Publications

molecular approaches to the diagnosis of onchocerciasis.		1996	8881598
biochemical analysis, gene structure and localization of the 24 kda glutathione s-transferase from onchocerca volvulus.	survival of onchocerca volvulus, a pathogenic human filarial parasite, is likely to depend upon the detoxification activities of the glutathione s-transferases (gsts). the 24 kda o. volvulus gst, ovgst2, was expressed in a bacterial system and the recombinant protein was purified to homogeneity by affinity chromatography. specific activities of the recombinant ovgst2 (rovgst2) with a variety of substrates, and in the presence of inhibitors, were determined. with the universal substrate 1-chloro- ...	1996	8885220
cloning and characterization of cdnas encoding putative glutamate transporters from caenorhabditis elegans and onchocerca volvulus.	we report the identification and partial characterization of cdnas encoding for putative glutamate transporters from the free-living nematode caenorhabditis elegans and the filarial parasite onchocerca volvulus. glutamate transporters can be used as reliable markers for identifying cells and neurons that synaptically release glutamate and aspartate. an amplified pcr fragment containing a highly conserved amino acid heptamer found in all vertebrate glutamate transporters was used to screen a c. e ...	1996	8885221
onchocerca volvulus: identification of cdnas encoding a putative phosphatidyl-ethanolamine-binding protein and a putative partially processed mrna precursor.	we have identified and sequenced cdnas of the parasitic nematode onchocerca volvulus which encode a homologue of phosphatidylethanolamine-binding proteins from mammals. these clones are also closely related to the o. volvulus ov16 cdna (lobos et al., 1990). one identified cdna clone appears to represent a partially processed precursor. these results suggest that these cdnas are derived from a complex genomic locus, raising the possibility of polycistronic transcription in this nematode.	1996	8890735
immunohistological studies on an onchocerca volvulus ankyrin (ei).	the distribution of an onchocerca volvulus ankyrin, designated e1, was studied in different o. volvulus stages and other helminths by immunohistochemistry using rabbit antibodies raised against the recombinant e1 protein. in adult o. volvulus the protein designated e1 was localized to the extracellular clefts as well as to the cytoplasm adjacent to the cell membrane in the area of the basal labyrinth in hypodermis, intestine and uterus and to a lesser extent in oviduct and vas deferens. neuronal ...	1996	8911440
use of recombinant onchocerca volvulus antigens for diagnosis and surveillance of human onchocerciasis.	the diagnostic value of elisas based on recombinant onchocerca volvulus antigens oc 3.6 and oc 9.3 was evaluated with sera from endemic areas in west africa, guatemala and ecuador. igg assays were slightly more sensitive than those that detected igg4, and the antigen combination was significantly more sensitive than either antigen alone (oc 3.6, 93%; oc 9.3, 84%, combined 98%). these assays were also evaluated with sera from 2 villages in the onchocerciasis control programme area of west africa ...	1996	8911441
viability and fertility of adult onchocerca volvulus after 6 years of treatment with ivermectin.	onchocerca volvulus nodules were removed from 77 fully compliant patients in a longitudinal study of ivermectin treatment in sierra leone. the patients had participated in a randomized controlled trial and received either 4 annual doses of ivermectin or 10 6-monthly doses over 6 years. worms were examined 9 months after the last treatment for evidence of changes in morphology, viability and reproductivity. the findings were compared with results for the 2 groups obtained at earlier surveys of th ...	1996	8911442
onchocerca volvulus and o. lienalis: the microfilaricidal activity of moxidectin compared with that of ivermectin in vitro and in vivo.	the activity of the veterinary drug moxidectin against onchocerca volvulus and on. lienalis microfilariae (mf), both in vitro and in experimentally infected cba/ca mice, was compared with that of ivermectin. the in-vitro results demonstrated that both compounds (at a concentration of 10(-7) m) significantly reduced the mf motility index (mi) throughout the 7-day culture period and that this reduction was similar for the two compounds. mice were treated with moxidectin and ivermectin by subcutane ...	1996	8915126
ovb20, an onchocerca volvulus-cloned antigen selected by differential immunoscreening with vaccination serum in a cattle model of onchocerciasis.	a cdna of onchocerca volvulus has been isolated by differential immunoscreening of an adult worm expression library using sera raised in cattle against the related species, o. lienalis. it was selected because of its recognition by antibodies from cattle immunized with irradiated third-stage (l3) larvae and not by antibodies from animals infected with non-irradiated larvae. the original 311-bp clone was used to isolate a 1478-bp cdna. designated ovb20, this codes for 460 amino acid residues, hyb ...	1996	8920006
onchocerca volvulus-mediated keratitis: cytokine production by il-4-deficient mice.	corneal inflammation similar to human onchocercal keratitis can be induced in mice by subcutaneous immunization of a soluble extract of onchocerca volvulus (ovag) followed by direct injection of ovag into the corneal stroma. previous studies have shown that corneal pathology is associated with increased systemic and corneal th2 cytokine expression and that il-4 gene knockout (il-4-/-) mice develop less severe or no o. volvulus-mediated keratitis. the current study examined the contribution of th ...	1996	8932777
strain differentiation of onchocerca volvulus from uganda using dna probes.	polymerase chain reaction (pcr) combined with non-radioactive dna hybridization was applied for the detection and characterization of a 150 bp tandem repeat of onchocerca volvulus. dna of worms from western uganda was amplified and then probed with a digoxygenin-labelled oligonucleotide, specific for the forest form of o. volvulus and compared to samples from various african countries. hybridization was only observed with pcr products from the forest in liberia, south-eastern ghana, benin and so ...	1996	8935951
cloning of a cysteine protease required for the molting of onchocerca volvulus third stage larvae.	we have investigated the involvement of a cysteine protease in the development of onchocerca volvulus fourth stage larvae (l4) by testing the effect of cysteine protease inhibitors on the survival of third stage larvae (l3), and the molting of l3 to l4 in vitro. when larvae were cultured in the presence of specific inhibitors, the peptidyl monofluoromethylketones, viability of either l3 or l4 was not affected. however, the inhibitors reduced the number of l3 that molted to l4 in vitro in a time- ...	1996	8939969
low-molecular-weight protein ligands from onchocerca volvulus preferentially stimulate the human gammadelta t cell vdelta1+ subset.	onchocerciasis is a chronic infectious disease caused by the filarial nematode onchocerca volvulus. a minor population of human gammadelta t cells expressing vdelta1 chains is preferentially stimulated by o. volvulus ligands in vitro. therefore, the nature of the parasite ligand and the effector functions of vdelta1+ t cells stimulated by o. volvulus was investigated. a 5- to 30-kda ligand from the adult parasite lysate that is sensitive to proteinase treatment was identified. presentation for p ...	1996	8940223
