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)

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 onchocerciasis patients. 153 sera from Sierra Leonean patients were tested for their individual antibody levels against antigen epitopes recognised by Cam1 and Cam28. Patients within the age of 5-8 years had the highest levels of antibodies against the Cam28-epitope, whereas patients above 60 years had almost none. Amicrofilaremic patients had higher anti-Cam28 antibody levels than microfilaremic patients and there was a significant difference between groups with no chronic skin disease and those with mild or severe signs. A high percentage of patients (80.4%) recognised the Cam1-epitope, highest antibody levels being found in patients within the age group of 15 to 45 years and in microfilaremic patients. However, levels of antibodies inhibiting monoclonal antibody Cam1 could not be correlated with presence or absence of skin disease.
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PMID:Analysis of antibody responses directed against two Onchocerca volvulus antigens defined by monoclonal antibodies. 159 8

It is not clear what role immediate hypersensitivity immune responses have in the pathogenesis of human onchocerciasis, but it is certain that these responses are prominent both in the course of natural infection and during the Mazzotti reactions that follow treatment with diethylcarbamazine. In humans, the levels of total serum IgE associated with onchocerciasis are as high or higher than those associated with almost any helminth infection, although specific IgE antibodies to Onchocerca volvulus appear to be a small and still poorly characterized fraction of the total serum IgE. Evidence about the relationship of these prominent IgE responses in patients with onchocerciasis to the onchocercal skin disease that manifests as pruritus and papular eruptions is conflicting, but in a guinea pig model of ocular pathology induced by onchocerca microfilariae evidence for the pathogenetic importance of IgE and immediate hypersensitivity is much less equivocal. The suggestive findings from this model make it imperative to carry out similar studies of Onchocerca-affected human eyes to determine whether immediate hypersensitivity responses play a similar critical role in the pathogenesis of the ocular lesions in humans.
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PMID:Immediate hypersensitivity responses in the immunopathogenesis of human onchocerciasis. 407 Sep 17

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.
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PMID:Onchocerciasis in Sudan: the Abu Hamed focus. 408 57

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 discussions and key informant interviews. Out of a total of 993 persons examined to determine the prevalence of onchocercal skin lesions 253 persons were interviewed to determine the psychosocial importance of the disease. The results indicate that onchocercal skin disease is associated with a variety of psychosocial, physical and economic effects. The disease also leads to stigmatisation of affected persons and their families. It is suggested that dermatological effects of onchocerciasis should be recognised as an important cause of morbidity in Uganda.
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PMID:Social and psychological aspects of onchocercal skin disease in Nebbi district, Uganda. 749 28

Antigen (Ag)-specific isotype responses to Onchocerca volvulus Ag (OvAg) were assessed by enzyme-linked immunosorbent assay and immunoblot in 123 residents of a mesoendemic area in northern Nigeria and 16 Nigerians from a nonendemic area. Individuals from an endemic area were divided into six groups on the basis of cutaneous onchocercal pathology: acute papular onchodermatitis (APOD), chronic papular onchodermatitis (CPOD), lichenified onchodermatitis (LOD), atrophy (ATR), depigmentation (DPM) and normal skin, high microfilarial load (NSHMF). Immunoglobulin (Ig)G1-4 levels were all significantly associated with residence in an endemic area after controlling for age and sex (all P values = 0.0001). Both IgG1 and IgG3 were significantly associated with onchocercal clinical category after controlling for age, sex, and microfilarial load (P = 0.0031 and 0.0035, respectively). The IgG1 and IgG3 responses were both highest in LOD and lowest in NSHMF and ATR, respectively. A significant inverse association was found between IgG1 levels and microfilarial load after controlling for age, sex, and clinical category (P = 0.0061). On immunoblotting, 20 (44.4%) of 45 individual onchocerciasis sera contained IgG4 antibodies against a band of 29-31 kD, which was not recognized by pooled sera from individuals with other filarial infections. There was heterogeneity of antigen recognition within each of the onchocercal clinical groups, which together with the small numbers examined by immunoblotting, limits interpretation. Nevertheless, some differences in patterns of antigen recognition were found between the onchocercal groups. The LOD group demonstrated prominent immunoreactivity in IgG1 and IgG3 while a general paucity of low molecular weight reactivity was seen with NSHMF in IgG1-3 subclasses, but there was no specific banding pattern that differentiated NSHMF from those with pathology. Comparison of microfilariae-positive (mf+) and mf- individuals with onchocercal skin disease revealed significantly higher levels of all IgG subclasses and higher overall scores on semiquantitative assessment of immunoblots for IgG1, IgG2, and IgG4 for mf+ individuals. Differing isotypic responses may play a role in the pathogenesis of the clinical spectrum of cutaneous onchocerciasis.
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PMID:Human onchocerciasis in Nigeria: isotypic responses and antigen recognition in individuals with defined cutaneous pathology. 868 79

