infections were often detected through the development of parasites in tsetse at times when parasitaemia could not be detected through microscopic examination of blood. male and female, and 1- and 2-day-old ...	1991	1685299
interaction between physiological status in n'dama cows and trypanosome infections and its effect on health and productivity of cattle in gambia.	data collected for three years on incidence of trypanosome infections, degree of anaemia as assessed by packed red cell volume (pcv) and live weights of four groups of cows of varying physiological status were analysed. the animals were not harbouring trypanosomes during a period of two to three months before exposure to periods of increasing density of tsetse flies (glossina morsitans submorsitans) while grazing in savannah woodlands. the groups of cows were formed on the following basis: pregn ...	1991	1685874
surface coat synthesis and turnover from epimastigote to bloodstream forms of trypanosoma brucei.	monoclonal antibodies to metacyclic surface coat glycoproteins of trypanosoma brucei brucei stib 247lg were produced for a study of the synthesis of metacyclic variable surface glycoproteins (vsgs) within the salivary gland of glossina morsitans morsitans, and of the first exchange of the surface glycoproteins after infection in mice. immunofluorescence antibody tests and protein a-gold labelling revealed that the vsgs are continuously integrated into the whole surface of the trypanosome while i ...	1991	1686146
a new approach to community participation in tsetse control in the busoga sleeping sickness focus, uganda. a preliminary report.	a process is described by which trapping technology is being taught to a rural community which has been affected continuously by an epidemic of sleeping sickness for over a decade. through a systematic health education programme, people are actively involved in making and setting traps and in learning about the general characteristics of the tsetse fly and the disease. a mono-screen trap has been developed for community use and is being used to trap flies. this is the first time that this kind o ...	1991	1746980
the decline of a glossina morsitans submorsitans belt in the egbe area of the derived savanna zone, kwara state, nigeria.	in the the early 1970s the egbe area of nigeria was known to be one of high trypanosomiasis risk, with four glossina species g. morsitans submorsitans newstead, g.longipalpis wiedemann, g.palpalis palpalis robineau-desvoidy and g.tachinoides westwood present. grazing by fulani pastoralists used to be short-term and only in the dry season. in recent years these pastoralists have grazed their cattle in the area throughout the year and this has prompted a reappraisal of the tsetse situation. tsetse ...	1991	1768900
structural studies on the major milk gland protein of the tsetse fly, glossina morsitans morsitans.	1. the major protein in the milk gland secretions of the tsetse fly, glossina morsitans morsitans, was isolated by a combination of gel permeation chromatography and crystallization. 2. it has a native mr approximately 47,000 and is composed of two identical polypeptide chains (mr approximately 21,000) as determined by chemical cross-linking studies. the protein has no covalently-bound carbohydrates or lipids. amino acid analysis of the protein revealed relatively high amounts of the aromatic am ...	1991	1790673
lipophorin from the tsetse fly, glossina morsitans morsitans.	1. lipophorin was isolated from the haemolymph of adult tsetse fly, glossina morsitans morsitans, by ultracentrifugation in a potassium bromide density gradient. 2. the tsetse fly lipophorin (mr congruent to 600,000) has a density of congruent to 1.11 g/ml and consists of two apoproteins, apolipophorin-i (apolp-i, mr congruent to 250,000) and apolipophorin-ii (apolp-ii, mr congruent to 80,000), both of which are glycosylated as shown by staining with periodate-schiff reagent. the protein complex ...	1991	1790674
[campaign against sleeping sickness in south-west uganda by trapping tsetse flies].	an outbreak of human trypanosomiasis due to trypanosoma brucei rhodesiense has been affecting the busoga district of uganda since 1976. more than 40,000 cases have been recorded up to 1990. since two years the epidemic area has been extending to the tororo district. the vector is glossina fuscipes. in order to stop the disease transmission a vector control project was launched in 1988 in busoga area. it is based on tsetse fly trapping, using pyramidal optic traps impregnated with deltamethrin (1 ...	1991	1793279
studies on the efficacy of deltamethrin applied to cattle for the control of tsetse flies (glossina spp.) in southern africa.	the tsetse fly (glossina spp.) inhabits 11 million km2 of africa (greekmore, 1989) where it is responsible for the transmission of trypanosomosis to man and animals. because of its slow rate of reproduction, with females producing only four to five pupae per annum, control of the tsetse fly is the best means of controlling trypanosomosis. a number of different methods have been and are used but, whilst successes have been achieved, a long term solution has not been found.	1991	1796525
modelling the probability of a single trypanosome infecting a tsetse fly.	a simple model is fitted to recent data on tsetse infection rates to estimate the probability of a single trypanosome infecting a tsetse fly. the model is extended to accommodate a possible clumping of trypanosomes in host blood.	1991	1796882
sleeping sickness and tsetse awareness: a sociological study among the tambo and lambya of the northern luangwa valley, zambia.	data on awareness of tsetse flies and knowledge of trypanosomiasis were collected in may, 1988, in the luangwa valley of isoka district in the northern province of zambia. one thousand and nine hundred adult males and females were interviewed. there was a high level of fly awareness among all the respondents, regardless of duration of residence and age groups. malaria was considered as the most serious illness in the community, and hence overshadowed the impact of trypanosomiasis in the communit ...	1991	1807810
