[Immunofluorescence reaction of antibodies directed against the intestinal epithelium of Schistosoma mansoni. VI. Immunolocalization of a carbohydrate epitope at different developmental stages]. / Etude par la réaction d'immunofluorescence des anticorps dirigés contre l'épithélium intestinal de Schistosoma mansoni. VI. Immunolocalisation d'un épitope glucidique aux différents stades évolutifs.

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. The epitope appears to be located on the peripheral membranes of the adult worm, while it is produced by the alive miracidium in the eggs located in the tissues and subsequently spread out inside the periovular granuloma. Moreover, in adult worms, the observed structure presents itself as a soluble form in organic solvents; on the other hand, in eggs, the epitope was essentially found made of an hydrosoluble substance. These datas can explain why, in experimentally infected mice, the epitope is mainly determined in urines at the sixth week of infestation, when eggs are settled down in the tissues. Besides, the inhibition of the monoclonal antibody fixation by a pentose which contains the Lewis X antigen, painted out that the carbohydrate structure recognised by the monoclonal antibody could be the Lewis X antigen or a very closed structure.

[Epidemiology of certain endemic parasitic diseases in the town of Guadalupe (Republic of Sao Tome and Principe). II. Other endemic parasitic diseases]. / Epidémiologie de certaines endémies parasitaires dans la ville de Guadalupe (République de Saõ Tomé et Príncipe). II. Autres endémies parasitaires.

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]. / Epidémiologie de certaines endémies parasitaires dans la ville de Guadalupe (République de Saõ Tomé et Príncipe). I. Schistosomose à S. intercalatum et verminoses intestinales.

Schistosomiasis intercalatum in known to exist in Saõ Tomé since 1988, (Corachan et al.). It is transmitted by Bulinus forskalii, (Brown et al., 1989). Stool, blood and urine specimens have been collected from 380 inhabitants of all age groups living in the small town of Guadalupe close to the Agua Traz river and Agua Polino. The prevalence of schistosomiasis by detection of S. intercalatum eggs in a 10 mg stool thick smear (Kato technique) is 25.5%. An excreted Schistosoma polysaccharide antigen, detected by means of a monoclonal antibody (Ripert et al., 1992), is found in 49.1% of the urine samples. Patients voiding S. intercalatum eggs in stools have been treated with praziquantel (40 mg/kg body weight), as recommended by WHO Expert Committee on Schistosomiasis, but it might be wise to also treat persons excreting antigen in urine. The prevalence of intestinal helminthiasis, ascariasis (73.7%), trichuriasis (73.7%) and necatoriasis have been measured.

[Influence of anesthesia on the localization of Schistosoma mansoni. Intestinal schistosomiasis in white mice]. / Influence de l'anesthésie sur la localisation de Schistosoma mansoni. Cas de la bilharziose intestinale de la souris blanche.

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. A vacuum-pump was used to collect separately the parasites from the mesenteric and portal vessels and those from hepatic vessels. The parasite counts in the hepatic vessels of the mice which had received an anesthetic were compared with those found in the vessels of the control group; they were found to be significantly raised. It would appear that anesthetic agents altered the neuromuscular function of the parasite which was thus carried away towards the liver. This massive migration of the parasites would deprive the hepatic lobules of portal blood by worsening the already existing obstruction at the precapillary level caused by the schistosomiasis.

[Evaluation of an indirect hemagglutination test for the serodiagnosis of amebiasis]. / Evaluation d'un test d'hémagglutination indirecte amibiase (HAI) pour le serodiagnostic de l'amibiase.

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. While lower rates or discrepancy between the two tests may evoke an hidden infestation in patients coming out or originated from endemic zones.

[Epidemiological study of bancroftian filariasis in the Logone Valley (North Cameroon) (author's transl)]. / Etude epidémiologique de la bancroftose dans la Vallee du Logone (Nord Cameroun).

