| [problems in the investigation of the control of onchocerca volvulus in mexico]. | the treatment and control of onchocerciasis in mexico has been supported only on the administration of diethylcarbamazine and the removal of adult worms, which are in the onchocercomata. these actions seems to have diminished the prevalence and incidence of blindness in those individuals who are affected by this parasitosis. however, there has not been an important impact on onchocerciasis transmission. the objective of this paper is to critically analyze and discuss subjects related to diagnosi ... | 1991 | 1948427 |
| experimental infection of humans with filariae. | this report summarizes the findings of the 17 published studies involving humans who have been experimentally infected with filarial parasites. over the past 60 years, 45 individuals have been deliberately infected with wuchereria bancrofti, brugia malayi, brugia pahangi, loa loa, mansonella perstans, mansonella ozzardi, and/or onchocerca volvulus. the findings from these experimental infections of humans have helped define microfilarial survival and periodicity within human hosts, the prepatent ... | 1991 | 1962076 |
| ocular onchocerciasis and intensity of infection in the community. iii. west african rainforest foci of the vector simulium sanctipauli. | the community pattern of ocular onchocerciasis is described for 11 villages from the forest area in côte d'ivoire where s. sanctipauli is the princial vector. an analytical method is applied which relates indices of ocular onchocerciasis with the community microfilarial load (cmfl) and compares the results with the ocular onchocerciasis pattern found in the west african savanna. in spite of high transmission levels as estimated by entomological indices, the cmfls were relatively low which compli ... | 1990 | 1963702 |
| safety of and compliance with community-based ivermectin therapy. | in a study of the safety, acceptability, and efficacy of ivermectin for community-based mass treatment of onchocerciasis, the drug was issued twice, one year apart, to the population of a rubber plantation (14,000 people) in liberia, where over 80% of the adults have onchocerca volvulus infection. the plantation microfilarial load in a sample of adults was reduced by 86% 6 months after initial treatment and by 78% after 1 year. compliance was 97% with each round of treatment. after the initial t ... | 1990 | 1971669 |
| identification of different radiolabelled antigens of the developmental stages of onchocerca volvulus. | by using radioiodination methods which are thought to label preferentially the surface followed by sds-page and autoradiography, components of different developmental stages of o. volvulus have been identified. between 2 and 10 polypeptide antigens were revealed on infective larvae (l3), females, males, eggs, nodular and skin microfilariae by using immunoblotting assays with human onchocerciasis sera. antigen recognition did not vary with the density of skin microfilariae in the patients from wh ... | 1990 | 1978531 |
| antibodies against the cuticlin of ascaris suum cross-react with epicuticular structures of filarial parasites. | the insoluble cuticlin from the cortical zone of the cuticle of adult ascaris suum was purified and used to raise antibodies in c57/bl mice. the specificity of the antibodies for the external cortical layer was shown in the indirect immunofluorescence antibody test and by immunoelectronmicroscopy. a very high specificity for the external cortical layer was found. some cross-reactions with cuticular collagens occurred, and increased after booster immunizations. the anti-cuticlin antibody cross-re ... | 1990 | 1978533 |
| ultrastructural study of the interaction between eosinophilic granulocytes and third and fourth stage larvae of onchocerca volvulus. | the interaction in vitro between eosinophil effector cells and third and fourth stage larvae of onchocerca volvulus was studied by electron microscopy. the morphological observations demonstrated different mechanisms of attack of eosinophil cells that are dependent upon the time of incubation. rapid adherence to the cuticle of the target, flattening, secretion of granule contents, vacuole formation and, finally, complete degranulation of the eosinophils were seen after incubation with third stag ... | 1990 | 1980799 |
| a comparison of 6-, 12-, and 24-monthly dosing with ivermectin for treatment of onchocerciasis. | this study was designed to examine the optimal dose and interval of administration of ivermectin, the now-accepted drug of choice for onchocerciasis. two hundred liberians with onchocerca volvulus infection received 100, 150, or 200 micrograms/kg ivermectin or placebo and were followed for 36 months. the reaction after the second dose of ivermectin was significantly less than after the initial dose, although it was still significant in the 200-micrograms/kg group. the skin microfilaria counts in ... | 1991 | 1988521 |
| community-based treatment of onchocerciasis with ivermectin: safety, efficacy, and acceptability of yearly treatment. | the safety, acceptability, and efficacy of ivermectin during community-based mass treatment of onchocerciasis was assessed. ivermectin was distributed three times, 1 year apart, to the population of a rubber plantation (14,000 people) in liberia where greater than 80% of adults have onchocerca volvulus infection. in a sample of adults, the microfilarial density was reduced by 84% after 2 years of treatment. acceptance was as high as 98% during the third year. adverse reactions occurred in 6-13 i ... | 1991 | 1988522 |
| onchocerca volvulus, o. gutturosa, brugia malayi, and dirofilaria immitis: a comparative study of the immunochemical properties of cuticular proteins from filarial parasites. | we compared the chemical and immunological properties of cuticular collagens from four species of filarial nematodes, onchocerca volvulus, o. gutturosa, brugia malayi, and dirofilaria immitis. the electrophoretic mobility of the major polypeptides extracted from adult worms is characteristic for each species studied. cuticular collagens from adult worms and infective larvae differ in their susceptibility to proteases that cleave vertebrate collagens and to collagenases prepared from different de ... | 1991 | 2009921 |
| an immunogenic onchocerca volvulus antigen: a specific and early marker of infection. | onchocerciasis (river blindness) is a serious health problem and a severe obstacle to social and economic development, especially in africa. a complementary dna fragment coding for an onchocerca volvulus antigen (ov-16) was cloned and expressed in the plasmid vector pcg808fx. immune responses to this o. volvulus-specific recombinant antigen were detectable in patients with documented onchocerciasis; the antibody response was also detectable at 3 months and at more than 1 year before infection co ... | 1991 | 2011741 |
| experimental onchocerca volvulus infections in mangabey monkeys (cercocebus atys) compared to infections in humans and chimpanzees (pan troglodytes). | three chimpanzees, three mangabey monkeys (cercocebus atys), and 14 patas monkeys (erythrocebus patas) were inoculated with l3 onchocerca volvulus of guatemalan origin. one chimpanzee and two mangabey monkeys developed antibody activity to at least three different antigens. both mangabey monkeys recognized a 20 kda antigen 3.5-5 months post-inoculation, and the monkeys and the chimpanzee developed antibody activity to 14 and 22 kda antigens 7.5-13 months post-inoculation. one mangabey monkey and ... | 1991 | 2012258 |
