Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| vector competence of simulium metallicum s.l. (diptera: simuliidae) in two endemic areas of human onchocerciasis in northern venezuela. | experimental infections of simulium metallicum s.l. with onchocerca volvulus were carried out in two onchocerciasis foci, altamira and trincheras, in northern venezuela, to determine vector competence. wild-caught flies, fed on infected volunteers, were maintained in the laboratory for 13-15 days at 27 degrees c. parasite development was complete but asynchronous and retarded. no differences in the vector competence of the two populations of s. metallicum s.l. were found. however, a less efficie ... | 1994 | 8192518 |
| il-4- and il-5-dependent protective immunity to onchocerca volvulus infective larvae in balb/cbyj mice. | a significant reduction in challenge worm survival occurred when balb/cbyj mice were vaccinated against onchocerca volvulus infective third stage larvae (l3) by using irradiated o. volvulus l3. challenge infections consisted of l3 implanted in diffusion chambers, which were used as a means to contain, and thus efficiently recover, the larvae from the host. the goal of the present study was to describe the mechanism of immune-mediated killing of o. volvulus l3 in diffusion chambers in mice. direc ... | 1994 | 8207236 |
| onchocerca volvulus provides ligands for the stimulation of human gamma/delta t lymphocytes expressing v delta 1 chains. | peripheral blood mononuclear cells (pbmc) from 8 onchocerciasis patients, treated or not with ivermectin, were analyzed for phenotypic cell surface markers. a significant increase (p < .05) in gamma/delta t cells expressing the v delta 1 chain compared with normal and endemic controls was detected in all patients. pbmc populations from onchocerciasis patients were not expanded after restimulation with onchocerca volvulus antigens in vitro, but both v delta 1 and v delta 2 t cells from normal don ... | 1993 | 8228357 |
| onchocerciasis and other eye problems in developing countries: a challenge for optometrists. | onchocerciasis, also known as river blindness, affects about 18 million people around the world, resulting in severe visual impairment or blindness for approximately 2 million. | 1993 | 8245390 |
| onchocerca volvulus: characterization of an immunodominant hypodermal antigen present in adult and larval parasites. | biochemical and immunological data suggest that a relatively limited number of polypeptide antigens of viable onchocerca volvulus-infective larvae are available to be recognized by the host's immune system. a partial cdna clone encoding one such antigen, designated lambda ral-2, was isolated by screening an expression cdna library with antisera raised against viable o. volvulus l3. the antigen encoded by this clone was subsequently found to be immunogenic in the majority of individuals exposed t ... | 1993 | 8253155 |
| identification of a zinc finger encoding gene in onchocerca volvulus. | eukaryotic transcription factors can be identified and classified according to conserved dna-binding motifs and conserved regulatory domains. the functional and structural analysis, and the conservation of these genes among metazoans emphasizes the importance of these dna-binding proteins in development and differentiation. in order to identify genes with common dna-binding motifs in the genome of onchocerca volvulus we have cloned a zinc finger encoding gene of the structure c2-h2. using the ca ... | 1993 | 8256086 |
| antibody responses to onchocerca volvulus in ecuadorian indians and blacks. | in ecuador, previous epidemiological studies of onchocerciasis affecting a population consisting of blacks of african origin and amerindians of the chachi tribe, have demonstrated different frequencies of clinical disease manifestations in each racial group. to explore the possibility of differential antibody responses to o. volvulus antigens in this population, a subset of sera from these two groups of ecuadorians with onchocerciasis was analyzed for antibody to o. volvulus antigens using elisa ... | 1993 | 8256087 |
| absence of sperm from the seminal receptacle of female onchocerca volvulus following multiple doses of ivermectin. | it is already known that multiple doses of ivermectin have a profound effect on embryonic development in onchocerca volvulus and that this appears to operate mainly at the single cell stage. to investigate this further, we examined adult female o. volvulus originating from patients treated either with placebo or one, four or five doses of ivermectin. the reproductive organs were dissected out of the worm and examined for evidence of oogenesis and for the quantity of sperm and oocytes in the semi ... | 1993 | 8256088 |
| the gene for the tata box-binding protein of onchocerca volvulus. | 1993 | 8264735 | |
| induction of protective immunity against larval onchocerca volvulus in a mouse model. | balb/cbyj mice were immunized against larval onchocerca volvulus by subcutaneous injection of normal, irradiated, or freeze-thaw-killed onchocerca sp. larvae. the mice received challenge infections of o. volvulus third-stage larva (l3) contained in diffusion chambers implanted subcutaneously. at two-weeks postinfection, the diffusion chambers were removed and larval survival was assessed. when mice were immunized a single time with 35-krad-irradiated or normal o. volvulus l3, there was a signifi ... | 1993 | 8279644 |
| the prevalence of antibodies to hiv-1 and hiv-2 in onchocerciasis-endemic rural areas in southern benin. | 1993 | 8280428 | |
| molecular cloning of an onchocerca volvulus extracellular cu-zn superoxide dismutase. | onchocerca volvulus, a human parasitic nematode, is the third leading cause of preventable blindness worldwide. this study describes the molecular cloning of a novel superoxide dismutase (sod) from the parasite. this putative o. volvulus extracellular sod (ovecsod) is 628 nucleotides (nt) long, including a 22-nt 5' spliced leader (sl1) and a portion encoding an n-terminal hydrophobic 42-amino-acid signal peptide. the remainder of the cdna shares 71% identity with an o. volvulus cytosolic sod seq ... | 1994 | 8300230 |
| the effects of vector control on the antibody response to antigens of onchocerca volvulus. | the effects of exposure to infective larvae on the antibody response to a cocktail of specific recombinant antigens of onchocerca volvulus and to a worm extract were evaluated by comparing the responses of individuals from a vector controlled area with those from an area of continuing transmission by elisa. individuals from the vector controlled areas were found to have reduced responses to both antigen preparations. a microfilerdermic (mf-) individuals from the area of vector control exhibited ... | 1993 | 8316433 |
