| specific and sensitive igg4 immunodiagnosis of onchocerciasis with a recombinant 33 kd onchocerca volvulus protein (ov33). | the full length cdna of the immunodominant ov33 protein of onchocerca volvulus was expressed in e. coli using various vector constructs. expression was best with the vectors pgex2t and pcg808fx, yielding fusion protein ov33-gst and ov33-mbp, respectively. purified fusion protein ov33-gst and o. volvulus antigen extracts (ovag) were used to compare antibody responses (igm and igg-subclasses) of patients infected with o. volvulus, brugia malayi, wuchereria bancrofti, mansonella perstans/loa loa an ... | 1992 | 1281926 |
| characterization of a muscle-associated antigen from wuchereria bancrofti. | a recombinant clone, wbn1, isolated from a genomic expression library of wuchereria bancrofti and showing restricted specificity at the dna level (southern and pcr analyses) for wuchereria bancrofti and brugia malayi has been previously described. sequence analysis of wbn1 indicated that it had notable similarity to myosin. further characterization using in situ hybridization has localized the mrna in the muscle of the adult parasite and in the microfilariae. rabbit polyclonal antiserum, raised ... | 1992 | 1283597 |
| identification and characterization of a parasite antigen in the circulating immune complexes of onchocerca volvulus infected patients. | a peg-elisa was used to demonstrate parasite specific immune complexes in a significant proportion (25/26) of onchocerca volvulus infection sera from sierra leone. the parasite antigen was detected using a peroxidase-conjugated rabbit serum raised to the bovine parasite o. gibsoni. controls including european control serum, endemic control serum and rh+ sera gave consistently low readings. characterization of the parasite component in the immune complexes by western blotting demonstrated a heat ... | 1992 | 1284095 |
| adverse reactions after community treatment of onchocerciasis with ivermectin in guatemala. | male and female residents on a guatemalan coffee plantation where onchocerca volvulus infections were hyperendemic were offered oral ivermectin (100-200 micrograms/kg) as part of a community-wide treatment programme for onchocerciasis. forty-five persons were treated and then questioned daily for 28 d about changes in their health. those with complaints were monitored until all signs and symptoms had resolved. sixty-seven percent complained of some adverse event after treatment; 60% developed ob ... | 1992 | 1287939 |
| the effect of repeated doses of ivermectin on adult female onchocerca volvulus in sierra leone. | the effects of single and multiple doses of ivermectin on mortality and morphology were assessed in over 700 female onchocerca volvulus worms and the effects on embryogenesis were assessed in 490. nodules were surgically removed from sierra leoneans recruited from a double-blind placebo controlled study of ivermectin given at six-monthly intervals. nodules were digested in collagenase to isolate whole adult worms. after four or five doses of ivermectin there were significant increases in the num ... | 1992 | 1293732 |
| the selection of communities for treatment of onchocerciasis with ivermectin. | in areas endemic for onchocerciasis, active community-based treatment with ivermectin is preferred to individual diagnosis and treatment. ideally, all infected persons should be treated, although initially priorities may have to be set at local or national levels. we suggest that all communities with a prevalence of o. volvulus infection of 20% or more in adult males aged 20 years or over should be treated; and that elsewhere facilities for passive treatment should be provided. in some areas, fo ... | 1992 | 1293734 |
| non-ocular clinical onchocerciasis in relation to skin microfilaria in the taraba river valley, nigeria. | examination of 2,876 persons in fourteen communities was carried out for clinical onchocerciasis on the taraba river valley, nigeria, where parasitological findings indicate unusually high endemicity. forty-five percent of the population had at least one type of skin lesion or the other, the commonest of which was pruritus. thirty-two percent had nodules. some of the nodules were located in unusual sites such as the mammae, anus. nodule carriage and nodule-load as well as lymphatic enlargement w ... | 1992 | 1300353 |
| human onchocerciasis in the lower jos plateau, central nigeria: the prevalence, geographical distribution and epidemiology in akwanga and lafia local government areas. | an investigation of human infection with onchocerca volvulus and the resulting clinical disease was carried out for the nigerian national onchocerciasis control programme between july and august 1989 [corrected]. the survey covered 10.6% of the rural population in 41 savanna villages of central nigeria. of the 8451 self-selected individuals examined, 900 (10.6%) had skin microfilariae (mf). there were differences between villages in both endemicity and intensity of infection, but in general the ... | 1992 | 1304706 |
| inhibition of carbohydrate uptake of onchocerca volvulus infective larvae (l3) by effector cell constituents. | the in vitro killing of onchocerca volvulus infective third stage larvae (l3) by components of their human hosts' defence mechanisms is not well documented, as no suitable assay exists. motility is inappropriate as a criterion of larval viability because of the unsteady winding movements of l3. in the present study, a metabolic parameter for larval viability, the uptake of [3h]2-deoxy-d-glucose, was evaluated. to demonstrate the reproducibility and validity of this test, the oxygen radical hydro ... | 1992 | 1329684 |
| hydrolytic activity of an onchocercoma. | the onchocercoma or nodule produced by the nematode onchocerca volvulus (filarioidea) in the skin of patients suffering from onchocerciasis has not been examined by histochemical techniques. in this work we have used histochemical techniques to evaluate 5 hydrolytic enzymes, namely phosphatases, esterases and beta-glucuronidase. the results show increased enzymatic activity at the sites of major metabolic activity and within reactive cells including macrophages (mc) and giant cells (gc) of the o ... | 1992 | 1343736 |
| [entomology of onchocercosis in soconusco, chiapas. 6. quantitative studies of the transmission of onchocerca volvulus by 3 species of simuliidae in a community with high endemicity]. | in guatemala, there is no doubt about the participation of simulium ochraceum as vector of onchocerciasis. however, in mexico practically there are not studies focussed to determine the role of this species in the transmission. the objective of the present investigation was to determine which of the 3 species of simulium founded in the soconusco region of chiapas, is the main, and which were secondary in the transmission of onchocerciasis in that area. the locality of morelos, in the huixtla "mu ... | 1992 | 1345118 |
| eye lesions, blindness and visual impairment in the taraba river valley, nigeria and their relation to onchocercal microfilariae in skin. | 2876 persons in fourteen communities in the taraba river valley, nigeria were examined for eye lesions and tested for visual acuity using the 'tumbling e'. the individuals were also examined for microfilaria of onchocerca volvulus. more than one-tenth of the population were blind, while another 16.1% had visual impairment. the prevalence of blindness was in excess of 20% in six communities, with one community recording 71.9% blindness rate. all forms of visual involvement increased with age but ... | 1992 | 1354932 |