| eosinophil-larval-interaction in onchocerciasis: heterogeneity of in vitro adherence of eosinophils to infective third and fourth stage larvae and microfilariae of onchocerca volvulus. | adherence of eosinophilic granulocytes from patients with onchocerciasis to microfilariae (mf), third (l3) and fourth (l4) stage larvae of onchocerca volvulus was studied in vitro. native and heat-inactivated sera from patients with onchocerciasis (os), from endemic controls without signs of the disease (ecs), from healthy caucasians (ns) or foetal calf serum (fcs) served as sources for adherence mediating factors. in fcs-supplemented medium eosinophils did not adhere to any larvae. none of the ... | 1991 | 2014134 |
| experimental ocular onchocerciasis in cynomolgus monkeys. iv. chorioretinitis elicited by onchocerca volvulus microfilariae. | onchocerciasis is a major cause of blindness worldwide, and much of the blindness is caused by onchocercal chorioretinitis. in an experimental animal model for ocular onchocerciasis, intravitreal injections of 10,000 live onchocerca volvulus microfilariae isolated from infected humans into the eyes of cynomolgus monkeys (macaca fascicularis) resulted in patchy, progressive loss of retinal pigment with pigment clumping. areas of pigment loss were less extensive in animals that had been sensitized ... | 1991 | 2016131 |
| 2-acetylpyridine thiosemicarbazones. 13. derivatives with antifilarial activity. | several members of a series of 2-acetylpyridine thiosemicarbazones possess in vivo and in vitro macrofilaricidal properties. the most promising of the group tested is n4-(2-aminophenyl)-2-[1-(2-pyridinyl)ethylidene]-hydrazinecarbothioam ide (4), which suppressed 100% of the macrofilariae of brugia pahangi and 94% of those of acanthocheilonema viteae in the jird at a dose of 25 mg/kg per day x 5. compounds 4 and 14 were also shown to inactivate or kill onchocerca gutturosa and onchocerca volvulus ... | 1991 | 2016717 |
| immunity to onchocerciasis: recognition of larval antigens by humans putatively immune to onchocerca volvulus infection. | immunoblot analyses were done using sera from 12 individuals without evidence of onchocerciasis and 16 with active infection from an area of guatemala holoendemic for onchocerciasis. for adult antigens from onchocerca volvulus, no differences in antigen recognition could be identified between the two groups. in contrast, when infective larval (l3) antigen preparations derived from the related animal parasite onchocerca lienalis were used, igg from the "immune" individuals preferentially recogniz ... | 1991 | 2019761 |
| improvement in severe onchocercal skin disease after a single dose of ivermectin. | skin disease is the most common clinically important manifestation of onchocerciasis. ivermectin, a newly available drug, is well tolerated and effective in onchocerca volvulus infection. however, little information is available regarding its effect on onchocercal skin disease. the purpose of this study was to examine, in patients with well-characterized onchodermatitis, the effect of a single dose of ivermectin. | 1991 | 2029016 |
| guatemalan human onchocerciasis. i. systematic analysis of patient populations, nodular antigens, and specific isotypic reactions. | the population from five guatemalan plantations in areas endemic for onchocerciasis was surveyed, and 1032 individuals were recruited to participate in our study. from physical examination, past clinical history (5 to 8 yr), laboratory evidence and sample availability, a group of 778 long term residents with confirmed disease status were selected for detailed examination. we were able to identify 268 long term residents of endemic areas who had never been infected, 44 of these are from hyper- an ... | 1991 | 2033267 |
| guatemalan human onchocerciasis. ii. evidence for igg3 involvement in acquired immunity to onchocerca volvulus and identification of possible immune-associated antigens. | ag-specific isotypic differences in immune response to onchocerca volvulus ag were assessed for 778 long term residents of endemic guatemalan areas by quantitative elisa with 5-min incubation steps and immunoblot. the study population was separated into five groups based on clinical status: n+f+, n+f-, n-f+, n-f-h+, and n-f-h-, where n = o. volvulus adults (nodule), f = microfiladermia, and h = history of o. volvulus infection. a subset of 44 individuals with high exposure to onchocerciasis from ... | 1991 | 2033268 |
| analysis of aqueous humour in ocular onchocerciasis. | the development of an onchocercal chorioretinopathy from the first detectable signs to a full blown oncho fundus is not fully understood. we investigated the intraocular humoral immune response against onchocerca volvulus, human s-antigen, irbp and crude retinal extract (using an elisa) by examining paired aqueous humour and serum samples obtained from onchocerciasis patients (without [n = 10] and with ocular symptoms [n = 8]) and endemic controls [n = 14] from sierra leone (west africa). a loca ... | 1991 | 2036808 |
| characterization and molecular cloning of a cu/zn superoxide dismutase from the human parasite onchocerca volvulus. | evidence suggests that the helminth antioxidant enzyme superoxide dismutase (sod) may play a role in parasite's defense against the cellular immune mechanisms of the host. in order to investigate this for the human parasite onchocerca volvulus, the enzyme activity was characterized, the release of sod by the parasite was examined, and a complete cdna encoding the o. volvulus sod was identified. the sod activity in adult o. volvulus was found to be 8.1 +/- 4.2 u/mg of protein. a cu/zn-containing ... | 1991 | 2037366 |
| surface antigens of male worms and microfilariae of onchocerca gibsoni. | living adult males and microfilariae of the cattle filarial parasite onchocerca gibsoni were externally labelled with radioactive iodine using the iodogen and bolton-hunter procedures. characterization of labelled surface proteins by sodium dodecyl sulphate (sds)-polyacrylamide gel electrophoresis revealed clear cut differences in the two life cycle stages. in addition, the two radiolabelling procedures yielded some differences in the profiles of radiolabelled surface proteins for both adults an ... | 1991 | 2040568 |
| experimental onchocerciasis in chimpanzees. cell-mediated immune responses, and production and effects of il-1 and il-2 with onchocerca volvulus infection. | nine of eighteen chimpanzees inoculated with infective third-stage larvae of onchocerca volvulus developed patent infection with microfilariae in skin biopsies. in all infected chimpanzees the in vitro cellular reactivity to o. volvulus adult worm-derived ag (ovag) increased significantly after exposure to third-stage larvae. however, during prepatency the in vitro cellular responses to ovag decreased gradually in subsequently mf positive (patent) animals, and returned with patency to values not ... | 1991 | 2051025 |