| ivermectin dose assessment without weighing scales. | described are two alternatives to the weighing of patients for assessing the dose of ivermectin for use in mass chemotherapy campaigns against onchocerciasis. the first method uses height to separate patients into four dosing categories (1/2, 1, 11/2 and 2 tablets), while the second involves estimating one of these dosing categories according to an individual's physical appearance, without making any measurements. data for the height-based method were obtained from 6373 people who were taking pa ... | 1993 | 8324855 |
| survival and development of larval onchocerca volvulus in diffusion chambers implanted in primate and rodent hosts. | third-stage larvae (l3) of onchocerca volvulus were implanted in diffusion chambers in chimpanzees, mangabey monkeys, rhesus monkeys, squirrel monkeys, and inbred strains of mice, jirds, and rats for 3-63 days. at different times during the experimental period, larvae were recovered and assessed for their viability and development. survival and growth rates were equal regardless of whether the implanted larvae were fresh or cryopreserved. survival and growth rates of the larvae did not differ am ... | 1993 | 8331478 |
| efficacy of ivermectin in the treatment of concomitant mansonella perstans infections in onchocerciasis patients. | as part of an ivermectin dose-ranging study of onchocerciasis patients in togo, 55 onchocerciasis patients with concomitant mansonelliasis received single oral doses either of ivermectin (100 to 200 micrograms/kg body weight) or placebo. as expected, onchocerca volvulus microfilariae in the skin were greatly reduced in number soon after drug treatment, but microfilariae of mansonella perstans reacted differently. microfilarial densities of m. perstans were assessed with a filtration technique bo ... | 1993 | 8337736 |
| description of a computer model of forest onchocerciasis transmission and its application to field scenarios of vector control and chemotherapy. | this paper describes a computer simulation model for onchocerciasis (simon). using epidemiological and entomological data from a specific hyperendemic village in the forest area of sierra leone, the model is used to examine the effect of vector and chemotherapeutic control strategies, both separately and in combination, as well as the risk to an uninfected population caused by immigrant, infected simulium damnosum and humans. the model suggests that, in this village, the human population of abou ... | 1993 | 8346991 |
| preliminary evaluation of recombinant onchocerca volvulus antigens for serodiagnosis of onchocerciasis. | serodiagnostic assays for onchocerciasis based on native antigens are hampered by the scarcity of antigen, and they suffer from poor specificity. the present study was designed to evaluate the diagnostic utility of recently described recombinant onchocerca volvulus antigens oc 3.6 and oc 9.3 in enzyme immunoassays. the recombinant proteins were expressed as glutathione s-transferase fusions and were tested in several enzyme immunoassay formats to measure immunoglobulin g (igg) and igg4 antibodie ... | 1993 | 8349749 |
| elevated antifilarial igg4 antibody levels in microfilaremic and microfilaridermic gabonese adults and children. | immunologic analyses of sera from 47 selected individuals living in a mixed filariasis transmission zone in gabon were carried out. onchocerca volvulus, loa loa, mansonella streptocerca, and m. perstans are transmitted in this region. based on parasitologic findings and age, the 47 individuals were stratified into four groups: microfilaria negative (mf-) children (3-15 years old), mf- adults (> 15 years old), microfilaria positive (mf+) children and mf+ adults. for descriptive purposes, the term ... | 1993 | 8352386 |
| serum igg reactivity with 41-, 31-, and 28-kda larval proteins of strongyloides stercoralis in individuals with strongyloidiasis. | proteins from a deoxycholate-soluble extract of strongyloides stercoralis infective larvae were separated by sds-page, blotted onto nitrocellulose paper, and reacted with sera from individuals with confirmed s. stercoralis infections (n = 100), suspected s. stercoralis infections in whom no larvae could be detected (n = 27), and other nematode infections (40 with wuchereria bancrofti, 20 with onchocerca volvulus, 20 with necator americanus, and 20 with mixed ascaris lumbricoides and trichuris tr ... | 1993 | 8354924 |
| experimental onchocerciasis in chimpanzees: cellular responses and antigen recognition after immunization and challenge with onchocerca volvulus infective third-stage larvae. | immunization of chimpanzees with radiation-attenuated infective 3rd-stage larvae (l3) of onchocerca volvulus did not induce strong protective immunity against a subsequent challenge infection; only 1 out of 4 immunized animals remained non-patent (i.e. microfilariae-negative) after challenge, and may have been protected. however, during immunization and before challenge, a broad range of adult o. volvulus-derived antigens (ovag) and also uterus-derived ovag were recognized by circulating antibod ... | 1993 | 8356001 |
| the diagnostic antigen encoded by gene fragment dv3-14: a major sperm protein of dictyocaulus viviparus. | the dv3-14 gene fragment of dictyocaulus viviparus is 471 bp, of which about 90% is translated. the calculated molecular mass of the translation product is 15.5 kda. dna sequence homologies were found with major sperm proteins (msps) from ascaris suum, caenorhabditis elegans and onchocerca volvulus. within a segment of 62 amino acids the predicted amino acid sequence of dv3-14 shows 84% homology with an a. suum msp and 84% homology with a c. elegans msp. computer analysis of the protein sequence ... | 1993 | 8359987 |
| immunologic cross-reactivity in the pathogenesis of ocular onchocerciasis. | onchocerca volvulus, a filarial worm, is a major cause of infectious blindness and inflammatory eye disease. an autoimmune cause for ocular onchocerciasis has been suggested since the identification of a recombinant antigen of o. volvulus that shows immunologic cross-reactivity with a host ocular component of 44,000 m(r). the aim of this study was to establish the distribution of the cross-reactive antigens in both host tissues and the parasite, and to determine if significant autoantibody respo ... | 1993 | 8360022 |
| characterization of a variant tandem repeat from sudanese onchocerca volvulus. | strategies for detection and control of onchocerciasis in africa have included identification of dna probes and pcr target sequences for sensitive and specific detection of parasites. to evaluate the applicability of published pcr and dna probe based methods for the study of onchocerciasis in sudan, we collected adult o. volvulus from geographically distinct regions of sudan (700 miles apart), abu hamed (northern desert) and raja (southwestern savannah), and we examined the similarities between ... | 1993 | 8367658 |