| distribution and severity of onchocerciasis in southern benin, ghana and togo. | the onchocerciasis control programme in west africa has recently extended its operation in southern benin, ghana and togo. to estimate the number of people infected and blinded by onchocerciasis and to describe the distribution and severity of the disease in the extension area, 99 villages were selected, using a stratified random sampling procedure, and surveyed. all the ecological and entomological information available was used in the sampling procedure and in the selection of 87 non-represent ... | 1992 | 1363185 |
| a monoclonal antibody-based immunodiagnostic assay for onchocerciasis. | five murine monoclonal antibodies raised against onchocerca volvulus cuticular extracts and termed movs (1-4 and 6) were selected based on reactivity with o. volvulus cryosections, and non-reactivity with cryosections of human skin and/or nodular tissue. two others movs 5 and 7 reacted with both. using the peroxidase-anti- peroxidase (pap) histochemical method, the target epitopes of mov 1 were located in the cuticle's basal and cortical layers, those of mov 2 in the cortical layer; whilst mov 3 ... | 1992 | 1381517 |
| ivermectin does not reduce the burden of itching in an onchocerciasis endemic community. | degrees of itching were estimated before and for 6 months after a fourth dose of ivermectin or placebo was given to 97 subjects in sierra leone. there was no reduction in itching attributable to ivermectin at any stage, but there were non-significant increases in the prevalence, severity and localization of itching within the first 2 months after ivermectin compared to placebo. we also found that cell-mediated immune responses to onchocerca volvulus were significantly increased 4 weeks after a s ... | 1992 | 1412653 |
| filariasis in gongola state nigeria. i: clinical and parasitological studies in mutum-biyu district. | a total of 2,552 persons living in 9 villages along the benue river valley, mutum biyu district of gongola state, nigeria were examined between october and december 1989 for filariasis. it is the first time a filariasis survey will be carried out in this state. 276 (10.8%) had wuchereria bancrofti, 50 (2.0%) had loa loa, 281 (11.0%) were positive for mansonella perstans while 12 (0.5%) were positive for onchocerca volvulus. villages located near the benue river had higher prevalence rates than t ... | 1992 | 1416217 |
| the actin genes of onchocerca volvulus. | the genome of onchocerca volvulus was found to contain 2 actin gene classes (called 1 and 2) of 2 genes each. the 4 genes are located in 2 clusters (called a and b), each containing a gene class member. five short introns of 122-207 bp occur within each gene. the sequences of the fourth intron and the 5' and 3' untranslated regions of all the 2 gene classes are completely different even though their coding regions share 95% identity. mature transcripts from the actin genes have the nematode spli ... | 1992 | 1435869 |
| albendazole in the treatment of onchocerciasis: double-blind clinical trial in venezuela. | a double-blind clinical trial was conducted in monagas state, venezuela to assess the tolerance and efficacy of albendazole in the therapy of onchocerca volvulus infection. forty-nine patients (26 treated and 23 controls) received a 10-day course of albendazole (400 mg/day) or a placebo. consistent with the excellent tolerance observed, albendazole did not kill microfilariae. however, analysis of changes in microfilarial densities (mf/mg of skin) over one year showed that albendazole was active ... | 1992 | 1443350 |
| [fever, eosinophilia, and subcutaneous nodules. onchocerciasis. onchocerca volvulus (river-blindness)]. | | 1992 | 1450263 |
| [molecular biological techniques in the diagnosis of tropical parasitic diseases]. | recent advances in the development of molecular biological techniques have resulted in their supplementary application for improved diagnosis of tropical parasitic diseases. the main areas of interest are the production of recombinant antigens for immunodiagnosis, and the detection of parasites by hybridization of nucleic acids and by dna amplification (pcr) in vitro. | 1992 | 1465149 |
| epilepsy and retarded growth in a hyperendemic focus of onchocerciasis in rural western uganda. | an unusually high number of patients with epilepsy was observed in kyarusozi sub-county, where infection with onchocerca volvulus is hyperendemic. a preliminary survey was carried out in april 1991, when all patients with epilepsy and growth retardation were invited for medical examination. two hundred and thirty one patients were screened, of whom, 91% were below the age of 19 years. the infection rate with onchocerca volvulus in patients with epilepsy (61%) and retarded growth (70%) was signif ... | 1992 | 1473507 |
| identification of circulating parasite acetylcholinesterase in human and rodent filariasis. | in the present study, the enzyme acetylcholinesterase (ache) from filarial parasites was identified in sera from humans infected with onchocerca volvulus as well as in mastomys natalensis infected with brugia pahangi. the enzyme was present in immune complexes precipitated with cold 4% polyethylene glycol. the infected sera showed 3-4 times more ache activity than did normal sera, and enzyme activity could be demonstrated in 5% polyacrylamide gels by specific staining. the enzyme from infected s ... | 1992 | 1480604 |
| filarial parasites contain a ras homolog of the tc4/ran/spil family. | we have isolated and characterized a gene encoding a novel gtp-binding protein of the gtpase superfamily in the filarial parasites brugia malayi and onchocerca volvulus. the deduced amino acid sequence of the cloned molecule has approximately 30% overall homology to ras proteins and approximately 90% homology to the 'ras-like' nuclear proteins tc4, ran and spil. rabbit antisera to bacterially expressed filarial protein detect a 24-22 kda doublet in extracts of adult b. malayi and mature microfil ... | 1992 | 1484550 |
| onchocerca volvulus infection in sierra leone: relation between prevalence, intensity of infection, and ocular problems in a 'forest' region. | a two-year longitudinal study carried out in five villages in a forest region of gorama chiefdom, kono district, sierra leone, revealed that infection with onchocerca volvulus was hyperendemic, the overall rate of infection being 61.6%. prevalence rose from 28.6% in the 1-5-year age group, peaking among the 21-30-year age group (82.5%) and then levelling off. the intensity of infection though low, peaked in the 31-40-year-old males and in the 41-50-year-old female cohorts. the iliac crest was mo ... | 1992 | 1485496 |
| onchocerciasis in the forest-savannah mosaic region of sierra leone. prevalence, intensity of infection, and endemicity levels. | the present study was carried out between december 1986 and january 1988. a series of 3,048 individuals (46% males and 54% females) were examined in 56 villages; onchocercal dermatitis and lymphadenitis were seen. the crude prevalence of nodules and of microfilariae amounted to 14% and 43%, respectively. the prevalence of nodules was significantly higher at the femoral trochanter than at other anatomical sites. the overall prevalence of nodules, and of microfilariae, was significantly higher in ... | 1992 | 1485497 |
