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)

Live microfilariae of the Cameroon forest and Sudan-savanna strains of Onchocerca volvulus were inoculated into the vitreous or into the subretinal layers of the eyes of rabbits. The lesions produced are described, and are compared with those seen in control animals, which had received inocula of microfilariae-free saline supernate introduced with a similar degree of operative trauma. Control rabbits showed only minor pigment disturbance in the retina and choroid, near the healed operation scars. Infected animals showed evidence of an inflammatory process in the eye, lasting for up to 4 weeks. Fundus lesions developed following inoculation of microfilariae into the vitreous, but they were more frequent and more severe following subretinal inoculation. The lesions produced were: pallor, vascular narrowing, and flattening of the optic disc; subretinal inflammatory exudate, giving rise to a disturbance of pigment in the retinal pigment epithelium; scattered, small choroidoretinal scars, and larger circumscribed areas of choroidoretinitis, sometimes accompanied by optic atrophy. In many eyes inoculated with microfilariae the wincing reflex was lost, indicating some visual impairment. Many of the lesions were similar to those seen in human patients with onchocerciasis, but they developed much more rapidly. Microfilariae inoculated intravenously, or into the periocular tissues, were not observed to penetrate into the eye-ball.
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PMID:Fundus lesions in the rabbit eye following inoculation of onchocerca volvulus microfilariae into the posterior segment. I. The clinical picture. 125 39

The full length cDNA of the immunodominant Ov33 protein of Onchocerca volvulus was expressed in E. coli using various vector constructs. Expression was best with the vectors pGEX2T and pCG808fx, yielding fusion protein Ov33-GST and Ov33-MBP, respectively. Purified fusion protein Ov33-GST and O. volvulus antigen extracts (OvAg) were used to compare antibody responses (IgM and IgG-subclasses) of patients infected with O. volvulus, Brugia malayi, Wuchereria bancrofti, Mansonella perstans/Loa loa and of Sudanese control sera. Sera of all groups contained IgM reacting with Ov33-GST and with OvAg. There was no IgG1 response to Ov33-GST. IgG1 responses to OvAg were only detected in filariasis sera. IgG2 and IgG3 responses were not detectable or marginal in all groups. The IgG4 reaction of onchocerciasis patients to Ov33-GST and to OvAg was high, whereas few other filariasis sera contained IgG4 antibodies to Ov33-GST and to OvAg. A serodiagnostic test for onchocerciasis based on detection of IgG4 to Ov33-GST had a sensitivity of 93.3% and a specificity of 96%. An epitope common to Ov33 and to the homologous proteins of other filarial species was demonstrated with a monoclonal antibody. Purified Ov33-MBP fusion protein was used to follow the development of the antibody response of four chimpanzees experimentally infected with O. volvulus. The data indicates that antibodies to Ov33 are induced by developing worms and later parasite stages.
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PMID:Specific and sensitive IgG4 immunodiagnosis of onchocerciasis with a recombinant 33 kD Onchocerca volvulus protein (Ov33). 128 26

Male and female residents on a Guatemalan coffee plantation where Onchocerca volvulus infections were hyperendemic were offered oral ivermectin (100-200 micrograms/kg) as part of a community-wide treatment programme for onchocerciasis. Forty-five persons were treated and then questioned daily for 28 d about changes in their health. Those with complaints were monitored until all signs and symptoms had resolved. Sixty-seven percent complained of some adverse event after treatment; 60% developed observable adverse reactions attributed clinically to ivermectin. No reaction was life-threatening; the most common were oedema (53%) and fever (47%). Expulsion of intestinal helminths was reported by 38%. Almost all reactions began 24-48 h after treatment; their mean duration was 5 d, despite treatment with acetaminophen and antihistamines. Three patients had oedematous changes lasting over 2 weeks. Incidence, but not severity, of reactions was related to the pretreatment density of microfilariae in skin.
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PMID:Adverse reactions after community treatment of onchocerciasis with ivermectin in Guatemala. 128 39

The effects of single and multiple doses of ivermectin on mortality and morphology were assessed in over 700 female Onchocerca volvulus worms and the effects on embryogenesis were assessed in 490. Nodules were surgically removed from Sierra Leoneans recruited from a double-blind placebo controlled study of ivermectin given at six-monthly intervals. Nodules were digested in collagenase to isolate whole adult worms. After four or five doses of ivermectin there were significant increases in the numbers of discoloured and calcified worms and possibly a trend towards increased mortality, but this was not seen consistently. There was no evidence of a prophylactic effect of the drug. Worms were then homogenised and embryograms constructed. A single dose of ivermectin produced large numbers of degenerating intrauterine microfilariae, but embryonic development occurred normally. After multiple doses we observed almost complete cessation of embryogenesis, with a highly significant decrease in the numbers of viable multicellular embryonic stages, while oocytes appeared to be produced normally. Development is probably impeded at the single cell stage, possibly because of reduced fertilization. In planning the future role of ivermectin as a control measure for onchocerciasis it is crucial to determine if these effects on embryogenesis are reversible.
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PMID:The effect of repeated doses of ivermectin on adult female Onchocerca volvulus in Sierra Leone. 129 32

