| homologous and distinctive antigens of onchocerca volvulus and dirofilaria immitis: detection by an enzyme-linked immuno-inhibition assay. | the limited accessibility of specimens of onchocerca volvulus has hampered investigations of factors that determine the clinical course of infection of man by this filarial nematode. parasites antigenically related to o. volvulus have been variously proposed as alternative sources of test antigens. the present study has utilized serologic methods to probe the degree of identity of the antigenic constituents of o. volvulus and dirofilaria immitis, the dog heartworm. 35s-methionine-labeled protein ... | 1984 | 6736653 |
| clinical trials of amodiaquine in onchocerciasis. | twenty onchocerciasis patients from the rain-forest zone of western nigeria were treated with amodiaquine in total dosages ranging from 22 to 68 mg/kg of body weight given over 2-9 days. there was no activity against either the microfilariae or adult forms of onchocerca volvulus. it is concluded that the drug, which was poorly tolerated by 12 patients, is ineffective against human onchocerciasis. | 1982 | 6761007 |
| filariasis in amerindians of western guyana with observations on transmission of mansonella ozzardi by a simulium species of the amazonicum group. | in order to conduct experimental infection studies of mansonella ozzardi in local haematophagous diptera, volunteers infected with this parasite were identified during a microfilaria survey in four amerindian villages in the pakaraima mountains of western guyana, near the brazilian border. m. ozzardi microfilariae were detected in thick blood smears from 8-21% of persons examined. they were also found in skin snips from 8/73 persons all of whom were positive by blood smear examination. no onchoc ... | 1982 | 6761913 |
| detection of circulating antigens in onchocerciasis. | this report describes the presence of circulating onchocerca volvulus antigens (coa) in sera of patients with onchocerciasis. by using a double diffusion immunoelectrophoresis method, coa could be detected in 24 of 77 sera analyzed (31%). in contrast, when more sensitive assays such as the radioimmunoprecipitation-peg assay or sandwich radioimmunoassay were used to detect coa, about 75% of the sera from o. volvulus-infected patients were found positive; moreover, a highly significant correlation ... | 1981 | 6798890 |
| a diagnostic skin test for onchocerca volvulus infection. | onchocerca supernatant (os) was prepared by a technique permitting live microfilariae to migrate from nodule tissue through agar gel into sterile hanks balanced salt/penicillin-streptomycin solution where they metabolized. the os, after dialysis, was passed through seitz viral filter and either concentrated or lyophilized. using rabbit antiserum in immunodiffusion and immunoelectrophoresis tests, microfilariae proteins and also human protein were detected in out os. no common antigens were found ... | 1981 | 6808726 |
| sowda--onchocerciasis in north yemen: a clinicopathologic study of 18 patients. | sowda is an unusual form of onchocerciasis in yemenites that differs from african onchocerciasis. clinical and pathological studies were performed on 18 patients in yemen arab republic (north yemen). biopsies of skin and lymph nodes were taken, and then processed at the armed forces institute of pathology, washington, d.c. the most striking clinical features were swollen, darkened, pruritic, papular skin changes that were usually limited to one leg, more rarely to one arm, and large soft regiona ... | 1983 | 6824118 |
| ocular and systemic complications of diethylcarbamazine therapy for onchocerciasis: association with circulating immune complexes. | diethylcarbamazine (dec) therapy for onchocerca volvulus infection results in frequent ocular and systemic complications, but the pathogenesis of these complications is unclear. twenty men with o. volvulus infection were treated over a period of six months with dec given daily for one week and weekly thereafter. major systemic and ocular complications included proteinuria, severe pruritus, visual field constriction, optic nerve pallor, chorioretinitis, anterior uveitis, and punctate keratitis. l ... | 1983 | 6842023 |
| chemotaxis of human granulocytes toward microfilariae of onchocerca volvulus. | migration of human peripheral blood granulocytes in response to microfilariae of o. volvulus was demonstrated using modified boyden chambers. granulocyte migration was significantly enhanced when microfilariae were preincubated with heat-inactivated immune serum (delta is), then added to a fresh serum source (p less than 0.025). this effect was not seen when microfilariae were incubated in medium alone, in delta is alone, in delta is plus c4-deficient guinea-pig serum, or in fresh serum alone. t ... | 1983 | 6844030 |
| the fine structure of adult onchocerca volvulus. iii. the cuticle, the interchordal hypodermis and the muscle cells of the female worm. | the morphology of the cuticle, the interchordal hypodermis and the muscle cells of three mature but not full-grown worms, one worm less than five years old, two worms at least five years old and seven worms of unknown age are described. the cuticle in the anterior region is very similar to that of the male worm, however, in the midbody region the cuticular structure is more simple. the length of the folds of the surface membrane and the thickness of the coat vary considerably. the outer surface ... | 1983 | 6845417 |
| onchocerca volvulus: detection of circulating antigen by monoclonal antibodies in human onchocerciasis. | a monoclonal antibody of the igm class recognizing onchocerca volvulus circulating antigen (coa) was obtained. this monoclonal antibody was used in a radioimmunoprecipitation-peg assay (ripega) to detect circulating antigen in onchocerciasis patients' sera. coa could be detected in 63 (80%) of the 79 african patient sera tested, and in 126 (76%) of the 164 indian (venezuela) sera studied. there was no direct correlation between the presence of coa detected in the patient serum and the level of m ... | 1983 | 6859399 |
| non-specific suppression of antigen-induced lymphocyte blastogenesis in onchocerca volvulus infection in man. | lymphocyte blastogenic responses to o. volvulus antigen (oncho ag), sksd, and the mitogen pha were tested in three groups of persons: light to moderately infected persons (inf); previously exposed but uninfected persons (exp) and normal controls (nc). the exposed group showed significant responsiveness to oncho ag (delta ct/min = 6,002 +/- 1,375), while the infected (delta ct/min = 943 +/- 418) and normal control (delta ct/min = 428 +/- 418) groups did not. the mean blastogenic response to sksd ... | 1983 | 6861374 |