| the skin and the immune response in onchocerciasis. | | 1992 | 1492378 |
| onchocerca volvulus: frequency of codon usage. | | 1992 | 1493878 |
| microepidemiology of onchocerciasis in guatemala: dispersal and survival of simulium ochraceum. | wild simulium ochraceum females, both blood engorged and non-blood engorged, were collected from human volunteers infected with onchocerca volvulus, marked with fluorescent dyes, and released from the same locality as they were collected during february and march 1989. a small hyperendemic village located within 0.5 km of streams supporting large populations of s. ochraceum larvae served as the site for both collection and release of adult females. fifteen sites for the recapture of flies were l ... | 1992 | 1503184 |
| ivermectin: reduction in prevalence and infection intensity of onchocerca volvulus following biannual treatments in five guatemalan communities. | residents of five hyperendemic communities located in the central focus of onchocerciasis in guatemala were treated with ivermectin (mectizan) or placebo every six months for 30 months. the effects of treatment on prevalence and the intensity of skin infection (microfilarial skin density [mfd]) were evaluated. significant and persistent reductions in both of these indices were achieved by coverage of 80.7% of the eligible populations. the highest proportionate reductions in both indicators of in ... | 1992 | 1503185 |
| the effects of repetitive community-wide ivermectin treatment on transmission of onchocerca volvulus in guatemala. | the effects of biannual ivermectin treatment at the community level on transmission of onchocerca volvulus during the dry season were measured over a 30-month period in guatemala. in the los tarrales transmission zone, an area encompassing three villages, significant changes occurred in both the prevalence and quantity of infection in the simulium ochraceum vector population. these included a 76% reduction in females with infective stage larvae (l3s) and an 80% reduction in number of l3s per 1,0 ... | 1992 | 1503186 |
| molecular cloning and characterization of onchocystatin, a cysteine proteinase inhibitor of onchocerca volvulus. | a cdna clone designated ov7 encodes a polypeptide that corresponds to a highly antigenic onchocerca volvulus protein. ov7 has significant amino acid sequence homology to the cystatin superfamily of cysteine proteinase inhibitors. in this report we establish that the ov7 recombinant protein is active as a cysteine proteinase inhibitor, and we have named it onchocystatin. it contains a cystatin-like domain that inhibits the activity of cysteine proteinases at physiological concentrations. recombin ... | 1992 | 1512269 |
| anti-onchocerca volvulus immunoglobulin subclass response in children from sierra leone. | the humoral immune responses of a paediatric population of 224 children, 2-15 years of age, residing in an onchocerciasis endemic area of sierra leone, were studied to gain information that may be useful in the serodiagnosis of prepatent and low-level infections with onchocerca volvulus. the antigen-specific levels of igg and igg4 were determined and evaluated in the context of the parasitological status of the child. over 87% of the microfilaria-negative children had significant levels of antig ... | 1992 | 1514051 |
| cell-mediated and monoclonal antibody-dependent killing of onchocerca volvulus microfilariae. | to identify the target antigens implicated in the adherence and killing of microfilariae (mf) by leucocytes, we incubated nodular mf and leucocytes in the presence of anti-cuticular monoclonal antibodies (movs) and fresh serum. leucocyte donors were patients with a mean age of 37 years (with 0-1 mf/snip), who had lived in the endemic village studied for at least 10 years. after 16-20 h of incubation, up to 74% of the mf could be seen with 10 or more cells adhering to them. by 36-40 h up to 54% o ... | 1992 | 1514052 |
| ivermectin-facilitated immunity in onchocerciasis. reversal of lymphocytopenia, cellular anergy and deficient cytokine production after single treatment. | a longitudinal investigation has been conducted into the cell-mediated immune responses of onchocerciasis patients after a single-dose treatment with ivermectin. untreated patients tested for delayed cutaneous hypersensitivity (dch) to seven recall antigens showed lower responses than infection-free control individuals (p less than 0.01), but 6 and 14 months after treatment dch reactions increased to similar levels to those seen in the controls. the in vitro cellular reactivity to onchocerca vol ... | 1992 | 1516257 |
| onchocerciasis prevalence in previously known foci in western uganda: results from a preliminary survey in kabarole district. | a prevalence survey of onchoceriasis was done in kabarole district, uganda, in 1990. the objective was to determine the prevalence of onchocerciasis among communities living in previously known foci. a total number of 1186 persons was included in the study. the infection rate among the communities studied ranged from 0% to 67%. the most frequent clinical signs and symptoms of onchocerciasis were: pruritus (80%), rough skin (46%), skin rash (30%), leopard skin (6%) and sclerosing keratitis (7%). ... | 1992 | 1519030 |
| effects of three-month doses of ivermectin on adult onchocerca volvulus. | onchocerca volvulus worms in nodules from guatemalan patients treated with four, eight, or 11 single doses of ivermectin (150 micrograms/kg of body weight) that were given once every three months were examined by routine histologic techniques and compared with worms in control nodules from untreated persons living in the same location over the same time periods. all treated nodules were removed four months after the last dose of ivermectin, i.e., 13, 25, or 34 months after the start of the trial ... | 1992 | 1539754 |
| identification and characterization of an onchocerca volvulus cdna clone encoding a microfilarial surface-associated antigen. | the identification and characterization of a recombinant cdna clone (ov103) expressing a microfilarial surface-associated antigen of onchocerca volvulus is described. ov103 was identified and isolated from a lambda gt11 cdna expression library derived from adult o. volvulus mrna using a chimpanzee antiserum, taken 2 years after infection with third-stage larvae of o. volvulus. the cdna clone encodes a 12.5-kda protein that corresponds to a 15-kda parasite protein present in microfilariae and adu ... | 1992 | 1542318 |
| morphometric differentiation of onchocerca volvulus and o. ochengi infective larvae. | by microinjection of cryopreserved microfilariae (mf) into nulliparous flies, a comparison of the lengths of the infective larvae (l3) of onchocerca volvulus and o. ochengi from the head of simulium damnosum s.l. (presumed s. sirbanum) has been made. the suitability of s. sirbanum as a host was similar for both onchocerca spp. the mean length +/- standard deviation of o. ochengi infective larvae measured in aqueous medium after storage of infected flies in liquid nitrogen was 762 +/- 63 microns ... | 1992 | 1566310 |
| the viability of adult onchocerca volvulus after long-distance transportation. | | 1992 | 1566311 |
