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Biomedical subjects

Y Garin

Publications and source records attributed to Y Garin.

At least 19 recordsLinked to original sources

Rotavirus prevalence and relationships with climatological factors in Gabon, Africa.

A one-year study of rotavirus prevalence was carried out using electron microscopy in Gabon, equatorial Africa. One hundred fifty-six nonhospitalized diarrheic children up to 10 years of age and 115 age-matched controls were investigated together with diarrheic adults and children over 10 years of age. Rotaviruses were observed only in diarrheic children under 10 years of age (10.2%). Rotaviruses were more prevalent in the dry-season months (19.2% versus 1.3%, P less than .001). Rotaviruses were the most commonly found among all the viral, bacterial, and parasitic agents we detected, with the exception of the coronaviruslike particles, which are the subject of another paper [Sitbon, 1985].

Adolescent↗

Loa loa: a simple method for isolation of microfilariae from blood with production of antigen in extraction medium.

A simple method for isolating Loa loa microfilariae from the blood of patients is described. This involves sedimentation on Ficoll followed by migration of the microfilariae into an extraction medium. During migration the microfilariae release antigen-rich excretory or secretory products. The procedure thus yields two products: pure microfilariae and large amounts of antigen in the extraction medium.

Antigens, Helminth↗

Age of appearance of IgG, IgM, and IgE antibodies specific for Loa loa in Gabonese children.

IgG, IgM, and IgE antibodies against the filaria Loa loa were measured in umbilical cord blood and in blood from young Gabonese children by an ELISA technique using a homologous metabolic antigen. For children in eight consecutive age groups and adults the percentage of the population positive for each of the antibody classes was determined. The number of children with maternal IgG decreased until one year of age when new synthesis began to become apparent. IgM antibodies were detected only after six months, probably indicating an early infancy as opposed to a fetal infection. The percentage of individuals positive for IgM or IgE reached a peak between two and three years old, followed by a slight decline. Over half of the individuals over one year of age had IgM antibody against L. loa, indicating long-term synthesis of this class of immunoglobulin in many people. In the first two years of life, IgE antibodies were usually accompanied by L. loa-specific IgM. This specific IgE did not appear to trigger the synthesis of nonspecific IgE. By the age of two, 95% of the population had some antibodies against L. loa and by five the percentage of individuals positive for each antibody class had reached adult levels.

Adult↗

[Current aspects of the ELISA technic applied to the serological diagnosis of helminthiasis].

The authors reviewed the data acquired in ELISA technique for serological diagnosis of parasitosis. They reviewed the literature on Schistosomisis, Fasciolasis, Cestode infections (hydatidoses and cysticercoses) and nematode infections. They described their adaptation of the technique for detection of antimicrofilaria Loa loa antibodies and concluded that ELISA technique is reliable in the diagnosis of parasitic diseases even in areas where they are endemic.

Cestode Infections↗

Chromoblastomycosis. A morphological investigation of the host-parasite interaction.

Chromoblastomycosis is a distinct cutaneous mycotic infection. Histologically it is characterized by the presence of fungus invariably in the yeast phase and by macrophages in large numbers. The morphology of fungus in both yeast and hyphal phases and its interaction with mononuclear phagocytes were examined using ultrastructural techniques. The major structural difference between the fungus in cutaneous tissue and that from a culture medium was a striking increase in cell wall thickness in the former. In the skin, the organisms were phagocytised by macrophages and enclosed in large membrane limited intracytoplasmic vacuoles. The thick, stratified, electron-dense fungal cell wall was observed in stages of alteration of varying severity. Most common was a granular modification of the outermost layers of the cell wall in contact with the vacuolar content. Fragmentation, splitting and rupture of this and deeper layers was also seen. Several ultrastructural features suggested that cell wall damage resulted from an active host cell digestion. The cell wall changes were in sharp contrast with the usual normal fungal cytoplasmic appearance. Only rare intracellular debris which we supposed to represent dead yeast cells were found. These findings suggested that the yeast responsible for chromoblastomycosis resisted fungicidal activities of cutaneous macrophages which possessed the ultrastructural features of stimulated phagocytes.