| the population dynamics of onchocerca volvulus in the human host. | the quantitative aspects of onchocerciasis that focus on the relationship between the number of adult female onchocerca volvulus in the human host, the total numbers of microfilariae (mfs) in the body at any one time, and the numbers of infective larvae (l3) to which a person is exposed over time, have received little attention. this paper attempts to investigate the problem from three starting points:--(a) using the numbers of palpable nodules to estimate the numbers of productive female worms ... | 1993 | 8367667 |
| epidemiological studies of onchocerciasis in southern benin. | we studied the prevalence of human onchocerciasis in four geographically different regions of the southern part of benin in west africa. in a total of thirteen villages 1596 individuals were examined for clinical and parasitological signs of onchocerciasis. prevalence of microfilariae of onchocerca volvulus in skin snips was 29% in region i (lower oueme river), 64% in region ii (mono river), 56% in region iii (upper oueme river) and 70% in region iv (okpara river). based on endemicity criteria o ... | 1993 | 8367668 |
| distribution and taxonomic status of chromosomal forms of the onchocerciasis vector simulium exiguum in central ecuador. | 1993 | 8369569 | |
| cryopreservation of infective larvae of onchocerca volvulus (filarioidea: onchocercidae). | infective larvae (l3) of onchocerca volvulus were procured in liberia, west africa, in the natural black fly vector, simulium yahense. a cryobiological technique was developed to preserve l3 of o. volvulus that were fully viable after thawing. larvae were treated before cooling with 4 cryoprotective compounds. three compounds, dimethyl sulfoxide (dmso), glycerol, and ethylene glycol, were prepared with distilled water. the fourth compound was dmso prepared in different concentrations with 0.25 m ... | 1993 | 8410541 |
| viability of onchocerca volvulus in vitro. | the use of a selective schedule of tests to identify a viable population of isolated adult onchocerca volvulus (nematoda: filarioidea) has been investigated in a large worm population. the study was initiated to develop methodology appropriate to test new candidate macrofilaricides for their in vitro activity against o. volvulus. after removal from the host the viability of isolated intact parasites was estimated by assessing the motility indices of male worms, and the colorimetric quantificatio ... | 1993 | 8414672 |
| the filarial antigens av33/ov33-3 show striking similarities to the major pepsin inhibitor from ascaris suum. | 1993 | 8433724 | |
| a sensitive serodiagnostic test for onchocerciasis using a cocktail of recombinant antigens. | a specific serodiagnostic test for onchocerciasis has been a priority objective of the world health organization. fragments of cdna encoding onchocerca volvulus antigens selected on the basis of their specificity for this parasite were subcloned into a protein purification and expression system. no individual recombinant antigen showed a high sensitivity in an enzyme-linked immunosorbent assay because of heterogeneity in the response of o. volvulus-infected individuals. however, a cocktail of th ... | 1993 | 8447523 |
| characterization of a recombinant t cell and b cell reactive polypeptide of onchocerca volvulus. | to identify potentially protective ag of the filarial nematode onchocerca volvulus on the molecular level we screened a cdna library of o. volvulus with a human serum raised against radiation-attenuated infective larvae of o. volvulus. a cdna clone of 218 bp (ovl3-1) was selected for further studies. it was expressed in escherichia coli and affinity purified recombinant polypeptide was tested for its ability to stimulate in vitro pbmc from african onchocerciasis patients and pbmc from chimpanzee ... | 1993 | 8454865 |
| glutamine-supported motility of adult filarial parasites in vitro and the effect of glutamine antimetabolites. | the survival in culture of adult female brugia pahangi, acanthocheilonema viteae, and onchocerca volvulus and adult male onchocerca gibsoni was assessed by measuring parasite motility. survival of all species was maximal in a nutritionally complex medium (rpmi-1640). all species survived for up to 48 hr in a simpler medium in which the only energy source was 10 mm glutamine; motility in this medium was dependent upon ph. for the species of onchocerca, motility was maintained better in the presen ... | 1993 | 8459326 |
| characterization of the onchocerca volvulus superoxide dismutase gene and mrna processing. | 1993 | 8459831 | |
| molecular cloning and expression of smirv1, a schistosoma mansoni antigen with similarity to calnexin, calreticulin, and ovral1. | protective immunity against schistosomiasis induced by vaccination of mice with irradiated cercaria can be passively transferred to uninfected mice with sera or igg. antigens that are uniquely or more strongly recognized by such protective sera compared with sera from infected unprotected mice have been identified previously. two genes, smirv1 and smirv5, were selected from an adult worm cdna library by screening with antibodies raised against these candidate vaccine proteins. active immunizatio ... | 1993 | 8463298 |
| an immunohistochemical analysis of onchocercal nodules: evidence for an interaction between macrophage mrp8/mrp14 and adult onchocerca volvulus. | we have used a panel of moabs to investigate the phenotype of macrophages and other leucocytes infiltrating onchocercal nodules. nodules were removed from individuals at the end of the second year of a community-based, placebo-controlled trial of annual ivermectin chemotherapy in northern nigeria. no significant differences were seen in the distribution and phenotype of leucocytes in nodules from ivermectin- and placebo-treated individuals. live adult worms were only seen in nine of the 21 nodul ... | 1993 | 8467568 |
| structure and homology of human c1q receptor (collectin receptor). | in this paper we report partial amino acid sequence for c1q receptor (c1qr). the n-terminal amino acid sequence of isolated c1qr and the sequences of peptides obtained by v8/trypsin digestion show a high degree of similarity to the cdna-derived amino acid sequence of a human protein which was initially reported as a component of rossa and subsequently as calreticulin. this sequence in turn shows homology with onchocerca volvulus antigen (ral-1) and b50 murine melanoma antigen. a component of app ... | 1993 | 8478019 |