| [effect of a sublethal dose of an insect growth regulator on the physiology of onchocercosis vectors]. | in most of the large scale vector control programs, the larviciding operations are not fully successful, resulting in a surviving vector population due to the use of sublethal doses. this problem leads the authors to study the effect of such doses upon the future of the residual population in order to know if it represents an epidemiologically dangerous population. one insect growth regulator was selected to study this phenomenon using onchocerca volvulus as the parasite and simulium damnosum s. ... | 1992 | 1567265 |
| onchocerca volvulus dna probe classification correlates with epidemiologic patterns of blindness. | onchocerciasis, or river blindness, results from infection with onchocerca volvulus. the parasite is endemic to west africa, in both rain forest and savanna bioclimes. several lines of evidence suggest that different strains of the parasite exist in the rain forest and savanna. furthermore, epidemiologic evidence indicates that ocular onchocerciasis is most severe in savanna regions. this has led to the hypothesis that there is a strain association with ocular pathology. to test this hypothesis, ... | 1992 | 1569351 |
| the profile of igg and igg subclasses of onchocerciasis patients. | in this study onchocerca gutturosa was compared with o. volvulus in an elisa test to detect onchocerca-specific igg and igg subclasses. the test was developed and standardized to detect onchocerca-specific igg and igg subclasses in sera of onchocerciasis patients and endemic controls. onchocerca volvulus and o. gutturosa crude water-soluble antigens showed no significant difference in detecting onchocerca-specific igg antibody (t = 1.88, p greater than 0.05). the levels of igg subclasses varied ... | 1992 | 1572089 |
| onchocerca volvulus: immunization of chimpanzees with x-irradiated third-stage (l3) larvae. | to provide a theoretical basis for the potential development of vaccines against onchocerca volvulus (ov) a trial has been conducted to assess the protective efficacy of immunization of chimpanzees with x-irradiated l3 larvae. approximately 1000 larvae were injected at 0, 1, and 7 months. the immunized animals, and unimmunized controls, were then challenged with 250 live l3. in order to provide possibly protective exposure to the immunologically distinct l4 epicuticle, a radiation dose (45 krad) ... | 1992 | 1582477 |
| experimental onchocerciasis in chimpanzees. antibody response and antigen recognition after primary infection with onchocerca volvulus. | nine of 18 chimpanzees inoculated with 250 infective third-stage larvae (l3) each developed patent (i.e., positive for microfilariae) onchocerca volvulus infection. four of 6 infected chimpanzees that received 200 micrograms/kg ivermectin at 28 days postinfection (pi) became patent, whereas, when ivermectin was given concurrently with l3 challenge only 1 of 6 infected animals developed patent infection. the antibody response to o. volvulus adult worm-derived antigens (ovag) showed clear differen ... | 1992 | 1592090 |
| analysis of antibody responses directed against two onchocerca volvulus antigens defined by monoclonal antibodies. | monoclonal antibodies, reactive with antigens solubilised from the body wall of intact female onchocerca volvulus using 2% 2-beta-mercaptoethanol, have been characterised. two igg1 antibodies, cam1 and cam28, recognised antigens of apparent molecular weights of 18,000 and 28,000; and 120,000, respectively. the target antigens of cam1 and cam28 could be localised in the cuticle. inhibition elisas showed that target epitopes of both monoclonal antibodies induce an antibody response in onchocercias ... | 1992 | 1598508 |
| serological cross-reactivity between a human ro/ss-a autoantigen (calreticulin) and the lambda ral-1 antigen of onchocerca volvulus. | we have cloned and sequenced a 46-kd ro/ss-a autoantigen gene that is the human homologue of the calcium-binding protein, calreticulin. the sequence of this 46-kd ro/ss-a protein (calreticulin) has significant homology to lambda ral-1, a recombinant cdna clone corresponding to a major antigen of the nematode, onchocerca volvulus, the infectious agent of onchocerciasis. we therefore sought to determine whether antibodies produced by onchocerciasis patients might crossreact with the human 46-kd ro ... | 1992 | 1602002 |
| characterization of a possible trna synthetase gene from onchocerca volvulus. | | 1992 | 1620168 |
| importance of migrants infected with onchocerca volvulus in west african river valleys protected by 14 to 15 years of simulium control. | a study was done to determine the importance of human migration from non-controlled endemic onchocerciasis foci to the river valleys that have been protected for the past 14 to 15 years by the vector control operations of the onchocerciasis control programme in west africa. the aim of the study was to assess the contribution of migrants to the prevalence and intensity of infection in villages from 5 major river valleys and their potential role in causing relapse of transmission once the vector i ... | 1991 | 1654591 |
| the reproductive lifespan of onchocerca volvulus in west african savanna. | the epidemiological model onchosim--a model and computer simulation program for the transmission and control of onchocerciasis--has been used to determine the range of plausible values for the reproductive lifespan of onchocerca volvulus. model predictions based on different lifespan quantifications were compared with the results of longitudinal skin-snip surveys undertaken in 4 reference villages during 13 to 14 years of successful vector control in the onchocerciasis control programme in west ... | 1991 | 1674401 |
| hallucinogenic and neuroleptic drug interactions with potential neurotransmitter receptors in parasitic nematodes. | receptors potentially involved in neurotransmitting have been characterised in the muscle tissue and in whole worms of the nematodes ascaris suum and onchocerca volvulus, respectively. binding studies revealed a high affinity for lsd with apparent kd values of 94 nm for a. suum and 120 nm for o. volvulus, whereas those of the neuroleptics haloperidol, spiperone and mianserin were found to be in the micromolar range. a variety of neurotransmitter antagonists, known to bind with high affinities ei ... | 1991 | 1674821 |
| identification of an onchocerca volvulus cdna encoding a low-molecular-weight antigen uniquely recognized by onchocerciasis patient sera. | the primary structure of an immunodominant antigen of the filarial parasite, onchocerca volvulus was deduced from cdna sequence analysis. using affinity-purified antibody from onchocerciasis patients from west africa, we have isolated a cdna clone from a lambda gt11 cdna expression library derived from microfilariae-producing female o. volvulus. the open reading frame encodes 152 amino acids, and the deduced sequence predicts a mr of 16,850 (consistent with the apparent mr of 18,000 of the immun ... | 1990 | 1689459 |
| an improved method of examining adult onchocerca volvulus worms. | adult onchocerca volvulus worms were extracted from alcohol-fixed nodules by collagenese digestion. the worms were stained in mayer's haematoxylin and brought up into glycerol. in this viscous fluid the stained and cleared worms could be unravelled in sequential lengths of 4-6 cm and mounted in glycerol on slides for longitudinal examination of their structure. the worm lengths were then cut into small pieces, 0.5 cm long, which were implanted sequentially into slits in a brick-shaped block of f ... | 1990 | 1692635 |
