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)

Antibodies to phosphorylcholine and carbohydrate determinants responsible for much of the cross-reactivity among nematodes are subclass restricted in humans and absent in the IgG4 subclass. Total IgG and IgG4 antibody responses to Onchocerca volvulus were examined by enzyme immunoassay and by immunoblot. Significant background IgG reactivity was detected in both assays in US control sera and sera from patients with intestinal nematode infections, but background reactivity was negligible in the IgG4 assays. IgG4 antibodies were detected by enzyme immunoassay in 17 of 18 Nigerian onchocerciasis serum samples and in 2 of 9 endemic control serum samples. Cross-reactive IgG4 antibodies were present in serum pools from patients infected with other filariae. IgG4 antibodies recognized a restricted subset of O. volvulus antigens in immunoblots relative to IgG. These results confirm the previously reported enhanced specificity of IgG4 antibody assays for filariasis and extend the observation to include onchocerciasis. Whereas IgG4 subclass antibody serology is more specific than measurement of total IgG antibodies for onchocerciasis, cross-reactivity among filariae limits the utility of this approach.
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PMID:IgG4 subclass antibody serology for onchocerciasis. 217 25

We examined the ability of two filarial species, Onchocerca volvulus and Brugia malayi, to solubilize collagen molecules from native collagen fibrils. Collagenolytic activity was detected in extracts of adult worms, in living microfilariae of O. volvulus and in live infective larvae and adult female worms of B. malayi. Excretion-secretion factors produced in vitro by infective larvae of B. malayi also contained large amounts of collagenase. Studies with enzyme inhibitors suggest that the latter may be a metallo-protease. Antibodies to filarial collagenase were present in sera from patients with onchocerciasis and brugian filariasis and from mice immunized with B. malayi. These antibodies and a monoclonal antibody raised against O. volvulus antigens immunoprecipitate filarial collagenase but appear not to be directed against the active site of the enzyme.
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PMID:Studies on a filarial antigen with collagenase activity. 242 72

Antigens containing phosphocholine (PC) circulate in the blood during chronic filarial infection. Because of the wide occurrence of such PC epitopes, we examined their specificity by evaluating 10 common parasites of humans for the presence of PC epitopes, and sera from patients infected with these parasites for circulating antigens containing PC. Immunoblot analysis of extracts from various parasites using an anti-PC monoclonal antibody (CA101) demonstrated the presence of PC epitopes on the protozoa Leishmania major and Trypanosoma cruzi, and on the helminths Schistosoma mansoni and Strongyloides stercoralis, in addition to those previously described on Trichinella spiralis, Onchocerca volvulus and Brugia malayi. They were not detected on the protozoa Entamoeba histolytica, Giardia lamblia or Plasmodium falciparum. Sera from 163 individuals with single protozoan or helminth infections were assayed for PC-bearing circulating antigens in a two-site immunoassay; such antigens were found in almost all patients infected with Wuchereria bancrofti; in half of those infected with S. stercoralis; and in 7-15% of those with S. mansoni, T. cruzi or L. donovani; none was detected in those with Trichinella, hookworm, Echinococcus, malaria, Giardia or amoebic infections. Thus, while detection of circulating PC-antigen as an immunodiagnostic assay for filariasis could result in some 'false positives', it appears to be a potentially valuable immunodiagnostic tool that deserves wider field testing to determine its practical usefulness.
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PMID:Phosphocholine epitopes on helminth and protozoal parasites and their presence in the circulation of infected human patients. 248 59

A study of relations between pruritus after doses of chloroquine and on the one hand the infection by Mansonella perstans (filariasis frequent in some areas but pathogenic) and on the other hand the infection by Onchocerca volvulus (filariasis frequent in some other areas but not very pathogenic) was carried out in two villages in Ivory Coast. It is not possible to show an obvious relation between the presence of pruritus and the two filariasis.
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PMID:[Pruritus after taking chloroquine and filariasis]. 254 69

1934 Bantus and 379 Pygmies were investigated for Loa loa and Mansonella perstans filariasis in 7 villages in the Chaillu forest of the Congo. Bantus were more frequently infected with L. loa than Pygmies (18.9% of microfilariae carriers compared with 10.6%). In individuals over 30 years of age, males were more frequently infected than females. Microfilarial densities increased until the age of 20 years and then remained stable. Parasite load was not significantly different in the two ethnic groups. For mansonelliasis, the microfilarial rate was higher in the Pygmies (67.5% compared with 22.0%) and males of the 2 groups were more frequently infected than females. Microfilarial load was also higher in Pygmies than in Bantus (mean microfilarial densities (MfD 50) 13 and 2 respectively). In the Pygmy group, MfD 50 for M. perstans increased with age whereas it remained stable in the Bantus. 53.8% of the 249 questioned persons had experienced worm migration under the conjunctiva. Both ethnic groups were equally exposed to the vectors of L. loa and reasons for the difference in prevalence of microfilaria carriers are discussed. For mansonelliasis increased contact with vectors may explain the higher degree of infestation observed in Pygmies. Other filariases were infrequent in (Mansonella streptocerca), or absent from (Onchocerca volvulus and Wuchereria bancrofti), the study area.
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PMID:Loa loa and Mansonella perstans filariasis in the Chaillu mountains, Congo: parasitological prevalence. 261 7