| [lymphographic and morphological studies of the conjunctiva in onchocerciasis patients in liberia]. | conjunctival lymphographies in patients infected with onchocerca volvulus in liberia showed normal or only slightly dilated lymphatics. the light-microscopical studies of conjunctival specimens revealed microfilariae predominantly in edematous dilated interstitial channels. microfilariae in lymphatics and interstitial channels without endothelium of the conjunctivae were demonstrated by scanning and transmission electron microscopy. no signs of inflammatory cellular reaction were found in the vi ... | 1983 | 6865255 |
| production of onchocerca volvulus infective larvae from cryopreserved microfilariae in a surrogate vector. | | 1983 | 6868119 |
| circulating immune complexes and their possible relevance to other immunological parameters in guatemalan onchocerciasis. | circulating immune complexes (cic) were demonstrated in sera of guatemalan patients with onchocerciasis by raji cell radioimmunoassay. 44% of patients but none of controls had abnormally high concentrations of cic in their sera. the increased concentrations of cic were found more frequently in patients with lower density of microfilariae in their skin biopsies. patients with higher concentrations of cic appeared to have increased titers of serum antibodies to onchocerca volvulus. a depression of ... | 1983 | 6874107 |
| acid phosphatase patterns in microfilariae of onchocerca volvulus s.l. from the upper orinoco basin, venezuela. | the patterns of acid phosphatase in strains of onchocerca volvulus s.l. which parasitize an amerindian population (yanomami) in venezuela's upper orinoco basin were examined by using the naphthol as-tr phosphate method. the study sample consisted of 40 yanomami inhabiting a savannah area at 950 m above sea level and 21 yanomami residents of a tropical rainforest area at an altitude of 250 m. stained intrauterine microfilariae, still within the egg case, exhibited a diffuse distribution of the en ... | 1983 | 6879704 |
| development of onchocerca volvulus from cryopreserved microfilariae in three temperate species of laboratory-reared blackflies. | three species of british blackflies, simulium ornatum s.l., s. erythrocephalum and s. lineatum, were infected with the cryopreserved microfilariae of onchocerca volvulus obtained from human skin-snips in the sudan. doses of 5 or 10 microfilariae per fly were administered by intrathoracic injection into females, 1-2 days after eclosion from pupae. after 7 days at 27.5 degrees c and 85% relative humidity, microfilariae had completed development to third-stage larvae. fly survival rates were highes ... | 1983 | 6879707 |
| diagnosis of onchocerca volvulus infection in guatemalan children. | nodule examination, the mazzotti test (a provocative challenge with diethylcarbamazine), and the enzyme-linked immunosorbent assay (elisa) were compared for diagnostic efficacy in children who were born in an area endemic for onchocerciasis in guatemala and were skin-biopsy negative for microfilaria of onchocerca volvulus. four groups of children under 16 years of age were formed based upon the possible combinations of nodule positivity or negativity and elisa positivity or negativity. only thos ... | 1983 | 6881422 |
| onchocerciasis in guatemala. epidemiology in fincas with various intensities of infection. | to provide quantitative information on the epidemiology of infection with onchocerca volvulus and to define the association between indicators of infection and onchocercal eye disease, skin snips were obtained and skin and ocular examinations were performed on 892 persons living on seven guatemalan coffee plantations. skin-snip positivity and the density of microfilariae in the skin increased with age, reaching highest levels at 15-19 years, and both were greater in males than females. a history ... | 1981 | 6974510 |
| the chemotherapy of onchocerciasis iv. further trials with metrifonate. | thirty-four healthy adult males, moderately to heavily infected with onchocerca volvulus, were treated daily with metrifonate at 10 mg/kg body weight for either three or six days. the patients' reactions and the effects on the microfilariae were measured on a 'single-blind' basis. muscarinic effects of acetylcholine were prominent despite the use of belladonna alkaloids, and nicotinic effects--leading to a proximal muscle weakness--occurred in one patient after the fifth dose. a syndrome of poly ... | 1980 | 6994665 |
| studies on bancroftian filariasis in liberia, west africa. iv. notes on side effects observed during a diethylcarbamazine treatment campaign in a rural area endemic for wuchereria bancrofti and onchocerca volvulus. | 464 persons of whom 189 proved to be infected with microfilariae of wuchereria bancrofti and/or onchocerca volvulus were examined for adverse reactions due to diethylcarbamazine, which was administered during a filariasis control campaign. persons older than 20 years of age were significantly more affected than younger persons and men showed distinctly more side effects than women. the most frequent complaints were skin reactions followed by gastrointestinal complications. the significantly high ... | 1980 | 7003853 |
| serologic studies on onchocerciasis in guatemala using fixed-tissue sections of adult onchocerca volvulus. | sera from 458 residents of a coffee plantation in an area of guatemala endemic for onchocerciasis were examined for the presence of antibodies to onchocerca volvulus using a fluorescent antibody (ifa) test with sections of adult worms as the antigen. antibody response increased with age of the residents and microfilarial density. a total of 70.0% of the residents were serologically positive and 65.1% were positive for microfilariae. males had higher microfilarial densities and higher ifa respons ... | 1980 | 7004218 |
| [serodiagnosis of onchocerciasis using micro-elisa. study of 450 sera and comparison with indirect immunofluorescence]. | the microtest elisa has been used for human onchocerciasis serological study. the antigens employed were adult onchocerca volvulus extracts, collected from dissected nodules, delipidized and cleared from human proteins by affinity chromatography. under the circumstances, the positivity limit of the test seems excellent (maximum )d: 0,23) defined with 171 negative sera, 66 of them taken from africans. specificity controls were studied with 56 heterologous sera; cross-reactions occurred with hydat ... | 1980 | 7006842 |
| simulium species of the amazonicum group as vectors of mansonella ozzardi in the brazilian amazon. | experimental infection with mansonella ozzardi of common haematophagous diptera collected at a ticuna indian village on the upper reaches of the solimões river in the brazilian amazon, showed that simulium amazonicum and simulium n.sp. are capable of supporting full development of the parasite. natural infections with this filaria were found in both species including infective larvae in simulium n.sp. no development of m. ozzardi occurred in mansonia amazonensis, culicoides insinuatus or lepisel ... | 1980 | 7010699 |