in utero exposure to onchocerca volvulus: relationship to subsequent infection intensity and cellular immune responsiveness.	afro-ecuadorian individuals from an area where onchocerca volvulus is hyperendemic have been monitored for infection over the past 16 years. to determine whether in utero exposure to o. volvulus biases a child's subsequent immune responses, children (9 to 16 years old) for whom the mother's infection status was known were chosen for study. children of infected mothers (n = 19) had significantly higher levels of skin microfilariae than children of uninfected mothers (n = 13; p = 0.021). while the ...	1996	8945547
treatment of onchocerciasis.	onchocerciasis ('river blindness') has for several centuries been the scourge of people living in certain areas of the world where the disease is endemic. the treatment available up to 10 years ago, diethylcarbamazine, had very severe secondary effects. the availability of ivermectin--a well tolerated and highly effective microfilaricidal drug--has completely changed this scenario. ivermectin is now considered to be the drug of choice for the treatment of onchocerciasis. the prognosis for people ...	1996	8957156
human dirofilariasis.	subcutaneous and pulmonary dirofilariasis in humans appears to be a frequent disease in endemic areas, notably the mediterranean region. following increased air travel in recent years, the incidence of human dirofilariasis has increased in tourists as well.	1996	8970844
a novel trans-spliced mrna from onchocerca volvulus encodes a functional s-adenosylmethionine decarboxylase.	complete cdna and genomic sequences encoding the onchocerca volvulus s-adenosylmethionine decarboxylase (samdc), a key enzyme in polyamine biosynthesis, have been isolated and characterized. the deduced amino acid sequence encodes a 42 kda proenzyme with a moderate level of sequence homology to eukaryotic samdcs. enzymically active o. volvulus samdc was expressed at a high level in an escherichia coli mutant strain lacking endogenous samdc. the recombinant enzyme was purified to homogeneity usin ...	1996	8973561
rantes in onchocerciasis: changes with ivermectin treatment.	adverse reactions are seen relatively frequently after treatment of onchocerciasis patients with ivermectin. the chemokines rantes and il-8, which have both chemotactic and activation properties for eosinophils and neutrophils, respectively, may have a role in the pathogenesis of post-treatment reactions. circulating levels of the chemokines and the cytokines tumour necrosis factor-alpha (tnf-alpha) and il-6 were measured in the plasma of 22 onchocerca volvulus-infected subjects. peaks of mean c ...	1996	8973613
the novel cuticular collagen ovcol-1 of onchocerca volvulus is preferentially recognized by immunoglobulin g3 from putatively immune individuals.	the cdna sequence encoding an onchocerca volvulus collagen, ovcol-1, has been isolated and the corresponding native antigen has been identified. the cdna encodes an open reading frame of 96 amino acid residues containing an uninterrupted 66-residue gly-x-y repeat triple-helical (th) domain (where x and y may be any amino acids) flanked by a 26-residue amino non-th domain and a 4-residue carboxyl non-th domain. the size (9.7 kda) and structure of the deduced molecule are unique among previously i ...	1997	8975907
differential regulation of antigen-specific igg4 and ige antibodies in response to recombinant filarial proteins.	having identified two recombinant filarial proteins (ov27 and ovd5b) that induced patient peripheral blood mononuclear cells to produce antigen-specific igg4/ige antibodies in vitro, we assessed the role these filarial antigens play in inducing antigen-specific isotype switching (gamma 4 and epsilon) in the absence of t cells. purified cd19+ s gamma-/s epsilon- b cells were cultured with either of these antigens in the presence of anti-cd40 mab and human il-4. both antigen and polyclonal signals ...	1996	8982768
chitinase genes expressed by infective larvae of the filarial nematodes, acanthocheilonema viteae and onchocerca volvulus.	state-specific products of 220 and 75 kda were identified by metabolic labelling of infective larvae of the filarial nematode acanthocheilonema viteae in ticks. synthesis was temperature sensitive, occurring at 27 degrees c but not at 37 degrees c. these products were secreted 3-6 days after leaving the vector during post-infective development, but subsequent expression was not detected. the smaller protein with a pi of 6.2, was purified by two-dimensional electrophoresis and the n-terminal amin ...	1996	8992319
il-12 exacerbates helminth-mediated corneal pathology by augmenting inflammatory cell recruitment and chemokine expression.	corneal inflammation (keratitis) is a major cause of visual impairment in onchocerca volvulus infection. previous studies showed that onchocercal keratitis can be induced in mice following s.c. immunization and intracorneal injection with soluble o. volvulus ags (ovag), and that the inflammatory response is dependent on t cells and il-4. since recombinant il-12 impairs il-4-dependent, th2-mediated responses in other parasitic infections and in models of allergic asthma, the present study was und ...	1997	8993000
[preliminary activities of the program for the control and treatment of onchocerciasis in the yanomâmi territory, roraima, brazil].	after to characterize the clinic and epidemiological picture of the onchocerciasis in yanomâmi region, rr, brazil, begun in 1993, the national health foundation (fns) implemented a control and treatment pilot project in tootobi and balawaú. here, it was studied skin biopsies from 426 inhabitants. in the nodules of 86.7% from patients was encountered onchocerca volvulus. the over-all prevalence in the examined population was 66.2%. the treatment with ivermectin covered 80.1% of total population. ...	1996	9026835
in vivo molecular analysis of cytokines in a murine model of ocular onchocerciasis. i. up-regulation of il-4 and il-5 mrnas and not il-2 and ifn gamma mrnas in the cornea due to experimental interstitial keratitis.	sclerosing keratitis is the major cause of blindness due to onchocerciasis which results from chronic infection with the filarial parasite onchocerca volvulus. using a murine model of onchocercal sclerosing keratitis, we have demonstrated previously that predominantly (> 85%) cd3 + /cd4+ t-cells as well as the il-2 receptor bearing cells infiltrate into the cornea in vivo during development and progress of the disease. the identification of cd4+ subsets th1 and th2 based on the cytokine secretio ...	1996	9030983
adult onchocerca volvulus from east and west africa exhibit similar antigenicity with pooled sera from onchocerciasis patients.		1996	9039279
species-specific sequence in the repeat 3 region of the gene encoding a putative loa loa allergen: a diagnostic tool for occult loiasis.	a polymerase chain reaction (pcr)-based method to detect loa loa dna in the blood lysate of infected individuals is described. a set of primers was designed to amplify the repeat 3 sequence (15r3) of the gene encoding a putative l. loa allergen. the qualitative pcr was carried out using blood lysates from subjects from an l. loaendemic area of gabon where loiasis exists sympatrically with mansonella perstans, and from individuals from a loiasis-free area in togo infected concomitantly with m. pe ...	1997	9063362