| characterization of an onchocerca volvulus cdna clone encoding a genus specific antigen present in infective larvae and adult worms. | the isolation and characterization of a recombinant cdna clone (ov7) expressing an antigen present in onchocerca volvulus infective larvae and adult stages is described. using chimpanzee antiserum generated against irradiated infective larvae, we isolated a cdna clone from a lambda gt11 cdna expression library derived from adult o. volvulus mrna. the open reading frame encodes 131 amino acids corresponding to a 15.2-kda protein. affinity purified antibodies which bound specifically to ov7 fusion ... | 1991 | 2052041 |
| migration and death of skin-dwelling onchocerca volvulus microfilariae after treatment with ivermectin. | the effects of a single dose of ivermectin (122-200 micrograms/kg) on onchocerca volvulus microfilariae (mf) in skin and lymph nodes were studied histologically in a qualitative and quantitative manner over seven days after treatment. ivermectin caused mf to move from the subepidermal layer into the deeper layers of the dermis, subcutaneous fat and connective tissue, and the regional lymph nodes. no mf were seen migrating upwards through the epidermis. dead mf were not seen before 24 hr and the ... | 1991 | 2052852 |
| immunological crossreactivity between a cloned antigen of onchocerca volvulus and a component of the retinal pigment epithelium. | onchocerciasis (river blindness) is a major blinding disease in africa, central america, and south america. loss of vision can be due to corneal change, optic atrophy, or chorioretinal disease. it has been suggested that autoimmunological reactions resulting from crossreactivity between parasite antigens and components of eye tissues contribute to development of ocular pathology. using sera collected from onchocerciasis patients as a screening reagent, a cdna clone (ov39) has been isolated from ... | 1991 | 2056276 |
| immunological studies on onchocerciasis in sierra leone. 1. pretreatment baseline data. | cellular immune responses were tested in vitro using peripheral blood mononuclear cells from 203 individuals resident in an area of sierra leone where onchocerciasis is hyperendemic, and 32 individuals (gambians) with no history of contact with onchocerca volvulus. mean reactivity to the mitogen, concanavalin a, did not differ between these two groups, but responses to ppd were markedly lower in those with onchocerciasis. proliferative responses to adult female o. volvulus antigen in the latter ... | 1990 | 2075381 |
| the chemotherapy of onchocerciasis. xiv. studies with mebendazole citrate. | twenty patients from an area of vector control in the savannah region of northern ghana with moderate to heavy infection with onchocerca volvulus were randomised to receive two priming doses of levamisole 150 mg on two occasions followed either by mebendazole-citrate (500 mg) given daily or twice daily for 14 days. the two dose levels produced a similar effect on skin microfilariae (80-88% reduction) with a very mild systemic clinical reaction: low levels were maintained over 42 weeks. both regi ... | 1990 | 2075382 |
| on the reproductive activity of the female onchocerca volvulus. | onchocerca volvulus worms, extracted from nodules by collagenase digestion, stained with haematoxylin and cleared in glycerol, were unravelled for longitudinal examination and later embedded in brain blocks for study of serial transverse sections. a classification system for female worms is proposed, based on the reproductive status of 446 worms from guatemala, 94 from liberia and 125 from mali. they were categorized into fecund, inseminated specimens; uninseminated, but potentially fertile spec ... | 1990 | 2075383 |
| morphological alterations of male onchocerca volvulus after in vitro exposure to mel w and milbemycin a confirming the results of viability tests. | the suitability of two viability parameters used for screening of antifilarial activities of new compounds was examined by parallel observation of the morphology. male onchocerca volvulus were exposed in vitro to 10 mumol mel w and milbemycin a and examined by light and transmission electron microscopy. the viability was assessed by measurement of the motility, using a micromotility meter and by determination of tetrazolium reduction. already twelve hours after exposure to mel w the muscles of t ... | 1990 | 2075389 |
| the transmission of onchocerciasis at a forest village in sierra leone. i. simulium damnosum s.l. biting densities and infection with onchocerca volvulus at five representative sites. | previous studies in the forest area of sierra leone have shown that transmission of onchocerca volvulus takes place many kilometers away from large breeding rivers and sometimes in open farmland. to determine where and when people in a forest village were most likely to be infected, catches of simulium damnosum s.l. were carried out every week for 12 months, at five sites in and near a village where onchocerciasis was mesoendemic. the number of flies caught per man a day at open farm sites was s ... | 1990 | 2076037 |
| biometric characteristics of onchocerca volvulus in two neotropical populations. | | 1990 | 2076041 |
| [the correlation between onchocercomas and positivity for microfilaria in onchocerciasis]. | the objective of this work is to evaluate the palpation sensitivity of onchocercomata for the diagnosis of onchocerciasis in individuals residents of the locality of nueva costa rica, mapastepec, in the south endemic area of the state of chiapas, mexico. every one of the 243 individuals who voluntarily participate in this study was interrogated and physical examined for the detection of nodules. the positivity and the worm burden to the onchocerca volvulus infections was estimated by the presenc ... | 1990 | 2089642 |
| specific and cross-reacting antibodies in human responses to onchocerca volvulus and dracunculus medinensis infections. | immunoelectroblotting and enzyme-linked immunosorbent assay were used to identify non-cross-reacting antigenic components of dracunculus medinensis and the filarial worms onchocerca volvulus, loa loa, wuchereria bancrofti, brugia malayi, and mansonella ozzardi. parasite specific serodiagnostic elisa systems for onchocerciasis and dracunculiasis were devised based on these findings. phosphate buffered saline extracts of adult worms were passed through a column of monoclonal antibodies to phosphor ... | 1990 | 2138430 |
| immunodiagnosis of dracunculiasis by falcon assay screening test-enzyme-linked immunosorbent assay (fast-elisa) and by enzyme-linked immunoelectrotransfer blot (eitb) technique. | the falcon assay screening test-enzyme-linked immunosorbent assay (fast-elisa) and the enzyme-linked immunoelectrotransfer blot (eitb) technique were used to test human sera with dracunculus medinensis adult worm antigen in order to assess their potential value in the immunodiagnosis of dracunculiasis. the human sera used were from patients with prepatent and patent d. medinensis infections or from patients infected with other nematodes (onchocerca volvulus and loa loa) or trematodes (schistosom ... | 1990 | 2148463 |
| igg4 subclass antibody serology for onchocerciasis. | antibodies to phosphorylcholine and carbohydrate determinants responsible for much of the cross-reactivity among nematodes are subclass restricted in humans and absent in the igg4 subclass. total igg and igg4 antibody responses to onchocerca volvulus were examined by enzyme immunoassay and by immunoblot. significant background igg reactivity was detected in both assays in us control sera and sera from patients with intestinal nematode infections, but background reactivity was negligible in the i ... | 1990 | 2179425 |