| design of onchocerca dna probes based upon analysis of a repeated sequence family. | repeated dna sequences have been instrumental in the development of dna probes for many different parasites. isolation of such dna probes has generally been accomplished by differential screening of genomic libraries with total genomic dna preparations. in the current work, a rational design strategy is presented for the development of oligonucleotide probes based upon repeated sequence families. a repeated sequence family present in the genome of onchocerca parasites, designated o-150, has been ... | 1993 | 8479450 |
| use of geographic information systems in control programs for onchocerciasis in guatemala. | 1993 | 8490677 | |
| ultrastructural observations on the nervous system and the sensory organs of the infective stage (l3) of onchocerca volvulus (nematoda: filarioidea). | a detailed morphological investigation of the sensory organs and the nervous system of the third juvenile stage of onchocerca volvulus was performed at the ultrastructural level. a complex system of different receptor cells is found at the anterior and posterior end of this developmental stage. the eight papillae are arranged in two concentric circles consisting of two types of morphologically different receptors. accessory nerve processes end free in the tip of the head. the paired amphids cont ... | 1993 | 8493245 |
| a probable case of vertical transmission of onchocerca volvulus microfilariae. | a probable case of vertical transmission of onchocerca volvulus microfilariae in dass bauchi state, nigeria is presented. a 28-week-old male child delivered by a 39-year-old fulani woman suffering from onchocerciasis was positive for o. volvulus microfilariae based on skin snip examinations. the child had general body pruritic rash and intermittent fever. although the child's skin snip on re-examination five weeks later was also positive, the fever had gradually subsided. | 1993 | 8509623 |
| effect of ivermectin treatment on microfilarial load in patients with onchocerca volvulus in bebeka, ethiopia. | in april 1990, one hundred ninety people from bebeka coffee plantation, kefa administrative region, western ethiopia, all with moderate to heavy infection with onchocerca volvulus were treated with ivermectin (150 mcg/kg body wt.). clinical examination and microfilarial counts in skin snips were repeated at intervals for eight months. therapy was associated with minimal side effects. significant difference in mean microfilarial load was observed throughout the eight months post-treatment period. ... | 1993 | 8513779 |
| pcr mediated cdna synthesis from minute amounts of filarial l3 rna. | 1993 | 8516637 | |
| concurrent parasitic infections in onchocerciasis and the occurrence of adverse reactions after ivermectin treatment. | ivermectin is a safe, effective, and relatively well-tolerated drug for the treatment of human onchocerciasis. however, due to side effects of the drug, large-scale ivermectin distribution without medical supervision is not recommended. the mechanisms involved in the pathogenesis of ivermectin-induced adverse reactions are not yet known. since onchocerciasis patients are likely to have concurrent parasitic infections, we investigated whether side effects that occur after ivermectin treatment cou ... | 1993 | 8517484 |
| a putative protein related to human chemokines encoded antisense to the cdna of an onchocerca volvulus antigen. | chronic hyperactive dermatitis (sowda) in humans infected with the filarial parasite onchocerca volvulus appears to reflect a hyperresponsiveness to parasite antigens. to identify antigens which play a role in this hyperresponsiveness an expression cdna library of adult o. volvulus was screened with sera from patients with sowda. one further characterized cdna clone, s1, consisting of 723 bp, surprisingly shows open reading frames (orf) in both orientations. while a single orf of 171 amino acids ... | 1995 | 8525284 |
| the chemotherapy of onchocerciasis. xix: the clinical and laboratory tolerance of high dose ivermectin. | ivermectin is the drug of choice for the treatment of onchocerciasis. however at the recommended dose of 150 micrograms/kg, it neither kills nor permanently sterilises the adult worms. we investigated whether high doses given with and without a preceding 150 micrograms/kg 'clearing' dose would be tolerable as well as effective against the adult worms. seventy-five healthy males with moderate to heavy infections with onchocerca volvulus were enrolled in a double-blind trial to receive one of the ... | 1995 | 8525285 |
| transglutaminase-catalyzed reaction is important for molting of onchocerca volvulus third-stage larvae. | highly insoluble proteins, which are probably cross-linked, are common in the cuticle and epicuticle of filarial parasites and other nematode species. we have investigated the possible involvement of transglutaminase (tgase)-catalyzed reactions in the development of onchocerca volvulus fourth-stage larvae (l4) by testing the effects of tgase inhibitors on the survival of third-stage larvae (l3) and the molting of l3 to l4 in vitro. the larvae were cultured in the presence of three specific tgase ... | 1995 | 8540691 |
| onchocerca volvulus: identification and characterization of an immunogenic eggshell protein (oveg1). | a major antigen recognized by human sera in onchocerca volvulus infections is a parasite eggshell protein. the cdna clone for this antigen was isolated from a lambda gt11 o. volvulus cdna library using antisera from patients with high microfilarial counts. sequence analysis of the cdna clone predicts a polyglutamine repeat near the 5' end of the cdna, and a motif of four arginines near the 3' end, reminiscent of that found in many regulatory proteins. the cdna was subcloned into a yeast expressi ... | 1995 | 8542985 |
| molecular cloning and characterization of the filarial lim domain proteins avl3-1 and ovl3-1. | a full-length cdna of the filarial nematode acanthocheilonema viteae was isolated from a cdna library of female worms, using a partial cdna of the ovl3-1 gene of onchocerca volvulus as a probe. the avl3-1 cdna contained an open reading frame which encoded for a protein with a theoretical molecular weight of 64 kda. the deduced protein contained a predicted signal sequence, a short repetitive motive of unknown function, and three lim domains. the structure of the lim domains was identical to thos ... | 1995 | 8543001 |
| effect of ivermectin prophylaxis on antibody responses to onchocerca volvulus recombinant antigens in experimentally infected chimpanzees. | antibody responses to recombinant onchocerca volvulus antigens were studied in experimentally infected chimpanzees. sera from 3 groups of 6 animals were tested by elisa with recombinant antigens oc 3.6 and oc 9.3. groups i and ii were treated with 200 micrograms/kg of ivermectin on the day of infection or on day 28, respectively. group iii were untreated controls. antibodies to oc 3.6 developed during the prepatent period in all 3 groups. in contrast, antibodies to oc 9.3 were usually first dete ... | 1995 | 8550298 |