| many transcribed regions of the onchocerca volvulus genome contain the spliced leader sequence of caenorhabditis elegans. | genomic dnas of the related parasitic nematodes onchocerca volvulus and dirofilariae immitis, and a cdna library of o. volvulus, were examined for the presence of the 22-nucleotide spliced leader (sl) found at the 5' ends of 10 to 15% of the mrnas in the free-living nematode caenorhabditis elegans. as in c. elegans, genes for the sl rna are linked to the repetitive 5s rrna genes of o. volvulus and d. immitis, but unlike c. elegans, they are in the same orientation as the 5s rrna genes within the ... | 1990 | 1692960 |
| onchocerca volvulus: molecular cloning, primary structure, and expression of a microfilarial surface-associated antigen. | although the filarial nematode parasite onchocerca volvulus is an important human pathogen in large areas of africa and latin america, little is known of the molecular interactions that govern the clinical status of patients with this chronic, debilitating disease. as a step toward defining the parasite molecules important to the immunobiology of host-parasite interactions, we have identified and cloned a major surface-associated antigen expressed by o. volvulus microfilariae. radiolabeling expe ... | 1990 | 1695577 |
| the identification of an onchocerca-specific recombinant antigen containing a t cell epitope. | recombinant onchocerca volvulus ag have been derived from expression libraries and examined for their ability to stimulate pbmc from patients infected with o. volvulus. ten clones producing recombinant ag were selected and plaque purified; lysogens were produced and found to express beta-galactosidase fusion proteins ranging in molecular mass from 115 to 138 kda. when ammonium sulfate-precipitated lysates of these recombinant phage clones were examined for their ability to stimulate pbmc from a ... | 1990 | 1696601 |
| b cell responses to paramyosin. isotypic analysis and epitope mapping of filarial paramyosin in patients with onchocerciasis. | to examine the fine specificity of the human immune response to filarial paramyosin, the antigenicity of an expressed rcdna (2.55 kb) of dirofilaria immitis paramyosin was detailed by elisa. using sera from patients infected with onchocerca volvulus, we analyzed both the entire paramyosin molecule and six subcloned fragments for their igg, igg subclasses, and ige responses. patients from both guatemala (64% positive) and ghana (100% positive) reacted to paramyosin with specific igg levels above ... | 1990 | 1701001 |
| trypanosoma cruzi: a carbohydrate epitope defined by a monoclonal antibody as a possible marker of the acute phase of human chagas' disease. | an igm monoclonal antibody (mab) against a carbohydrate epitope present in trypanosoma cruzi trypomastigote excretory-secretory antigens and expressed by different developmental stages of the parasite (epimastigote, trypomastigote and intracellular amastigote) was linked to a solid phase matrix and used as an antigen-capture antibody. human serum complexes containing the epitope were then detected by using specific secondary antibodies against human immunoglobulin isotypes. results of detection ... | 1991 | 1715133 |
| ivermectin. a review of its antifilarial activity, pharmacokinetic properties and clinical efficacy in onchocerciasis. | ivermectin, a derivative of avermectin b, is an orally effective microfilaricidal agent. it is the current drug of choice for treating patients infected with the nematode onchocerca volvulus, which is a major cause of blindness in inhabitants of some tropical areas. ivermectin is administered orally as a single dose of 150 micrograms/kg given annually. skin and ocular microfilarial counts are dramatically reduced after the first dose, with some evidence for a resulting decrease in transmission o ... | 1991 | 1723366 |
| survival of onchocerca volvulus in nodules implanted in immunodeficient rodents. | onchocerca volvulus is an obligate human parasite, and its study has been difficult due to an inability to maintain it outside the human host. we report the successful transplantation of onchocercomata containing living adult o. volvulus worms into immunodeficient c.b.-17.scid/scid (scid) mice or athymic rnu/rnu (nude) rats. living, motile worms containing viable microfilariae were present in onchocercomata recovered from scid mice or nude rats for up to 20 wk, establishing a novel animal model ... | 1992 | 1738062 |
| comparison of the body wall myosin heavy chain sequences from onchocerca volvulus and brugia malayi. | the complete coding sequence of onchocerca volvulus myosin heavy chain has been determined from a series of overlapping cdnas. the protein sequences from the 2 filarids, one responsible for subcutaneous filariasis, the other for lymphatic filariasis, show 92% identity, and are 1957 amino acids long. each protein sequence is also equally related, with 75% identity, to mhc-b, the protein encoded by the unc-54 gene of the free-living nematode c.elegans. such analysis is useful in phylogenetic studi ... | 1992 | 1741012 |
| suppression of human lymphocyte responses to specific and non-specific stimuli in human onchocerciasis. | characterization of in vitro lymphocyte responsiveness was performed on selected groups of onchocerciasis patients from sudan and sierra leone. these patients manifested a very broad range of clinical signs and showed widely divergent parasite infection intensities. lymphocyte proliferative responses to soluble onchocerca volvulus antigen (sag) were poor in infected persons; mitogen and ppd responses were maintained in the normal range in one group of patients from southwestern sudan, but were p ... | 1991 | 1747951 |
| onchocerciasis in malawi. 1. prevalence, intensity and geographical distribution of onchocerca volvulus infection in the thyolo highlands. | skin snips from 23,373 persons living in the thyolo (formerly cholo) highlands focus of southern malawi showed infection with onchocerca volvulus to be unevenly distributed within the highland area. in the centre of the focus most adults were infected, though intensity of infection was light, not exceeding a geometric mean of 8 microfilariae per mg of skin. it was estimated that 327,000 persons live in areas where prevalence of infection exceeds 10% and, of these, 94,500 persons over the age of ... | 1991 | 1755058 |
| development of onchocerca volvulus microfilariae injected into simulium species from cameroon. | microfilariae (mff) of the savanna and forest strains of onchocerca volvulus (leuckart) were injected intrathoracically into adult females of simulium damnosum theobald sensu stricto, s.sirbanum vajime & dunbar, s.squamosum enderlein and s.mengense vajime & dunbar. nine days post infection (pi) 27-29% of the savanna mff and 31-38% of the forest strain had developed to third-stage larvae (l3), irrespective of the fly species, size or injection dose (5, 10 or 15 mff). savanna flies supported the d ... | 1991 | 1768922 |
| histochemical localization of gene expression in onchocerca volvulus: in situ dna histohybridization and immunocytochemistry. | we report here the development of in situ hybridization and immunohistochemistry protocols which permit the histological identification of gene expression of a cloned antigen of onchocerca volvulus, oi5, in the parasite. skin nodules containing female adult worms were fixed in a modified carnoy's fixative and embedded in paraffin. histological staining of tissue sections revealed uniformly excellent morphology and rna preservation. to localize mrna by in situ hybridization, tissue sections were ... | 1991 | 1775163 |
