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Biomedical subjects

M Giboda

Publications and source records attributed to M Giboda.

83 records · Page 5Linked to original sources

Human Opisthorchis and Haplorchis infections in Laos.

A study of the epidemiology of trematode infections was carried out in Vientiane province, Laos, comprising examination of snails, fish, cats, and human stools. Opisthorchis viverrini cercariae were found in the snail Bithynia siamensis goniomphalus (Bithyniidae) and Haplorchis taichui cercariae in Tarebia granifera (Thiaridae). O. viverrini metacercariae were recorded in the flesh of 7 species of cyprinid fish; metacercariae of the heterophyid fluke Haplorchis taichui were found in 4 species of cyprinid fish and those of H. pumilio in 2 species. Cats from the same localities were infected with O. viverrini and 4 species of heterophyid flukes, frequently as multiple infections. The highest prevalence of small fluke eggs in human stools was recorded in the 20-29 years age group, particularly in males (90.4%). Three-quarters of human infections were light (less than 1000 eggs/g), the highest value (2975 eggs/g) being recorded in the 10-14 years age group. Identification of small flukes excreted by Laotian patients after treatment with praziquantel in Czechoslovakia revealed more cases with H. taichui than with O. viverrini. The results confirmed the simultaneous occurrence of O. viverrini and intestinal heterophyid flukes in the area studied.

Adolescent↗

Impact of antifibrotic treatment of the course of Schistosoma mansoni infection in murine model.

Administration of an antifibrotic agent as an adjunct to antihelmintic treatment with the objective of morbidity reduction was investigated in the murine schistosomiasis mansoni model. Antifibrotic, beta-aminopropionitrile treatment has a profound effect on the cellular matrix composition of the liver granuloma of Schistosoma mansoni infected mice when given alone, resulting in increase macrophage infiltration. These macrophages, in response to stimulation with soluble egg antigen or lipopolysaccharide produced elevated levels of nitric oxide but low levels of tumor necrosis factor alpha compared to untreated infected mice. This also correlated with reduced liver granuloma size. In spite of low numbers of eggs in the liver, mice receiving a combine treatment had a high level of resistance to a challenge infection compared with mice receiving only praziquantel. Those mice also exhibited a reduced lymphocyte proliferative response, similar to that of infected untreated mice. Antifibrotic treatment has an impact on the dynamic of the cellular nature of granulomas and impacts on the host immunity of infection.

Aminopropionitrile↗

[The determination of the species specificity of Leishmania antibodies in different groups of human sera].

Species-specificity of two serological tests has been compared: Indirect immunofluorescence test and C-ELISA using antigens prepared of 7 Leishmania species of various groups of human sera, including sera from healthy donors; sera of patients with various tropical parasitoses; sera containing rheumatoid factor and antinuclear antibodies; sera of patients with visceral leishmaniasis (VL); sera of normal subjects arrived from regions endemic for VL; sera of students arrived in Czechoslovakia from various tropical countries endemic for leishmaniasis. It has been shown that C-ELISA (and EIA with corpuscular antigen), being highly sensitive techniques, are very promising for the identification of species-specific Leishmania antibodies. C-ELISA titres beginning from 1:800 and above may be considered as species-specific. With the titre 1:400, cross-reactions with antigens of various Leishmania species are observed.

Animals↗

[The functional characteristics of the ultrastructure of the outer membranes of opisthorchid eggs. 2. The mechanisms of egg retention on substrates].

The studies of the functional features of the ultrastructure of the outer membranes of Opisthorchis felineus and Clonorchis sinensis eggs have been continued. The variants of egg behavior on different substrates (artificial, natural, organic and inorganic) have been experimentally studied. It has been established that O. felineus and C. sinensis eggs retain on a number of substrates due to covering with microflora (e.g. fungus mycelium clinging to the rubbed surface of the egg outer membranes); sticking in the uneven surface of the substrate; catching in the uneven surface of the substrate; catching on microfibers of plant fragments. The features found are to a great extent caused by a complex comb-like structure of egg membranes and are interpreted in terms of the earlier unknown mechanisms of parasite adaptation (at the egg stage) facilitating its contact with molluscs--their intermediate hosts.