onchocerciasis: clinical presentation and host parasite interactions in patients of southern sudan.	onchocerciasis, an infection by the filarial nematode onchoverca volvulus, is widely distributed in tropical africa and of great dermatologic interest. this study analyses the dermatologic presentation and tries to determine the correlations between clinical disease and host parasite interactions in onchocerciasis patients of the southern sudan.	1997	9071610
differential immune response to onchocerca volvulus: igg4 antibody responses differ in onchocerciasis patients from guatemala and ghana.	geographical differences exist in the clinical features of onchocerciasis in central america and west africa, which could be due in part from variations in the antigenic composition of the infecting organism. in an attempt to address this question, adult female worms of onchocerca volvulus derived from nodules of patients from guatemala and ghana were compared in terms of polypeptide composition and the igg4 antibody responses induced in patients. it was shown that a tris-buffer soluble extract ...	1997	9083582
occurrence and diagnosis of mansonella streptocerca in uganda.	during filaria surveys mansonella streptocerca was found for the first time in uganda, in 12 widely scattered villages in the bundibugyo district between the ruwenzori mountains and the ituri forest, an area not endemic for onchocerca volvulus. the crude prevalence in 806 examined adult persons ranged from 5 to 89% with an average of 61%. in 148 children the prevalence was 36%. the geometric mean of microfilaria (mf) densities in adult mf carriers was 1.7 mf/mg skin and the community microfilari ...	1997	9083584
identification of larval-stage-specific antigens of onchocerca volvulus uniquely recognized by putative immune sera from humans and vaccination sera from animal models.	immunity to onchocerca volvulus is indicated by the existence of putative immune individuals (pi), who do not develop patent infections or clinical symptoms after living in endemic areas for extended periods of time. to gain insight into the nature of the humoral response of pi from liberia and ecuador, their sera and those of infected individuals were investigated and compared using western blots. the antigen preparations used were extracts of third- and fourth-stage larvae (l3 and l4, respecti ...	1997	9093431
forest onchocerciasis in cameroon: its distribution and implications for selection of communities for control programmes.	the prevalence of infection and disease due to onchocerca volvulus in regions at different altitudes and distances from the nearest breeding site for the simulium vectors were studied in a forested area of cameroon. a total of 1,785 subjects in 14 villages underwent clinical and parasitological evaluation. according to who endemicity criteria, villages 267 and 720 m above the sea level (asl) were hyperendemic, whereas lower villages, at 55 n asl, were meso-endemic. altitude was positively correl ...	1997	9093432
onchocerca volvulus: striking decrease in transmission in the vina valley (cameroon) after eight annual large scale ivermectin treatments.	the impact of repeated ivermectin treatments on the transmission of onchocerca volvulus was evaluated in the vina valley, northern cameroon, by comparing the prevalence and intensity of infection observed in untreated 5-7 years old children living in the treated communities before and after 7-8 successive annual rounds of ivermectin treatment of the general population of those communities. the villages studied were ngoumi and babidan, where the initial community microfilarial loads (cmfl) were 8 ...	1997	9093638
immunopathology of onchocerciasis: a role for eosinophils in onchocercal dermatitis and keratitis.	this review has sought to demonstrate that eosinophils have an important role in the immunopathology of onchocercal dermatitis and keratitis. the most compelling evidence is the consistent presence of eosinophils and eosinophil granule proteins at the site of tissue damage, either after parasite death or direct injection of parasite antigens. a more definitive role for eosinophils in onchocercal keratitis will be determined using il-5 gene knockout mice (an animal model of onchocercal dermatitis ...	1997	9103664
black fly (diptera:simuliidae) salivary secretions: importance in vector competence and disease.	when blood-feeding, black flies introduce secretions into the feeding lesion that act in a coordinated manner on the 3 arms of the vertebrate hemostatic system (platelet aggregation, coagulation, and vasoconstriction). apyrase activity inhibits platelet aggregation and is ubiquitous in the saliva of black flies, although activity per gland varies by species and has a positive association with anthropophagy. anticoagulants target components in the final common pathway of the coagulation cascade, ...	1997	9103750
production of monoclonal antibodies against excretory-secretory products of adult male onchocerca gibsoni.	nine monoclonal antibodies (mabs) have been produced against excretory-secretory products (es) of adult male onchocerca gibsoni. these mabs fail to interact with the highly cross-reactive phosphorylcholine (pc) group and with es of the related rodent filarial parasites acanthocheilonema viteae and litomosoides carinii. eight of the mabs are of the igg isotype: 1 is an igm. three of the mabs, ogmes 4, 9, and 10, were each found by immunoprecipitation/sds-page analysis of [3h] leucine-labeled es, ...	1997	9105319
vector-parasite transmission complexes for onchocerciasis in west africa.	in west africa, there are two strains of the filarial parasite onchocerca volvulus, which differ in their ability to induce ocular disease. transmission studies have suggested that six sibling species of the parasite vector, the black fly simulium damnosum sensu lato, allow development of the two strains of o volvulus with varying efficiency. we aimed to test the hypothesis of parasite-vector complexes, whereby the two parasite strains, known as forest and savanna, are preferentially transmitted ...	1997	9111540
evaluation of serological assays for diagnosis of onchocercosis.	microscopic analysis of skin snips is the most widely used diagnostic technique for onchocercosis in endemic countries. the invasive nature and low sensitivity of that procedure has called for alternative diagnostic methods for this disease. presently, serological assays detecting filariosis in general are available for routine analysis. however, serological assays specific for onchocercosis are still not universally available. we have evaluated the performance of a dot blot assay (dba) as a pot ...	1997	9112301
field diagnosis of onchocerciasis in an area of high versus low endemicity: evaluation of the dot blot assay.	parasitological examination of skin snips is the most widely used diagnostic method for onchocerciasis, but it is associated with inconvenience and low sensitivity. we describe an inexpensive antibody-based dot blot assay (dba) for the detection of onchocerca volvulus infection. a field evaluation of this method was performed in the onchocerciasis endemic country ghana by testing 370 individuals living in a highly onchocerciasis endemic area and 122 in an area of low endemicity. sera from indivi ...	1996	9122638
