scholarly journals Loss of covalently labeled glycoproteins and glycolipids from the surface of newly transformed schistosomula of Schistosoma mansoni.

1982 ◽  
Vol 94 (2) ◽  
pp. 363-369 ◽  
Author(s):  
J C Samuelson ◽  
J P Caulfield
Keyword(s):  
Schistosoma Mansoni ◽  
Trichloroacetic Acid ◽  
Culture Medium ◽  
Surface Membrane ◽  
Apparent Molecular Weight ◽  
Acid Precipitation ◽  
Defined Medium ◽  
Galactose Oxidase ◽  
Newly Transformed Schistosomula

Schistosomula of Schistosoma mansoni were labeled by oxidation with galactose oxidase or with periodate followed by reduction with NaB3H4 to study the loss of the surface membrane of these parasites in vitro. Grain counts of light microscope autoradiographs (LMARG) of radiolabeled schistosomula show that both galactose oxidase and periodate specifically label the surface of the organisms. Galactose oxidase labels 11 glycoproteins on the surface of skin and mechanical schistosomula, ranging in apparent molecular weight from 17,000 to greater than 105,000. These glycoproteins are lost from the surface of schistosomula with a halftime of 10-15 h in culture in defined medium. Most of these glycoproteins appear to be shed intact from the surface of the schistosomula rather than endocytosed and degraded, because greater than 50% of each of the lost proteins can be recovered by trichloroacetic acid precipitation of the culture medium and because there is no internalization of the radiolabels into cultured schistosomula examined by LMARG. In addition to glycoproteins, periodate labels at least seven glycolipids on the surface of mechanical schistosomula. After culture for 15 h, more than half of each of these periodate-labeled proteins and lipids are lost from the schistosomula, and their abundance relative to each other remains similar to that of freshly labeled organisms. Since both proteins and lipids are lost from the surface of the schistosomula at the same rate, we believe that we are observing a general loss of the parasite surface membrane.

scholarly journals Transcriptional Profiling of Porcine Blastocysts Produced In Vitro in a Chemically Defined Culture Medium

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1414
Author(s):  
Josep M. Cambra ◽  
Emilio A. Martinez ◽  
Heriberto Rodriguez-Martinez ◽  
Maria A. Gil ◽  
Cristina Cuello
Keyword(s):  
Culture Medium ◽  
Embryo Quality ◽  
Transcriptional Profiling ◽  
Defined Medium ◽  
Platelet Factor ◽  
Defined Media ◽  
Defined Culture ◽  
The Impact

The development of chemically defined media is a growing trend in in vitro embryo production (IVP). Recently, traditional undefined culture medium with bovine serum albumin (BSA) has been successfully replaced by a chemically defined medium using substances with embryotrophic properties such as platelet factor 4 (PF4). Although the use of this medium sustains IVP, the impact of defined media on the embryonic transcriptome has not been fully elucidated. This study analyzed the transcriptome of porcine IVP blastocysts, cultured in defined (PF4 group) and undefined media (BSA group) by microarrays. In vivo-derived blastocysts (IVV group) were used as a standard of maximum embryo quality. The results showed no differentially expressed genes (DEG) between the PF4 and BSA groups. However, a total of 2780 and 2577 DEGs were detected when comparing the PF4 or the BSA group with the IVV group, respectively. Most of these genes were common in both in vitro groups (2132) and present in some enriched pathways, such as cell cycle, lysosome and/or metabolic pathways. These results show that IVP conditions strongly affect embryo transcriptome and that the defined culture medium with PF4 is a guaranteed replacement for traditional culture with BSA.

Schistosoma mansoni: a comparative study of artificially transformed schistosomula and schistomula recoverd after cercarial penetration of isolated skin

Parasitology ◽  
1977 ◽  
Vol 74 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Linda H. Brink ◽  
Diane J. McLaren ◽  
S. R. Smithers
Keyword(s):  
Comparative Study ◽  
Schistosoma Mansoni ◽  
Amorphous Material ◽  
Surface Membrane ◽  
Antigenic Determinants ◽  
Agglutination Reaction ◽  
Rat Serum ◽  
Mechanical Separation ◽  
B Blood Group