| ivermectin: a long-acting microfilaricidal agent. | ivermectin is a macrocyclic lactone (fermentation) product and actinomycete (streptomyces avermitilis) that possesses an unusually broad spectrum of potent activity against several species of nematodes, arachnids, and insects that parasitize domestic animals. from clinical trials in humans it has been found to be microfilaricidal, killing microfilariae of onchocerca volvulus (the parasite causing onchocerciasis), and interrupting its transmission by the black fly vector. dermal microfilariae den ... | 1990 | 2183496 |
| use of monoclonal antibodies for the characterization of onchocerca volvulus antigens. | in order to identify onchocerca volvulus antigens that could be considered as either diagnostic and/or immunoprophylactic, mouse monoclonal antibodies were produced against o. volvulus soluble antigens. three were selected on the basis of their staining patterns in an indirect fluorescent antibody assay carried out on cryosections of adult o. volvulus. the first monoclonal antibody (k1-159) recognized a cuticular antigen which appeared in ifa to be restricted to the genus onchocerca. however, ne ... | 1990 | 2187226 |
| onchocerciasis. | onchocerciasis is a devastating blinding disease caused by the parasite onchocerca volvulus that infects about 80 million people, causing blindness and visual impairment in 1-2 million people. in hyperendemic areas, more than half of the population will become blind from onchocerciasis before they die. blindness is the most important effect of the disease and results, in part, from direct invasion of the eye by microfilariae. the recent development of ivermectin has revolutionized our ability to ... | 1990 | 2188920 |
| characterization of a myosin-like antigen from onchocerca volvulus. | recombinant cdnas expressing an immunodominant antigen (onchoag-1) of onchocerca volvulus were identified by immunoscreening a cdna expression library. the onchoag-1 cdnas are derived from an 8-kb mrna that codes for a protein with an apparent molecular mass of 200 kda. indirect immunofluorescence using antisera against a recombinant fusion protein showed that onchoag-1 is located in the muscle tissues of adult o. volvulus. the 2-kb sequence of one of the cdnas contains a single open translation ... | 1990 | 2194123 |
| changes in antibody profile after treatment of human onchocerciasis. | to define the changes in antibody response to onchocerca volvulus antigens after treatment of patients with onchocerciasis, igg and ige antibodies were examined quantitatively and qualitatively in 21 patients and 3 control individuals before and sequentially for 14 days after treatment with diethylcarbamazine. the quantitative levels of ige and igg responses (both polyclonal and o. volvulus-specific) remained essentially unchanged for all patients, but 9 of the 21 patients showed intensified res ... | 1990 | 2197344 |
| large scale ivermectin distribution and its epidemiological consequences. | community trials were started to address questions concerning the safety of ivermectin during large scale treatment, its potential for transmission control, its effect in preventing ocular onchocercal disease, its acceptability and the organization of large scale treatment. a summary is presented of the major, latest results on the short-term epidemiological impact of large scale ivermectin treatment, as observed in eight community trials undertaken in the onchocerciasis control programme in wes ... | 1990 | 2198750 |
| ivermectin treatment of ocular onchocerciasis. | ivermectin, a recently developed macrocyclic lactone with broad antiparasitic activity, has been shown by a series of clinical trials to be safe and effective in the treatment of human infection with onchocerca volvulus. although it is rapidly microfilaricidal, it does not cause a severe reaction as is seen with diethylcarbamazine treatment. in patients with onchocerciasis, a single oral dose of ivermectin (150 micrograms/kg) repeated once a year leads to a marked reduction in skin microfilaria ... | 1990 | 2198751 |
| human onchocerciasis--an overview of the disease. | the general characteristics of onchocerca volvulus infection and its transmission are outlined in this overview of human onchocerciasis. the pathogenic role of the microfilariae, producing lesions of the skin, lymphatic system, eye and deep organs, are described, along with the main clinical manifestations of the disease. the global prevalence and distribution of onchocerciasis are given. best estimates in 1985 gave 86 million persons at risk, 17.8 million infected, 336,400 blind and a like numb ... | 1990 | 2198761 |
| an economical procedure for screening of hybridoma supernatants for surface reactive antibodies to filarial larvae. | third- and fourth-stage larvae of onchocerca volvulus can be attached to the lids of 96-well microtiter plates to facilitate the screening of hybridoma supernatants reactive with filarial larvae. plates are coated with a solution consisting of 0.1% gelatin, and 0.01% chrome alum. following coating of plate lids one larva per depression is placed on the lid. an immunofluorescence assay (ifa) was conducted in which there were two 45 minute incubations and eight separate washes by immersion in pbs. ... | 1990 | 2200105 |
| impact of mass treatment of onchocerciasis with ivermectin on the transmission of infection. | onchocerciasis is a major blinding disease that, until recently, has been essentially untreatable. ivermectin is a safe and effective drug for the mass treatment of onchocerciasis and when used on an individual basis, it reduces the ability of the treated person to transmit onchocerca volvulus infection. in the present study, the effect of community-based ivermectin treatment on the degree of transmission within the community was assessed by determining the incidence of new infection in children ... | 1990 | 2218502 |
| onchocerca volvulus: biochemical and morphological characteristics of the surface of third- and fourth-stage larvae. | the annulated cuticles of third- and fourth-stage larvae of onchocerca volvulus have the typical structure of other nematodes but the cuticle of fourth-stage larvae was thinner. the surface of the third-stage larva was wrinkled and fuzzy, while that of the fourth-stage was smooth. intermediate stages in the formation of the new cuticle and epicuticle beneath the old basal layer and of the separation of the cuticles are shown. monoclonal antibodies specific to the surface of third-stage larvae di ... | 1990 | 2226709 |
| circulating immune complex-associated parasite antigens in human onchocerciasis. | this study identified and characterized parasite antigens in sera from humans infected with onchocerca volvulus. immune complexes were precipitated from human sera with polyethylene glycol and analyzed by immunoblot with rabbit antibodies to o. volvulus. a 23-kda parasite antigen was detected in sera from 17 of 23 nigerian onchocerciasis patients and 5 of 10 endemic controls. other parasite antigens with apparent molecular masses of 62, 66, and 70 kda were less consistently observed. these antig ... | 1990 | 2230240 |