| a review of simulium damnosum s.l. and human onchocerciasis in nigeria, with special reference to geographical distribution and the development of a nigerian national control campaign. | the confirmed geographical distribution of human onchocerciasis and its simulium damnosum complex vectors in nigeria is reviewed with the aim of defining the endemic zones of the disease relevant to the planning of a nigerian national onchocerciasis control campaign. five major endemic zones are recognized, a terminology suggested for them, their sizes estimated and the disease and vector situation within each zone briefly described; four of the zones are in savanna areas of the north, and the f ... | 1981 | 7015637 |
| associations in filarial infections in man in the savanna zones of mali and upper volta. | in 14 villages located in the west african savanna belt, 1,305 people were examined for microfilariae in blood and skin. the results indicate that the associations between filariae in infected patients are not the result of chance alone. the frequency of associations between wuchereria bancrofti and tetrapetalonema perstans was highly significant, whereas onchocerca volvulus appeared to be associated with w. bancrofti only in the absence of t. perstans. | 1981 | 7020450 |
| ocular changes with oral and transepidermal diethylcarbamazine therapy of onchocerciasis. | twenty men with moderate infection of onchocerca volvulus were studied in a double-masked, controlled clinical trial to compare the safety and efficacy of oral diethylcarbamazine (dec) with topical dec lotion. visual acuity and colour vision did not alter during the 6 months of observation, although 2 patients receiving dec lotion and 3 patients receiving oral dec developed either visual field constriction or optic atrophy. fluffy corneal opacities were common in both groups. intraocular microfi ... | 1981 | 7020746 |
| which cytospecies of the simulium damnosum complex did blacklock incriminate in the transmission of onchocerca volvulus? | | 1981 | 7032433 |
| further trials of mebendazole and metrifonate in the treatment of onchocerciasis. | in clinical drug trials, mebendazole, given in various daily doses for up to 14 days to a maximum total of 16.8 g, was found to be ineffective against both adult onchocerca volvulus and the microfilariae. metrifonate, however, given in doses of 100 mg daily for 14 days or as four doses of 10 mg/kg of body weight either on alternate days or at weekly intervals showed moderate activity against the microfilariae but none against the adult worm. | 1982 | 7044588 |
| early formation of the nodule in guatemalan onchocerciasis. | thirty-eight nodules containing adults of onchocerca volvulus were removed from 36 patients who had no detectable microfilariae in skin snips. worms were digested from nodules in collagenase solution, maintained alive in vitro, and the number, sex, and state of fecundity were recorded. a total of 48 female and 8 male worms were recovered; 39 females were in the nodules without the presence of a male. eleven females (22.9%) had microfilariae in utero or produced microfilariae in vitro; seven of t ... | 1982 | 7072889 |
| effects of temperature on development of onchocerca volvulus in simulium ochraceum, and longevity of the simuliid vector. | the effects of temperature on the development of onchocerca volvulus in simulium ochraceum, and on the vector's longevity were studied under simulated environmental conditions in the laboratory. when s. ochraceum (which had fed on a person infected with o. volvulus) were maintained at different, constant temperatures (10-30 c), larvae developed to the infective stage between 20 and 28 c. the time required for development to the infective stage depended on the relationship of y = -0.3760 + 0.0222 ... | 1982 | 7097444 |
| controlled studies on the effect of nodulectomy on the concentration of microfilariae in the skin of patients exposed o continuing transmission of onchocerca volvulus in the rain-forest zone of western nigeria. | two sets of controlled experiments were conducted, using 13 adult onchocerciasis patients from a village in the hyperendemic rain-forest zone of western nigeria, to determine the effect of the excision of one or two onchocercal nodules on the concentration of microfilariae in the skin. the results show that, in patients with established infections who are exposed to continuing reinfection, nodulectomy per se does not reduce the microfilarial density, overall or in the same anatomical region from ... | 1982 | 7101441 |
| studies on the concentration of onchocerca volvulus microfilariae in the skin in relation to the nodule. | the concentration of microfilariae in the skin over and at distance sup to 10 cm from the onchocercal nodule was studied in eight patients with established onchocerciasis. in spite of wide variations in microfilarial counts from snips taken from the same patient no significant differences were found in respect of distance or direction from the nodule. it is concluded that microfilariae are uniformly distributed in the skin around and onchocercal nodule in established infections. | 1982 | 7101442 |
| the fine structure of adult onchocerca volvulus. i. the cuticle, the hypodermis and the muscle cell of the male worm. | the fine structure of the cuticle, the hypodermis and the muscle cells of five male worms from liberia and of two male worms, at least five years old, from upper volta is described. the cuticle in the lateral regions is thicker and consists of more layers than in the dorsal and ventral regions. the innermost zone of the hypodermis contains a wide labyrinth of extracellular clefts. the muscle cells are of the shallow coelomyarian type. bacteria were found in the hypodermis of worms from liberia a ... | 1982 | 7112683 |
| the fine structure of adult onchocerca volvulus. ii. the intestine and the reproductive system of the male worm. | the morphology of the gut and the genital duct of five male worms from liberia and two male worms at least five years old, from upper volta are described. the lumen of the intestine can be distended vesicularly or it can be reduced to a cleft which is filled with microvilli. the intestinal epithelium contains concentric spherules or dense bodies with piles of lamellae. in parts of the intestine of a live worm the cells can be completely disintegrated. the wall of the testis consists of a squamou ... | 1982 | 7135474 |