A comparison was made of the ultrastructure, development and antigenic nature of the surfaces and of the viability of three types of schistosomula of Schistosoma mansoni: schistosomula formed afrer cercariae had penetrated isolated skin (SS), schistosomula produced after mechanical separation of cercarial tails from bodies (MS), and schistosomula transformed from cercariae after incubation in fresh rat serum (RS).Within 2 h of transformation, the surface membrane of all three types of schistosomula had changed from trilaminate to heptalaminate structures and SS and MS had lost their cercarial glycocalyx. Initially a dense amorphous material was demonstrated on the surfaces of RS, which was thought to be the result of an interaction between a factor in rat serum and the glycocalyx: this material was greatly reduced within 2 h of transformation. The pre-acetabular glands of SS were emptied while those of MS and RS retained their contents. Immunofluorescent studies showed that all schistosomula bound serum from mice immune to S. mansoni, but the binding was stronger with MS and RS. The mixed agglutination reaction demonstrated the presence of human A and B blood group-like antigenic determinants on approximately 30% of 3 h old SS; these determinants were not detected on MS or RS. In vitro, the development of MS and RS was similar to SS; the first schistosomula reached the ‘gut-closed’ stage by day 10; 50–70% of SS reached this stage by day 12, in contrast to only 25–50% of MS and RS. Between 28 and 45% of all schistosomula developed to maturity when injected intravenously into mice.It was concluded that the two types of artificially prepared schistosomula fultil the main criteria of transformation from cercaria to schistosomulum. Further, it is suggested that MS are the most appropriate source of material for immunochemical and physiological studies.

scholarly journals Oviposition by Schistosoma mansoni during in vitro cultivation

1996 ◽  
Vol 38 (6) ◽  
pp. 423-426 ◽  
Author(s):  
Leo Roberto Barth ◽  
Ana Paula Morais Fernandes ◽  
Vanderlei Rodrigues
Keyword(s):  
Schistosoma Mansoni ◽  
Egg Production ◽  
Culture Medium ◽  
Parasite Development ◽  
In Vitro Cultivation ◽  
Progressive Reduction ◽  
Maximum Period ◽  
Medium Time ◽  
Kinetics Of

Observation of Schistosoma mansoni oviposition during in vitro culture of adult worms for a maximum period of 10 days showed three well distinct phases in the kinetics of oviposition: an initial phase with low egg production, a period of maximum oviposition and finally a progressive reduction in the number of eggs during the late phases of culture. The kinetics of oviposition and the number of eggs laid by the parasites are influenced by the number of worm pairs per amount of RPMI 1640 medium, time of parasite development in the vertebrate host and type of serum utilized in the culture medium.

Schistosoma mansoni: evidence for a role of serum factors in protecting artificially transformed schistosomula against antibody-mediated killing in vitro

Parasitology ◽  
1978 ◽  
Vol 77 (2) ◽  
pp. 225-233 ◽  
Author(s):  
C. A. P. Tavares ◽  
Rita C. Soares ◽  
P. M. Z. Coelho ◽  
G. Gazzinelli
Keyword(s):  
Schistosoma Mansoni ◽  
Protective Factor ◽  
Gel Filtration ◽  
Defined Medium ◽  
Rabbit Serum ◽  
Chemically Defined Medium ◽  
Lethal Effects ◽  
Serum Factors

SummaryArtificially transformed schistosomula of Schistosoma mansoni develop a consistent but small protection against the lethal effects of antibody plus complement when cultured for 24 h in a chemically defined medium. In contrast, they become rapidly resistant to antibody plus complement, when cultured in the presence of a complex medium consisting of equal parts of heat-inactivated rabbit serum and Earle's/lactalbumin or in defined medium supplemented with small amounts of heat-inactivated rabbit serum. Sephadex G-200 gel filtration revealed that the protective factor in rabbit serum is a macromolecule with a molecular weight between 7 and 19S. Parasites cultured at 10 °C or in the presence of 200 μg of puromycin show less serum-induced protection against the lethal effects of antibody plus complement than do controls.