| characterization of an hsp70 gene from the human filarial parasite, brugia malayi (nematoda). | we have previously shown that an onchocerca volvulus cdna clone in lambda gt-11 designated ovg15, potentially encoding a peptide homologous to the 70-kda heat shock protein (hsp70), was recognized by sera of many individuals living in a zone endemic for lymphatic filariasis and most strikingly by sera from amicrofilaremic individuals including endemic normals, those with chronic symptoms and tpe patients. few asymptomatic microfilaremics recognized the hsp70. we have now used the insert from the ... | 1991 | 1775166 |
| translational elongation factor 1 alpha (ef-1 alpha) of onchocerca volvulus. | | 1991 | 1779985 |
| the effect of antimalarial chloroquine therapy and prophylaxis on concurrent infection with onchocerca volvulus in ecuador. | the effect of chloroquine phosphate on onchocerca volvulus in vivo was studied in ecuadorians undergoing treatment for malaria. all persons with a diagnosis of acute malaria and treated with 2500 mg of chloroquine over 3 d showed a 100% reduction of dermal o. volvulus microfilariae 7 d after treatment. however, 28 d after treatment the microfilarial densities returned to their pre-treatment levels and at 35 d they had increased to 121.6% of their pre-treatment values. treatment did not appear to ... | 1991 | 1780994 |
| human disease caused by dog heartworm. | pulmonary infection with d. immitis is an infrequently reported cause of lung disease in humans. approximately 80 cases have been reported in the united states, with increasing numbers reported in recent years. the largest single series from one institution is a series of 6 patients from ochsner clinic in new orleans, louisiana. although our series consisted of 3 females and no males, the disease is detected and diagnosed in males twice as often. the usual age range is 40 to 60 years. no case ha ... | 1991 | 1784039 |
| suramin and the time it takes to kill onchocerca volvulus. | the paper records the numbers of 1-2 mm shotty papules developing in the author's skin after 2-day courses of diethylcarbamazine (dec) repeated every 16 days before, during and after a 7.1 g suramin course for cutaneous onchocerciasis. assuming, from biopsy evidence, that each papule represented a dead onchocerca volvulus microfilaria (mf), the number of mfs reaching the skin every 16 days did not begin to fall until 96 days after the first full dose of suramin; and only reached zero by day 224. ... | 1991 | 1796231 |
| onchocerca volvulus: in vitro killing of microfilaria by neutrophils and eosinophils from experimentally infected chimpanzees. | peripheral blood leukocytes from chimpanzees experimentally infected with third stage larvae, or with nodular microfilaria (mf) of onchocerca volvulus, were evaluated for their ability to kill nodular mf in vitro. inoculation of chimpanzees with third stage larvae, and prospective follow up, permitted each animal to be classified as patent, infected but not patent, or post-patent. neither lymphocytes nor monocytes significantly adhered to, immobilized, or killed mf. however, neutrophils or eosin ... | 1991 | 1796232 |
| the chemotherapy of onchocerciasis. xv. studies with albendazole. | ninety-two males, infected with onchocerca volvulus, from an area of on-going transmission in the forest zone of southern ghana were treated with albendazole. 31 patients received 800 mg daily x 3, 31 received 1200 mg daily x 3 and 30 others received 800 mg daily x 7. albendazole was given as a single daily dose with a fatty breakfast. detailed systemic, ocular and laboratory examinations were performed pretreatment and at intervals over one year. nodules were extirpated on days 30 and 60 and ex ... | 1991 | 1796233 |
| immunohistological and electron microscopic studies of microfilariae in skin and lymph nodes from onchocerciasis patients after ivermectin treatment. | microfilariae were studied in skin and lymph node biopsies from liberian patients with generalised onchocerciasis 12-78 hours after administration of a single dose of 150 micrograms/kg body weight using histology, transmission electron microscopy and immunocytological staining with antibodies against an immunodominant antigen of onchocerca volvulus. most microfilariae in the skin appeared morphologically intact and beginning signs of degeneration were seen only on the ultrastructural level. the ... | 1991 | 1796234 |
| the embryogenesis of onchocerca volvulus over the first year after a single dose of ivermectin. | adult onchocerca volvulus, extracted from nodules before, and at intervals of two weeks to 12 months after, a single 150 micrograms/kg dose of ivermectin, were examined longitudinally and by sequential transverse sections. the mean number of male worms per nodule fell, and the proportion of nodules with no male worm rose, within two weeks of ivermectin and remained so for 12 months. in female worms, at intervals after ivermectin, the percentages of the length of the lower genital tracts occupied ... | 1991 | 1801140 |
| a temporary focus of savanna species of the simulium damnosum complex in the forest zone of liberia. | savanna species of the simulium damnosum complex, the major vectors of the blinding savanna type of onchocerciasis, were considered to be rare in liberia, until the dry season of 1988. in 1988 they became a serious nuisance, biting people at the bong iron ore mine within the rain forest zone. s. damnosum s.str. and s. sirbanum were found breeding, in association with s. adersi a non man-biting savanna species, in a stream emerging from the mine's tailings pond. the local forest species were extr ... | 1991 | 1801141 |
| immunity to onchocerca volvulus microfilariae in mice and the induction of cross-protection with o. lienalis. | inbred cba/ca mice were vaccinated with onchocerca volvulus or onchocerca lienalis microfilariae (mf) and challenged 100 days later with the homologous or heterologous parasite. there was a major reduction in mf recoveries from immunised animals compared with controls when the sensitising and challenge infections were both of o. volvulus mf. resistance was manifest within one week of challenge, and rose from an 87% reduction in recoveries on day 7 to a 96% reduction on day 15. similar results we ... | 1991 | 1801142 |
| onchocercacidal effect of three drug regimens of amocarzine in 148 patients of two races and both sexes from esmeraldas, ecuador. | the objective of this multidisciplinary clinical investigation was to test whether amocarzine was absorbed effectively and safely in patients of two races and either sex infected with onchocerca volvulus while living in the holoendemic area of esmeraldas province, ecuador. the prerequisite for a systemic onchocercacidal effect is the regular absorption of orally administered amocarzine. single dosing after overnight fasting proved to produce irregular absorption of amocarzine, although some micr ... | 1991 | 1801153 |