| anthropophily of simulium damnosum s.l. and its rôle as a vector of human onchocerciasis in the yemen arab republic. | immature stages of simulium damnosum s.l. were collected in four of the main wadis (surdud, zabid, rasyan, ghayl) which drain westward to the red sea. the species was absent from the wadi tuban which flows to the south-east, but other black-fly species were found herein. for the first time it was shown that s. damnosum s.l. in the yemen bites man, may ingest microfilariae of onchocerca volvulus and can harbour filarial infections. out of 303 flies which were caught on human bait in the wadi rasy ... | 1982 | 7135475 |
| theoretical approach to the epidemiology of onchocerciasis in guatemala. | the data collected by the onchocerciasis research and control project in guatemala were theoretically analyzed. first, muench's simple catalytic model was applied to the age distribution of the microfilaria-positive rate in each village to obtain the force of infection. the intensity of infection, expressed by force of infection, with onchocerca volvulus in humans of individual villages was found to be clearly associated with the distribution and abundance of the vector, simulium ochraceum. by c ... | 1982 | 7154408 |
| a method for determining the concentration of onchocerca volvulus microfilariae in urine. | | 1982 | 7166634 |
| prevalence of onchocerciasis in ile-ire district, (ifelodun), kwara state, nigeria. | a survey to determine the prevalence of onchocerciasis was carried out in the ile-ire district of kwara state, nigeria between april 1979 and may 1980. of the 4436 subjects examined, 63% were positive for microfilariae of onchocerca volvulus in their skin snips and 51% of these had palpable onchocercal nodules. the infection rate was 40% among those under 10 years of age; the rate was significantly higher (75%) among the older subjects. there was no difference in the prevalence of infection betw ... | 1982 | 7179463 |
| electron microscope study of the cuticle of male and female onchocerca volvulus from various geographic areas. | male and female onchocerca volvulus from liberia, upper volta, tanzania and guatemala were examined by scanning and by transmission electron microscopy. in the cuticle of the female a basal, a median and a cortical layer can be differentiated. the outer limitation of the cuticle is an irregularly folded surface membrane. excluding the anterior region the entire cuticle of the worm is covered by a coat. a regular fine honey-comb structure of the surface is found in the anterior region of the fema ... | 1980 | 7191154 |
| ige antibodies are more species-specific than igg antibodies in human onchocerciasis and lymphatic filariasis. | to explore the relative species specificities of the ige and igg antibody responses to helminth infections in man, we studied four pools of sera from patients infected with wuchereria bancrofti, brugia malayi, onchocerca volvulus or ascaris lumbricoides and ten individual sera from patients with onchocerciasis. ige antibodies were detected by radioallergosorbent test (rast) analysis and igg antibodies by a staphylococcus protein a radioimmunoassay (staph a-ria). analysis of the binding curves wi ... | 1982 | 7199027 |
| quantitative aspects of the infection of simulium ochraceum by onchocerca volvulus: the relation of skin microfilarial density to vector infection. | in guatemala, 16 wild simulium ochraceum were permitted to feed on a 15" x 15" grid on the back of each of 13 persons infected with onchocerca volvulus. based on 6 skin biopsies, the mean microfilarial density (mfd) in these study participants ranged from 1.256 mf/mg of skin to 111.824 mf/mg. the files were dissected 6 to 10 hours after feeding and the number of microfilariae in the blood meal and escaping the midgut into the thoracic musculature were counted. a nearly linear relationship was fo ... | 1980 | 7233543 |
| failure of furazolidone in the treatment of onchocerciasis. | 12 adult onchocerciasis patients from the rain forest zone of nigeria were treated with furazolidone in divided daily doses ranging from 5--15 mg per kg body weight for 7--21 days to a maximum total dose of 6.3 g. the drug showed neither micro- nor macrofilaricidal activity against onchocerca volvulus. | 1981 | 7233548 |
| [simulium albivirgulatum wanson et henrard, 1944, vector of onchocerca volvulus, in the central basin region of zaire. preliminary note]. | | 1980 | 7247516 |
| the use of aceto-orcein-stained squash preparations for enumeration of nuclei in microfilariae of various filarial parasites. | the nuclear numbers of situated between the cephalic space and the nerve ring (cs-nr) in the microfilariae of six filarial species were examined. for the counting of nuclei, aceto-orcein squashing preparations were used. this procedure revealed nuclei clearly visible under the phase-contrast microscope. the mean number of nuclei in the cs-nr region was very similar between brugia pahangi and b. malayi, but was statistically different between onchocerca volvulus and o. gutturosa. in the microfila ... | 1981 | 7258480 |
| the effect of drug treatment on the pattern of emergence of onchocerca volvulus microfilariae from skin snips. | a controlled study was carried out to determine the effect of some known anti-filarial drugs on the pattern of emergence of onchocerca volvulus microfilariae from skin snips into saline. the results show that before treatment, 81.7 to 92.1% of microfilariae emerge in all the groups within 24 hours. the differences between the groups were not significant. after treatment with oral diethylcarbamazine, metrifonate and topical diethylcarbamazine (dec) the percentage of microfilariae emerging from th ... | 1981 | 7264274 |
| scanning electron microscope studies on the anterior region of the larvae of onchocerca volvulus in the vector. | | 1981 | 7268848 |
| limited fly load and development of onchocerca volvulus microfilariae in guatemalan simulium ochraceum. | fly load of onchocerca volvulus microfilariae and their early development in simulium ochraceum were examined at intervals of 10, 30 and 60 min after ingestion and then hourly up to 72 hours. many microfilariae ingested were damaged by the cibarial armature of the vector, limiting the fly load, but some of these damaged microfilariae were able to penetrate the gut before they died. thus, the mean number of the living parasites per fly in the head and thorax decreased gradually with elapse of tim ... | 1981 | 7276505 |
| cellular killing of microfilariae of onchocerca volvulus: eosinophil and neutrophil-mediated immune serum-dependent destruction. | | 1981 | 7276574 |
| seasonal occurrence of simulium ochraceum, the principal vector of onchocerca volvulus in the southeastern endemic area of guatemala. | investigation of the seasonal occurrence of simulium ochraceum, the principal vector of the guatemalan strain of onchocerca volvulus, were made from august 1978 until january 1980 in the upper reaches of the two main rivers of endemic onchocerciasis in escuintla, guatemala. the results showed that in the late dry season s. ochraceum larvae were restricted to permanent streams at intermediate altitudes. during the rainy season, though, the preimaginal sites of this black fly extended to the upper ... | 1981 | 7283010 |