| cloning of specific diagnostic antigens of onchocerca volvulus. | specific, serological diagnosis is one of the main goals in onchocerciasis research. to date this objective has been hampered by (a) scarcity of parasite material, and (b) antigenic cross-reaction between onchocerca volvulus and other nematode species. in order to obtain specific antigens, and in amounts suitable for study, molecular biological techniques have been adopted. a lambda gt11 cdna expression library prepared from o. volvulus adult female worms was screened using infected human sera f ... | 1990 | 2255840 |
| the onchocerciasis focus at kinsuka/kinshasa (republic of zaire) in 1985. ii. parasitological and clinical aspects. | since the antivectorial control in 1948, the parasitological and clinical aspects of the onchocerciasis focus at kinsuka/kinshasa have not been studied further until now. the population examined was selected for its daily contact with the vector. it constituted 143 adults, including fishermen, stonebreakers and women cultivators, and 26 children aged from 10 to 16 years. people were subjected to an ophthalmological examination as well as to an investigation for onchocerca volvulus microfilariae. ... | 1990 | 2256772 |
| possible transplacental transmission of onchocerca volvulus. | in a recent epidemiological study on onchocerciasis on the lower jos plateau in nigeria, a 7-month-old baby delivered by a mother suffering from onchocerciasis showed early clinical signs of the disease: pruritus was present all over the body. the infant's skin snip on incubation revealed microfilariae of onchocerca volvulus. these findings were confirmed 3 months later when the child was re-examined. no onchocercal nodule was found, but pruritus persisted. | 1990 | 2260199 |
| effects of multiple monthly doses of ivermectin on adult onchocerca volvulus. | this paper assesses the effects on adult onchocerca volvulus of monthly doses of ivermectin (150 micrograms/kg) given over 4, 8, and 12 months to patients in guatemala. nodules were removed 4 months after the last dose; the adult o. volvulus were extracted by collagenase digestion, studied by histological techniques, and compared with worms from untreated patients. twelve monthly doses killed a proportion of the adult worms (12% of males and 22% of females), leaving the remainder relatively unaf ... | 1990 | 2267970 |
| identification of the surface polypeptide antigens of the infective larvae of onchocerca volvulus. | the surface polypeptide antigens of third-stage infective larvae (l3) and adult males of onchocerca volvulus have been compared after iodogen-catalysed radioiodination, separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis in beta-mercaptoethanol followed by autoradiography. l3 surfaces contained polypeptides with apparent molecular weights of 14, 18.5, 26, 34, 51, 68 and 130 kda, whereas the adults contained 14, 19, 26, 34, 37.5 and 68 kda components. by immunoprecipitation w ... | 1990 | 2278076 |
| serum-dependent interaction of granulocytes with onchocerca volvulus microfilariae in generalized and chronic hyper-reactive onchocerciasis and its modulation by diethylcarbamazine. | the adherence and cytotoxicity of granulocytes to microfilariae of onchocerca volvulus were examined in vitro. reactivity and modulation by diethylcarbamazine of isolated eosinophilic and neutrophilic granulocytes from patients with generalized and chronic hyper-reactive onchocerciasis (sowda or localized form) from endemic foci in liberia were evaluated under varying serum conditions. in the presence of pooled sera from patients with generalized onchocerciasis granulocytes from both polar group ... | 1990 | 2278077 |
| in vitro effects of ivermectin on onchocerca volvulus microfilariae assessed by observation and by inoculation into simulium damnosum sensu lato. | | 1990 | 2278078 |
| pharmacokinetics of cgp 6140 (amocarzine) after oral administration of single 100-1600 mg doses to patients with onchocerciasis. | the concentrations of cgp 6140 [4-nitro-4'-(n-methyl-piperazinylthiocarbonylamido)-diphenylamine] and of its n-oxide metabolite, cgp 13,231, were measured in plasma and urine after single oral dose of 100-1600 mg of cgp 6140 to 41 fasted ghanaian patients with onchocerca volvulus infections. the absorption of cgp 6140 was rapid and its terminal elimination half-life was about 3 h. the plasma concentrations of cgp 6140 were essentially proportional to the dose. a greater variability in plasma con ... | 1990 | 2291876 |
| the influence of food on the pharmacokinetics of cgp 6140 (amocarzine) after oral administration of a 1200 mg single dose to patients with onchocerciasis. | eleven male patients from mali with onchocerca volvulus infections received in random order a 1200 mg single oral dose of cgp 6140 after an overnight fast and after food intake. the concentrations of cgp 6140 and of its n-oxide metabolite, cgp 13231, were measured in plasma and urine. mean (+/- s.d.) auc cgp 6140 values were 67.0 +/- 10.8 mumol l-1 h in fed and 22.0 +/- 17.2 mumol l-1 h in fasting patients. the mean maximum concentrations (cmax) in plasma +/- s.d. were 12.7 +/- 2.8 mumol l-1 in ... | 1990 | 2291877 |
| onchosim: a model and computer simulation program for the transmission and control of onchocerciasis. | onchosim is a computer program for modelling the transmission and control of the tropical parasitic disease onchocerciasis, or river blindness. it is developed in collaboration with the onchocerciasis control programme in west africa (ocp), and is used as a tool in the evaluation and planning of control operations. the model comprises a detailed description of the life history of the parasite onchocerca volvulus and of its transmission from person to person by simulium flies. the effects of diff ... | 1990 | 2311368 |
| effect of mass treatment of a human population with ivermectin on transmission of onchocerca volvulus by simulium yahense in liberia, west africa. | the impact of mass treatment with ivermectin on the intensity of onchocerca volvulus transmission by the black fly (simulium yahense) was evaluated on the liberian agricultural company rubber plantation in liberia, west africa. the adult pre-treatment prevalence of onchocerciasis was greater than 80%, and the average intensity of infection was 5.35 mf/mg of skin. the drug was administered at 2 annual intervals, reaching 58-60% of the approximately 14,000 people living in 73 camps. landing/biting ... | 1990 | 2316786 |
| putrescine n-acetyltransferase in onchocerca volvulus and ascaris suum, an enzyme which is involved in polyamine degradation and release of n-acetylputrescine. | a novel type of n-acetyltransferase, clearly different from the nuclear and cytosolic polyamine n-acetyltransferases of mammals, was recently found in the intestinal nematode ascaris suum. the occurrence of this putrescine n-acetylating enzyme has also been noted in the filarial parasite onchocerca volvulus. the enzyme was partially purified from adults of o. volvulus and a. suum by chromatography on deae-cellulose and cadaverine-sepharose. substrate specificities of the filarial enzyme resemble ... | 1990 | 2320051 |
| developmentally regulated expression and secretion of a polymorphic antigen by onchocerca infective-stage larvae. | in order to analyse the developmental biology of onchocerca spp. with a view to identifying molecules with specialised functions, we have devised a novel method for labelling proteins synthesised by larvae during growth in the vectors. pulse labelling of onchocerca lienalis by micro-injections of [35s]methionine into blackflies have revealed a major acidic protein of 23 kda which is developmentally expressed almost exclusively by infective, third-stage larvae. the protein appears to be antigenic ... | 1990 | 2320057 |