In areas endemic for onchocerciasis, active community-based treatment with ivermectin is preferred to individual diagnosis and treatment. Ideally, all infected persons should be treated, although initially priorities may have to be set at local or national levels. We suggest that all communities with a prevalence of O. volvulus infection of 20% or more in adult males aged 20 years or over should be treated; and that elsewhere facilities for passive treatment should be provided. In some areas, for logistical reasons, treatment may first have to be started in communities with the highest prevalences (perhaps above 40% or even 60%) and then expanded to all endemic communities. The available data suggest that a rapid assessment method based on the examination for nodules will give a simple, acceptable, non-invasive and reasonably reliable method of identifying the communities that should be treated. If a nodule is detected in at least three men from a sample of 30 men aged 20 years or over, the community can be assumed to have a true prevalence of infection of 20% or more and should be included in community-based treatment.
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PMID:The selection of communities for treatment of onchocerciasis with ivermectin. 129 34

An investigation of human infection with Onchocerca volvulus and the resulting clinical disease was carried out for the Nigerian National Onchocerciasis Control Programme between July and August 1989 [corrected]. The survey covered 10.6% of the rural population in 41 savanna villages of central Nigeria. Of the 8451 self-selected individuals examined, 900 (10.6%) had skin microfilariae (Mf). There were differences between villages in both endemicity and intensity of infection, but in general the number of both Mf carriers and cases of clinical onchocerciasis increased with age. The disease in the Mf carriers showed as blindness (0.8%), onchocercal nodules (0.6%), leopard skin (1.6%) and pruritus (2.8%). Of 35 persons with lymphatic complications, 19 had hanging groin, 10 had elephantiasis and six had hydrocoele. Onchocerciasis was mesoendemic in the rocky northern escarpments, and became hypoendemic and sporadic in the southern uplands of sedimentary geological origin.
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PMID:Human onchocerciasis in the lower Jos Plateau, central Nigeria: the prevalence, geographical distribution and epidemiology in Akwanga and Lafia local government areas. 130 6

The onchocercoma or nodule produced by the nematode Onchocerca volvulus (Filarioidea) in the skin of patients suffering from onchocerciasis has not been examined by histochemical techniques. In this work we have used histochemical techniques to evaluate 5 hydrolytic enzymes, namely phosphatases, esterases and beta-glucuronidase. The results show increased enzymatic activity at the sites of major metabolic activity and within reactive cells including macrophages (mc) and giant cells (gc) of the onchocercoma.
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PMID:Hydrolytic activity of an onchocercoma. 134 36

In 1989-90, health workers surveyed 2876 persons from 14 communities in the northern part of the Taraba River valley in the northeastern Taraba State of Nigeria to determine the prevalence and magnitude of eye involvement in respect to the rate and intensity of Onchocerca volvulus, the etiologic agent of onchocerciasis. 11.8% of the population were blind. Only 1 village did not have anyone who was blind (Mayoselbe). The village of Bobi had the highest blindness rate (71.9%). 20% of the population in all 6 hyperendemic communities were blind. 16.%% of all people suffered from impaired vision, the rates for which varied from 0.6 in Mayoselbe and 42.1% in Gangumi. 8.7% of the population suffered from sclerosis and 6.9% from opacity. All types of visual involvement of 0. Volvulus increased with age. Only 21.8% of =or 50 year old males and 25.2% of same age females had normal vision compared with 90.2% and 97.7% of =or 9 year olds, respectively. Sclerosis and impaired vision were most common in adolescents and blindness and opacity were most common in adults =or 30 years old. Overall there were no differences in eye involvement between males and females. Microfilarial load was significantly related to level of vision and presence of eye lesion (p.01). Blindness and opacity were more prevalent in people with 100 microfilariae/skin snip (MF/SS). Impaired vision and scerlosis tended to occur in people with 50 MF/SS. These results confirmed that the Taraba River valley is the country's worst foci of onchocerciasis and perhaps even the worst in West Africa. They indicated the need for mass distribution in ivermectin soon to prevent land depletion and increase income from optimum use of the fertile land.
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PMID:Eye lesions, blindness and visual impairment in the Taraba river valley, Nigeria and their relation to onchocercal microfilariae in skin. 135 32

Degrees of itching were estimated before and for 6 months after a fourth dose of ivermectin or placebo was given to 97 subjects in Sierra Leone. There was no reduction in itching attributable to ivermectin at any stage, but there were non-significant increases in the prevalence, severity and localization of itching within the first 2 months after ivermectin compared to placebo. We also found that cell-mediated immune responses to Onchocerca volvulus were significantly increased 4 weeks after a single dose of ivermectin compared to before treatment. A temporary reversal of the state of immunosuppression in people with onchocerciasis may counterbalance the reduction in skin microfilarial loads following ivermectin, with no consequent reduction in itching. The lack of effect of ivermectin on itching, a major symptom of onchocerciasis, while disappointing, need not detract from the success of mass distribution programmes.
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PMID:Ivermectin does not reduce the burden of itching in an onchocerciasis endemic community. 141 53

The diagnostic potential of musculo-skeletal pain (MSP) in the rapid assessment of onchocerciasis of morbidity and of the impact of ivermectin treatment in a community is brought to picture. The clinical impression is that MSP is a common, early, chronic important symptom of onchocerciasis. With a significant association with onchocerciasis, MSP has the potential of being an important operational diagnostic clue in the detection of onchocerciasis. It has the advantage of being easily recognizable, and therefore can be applied by primary health care workers. MPS is proved to cause the greatest morbidity, particularly among working farmers in areas where the forest strain of O. volvulus is predominant. Thus, onchocerciasis is contributing more than was perhaps realized to the reduced output of work from farmers. However, MPS, a parasitic rheumatism, is proved to be eminently susceptible to treatment by DEC.
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PMID:Musculo-skeletal pain (MSP) in onchocerciasis: a potential in the rapid low cost epidemiological survey and in the assessment of impact of ivermectin treatment on a community. 141 18


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