| [transmission of onchocerca volvulus by simulium albivirgulatum in the endemic area for onchocercosis of the central basin, zaire]. | | 1981 | 7283500 |
| [paraclinical study of onchocercosis in a leprous and non-leprous population]. | in a survey dealing with the frequency of onchocerciasis in leprous environments in the marchoux institute in bamako (mali) evidence is given that 43% of the leprous persons hospitalized there were touched in addition by onchocerciasis whereas, only 14% of the consultants in dermatology have proved to be also onchocercian. this last frequency is consistent with the overall estimation usually recognized for mali. no difference was shown between leprous and non-leprous persons for snip. in contras ... | 1981 | 7285265 |
| transplantation of adult onchocerca volvulus into chimpanzees. | | 1981 | 7303143 |
| inhibition of nadp-linked malic enzyme from onchocerca volvulus and dirofilaria immitis by suramin. | nadp-linked malic enzyme (malate dehydrogenase (oxaloacetate-decarboxylating) nadp+, ec 1.1.1.40) has been partially purified from adult onchocerca volvulus and dirofilaria immitis. suramin was found to inhibit the activity of malic enzyme from both filarial worms. the inhibition constants for suramin were calculated to be 0.011 microm and 0.015 microm for the enzymes from o. volvulus and d. immitis, respectively. in the case of nadp-linked malic enzyme from trypanosoma brucei and chicken liver ... | 1981 | 7322187 |
| retinol, onchocerciasis and onchocerca volvulus. | | 1981 | 7324149 |
| seasonal variation in the microfilarial skin density of onchocerca volvulus and in the biting activity of simulium spp. in guatemala. | the density of onchocerca volvulus microfilariae in the skin of 11 carriers was examined by carrying out a monthly examination in a single endemic area of guatemalan onchocerciasis. the results obtained suggested the possibility of a seasonal variation in the microfilarial skin density. almost all of the volunteers participating had shown a peak concentration of microfilariae in september, followed by august or october. the highest biting densities of simulium ochraceum, the principal vector of ... | 1981 | 7330946 |
| studies of metrifonate in onchocerciasis. | metrifonate has been studied in the treatment of infections with onchocerca volvulus in west africa. in doses of 10 mg/kg daily for six days, metrifonate was effective against the microfilariae but produced unpleasant reactions due both to the death of the microfilariae and to the muscarinic effects of the drug. in a comparison of 10 mg/kg metrifonate, for 3 doses at 10 day intervals, with diethylcarbamazine (d.e.c.) in a total dose of 6.6 g, metrifonate was significantly less effective than d.e ... | 1981 | 7344407 |
| onchocerciasis diagnosis and the probability of visual loss in patients with skin snips negative for onchocerca volvulus microfilariae. | two methods have been used to verify the diagnosis of patients living in the onchocerciasis hyperendemic region of liberia found to have o.v. negative skin snips. the first was based on a histological and an electronmicroscopic examination of the skin to determine whether the characteristic onchocerciasis dermatitis was absent, and to compare the results with age matched subjects having minimal to densely o.v. mf infested skin. the second method involved the skin response of patients with o.v. m ... | 1981 | 7345681 |
| parasitological diagnosis of onchocerciasis: comparisons of incubation media and incubation times for skin snips. | tissue culture fluid nctc 135 (hank's base) was compared to water and to saline as incubation media for the detection of microfilariae of onchocerca volvulus in skin snips. nctc 135 allowed detection of significantly more positive persons than did water (p less than 0.001) or saline (p less than 0.05) when two snips per person were incubated for periods of 0.5 or 24 hours. in addition, snips containing microfilariae were incubated in nctc 135 or in saline and the number of emerged microfilariae ... | 1980 | 7352625 |
| analysis of the anticomplementary activity in sera of three african patients with parasitic and bacteriological infections. | the sera of three different patients from togo, africa were investigated with respect to their complement profile. the three patients were suffering from parasitic (onchocerca volvulus) and bacteriological (treponema pertenue) diseases. the total hemolytic activity (50% hemolytic complement) was markedly depressed. the analysis of the individual complement components revealed the the titers of c1, c2, c3, and c4 were lowered up to 90%, indicating an activation of the classical pathway of complem ... | 1980 | 7358423 |
| scanning electron microscope study of infective filaria larvae of type d and onchocerca volvulus. | | 1980 | 7376249 |
| investigations on female onchocerca volvulus for the evaluation of drug trials. | females of o. volvulus show several typical morphological alterations during their ontogenesis. in order not to attribute such natural findings to the efficacy of drugs in drug trials female worms isolated from untreated patients in liberia and togo were examined by light microscopy. local incrustations could be found regularly on the surface of the female parasite. different inclusions are described which could often be found. they partially lead to degeneration and calcification. for the evalu ... | 1980 | 7376250 |
| observations on onchocerca volvulus in experimentally infected chimpanzees. | the paper describes observations made on 32 chimpanzees experimentally infected with onchocerca volvulus. the mean pre-patent intervals for the cameroon forest and the guatemalan strains of o. volvulus were 13-16 months and 12-15 months respectively. that for the cameroon sudan-savanna strain was much longer, i.e. 22-23 months. the numbers of microfilariae found in the skins of animals infected with the cameroon sudan-savanna strain were also much lower than in animals infected with the other tw ... | 1980 | 7376251 |
| onchocerca volvulus: effect of suramin on lactate dehydrogenase and malate dehydrogenase. | lactate dehydrogenase and malate dehydrogenases were partially purified and characterized from adult o. volvulus. the molecular weight of lactate dehydrogenase was determined to be 130 000, those of malate dehydrogenase i and ii to be 120 000 and 65 000, respectively. the activities of both malate dehydrogenases and of the lactate dehydrogenase were strongly inhibited by suramin. the inhibition constants were determined to be in the range of 2 microm to 5 microm. the type of inhibition was found ... | 1980 | 7376252 |
