Activity of the acetabular secretory apparatus of cercariae of Schistosoma mansoni under experimental conditions

1961 ◽  
Vol 11 (2-3) ◽  
pp. 191-211 ◽  
Author(s):  
M.A. Stirewalt ◽  
F.J. Kruidenier
Keyword(s):  
Schistosoma Mansoni ◽  
Experimental Conditions ◽  
Secretory Apparatus

Delayed tail loss during the invasion of mouse skin by cercariae of Schistosoma japonicum

Parasitology ◽  
2011 ◽  
Vol 139 (2) ◽  
pp. 244-247 ◽  
Author(s):  
TING WANG ◽  
ZHENG-MING FANG ◽  
JIA-HUI LEI ◽  
FEI GUAN ◽  
WEN-QI LIU ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Schistosoma Japonicum ◽  
Human Skin ◽  
Mouse Skin ◽  
Density Range ◽  
Experimental Conditions ◽  
Density Dependent ◽  
Tail Loss ◽  
Traditional Assumption

SUMMARYA traditional assumption is that schistosome cercariae lose their tails at the onset of penetration. It has, however, recently been demonstrated that, for Schistosoma mansoni, cercarial tails were not invariably being shed as penetration took place and a high proportion of tails entered human skin under experimental conditions. This phenomenon was termed delayed tail loss (DTL). In this paper, we report that DTL also happens with S. japonicum cercariae during penetration of mouse skin. It occurred at all cercarial densities tested, from as few as 10 cercariae/2·25 cm2 of mouse skin up to 200 cercariae. Furthermore, it was demonstrated that there was a density-dependent increase in DTL as cercarial densities increased. No such density-dependent enhancement was shown for percentage attachment over the same cercarial density range.

Schistosoma mansoni: tail loss in relation to permeability changes during cercaria–schistosomulum transformation

Parasitology ◽  
1975 ◽  
Vol 71 (1) ◽  
pp. 9-18 ◽  
Author(s):  
R. E. Howells ◽  
S. E. Gerken ◽  
F. J. Pinto-Ramalho ◽  
U. Kawazoe ◽  
G. Gazzinelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Methylene Blue ◽  
Schistosoma Mansoni ◽  
Body Region ◽  
Experimental Conditions ◽  
General Body ◽  
Tail Loss ◽  
Permeability Changes ◽  
Extensive Lesion ◽  
Scanning Electron

The hind-body region of Schistosoma mansoni cercariae observed in the scanning electron microscope demonstrates various stages of contraction which may be compared with those of living larvae which are secreting the acetabular gland contents.No evidence for an extensive lesion was found in cercarial bodies which had shed their tails under experimental conditions. Experiments on the permeability of the larvae to sodium fluoride, methylene blue and amino acids demonstrated that tail loss significantly affects the permeability of the bodies although the effect is greater immediately after decaudation than at later times. Subsequent increases in permeability may be correlated with a change in the general body surface.

scholarly journals Detection of circulating polysaccharide antigen of Schistosoma mansoni in hamster sera by crossed immunoelectrophoresis

1988 ◽  
Vol 30 (2) ◽  
pp. 72-78
Author(s):  
Margareth Fernandes ◽  
Ione Irulegui ◽  
Dirce Mary Correia Lima ◽  
Clarice Pires Abrantes ◽  
Martha Smith Cressoni ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Chronic Phase ◽  
Parasite Load ◽  
Polysaccharide Antigen ◽  
Experimental Conditions ◽  
Crossed Immunoelectrophoresis ◽  
Human Sera

Crossed immunoelectrophoresis (IEC) was used for detection of free and complexed circulating polisaccharide anodic antigen (AgCA) of Schistosoma mansoni in sera of infected hamsters. An attempt was also done to detect AgCA in human sera from patients infected with S. mansoni. The conditions for isolation and detection of complexed AgCA were established. The sensitivity of IEC was increased by incorporation of 2% polyethylene glicol (PEG) to the agarose and by maintaining the system at 4°C during the electrophoretic run. Free AgCA was detected in 12 and the complexed in 30 of the 37 hamsters sera analysed. Correlation between AgCA (free and complexed) and the parasite load was observed. AgCA was not detected, under the experimental conditions used, in human sera from 7 patients in the acute and 23 in the chronic phase of infection.