structural characteristics of the ascaris allergen, aba-1.	the structure of the ascaris allergen, aba-1 was characterized at several levels. purified allergen monomers eluted from reducing page were found to reassociate into dimers in phosphate buffered saline containing 0.9 mm ca2+. this association may involve the formation of disulfide bonds between monomers. the primary amino acid sequence was used to predict secondary structure and compare the allergen to other known proteins sequences. aba-1 appears to be highly helical protein of two domains. seq ...	1995	9137643
molecular phylogenetic studies on filarial parasites based on 5s ribosomal spacer sequences.	this paper is the first large-scale molecular phylogenetic study on filarial parasites (family onchocercidae) which includes 16 species of 6 genera: brugia beaveri ash et little, 1962, b. buckleyi dissanaike et paramananthan, 1961; b. malayi (brug, 1927) buckley, 1960; b. pahangi (buckley et edeson, 1956) buckley, 1960; b. patei (buckley, nelson et heisch, 1958) buckley, 1960; b. timori partono et al, 1977; wuchereria bancrofti (cobbold, 1877) seurat, 1921: w. kalimantani palmieri. purnomo, denn ...	1994	9140481
gynaecomastia in onchocerciasis.		1997	9142073
assessment of vector microfilarial uptake as a comparatively non-invasive technique for monitoring onchocerciasis treatment campaigns in the americas.	since 1992, efforts have been made to combat onchocerciasis in guatemala through mass distribution of ivermectin. the impact of the campaign is assessed by taking skin-snips from sentinel groups within selected communities. this method gives an estimate of the prevalence and intensity of infection, and thus the efficacy of the treatment. in some communities people are becoming reluctant to volunteer for skin-snipping, and so there is a need for an alternative technique that will give quantitativ ...	1997	9171843
the diverse expression of immunity in humans at distinct states of onchocerca volvulus infection.	this study examined the development and persistence of immunity in humans presenting defined states of onchocerca volvulus infection, i.e. in exposed endemic control individuals without microfilaridermia and clinical disease, in patients with patent or post-patent onchocerciasis, and in patients concurrently infected with mansonella perstans. onchocerca volvulus antigen (ovag)-specific cellular reactivity was significantly diminished in microfilariae (mf)-positive patients, while the highest rea ...	1997	9176114
production of both ifn-gamma and il-5 by onchocerca volvulus s1 antigen-specific cd4+ t cells from putatively immune individuals.	protective immunity to the parasitic nematode onchocerca volvulus (ov) appears to be directed against molecules of invading l3 larvae. in this study, the cellular immune reaction to such an ov l3 protein (s1) which is protective in an animal model was analyzed using peripheral blood mononuclear cells (pbmc) of individuals from a hyperendemic area in west africa who were exposed to ov but remained free from disease ('putatively immune individuals'). despite seronegativity of these individuals aga ...	1997	9184917
ultrastructure of infective larvae (l3) of onchocerca volvulus (nematoda: filarioidea) developed in simulium yahense in liberia.	third-stage infective larvae of onchocerca volvulus were examined to elucidate the ultrastructure and the interrelations of the stoma, esophagus, intestine, and nervous system. the alimentary canal involves a cuticularized stoma with a triradiate lumen that is continuous with a similar triradiate lumen in the muscular region of the esophagus. the lumen wall may be laterally appressed or opened into a stellate form in the glandular region. posteriad from the esophagointestinal valve, the cylindro ...	1997	9194812
onchocerciasis hyperendemic in the unturán mountains: an extension of the endemic region in southern venezuela.	a new region with human onchocerciasis is reported in the unturán mountains, south venezuela, affecting yanomamö populations not surveyed in previous studies conducted in the venezuelan-brazilian border area. its distribution probably extends towards the upper toototobi endemic area in brazil. the age-standardized prevalence of onchocerca volvulus microfilariae (mf) (67%), the prevalence of infection in those aged > or = 20 years (86%), and the community microfilarial load (cmfl) (24 mf/mg), are ...	1997	9196753
the vector status of simulium damnosum on the island of bioko in equatorial guinea.		1997	9196754
demonstration of immunoglobulin g antibodies against onchocerca volvulus excretory-secretory antigens in different forms and stages of onchocerciasis.	the excretory-secretory (e-s) products of helminths are considered to comprise immunogenic molecules of high diagnostic value. in the present study, the serodiagnostic potential of the e-s products released in vitro by cultured female onchocerca volvulus was investigated by enzyme-linked immunosorbent assay (elisa) and western blotting using 190 serum samples from persons infected with o. volvulus and unexposed persons. the sensitivity of detection of anti-o. volvulus e-s antibodies was 94% for ...	1997	9196778
evidence for increased hydroxylation of pyrrolidone amino acid residues in the cuticle of mature onchocerca volvulus.	to determine whether morphologic changes are accompanied by variations in the biochemical and antigenic properties of the cuticle of onchocerca volvulus during development, we isolated and compared the 2-mercaptoethanol soluble cuticular proteins and the insoluble cuticlin from the predominant life-cycle stages occurring in man. sds-page analysis, before and after digestion with collagenase from achromobacter iophagus, revealed that the polypeptide composition of the 2-mercaptoethanol-solubilise ...	1997	9197461
cdna cloning of galectins from third stage larvae of the parasitic nematode teladorsagia circumcincta.	a monoclonal antibody raised to a teladorsagia circumcincta 31-33 kda doublet antigen was used to immunoscreen a t. circumcincta cdna expression library. sheep antibodies eluted from the proteins expressed by two clones immunopositive with the monoclonal antibody specifically recognised the doublet antigen on western blots of third stage larval extract, confirming that these clones coded for the antigen. database searches revealed high levels of similarity with beta-galactoside-binding lectin-li ...	1997	9200121
the anterior central nervous system of male onchocerca volvulus (nematoda:filarioidea) as a target for chemotherapy: results of an electron microscopy study.	an electron microscopy study was performed to evaluate the feasibility of the use of the anterior nerve ring of male onchocerca volvulus for the assessment of early drug effects. worms were exposed to new and known compounds at reasonable concentrations of 1 microm and less for 6, 12, 18, and 36 h in an established in vitro system. the anterior end of the filariae up to a length of 1 mm was examined and the morphological findings were compared with motility and reduction of a tetrazolium sat to ...	1997	9211505