Human filarial infections afflict over 150 million persons worldwide and are major causes of morbidity in many developing countries. Onchocerca volvulus infection is a leading preventable cause of blindness, while bancroftian and brugian filariasis may produce lymphatic obstruction of the genitalia and extremities (elephantiasis). Definitive diagnosis of these helminthic infections currently depends on demonstration of microfilariae in host tissues, i.e., the skin in the case of O. volvulus and the bloodstream in the cases of Wuchereria bancrofti and Brugia malayi. Many investigations are now directed at developing specific and sensitive serum antigen assays that will allow diagnosis of active infection (i.e., presence of adult-stage parasites) in the absence of detectable microfilariae. With respect to the immunology of these parasitic infections, efforts are being directed at elucidating the role of T- and B-cell responses in the development of pathologic lesions and resistance to reinfection. These data as well as molecular biologic approaches to identify and study filarial molecules which are immunogenic are discussed. Finally, since treatment of filariases at present depends on antiparasitic drugs, the clinical indications and dosages of diethylcarbamazine and ivermectin are summarized.
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PMID:Clinical and laboratory aspects of filariasis. 264 23

Infestation with organisms causing lymphatic filariasis (i.e. Wuchereria bancrofti and Brugia malayi) results in a variety of clinical presentations. It is possible that some of the variation is due to differences in host response to parasite. To determine whether individuals who live in an endemic area but differ in their clinical manifestations respond to different filarial antigens, we screened Onchocerca volvulus expression libraries with sera from a number of individuals belonging to different clinical groups. The results of the study demonstrate that there are indeed differences in the recognition of three cloned filarial antigens and that this differential recognition is related to clinical symptomatology. The most striking finding is that an Onchocerca volvulus protein homologous to the 70 kDa Xenopus laevis heat shock protein is primarily recognized by individuals who are amicrofilaremic. Further analysis is required to determine whether these antigens play any role in the pathogenesis of filarial infection or have any potential value in protective immunity.
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PMID:Onchocerca volvulus heat shock protein 70 is a major immunogen in amicrofilaremic individuals from a filariasis-endemic area. 270 88

Administration of ivermectin (Mectizan) in Loa loa filariasis induces a significant decrease of microfilaria load within 3 to 15 days. The excellent tolerability of the drug in patients infested simultaneously by O. volvulus and Loa loa allows to use ivermectin in mass treatments in geographical areas where the same patients can be affected by several filariasis. There is almost no efficacy against Mansonella perstans. A second administration one month after the first one in Loa loa affected patients has not led to a complete disappearance of microfilaria; the tolerability has still been good. Efficacy on Ascaris lumbricoides appears to be excellent; further studies are necessary in the cases of trichuriasis, ancylostomiasis and strongyloidiasis.
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PMID:[The efficacy and tolerance of ivermectin (Mectizan) prescribed for the patient with multiple filarial infections (Loa loa/Onchocerca and/or M. perstans)]. 274 19

Microfilaria of Onchocerca volvulus are localized in superficial dermis. However, they are sometimes noticed in the blood and urines, when there is an important infestation. Diethylcarbamazine (DEC) bring on an increase of microfilaria, successively in the blood and after, in the urines. This study of 30 patients, treated in double blind by placebo, DEC and ivermectin, a new molecule with spectacular action on this filariasis, allowed to compare effect of each one on apparition of microfilariae in the blood and urines. Ivermectin bring on very important increase of microfilaremia without microfilaruria, unlike diethylcarbamazine. This establishment bring to discuss very different physiologic mechanisms between them. It should have an incidence on diagnosis and treatment of this dangerous parasite.
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PMID:[Effects of diethylcarbamazine and ivermectin on the mobilization of microfilariae of Onchocerca volvulus]. 279 92

In a cross-sectional, epidemiological and parasitological study of human filariasis, 845 individuals were examined in settlements along the Igwun Basin, Imo State, Nigeria. Four different filarial nematode species were identified. Two hundred and fifty-six (30.3%) of the individuals examined were positive for Onchocerca volvulus, 113 (13.4%) for Mansonella perstans, 76 (9.6%) for Wuchereria bancrofti and 77 (9.1%) for Loa loa. Microfilarial rates increased with age of individuals and showed a tendency towards higher prevalence rates in males than in females. The intensity of O. volvulus infection was high, with the highest microfilarial density of 44 mf mg-1 snip which occurred in the 40-49-year-old individuals. In W. bancrofti and L. loa infections, infections of over 1000 mf 20 ml-1 blood were recorded in 15.8% and 19.5% of individuals, respectively. Observed clinical signs were associated with inflammatory, lympho-obstructive and ocular manifestations. In M. perstans infections all clinical cases were inflammatory. In W. bancrofti, 44.4% of clinical cases were inflammatory, and lympho-obstructive manifestations consisted of 23.8% chyluria, 12.7% hydrocele and 19.1% elephantiasis. In L. loa infections all clinical cases were inflammatory with indications of Calabar swellings. In O. volvulus infections 23.5% of clinical cases were inflammatory, while 76.5% showed ocular manifestations. The absence of blindness despite high O. volvulus infection rates was remarkable. The presence of potential insect vectors and the occurrence of clinical signs are indications of active transmissions.
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PMID:Filariasis in the Igwun River Basin, Nigeria: an epidemiological and clinical study with a note on the vectors. 304 31


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