[incidence of trypanosoma in the population of tsetse flies at the game ranch of nazinga (burkina faso)].	the frequency of trypanosome infection in glossina morsitans submorsitans and g. tachinoides, at the game ranch of nazinga (burkina faso), was examined. considering the absence of human activities and domestic animals, the study area can be considered as "primitive" and the infection rates as "natural". these results will contribute to clarifying some points concerning the epidemiology of the transmission of the parasite, in particular in those areas where the setting up of a natural game reserv ...	1991	1818363
anatomy of the parp gene promoter of trypanosoma brucei.	while growing in the tsetse fly, trypanosoma brucei expresses a major surface glycoprotein, the procyclic acidic repetitive protein (parp). the parp genes are transcribed by an alpha-amanitin-resistant rna polymerase. we have determined the sequence requirements for parp promoter activity. studies of rna produced from input dna in transiently transfected trypanosomes indicate that the rna is correctly processed by trans-splicing and polyadenylation. deletion analyses show that 330 bp are suffici ...	1991	1840521
comparative study on rickettsia-like organisms in the midgut epithelial cells of different glossina species.	the midgut epithelium of glossina morsitans centralis, g. austeni, g. pallidipes, g. palpalis palpalis, g. p. gambiensis, g. fuscipes fuscipes, g. tachinoides and g. brevipalpis from ilrad-bred colonies was examined, by electron microscopy, for the presence and distribution of rickettsia-like organisms (rlos). rlos were present in the midgut epithelial cells of all non-teneral tsetse. in g.m. centralis, g. pallidipes and, to a much lesser extent, g. brevipalpis, rlos were numerous and were prese ...	1991	1852486
rickettsia-like organisms, puparial temperature and susceptibility to trypanosome infection in glossina morsitans.	maintaining the puparial stage of successive generations of a population of tsetse 3 degrees c lower than normal reduced the numbers of rickettsia-like organisms (rlo) carried by emerging flies. the susceptibility of these flies to midgut infection with trypanosoma congolense was also significantly reduced compared with control flies held at normal temperature. these results support the view that the relationship between rlo and susceptibility is quantitative-teneral flies with heavier rlo infec ...	1991	1852487
an analysis of survey measurements of tsetse challenge to trypanotolerant cattle in relation to aspects of analytical models of trypanosomiasis.	the recent development of analytical models of trypanosomiasis has increased the general applicability of models to the strategic control of the disease. an analysis of detailed data on tsetse abundance and infection rates and trypanosome prevalence in village-based trypanotolerant cattle over 4 years in the gambia showed that seasonal patterns of abundance in glossina morsitans-infested areas were consistent, and that the rates of trypanosome infection remained relatively unchanging. however, t ...	1991	1866183
the course of experimental trypanosoma vivax infection in uda sheep.	the course of experimental trypanosoma vivax infection in eight uda rams was studied. all the infected animals became parasitaemic 2 days post-inoculation and remained so throughout the study period. a three-phase disease pattern was recognized, i.e. acute, subacute and chronic stages lasting 17-85 days. the disease was characterized by fever and a terminal decrease in rectal temperature despite an increase in parasitaemia with time for rams with acute and subacute infections. mean weight loss w ...	1991	1882495
[the distribution of the tsetse fly (diptera: glossinidae) in the humid savanna zone (central african republic). evaluation of prospective entomological techniques].	two trapping methods were compared during a survey of the distribution of tsetse flies in the mbororo cattle breeding area of the central african republic: (a) several traps dispersed throughout the riverine forest galleries and remaining only one day at each site: (b) one sentinel trap placed at the cattle drinking point and remaining for several days. the latter method was more reliable and is therefore recommended. the concentration of tsetse flies at the drinking points was negligible during ...	1991	1896769
investigation of the efficacy of flumethrin pour-on for the control of high tsetse and trypanosomiasis challenge in kenya.	the effects of bi-weekly flumethrin pour-on treatments at 1 mg kg bodyweight on tsetse fly population and trypanosome infection rates were monitored over a one-year period (2/89-2/90) in 2000 head of cattle on a trial farm, located in the lamu district in east kenya, an adjacent control farm and a transsecting road for additional fly monitoring. the tsetse fly population on the trial farm dropped from pretreatment counts of 118 flies/trap/week (feb. 1989) to 13 in june 1989 and 32 in jan. 1990. ...	1991	1896770
secondary structure constraints on the evolution of drosophila 28 s ribosomal rna expansion segments.	eukaryotic ribosomal rna genes contain rapidly evolving regions of unknown function termed expansion segments. we present the comparative analysis of the primary and secondary structure of two expansion segments from the large subunit rrna gene of ten species of drosophila and the tsetse fly species glossina morsitans morsitans. at the primary sequence level, most of the differences observed in the sequences obtained are single base substitutions. this is in marked contrast with observations in ...	1991	1904940