White piedra and Trichosporon species in equatorial Africa. III. Identification of Trichosporon species by slide agglutination test

Fifty-two Trichosporon strains isolated from Gabonese female patients 15-60 years, were studied. The identity of these strains was established by two different methods: the method proposed by Guého et al. (1992), based on mycological criteria, and a slide agglutination method performed with monospecific antisera prepared in our laboratory. The final results show a perfect correlation between the two methods, which allowed us to identify 25 strains of T. mucoides, 21 strains of T. inkin and seven strains of T. asahii. The results of the agglutination tests performed with 24-h-old subcultures grown on Sabouraud glucose agar are available in less than 15 mins. In the light of these results, it appears that this method, which is rapid and easy to perform and reproduce, may readily be used in hospital laboratories. In addition, this method allowed us to verify the presence of antigens common to the genera Cryptococcus and Trichosporon, which were easily shown by the use of crude sera. The fact that the anti-Trichosporon monospecific sera lose their capacity to agglutinate Cryptococcus neoformans proves their high specificity.

White piedra and Trichosporon species in equatorial Africa. I. History and clinical aspects: an analysis of 449 superficial inguinal specimens

White piedra is a hair infection characterized by nodules composed of fungal elements which envelop the hair shaft. Classically, this infection was considered to be produced by an asexual yeast-like fungus, Trichosporon beigelii. At present, in accordance with studies carried out previously, this species is subdivided into six newly defined distinct species (T. asahii, T. ovoides, T. inkin, T. mucoides, T. asteroides and T. cutaneum), all belonging to the class Basidiomycetes. Although widespread, white piedra has not previously been described in tropical regions of Africa. The present study, carried out in Libreville (Gabon), an equatorial region of Africa, shows that the incidence of this infection is quite high (18% of 449 inguinal specimens) in the female population aged 15-60 years, with a predominance in young patients (15-44 years). The relationship between the clinical manifestations and the specific hair lesions is also detailed. Three species belonging to the genus Trichosporon were identified: T. mucoides, T. asahii and T. inkin.

White piedra and Trichosporon species in equatorial Africa. II. Clinical and mycological associations: an analysis of 449 superficial inguinal specimens

Eighty-one of 449 Gabonese female patients examined were found to be positive for genitopubic white piedra. The association with trichobacteriosis is frequent (53 cases), and mostly seen with inguinal intertrigo. Fifty-two strains belonging to the genus Trichosporon were isolated from genital hairs as well as from inguinal intertrigo lesions. These strains were identified in accordance with previously defined morphological and biochemical criteria. Three species were recognized: T. mucoides (25 strains), T. inkin (20 strains) and T. asahii (seven strains). Their macroscopic and microscopic morphological properties, as well as their ability to reduce tetrazolium, were determined. In addition, the study of the clinical and pathogenic associations in which each of these strains was involved revealed some of their particular properties.

[Evaluation of 3 tests applied in the immunological diagnosis of hepatic amebiasis in Gabon]

The diagnosis of hepatic amoebiasis is not always easy. In case of suspicion of hepatic amoebiasis in an endemic area, the patient is immediately treated with a 5-nitroimidazole. Immunological diagnosis is indispensable. After a comparative study of BLA, IHA and IFA reactions, the BLA test has shown to be well adapted to the context of a country with insufficient sanitary infrastructure. The BLA test is easily performed and enables rapid detection of antibodies. The result obtained in about 5 minutes allows to adjust the therapeutic conduct.