| influence of food related to dose on the pharmacokinetics of amocarzine and of its n-oxide metabolite, cgp 13 231, after oral administration to 20 onchocerciasis male patients from guatemala. | twenty male patients from guatemala infected with onchocerca volvulus received a 3 mg/kg oral dose of amocarzine twice daily for three days. the patients were randomly assigned to the sequence fasting/non-fasting and non-fasting/fasting for the morning administration on days 1 and 3. all other doses were given after food intake. blood samples on days 1 and 3 and urine fractions from days 3 to 5 were collected for the determination of the unchanged drug and of its n-oxide metabolite, cgp 13 231. ... | 1991 | 1801154 |
| concentrations of amocarzine in plasma of 71 ecuadorian patients of two different races receiving 3 mg/kg b.i.d. and 5 mg/kg o.d. oral postprandial doses for 3 days. | the possible influence of sex, race and of postprandial administration conditions (either immediately after the end of meal or one hour later) on the plasma concentrations of amocarzine and its n-oxide metabolite, cgp 13 231, was investigated. 71 ecuadorian patients (48 males and 23 females) of two different races (indio and negro) infected with onchocerca volvulus participated in the study. the concentrations were measured on day 3 at times 3 and 6 h after postprandial administration in the mor ... | 1991 | 1801155 |
| microfilaricidal effect of amocarzine in skin punch biopsies of patients with onchocerciasis from latin america. | skin punch biopsies were performed in 54 selected patients with onchocerciasis participating in a clinical trial with amocarzine (cgp 6140) in ecuador and guatemala. skin snipping for counting microfilariae of onchocerca volvulus was done before treatment (day 0) and day 4 and 8 following start of the therapy which consisted of 3 mg/kg amocarzine postprandially twice daily for three consecutive days. the mean microfilarial skin density has been reduced by 45% on day 4 and 95% on day 8. skin punc ... | 1991 | 1801156 |
| fine structure of microfilariae in the skin of onchocerciasis patients after exposure to amocarzine. | transmission electron microscopy was used to demonstrate the effects of amocarzine (cgp 6140) on the fine structure of onchocerca volvulus microfilariae (mf) in skin biopsies from patients treated orally in guatemala or transepidermally exposed in liberia. after 6-10 hours exposure to the drug most mf did not show any alterations and only a few mf contained increased numbers of vacuoles in the cytoplasm and clefts between cuticle and hypodermis. at 20-48 hours after treatment most of the mf show ... | 1991 | 1801159 |
| filariasis in gongola state nigeria. i: clinical and parasitological studies in mutum-biyu district. | a total of 2552 persons living in 9 villages along the benue river valley, mutum-biyu district of gongola state, nigeria were examined between october and december 1989 for filariasis. it is the first time a filariasis survey will be carried out in this state. 276 (10.8%) had wuchereria bancrofti, 50 (2.0%) had loa loa, 281 (11.0%) were positive for mansonella perstans while 12 (0.5%) were positive for onchocerca volvulus. villages located near the benue river had higher prevalence rates than th ... | 1991 | 1804869 |
| uptake of chloroquine by onchocerca volvulus in vivo and in vitro. | patients infected with onchocerca volvulus in the cayapa river focus in north-east ecuador were given 500 mg chloroquine diphosphate (cq) orally prior to nodulectomy. the concentrations of cq were determined in parasite fragments and host tissue dissected from the nodules, in skin overlying the nodules, and in plasma at 3, 4, 7, and 24 hours after dosing. onchocerca volvulus took up cq rapidly, in some cases accumulating the drug to concentrations of over 600 pmol mg-1 worm tissue by three hours ... | 1991 | 1809245 |
| immunoregulation in onchocerciasis. functional and phenotypic abnormalities of lymphocyte subsets and changes with therapy. | to help define the immunoregulatory defects in patients with onchocerciasis, flow cytometric analysis of circulating lymphocyte subpopulations was performed in parallel with functional assays. no significant differences in cd4/cd8 ratios were seen when microfilariae-positive individuals from guatemala were compared with guatemalan controls. however, the infected individuals had significantly increased numbers of circulating cd4+cd45ra+ lymphocytes (mean 38.3%) when compared with controls (mean 1 ... | 1991 | 1829096 |
| onchocerciasis in malawi. 2. subjective complaints and decreased weight in persons infected with onchocerca volvulus in the thyolo highlands. | in the course of an onchocerciasis survey in southern malawi, body weight was recorded for 10,335 persons aged 20 years and older, and the body mass index was calculated for 5572. a history of symptomatic complaints was elicited from 5653 persons 20 years of age and older. persons with microfilariae in the skin snips weighed significantly less than persons with negative skin snips. symptomatic complaints of musculoskeletal pains, itching, dizziness and poor vision were reported more commonly in ... | 1991 | 1836686 |
| molecular cloning and characterization of recombinant parasite antigens for immunodiagnosis of onchocerciasis. | immunological cross-reactivity among nematodes has hampered the development of specific serodiagnostic assays for onchocerciasis. in the present study, an onchocerca volvulus adult worm complementary dna expression library was differentially screened with human sera from patients infected with o. volvulus and with an omnibus anti-nematode serum pool comprised of sera from patients infected with brugia malayi, loa loa, wuchereria bancrofti, mansonella perstans, strongyloides stercoralis, ancylost ... | 1991 | 1840605 |
| [entomology of onchocerciasis in soconusco, chiapas, méxico. vii. quantitative variations in the transmission of onchocerca volvulus (nematoda: filaroiidea) according to human activity space]. | in this research we tried to demonstrate differences in transmission intensities of onchocerciasis by simulium ochraceum in the community of golondrinas, municipality of acacoyagua in the soconusco area of the state of chiapas. adult females of this species were captured in the center of the villages, the coffee plantation, and the corn bean planted plots, during 7 to 10 consecutive days of the months of june, august, november and december of 1983, and january, march, and may of 1984. captures w ... | 1991 | 1844134 |
| viability of adult onchocerca volvulus after six 2-weekly doses of ivermectin. | ivermectin is a safe, effective microfilaricide and microfilarial suppressant for onchocerca volvulus; but in single doses of 100-200 micrograms/kg body weight it has no macrofilaricidal action. the present trial aimed to determine whether 6 doses of 100 micrograms/kg ivermectin, given at 2-week intervals, would kill the adult worms. eighty-two nodules from 28 otherwise healthy adult male liberian patients treated with this ivermectin schedule, and 102 nodules from a similar group of 25 control ... | 1991 | 1860146 |
| partial characterization of 2-beta-mercaptoethanol-soluble surface-associated antigens of onchocerca volvulus. | antigens were extracted from the epicuticle/cuticle of intact female onchocerca volvulus using 2% 2-beta-mercaptoethanol and 1% sds. in western blot analysis a human infection serum selected for its high antibody titre against whole worm homogenates did not recognize any component solubilized by 1% sds. however, the same serum did bind at least 7 antigens among the material extracted with 2-beta-mercaptoethanol. these antigens have apparent molecular weights (mr) of: 15,000, 18,000, 28,000, 78,0 ... | 1991 | 1866191 |