| isotype-specific characterization of antibody responses to onchocerca volvulus in putatively immune individuals. | isotype/subclass-specific antibody responses to adult onchocerca volvulus extract (ovag) were assessed by both elisa and immunoblotting for a group of putatively immune individuals (pis, n = 29) from a hyperendemic area in ecuador and for a group of infected individuals (infs, n = 470) from the same regions. as a group, the pis have been previously shown to possess lower levels of ovag specific igg1, igg2, igg3 and igg4 than inf's but semi-quantitative analysis revealed that the relative proport ... | 1995 | 8552410 |
| mitochondrial alleles of simulium damnosum sensu lato infected with onchocerca volvulus. | onchocerca volvulus infected simulium damnosum s.l. were analysed by directed heteroduplex analysis. of 73 infected flies, 68 produced heteroduplex products identical to those previously identified. all 6 major sibling species, except s. leonense, were present in this group. in the 5 remaining flies, 2 new heteroduplex patterns were noted. molecular phylogenetic analysis of these samples suggested that they belonged to the s. squamosum/s. yahense subcomplex. the ability to reliably genotype adul ... | 1995 | 8557473 |
| low level ivermectin coverage and the transmission of onchocerciasis. | regular collections of biting simulium damnosum s.l. were carried out during a community-based trial of doses of ivermectin every 6 months for onchocerciasis in sierra leone. over 64,000 blackflies were caught at 4 sites close to treated villages and one site near an untreated village. more than 17,000 of these blackflies were dissected during the 31 months of the study and 5 doses of ivermectin were distributed to about 30% of the human population in the treated villages. high annual biting rat ... | 1995 | 8560534 |
| stage-specific and species cross-reactive antibody responses in experimental onchocerca infections of cattle. | cattle experimentally infected with onchocerca lienalis were examined by enzyme-linked immunosorbent assay and immunoblotting to determine the degree of stage- and species-specificity in the immune response to infection. levels of serum antibodies to antigens derived from third-stage larvae increased little after the first three weeks of infection, and the range of antibody specificities remained limited following the appearance of microfilariae (mf) in the skin. in contrast, antibodies to antig ... | 1995 | 8561265 |
| ivermectin-induced immunopotentiation in onchocerciasis: recognition of selected antigens following a single dose of ivermectin. | onchocerciasis is associated with blindness and gross skin changes, believed to be a consequence of the immune response to antigens released from the offspring of the female worm of onchocerca volvulus, the microfilariae (mf). an effective microfilaricidal drug is now available which quickly reduces the mf burden without affecting the adult worm. there exist foci in onchocerciasis endemic areas where some of the patients have many mf in their skin but relatively few clinical symptoms. this state ... | 1996 | 8565307 |
| prevalence of mansonella perstans in western uganda and its detection using the qbc-fluorescence method. | the prevalence of the apathogenic filaria mansonella perstans was studied in four parishes in western uganda as part of an onchocerciasis control programme to avoid futile treatment. blood samples from 1543 persons aged over 14 years from 19 villages were examined for the presence of microfilariae using a modified knott method. the prevalence of microfilaraemic persons ranged between the parishes from 39% (95% ci 35.9-42.0%) to 81% (95% ci 76.2-84.8%). with exception of single microfilariae of o ... | 1996 | 8574245 |
| molecular cloning, expression, and localization of e1, an onchocerca volvulus antigen with similarity to brain ankyrin. | protective immunity against human onchocerciasis may best be reflected by the existence of individuals who in spite of exposure to the filarial nematode onchocerca volvulus do not develop disease (putatively immune). we observed preferential recognition of an o. volvulus antigen of approximately 90 kda by sera from putatively immune individuals compared with sera from diseased individuals. screening of an adult worm cdna library with one serum recognizing this antigen almost exclusively led to t ... | 1996 | 8576165 |
| molecular characterization of a brugia malayi intermediate filament protein which is an excretory-secretory product of adult worms. | filarial parasites release macromolecules into their environment both in vitro and in vivo. these excretory-secretory products (e-s) have been studied with respect to function, vaccination potential, pathogenicity, and ability to serve as antigen targets for diagnostic tests. we have recently described monoclonal antibody ov-1 which binds to an intermediate filament in e-s and circulating antigens of onchocerca volvulus. ov-1 also binds to cross-reactive antigens of brugia malayi. therefore, ov- ... | 1995 | 8577331 |
| autoimmunity and onchocerciasis. | 1996 | 8598734 | |
| absence of cellular responses to a putative autoantigen in onchocercal chorioretinopathy. cellular autoimmunity in onchocercal chorioretinopathy. | onchocerciasis is a major cause of blindness in the developing world. an autoimmune pathogenesis for onchocercal chorioretinopathy was proposed after the identification of a recombinant onchocerca volvulus antigen (designated ov39) demonstrated immunologic crossreactivity with a component of the retinal pigment epithelium and other ocular tissues. the aim of this study was to determine whether patients with onchocercal chorioretinopathy have enhanced lymphoproliferative responses to ov39 compare ... | 1996 | 8603846 |
| parasitic infection of the penis. | 1996 | 8618320 | |
| host-parasite interaction in human onchocerciasis: identification and sequence analysis of a novel human calgranulin. | a novel s100 ca2+-binding protein, termed calgranulin-related protein (cgrp), was purified to homogeneity from extracts of adult onchocerca volvulus, a human tissue-dwelling parasite. its complete amino acid sequence was determined using microanalytical techniques. the primary structure of cgrp consists of 91 residues and displays identity with the recently reported partial sequence of an s100 protein present in human neutrophils. the human origin of cgrp is supported by the occurrence in o. vol ... | 1996 | 8619876 |
| polymerase chain reaction-based assessment after macrofilaricidal therapy in onchocerca volvulus infection. | a recently developed polymerase chain reaction (pcr)-based assay is significantly more sensitive than current methods for diagnosing onchocerca volvulus infection, and it overcomes many difficulties in identifying active onchocerciasis. since chemotherapy is widely used to treat onchocerciasis, the utility of pcr in assessing responses to treatment and in predicting recrudescence is important. twenty-eight patients who had skin snips positive for microfilariae (mf) were studied 120 days after re ... | 1996 | 8627052 |