| the 'in vitro' effect of diethylcarbamazine on the motility and survival of onchocerca volvulus microfilariae. | | 1980 | 7376253 |
| circulating immune complexes in onchocerciasis. | circulating immune complexes were detected in sera of patients with both localized and generalized onchocerciasis by a 125i-clq binding assay but not by the igg latex agglutination inhibition method. gel filtration of sera demonstrated high molecular weight clq-reactive material(greater than 2 x 10(6) daltons) which contained igm but no igg. antibody titres to onchocerca volvulus antigen were higher in patients with generalized disease than in those with the localized form. the lack of correlati ... | 1980 | 7379329 |
| simulium exiguum, the vector of onchocerca volvulus on the rio micay, colombia. | simulium exiguum were collected in the san antonio area on the rio micay as they blood-fed on a volunteer naturally infected with onchocerca volvulus. the daily dissection of specimens revealed that delayed larval development was common and 23% of the larvae were abnormally formed. however, third-stage larvae were recovered by late day 5 (140 hours) following engorgement. it is concluded that s. exiguum is the vector of o. volvulus at this colombian endemic focus even though its host efficiency ... | 1980 | 7386717 |
| living larva of onchocerca volvulus. | | 1980 | 7387956 |
| [river blindness, infection by the filaria onchocerca volvulus]. | | 1980 | 7409714 |
| analysis of enzymatically isolated adults of onchocerca volvulus after treatment of patients with suramin or metrifonate. | the application of a new technique is described permitting a better recognition of activities of drugs on macrofilariae of onchocerca volvulus. in two villages of a hyperendemic focus in liberia onchocercomata were excised from untreated persons and from patients treated with conventional doses of suramin or metrifonate. the adult worms were enzymatically isolated with collagenase and microscopically examined for degenerative alterations including calcifications and for the presence of eggs and ... | 1980 | 7414675 |
| entomologic considerations in the study of onchocerciasis transmission. | the entomological resources utilized for a better understanding of onchocerca volvulus transmission are discussed in this paper. vector density, anthropohilia, gonotrophic cycyle, parous condition longevity and probability of survival in days after the infectious meal are assessed here in order to integrate an overall picture. the concept of vectorial capacity is developed stressing the quantitative aspects. parasitism of the black-flies by filariae that are doubtfully identified as o. volvulus ... | 1980 | 7425779 |
| onchocerciasis of the flexor compartment of the forearm: a case report. | a 36-year-old white male schoolteacher presented with a painless, semifluctuant mass on the volar aspect of his forearm and symptoms of ring finger tenosynovitis and median nerve compression. at operation there was a widespread infestation of the flexor tendon compartment, the carpal tunnel, and the tendon sheaths of the ringer finger with onchocerca volvulus, a filarial nematode, not previously reported in the these tissues. | 1980 | 7430589 |
| mepacrine--ineffective in onchocerciasis. | mepacrine in doses of 200 mg b.d. for 5-7 days given to six patients from the rain-forest zone of nigeria showed neither micro- nor macrofilaricidal activity against onchocerca volvulus. | 1980 | 7445069 |
| [the different types of human onchocerciasis in west africa (author's transl)]. | this study reports the clinical, ophtalmological and parasitological examination for onchocerciasis in 4 882 people, living in 23 villages located in 8 different areas of west africa. the disease is hyperendemic in the whole sample and no major differences occur when comparing the indices of onchocerca volvulus infection. however, all the complications (eye, skin and lymph node lesions) are less common in the four forest clusters than in to the four savanna clusters. the disease seems to be rela ... | 1980 | 7458161 |
| life span and distribution of onchocerca volvulus microfilariae in mice. | microfilariae of onchocerca volvulus obtained from onchocercomas were inoculated subcutaneously into the inguinal region of mice. microfilariae disseminated rapidly, invading the tail and lungs within 1 hr and the ears within 3 hr postinoculation. during the early period of infection microfilariae appeared in the eyes, ears, viscera, pelt, carcass, and tail; later, the microfilariae tended to accumulate in the tail. liver microfilariae were recovered up to 12 wk postinoculation. intraperitoneal ... | 1980 | 7463248 |
| what can a worm teach us about autoimmunity? | | 1995 | 7475765 |
| social and psychological aspects of onchocercal skin disease in nebbi district, uganda. | onchocerciasis affects 7% of uganda's population and 1.5 million more people are at risk of infection with onchocerca volvulus, the nematode that causes the disease. this paper reports the results of part of a multi-centre study whose objective was to determine the prevalence of onchocercal skin disease and its associated psychosocial importance in uganda. the study employed a standardised clinical dermatological survey method along with the use of structured questionnaires, focus group discussi ... | 1995 | 7498028 |
| comparison of the patterns of codon usage and bias between brugia, echinococcus, onchocerca and schistosoma species. | patterns of codon usage and bias were compared among taxa of the genera brugia, echinococcus, onchocerca and schistosoma by metric multidimensional scaling and three commonly used indices of bias: nc, gc3s and b. the overall codon usage for each taxon was compared, as was the codon usage for each individual gene within the taxa. differences in the patterns of codon usage observed between taxa were dependent on the overall base composition of the genes analysed. the codon usage of echinococcus wa ... | 1995 | 7501637 |
| cell-adhesion molecules expressed by activated eosinophils in onchocerca volvulus infection. | cell-adhesion receptors mediate the interaction between host effector cells and cellular or multicellular targets, including opsonized parasites. our recent finding of a deposition of plasma proteins, including fibronectin, on the surface of infective larvae of the helminthic parasite onchocerca volvulus led us to investigate the possible expression of cell-adhesion molecules (cam), particularly fibronectin receptors, on eosinophilic granulocytes from persons infected with o. volvulus. immunoflu ... | 1995 | 7501639 |