Fluorescent lipid uptake and transport in adult Schistosoma mansoni

Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 81-89 ◽  
Author(s):  
D. Moffat ◽  
J. R. Kusel
Keyword(s):  
Schistosoma Mansoni ◽  
External Medium ◽  
Surface Membrane ◽  
Lipid Uptake ◽  
Lipophilic Compounds ◽  
Oesophageal Gland ◽  
Labelled Compound ◽  
Positively Charged ◽  
Uptake And Transport

Fluorescent lipophilic compounds can be used to label the surface membrane of Schistosoma mansoni by adding the compound in small amounts of organic solvents to aqueous medium in vitro. Under these conditions it is difficult to follow routes of distribution of the label. Here we have absorbed nitrobenzoxadiazolamine methylamino–(NBD)–ceramides to positively charged Dowex beads, and incubated the labelled beads with living parasites. The NBD–ceramide transfers to the surface membrane as a patch 50–100 μm in diameter, after which the label can be seen localized in the gut and in a very concentrated form in organelles within the oesophageal gland cells. Subsequently the labelled compound can be found in organelles within other body cells, including subtegumental cells. We show that the labelled ceramide has been transported from the patch in the surface membrane through internal membrane systems to the destination in the gut and oesophageal gland and not transported through the gut via the external medium. A different pattern was observed when NBD–cholesterol was used. The pharynx was rapidly labelled when NBD–cholesterol was added in medium with or without serum or attached to red blood cells only. Diffuse labelling of the surface membrane and oesophageal gland occurred. We have demonstrated a novel route of lipid transport within the parasite. The route requires the surface membrane to have very specialized regions to facilitate such transport.

scholarly journals Schistosomula of Schistosoma mansoni clear concanavalin A from their surface by sloughing.

1982 ◽  
Vol 94 (2) ◽  
pp. 355-362 ◽  
Author(s):  
J C Samuelson ◽  
J P Caulfield ◽  
J R David
Keyword(s):  
Schistosoma Mansoni ◽  
Concanavalin A ◽  
Binding Sites ◽  
Culture Medium ◽  
Culture Media ◽  
Lectin Binding ◽  
Defined Medium ◽  
Con A ◽  
Sds Page ◽  
Lectin Binding Sites

The lectin concanavalin A (Con A) was used as a model probe to study the behavior of molecules bound to the surface of recently transformed schistosomula of Schistosoma mansoni. Con A binding was saturable (150-180 pg/organism) and specifically competed by alpha-methyl mannoside. Both FITC-Con A and 125-I-Con A were lost from the surface of schistosomula with a halftime of 8-10 h in culture in defined medium. A comparable decrease in the binding of Con A to schistosomula cultured and then labeled with the lectin indicated that the labeling procedure itself was not inducing the observed change. Internalization of Con A was not seen by either fluorescence microscopy or electron microscope radioautography. In addition, 70-80% of the radioactivity lost from the parasite was recoverable by TCA precipitation from the culture medium as intact Con A (27,000 mol wt on SDS PAGE). Thus, the mechanism of clearance of bound Con A from the surface of cultured schistosomula is apparently by sloughing of Con A molecules intact into the culture media and not by endocytosis and degradation. Con A binding sites, visualized with hemocyanin by scanning electron microscopy, appeared homogeneously distributed over the surface of schistosomula when organisms were labeled at 4 degree C or after fixation with glutaraldehyde. However, Con A and hemocyanin formed aggregates on the surface of schistosomula when labeling was performed at 37 degrees C, which suggests that lectin binding sites have lateral mobility within the plane of the membrane. These aggregates are likely independent of metabolism by the parasite because aggregation also occurs on the surface of organisms killed with azide.

scholarly journals In vitro production of cattle blastocysts in chemically defined medium with or without insulin supplementation

1996 ◽  
Vol 5 (5) ◽  
pp. 509-514 ◽  
Author(s):  
Kristiina Bredbacka ◽  
Peter Bredbacka
Keyword(s):  
Bovine Serum Albumin ◽  
Culture Medium ◽  
Defined Medium ◽  
Blastocyst Stage ◽  
Chemically Defined Medium ◽  
In Vitro Production ◽  
Cell Numbers ◽  
Vitro Production ◽  
Bovine Oocytes