| identification of onchocerca volvulus collagen as an antigen mainly recognized by antibodies in chronic hyper-reactive onchodermatitis (sowda). | an onchocerca volvulus expression library was differentially screened to identify a molecular marker distinguishing sowda (lichenified onchodermatitis) from other onchocerciasis forms. one clone, pg3, was recognized by pooled sera from patients with sowda, but not by pooled sera from patients with generalized onchocerciasis; it was not recognized by sera from patients with lymphatic filariasis or other helminth infections. the dna of pg3 hybridized strongly with o. volvulus eco ri-digested dna, ... | 1996 | 8644904 |
| in vitro cultivation and development of onchocerca volvulus and onchocerca lienalis microfilariae. | onchocerca volvulus and o. lienalis skin-derived microfilariae (mf) were cultured in vitro; parasite viability was assessed at intervals by measuring their ability to develop in simulium ornatum. in the presence of monkey kidney feeder cells, both species retained full viability when cultured for up to 5 hr before intrathoracic injection into simulium. in the absence of feeder cells and in contrast to o. lienalis, o. volvulus mf rapidly lost their viability. in further trials (including feeder c ... | 1996 | 8651365 |
| the nakalanga syndrome in kabarole district, western uganda. | an acquired condition resulting in arrested growth was reported in the 1950s and 1960s from along the nile near jinja in eastern uganda. this became known as nakalanga dwarfism, and an association with onchocerciasis was postulated. after control of onchocerciasis through larvaciding in this area some 30 years ago, no new cases have been noted. we now report this condition from western uganda where its appearance seems to be a relatively recent event. thirty-one persons with short stature, 15 ye ... | 1996 | 8651377 |
| onchocerca volvulus: development of a species specific polymerase chain reaction-based assay. | 1996 | 8654547 | |
| dirofilaria immitis: ultrastructural localization, molecular characterization, and analysis of the expression of p27, a small heat shock protein homolog of nematodes. | a cdna fragment encoding the complete coding region of a 27-kda protein (p27) of dirofilaria immitis was cloned. antibody to the recombinant p27 bound to hypodermal tissues of third (l3) and fourth stage larvae (l4) of d. immitis and to both the hypodermis and the cuticle of l3s of onchocerca volvulus, as visualized by immunoelectronmicroscopy. the deduced amino acid sequence of the central and c-terminal regions of p27 (amino acids s83 to h222) is 18-36% identical to members of the shsp/alpha-c ... | 1996 | 8654549 |
| a zinc finger gene from onchocerca volvulus encodes a protein with a functional signal peptide and an unusual ser-his finger motif. | the filarial parasite onchocerca volvulus is the causative agent of river blindness. in order to identify genes potentially involved in parasite development we cloned a zinc finger-encoding gene from this species. the ovzf-1 gene represents one member of a family of related zinc finger genes. the predicted ovzf-1 translation product of 447 amino acids includes a hydrophobic signal peptide, which is followed by 13 contiguous finger motifs. the domains of fingers ii-xiii display several conserved ... | 1996 | 8663215 |
| filariasis in the kaiyamba chiefdom, moyamba district sierra leone: an epidemiological and clinical study. | in a cross-sectional epidemiological and clinical study of human filariasis, 630 individuals were examined for onchocerca volvulus, wuchereria bancrofti and mansonella perstans infections in five communities in the kaiyamba chiefdom, moyamba district, sierra leone. the overall prevalence of o. volvulus infection in males 144(39.1%) and females 94(35.9%) was not significantly different and the sex prevalence rate between communities was also not significant (g = 3, d.f. = 4, p > 0.05). prevalence ... | 1996 | 8668763 |
| immunoglobulin kappa chain allotypes (km) in onchocerciasis. | gm and km allotypes, powerful tools for genetic characterization of human populations, have been shown to play an important role in genetic predisposition to some infectious diseases. two diverse racial groups--afro-ecuadorians and amerindians--living in a single restricted geographical area of ecuador, appear to have different risk factors for acquisition and clinical expression of onchocerciasis, a disease caused by the filarial parasite onchocerca volvulus. in this study, gm and km allotypes ... | 1995 | 8675641 |
| human onchocerciasis in nigeria: isotypic responses and antigen recognition in individuals with defined cutaneous pathology. | antigen (ag)-specific isotype responses to onchocerca volvulus ag (ovag) were assessed by enzyme-linked immunosorbent assay and immunoblot in 123 residents of a mesoendemic area in northern nigeria and 16 nigerians from a nonendemic area. individuals from an endemic area were divided into six groups on the basis of cutaneous onchocercal pathology: acute papular onchodermatitis (apod), chronic papular onchodermatitis (cpod), lichenified onchodermatitis (lod), atrophy (atr), depigmentation (dpm) a ... | 1996 | 8686779 |
| integrated control of onchocerca volvulus infection in a hyperendemic zone in sierra leone. | a simplified integrated method of onchocerciasis control involving mass chemotherapy with ivermectin, nodulectomy and health education was carried out in south central sierra leone. the prevalence of onchocerca volvulus in the village community ranged from a low of 7.4% among the international school children to a high of 97.0% in gbessebu. there was a significant (3-4%) overall reduction in the rate of infection after one year of ivermectin treatment (g = 2565.97, df = 11, p < 0.001). in additi ... | 1996 | 8698012 |
| immunoregulation in onchocerciasis: persons with ocular inflammatory disease produce a th2-like response to onchocerca volvulus antigen. | to examine the role of specific cytokines in mediating the clinical manifestations of human onchocercal disease, microfilariae-positive ghanaian subjects with inflammatory ocular disease were compared with microfilariae-positive subjects without ocular disease. onchocerca volvulus antigen (ovag)-stimulated peripheral blood mononuclear cells (pbmc) from subjects with disease produced significantly more interleukin (il)-10 (with disease = 447.34 vs. without disease = 292.22 pg/ml; p < .01) and il- ... | 1996 | 8699070 |