Chromoblastomycosis↗

Placental pathologic changes in malaria. A histologic and ultrastructural study.

Placenta malarial changes (PMCs) related to maternal plasmodium infection were present in 33% (247 cases) of a series of 741 placentas collected from an unselected population living in an area of high malarial endemicity (Haut-Ogooué, Gabon, Africa). Plasmodia were found on material thick blood films taken at the time of delivery in 42% of the women with and 24% of women without associated PMCs. Plasmodium falciparum was the most frequent infecting organism. PMCs were more frequent and, in general, more marked in primiparas. The primiparas were significantly (P less than 0.001) more numerous in the group with PMCs than in the control group without such changes. The mean weight of term placentas with malarial changes was significantly (46 g; P less than 0.001) less than that of placentas without such changes. The morphologic changes were a combination of the following features: 1) presence of parasites in the intervillous spaces; 2) macrophage concentration in the intervillous spaces; 3) malarial pigment deposits; 4) excess of perivillous fibrinoid deposits; 5) syncytiotrophoblastic damage; and 6) trophoblastic basal lamina thickening. Plasmodia were found in placental intervillous spaces in 42% (105/247). Local parasitemia varied in magnitude; in a few cases, 30% or more of the maternal erythrocytes were infected. Macrophage concentration in the intervillous spaces was present in 29% (72/247) and was always associated with local parasitemia. Macrophages phagocytized red blood cells and malarial pigment, and their number varied inversely with that of the local parasites. It seems, therefore, that macrophages play an important role in local parasite clearance. Malarial brown pigment was observed in all cases from the series. It had characteristic ultrastructural features and occurred in perivillous deposits of fibrinoid, in macrophages, or free in intervillous spaces. Excessive perivillous fibrinoid deposits were a constant histologic finding and were usually associated with syncytiotrophoblastic necrosis or ultrastructural damage such as partial microvilli loss, filamentous material accumulation in intracytoplasmic vacuoles, and "podocytelike" cytoplasmic projections on the basal surface. At these sites the trophoblastic basal lamina was usually thickened. Previously reported morphologic data and our own findings suggest that the peculiar placental changes in malaria, restricted to intervillous spaces and to villous surfaces, may be related to an immunopathologic process.

Female↗

[Etiological study of low fertility in eastern Gaboon. III. Filarial endemicity (Loa loa, D. perstans). Prevalence of microfilariae in hydroceles (author's transl)].

During an inquiry performed in Gaboon the prevalence of hydroceles had led to puncture systematically every vaginal flow. 68 fluids were so collected at the end of the inquiry. Subsequently the statistical analysis of the results in men seems to suggest a correlation between microfilaremia (Loa loa and D. perstans) and the prevalence of hydroceles. Microfilariae were found in 77% according to the following distribution: Loa loa seldom diagnosed in this kind of flow were detected in 10%; D. perstans although never reported so far in hydrocele fluids appeared to be present in 62%. O. volvulus more currently referred to in hydrocele liquids were scarcely traced.

Adult↗

[Apropos of a case of myospherulosis].

The case was one of a 25-year-old woman with a polycystic subcutaneous nodule in the posterior iliac region, developing three weeks after a series of injections. Histological examination revealed the presence of cysts with a saccular formation filled with endospherules characteristic of the disorder. Myospherulosis is reviewed in the light of this first european case.

Adult↗

[Toxoplasmosis in Eastern Gabon. Results of a serologic survey].

1,448 sera taken from individuals of various places of South-Eastern Gabon have been studied by means of indirect immunofluorescence and Fulton direct agglutination associated with 2-mercapto-ethanol test, 52.6% contained antitoxiplasmic antibodies. This study showed that toxoplasmic infection occurs early in both sexes, that it is more frequent in men (57.9%) than in women (45.4%), that the Ogooué-Lolo province is more contaminated (62.6%) than the High Ogooué province (49.6%). It seems that prevalence differences are less dependent upon the telluric elimate than upon other factors, which remain to find.

Adolescent↗