| ultrastructure study of the excretory system and the genital primordium of the infective stage of onchocerca volvulus (nematoda:filarioidea). | the electron microscopic investigation of the anterior part of the infective third-stage juvenile of onchocerca volvulus provides first insights into the structure of the excretory system of this developmental stage of the parasite. the most anterior part of this system consists of a cell process of the syncytial excretory cells. at this height the excretory cells enclose the cuticle-lined excretory channel. the channel is in the process of elongation in the anterior-posterior direction, indicat ... | 1995 | 7501640 |
| major retinal cell components recognized by onchocerciasis sera are associated with the cell surface and nucleoli. | cellular localization of the components recognized by onchocerciasis autoantibodies has not been investigated in any detail in cultured retinal cells. this study sought to examine, in cultured retinal cells, the subcellular localization of major components that cross-react with onchocerciasis sera. | 1994 | 7510272 |
| recent evolutionary history of american onchocerca volvulus, based on analysis of a tandemly repeated dna sequence family. | polymerase chain reaction (pcr) products were characterized for a repeated sequence family (designated "o-150") of the human filarial parasite onchocerca volvulus. in phylogenetic inferences, the o-150 sequences clustered into closely related groups, suggesting that concerted evolution maintains sequence homology in this family. using a novel mathematical model based on a nested application of an analysis of variance, we demonstrated that african rainforest and savannah strain parasite populatio ... | 1994 | 7516998 |
| pathogenesis of onchocercal dermatitis: possible role of parasite proteases and autoantibodies to extracellular matrix proteins. | we examined the immunogenicity of various connective tissue proteins in patients with chronic onchocercal dermatitis and the effect of filarial proteases on this host-parasite interaction. sera from patients with onchocerciasis reacted strongly with cuticular collagens from filarial parasites and with mammalian laminin. some sera also contained antibodies to elastin and collagen type iv, but none reacted with collagen types i-iii or fibronectin. this pattern of reactivity was characteristic for ... | 1994 | 7520005 |
| epitopes of the onchocerca volvulus ral1 antigen, a member of the calreticulin family of proteins, recognized by sera from patients with onchocerciasis. | ral1 is an antigen (ag) encoded by the filarial nematode onchocerca volvulus, the parasite causing onchocerciasis (river blindness). ral1 shares 64.4% identity with the autoantigen calreticulin. the striking similarity of the parasite ag and the human autoantigen has led to the hypothesis that ral1 may induce a cross-reactive immune response to calreticulin, which in turn may be involved in the pathogenesis of onchocerciasis. to test this hypothesis, we explored the immune response to ral1 recom ... | 1994 | 7520419 |
| molecular characterization of a parasite antigen in sera from onchocerciasis patients that is immunologically cross-reactive with human keratin. | onchocerca volvulus is a nematode that causes severe dermatitis and blindness in humans. prior studies have shown that immune complexes in sera from onchocerciasis patients contain parasite antigens with m(r) of 23,000 and 65,000-70,000. monoclonal antibody ov-1 binds to these antigens and to corresponding antigens in adult worm extracts and in vitro culture supernatants. ov-1 was used to immunoscreen an o. volvulus adult worm cdna library. clone ov1cf contains a 1632-bp open-reading frame that ... | 1995 | 7539474 |
| identification of recombinant filarial proteins capable of inducing polyclonal and antigen-specific ige and igg4 antibodies. | filarial infection is characterized by an immune response associated with the production of ag-specific igg4 and ige and il-4 and il-5. to identify filarial ags capable of inducing such responses and to analyze the role ags themselves play in sustaining it, 24 recombinant filarial parasite proteins were screened for their ability to be recognized by sera from 67 individuals with tissue-invasive filarial infections. among the recombinant proteins that were recognized by igg4 or ige abs in 25% of ... | 1995 | 7543519 |
| salivary apyrase in new world blackflies (diptera: simuliidae) and its relationship to onchocerciasis vector status. | salivary gland apyrase is believed to be critical to blood-feeding in arthropod vectors. this enzyme was measured in six new world blackflies representing three taxonomic pairs of non-vectors and vectors of onchocerca volvulus. in simulium (psilopelmia) ochraceum, a highly anthropophilic vector in mexico and guatemala, apyrase exhibited maximum activity between ph 8.0 and 9.0, mean 39.8 +/- 4.7 milliunits/pair of gland equivalents (mu), and was enhanced when atp was used as a substrate. in the z ... | 1995 | 7548952 |
| molecular and immunological characterization of hr44, a human ocular component immunologically cross-reactive with antigen ov39 of onchocerca volvulus. | structural similarities between host self-antigens and infectious organisms may be involved in the expression of autoimmune reactivity and development of autoimmune disease. the unique eye pathology associated with onchocerca volvulus infection, particularly the development of posterior segment lesions, may be promoted by such autoreactive responses. ov39 is a parasite-derived antigen that has been shown previously to be antigenically cross-reactive with a 44,000-m(r) host ocular component. a cl ... | 1995 | 7561685 |
| interleukin 4 and t helper type 2 cells are required for development of experimental onchocercal keratitis (river blindness). | inflammation of the corneal stroma (stromal keratitis) is a serious complication of infection with the nematode parasite onchocerca volvulus. because stromal keratitis is believed to be immunologically mediated in humans, we used a murine model to examine the role of t cells and t helper cell cytokines in the immunopathogenesis of these eye lesions. balb/c mice immunized subcutaneously and injected intrastromally with soluble o. volvulus antigens (ovag) developed pronounced corneal opacification ... | 1995 | 7561696 |
| the effect of ivermectin treatment on the antibody response to antigens of onchocerca volvulus. | the effect of the microfilaricidal drug ivermectin on the antibody response to a detergent extract of adult onchocerca volvulus (ovag) and a number of specific recombinant peptides was examined. three of the peptides were combined in a serodiagnostic 'cocktail' and the effect of ivermectin on the diagnostic performance of this assay was assessed. immunoglobulin (ig) g1 serum levels in response to ovag significantly decreased following ivermectin treatment. the antibody response to only one recom ... | 1994 | 7570844 |