| in vitro killing of microfilariae of brugia pahangi and brugia malayi by eosinophil granule proteins. | eosinophil infiltration and degranulation around the tissue-invasive stages of several species of helminths have been observed. release of eosinophil granule contents upon the worms is supported by localization of two of the major granule proteins, major basic protein (mbp) and eosinophil peroxidase (epo), on and around species of trematodes, nematodes, and cestodes. in the case of filarial worms, mbp is deposited on degenerating microfilariae (mf) of onchocerca volvulus. here, we performed in v ... | 1990 | 2324497 |
| filarial paramyosin: cdna sequences from dirofilaria immitis and onchocerca volvulus. | the nucleotide sequence of a cdna copy of the dirofilaria immitis paramyosin gene was determined. the sequence was 2545 nucleotides in length, consisting of a single open reading frame of 848 amino acids capable of encoding a protein with a calculated molecular weight of 98,000. the cdna clone was not complete, but probably includes over 97% of the coding region of the gene. we have previously observed that the cloned d. immitis paramyosin is recognized by sera from humans infected with onchocer ... | 1990 | 2325708 |
| a human case of zoonotic onchocerciasis in japan. | a 2-year-old girl living in southwestern japan had a nodule of 2 months' duration on the left foot. a biopsy from the lesion showed transverse sections of a worm surrounded by granulomatous tissue. the worm was identified as an onchocerca sp. from the morphological characteristics such as relatively thick cuticles, annular ridges on the cortical layer, and high somatic muscles. positive serological tests using elisa for onchocerca gutturosa and onchocerca volvulus supported the diagnosis. this w ... | 1990 | 2329217 |
| potential of a soluble tetrazolium/formazan assay for the evaluation of filarial viability. | using female acanthocheilonema viteae we have investigated the bioreduction of the tetrazolium reagent xtt (2,3-bis(2-methoxy-4-nitro-sulphonyl)-5-[(phenylamino) carbonyl]-2h-tetrazolium hydroxide). unlike the formazan formed by other tetrazolium salts, that derived from xtt readily diffuses out of a. viteae in vitro. formazan formation can therefore be quantified by direct absorbance reading of the incubation medium, eliminating the need for a dmso solubilization step. optimum assay conditions ... | 1990 | 2332282 |
| molecular cloning, expression, and chromosome 19 localization of a human ro/ss-a autoantigen. | ro/ss-a antibodies are found in a number of human autoimmune disorders including sjogren's syndrome and several systemic lupus erythematosus-related disorders. these heterogeneous autoantibodies are known to recognize several distinct cellular antigens. with synthetic oligonucleotides corresponding to amino acid sequence information we have isolated a full-length cdna clone which encodes a human ro ribonucleoprotein autoantigen. the 1,890-base pair clone contains an open reading frame that encod ... | 1990 | 2332496 |
| differential length of onchocerca volvulus infective larvae from the cameroon rain forest and savanna. | infective larvae from the savanna strain of onchocerca volvulus are significantly longer (662.6 +/- 66.8 microns; n = 99) than those from the forest strain (624.2 +/- 62.0 microns; n = 236). the length of the infective larvae is not influenced by the size, species or age post infectionem (pi) of the simulium damnosum s. l. vectors nor by their localization in the fly's head, thorax or abdomen, the worm load per fly or the thoracic volume per larva. however, the lengths of infective larvae within ... | 1990 | 2339243 |
| humoral autoimmune response against s-antigen and irbp in ocular onchocerciasis. | autoimmune mechanisms are thought to play a role in the pathogenesis of the chorioretinal changes in ocular onchocerciasis. in this study, the involvement of autoimmunity against retinal antigens in developing chorioretinitis was investigated. serum levels of autoantibodies, directed against human s-antigen and interphotoreceptor retinoid-binding protein (irbp), were determined in patients with onchocerciasis (n = 46) and endemic controls (n = 38) from sierra leone with the use of an enzyme immu ... | 1990 | 2365568 |
| a human ro/ss-a autoantigen is the homologue of calreticulin and is highly homologous with onchocercal ral-1 antigen and an aplysia "memory molecule". | the ro/ss-a (ro) autoantigens consist of at least four immunologically distinct proteins which are recognized by autoantibodies typically found in sera from patients with primary sjogren's syndrome and in subsets of patients with lupus erythematosus. we recently isolated a 1.9-kb human cdna clone which encodes one of these ro autoantigens. synthetic oligonucleotides corresponding to the human ro sequence were used to amplify the homologous gene from a murine b cell cdna library using the polymer ... | 1990 | 2365822 |
| epidemiological impact of vector control. i. incidence and changes in prevalence and intensity of onchocerca volvulus infection. | since 1974, the onchocerciasis control programme (ocp) has been engaged in a large scale attempt to control the savanna species of the vector of onchocerciasis in seven west african countries. the effect of the vector control effort has been measured by epidemiological evaluation. for this purpose 474 villages have been examined by means of skin snip surveys between 1975 and 1983 and of these, 184 have been retained to-date for follow-up surveys which have documented over the years the reduction ... | 1990 | 2378200 |
| decline in onchocerciasis in the eastern usambara mountains, north eastern tanzania, and its possible relationship to deforestation. | a survey to establish the extent and possible impact of deforestation and increased farming activities on the prevalence of onchocerciasis was carried out in all the 17 villages in the eastern usambara mountains. results revealed that the disease is widespread. out of 2,968 inhabitants of all ages skin-snipped in 1984 in the area, 22.7% were positive for onchocerca volvulus microfilariae. the infection rates in the under nineteen and under ten age groups were 10.3% and 6.6% respectively. the ove ... | 1990 | 2378202 |
| population decline of simulium woodi and reduced onchocerciasis transmission at amani, tanzania, in relation to deforestation. | to investigate an apparent decline of the onchocerciasis vector simulium woodi, in the simulium neavei group, weekly 12-hour biting catches on man were carried out for 13 months near amani and compared with those obtained 22 years earlier. the results showed a marked fall in biting s. neavei s.l. females and supported earlier findings on the aquatic stages. the mean biting-catch in 1985/6 was only 13% of that in 1963/4 and comprised 91% s. woodi and 9% the more common, but largely zoophilic, sim ... | 1990 | 2378204 |
| observations on the reproductive biology of onchocerca volvulus. | this study compiles observations on the reproductive capacity of o. volvulus. adult parasites enzymatically isolated from excised onchocercomata of untreated and chemotherapeutically treated patients, and from inhabitants living in areas with long vector control, were investigated to assess their fecundity. changes of microfilaria development in utero and microfilaria release were assessed or estimated after treatment of patients with micro-filaricidal drugs that interfered with the development ... | 1990 | 2378210 |