Tissue expression of the Schistosoma mansoni 28 kDa glutathione S-transferase

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 565-572 ◽  
Author(s):  
E. Porchet ◽  
A. McNair ◽  
A. Caron ◽  
J. P. Kusnierz ◽  
K. Zemzoumi ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Developmental Stages ◽  
Tissue Expression ◽  
Cross Reactivity ◽  
Glutathione S Transferase ◽  
Experimental Conditions ◽  
Neural Mass ◽  
Immunocytochemical Techniques ◽  
Hepatic Granulomas ◽  
Parenchymal Cells

The expression of the Schistosoma mansoni 28 kDa glutathione S-transferase (Sm28) was studied using molecular (PCR, in situ hybridization), and immunocytochemical techniques. The presence of Sm28 was demonstrated in all developmental stages of the parasite except the intra-uterine immature egg. In the parenchyma of male and female adult worms the distribution of Sm28 was limited to a subpopulation of parenchymal cells and to the dorsal tubercles of the male. The tegument, the muscles, the digestive tract, the neural mass, the vitelline glands, and mature gametes were not immunoreactive. Immature germinal cells in both sexes, and the ootype in the female genital system, were found to express Sm28. Deposits of immunoreactive material on host skin following cercarial penetration, exfoliation from the male tubercles, and especially emission of Sm28 from eggs in hepatic granulomas are suspected to be a source of antigen during the parasite infection. The reduction in worm fecundity previously observed in immunization experiments may result from an antibody response directed against Sm28 present in the ootype. There was no cross-reactivity observed, under the experimental conditions used, between the anti-Sm28 sera and either vertebrate or invertebrate host tissue.

scholarly journals Transmission of Schistosoma mansoni under experimental conditions using the bovine - Biomphalaria glabrata - bovine model

1993 ◽  
Vol 35 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Celina M. Modena ◽  
Paulo Marcos Z. Coelho ◽  
Frederico S. Barbosa ◽  
Walter S. Lima
Keyword(s):  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Endemic Area ◽  
Experimental Period ◽  
Biomphalaria Glabrata ◽  
Snail Population ◽  
Experimental Conditions ◽  
Worm Recovery ◽  
The Mean

Three calves experimentally infected with Schistosoma mansoni, and passing viable eggs in feces, as well as 5 normal calves (coming from a non-endemic area for schistosomiasis) kept as controls, were maintained in an enclosure (850 m² in area). In this enclosure, a tank with water received 500 laboratory reared Biomphalaria glabrata. All the control calves were infected for a period ranging from 79 to 202 days after the beginning of the experiment, and afterwards presented viable S. mansoni eggs in feces. The mean worm recovery was 555. The snail population increased throughout the experimental period, showing a high number of B. glabrata infected with S. mansoni (42% on average). According to the present study, bovine has been suggested as having potentially a role in the maintenance of the life cycle of S. mansoni

scholarly journals Susceptibility of Biomphalaria tenagophila and Biomphalaria glabrata from the same region to two Brazilian strains of Schistosoma mansoni

1994 ◽  
Vol 36 (5) ◽  
pp. 409-415 ◽  
Author(s):  
Roney Elias da Silva ◽  
Alan Lane de Melo ◽  
Leógenes Horácio Pereira
Keyword(s):  
Schistosoma Mansoni ◽  
Infection Rate ◽  
Biomphalaria Glabrata ◽  
Infection Rates ◽  
Experimental Conditions ◽  
Belo Horizonte ◽  
Cabo Frio

B. tenagophila snails from Ouro Branco, MG, showed positivity for S. mansoni, with infection rates of 5%, 10%, (SJ strain), and 1% (LE strain) using a pool of miracidia. The mollusks were found to be susceptive from the 3rd generation reared in laboratory onwards. The B. tenagophila (OB, MG) when individually exposed to 10 miracidia, showed infection rate of 2% for LE strain. B. glabrata snails from Gagé, MG, showed a positivity rate of 58% for S. mansoni (LE strain), under experimental conditions. The B. tenagophila from Cabo Frio, RJ and B. glabrata from Belo Horizonte, MG used as a control for SJ strain showed infection rates of 47% - 85% and 36% respectivily. For the LE strain, B. glabrata (BH, MG) used as control showed infection rate of 40% - 75%.

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

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