Scanning and Transmission Electronmicroscopy of Schistosoma Mansoni Eggs, Cercariae, and Adults *

Race, George J.; Martin, J. Holmes; Moore, Donald V.; Larsh, John E.

doi:10.4269/ajtmh.1971.20.914

Cited by 46 publications

(19 citation statements)

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“…1). These features are in agreement with previously reported descriptions (Silk et al 1970, Race et al 1971, Miller et al 1972. Conversely, the function of the ventral sucker is more related to the displacement of the specimen, considering that this structure is bigger than the oral sucker and with sensorial papillae that are mechano-receptor structures (Hockley 1973).…”

Section: Discussionsupporting

confidence: 92%

“…Through the scanning electron microscopy (SEM), the descriptive analysis of Schistosoma mansoni Sambon, 1907 adult worms was achieved. Thus, it was demonstrated that small spines cover the inner surface of the oral and ventral suckers, while the outer surface lacks these structures (Silk et al 1969, Race et al 1971. The inner surface of the ventral sucker presents sensorial papillae and a marginal ring of bigger spines (Hockley 1973).…”

Section: Tubercles Spines and Sensory Receptors Are The Most Studiedmentioning

confidence: 99%

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Morphological Study of Adult Male Worms of Schistosoma mansoni Sambon, 1907 by Scanning Electron Microscopy

Machado-Silva

Lanfredi

Gomes

1997

Mem. Inst. Oswaldo Cruz

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Section: Discussionsupporting

confidence: 92%

Section: Tubercles Spines and Sensory Receptors Are The Most Studiedmentioning

confidence: 99%

Morphological Study of Adult Male Worms of Schistosoma mansoni Sambon, 1907 by Scanning Electron Microscopy

Machado-Silva

Lanfredi

Gomes

1997

Mem. Inst. Oswaldo Cruz

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“…mansoni eggs represent a formidable target for PMN and mononuclear cells. Unlike the lipid-rich outer membranes of unicellular microbes (10) or the syncytium-bound schistosomula (11), the surface of schistosome ova consists of a hard "tanned" proteinaceous shell with multiple pores and microspicules (12)(13)(14). Within the shell but not in direct physical contact with mammalian tissues is the live miracidium, which releases enzymes and antigens (15,16).…”

Section: Introductionmentioning

confidence: 99%

Role of granulocyte oxygen products in damage of Schistosoma mansoni eggs in vitro.

Kazura¹,

Brito

Rabbege

et al. 1985

J. Clin. Invest.

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The objectives of this study were to describe the ultrastructure of granulocyte-Schistosoma mansoni egg interaction and to determine the role of reduced oxygen products as effectors of cell-mediated damage to the parasite target. Granulocytes attached to the parasites and closely applied their plasma membranes to the microspicules of the egg shell 30 min after mixing in the presence of immune serum. By 4 h, the egg shell was fractured and granulocyte pseudopodia extended toward the underlying miracidium. Granulocyte attachment to eggs resulted in release of O-(030-0.52 nmol/min per 2 X 106 cells) and accumulation of H202 (0.14-0.15 nmol/min) in the presence of antibody or complement. Granulocytes reduced egg tricarboxylic-acid cycle activity and hatching by 283±0.9 and 35.2±2.8%, respectively (cell-egg ratio of 1,000: 1). Exogenous superoxide dismutase (10 M&g/ml) inhibited granulocyte toxicity for egg metabolic activity (3.0±2.1% reduction in acetate metabolism vs. 283±0.9% decrease in controls without superoxide dismutase, P < 0.0005) and hatching (12.5±1.8% reduction, P < 0.0005), whereas catalase and heparin had no effect. Inhibitors of myeloperoxidase (1 mM azide, cyanide, and methimazole) augmented granulocyte-mediated toxicity of egg tricarboxylic-acid cycle activity (44-58% reduction in activity vs. 31 and 35% reduction in controls), suggesting that H202 released from cells was degraded before reaching the target miracidium. Oxidants generated by acetaldehyde (2 mM)-xanthine oxidase (10 mU/ml) also decreased egg metabolic activity and hatching by 62.0±9.0 and 38.7±73%, respectively. Egg damage by the cell-free system was partially prevented by superoxide dismutase (26.5±4.2% reduction in egg tricarboxylic-acid cycle activity) and completely blocked by catalase (0% reduction in activity). These data suggest that granulocyte-mediated toxicity for S. mansoni eggs is dependent on release of 02 or related molecules. These oxygen products, unlike H202, may readily reach the target miracidium where they may be converted to H202 or other microbicidal effector molecules.

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“…It is believed that the migration through the tissues is facilitated by soluble secretions excreted by the eggs through the micropores present in egg shells 23,[29][30][31][32][33] . Schistosoma mansoni egg proteome has been characterized in many studies, because the pathogenic consequences of the interaction of egg molecules with host immune system as well as the processes that underlie egg passage through the tissues and subsequent release with the feces are still poorly understood.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the immunogenicity of Schistosoma mansoni egg surface

Candido

Pierre

Jones

et al. 2017

Rev. Soc. Bras. Med. Trop.

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Introduction: Immunogenicity of Schistosoma mansoni egg surface was examined to determine whether intact eggshells have lower antigenicity than ruptured eggs. Methods: Swiss Webster mice were inoculated with intact or ultrasonicated S. mansoni eggs isolated from infected human feces. Mice were separated into four groups of six animals each and immunizations were performed approximately every 20 days during a 60-day period. Groups 1-4 were administered with saline solution, sonicated eggs with Freund's adjuvant, sonicated eggs without Freund's adjuvant, and intact eggs, respectively. IgG humoral immune response was assessed by ELISA using Soluble Egg Antigen produced from eggs isolated from the livers of infected mice. Results: Sonicated eggs co-administered with adjuvant induced the highest humoral response at 58 days, which was 11.9-fold (95% CI 6.2-17.5) greater than the response induced by saline solution. Sonicated eggs without adjuvant induced a 4.3-fold stronger response (95% CI 2.4-6.2) than normal saline. Intact eggs induced humoral response that was nominally twice stronger (95% CI 0.8-3.2) than that induced by normal saline but the effect did not reach statistical significance. Conclusions: Soluble antigens are not abundant on the surface of S. mansoni eggs and/or are not secreted in sufficient quantities to induce a significant immune response to intact eggs. Assuming that isolation procedures had not damaged the eggs used for inoculation, our observations suggest that intact eggs either do not induce a significant immune response or, if they do, the mechanism involves insoluble antigens from the egg surface.

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Scanning and Transmission Electronmicroscopy of Schistosoma Mansoni Eggs, Cercariae, and Adults *

Cited by 46 publications

References 0 publications

Morphological Study of Adult Male Worms of Schistosoma mansoni Sambon, 1907 by Scanning Electron Microscopy

Morphological Study of Adult Male Worms of Schistosoma mansoni Sambon, 1907 by Scanning Electron Microscopy

Role of granulocyte oxygen products in damage of Schistosoma mansoni eggs in vitro.

Evaluation of the immunogenicity of Schistosoma mansoni egg surface

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