onchocerca volvulus: immunohistochemical and immunoelectron microscopical distribution of a polyamine oxidizing enzyme.	we studied the distribution of a polyamine oxidizing enzyme (pao) in onchocerca volvulus and other nematode parasites by immunohistochemistry and electron microscopy with immunogold technique using a polyclonal antiserum raised against purified pao from ascaris suum. in adult o. volvulus the protein was localized in the outer zone and the area of the basal labyrinth of the hypodermis and occasionally in the outer zone of the uterine epithelium. further, the fluid in the body cavity was strongly ...	1997	9217703
serious reactions after mass treatment of onchocerciasis with ivermectin in an area endemic for loa loa infection.	in 1995, the world bank launched an african programme for onchocerciasis control to eliminate onchocerca volvulus disease from 19 african countries by means of community-based ivermectin treatment (cbit). several cases of encephalopathy have been reported after ivermectin in people heavily infected with microfilariae of loa loa (loiasis). we assessed the incidence of serious events in an area where onchocerciasis and loiasis are both endemic.	1997	9217715
characterization of a secreted antigen of onchocerca volvulus with host-protective potential.	a cdna designated mov2 was isolated from an onchocerca volvulus library on the basis of its product's recognition by an antiserum raised against the infective stage. immunogold electron microscopy revealed a high density of antigenic sites associated with the annulae of the l3 cuticle and with the uterine wall of the adult female: a general, low density of labelling occurred in all developmental forms. western blotting confirmed the presence of the antigen throughout the life cycle and the exist ...	1996	9223154
structural and molecular specificity of antibody responses in mice immune to third stage larvae of onchocerca volvulus.	immunization of mice with irradiated onchocerca volvulus infective stage larvae (l3) has been demonstrated to confer protection against challenge infections with these larvae. additionally, cytokine level measurements and cytokine depletion studies have shown that both il-4 and il-5 are important in generating a protective immune response against o. volvulus challenge infections, thus suggesting a dependency of protective immunity on igg1, ige and/or eosinophils. in the present study, we examine ...	1996	9223162
detection of loa loa-specific dna in blood from occult-infected individuals.	accurate and specific diagnosis of human loiasis is of crucial importance in an endemic area where two-thirds of infected individuals are without circulating microfilariae (occult loiasis). by using the polymerase chain reaction (pcr) and specific primers to the repeat 3 region (15r3) of the gene coding for loa loa 15-kda polyprotein antigen, dna was amplified from total blood lysate of occult-infected subjects. a 396-bp dna fragment was specifically detected. we tested the specificity of this m ...	1997	9225766
protective immunity induced by vaccination with onchocerca volvulus tropomyosin in rodents.	a cdna clone of onchocerca volvulus, designated mov14, and encoding 136 amino-acid residues from the c-terminus of o. volvulus tropomyosin, was evaluated as a protective immunogen in two complimentary rodent models of onchocerciasis. vaccination of balb/c mice with the recombinant fusion of mov14 coupled to maltose-binding protein (mbp) induced significant reductions (48-62%) in the recovery of onchocerca lienalis microfilariae from the skin, compared to control groups immunized with mbp alone. ...	1996	9229374
human isotype antibody responses to an onchocerca volvulus glutathione s-transferase.	human isotype specific antibody responses to a recombinant pi-class glutathione s-transferase (ov24) from onchocerca volvulus were assessed by elisa, using a large and well-characterized bank sera (n = 238) from an hyper-endemic area of moderate intensity from sierra leone. igg1, igg4 and iga responses, but neither igg2 nor ige response, to ov24 were detected in infected subjects. the relationships between ov24 antibody levels and skin microfilarial density, number of nodules, age, sex, eosinoph ...	1996	9229391
onchocerciasis and reproductive health in ecuador.	a retrospective study was performed comparing the number of spontaneous abortions in a hyperendemic area for onchocerciasis in ecuador before and after invermectin treatment with that of a comparable non-endemic area. the frequency of spontaneous abortions was associated with a change in the community microfilarial load, suggesting that there may be a relationship between spontaneous abortions and infection with onchocerca volvulus. in the endemic area, a significantly greater rate of spontaneou ...	1997	9231206
human infection with onchocerca volvulus does not affect the t helper cell phenotype of the cellular immune response to mycobacterial antigen.	in order to determine whether infection with onchocerca volvulus might modify the immune response to mycobacterial antigen, the proliferative and cytokine responses of peripheral blood mononuclear cells from 117 persons infected with o. volvulus and 36 non-endemic control subjects were compared. tuberculin-stimulated cellular proliferative responses and production of th1-type cytokines (interferon gamma) were reduced in persons infected with o. volvulus compared to controls. however, there was n ...	1997	9231215
antigenicity and specificity of very low molecular weight onchocerca volvulus polypeptides in the range 2.2-12.5 kd.	onchocerca volvulus polypeptides in the molecular mass range of 2.2 to 12.5 kd were separated by tricine-sds-page and the serological recognition of these very low molecular weight antigens (vlmw-ovag) was then investigated by immuno-blotting. sera from 21 onchocerciasis patients as well as from 53 individuals with other filariases were used to determine the sensitivity and specificity of detection of individual vlmw-ovag. in onchocerciasis patients, up to 16 vlmw-ovag were recognized predominan ...	1997	9270732
povex vector: prokaryotic expression and purification of onchocerciasis vaccine candidate antigens as fusion proteins with the 24 kd onchocerca volvulus glutathione s-transferase.	an expression vector, povex, has been designed and constructed, combining the advantages of the expression vectors pgex-3x and pjc2o. the povex vector produces a fusion protein with the 24 kd onchocerca volvulus glutathione s-transferase (ovgst2) which is easy to purify in one step from bacterial extracts under non-denaturing conditions using glutathione-sepharose chromatography. high yields of fusion protein were produced from this t7 rna polymerase-dependent expression vector, which were then ...	1997	9270737
molecular characterization and expression of onchocerca volvulus glutathione reductase.	glutathione metabolism represents a potential target for anti-parasite drug design. the central role of glutathione reductase (gr) in maintenance of the thiol redox state and in anti-oxidative defence has to be evaluated in more detail in order to establish the essential function of this enzyme for the survival of the filarial parasite onchocerca volvulus. the o. volvulus gr (ovgr) gene was cloned and sequenced. the gene is composed of 13 exons and 12 introns and spans 4065 bp. the first intron ...	1997	9271084