| evaluation of alternate methods of rapid assessment of endemicity of onchocerca volvulus in communities in southern cameroon. | potential diagnostic indicators of onchocerciasis (subcutaneous nodules, depigmentation or leopard skin, microfilaruria, diethylcarbamazine patch test positivity, excoriations, and pruritus) were evaluated in a rain forest region of southern cameroon for usefulness in rapid assessment of onchocerciasis endemicity in communities. thirty-two study villages were selected, representing high, intermediate, and low prevalence levels, and 846 adult male residents of these communities 20 or more years o ... | 1995 | 7573705 |
| dna sequence analysis using hierarchical art-based classification networks. | adaptive resonance theory (art) describes a class of artificial neural network architectures that act as classification tools which self-organize, work in realtime, and require no retraining to classify novel sequences. we have adapted art networks to provide support to scientists attempting to categorize tandem repeat dna fragments from onchocerca volvulus. in this approach, sequences of dna fragments are presented to multiple art-based networks which are linked together into two (or more) tier ... | 1994 | 7584398 |
| an immunodominant antigen of brugia malayi is an asparaginyl-trna synthetase. | lymphatic filariasis is caused by infection with the filarial nematodes brugia malayi, brugia timori, wuchereria bancrofti and onchocerca volvulus which collectively infect about 200 million persons throughout the world. protein sequence homology analysis of a major nematode antigen suggested that it was a class ii aminoacyl-trna synthetase. the overproduction, purification and verification that the major b. malayi antigen is an asparaginyl-trna synthetase is described. | 1995 | 7589498 |
| onchocerca volvulus larval antigen, ovb20, induces partial protection in a rodent model of onchocerciasis. | ovb20 is an antigen of onchocerca volvulus preferentially recognized by sera from cattle vaccinated with irradiated infective larvae of onchocerca lienalis. antibodies raised against the recombinant protein were used to characterize the expression of the native protein in different developmental stages of o. volvulus and the rodent filaria acanthocheilonema viteae. in o. volvulus, antibodies reacted to a polypeptide of 42 kda in microfilariae and with proteins of 52 and 65 kda in third-stage lar ... | 1995 | 7591079 |
| determining the prevalence of onchocerca volvulus infection in vector populations by polymerase chain reaction screening of pools of black flies. | an important variable in the epidemiology of arthropodborne diseases is the intensity of transmission, which is a function of host-vector contact and the prevalence of infection in the vector population. this latter value is often difficult to estimate. it is possible to envision the application of polymerase chain reaction (pcr) assays to this problem. to accomplish this, the assay must detect a single infected vector in a pool containing a large number of uninfected individuals. it must also b ... | 1995 | 7594692 |
| glycolipid antigens of adult o. volvulus reactive with patients sera from onchocerciasis endemic areas in cameroon. | lipid extraction of adult o. volvulus worms using a chloroform/methanol/water mixture yielded 10 lipid fractions of which 8 were demonstrated by the orcinol reagent to be glycolipids. in tlc, two of these lipid fractions had mobilities similar to cholesterol and cholesterol ester (rf.: 0.95, 0.86) whereas two others migrated as sphingomyelin and lecithin (rf.: 0.40, 0.35) respectively. other components migrated at intermediate positions. the glycolipids were immunologically active and reacted wi ... | 1994 | 7604752 |
| effect of repeated treatments with ivermectin on the incidence of onchocerciasis in northern cameroon. | mass treatments with ivermectin have been undertaken each year since 1987 in an area hyperendemic for onchocerciasis in northern cameroon. the impact of these successive treatments on the incidence of infection in humans was evaluated by comparing the prevalence of skin microfilariae (pmf) and the mean microfilarial skin densities (mfd) observed in 1987 and 1992 in 5-7-year-old children who had never taken the drug but who were members of the treated communities. in 1992, the pmf and the mfd in ... | 1995 | 7625535 |
| onchocerca volvulus: a comparative study of in vitro neutrophil killing of microfilariae and humoral responses in infected and endemic normals. | in vitro neutrophil-mediated microfilarial killing, humoral responses to crude adult worm antigens (ovag) and to four recombinant onchocerca antigens (gst-ov7, gst-ov103, gst-ov3.6, and mbp-ov16), as well as western blot analysis to stage-specific onchocerca proteins were studied in individuals from bassa county, liberia, infected with onchocerciasis and in endemic normals, defined as individuals without microfilaridermia. both groups exhibited high levels of specific serum-dependent killing of ... | 1995 | 7628571 |
| an abundant, trans-spliced mrna from toxocara canis infective larvae encodes a 26-kda protein with homology to phosphatidylethanolamine-binding proteins. | a full-length mrna encoding a secreted 26-kda antigen of infective larvae of the ascarid nematode parasite toxocara canis has been identified. this was characterized as a 1,082-base pair clone highly abundant (0.8-1.9%) in cdna prepared from infective stage larvae but absent from cdna from adult male worms. sequence analysis revealed an open reading frame corresponding to a hydrophilic 263-amino acid residue polypeptide with a 20-residue n-terminal signal peptide, indicating that it is secreted. ... | 1995 | 7629180 |
| cloning of a schistosoma japonicum gene encoding an antigen with homology to calreticulin. | a recombinant lambda gt11 clone, ivgs3, encoding part of a 55-kda antigen was isolated from an adult schistosoma japonicum cdna library. the protein expressed by this clone was recognised strongly by serum from rats that had been vaccinated with irradiated cercariae (vrs) rendering them highly immune to a challenge infection. antibodies in vrs which were specific for ivgs3 did not recognise adult worm antigens of s. mansoni, suggesting that the recombinant antigen contains species-specific epito ... | 1995 | 7630385 |
| prevalence, geographical distribution and clinical manifestations of onchocerciasis on the island of bioko (equatorial guinea). | a survey for the prevalence, geographical distribution and clinical manifestations of onchocerciasis was conducted on the island of bioko (formerly fernando póo), equatorial guinea, between 1987-89. the whole population (1799 inhabitants) of thirteen villages distributed around the island was surveyed. identification data, physical examination and snellen "e" test for visual acuity were performed. skin snips were taken from both iliac crests and right scapula and calf. differential diagnosis bet ... | 1995 | 7631122 |