| comparison of the effects of a single dose and of four six-monthly doses of ivermectin on adult onchocerca volvulus. | adult onchocerca volvulus worms, extracted from nodules of guatemalans by collagenase digestion, were examined whole and by histological techniques. one group of persons received a single 150 micrograms/kg dose of ivermectin; two other groups (one with older and one with younger nodules) received four similar doses of ivermectin at 6-month intervals. for each group, there were comparable untreated controls. all nodules were removed six months after the last dose. after a single dose, the only si ... | 1991 | 1867345 |
| [allergic granulomatous nodule of the conjunctiva disclosing onchocerciasis]. | a new case of conjunctival allergic nodule is reported in a guinean man. this lesion was first described by ashton and cook in 1979. histologically, this nodule consists of amorphous eosinophilic material surrounded by epithelioid and giant cells arranged in a pallisade; some eosinophils are often found in the inflammatory reaction. this lesion usually resolves spontaneously. in documented cases, nematodes and particularly filaria such as mansonella perstans are usually isolated. our observation ... | 1991 | 1880338 |
| hyperendemic onchocerciasis in the taraba river valley of gongola state (old adamawa province), nigeria. | a survey of the prevalence of onchocerciasis was carried out in the taraba river valley, nigeria where simulium damnosum s. l. is known to breed but about which no epidemiological data exists. skin biopsies taken from 2,876 persons in 14 communities were examined for the microfilariae of onchocerca volvulus. 100% infection rate was recorded in one of the communities, five other communities had prevalence rates between 81.0% and 94.7%. three communities had infection rates between 44.8% and 69.1% ... | 1991 | 1883152 |
| observations and reflections on the immature stages of onchocerca volvulus in the human host. | knowledge of the morphology, migrations and development rates of the l3, l4 and prepubertal l5 stages of onchocerca volvulus in the vertebrate host is an essential prerequisite to work vaccine development of chemoprophylaxis. after a brief review of the scanty literature available on this subject a description is given of two immature worms, one male and one female, found in an o. volvulus nodule from guatemala. the male, which measured 12 mm x 40 micron(s), had fine regular transverse cuticular ... | 1991 | 1888206 |
| surface area calculation for onchocerca volvulus microfilariae. | the pathogenesis of tissue damage in filarial infections involves the generation of inflammatory mediators by interaction of parasite surfaces with the host immune response. in the presence of a heavy parasite burden, the tremendous potential for development of adverse local or systemic inflammatory responses may be appreciated by knowledge of the cumulative surface area represented by circulating microfilariae. the approximate surface area of a single microfilariae of onchocerca volvulus was ca ... | 1991 | 1896774 |
| ivermectin uptake and distribution in the plasma and tissue of sudanese and mexican patients infected with onchocerca volvulus. | ten sudanese patients with onchocerca volvulus infection were treated with a single oral dose of 150 micrograms/kg of ivermectin. plasma samples were collected before treatment, 0.5, 1, 3, 4, 6, 12 hours and 1, 2, 3, 7, and 30 days. four patients were selected for nodulectomies and skin biopsies at 6, 18 and 30 hours and 3 days post treatment. using these samples o. volvulus worm fragments were dissected free of host nodular tissues for ivermectin extraction. ivermectin was present in the nodula ... | 1991 | 1896777 |
| ivermectin in the treatment of onchocerciasis in britain. | thirty-one patients with onchocerciasis were treated with a single dose of 150-200 micrograms/kg ivermectin. they were observed for three days to detect acute reactions and were reassessed clinically and parasitologically three, six and twelve months after treatment. 22 patients were expatriates. all had early, light and often localised infections and were not reexposed to infection during the course of the study. 25 patients completed follow-up. patients who relapsed were retreated with the sam ... | 1991 | 1896778 |
| onchocerca volvulus: characterization of monoclonal antibodies reactive with surface components of third-stage larvae. | five murine monoclonal antibodies (mab's) have been produced which are reactive with the surface of the third-stage larvae (l3) of onchocerca volvulus. these were produced from a fusion performed after intrasplenic injection of 10 live o. volvulus l3. hybridomas were first screened by elisa using a pbs extract of o. volvulus female adult worms. elisa negative wells were screened by ifa on whole formalin-fixed l3. five mab's were isolated which were reactive with the surface of l3, all were found ... | 1991 | 1896779 |
| onchocerca volvulus: application of the polymerase chain reaction to identification and strain differentiation of the parasite. | previous studies have demonstrated that the genome of onchocerca volvulus contains a variable tandemly repeated dna sequence family with a unit length of 150 bp. the variability of the 150-bp family has been exploited to develop o. volvulus strain and species specific dna probes. application of these dna probes to the study of the epidemiologically most significant life cycle stages of the parasite has been confounded by several obstacles. these include the relative insensitivity of some of the ... | 1991 | 1915748 |
| characterization of the autoantigen calreticulin. | anti-ro/ss-a antibodies are commonly found in the sera of patients with sjögren's syndrome and sle. these antibodies also occur in the mothers of children with neonatal lupus and congenital heart block. ro/ss-a is a ribonucleoprotein complex whose cellular function remains unknown. to study its cellular function and to characterize its immunoreactivity, we have used an oligonucleotide designed after the published amino terminal sequence of a putative 60-kda ro/ss-a autoantigen to isolate its cdn ... | 1991 | 1919005 |
| cdna clones of onchocerca volvulus low molecular weight antigens provide immunologically specific diagnostic probes. | we report here a panel of cdna clones from onchocerca volvulus which were isolated on the basis of being uniquely recognised by onchocerciasis sera and not by sera from patients infected with the major lymphatic filarial nematode parasite wuchereria bancrofti. over 90% of o. volvulus recombinants from a primary screen were found to cross-react with lymphatic filariasis sera and were discarded. the subset of specific clones, selected with pooled sera, was then screened with panels of individual p ... | 1991 | 1922197 |
| morphological demonstration of essential functional changes after in vitro and in vivo transition of infective onchocerca volvulus to the post-infective stage. | transmission electron microscopic investigation of the morphogenesis of onchocerca volvulus through the third moult to the post-infective stage revealed essential alterations in various larval organs. complete rebuilding of surface structures, the reduction of secretory granules in the glandular oesophagus, the unfolding of the intestine, an increase in the number of nerve fibres in the nerve ring and novel sensory papillae were significant findings. transition from third- to fourth-stage larvae ... | 1991 | 1924261 |