Schistosoma mansoni: in vitro adhesion of parasite eggs to the vascular endothelium. Subsequent inhibition by a monoclonal antibody directed to a carbohydrate epitope.

Schistosoma mansoni eggs come into direct contact with the vascular endothelium, particularly in the postcapillary venules of the mesenteric tract (oviposition site). We investigated the adhesion of eggs to endothelial cells in a static in vitro assay and in a flow-based in vitro assay. Live S.

[Immunofluorescence reaction of antibodies directed against the intestinal epithelium of Schistosoma mansoni. VI. Immunolocalization of a carbohydrate epitope at different developmental stages].

In the course of previous works, we described an IgM monoclonal antibody directed to a carbohydrate epitope located on the gut epithelium surface of the Schistosoma mansoni adult worm. We provided evidence that this epitope was present in all stages of the parasite and was particularly abundant in eggs. The current work was performed in order to specify the epitope localisation, at each stage, by immunohistochemical techniques.

Endothelium activation related increase of soluble intercellular adhesion molecule-1 in human schistosomiasis. Lack of correlation with serology.

Soluble intercellular adhesion molecule-1 (sICAM-1) level was measured in sera from 41 patients with Schistosoma mansoni schistosomiasis and compared with the sICAM-1 level in 41 healthy subjects. A significant increase in serum sICAM-1 was observed in patients with schistosomiasis compared with control subjects. As they were inhabitants of the French Antilles, the patients were, however, not settled in a malaria endemic zone, allowing this cause of sICAM-1 enhancement to be eliminated.

[Epidemiology of certain endemic parasitic diseases in the town of Guadalupe (Republic of Sao Tome and Principe). II. Other endemic parasitic diseases].

Stool, blood and urine specimens have been collected from 380 inhabitants of all age groups living in the small town of Guadalupe in May 1992. The seroprevalence of Falciparum malaria (96%), toxoplasmosis (73.3%), have been measured.

[Epidemiology of certain endemic parasitic diseases in the town of Guadalupe (Republic of Sao Tome and Principe) I. Schistosomiasis intercalatum and intestinal worms].

Schistosomiasis intercalatum in known to exist in Saõ Tomé since 1988, (Corachan et al.). It is transmitted by Bulinus forskalii, (Brown et al.

[Malaria indices, larval ecology and trophic activity of Anopheles mosquitoes in Djohong (Adamaoua, Cameroon) in the rainy season].

In Djohong in the wet season the prevalence of malaria is 17.5% for Plasmodium falciparum and 1.1% for Plasmodium malariae.

[Study by the immunofluorescence reaction of antibodies directed against antigens of the gut epithelium of Schistosoma mansoni. V. Modulation of granulomatous reaction around the egg under the influence of an IgM monoclonal antibody].

The periovular granulomatous reaction has been reduced in vivo by an IgM monoclonal antibody. The granulomatous reaction has been obtained either in unsensitized, or sensitized as well as immunized mouse. The granulomatous reduction could be explained by a decrease in egg viability, owing to the fact that the monoclonal antibody is lethal against an in vitro miracidium suspension.

[Evaluation of an indirect hemagglutination test for the serodiagnosis of amebiasis].

167 sera have been tested to appreciate the value of an indirect hemagglutination test (Amibiase HAI FUMOUZE) comparatively to an agglutination test of sensibilized particles of latex (Bichro latex Amibe Fumouze BLA) Amibiase HAI test comes out as sensitive and specific for the detection of antibodies in patients suffering from visceral amoebiasis. But some antibodies are also detected in patients with an antecedent of amoebiasis, as it is usually the case with some other techniques. A high positivity of the indirect hemagglutination test, and the concordance between the test HAI and the BLA one are in favour of a visceral amoebiasis.

Detection with a monoclonal antibody of a polysaccharide antigen, excreted in the urine, in the schistosomiasis intercalatum focus of Edea (Cameroon).

The detection in the urine specimens of a sample of the inhabitants of Edea of a polysaccharide antigen characteristic for the genus Schistosoma, with monoclonal antibody by means of the inhibition of a passive haemagglutination test, shows that this technique is very sensitive for measuring prevalence of schistosomiasis due to S. intercalatum. In Edea, looking for eggs in stool specimens gives a low prevalence rate of the disease because of the low parasitic load.

[Evaluation of malarial indices in the forest region of Djoum (southern Cameroon)].

The authors report the results of a sample survey carried out in Djoum to evaluate the main malarial indexes among 0-15 years old children. These investigations suggest that malaria is hyperendemic in this forestry area, at the end of the dry season.

Effect of a mass treatment with praziquantel on the excretion in urine of a polysaccharide antigen used for diagnosis of schistosomiasis due to S. mansoni in Cameroon.

The detection in urine, with a monoclonal antibody, of an excreted polysaccharide antigen characteristic of the genus Schistosoma, allows evaluation of the effect of praziquantel used for mass treatment, in a focus of S. mansoni infection. Inhibition of the passive haemagglutination test, which was used for detecting the polysaccharide antigen in urine, is more sensitive for measuring prevalence than the determination of eggs in stools by means of direct examination and the formalin-ether concentration technique.