| in vitro assessment of the activity of anthelmintic compounds on adults of onchocerca volvulus. | the viability of adult onchocerca volvulus and the effect of 12 known anthelmintic compounds on the parasites have been evaluated in an in vitro culture system. three different parameters, a colorimetric assay, using nadh-dependent reduction of a tetrazolium salt to dark blue formazan by living adult worms, motility indices of male worms and lactate excretion of female worms were used to determine worm viability. the experiments showed that over a short term period of six days the viability of t ... | 1990 | 2378212 |
| molecular cloning of immunorelevant onchocerca volvulus antigens. | | 1990 | 2378213 |
| novel onchocerca volvulus filaricides from carapa procera, polyalthia suaveolens and pachypodanthium staudtii. | suitable drugs for the elimination of adult onchocerca volvulus are still needed since ivermectin, the new microfilaricide, appears to be ineffective against this parasite stage. herein we report on the identification of filaricides in three medicinal plants. the compounds carapolide a, mexicanolide-methylangolensate mixture from carapa procera and oliverine from polyalthia suaveolens or pachypodanthium staudtii when tested at 10-100 micrograms.ml-1 were found to exhibit considerable microfilari ... | 1990 | 2378219 |
| onchocerciasis in benue state of nigeria. vi. the prevalence and distribution of the disease among the human population in sati-ikyov village. | following our report on onchocherciasis among the ikyov and nanev clans, we initiated a survey of the prevalence and distribution on onchocerciasis in some villages in benue state, nigeria. out of the 1,558 inhabitants (619 males and 608 females) examined, 1,227 (78.8%) were found to carry microfilariae (mf) of onchocerca volvulus (mean density: about 20/skin snip). the presence and number of mf from the right and left iliac crests were comparable. the findings indicate that clinical manifestati ... | 1990 | 2378227 |
| effect of ivermectin on the vertical distribution of onchocerca volvulus microfilariae in the skin. | a new technique for assessing vital and degenerative microfilariae (mf) in different skin layers of onchocerciasis patients is described. vertical sections at least 5 mm deep were collected from the surgical nodulectomy wounds before and 2, 4 and 28 days after treatment with ivermectin and fixed in ethanol. skin biopsies were punched horizontally with trephines and digested enzymatically with collagenase. in untreated biopsies 80% of the mf were located in the uppermost layer of 1 mm and only 1. ... | 1990 | 2382096 |
| the predicted and observed decline in onchocerciasis infection during 14 years of successful control of simulium spp. in west africa. | in 55 villages from the well-protected central area of the onchocerciasis control programme in west africa (ocp), skin snip surveys have been carried out at regular intervals since the programme started, and the latest round of surveys was undertaken after 12-14 years of successful vector control. the observed trends in the prevalence and intensity of onchocerciasis infection in cohorts of adults were compared with the trends predicted using a host-parasite model. after 12-14 years of control th ... | 1990 | 2393979 |
| structural homology between the rat calreticulin gene product and the onchocerca volvulus antigen ral-1. | | 1990 | 2395661 |
| [onchocerciasis in travelers to the tropics]. | two men, aged 54 and 31 years respectively, developed an itching skin rash 18 and 6 months respectively after returning from a trip to africa, the former also recurrent conjunctivitis. two years and 6 months, respectively, passed from the time of first symptoms until the diagnosis of onchocerciasis was made. both patients had an eosinophilia (10.5 and 19%) and specific antibodies against onchocerca volvulus. microfilaria were demonstrated in the skin of the younger man. the other one had bilater ... | 1990 | 2401191 |
| antigens of onchocerca volvulus. | most studies on immunologic responses to onchocerca volvulus have employed extracts or antigens from related filarial parasites. consequently, little is known about the nature of o. volvulus antigens. potential antigen sources include in vitro cultures and physicochemical fractionation of o. volvulus extracts. ige antibody responses to a wide range of antigens occur in patients with onchocerciasis, but there is little evidence of species specificity in serologic tests. some potent allergens are ... | 1985 | 2416027 |
| studies on a filarial antigen with collagenase activity. | we examined the ability of two filarial species, onchocerca volvulus and brugia malayi, to solubilize collagen molecules from native collagen fibrils. collagenolytic activity was detected in extracts of adult worms, in living microfilariae of o. volvulus and in live infective larvae and adult female worms of b. malayi. excretion-secretion factors produced in vitro by infective larvae of b. malayi also contained large amounts of collagenase. studies with enzyme inhibitors suggest that the latter ... | 1986 | 2423872 |
| identification of antigens of onchocerca volvulus and onchocerca gibsoni for diagnostic use. | adults of onchocerca volvulus and onchocerca gibsoni were identically fractionated into a surface-enriched fraction, a phosphate buffered saline (pbs) extract and a pbs insoluble-detergent soluble fraction. glycoproteins were prepared from these extracts and all fractions were examined by the western blot technique using sera from individuals infected with a variety of filarial and non-filarial nematode worms. using antisera to o. volvulus, a number of antigens were demonstrated in all of the ex ... | 1986 | 2429180 |
| antigenic similarity of onchocerca volvulus to other helminths examined by monoclonal antibodies against o. volvulus. | antigens in onchocerca volvulus were characterized using anti-o. vovulus monoclonal antibodies (mcab). a total of 17 mcab which were not species-specific to o. volvulus was examined for the antigenic similarity of o. volvulus with 12 parasitic helminths using indirect immunofluorescence. the range of reactivity of these mcab was wider in nematodes in contrast to species of cestoda or trematoda. the antigenic similarity within helminths examined was generally in agreement with their taxonomic rel ... | 1986 | 2434696 |
| isolation of an antigenic fraction for diagnosis of onchocerciasis. | a surface enriched fraction was prepared from adults of onchocerca volvulus by brief extraction of entire worms with detergent. this was then gel filtered to yield a low molecular weight fraction which functioned specifically in elisa analysis. an identical result was also obtained when the related cattle parasite, o. gibsoni, was similarly fractionated and tested. the low molecular weight fraction contained at least four antigenic components when examined by coprecipitation and immunoblotting s ... | 1987 | 2436130 |
