Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042961 (volvulus)
 4,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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 stable antigen of M(r) 46,000. This antigen was not present in the circulating immune complexes (CIC) prepared from patients with Wuchereria bancrofti infection, but a cross-reactive molecule of the same size was weakly recognized in the CIC of Loa loa and Mansonella perstans infected patients. No association between the level of parasite specific CIC and clinical disease was observed in the O. volvulus patients.
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PMID:Identification and characterization of a parasite antigen in the circulating immune complexes of Onchocerca volvulus infected patients. 128 95

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 3-7 stained the basal layer. A sandwich ELISA was then developed. The trapping polyclonal antibody was raised in rabbits utilising the same antigens as for preparation of the MOVs. Once captured on microtiter plates, target antigens were identified by the sequential binding of a MOV, followed by a goat anti-mouse globulin/peroxidase or alkaline phosphatase conjugate that catalysed a colorimetric reaction in the presence of appropriate substrates. In this system, MOV 1 emerged as the most specific and potent reagent capable of recognizing antigens of Onchocerca sp. with a minimal detection limit of 78 ng per test. MOV 1, failed to react with extracts of Loa Loa, Ascaris lumbricoides and Ascaris suum in the test. The developed assay relied on the use of MOV 1, required only 1 ml of urine or 0.05 ml serum. About 97.8% of the 47 urines and 50% of the 20 sera from patients studied gave positive results. Only 1 (3%) of 32 control urines and up to 80% of the 10 control sera studied tested positive, suggesting urine as a better specimen source.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A monoclonal antibody-based immunodiagnostic assay for onchocerciasis. 138 17

Eosinophil infiltration and degranulation around the tissue-invasive stages of several species of helminths have been observed. Release of eosinophil granule contents upon the worms is supported by localization of two of the major granule proteins, major basic protein (MBP) and eosinophil peroxidase (EPO), on and around species of trematodes, nematodes, and cestodes. In the case of filarial worms, MBP is deposited on degenerating microfilariae (mf) of Onchocerca volvulus. Here, we performed in vitro assays of the toxicity of four purified eosinophil granule proteins, namely, MBP, EPO, eosinophil cationic protein (ECP), and eosinophil-derived neurotoxin (EDN), for the mf of Brugia pahangi and Brugia malayi. MBP, ECP, and EDN killed these worms in a dose-related manner although relatively high concentrations of EDN were necessary. EPO, in the presence of a H2O2-generating system and a halide, was the most potent toxin on a molar basis; here, the most potent halide was I- followed by Br- and Cl-. Surprisingly, EPO in the absence of H2O2 killed mf at concentrations comparable to those required for MBP and ECP. The toxicity of EPO + H2O2 + halide was inhibited by heparin, catalase, or 1% BSA, whereas the toxicity of EPO alone was inhibited only by heparin. Heparin also inhibited killing by both MBP and ECP. Despite the homology of ECP with certain RNases, placental RNasin, an RNase inhibitor, was unable to inhibit ECP-mediated toxicity. These results indicate that all of the eosinophil granule proteins are toxic to mf and they support the hypothesis that eosinophil degranulation causes death of mf in vivo.
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PMID:In vitro killing of microfilariae of Brugia pahangi and Brugia malayi by eosinophil granule proteins. 232 97

Three foci of onchocerciasis transmission (two forest and one savanna, respectively) in the Republic of Ivory Coast were chosen for a comparative analysis of Onchocerca volvulus antigens and of patients' antibody responses. Clear differences between frequency and intensity of ocular pathology existed between the forest foci and the savanna focus. We found heterogeneity of SDS-PAGE-separated components of female worms with respect to the mobility of three protein bands of the 100 KD region and to the ability of an 80 KD band to bind horseradish peroxidase. These variations were clearly not associated with the degree of ocular pathology. No differences in the composition of worm antigens were detected by immunoblotting. A variable with a possible relation to ocular pathology was the antibody response of patients: individuals from the savanna focus, where a high degree of ocular pathology is observed, tended to have a stronger and more differentiated IgG antibody response against O. volvulus antigens than patients from the forest foci. However, no antigens specifically recognized by patients from either forest or savanna were detected.
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PMID:Antibody responses in forest and savanna onchocerciasis in Ivory Coast. 282 35