The cellular and subcellular localization of cationic leukocyte antigen (CLA) in human peripheral blood and tissue granulocytes was investigated by immunoenzymatic labeling and by immunoelectron microscopy. Human peripheral blood granulocytes from healthy individuals and from subjects with eosinophilia of varying etiology, as well as intravascular and/or perivascular granulocytes in skin biopsies taken from patients with generalized onchocerciasis, a skin disease caused by microfilariae of Onchocerca volvulus, were studied. Controlled indirect immunoenzymatic staining for CLA in cytospin preparations of buffy coat cells and in histological sections of skin biopsies revealed that this protein was exclusively found in the cytoplasm of eosinophil granulocytes. Furthermore, immunogold labeling coupled with electron microscopy showed that CLA was specifically localized within the matrix of both the small non-crystalloid-containing pale granules and the large crystalloid-containing secondary granules of peripheral blood and tissue eosinophils. No specific gold labeling was observed in other organelles of eosinophils, in neutrophils, basophils, lymphocytes or monocytes.
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PMID:Cellular and subcellular localization of cationic leukocyte antigen (CLA) in human eosinophil granulocytes. 942 73

An estimated 17.7 million persons, most of them in Africa, are infected with the parasite Onchocerca volvulus. Onchocerciasis has caused blindness in 270,000 and left another 500,000 with severe visual impairment. Onchocerciasis also can cause disfiguring skin changes, musculoskeletal complaints, weight loss, changes in immune function, epilepsy, and growth arrest. The development of ivermectin and its donation by the manufacturer has reduced transmission in many parts of Africa and Latin America. Progress in developing a drug that can destroy adult worms has been slow, however. The immediate need is to extend ivermectin mass distribution to as many endemic areas as possible on a continuing basis, with steps toward community ownership of such programs. This article presents a comprehensive review of the literature on the epidemiology, parasitology, vector, symptoms, diagnosis, and treatment and control of onchocerciasis. Future research aims include fuller understanding of the parasite and its relationship with the host, the nature of the systemic effects of O. volvulus infection, the natural history of skin disease, and a better appreciation of the social and economic consequences of this parasitic disease.
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PMID:Onchocerciasis. 964 11

The parasitic helminth Onchocerca volvulus causes ocular onchocerciasis (river blindness) and onchocercal skin disease. To understand the immunologic basis for early stage skin disease, we developed a model in which C57B1/6 mice were immunized subcutaneously and injected intradermally (in the ear) with soluble O. volvulus antigens (OvAg). We found that ear thickness increased significantly after intradermal injection of OvAg and remained elevated for at least 7 days. Dermatitis was dependent on prior immunization, and was associated with an intense cellular infiltrate in the dermis. Neutrophils were the predominant inflammatory cells in the dermis 12 hr after intradermal injection, with only occasional eosinophils present. Conversely, increased ear thickness at later time points was associated with eosinophils, and neutrophils were only rarely detected. Both cell types were present at intermediate time points. These data indicate that recruitment of neutrophils and eosinophils to the skin is temporally regulated.
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PMID:Temporal recruitment of neutrophils and eosinophils to the skin in a murine model for onchocercal dermatitis. 1043 48

Infection by onchocerca volvulus, a parasitic worm, causes onchocerciasis (river blindness), a debilitating and often blinding disease endemic to tropical areas of Africa and Central and South America. The adult onchocerca volvulus invades the human host where it lives and reproduces for up to 14 years, creating millions of infant worms which cause itching, loss of skin color, rapid aging, and disfiguring skin disease in the host. Onchocerciasis often causes blindness in the human host by approximately age 35 years, and is the third leading cause of blindness in Africa. Onchocerca volvulus is transmitted among humans through the bite of blackflies which breed in fast-flowing rivers. The Onchocerciasis Control Program (OCP) was formally launched in 1974 by the UN's Food and Agriculture Organization (FAO), the UN Development Program (UNDP), the World Bank, and the World Health Organization (WHO) in Benin, Burkina Faso, Ghana, Cote d'Ivoire, Mali, Niger, and Togo. Vector control is the central strategy of the OCP, consisting of weekly helicopter spraying of larvacide to prevent the blackfly from reproducing and transmitting the disease. In addition, Merck & Co. is providing drug therapy against the infant worms in the human host free of charge to 16 million people in endemic areas. Onchocerciasis has now almost been eradicated in the 7 original target countries. Also through the OCP, by 1996, more than 34 million people were protected against the disease, about 2 million who were seriously infected have fully recovered, and an estimated 600,000 people have been prevented from going blind. 12 million infants born since the launch of the OCP face no risk of contracting the disease, and approximately 25 million hectares of arable fertile riverine land has been opened for resettlement. Labor productivity has also increased.
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PMID:River blindness. Protection for 54 cents a year. 1234 35

To assess the degree of skin disease in Simulium neavei s.s.-transmitted onchocerciasis, 72 patients infected with Onchocerca volvulus in the Kabarole district of Uganda were studied. They were clinically and parasitologically evaluated. Onchocercal skin lesions were determined using a modified Murdoch skin assessment, and skin scores were calculated. The chronic skin score (4.0) was associated with age, and the acute skin score (8.5) was significantly higher in males. The burden of onchocercal skin lesions was found to be high in most patients. The number of nodules (median number 1.9) and the microfilarial load (geometric mean of microfilaria 11.5) were not determinants for the burden of onchocercal skin disease in infected individuals. The study concludes that onchodermatitis is a serious medical condition in Kigoyera Parish and needs to be considered in all efforts to control onchocerciasis.
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PMID:Onchodermal skin disease in a hyperendemic onchocerciasis focus in western Uganda. 1247 47


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