| actin gene structure in two artemia species, a. franciscana and a. parthenogenetica. | genomic clones coding for actin have been isolated from two species of the crustacean artemia, a. parthenogenetica and a. franciscana. the act211 isoform gene was isolated from a. parthenogenetica, and the two other isoform genes, act302 and act403, were isolated from a. franciscana. the comparison of the nucleotide sequence of genomic and cdna clones showed an interspecific divergence of 4% in translated and 6.1% in untranslated regions. however, the establishment of the partial structure of th ... | 1996 | 8703088 |
| onchocerciasis in ecuador: evolution of chorioretinopathy after amocarzine treatment. | to investigate the impact of the macrofilaricidal drug, amocarzine, on the evolution of chorioretinopathy in onchocerciasis. | 1996 | 8703886 |
| cdnas from onchocerca sp. encoding members of the mrs3/mrs4 class of mitochondrial solute carriers. | cdna clones from the parasitic nematodes onchocerca volvulus and onchocerca gibsoni encode homologs of the yeast proteins mrs3 and mrs4. together with an uncharacterised orf on chromosome iii of caenorhabditis elegans, these constitute a new class of proteins belonging to the mitochondrial solute carrier protein superfamily. so far, five other members of this protein family have been identified in c. elegans, but levels of identity between these and the onchocerca proteins were considerably lowe ... | 1996 | 8703971 |
| immunoregulation in onchocerciasis: predominance of th1-type responsiveness to low molecular weight antigens of onchocerca volvulus in exposed individuals without microfilaridermia and clinical disease. | chronic and generalized onchocerciasis is associated with suppression of the parasite-specific cellular responsiveness, while exposed individuals without parasitological and clinical evidence of infection (endemic normals) display prominent cellular reactivity to onchocerca volvulus antigens (ovag). in order to identify those parasite antigens which may account for this differential cellular responsiveness, total adult worm-derived ovag were fractionated by means of preparative sds-page and blot ... | 1996 | 8706329 |
| the putatively protective onchocerca volvulus neuronal protein e1 is a member of the death domain protein family. | here we show that e1, an ankyrin-related, potentially protective, neuronal protein of the human filarial nematode onchocerca volvulus contains a death domain (dd), most similar to that of human mort1/fadd (39% identity). in addition, sequence comparison of e1 to its homologue from litomosoides sigmodontis and to caenorhabditis elegans ankyrin defines two further putative functional domains. one represents the end of the spectrin-binding domain of ankyrins, the other an unique domain, most highly ... | 1996 | 8706821 |
| the ultrastructure of the anterior end of male onchocerca volvulus: papillae, amphids, nerve ring and first indication of an excretory system in the adult filarial worm. | a detailed morphological investigation of the anterior sensory organs, the nerve ring and a glomerulus-like structure in male onchocerca volvulus was performed by means of electron microscopy. the 8 head papillae are arranged in the common 4 + 4 pattern of most filarial worms in circles around the mouth opening. the amphidial openings are found between the circles of inner and outer papillae on both sides of the mouth. inside, several additional nerve axons are seen in the tissue of the anterior ... | 1996 | 8710418 |
| cloning and expression of dit33 from dirofilaria immitis: a specific and early marker of heartworm infection. | dirofilaria immitis is an important filarial parasite of dogs and cats, and a useful model for human filariasis. current diagnostic tests for heartworm infection in animals rely on the presence of fecund female worms (usually found 6.5 months post-infection or later) and therefore fail to detect pre-patent infections. putative pepsin inhibitors from 2 filarial parasites of humans namely onchocerca volvulus (ov33, oc3.6, ovd5b) and brugia malayi (bm33), have been shown to be useful in diagnosis o ... | 1996 | 8728997 |
| impaired antibody responses and loss of reactivity to onchocerca volvulus antigens by hiv-seropositive onchocerciasis patients. | the impact of concomitant human immunodeficiency virus (hiv) infection on the antibody response of onchocerciasis patients to onchocerca volvulus antigens (ovag) was studied by western blotting and enzyme linked immunosorbent assay (elisa). immunoglobulin g (igg) antibodies in sera from 45 hiv-sero-positive o. volvulus microfilariae (mf) carriers (hiv+/ov+) recognized significantly fewer distinct o. volvulus antigenic bands, and responded less frequently to all detected bands compared to sera fr ... | 1996 | 8730320 |
| onchocerciasis in ecuador: changes in prevalence of ocular lesions in onchocerca volvulus infected individuals over the period 1980-1990. | trends in prevalence rates of onchocercal ocular lesions were examined over the period 1980 to 1990 using data from two cross-sectional surveys. there was evidence for increasing prevalence of anterior chamber microfilariae, iridocyclitis, optic atrophy, and chorioretinopathy. large increases in prevalence, in particular, were seen for posterior segment lesions: optic atrophy increased from 2.7% to 6.4% and chorioretinopathy from 8.8% to 35.6%. greatest increases in these lesions were seen in th ... | 1996 | 8736083 |
| sensitivity of a polymerase chain reaction-based assay to detect onchocerca volvulus dna in skin biopsies. | a polymerase chain reaction (pcr) of a 150-bp tandem repeat of onchocerca volvulus (o-150) combined with southern-blot hybridization to species-specific dna probes was employed for dna detection. o-150 was amplified from parasites originating from uganda, benin, cameroon, liberia, ghana, burkina faso, mali, and zaire and was successfully hybridized to digoxigenin-labeled oligonucleotides. to investigate the sensitivity of the pcr, 2 skin biopsies were taken from each of 227 persons from uganda w ... | 1996 | 8738277 |
| characterization of the arylalkylamine n-acetyltransferase in onchocerca volvulus. | the characteristics and kinetic properties of an arylalkylamine n-acetyltransferase were studied in partially purified preparations of the human filarial parasite onchocerca volvulus. the enzyme, which had a relative molecular mass (m(r)) of 37-38 kda, catalyzed the acetylation of arylalkylamines but did not accept arylamines or polyamines as substrates. the optimal ph for enzyme activity was found to be 8.5 in tris-hci. the apparent michaelis constant (k(m)) and maximum velocity (vmax) determin ... | 1996 | 8740555 |
| resumption of menstruation in three women with secondary amenorrhoea after treatment with ivermectin. | 1995 | 8745946 | |
| the use of degenerate primers in conjunction with strain and species oligonucleotides to classify onchocerca volvulus. | 1996 | 8751366 | |