Chronic hyperreactive onchodermatitis (sowda) is a severe form of onchocerciasis observed in a subset of individuals infected with the filarial nematode Onchocerca volvulus. SDS-PAGE and immunoblot analyses of O. volvulus adult worm extracts were used to characterize the antigens of the marked antibody response of sowda patients. One 2.5-kD antigen was recognized by sera from all 35(100%) sowda patients that were studied. In comparison, only 7 of 44 (16%) patients with generalized onchocerciasis and 11 of 21 (52%) of exposed individuals with no microfilariae in skin snips and no signs of disease showed reactivity to this antigen. Microfilaricidal treatment of sowda patients with improvement of the clinical status was associated with a decrease or disappearance of antibodies to the 2.5-kD antigen. Amino acid sequencing of the antigen indicated identity to human defensins 1-3 of neutrophils. Defensin was demonstrated by immunohistochemical staining in onchocercal nodules on the surface of adult filariae and in the surrounding tissue. A similar staining pattern was observed for other proteins present in neutrophils such as myeloperoxidase, elastase, and the L-1 protein complex (MRP 8/MRP 14), indicating that neutrophils, macrophages, and their proteins predominate in the environment adjacent to the worms. These results demonstrate an association between the presence of autoantibodies to defensins and an infectious disease of known etiology. The association with a particular form of onchocerciasis, sowda, suggests a link between formation of autoantibodies to defensin and enhanced immune reactivity towards the parasite.
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PMID:Human autoantibody to defensin: disease association with hyperreactive onchocerciasis (sowda). 779 Aug 22

Onchocercomata with a single live or dead worm were analyzed to elucidate the infiltration of eosinophils. Females were classified according to the presence or absence of microfilariae in their uteri and in the nodular tissues. Immunohistochemical staining was performed using antibodies against eosinophil cationic protein, peroxidase, and major basic protein. Very few eosinophils were detected in nodules containing females without microfilariae or male or dead worms only, whereas eosinophils were abundant in all nodules with females producing microfilariae. The occurrence of eosinophils was not related to the age of the worm. Occasionally, degenerated or dead microfilariae attacked by activated eosinophils were found. By examination of onchocercomata with or without microfilariae from the same patient, it was excluded that the occurrence of eosinophils was dependent mainly on the host's immune status. In conclusion, live adult Onchocerca volvulus do not elicit an invasion of eosinophils as long as they do not produce microfilariae. The absence of eosinophilia does not exclude onchocerciasis.
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PMID:Dependence of eosinophil granulocyte infiltration into nodules on the presence of microfilariae producing Onchocerca volvulus. 882 5

The participation of neutrophil granulocytes in the cellular reaction to skin microfilariae of Onchocerca volvulus was studied by immunohistochemistry. Skin biopsies were obtained from adult Liberian and Ugandan patients with generalized onchocerciasis after exposure to topically applied diethylcarbamazine (DEC) and from untreated patients. After DEC many damaged microfilariae were observed either in dermal infiltrates or in epidermal microabscesses consisting both of neutrophils and eosinophils. Infiltrates and microabscesses contained some intact granulocytes and many neutrophils releasing myeloperoxidase, elastase, lactoferrin, defensin, lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin. Eosinophils discharged peroxidase and cationic proteins. Released granule proteins and remnants of disrupted granulocytes were found on the surface and in close proximity of damaged microfilariae in dermal infiltrates and epidermal microabscesses. In larger microabscesses neutrophils were predominant. These observations show that neutrophils and not only eosinophils recruit, accumulate, localize around and release their helminthotoxic granule proteins such as myeloperoxidase onto or closely around skin microfilariae of O. volvulus after topical DEC administration. The association between these processes and the damage of the microfilariae indicated that neutrophils together with eosinophils attack and damage microfilariae of O. volvulus after DEC treatment in the skin.
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PMID:Neutrophil granule proteins: evidence for the participation in the host reaction to skin microfilariae of Onchocerca volvulus after diethylcarbamazine administration. 887 78