Adhesiveness↗

[The morphofunctional characteristics of the ultrastructure of the outer membrane of opisthorchid eggs. 1. The hatching of miracidia].

Some functional peculiarities of miracidia hatching from O. felineus eggs have been studied, using scanning electron microscope. The results were compared to the earlier data obtained by the method elaborated for the determination of opisthorchis eggs viability by stimulation of miracidia release in the artificial media. It is concluded that in the course of miracidia hatching the two release-stimulating factors (mechanical and chemical) are mutually complementing each other. First, the egg membrane is deformed, in which the radula of the mollusk host plays an essential role, then the process of chemical activation of the hatching gland is triggered and miracidia motor activity is stimulated. A complex comb-shaped structure of opisthorchis eggs outer membranes is associated with the necessity of long-term eggs survival in the water reservoirs and forms a light delicate carcass preventing the egg from deformation.

Animals↗

[The differentiation of Opisthorchis eggs by the ultrastructure of their outer membranes].

Using a TESLA-BS-300 scanning electron microscope, the ultrastructure of the outer membranes of oocysts of 8 opisthorchis species (Opisthorchis felineus, O. viverrini, O. geminus, Clonorchis sinesis, Amphimerus anatis, Metorchis albidus, Pseudamphistomum truncatum, Erchoviorchis lintoni) belonging to 4 subfamilies, as well as that of O. felineus oocysts of various geographical isolates (from the Ukraine, the Volga region, West Siberia, Kazakhstan) have been investigated. The nature of the ultrastructure of the membranes differs from species to species and can be used for the differentiation of opisthorchis oocysts. Marked differences have been observed in different opisthorchis subfamilies (Opisthorchinae, Metorchinae, Pseudamphistominae, Pseudamphimerinae). The membrane ultrastructure was not significantly different in O. felineus oocysts from various geographical isolates, however, there are some distinctions in the size of oocysts and the form of apical thorns and opercular endings. The work has been done within the framework of the international scientific cooperation between the E. I. Martsinovskiĭ Institute of Medical Parasitology and Tropical Medicine, USSR Ministry of Public Health and the Institute of Parasitology, the Czechoslovakian Academy of Sciences.

Animals↗

[Immunoblotting in the study of the antigenic structure of Leishmania].

Using immunoblotting, the antigenic structure of 6 Leishmania strains has been studied: 1) MHOM/IN/80/DDS--Leishmania (Leishmania) donovani; 2) MHOM/SU/63/VL--L. sp. ZMA; 3) MHOM/SU/73/K-27--L. tropica; 4) MHOM/SU/73/5Ash--L. major; 5) MHOM/GE/84/H-132--L. mexicana amazonensis; 6) REPT/SU/83/3960-GC--L. (Sauroleishmania) gymnodactyli. Antigens of Leishmania surface membranes and rabbit antisera against them have been used. Among the agents of leishmaniasis in the Old World (1-4), the most intensive antigenic lines were found in the medium and high-molecular mass area (43-200 kD). In L. (L) mexican a amazonensis (5) species-specific lines have been identified in 10-22 kD area, which is indicative of considerable antigenic differences in Leishmania of the Old and New Worlds. The most marked antigenic differences from other types were noted in L. (S) gymnodactyli (6). It was characterized by the absence of antigenic bands in the medium and high molecular mass areas, the lines associated with species-specific determinants located in the low molecular mass area (18 and 25 kD). The results of cross-reacting c-ELISA using the same antigens and antisera correlated well with the above data of immunoblotting. Immunoblotting may be used for identification of species-specific antigenic structures which may be helpful in serological tests for more accurate leishmania identification and leishmaniasis diagnosis.

Animals↗