| absence of cellular responses to a putative autoantigen in onchocercal chorioretinopathy: cellular autoimmunity in onchocercal chorioretinopathy. | 1996 | 8759337 | |
| polymerase chain reaction for detecting onchocerca volvulus in pools of blackflies. | the detection of onchocerca volvulus infected simuliids or blackflies is routinely done by dissection and microscopic examination of individual flies, but this method is tedious and time consuming. here we describe a method of detecting single o. volvulus infected blackflies in pools of uninfected blackflies. using a pcr with onchocerca specific primers it is possible to reproducibly detect one heavily infected blackfly in a pool of 80 flies, or to detect one blackfly inoculated with one microfi ... | 1996 | 8765461 |
| immunoglobulin g subclass responses of children during infection with onchocerca volvulus. | to characterize the patterns of immunoglobulin g (igg) subclass and ige reactivity during the early stages of onchocerciasis, sera were collected from 224 children (age groups, 2 to 5, 6 to 10, and 11 to 15 years) residing in a region of sierra leone where onchocerca volvulus is endemic, and these samples were tested by enzyme-linked immunosorbent assay for their reactivity to adult antigens (ovag) and against four recombinant proteins (ov11, ov27, ov29, and ov16). over 88% of the samples contai ... | 1996 | 8770512 |
| the prevalence of epilepsy follows the distribution of onchocerciasis in a west ugandan focus. | epidemiological surveys indicate that the prevalence of epilepsy is higher in developing countries than in industrialized countries. except for neurocystocercosis due to taenia solium, little is known about possible underlying causes. this article reports the relationship between epilepsy and onchocerciasis in an onchocerca volvulus endemic area in west uganda. individuals complaining of seizures were identified by means of a population census in 12 villages. active epilepsy was confirmed in 61 ... | 1996 | 8823957 |
| dependence of eosinophil granulocyte infiltration into nodules on the presence of microfilariae producing onchocerca volvulus. | onchocercomata with a single live or dead worm were analyzed to elucidate the infiltration of eosinophils. females were classified according to the presence or absence of microfilariae in their uteri and in the nodular tissues. immunohistochemical staining was performed using antibodies against eosinophil cationic protein, peroxidase, and major basic protein. very few eosinophils were detected in nodules containing females without microfilariae or male or dead worms only, whereas eosinophils wer ... | 1996 | 8825205 |
| ivermectin treatment of hyperreactive onchodermatitis (sowda) in liberia. | seventeen male and 39 female liberian patients, one third of them children, were diagnosed as having hyperreactive onchodermatitis (sowda). they presented with itching (98%), asymmetric (98%), chronic onchodermatitis (median 5 years), and swelling of femoral lymph nodes (89%). the geometric means of the microfilaria (mf) densities were 1.0 mf/mg in children and 0.7 mf/mg in adults. these patients not only suffered from their skin lesions, and severe itching resulting in disturbance of sleep but ... | 1995 | 8826099 |
| the chemotherapy of onchocerciasis xx: ivermectin in combination with albendazole. | ivermectin is a potent microfilaricide that also blocks microfilarial release while albendazole is toxic to all intrauterine stages. we investigated whether their combination would permanently sterilize the adult worms. in the first open phase, all 69 patients received 150 micrograms/kg of ivermectin. in the second double-blind phase one week later, 35 patients were randomized to receive 800 mg of albendazole with a fatty breakfast for three consecutive days while 34 patients received matching p ... | 1995 | 8826100 |
| anthropophilic blackflies (diptera: simuliidae) and onchocerciasis transmission in southwest ethiopia. | from may 1984 to may 1985, the transmission of onchocerciasis by blackflies (dipteria: simuliidae) was studied around gilgel ghibe and gojeb rivers in southwest ethiopia. the predominant anthropophilic species of simulium at both localities were s. (edwardsellum) damnosum sensu lato and s. (lewisellum) ethiopiense. some s. (anasolen) dentulosum also landed on human bait at gilgel ghibe river. dissections of s. damnosum from gilgel ghibe and gojeb revealed mean parous rates of 92% (n = 18,291) an ... | 1996 | 8834742 |
| ivermectin distribution in the plasma and tissues of patients infected with onchocerca volvulus. | to determine the distribution of ivermectin in plasma and tissues of onchocerciasis patients following a single oral dose of 150 micrograms kg-1. | 1996 | 8839664 |
| met-11 of hla class ii dp alpha 1 first domain associated with onchocerciasis. | human infection with the pathogenic tissue nematode onchocerca volvulus may result in a spectrum of clinical manifestations or in a putatively immune condition. a methionine at amino acid position 11 of the hla class ii dp alpha 1 chain correlates with the occurring disease after infection (relative risk 3.3). the alternative alanine at position 11 is, conversely, associated with protection from disease ("relative protection' 3.5). dpa1*0301 is associated with the localized form of disease after ... | 1996 | 8854084 |
| a cyclosporin a-sensitive small molecular weight cyclophilin of filarial parasites. | 1996 | 8855561 | |
| density-dependent processes in the transmission of human onchocerciasis: relationship between microfilarial intake and mortality of the simuliid vector. | in order to construct an analytical model of onchocerciasis transmission, it is necessary to elucidate the functional relationships of the various population rate processes taking place within the human and vector hosts. two previous papers have explored the evidence for density-dependent regulation in relation to microfilarial intake by, and larval development within, the simulium host. this paper investigates the survivorship of wild-caught blackfly samples fed on subjects with different inten ... | 1996 | 8873475 |
| neutrophil granule proteins: evidence for the participation in the host reaction to skin microfilariae of onchocerca volvulus after diethylcarbamazine administration. | the participation of neutrophil granulocytes in the cellular reaction to skin microfilariae of onchocerca volvulus was studied by immunohistochemistry. skin biopsies were obtained from adult liberian and ugandan patients with generalized onchocerciasis after exposure to topically applied diethylcarbamazine (dec) and from untreated patients. after dec many damaged microfilariae were observed either in dermal infiltrates or in epidermal microabscesses consisting both of neutrophils and eosinophils ... | 1996 | 8873478 |