localization and functional analysis of the cytosolic and extracellular cuzn superoxide dismutases in the human parasitic nematode onchocerca volvulus.	this study describes the histological localization of two cuzn superoxide dismutases (sod1 and sod2) in the parasitic nematode onchocerca volvulus, and a functional characterization of the 'extracellular' form of this enzyme (sod2) which provides evidence that it is involved in the defense against environmental superoxide anion radicals. these essential enzymes are detected in larval and adult stages of the parasite, determined at the mrna and protein levels by in situ hybridization and immunolo ...	1997	9274879
recent advances in diagnosis of filarial infections.	improved diagnostic methods for human filariasis are needed to facilitate surveillance activities, to monitor control efforts and to evaluate new drugs and vaccines. currently, diagnosis of filarial infections largely depends upon detection of worms themselves, principally of microfilariae in blood or skin. in many infected people with lymphatic filariae, microfilariae (mf) are not detectable in blood, and removal of skin snips for detection of microfilariae in onchocerciasis seems a rather prim ...	1997	9279128
the entry of ivermectin and suramin into onchocerca ochengi nodules.	no currently available drug, which is safe for mass treatment, effectively kills adults of onchocerca volvulus, the causal agent of onchocerciasis in humans, or of o. ochengi, a cattle parasite used as a model of o. volvulus. since adults of both of these filarial nematodes are found in well developed nodules, the lack of efficacy of these drugs may be a result of their poor penetration into the nodules. to check if this was the problem, the distributions of the microfilaricide, ivermectin, and ...	1997	9290846
differences in cytokine responses to onchocerca volvulus extract and recombinant ov33 and ovl3-1 proteins in exposed subjects with various parasitologic and clinical states.	subjects with generalized onchocerciasis (gen), with the sowdah form, and with exposure but without onchocerciasis (endemic normal/putatively immune; en/pi) were studied for cytokine responses to onchocerca volvulus extract (ovag) and recombinant ov33 and ovl3-1 proteins. higher levels of cytokines were produced in response to ovags in sowdah and en/pi than in gen subjects. peripheral blood mononuclear cells did not produce interferon-gamma in response to antigens. ovag induced interleukin (il)- ...	1997	9291349
characterization of human immune responses to the cytosolic superoxide dismutase and glutathione s-transferase from onchocerca volvulus.	in onchocerciasis patients and in o. volvulus-exposed individuals without signs of onchocericiasis, t- and b-cell responses to two recombinantly expressed o. volvulus enzymes were analysed and compared to responses to total protein extract of adult parasites. the cytosolic enzymes cu/zn superoxide dismutase 1 (ovsod1) and glutathione s-transferase 2 (ovgst2) represent 2 detoxifying molecules which may play an important role in parasite defense against host-induced oxidative stress. the t-cell re ...	1997	9294549
identification of an epitope of a recombinant onchocerca volvulus protein that induces corneal pathology.	ocular onchocerciasis results from immune recognition of parasite proteins released into the eye by degenerating microfilariae. previous studies have shown that pathology similar to human ocular onchocerciasis can be induced in sensitized mice by intracorneal injection with onchocerca volvulus antigens. in the current study, we used this murine model to map the segments of o. volvulus protein disulfide isomerase (ovpdi) associated with the development of corneal pathology. subclones of ovpdi wer ...	1997	9297706
effect of mass treatments with ivermectin, with only partial compliance, on prevalence and intensity of o. volvulus infection in adults and in untreated 4 and 5 year-old children in burundi.	between 1991 and 1994, 4 annual treatments with ivermectin were offered to the population of an area hyperendemic for onchocerciasis in the province of bururi (burundi). in one place, kinama, the annual coverage ranged between 40 and 49% of the population. of 151 persons who were examined there in 1987 and again in 1994, 4 months after the last treatment round, 43 took ivermectin all 4 times, 34 took it 3 times, 35 twice and 17 only once. although the compliance in this population was incomplete ...	1997	9315050
localization of t and b cell stimulating domains of the immunodominant 33-kda protein of onchocerca volvulus (ov33).	the localization of t and b cell epitopes on a well characterized 33-kda protein of the filarial nematode onchocerca volvulus (ov33) was studied using peripheral blood mononuclear cells (pbmc) and sera from a total of 52 onchocerciasis patients with the generalized form of infection. a proportion of the pbmc samples proliferated in response to recombinant ov33-gst fusion protein and to fusion free ov33-6xhis. proliferative responses of patient pbmc to seven truncated ov33-6xhis polypeptides and ...	1997	9325070
pleomorphism of stromal eosinophils in murine experimental onchocercal keratitis.	onchocercal keratitis (river blindness) is one of the leading worldwide causes of blindness. light microscopic analysis of human specimens and corneal tissue from experimental models has implicated the eosinophil as an important cell in the inflammatory response. our previous studies in experimental murine onchocercal keratitis have demonstrated that the inflammatory infiltrate is composed primarily of eosinophils displaying ring shaped or bilobed nuclei. however, a number of cells were not char ...	1997	9326760
onchocerciasis in ecuador: prevalence of infection on the ecuador-colombia border in the province of esmeraldas.	the prevalence of onchocerciasis infection was determined in communities on 7 rivers located in the northern area of the canton san lorenzo, province of esmeraldas. diagnosis of the infection was obtained by skin biopsies and recombinant-antigen based-serology. no evidence of infection was detected in 9 communities studied along the rio mataje, which forms the frontier between ecuador and colombia, nor in 10 adjacent communities located on 5 interior rivers. evidence for onchocerca volvulus infe ...	1997	9332582
immunization with the cross-reactive antigens ov39 from onchocerca volvulus and hr44 from human retinal tissue induces ocular pathology and activates retinal microglia.	antigen ov39, derived from onchocerca volvulus, cross-reacts on both the t and b cell level with a nonhomologous human retinal antigen, hr44. lewis rats were immunized to investigate the potential of these antigens to induce eye disease. histologic and immunohistologic examination of ocular tissues revealed pathologic changes as early as day 12, which included induction or up-regulation of class ii and cd68-like antigen on perivascular cells, ramified retinal microglia, dendritiform cells of the ...	1997	9359736
preliminary characterisation of an onchocerca volvulus aspartic protease.	pcr using 1 primer specific for aspartic proteases and 1 primer annealing to the vector allowed amplification of a 377 bp fragment encoding part of an aspartic protease from an onchocerca volvulus cdna library. use of this fragment as a probe allowed the isolation of a larger cdna clone. in common with 2 other nematode aspartic proteases, the o. volvulus predicted protein has several of the general characteristics of this class of proteins, but lacks specific determinants of lysosomal localisati ...	1997	9363492