In the Logone Valley, Yagoua and the surrounding area, the prevalence of the bancroftian filariasis was measured by means of determinating the microfilarian rate: 22,1 p. 100 in males and 9,8 p. 100 in females. The immunofluorescence test on D viteae frozen sections showed the presence of antibodies in 61,5 p. 100 of the males and 68,2 p. 100 of the females. A balance between the microfilarial rate and the percentage of inhabitants with specific antibodies was observed. Parasitological and immunological examinations appeared to be complementary. The microfilarial density is 19 microfilariae/20 microliter of blood in males and 13 microfilarae/20 microliter in females. Elephantoid extremities of scrota was observed in 13,2 p. 100 of the adult males, all of them having more than 40 years of age. Females are less affected than males. At the beginning of the rainy season, females of A. gambiae were the mosquitos the most frequently caught in the houses.

[Evaluation of malarial indices in the forest region of Djoum (southern Cameroon)]. / Evaluation des indices paludométriques dans la région forestière de Djoum (Sud Cameroun).

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.

[Epidemiologic study of intestinal and urinary bilharziasis in the Tala Mokolo region (Mandara Mountains, North Cameroon)]. / Etude épidemiologique des bilharzioses intestinale et urinaire dans la région de Tala Mokolo (Monts Mandara, Nord Cameroun).

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. Evaluated from hemagglutination test, bilharziosis prevalence reaches 55,7%. Male subjects are more frequently affected than female subjects, particularly as for as intestinal bilharziosis is concerned. Urinary bilharziosis prevalence or intestinal bilharziosis prevalence are subject to proximity of small water reservoirs mostly infested either by Bulinus globosus or Biomphalaria pfeifferi. These small water reservoirs are mainly "mayo" head-bays.

[Malaria indices, larval ecology and trophic activity of Anopheles mosquitoes in Djohong (Adamaoua, Cameroon) in the rainy season]. / Indices paludométriques, écologie larvaire et activité trophique des anophèles à Djohong (Adamaoua, Cameroun) en saison des pluies.

In Djohong in the wet season the prevalence of malaria is 17.5% for Plasmodium falciparum and 1.1% for Plasmodium malariae. In children 2 to 9 years of age the plasmodic index is 38.6% (mesoendemicity) for the children of the peasants and 9.4% for those belonging to other socioeconomical groups. In infants less than 12 months old, the plasmodic index is 9.3%, this relatively high rate corresponding to the high transmission period of the rainy season. Anopheles gambiae is the mosquito species most often found in the area (2/3 of the mosquitoes caught in the houses). The breeding sites in he surrounding of the houses are rainwater holes linked to human activity. At a larger distance from the houses, in the valley, the breeding sites are water holes borrowed for the retting of cassava tubercle or natural rock pools found in the basaltic shores of the Mbere river. The trophic activity of Anopheles gambiae and Anopheles funestus is high between 0 and 4 hours a.m. In October the mean number of anopheline mosquitoes bites per night per inhabitant is 33 inside the houses and 7 outside.

[Epidemiological aspects of malaria in 2 villages of the Manyemen forest region (Cameroon, southwest province)]. / Aspects épidémiologiques du paludisme dans deux villages de la région forestière de Manyemen (Cameroun-province du Sud-ouest).

In terms of parasitaemia in blood, the prevalence was 18.7% for Plasmodium falciparum, 10.5% for P. ovale and 1% for P. malariae in the villages of Mungo Ndor and Kokobuma. The plasmodial index of children from 2 to 9 years of age was 38.2% and the spleen index 26.6%, with a mean HACKETT score of 1.56. Malaria is thus meso-endemic in the region. The immunofluorescent test performed with a P. falciparum antigen was positive in 66% of the children in the same age group. Parasites were seen in 15% of new-born children. The malaria infection indices were higher in Mungo Ndor, which is located on the main road in the vicinity of the Manyemen hospital, than in Kokobuma. Morbidity and mortality due to malaria remain major problems in this part of the South-West Province, in spite of improving primary health care facilities and free chloroquine distribution. Anopheles gambiae is the main vector of malaria in the area, and transmission is interrupted only during the short dry season.

[Epidemiologic study of malaria in the Koza region (North Cameroon)]. / Etude épidémiologique du paludisme dans la région de Koza (Nord Cameroun).