Sensitive, specific and low-cost diagnostic tests for onchocerciasis are indispensable for monitoring the efficacy of control programs, as well as for preventing blindness (when the tests are combined with efficacious chemotherapy. Three new tests to detect Onchocerca-specific antigens in tears, dermal fluid and urine employ antibodies to O. volvulus-specific recombinant proteins, Oncho-C27 and OvD3B, encoded by genes within the immunodominant Onchocerca OV 33-3 gene family, and expressed in yeast and in E. coli, respectively. In these assays, Onchocerca-specific antigens in test samples are bound onto a solid surface and revealed using appropriate enzyme-labelled antibodies. Proteins in the samples are first transferred to Hybond-N + membrane disks or nitrocellulose paper using either a transblot or a dotblot machine, and then reacted with specific O. volvulus antibodies. Bound antibodies are revealed with species-specific peroxidase-labelled antibodies and peroxidase substrate. Positive tests give a brown colour. In one of the two assays developed to detect Onchocerca antigens in tears, the sensitivity was enhanced by first adsorbing the specific antibodies onto the membrane surface in order to immobilize and concentrate the Onchocerca-specific antigen molecules on the membrane. The specificity of the recombinant proteins for Onchocerca volvulus had been verified by ELISA, classical Western blot and modified DSIA. The tests are a dipstick immunobinding assay for ocular microfilariae (DSIA), a transblot immunobinding assay for the detection of skin microfilariae (TADA) and a dot-blot immunobinding assay for detecting urinary microfilariae and their antigens (DIA). Their specificity and sensitivity were evaluated in the field on 110 subjects with proven ocular microfilariae, 130 subjects with clinical and parasitological evidence of onchocerciasis, 25 subjects infected with other helminths and 120 normal controls. The minimal detection limits of Oncho-C27 protein by DSIA, TADA and DIA were 500 ng/ml, 154 ng/ml and 508 ng/ml, respectively By contrast, their sensitivities were: 100% for DSIA and 82.5% for TADA employed on samples of tears; 97% for TADA skin test and 96% for DIA used on urine samples.
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PMID:Novel, sensitive and low-cost diagnostic tests for 'river blindness'--detection of specific antigens in tears, urine and dermal fluid. 962 38

Eosinophils, eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN/EPX), myeloperoxidase (MPO) and IgE were measured in blood, serum and/or urine in Schistosoma haematobium- and Onchocerca volvulus-infected Guineans and O. volvulus- and S. haematobium-negative Guineans coinfected or infected with intestinal nematodes. The number of eosinophils and levels of eosinophil granule proteins but not of MPO were found to be strongly elevated in all Africans as compared to European controls. The highest serum ECP and serum and urinary EDN/EPX levels were observed in the hyperreactive form of onchocerciasis (sowda). Onchocerciasis patients and O. volvulus-negative Africans coinfected or infected with intestinal nematodes (hookworm and/or Ascaris lumbricoides) revealed higher serum granule protein concentrations and/or absolute eosinophil counts and urinary ECP than those without nematode infections. Statistical differences between both sections were found for the absolute eosinophil counts and for serum EDN/EPX and IgE in generalized onchocerciasis, and for urinary ECP in sowda, indicating stimulation of the eosinophil potential of O. volvulus-positive patients by coexistent hookworm infection. This worm species, in contrast to A. lumbricoides, causes especially high eosinophil counts and EDN/EPX and IgE levels. From these results it is concluded that in nematode diseases, ECP and EDN/EPX levels reflect the degree of antigenic stimulation, eosinophil activation and eosinophil turnover rates. Serum ECP and serum and urinary EDN/EPX may, therefore, serve as parameters to monitor helminth infection. Urinary ECP may be a marker of eosinophiluria secondary to urogenital manifestation of S. haematobium. It is elevated in hyperreactive onchocerciasis activated by intestinal nematodes.
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PMID:Eosinophils, eosinophil cationic protein and eosinophil-derived neurotoxin in serum and urine of patients with onchocerciasis coinfected with intestinal nematodes and in urinary schistosomiasis. 1020 16

We report the cloning, expression and functional characterisation of a peroxidase belonging to the peroxiredoxin family from the potato cyst nematode Globodera rostochiensis, the first molecule of this type from any nematode parasitic on plants. The G. rostochiensis peroxiredoxin catalyses the breakdown of hydrogen peroxide, but not cumene or t-butyl hydroperoxide, in a trypanosomatid reducing system comprising trypanothione reductase, trypanothione and tryparedoxin. In common with its homologues from Onchocerca volvulus and Brugia malayi, the G. rostochiensis enzyme is present on the surface of invasive and post-infective juveniles despite the apparent lack of a cleavable N-terminal signal peptide. The possibility that the G. rostochiensis peroxiredoxin plays a role in protection of the parasite from plant defence responses is discussed.
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PMID:Cloning, expression and functional characterisation of a peroxiredoxin from the potato cyst nematode Globodera rostochiensis. 1108 15


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