In this study we evaluated the use of a chemically defined medium in the production of blastocysts from bovine oocytes fertilized in vitro. As culture medium we used CRI-PVP, a modification of CRlaa medium with bovine serum albumin replaced by polyvinylpyrrolidone. After 168 h of culture (192 h after insemination) 8.7%, 10.5 and 12.8% of the cleaved embryos developed to the blastocyst stage in the presence of 0, 2 or 200 nM insulin, respectively. The supplementation of 200 nM insulin tended to increase cell numbers in morulae and blastocysts (P=0.10). It is concluded that CRI-PVP can be used as a chemically defined medium in the production of blastocysts from bovine 1-cell embryos. However, further modifications are needed, and the insulin concentrations used may be below the optimum for blastocyst production.

scholarly journals In vitro Antischistosomal Activity of Clerodendrum umbellatum Poir (Labiateae) Leaves Aqueous Extract and Derived Fractions against Schistosoma mansoni Adult Worms

2020 ◽  
pp. 40-49
Author(s):  
Mérimé Christian Kenfack ◽  
Hermine Boukeng Jatsa ◽  
Nestor Gipwe Feussom ◽  
Emilienne Tienga Nkondo ◽  
Ulrich Membe Femoe ◽  
...  
Keyword(s):  
Motor Activity ◽  
Schistosoma Mansoni ◽  
Aqueous Extract ◽  
Culture Medium ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Phytochemical Screening ◽  
Methanol Fraction ◽  
Antischistosomal Activity

Aims: Treatment against schistosomiasis relies on praziquantel. Its treatment failure and the possible development of resistant schistosomes strains have been reported in the literature. Clerodendrum umbellatum leaves are used in Africa for the treatment of intestinal helminthiasis. The aim of this study was to evaluate the in vitro activity of C. umbellatum leaves aqueous extract and derived fractions on Schistosoma mansoni adult worms. Methodology: Five male and five female Schistosoma mansoni adult worms were incubated in each well for 48 h in a GMEM culture medium with C. umbellatum aqueous extract (125 to 4000 µg/mL) or its n-hexane, ethyl acetate and methanol fractions or the aqueous residue (62.5 to 2000 µg/mL). The main parameters assessed were the worm’s mortality and the reduction of motor activity. Phytochemical screening of all our tested substances was also performed. The cytotoxicity assay using mouse melanoma liver cells line was performed on the aqueous extract and on the most active fraction. Results: Our study shown that C. umbellatum leaves aqueous extract and its derived fractions promoted worm mortality. The aqueous extract disclosed a LC50 of 805.21 µg/mL while the LC50 of the methanol fraction was 343.10 µg/mL. With this lowest LC50, the methanol fraction from C. umbellatum aqueous extract was therefore the most active. Moreover, it showed low level of toxicity on hepatocytes. Incubation of worms with C. umbellatum aqueous extract and fractions also resulted in a significant reduction of the motor activity of survival worms with a 39.54 to 100% reduction after 48h. The phytochemical screening of C. umbellatum aqueous extract and fractions revealed the presence of alkaloids, phenols, flavonoids, tannins, saponins and terpenoids. Conclusion: The present study demonstrated the in vitro activity of C. umbellatum aqueous extract and derived fractions on S. mansoni adult worms and could then justify its empirical use to combat schistosomiasis.

Preliminary Experiments with a Defined Culture Medium for Larval Fasciola hepatica

1973 ◽  
Vol 47 (2) ◽  
pp. 181-189 ◽  
Author(s):  
R. S. V. Pullin
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Fasciola Hepatica ◽  
Dry Weight ◽  
Defined Medium ◽  
Inorganic Salts ◽  
Final Maturation ◽  
Defined Culture ◽  
Stock Solutions

A defined medium is described as a basis for in vitro culture work with larval Fasciola hepatica. This medium, termed BCM, can be quickly made up by using a system of stock solutions. BCM contains inorganic salts, glucose, amino acids, vitamins and antibiotics, but no lipid or proteins. Rediae can be dissected from infected snails for culture, but many appear to be contaminated with bacteria. Large rediae cannot survive in BCM but free immature cercariae can complete their final maturation in vitro. This final maturation, from the 30th to the 35th day after miracidial penetration of donor snails, includes tail growth and appearance of body pigmentation. Cercariae matured in vitro encyst successfully when transferred from BCM to water. Small rediae survive in BCM for 5 days, but show no growth or development measured as dry weight and total nitrogen.

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