Cercarial tail loss in Echinostoma caproni: the influence of in vivo encystment and copper sulphate

2005 ◽  
Vol 79 (2) ◽  
pp. 177-178 ◽  
Author(s):  
B. Fried ◽  
J.L. Schneck
Keyword(s):  
Copper Sulphate ◽  
Biomphalaria Glabrata ◽  
Spring Water ◽  
Echinostoma Caproni ◽  
Tail Loss ◽  
Water Ph

AbstractEchinostoma caproni tail loss was studied in vitro in the presence of the toxicant copper sulphate (CuSO4) in concentrations ranging from 1 to 10 000 mg l?1 in standardized artificial spring water (pH 7.4, osmolarity 34 mOsm kg?1 H2O, Ca2+ 20 mg l?1) at 23°C. Tail loss was also studied in the absence of toxicants during in vivo encystment of the cercariae in juvenile Biomphalaria glabrata. As the concentration of CuSO4 increased, the percentage of cercarial tail loss increased. By 2 h in 10 000 mg l?1, 1000 mg l?1 and 100 mg l?1 CuSO4, 50%, 23% and 13%, respectively, of the cercariae had lost their tails. In the in vivo studies, by 1 h PI, 59±5% of cercariae had lost their tails and only 4±1% of the cercariae were actively swimming in the multi-well dishes. At 3 h PI, 72±3% of the cercariae began to form cysts within the snails.

Effects of copper sulphate on in vitro encystment of the cercariae of Echinostoma caproni

2004 ◽  
Vol 78 (4) ◽  
pp. 371-372 ◽  
Author(s):  
B. Fried ◽  
J.L. Schneck
Keyword(s):  
Emergency Response ◽  
Cyst Wall ◽  
Copper Sulphate ◽  
Bile Salts ◽  
Spring Water ◽  
Echinostoma Caproni ◽  
Parorchis Acanthus ◽  
High Concentrations

AbstractThe effects of various concentrations of copper sulphate were studied on in vitro encystment of Echinostoma caproni in a Locke's–artificial spring water (ASW) (1:1) medium. Cercariae were killed in 10,000 mg l−1 CuSO4 in Locke's–ASW (1:1) within 24 h and extruded cystogenous material to produce an abnormal cyst wall. The ‘emergency response’ of encystment to high concentrations of copper reported for Parorchis acanthus cercariae did not occur in E. caproni. Concentrations of 1000 mg l−1 and 100 mg l−1 CuSO4 in Locke's–ASW (1:1) also killed the cercariae without encystment by 48 h. A concentration of 10 mg l−1 CuSO4 in Locke's–ASW (1:1) allowed for normal in vitro encystment within 48 h and these cysts were capable of excystation in a trypsin–bile salts medium.

scholarly journals Trematocidal Activity of Praziquantel and Artemisinin Derivatives: In Vitro and In Vivo Investigations with Adult Echinostoma caproni

2006 ◽  
Vol 50 (2) ◽  
pp. 803-805 ◽  
Author(s):  
Jennifer Keiser ◽  
Reto Brun ◽  
Bernard Fried ◽  
Jürg Utzinger
Keyword(s):  
Body Weight ◽  
Worm Burden ◽  
Echinostoma Caproni ◽  
Artemisinin Derivatives ◽  
Exposure Response ◽  
Oral Doses

ABSTRACT We examined the effects of praziquantel and the artemisinins on adult Echinostoma caproni. In vitro, both praziquantel and the artemisinins exhibited exposure-response relationships. In vivo, worm burden reductions of 100% were achieved with single oral doses of praziquantel, artesunate, and artemether at 50, 700, and 1,100 mg/kg of body weight, respectively.

Effects of temperature on survival, infectivity and in vitro encystment of the cercariae of Echinostoma caproni

2003 ◽  
Vol 77 (3) ◽  
pp. 235-238 ◽  
Author(s):  
B. Fried ◽  
E.L. Ponder
Keyword(s):  
Spring Water ◽  
Helisoma Trivolvis ◽  
Echinostoma Caproni ◽  
Maximal Life Span ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Effects Of Aging ◽  
C 78 ◽  
Infective Period

AbstractThe effects of temperature on survival, infectivity and in vitro encystment of Echinostoma caproni cercariae in artificial spring water (ASW) were studied. Effects of aging cercariae in ASW at various temperatures showed that at 23°C cercariae achieved 50% survival in 24 h, compared to 92 h at 12°C. Cercariae aged in ASW at 28 and 37.5°C showed 50% survival at 16 and 10 h, respectively. Cercariae aged at different temperatures for various times were used to infect juvenile Helisoma trivolvis (Colorado strain) snails maintained in ASW at 23°C. Index of infectivity was based on counting encysted metacercariae in the snails at 8 to 12 h post-infection. Cercariae aged at 23, 28 and 37.5°C showed 50% encystment at 6, 8 and 4 h, respectively. Cercariae aged at 4°C showed 50% encystment in 10 h and cercariae aged at 12°C showed 50% encystment beyond 16 h. Cercariae showed maximal longevity and infectivity in snails when aged at 12°C in ASW. For E. caproni, as in other digeneans, the infective period of cercariae is markedly shorter than the maximal life-span at any given temperature. Studies on in vitro encystment of E. caproni cercariae in Locke's solution:ASW (1:1) showed that encystment was optimal at 23°C (78% encystment) and that it declined to 44% at 28°C and became almost nil (0.02%) at 12 or 37.5°C.

In vitro and In vivo Encystment of the Cercariae of Echinostoma caproni

2002 ◽  
Vol 88 (6) ◽  
pp. 1124 ◽  
Author(s):  
Bernard Fried ◽  
Robert LaTerra
Keyword(s):  
Echinostoma Caproni

Emergence of cercariae of Echinostoma caproni and Schistosoma mansoni from Biomphalaria glabrata under different laboratory conditions

2002 ◽  
Vol 76 (4) ◽  
pp. 369-371 ◽  
Author(s):  
B. Fried ◽  
R. Laterra ◽  
Y. Kim
Keyword(s):  
Schistosoma Mansoni ◽  
Feeding Behaviour ◽  
Biomphalaria Glabrata ◽  
Spring Water ◽  
Echinostoma Caproni ◽  
Laboratory Conditions

AbstractRelease of Echinostoma caproni cercariae and Schistosoma mansoni from experimentally infected Biomphalaria glabrata snails maintained under different laboratory conditions was studied. Infected snails were isolated individually for 1 h in Stender dishes containing 5 ml of artificial spring water and the number of cercariae released during this time was recorded. Of numerous conditions tested, the addition of lettuce, the use of water conditioned by B. glabrata snails and a temperature of 35°C significantly increased the release of E. caproni cercariae. A significant increase in cercarial release of S. mansoni was seen only in cultures fed lettuce. A temperature of 12°C caused a significant decrease in cercarial release of both E. caproni and S. mansoni. Increased snail activity associated with feeding behaviour was probably responsible for the enhanced cercarial sheds observed in this study.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

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