the ov20 protein of the parasitic nematode onchocerca volvulus. a structurally novel class of small helix-rich retinol-binding proteins.	ov20 is a major antigen of the parasitic nematode onchocerca volvulus, the causative agent of river blindness in humans, and the protein is secreted into the tissue occupied by the parasite. dna encoding ov20 was isolated, and the protein was expressed in escherichia coli. fluorescence-based ligand binding assays show that the protein contains a high affinity binding site for retinol, fluorescent fatty acids (11-((5-dimethylaminonaphthalene-1-sulfonyl)amino)undecanoic acid, dansyl-dl-alpha-amino ...	1997	9368002
characterization of a recombinant onchocerca volvulus antigen (ov33) produced in yeast.	a yeast (saccharomyces cerevisiae) expression system has been adapted to produce reagent quantities of a major onchocerca antigen, ov33. using a pool of monoclonal antibodies produced against third-stage larvae, a cdna library constructed from adult o. volvulus worms was screened. twenty-seven cdnas were isolated, two of which had sequence homology to ov33, a putative aspartyl protease inhibitor, which is the immunodominant antigen of o. volvulus. these cdnas were expressed at high levels intrac ...	1997	9392607
molecular methods for diagnosis and epidemiological studies of parasitic infections.	direct microscopy is widely used for the diagnosis of parasitic infections although it often requires an experienced microscopist for accurate diagnosis, is labour intensive and not very sensitive. in order to overcome some of these shortcomings, molecular or nucleic acid-based diagnostic methods for parasitic infections have been developed over the past 12 years. the parasites which have been studied with these techniques include the human plasmodia, leishmania, the trypanosomes, toxoplasma gon ...	1997	9394184
pcr and dna hybridization indicate the absence of animal filariae from vectors of onchocerca volvulus in uganda.	in order to identify onchocerca volvulus larvae from vectors, dna of filaria larvae from dissected blackflies was isolated, and a 150-bp long tandemly repeated dna sequence (0-150), which occurs in many onchocerca species, was amplified using polymerase chain reaction (pcr). subsequently, the pcr product was blotted onto a nylon membrane and hybridized with dna probes specific for o. volvulus or onchocerca ochengi. filaria larvae from 395 infected simulium neavei were examined and 259 samples pr ...	1997	9406774
[natural vector capacity level of simulium damnosum s.l. (diptera: simuliidae) at the ecology station of tai (côte d'ivoire)].	several studies have been carried out on the transmission of onchocerciasis by simulium damnosum s.l. in the forest zone of côte d'ivoire. this study, carried out in 1979-1980 was devoted to determine the risk of onchocerciasis transmission inside and outside the rain forest of taï (5 degrees 50' n-7 degrees 25' w). we present the vectorial capacity of s. sanctipauli in the region of taï before massive flow of refugees from areas of liberia without any control programme. the results of micromorp ...	1997	9410260
ivermectin and moxidectin in two filarial systems: resistance of monanema martini; inhibition of litomosoides sigmodontis insemination.	effects of ivermectin and moxidectin were compared on two filarial species: monanema martini which presents dermal microfilariae and induces onchocerca-like lesions in its natural murid host lemniscomys striatus, and litomosoides sigmodontis (= l. carinii). m. martini microfilariae showed an unusual resistance to ivermectin, in vitro and in vivo; moxidectin was no more efficient. however, the two drugs used at high concentrations deeply altered the uterine embryogenesis, but had no lethal effect ...	1997	9419842
comparison of the use of skin scarification and skin biopsies to determine the prevalence and intensity of onchocerca volvulus infection.	two methods for the detection of onchocerca volvulus microfilariae in the skin were compared in a population-based survey in gatete, murama and jerama, three 'collines' (administrative units) in burundi. of the 513 subjects examined, each by both methods, 131 (25.5%) were found positive by skin scarification and 119 (23.2%) by membrane filtration of the fluid in which two skin snips had been incubated. whilst the sensitivity of the two methods was similar (90% for scarifications and 82% for skin ...	1997	9425366
macrofilaricidal effects of chloroquine on adult onchocerca volvulus by local infiltration of palpable onchocercal nodules.	the macrofilaricidal effects of local infiltration of high concentrations of chloroquine into the capsule of onchocercal nodules on adult worms of onchocerca volvulus was determined. six weeks post infiltration, histological examination of single nodules showed all adult worms to be dead. with nodule conglomerates, there was localized action of chloroquine only on the adult worms in the infiltrated nodule, with no diffusion of the drug to adjacent nodules. chloroquine infiltration of young, rece ...	1997	9428184
cellular and subcellular localization of cationic leukocyte antigen (cla) in human eosinophil granulocytes.	the cellular and subcellular localization of cationic leukocyte antigen (cla) in human peripheral blood and tissue granulocytes was investigated by immunoenzymatic labeling and by immunoelectron microscopy. human peripheral blood granulocytes from healthy individuals and from subjects with eosinophilia of varying etiology, as well as intravascular and/or perivascular granulocytes in skin biopsies taken from patients with generalized onchocerciasis, a skin disease caused by microfilariae of oncho ...	1997	9428573
immunohistological studies on macrophages in lymph nodes of onchocerciasis patients after treatment with ivermectin.	the role of macrophages in the killing and elimination of microfilariae (mf) was studied immunohistologically in 14 lymph nodes from 10 patients with generalized onchocerciasis 20-68 h after treatment with a single oral dose of 150 microg/kg ivermectin. mf with signs of damage at light microscopical level were surrounded by a cellular infiltrate comprising macrophages, eosinophils and neutrophils, whereas light microscopically intact mf mostly showed no cellular reaction. resident mature macroph ...	1997	9438472
onchocerca volvulus: comparison of field collection methods for the preservation of parasite and vector samples for pcr analysis.	in recent years, methods for the identification of the filarial worm onchocerca volvulus and its vector, blackflies of the simulium damnosum complex (s. damnosum sensu lato (s.l.)), based on the amplification of parasite and vector dna sequences with the polymerase chain reaction (pcr), have been developed. routine application of these methods requires techniques for sample collection and preservation that are compatible with the limitations of field collection, yet preserve dna in a form suitab ...	1997	9447777
epilepsy, retarded growth and onchocerciasis, in two areas of different endemicity of onchocerciasis in burundi.	a high prevalence of epilepsy (up to 1.3%) was observed in an area hyperendemic for onchocerciasis in the province of bururi, burundi. following this observation, epileptics and controls were examined in 2 communes (administrative units) with different endemicity for onchocerciasis. altogether, onchocerciasis was more frequent in epileptics (81.8%) than in controls from the same households (68.3%; p < 0.05). this difference was more marked in the hyperendemic area. other possible causes of epile ...	1997	9463656
