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

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 of IgM, IgG, and IgA serum complexes (SC) containing a T. cruzi polypeptide epitope showed that SC could be detected in 69% of the 13 Chagasic acute phase sera studied with IgG, in 84% with IgM, and in 75% with IgA. Only 16% (IgG-SC), 8% (IgM-SC), and 10% (IgA-SC) of chronic sera from 50 patients were positive. No patients with toxoplasmosis or rheumatoid factor were positive. Of the 11 leishmaniasis sera studied, four had IgG-SC, two had IgA-SC, and five had IgM-SC. Of the eight Yanomamo Indians infected by Onchocerca volvulus, three were found to have IgG-SC, two had IgM-SC, and two had IgA-SC. Thirteen sera from healthy individuals living in an endemic area were also studied. One subject had IgG IgM and IgA-SC. The results presented in this study show for the first time, the specific detection of IgM, IgG, and IgA immune complexes using a MAb against T. cruzi. The presence of the epitope in association with IgM antibodies in sera from patients with the acute phase of the disease suggests that this antigen(s) carrying the epitope that reacts with the MAb could be a marker(s) of active infection. In addition, the specificity of the serum complex capture assay allowed the detection of Chagas' disease in two different endemic areas (Argentina and Venezuela).
 ...
PMID:Trypanosoma cruzi: a carbohydrate epitope defined by a monoclonal antibody as a possible marker of the acute phase of human Chagas' disease. 171 33

The population from five Guatemalan plantations in areas endemic for onchocerciasis was surveyed, and 1032 individuals were recruited to participate in our study. From physical examination, past clinical history (5 to 8 yr), laboratory evidence and sample availability, a group of 778 long term residents with confirmed disease status were selected for detailed examination. We were able to identify 268 long term residents of endemic areas who had never been infected, 44 of these are from hyper- and mesoendemic areas. The 44 uninfected individuals from the hyper- and mesoendemic areas, because of their considerable exposure to this disease, were classified as "putatively immune." Intact nodules containing adult worms of Onchocerca volvulus were homogenized in the presence of protease inhibitors and fractionated into particulate and aqueous isotonic soluble antigens. Systematic analysis of these Ag fractions showed considerable amounts of Ig, presumably associated with Ag in the form of immune complexes. Individual specific antibody reactions from all 778 patients to nodule Ag were examined. Reactions to O. volvulus antigens by antibodies from patients with confirmed parasitic infections were almost exclusively restricted to IgG1 and IgG4 isotypes. Antigenic activity appeared to be primarily associated with low molecular mass (14 to 29 kDa) components. Some competitive blocking of antibody activities of other isotypes by IgG1 was observed, most notable was that of IgG3 and IgA. IgG4 and IgM activities were not significantly blocked.
 ...
PMID:Guatemalan human onchocerciasis. I. Systematic analysis of patient populations, nodular antigens, and specific isotypic reactions. 203 67

The current status of onchocerciasis in Abu Hamed, Northern Province, Sudan, was studied. Of 208 persons attending out-patient clinics in villages in this region, 71 were microfilariae-positive on skin snips or had palpable nodules. Microfilariae and worms in nodules were identified as Onchocerca volvulus. No microfilariae were seen in peripheral blood. Most nodules and microfilariae were found in the pelvic region, but the intensity of infection was uniformly low (av. less than 3 mf/mg). Despite this, signs of onchocercal dermatitis were common and severe, especially over the buttocks. Papular eruptions and scarring often appeared to lead to black-grey hyperpigmentation, but no cases were seen of the unilateral, hyper-reactive 'sowda' described in Arabs in Yemen. No microfilariae were detected in the eyes of any of the patients who had positive outer canthus snips. Serum retinol concentrations were normal but mildly elevated concentrations of serum IgG, IgM and IgA were detected in many patients. Immunoglobulin E values in a sample of 20 microfilariae-positive patients were markedly higher than normal, with most in the 4,000 to 15,000 U/ml range. Eosinophil levels in differential counts of peripheral blood from the 208 villagers were markedly elevated. In skin snip surveys of over 400 villagers and school pupils, sample prevalence rates of 2 to 17.5% were recorded. Simulium biting was seasonal (November to May) and peaked in March. Over-all, the results indicate that O. volvulus infection persists in the Abu Hamed region as a serious cause of skin disease in the absence of other complicating filariases.
 ...
PMID:Onchocerciasis in Sudan: the Abu Hamed focus. 408 57