The data obtained in the survey carried out in the villages of the Mandara mountains are as follows. P. falciparum is the only species of Plasmodium which has been found in the area. The parasitic rate in children 2 to 9 years of age is 40.8 p. 100 and the spleen rate 35.6 p. 100. The immunofluorescent test performed with an homologous P. falciparum antigen is positive in 37.7 p. 100 of the children of this class of age. The thick drop shows parasites in 25 p. 100 of the newborn children. The parasitic load rated by number of blood cells harboring parasites is high in young children, then diminishing in adults while the antibodies increased. Malaria cases are more numerous at the end of the rainy season but a new spell of the disease is also noticed at the beginning of the year while the outside temperature is especially high. Malaria, now mesoendemic in the study area, seems to decrease as far as parasite and spleen rates are concerned in comparison with the rates obtained in the Mandara mountains 20 years ago. This seems to be a consequence of an increase in the intake of chloroquine by the inhabitants.

[Effect of muramyldipeptide (MDP) on rat resistance to Schistosoma mansoni]. / Influence du muramyldipeptide (MDP) sur la résistance du rat vis-à-vis de Schistosoma mansoni.

Partial immunity to Schistosoma mansoni, in the rat, can be obtained by injection of a bilharzian antigen together muramyldipeptide (MDP) in a water in oil emulsion. This immunity is the result of both specific and non specific mechanisms.

[Immunofluorescent reaction of antibodies directed against antigens from the intestinal epithelium of Schistosoma mansoni. III. Study of the reactivity of monoclonal antibodies]. / Etude par la réaction d'immunofluorescence des anticorps dirigés contre les antigènes de l'épithélium intestinal de Schistosoma mansoni III--Etude de la réactivité d'un anticorps monoclonal.

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. The antigen was shown to be Schistosoma genus specific. It was found in different developmental stages of the parasite. High levels were detected in egg extracts.

[Immune phenomena during experimental schistosomiasis in the rat: role of specific and non specific factors]. / Les phénomènes d'immunité au cours de la bilharziose expérimentale chez le rat: rôle des facteurs spécifiques et non spécifiques.

Partial immunity to Schistosoma mansoni in the rat can be obtained by injection of a bilharzian antigen together with Freund's complete adjuvant. The results are the same no matter what form of the parasite is used (infecting cercariae or adult). This immunity is the result of both specific and non-specific mechanisms, as is proved by the fact that a lesser but still quite clear degree of resistance to infestation can be obtained by injection of Freund's adjuvant alone.

[Influence of reintervention by the bacillus of Calmette and Guérin (BCG) on the nonspecific resistance of the mouse to Schistosoma mansoni (author's transl)]. / Influence d'une réinfestation par le Bacille de Calmette et Guérin (BCG) sur la résistance non spécifique de la souris vis-à-vis de Schistosoma mansoni.

Significant resistance to Schistosoma mansoni appears in mice two weeks after treatment with BCG. The state of nonspecific resistance is considerably increased if the injection of BCG two weeks prior to the infestation test is carried out using mice who have already received BCG. Thus, BCG innoculation in an organism presentized to the bacillus antigens increases immunostimulation. According to these results, during primoinnoculation with BCG, immunostimulation is not significant before this second week, that is, the time necessary for a state of hypersensitivity to appear. Nevertheless, it should be noted that weak yet detectable immunostimulation can be observed before the 14th day following a BCG primoinfection. Thus, the possible role of other mechanisms should be considered.

[Effect of Bacillus Callmette Guerin (BCG) on the receptivity of nude mice to Schistosoma mansoni]. / Influence du bacille de Calmette et Guérin (BCG) sur la réceptivité de la Souris nude vis-à-vis de Schistosoma mansoni.

"Nude" mice are injected intravenously with 1 mg live BCG each. Pulmonary schistosomules, counted 5 days after infestation with Schistosoma mansoni cercaria are observed to be fewer in injected mice than in non-injected controls. This show that BCG immunostamulation can be obtained when mature T lymphocytes are absent.

[Reversibility of the effects of general anesthetics on Schistosoma mansoni]. / Réversibilité de l'action des anesthésiques généraux sur 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. No significant difference in the counts in the mice under experiment and those of control groups was noted.