onchocera volvulus: characterization of a highly immunogenic gln-rich protein.	a pool of sera from individuals classified as putatively immune (pi) to onchocerca volvulus infection was employed in the screening of a fourth-stage larval cdna expression library. a highly immunogenic clone, encoding the ov 53/80 protein, was identified. the full length cdna of clone 4.21 contained 2527 nucleotides encoding 769 amino acids of which 100 are glutamine residues (13%). antibodies raised against recombinant protein encoded by a partial cdna sequence (clone 73-k) recognized a 53 and ...	1997	9497032
onchocerca volvulus: ultrastructural localization of two glutathione s-transferases.	glutathione s-transferases (gsts) are essential detoxification enzymes for virtually all cells and may additionally aid in parasite survival by counteracting host-induced damage. gsts from parasitic nematodes have been identified as potential targets for both immuno- and chemotherapy. to more closely characterize a 31-kda (ovgst1) and a 24.5-kda (ovgst2) gst from the pathogenic human filarial parasite onchocerca volvulus, immunolocalization by electron microscopy was performed using two distinct ...	1998	9501846
identification of a novel family of non-lysosomal aspartic proteases in nematodes.	a protein encoded by cdnas from the human parasite onchocerca volvulus and its homologs from caenorhabditis elegans and ancyclostoma caninum define a family of aspartic proteases that are most closely related to cathepsins d, but differ from them in lacking the n-glycosylation site known to be required for lysosomal targeting. the nematode proteins have a potential n-glycosylation site at the same position as mammalian cathepsins e and in common with these have atypically long n-terminal extensi ...	1998	9507052
[apropos of 5 new cases of onchocerciasis edema].	we report 5 cases of onchocerciasis presenting as limb's swelling collected in the tropical disease unit of a parisian hospital between 1982 and 1993. they are 5 men which have lived between 3 weeks and 4 years in forested areas of cameroon in four cases and côte d'ivoire in one case. the incubation period varied from 5 months to 2 years. the limb oedema was always located to one arm. it was associated with a blood eosinophilia above 2000/mm3 in 4 of 5 patients. the skin detection of microfilari ...	1997	9507765
[onchocerca volvulus--a rare cause of a mass in children].	the parasite onchocerca volvulus is well-known in its endemic areas in south and central america and west africa. it is transmitted to man by simulium flies and causes systemic infection with skin, lymphatic and ophthalmic manifestations and can cause blindness (river blindness). treatment with ivermectin is effective but sometimes there is need for surgical intervention to prevent or treat complications. we describe an 11-year-old girl, a new immigrant from ethiopia, who had a firm mass in her ...	1998	9517276
blackflies and whitewater: onchocerciasis and the eye.		1998	9532484
mast cell distribution in nodules of onchocerca volvulus from untreated patients with generalized onchocerciasis.	onchocercomata with a defined worm population were analysed to elucidate the distribution of mast cells. nodules with live females were classified according to the presence or absence of microfilariae. immunohistochemical staining was performed using antibodies specific for mast cells or ige. mast cells appeared singly or in diffuse accumulations perivascularly and in inflammatory infiltrates between adult onchocerca volvulus and in the capsular area. no mast cells were detected in cystic parts. ...	1998	9550219
thioredoxin peroxidases from brugia malayi.	parasite-derived antioxidant proteins have been implicated in playing an important role in protection against the oxygen radicals that are generated during aerobic metabolism and in defense against host immune cell attack. here we report that filarial nematodes include the thioredoxin peroxidase/thiol-specific antioxidant (tpx/tsa) family of antioxidant proteins as part of their complex defense against radical-mediated damage. at the protein level, the tpx/tsa from brugia malayi (bm-tpx-1) was a ...	1998	9566515
thioredoxin peroxidase from onchocerca volvulus: a major hydrogen peroxide detoxifying enzyme in filarial parasites.	random screening of an onchocerca volvulus third-stage (l3) cdna library identified a highly abundant cdna encoding a newly discovered antioxidant enzyme, thioredoxin peroxidase (tpx), a member of the peroxidoxin superfamily. this tpx cdna (ov-tpx-2) encodes a polypeptide of 199 amino acid residues with a calculated molecular weight of 21,890 da. the ov-tpx-2 cdna represents roughly 2.5% of the total cdnas from the l3 cdna library. the gene was expressed in escherichia coli and the protein produ ...	1998	9566516
three probable cases of loa loa encephalopathy following ivermectin treatment for onchocerciasis.	over the past nine years, more than 12 million people exposed to onchocerca volvulus infection have received at least one dose of ivermectin, almost all without serious adverse reactions. since 1991, however, several cases with neurologic manifestations, including coma, have been reported after ivermectin treatment of persons infected with o. volvulus who also had concomitant loa loa infection with very high microfilaremia (> 50,000 microfilariae/ml of blood). in 1995, four criteria were establi ...	1998	9574793
cloning and characterization of cdnas encoding beta-tubulin from dirofilaria immitis and onchocerca volvulus.	beta-tubulin is the target for the benzimidazole anthelmintics. unfortunately, none of these drugs is clinically useful against adult filariae. however, beta-tubulin has been shown to be a target for antibody-based toxicity to brugia pahangi. we cloned and characterized cdnas encoding beta-tubulin from 2 filariae, dirofilaria immitis and onchocerca volvulus, to explore possible explanations for benzimidazole insensitivity among adult filariae and the likelihood that epitopes of beta-tubulin coul ...	1998	9576511
onchocerca ochengi: assessment of the simulium vectors in north cameroon.	in the savanna areas of tropical africa, cattle are frequently infected with the filaria onchocerca ochengi. this parasite is closely related to onchocerca volvulus, the causative agent of human onchocerciasis (river blindness), and is capable of developing in the same vector, simulium damnosum s.l. in north cameroon, where both o. ochengi and o. volvulus are endemic, we carried out a field study (reported in this and 2 following papers) to examine to which extent the transmission of the 2 paras ...	1998	9585935
onchocerca ochengi: morphological identification of the l3 in wild simulium damnosum s.l., verified by dna probes.	in order to assess the prevalence of the cattle filaria onchocerca ochengi in onchocerciasis vectors (simulium damnosum s.l.) in north cameroon, we searched for a means to morphologically identify its developing larvae, which closely resemble those of o. volvulus. to this end microfilariae of the 2 onchocerca species were isolated from slaughter cattle in ngaoundéré and injected into neonate simulium species. whereas the early developmental stages (sausage stage, l2 and pre-infective larva) were ...	1998	9585936