In Ecuador, previous epidemiological studies of onchocerciasis affecting a population consisting of Blacks of African origin and Amerindians of the Chachi tribe, have demonstrated different frequencies of clinical disease manifestations in each racial group. To explore the possibility of differential antibody responses to O. volvulus antigens in this population, a subset of sera from these two groups of Ecuadorians with onchocerciasis was analyzed for antibody to O. volvulus antigens using ELISA and Western blot techniques. Significantly higher levels of immunoglobulin against O. volvulus were demonstrated in Chachi Indians compared to native Blacks of African origin: total Ig (p = 0.049), IgG (P = 0.002) IgG4 (p = 0.019) and IgA (p = 0.035). Western blot analysis of sera from 41 persons demonstrated more intense and more frequent recognition of low molecular weight parasite antigens in the Chachi compared to a similar group of male and female Ecuadorian Blacks. These data suggest that the intensity of antibody responses to O. volvulus antigens may reflect the influence of racial factors in the pathogenesis of onchocerciasis in Ecuador.
 ...
PMID:Antibody responses to Onchocerca volvulus in Ecuadorian Indians and blacks. 825 87

The serum antibody response (total, and isotypes IgG1, IgG4, IgM, IgA and IgE) to Guinea worm infection was examined in humans from a highly endemic area of northern Ghana by ELISA and SDS-PAGE/Western blot techniques using an adult D. medinensis antigen. Sera were obtained early and late in the peak transmission period, from persons with patent and postpatent infections, as well as from persons from the same endemic area who claimed never to have had Guinea worm infection. To observe for potential cross-reactions in the tests, sera were also obtained from areas with no transmission of Guinea worm from patients with hookworm, O. volvulus and W. bancrofti infections, and from non-infected controls. Sera from persons living in the Guinea worm endemic area reacted extensively with Guinea worm antigen in both tests, and large numbers of bands were produced in the Western blots (up to 35 identified for some sera). For most antibody isotypes, the ELISA absorbance values obtained with sera from the same individuals varied between the two transmission seasons, with the highest titres present towards the end of the peak transmission period. The mean antibody titres for persons in the patent and postpatent infection categories were not significantly different when sera were obtained at the same season of the year. Persons from the endemic area, who claimed never to experience patent infections, also had antibodies to Guinea worm, although at significantly lower mean levels than for the patent and postpatent categories. The highest specificity in the ELISA and the most homogenous Western blots were obtained when detecting for antibodies of the IgG4 isotype.
 ...
PMID:The antibody response to Dracunculus medinensis in an endemic human population of northern Ghana. 850 17

Cattle experimentally infected with Onchocerca lienalis were examined by enzyme-linked immunosorbent assay and immunoblotting to determine the degree of stage- and species-specificity in the immune response to infection. Levels of serum antibodies to antigens derived from third-stage larvae increased little after the first three weeks of infection, and the range of antibody specificities remained limited following the appearance of microfilariae (mf) in the skin. In contrast, antibodies to antigens from adult worms of either sex exhibited a vigorous response, characterized by a series of peaks arising 15-30, 79, and > 266 days after infection that were coincident with the timings of larval molts and the onset of a patent infection. Antibody specificities to the adult worms included many directed to molecules that were shared with other life-cycle stages, but some were stage-specific and others were confined to one sex. A response cross-reactive with antigens from mf was initiated during the prepatent period, but antibody levels increased steeply after the infection became patent. This was followed by a major expansion of antibody specificities to products exclusively directed to mf, most notably in the range of 12-18 kilodaltons. Sera from O. lienalis-infected cattle cross-reacted extensively with antigens derived from O. volvulus adult worms and the profiles of antibody levels over time were indistinguishable from those obtained with O. lienalis extracts. The dominant response was of IgG1, although limited IgG2 and IgM reactivities were found, while no Onchocerca-specific IgA was detected. These results demonstrate that parasite development has a profound influence on the level and repertoire of antibodies produced during Onchocerca infections, and that extensive cross-reactivity exists between O. lienalis and O. volvulus, lending support to the role of cattle models in the study of human onchocerciasis.
 ...
PMID:Stage-specific and species cross-reactive antibody responses in experimental Onchocerca infections of cattle. 856 Dec 65