Elevated antifilarial IgG4 antibody levels in microfilaremic and microfilaridermic Gabonese adults and children

Immunologic analyses of sera from 47 selected individuals living in a mixed filariasis transmission zone in Gabon were carried out. Onchocerca volvulus, Loa loa, Mansonella streptocerca, and M. perstans are transmitted in this region. Based on parasitologic findings and age, the 47 individuals were stratified into four groups: microfilaria negative (Mf-) children (3-15 years old), Mf- adults (> 15 years old), microfilaria positive (Mf+) children and Mf+ adults. For descriptive purposes, the term microfilaria positive refers to individuals with skin and blood microfilariae. Antifilarial antibody titers were determined using an enzyme-linked immunosorbent assay with Dipetalonema viteae antigens. In general, children had higher titers of IgG antibodies than adults. For the IgG1, IgG2, and IgG3 subclass responses, both age and microfilarial status appeared to be important variables since Mf- children consistently had the highest titers whereas Mf- adults had the lowest titers. For the IgG4 antifilarial response, only the microfilarial status was an important variable. All Mf+ individuals had significantly higher levels of IgG4 antibody than Mf- individuals. Pooled sera of Mf- and Mf+ individuals reacted with similar O. volvulus antigens on Western blots. Control sera of individuals who did not reside in the study area, but who had single infections with L. loa or M. perstans, did not react with any O. volvulus antigens.

[Bilharziasis caused by Schistosoma intercalatum, a recent and forgotten form of schistosomiasis]

Schistosoma intercalatum schistosomiasis is confined to the western regions of equatorial Africa. It is often asymptomatic but it produces microscopic lesions in the intestine (mainly the rectum), the liver and the genital organs of both men and women, the latter lesions being more insidious and insufficiently explored. Its treatment, like that of other schistosomiases, consists of one course of praziquantel. Naturally, S. intercalatum may be hybridized with S. haematobium in Gabon and Cameroun which are the two countries where the two parasites coexist.

[Seroepidemiological study of toxoplasmosis in Libreville, Gabon]

A sero-epidemiological survey of toxoplasmosis has been carried out in 1178 subjects residing in urban and suburban areas of Libreville, Gabon. Two techniques were used: Pastorex toxo of the Institut Pasteur and ISAGA of bioMérieux. The acquisition of antibodies occurs at an early age, from the age of six months on. After the age of 15 years, the age of procreation, the prevalence is 68%. Between the ages of 15 and 19 years, 19% have IgM. The risk for toxoplasmosis acquired during pregnancy is not to be neglected. It decreases between the ages of 20 and 30 years. The most probable source of contamination is the reservoir from the soil. No difference between the sexes was observed.

Successful treatment of acute fascioliasis with bithionol

Fascioliasis is the parasitic infestation of the liver and biliary tract related to Fasciola hepatica. Bithionol is proposed as the treatment of choice for human fascioliasis without major side effects. However, the efficacy of bithionol has been evaluated in chronic but not in acute fascioliasis. In this study we report on the success of treatment with bithionol in 10 patients with fascioliasis, 8 having acute fascioliasis. The criteria for the diagnosis of fascioliasis were hypereosinophilia, positive immunoelectrophoresis and indirect hemagglutination. Bithionol was given orally to hospitalized patients at the daily dose of 25 mg/kg body wt for 10 days. Three patients with acute fascioliasis received a second course of bithionol 2 or 3 mo after the first because of the recurrence of diarrhea and fatigue in one patient and persistent hypereosinophilia in two patients. All patients were cured. The follow-up period after the first course of treatment was between 16 and 47 mo. No major side effects were observed. We conclude that bithionol is the drug of choice for both acute and chronic fascioliasis. Moreover, its oral administration may allow treatment of fascioliasis in outpatients who do not have serious symptoms.

[Anti-nuclear factor and anti-toxoplasma antibodies detected using the Toxo-M Abbott kit]

The antibody capture IgM Toxo Abbott is a specific method. But serum specimens had false positive results. These serum specimens have been studied. There was no Forssman antibodies, no rheumatoid factors. The IgM level was normal but for some of them there were antinuclear antibodies and natural agglutinins. To interfare the assay, the antinuclear antibodies have to be IgM.