[Study of antibodies directed against antigens of the gut epithelium of Schistosoma mansoni using an immunofluorescence reaction. IV. Blocking action on immunity of an IgM monoclonal antibody].

The inhibitory effect on immunity is demonstrated by passive transfer experiments in mice. It can be shown in a secondary infection with Schistosoma mansoni and also in primary infection. The results indicate that blocking activity probably interfers with non specific immunity mechanisms.

Detection with a monoclonal antibody of an antigen, characteristic of the genus Schistosoma, excreted in the urine.

In the host, the antigen excreted by schistosomes in the circulating blood is concentrated in the urine. A mouse monoclonal antibody of the IgM class type lambda, directed against an epitope of the intestinal epithelium of the adult worm, is obtained. The antigen found in the urine of the host as well as the monoclonal antibody has been previously characterized.

[Epidemiological aspects of malaria in 2 villages of the Manyemen forest region (Cameroon, southwest province)].

In terms of parasitaemia in blood, the prevalence was 18.7% for Plasmodium falciparum, 10.5% for P.

[Evaluation of the clinical, parasitological and immunological indices of malaria in the Bonny's Bay area of Central Africa].

The authors report the results of 4 sample surveys carried out in Equatorial Guinea and Cameroon in the Bonny's Bay area, to evaluate the main malarial indexes. In rural and semi-rural areas one notice a high rate of fever attacks and splenomegaly. Parasitaemia is more important in rural areas than in urban areas and is decreasing where the therapeutic pressure is strong and long-lasting.

[Epidemiology of filariasis (onchocerciasis and bancroftosis) in the Tala-Mokolo region (Mandara Mountains of North Cameroon)].

The effect of the bancroftian filariasis on the health of the inhabitants are minimal in the study area, where the prevalence of the disease (nocturnal microfilaremia) is 0.4% only. But skin snips harboring Onchocerca microfilariae are seen in 12.

[Serodiagnosis of schistosomiasis mansoni using an egg extract semi-purified by precipitation with ammonium sulfate].

Fifty one sera from bilharziosis patients and thirty control sera were examined with a Schistosoma mansoni egg antigen purified by precipitation with ammonium sulphate at 50% saturation. Sensitivity and specificity were good and showed a good correlation with results obtained by MSA1 antigen, but antigen tested is far more easier to prepare than MSA1.

[Immunofluorescent reaction of antibodies directed against antigens from the intestinal epithelium of Schistosoma mansoni. III. Study of the reactivity of monoclonal antibodies].

A monoclonal mouse antibody of IgM class was raised against an epitope of the gut epithelium of the adult worm and was applied to the detection of antigen in parasite infection. The antigen was found in urine from mice and hamsters infected with Schistosoma mansoni; a good correlation between the concentration of antigen and worm burden was observed. The antigen was thermostable, soluble in trichloracetic acid; it was not hydrolysed by proteinase K but it was destroyed by metaperiodate.

[Epidemiologic study of intestinal and urinary bilharziasis in the Tala Mokolo region (Mandara Mountains, North Cameroon)].

In the Mandara Mountains, where small dams have been erected, people living in the Tala Mokolo district eliminate some S. haematobium eggs in 31,4% of urines samples, and some S. mansoni eggs in 38,1% of stools samples.

[Immunofluorescence test of antibodies directed against antigens of the intestinal epithelium of Schistosoma mansoni. II. In the bilharziasis patient].

Specific IgM antibodies to antigens present in the epithelial cells of the gut of adult S. mansoni were measured in 2 230 persons living in areas of different levels of endemicity. Significant differences were found in the prevalence of IgM antibodies in the infected patients of the compared bilharziasis foci: lower prevalences were found in high endemic foci, involving the possibility of a tolerance phenomenon.

[Epidemiologic study of malaria in the rice-growing regions of Yagoua and Maga (North Cameroon)].

The results of the malaria investigation carried out in April 1981 in the irrigated regions of the Logone Valley show that Plasmodium falciparum is the only species o. the genus Plasmodium to be found there. In terms of parasitaemia in blood, the prevalence of malaria is highest in the 5 to 9 year-old age group, whereas fluorescent antibodies are to be found progressively greater quantities as subjects grow older.

[Influence of anesthesia on the localization of Schistosoma mansoni. Intestinal schistosomiasis in white mice].

General anesthetics or hypnotics (ketamine, propanidid, thiopental, althesin, halothane, enflurane, ether), were tested on white mice infested with Schistosoma mansoni to study possible changes in the migration of this trematode from the mesentery to the liver. With this in mind, populations of 25 mice of the same sex and age were chosen at random; they were divided into a control group and a group submitted to an anaesthetic agent. The mice were perfused after dissection and catheterization of the abdominal aorta.

[Reversibility of the effects of general anesthetics on Schistosoma mansoni].

In order to verify whether the migration of Schistosoma mansoni from mesenteric vessels towards the liver under the action of general anesthetics (althesin, ether, enflurane, halothane, propanidid and thiopental sodium) is reversible, 65 mice were submitted to an anaesthetic and then perfused after dissection 24 hours later. The Schistosoma counts from porto-mesenteric vessels of the mice from control groups (60 mice) were compared with those of the mice under experiment. The counts from the hepatic area of the groups were also compared.