Immunization of mice with irradiated Onchocerca volvulus infective stage larvae (L3) has been demonstrated to confer protection against challenge infections with these larvae. Additionally, cytokine level measurements and cytokine depletion studies have shown that both IL-4 and IL-5 are important in generating a protective immune response against O. volvulus challenge infections, thus suggesting a dependency of protective immunity on IgG1, IgE and/or eosinophils. In the present study, we examined the humoral responses of immunized mice to O. volvulus L3 antigens. ELISA measurements of total serum antibody levels indicated that IgE was the only antibody isotype elevated in mice immunized with O. volvulus L3. IgM from immunized mice was the only isotype that recognized surface antigens on intact O. volvulus L3. IgG1, IgG3, IgE and IgA recognized internal parasite antigens on O. volvulus L3 frozen sections. Western blot analysis of L3 proteins showed that in serum from mice immunized with O. volvulus L3 IgG1, IgG2a/2b, IgA, and IgE, as well as IgM, recognized unique L3 proteins. Antibodies in serum from L3 immunized mice were able to detect O. volvulus adult antigens in a pattern similar to the recognition found in O. volvulus L3. Some L3 antigens were shared by adults, while other antigens were L3 specific. The ELISA, immunohistochemistry and Western blot findings thus demonstrate a complex pattern of antigen recognition of parasite antigens by antibodies found in mice immune to the L3 of O. volvulus.
 ...
PMID:Structural and molecular specificity of antibody responses in mice immune to third stage larvae of Onchocerca volvulus. 922 62

Human isotype specific antibody responses to a recombinant pi-class glutathione S-transferase (Ov24) from Onchocerca volvulus were assessed by ELISA, using a large and well-characterized bank sera (n = 238) from an hyper-endemic area of moderate intensity from Sierra Leone. IgG1, IgG4 and IgA responses, but neither IgG2 nor IgE response, to Ov24 were detected in infected subjects. The relationships between Ov24 antibody levels and skin microfilarial density, number of nodules, age, sex, eosinophil counts and clinical sign of reactive and chronic pathology were analysed using Pearson's correlation coefficient. Significant correlations between both IgA and IgG3 antibody levels and age were found (P < 0.01). Although no firm conclusions could be drawn from this study sample regarding the relationships between antibody levels and parasite load or clinical status, a negative correlation (P = 0.06) between Ov24 IgG3 antibody levels and microfilarodermia was found.
 ...
PMID:Human isotype antibody responses to an Onchocerca volvulus glutathione S-transferase. 922 91

The Onchocerca volvulus secretory protein Ov20/OvS1 represents a dominant antigen expressed in the infective larvae, microfilariae and adult stages of the parasite. The humoral responses to this protein have not yet been analysed in the polar clinical and immunological forms of onchocerciasis. Analysis by ELISA of class and subclass antibodies to Ov20/OvS1 in persons with the generalized or the hyperreactive form of onchocerciasis revealed similar strong responses of IgG1, IgG4 and IgM antibody levels in both forms of onchocerciasis and significant differences were observed in the IgE and IgA antibody classes. Computation of the ratios of antibodies showed that persons with the generalized form exhibited significantly higher ratios of IgG4 to IgG1, IgG4 to IgE, and IgM to IgE than patients with the hyperreactive form. To investigate the isotype recognition of antigenic sites on Ov20/OvS1 protein, three recombinantly expressed fragments (F1-3) of Ov20/OvS1 were probed using sera which strongly reacted with intact recombinant Ov20/OvS1. Epitope(s) on F1 comprising amino acid residues 1-63 were significantly recognized by IgG1 and IgE, while IgM recognized epitopes on all three fragments. The strongest reaction of IgM occurred with epitope(s) formed by residues 108-171 (F3). In contrast, IgG4 type antibodies were not reactive with either of the three OvS1 fragments, but they reacted with intact Ov20/OvS1 protein. Generalized onchocerciasis, unable to eliminate microfilariae, and hyperreactive onchocerciasis, with a high potency to eliminate or to reduce parasite loads, can be distinguished by a distinct pattern of isotype responses to Ov20/OvS1.
 ...
PMID:Humoral responses to a secretory Onchocerca volvulus protein: differences in the pattern of antibody isotypes to recombinant Ov20/OvS1 in generalized and hyperreactive onchocerciasis. 1097 52