Alzheimer's disease as a capillary dementia

In addition to the well known structural stigmata which accompany the senile dementia of Alzheimer, attention is called to the presence of a group of robust changes which affect the fine vessels (capillaries, capillary arterioles and capillary venules), particularly of the cerebral cortex. These alterations include irregular pouches and excrescences on the vessels (a "lumpy-bumby" appearance), general thickening of the basement membrane, loss of the fine perivascular neuronal plexus which seems to invest each vessel, no matter how small, and the appearance of pits or lacunae in the vessel walls of about one half of the Alzheimer patients studied. None of these changes have been seen in a group of approximately age-matched, non-demented controls. Much of this perivascular neural plexus originates within a few specific subcortical fields, especially the locus ceruleus and the nucleus basalis of Meynert and basal forebrain area. These also happen to be included among those brain areas which experience the most marked neuronal atrophy or loss in Alzheimer's disease. Since there is some evidence suggesting that surgically induced vascular denervation in myocardium produces dramatic changes in vascular wall structure we wonder whether neuronal pathology developing initially in these subcortical areas may not play a significant role in the development of the characteristic neuropathology in Alzheimer's disease. These speculations emphasize the possible importance of a failing blood brain barrier in the development of the disease.

[Treatment of bilharziasis due to Schistosoma mekongi with praziquantel]

After a review of the mechanisms of anti-schistosomal activity of praziquantel and the treatment of Schistosoma mekongi with this drug, the authors report two cases of Schistosoma mekongi treated with praziquantel with failure. Rectal mucosa biopsies are performed and eggs are present. Light microscopic, electron microscopic and on ultra-thin sections examination of these samples don't reveal morphological alterations of Schistosoma mekongi eggs after treatment.

[Schistosoma mekongi bilharziasis along the Mekong River and its affluents, the Mun and Tonle Sap Rivers. General review]

First cases of Schistosomiasis in the South East Asian were described 30 years ago but the existence of a particular species in this area: Schistosoma mekongi has been discussed for a long time. During the last few years, emigration of Laotian and Cambodian people allowed a better knowledge of this affection. Through recent literature the authors make a restatement of the epidemiology, biology and treatment of this disease.

[A new molecule in antiparasitic therapy: alpha-difluoromethylornithine]

Alpha-difluoromethylornithine (DFMO) is a specific irreversible inhibitor of ornithine-decarboxylase (ODC), key enzyme in the biosynthesis of polyamines, physiological compounds involved in cell multiplication. Pharmacokinetic studies of the drug revealed good oral absorption, low metabolisation and mainly urinary excretion. Short half-life (3 hrs to 3 hrs 30) implicates daily repeated administrations. DFMO is well tolerated, side effects being reversible on discontinuing drug therapy. They chiefly include diarrheas, hematological perturbations (thrombocytopenia) and hear losses (high dosages). Experimental studies show best results on trypanosomes: curative action in mice infected with Trypanosoma brucei brucei. DFMO is effective too against infection with sporozoïtes of Plasmodium berghei. Early clinical observations in African patients with Trypanosoma brucei gambiense sleeping sickness show favorable results: efficacy in both stages of the disease, without significant toxicity. Further trials are required to define optimal therapeutic applications. By the way, DFMO already seems to be a promising alternative to conventional therapy of African trypanosomiasis, expecting other indications in the field of antiparasitic chemotherapy.

[Serological study of toxoplasmosis and echinococcosis in cattle breeders and abattoir personnel in Benin]

In Benin, a serological study of toxoplasmosis and hydatid disease has been effected among bovine stock-breeders and the staff of the slaughter-houses in comparison with a sample of blood donors. Our results reveal the highest rate of toxoplasmosis infection (87%) among the staff of the slaughter-houses, whereas the bovine stock-breeders are the most exposed population to hydatid disease with a 9% prevalence. There is no mention of similar works in Benin in medical literature.