| isolation and characterization of expression cdna clones encoding antigens of onchocerca volvulus infective larvae. | the isolation of recombinant cdna clones expressing antigens found in onchocerca volvulus infective larvae is described. to isolate such clones, an expression cdna library constructed from adult o. volvulus rna was screened with antiserum raised against infective larvae. one clone, designated lambda ral-1 was characterized further. the recombinant antigen produced by lambda ral-1 stimulates proliferation of peripheral blood mononuclear cells from o. volvulus infected humans. lambda ral-1 is deri ... | 1988 | 2455736 |
| experimental interstitial keratitis induced by onchocerca volvulus antigens. | to elucidate the pathogenic mechanisms involved in onchocercal sclerosing keratitis in humans, we developed a model of onchocercal interstitial keratitis in guinea pigs. onchocerca volvulus antigens injected intrastromally into corneas of preimmunized hartley guinea pigs induced an intense stromal keratitis with corneal edema, neovascularization, and infiltration with acute and chronic inflammatory cells. this reaction subsided after two weeks. repeated intrastromal injection resulted in an exac ... | 1988 | 2460073 |
| construction of onchocerca volvulus cdna libraries and partial characterization of the cdna for a major antigen. | adult onchocerca volvulus were isolated from nodules removed from onchocerciasis patients at four locations--two in the west african sudan-savanna region (near bamako, mali, and touboro, cameroon), one in a west african forest region (kumba, cameroon) and one near guatemala city, guatemala. four different cdna expression libraries were constructed in bacteriophage lambda gt11 using poly(a)+ rna from the adult female worms. individual cdna clones of single copy genes were used to compare the geno ... | 1988 | 2464764 |
| special requirements for use of adult onchocerca volvulus in molecular biology. | | 1988 | 2465564 |
| phosphocholine epitopes on helminth and protozoal parasites and their presence in the circulation of infected human patients. | antigens containing phosphocholine (pc) circulate in the blood during chronic filarial infection. because of the wide occurrence of such pc epitopes, we examined their specificity by evaluating 10 common parasites of humans for the presence of pc epitopes, and sera from patients infected with these parasites for circulating antigens containing pc. immunoblot analysis of extracts from various parasites using an anti-pc monoclonal antibody (ca101) demonstrated the presence of pc epitopes on the pr ... | 1989 | 2482559 |
| a lambda gt11 cdna recombinant that encodes dirofilaria immitis paramyosin. | the cdna synthesized from mrna of dirofilaria immitis female adult worms was cloned into the expression vector lambda gt11. screening the library with a hyperimmune rabbit antiserum raised against adult worm homogenates yielded several antigen positive clones. one of these clones, lambda cdi2, was recognized by rabbit antisera raised against either d. immitis l-3, adult, brugia malayi l-3 or onchocerca volvulus adult worm antigen, as well as by antisera from humans naturally infected with o. vol ... | 1989 | 2527335 |
| an oligonucleotide probe specific for onchocerca volvulus. | a genomic dna library of a liberian strain of onchocerca volvulus was prepared in the vector bacteriophage lambda gt10. the library was differentially screened by hybridisation with radiolabelled total dna from the homologous parasite, two heterologous onchocerca parasites (onchocerca gibsoni and onchocerca gutturosa) and human liver cells. a clone (c1a1) was isolated whose binding to o. volvulus dna was at least 50 times stronger than to the other parasite dna samples. no binding was observed w ... | 1989 | 2528065 |
| [pruritus after taking chloroquine and filariasis]. | a study of relations between pruritus after doses of chloroquine and on the one hand the infection by mansonella perstans (filariasis frequent in some areas but pathogenic) and on the other hand the infection by onchocerca volvulus (filariasis frequent in some other areas but not very pathogenic) was carried out in two villages in ivory coast. it is not possible to show an obvious relation between the presence of pruritus and the two filariasis. | 1989 | 2545369 |
| a preliminary assessment of the feasibility of evaluating promising antifilarials in vitro against adult onchocerca volvulus. | the suitability of motility indices and tetrazolium-based colorimetric assays for the determination of the viability of adult onchocerca volvulus after in vitro exposure to potential macrofilaricides has been examined. experimentation showed that both techniques could be applied to adult o. volvulus, although the variability between individual worms necessitated the use of large experimental groups. the potential of using cut anterior tips of female o. volvulus for screening was also investigate ... | 1989 | 2558338 |
| ocular onchocerciasis and intensity of infection in the community. ii. west african rainforest foci of the vector simulium yahense. | a novel method of analysis was used to describe community patterns of ocular onchocerciasis in relation to the intensity of infection in west african forest villages where s. yahense is the sole vector. the pattern is completely different from that found in the savanna, even after correction for the intensity of infection as measured by the community microfilarial load (cmfl). lesions of the anterior segment of the eye as well as onchocercal blindness either do not occur or occur only sporadical ... | 1989 | 2559472 |
| activity of thiocarbamazine in patients dually infected with schistosoma and onchocerca volvulus. | | 1989 | 2564535 |
| parasitologic survey of onchocerca volvulus infection in the nimiyama chiefdom, kono district, sierra leone. | infection due to onchocerca volvulus was investigated in the nimiyama chiefdom, kono district, sierra leone, where simulium damnosum s.l. is known to breed but no data on the prevalence and intensity of o. volvulus infection exists. of the 735 individuals sampled by the skin snip method in five villages, 471 (64%) were infected. the infection rate for males was significantly (p less than 0.05) higher than that of the females. two hundred and ninety-one (70.0%) of the 416 males skin snipped and 1 ... | 1989 | 2595798 |
| effects of intermediary metabolites and electron transport inhibitors on action of chloroquine on brugia pahangi and onchocerca volvulus. | we examined the possibility that chloroquine is interfering with aerobic energy-generating processes in the adult filarial parasites, brugia pahangi and onchocerca volvulus. using motility of these parasites as an assay of drug effect, we found that micromolar concentrations of chloroquine caused significant paralysis, but only in alkaline medium (ph 8.4). the addition of 12 mm glutamine or 10 mm albizziin to the medium completely antagonized drug-induced paralysis. in addition, in b. pahangi, a ... | 1989 | 2597203 |
| onchocerciasis endemic in the state of bolivar, venezuela. | microfilariae of onchocerca volvulus were demonstrated by single shoulder-skin biopsy in 42.8% of inhabitants of seven amerindian villages in an area of approximately 10,000 km2, near the brasilian roraima territory. the highest prevalence was found among the yanomama indians of chajuraña (84.6%, with a mean of 61.3 microfilariae per mg of skin). the six other communities were affected, but with lower prevalence and microfilaria skin densities. the absence of lymphoedema and the few subcutaneous ... | 1989 | 2604478 |