Denervation microangiopathy in senile dementia, Alzheimer type

Structural analysis of the capillary plexus in the brains of 5 patients with clinical and neuropathological diagnosis of Senile Dementia, Alzheimer Type, revealed a group of striking physical alterations compared with tissue specimens from 5 age-matched controls. Capillary walls were thickened with irregular lumpy, nodulated contours which appeared due, in part, to infiltration of the vascular wall with rounded cell-like bodies. In some cases, these resembled the perikarya of pericytes or monocytes, or their protoplasmic extensions, which were often filled with lipids. In each case, there was no trace of the perivascular neural plexus which regularly invests the microvasculature of the brain parenchyma. The loss of this neural plexus, believed to originate largely from locus ceruleus and the basal forebrain, may be related to the changes in capillary wall structure, and these, in turn, may lead to profound alterations in blood-brain barrier function. We suggest that this subcortically induced denervation microangiopathy may serve as a pathogenic factor in the development of SDAT.

[Irregular anti-P1 allo-antibodies and sinensis clonorchiasis]

A parasitological and immuno-hematological study was undertaken simultaneously in fifty South-East asian refugees at the time of their arrival in France. --in this series the frequency of individuals having a P2 erythrocyte phenotype is 80%. --54 % of these immigrants were found to be carriers of Clonorchis sinensis, a parasite rarely found in Europe. --in 40,7 % of these subjects infested by Clonorchis sinensis, the following properties were disclosed concerning the P1 allo-antibody: slow-P1 red cell agglutination at 22 degrees C, no hemolysis of P1 red cells in vitro, IgM antibody, in weak titers. The immuno-hematological study of the immuno-serums with respect to distomian antigens coupled with adsorption-elution using P1+++ red cells shows a close immunological relationship between the antibody of parasite origin and the anti-P1 allo-antibody.

[Experimental Schistosoma mansoni parasitosis in golden hamsters. Effects on the intensity of parasitism, and on the rate of antibodies' circulation, after administration of estrogen, testosterone, or progesterone (author's transl)]

A reduction in the intensity of parasitism under the effect of an implantation of 20 mg of estradiol is observed again but such result is also obtained with testostérone administered in the same way and at the same dose. On the other hand, no significant variation in the number of parasites was observed in animals having received an implantation of 20 mg of progesterone. However, serological examinations showed that the animals treated with one of these hormones all have a specific antibody level higher than the untreated control group. Finally, it is impossible to establish a relationship between level of serum antibodies and the number of parasites.

[About eosinophilic infiltration in cellular tissue (author's transl)]

With this paper, we want to settle the part of eosinophilia in the definition of diseases as entities. Consequently, we emphasize the contribution of eosinophils in the histological diagnosis. Eosinophilic infiltration is the main marker of several lesions. We review successively some of these entities. They belong to tumoral or inflammatory (without or with vasculitis) pathology. The function of eosinophils must improve our knowledge about the significance of all these lesions (parasitic infestation, hypersensitivity...). These physiopathological mechanisms must be helpful to draw some new borders between these different entities.

[A parasitologic survey conducted in Touraine (France) in a group of South East Asia refugees (author's transl)]

Forty refugees (23 from 5 lao families and 17 from 3 cambodian families) previously and routinely treated against intestinal parasites, underwent stools and serum controls: 77 p. 100 had still intestinal parasites but 61 p. 100 had a normal blood cells count without hypereosinophilia. The parasites so detected were: Clonorchis sinensis, Heterophyes heterophyes, Trichuris trichiura, Necator americanus, Strongyloides stercoralis, Giardia intestinals and Entamoeba coli.

[Transfusional malaria. Another case (author's transl)]

Transfusional malaria is an unusual disease. Any fever, happening immediately after blood transfusions must evoke this diagnosis, confirmed by parasites detection in the blood. The treatment is rapidly efficacious. The prophylaxis is at the present time insufficient and would require fluorescent antibody test generalization.