Effects of praziquantel and oxamniquine on a Saudi Arabian strain of Schistosoma mansoni in mice

1990 ◽  
Vol 64 (1) ◽  
pp. 62-64 ◽  
Author(s):  
A. M. Ghandour ◽  
A. A. Banaja ◽  
I. M. Shalaby

ABSTRACTThe prophylactic and curative effects of praziquantel and oxamniquine on a Saudi Arabian strain of Schistosoma mansoni in MF-1 mice were assessed. The drugs were administered orally. At 240 mg/kg praziquantel, there was a reduction of 89·1% in adult worm recovery and a marked reduction in tissue deposited eggs. The reduction in adult worm recovery after dosing with 50 mg/kg oxamniquine was 89·2%. At low doses (40 mg/kg praziquantel and 30 mg/kg oxamniquine) administered at 11 days, 5 days and 3 h before and 5, 21 and 49 days after infection, the reduction in adult worm recovery was 0·0%, 65·1%, 58·8%, 33·6%, 0·0% and 76·0% for praziquantel and 0·0%, 66·0%, 60·0%, 41·3%, 10·8% and 79·0% for oxamniquine. Numbers of lung schistosomula and the size of hepatic granulomata were also reduced.

1976 ◽  
Vol 50 (3) ◽  
pp. 193-196 ◽  
Author(s):  
A. M. Ghandour

AbstractIt was shown that maintenance of cercariae of S. mansoni and S. haematobium at low (10°C) and high temperatures (40°C) markedly increased their mortality during penetration of mammalian host skin. These increased losses in the skin accounted for the known decrease in infectivity, as measured by adult worm recovery, of cercariae kept at low or high temperatures.


1982 ◽  
Vol 77 (2) ◽  
pp. 165-171
Author(s):  
Nelia S. Tan-Liu ◽  
Moyses Sadigursky ◽  
Zilton A. Andrade

Five rabbits infected with Schistosoma mansoni showed marked resistance, which resulted in low worm recovery and low egg production. Pathological changes appeared in liver and intestines as scattered foci of eosinophilic infiltration around immature eggs, with only occasional granulomatous formation. Antibodies to ovular and adult worm structures were demonstrated by immunofluorescence in the sera of rabbits prior to infection (natural antibodies) and specially following infection by S. mansoni. These findings point out to the peculiarities of the immunopathology of schistosomiasis in rabbits.


Parasitology ◽  
1984 ◽  
Vol 88 (3) ◽  
pp. 505-514 ◽  
Author(s):  
R. F. Sturrock ◽  
B. J. Cottrell ◽  
R. Kimani

SUMMARYUsing groups of 4 baboons (Papio anubis), 21·0% of a trickle exposure of 480Schistosoma mansonicercariae/baboon (10/week for 48 weeks) were recovered as adult worms (Group A) compared with 72·6% from a single massive exposure of 2500 cercariae/baboon (Group C). Group B, exposed first to the trickle and then to the massive exposure simultaneously with Groups A and C, yielded a worm recovery of 54% which was slightly but significantly less than Group C. The trickle infection apparently induced a substantial resistance to light re-exposure, but only a partial, although significant, resistance to a massive re-exposure. In Group B, however, there was a marked reduction in the degree of gross pathology, despite high tissue egg production by the mature challenge worms. The parasitological results, in terms of resistance to reinfection by and development of pathology to a trickle infection, are not materially different from those obtained in studies using conventional heavy primary and challenge exposures withS. mansoni. The significance of these findings is discussed in relation to the epidemiology of human schistosomiasis mansoni in which heavy exposures are believed to be the exception rather than the rule.


1990 ◽  
Vol 32 (3) ◽  
pp. 168-171 ◽  
Author(s):  
Marco Victor Hermeto ◽  
Rosilene Siray Bicalho ◽  
Alan Lane de Melo ◽  
Leógenes Horácio Pereira

In the experimental schistosomiasis mansoni glucocorticoids cause a reduction in the worm burden when administered in the week of infection or, the longest, at the next week. In order to determinate the probable(s) site(s) of reduction of the worm burden, mice were infected with cercariae of LE strain of S. mansoni and dexamethasone was administered daily (50 mg/kg, subcutaneously) starting 1 hour before infection until the eighth day. Mice were sacrificed daily starting on the third day after infection until the ninth day, and schistosomula from lungs were collected. Six weeks after infection, the remaining mice were sacrificed and perfused for adult worm recovery. Analysis of the results showed that the non-treated mice presented larger numbers of lung larvae than the treated ones, and this difference was also found later in the worm burden in the portal system. This difference may reflect the early death of larvae in treated animals, before or after reaching the lungs.


1975 ◽  
Vol 49 (4) ◽  
pp. 245-250 ◽  
Author(s):  
A. M. Ghandour

ABSTRACTExperiments were conducted to assess the effect of sublethal concentrations of niclosamide on the infectivity ofSchistosoma mansonicercariae. Exposure of cercariae to 0.02 mg/1 and 0.05 mg/1 of niclosamide, respectively, for only two hours increased their mortality during penetration of mammalian host skin. The observed increase in mortality in the skin resulted in a consequent reduction of adult worm recovery from the liver and mesenteric veins of animals infected with the treated cercariae.


1977 ◽  
Vol 51 (1) ◽  
pp. 71-72 ◽  
Author(s):  
Mauro Scapin ◽  
Miriam Tendler

Several methods are being applied for solubilizing adult Schistosoma mansoni antigens which may allow their immunochemical characterization and purification. Studies on antigens and immunoprecipitins in schistosome infections have been carried out with homogenized extracts of adult worms and/or larval forms of Schistosoma mansoni in saline (Biguet et al., 1962; Kagan and Norman, 1963; Silva and Ferri, 1965), or water (Kent, 1963). Kusel (1972) studied surface proteins in S. mansoni membrane, treating the worms with 0·5% saponin in 3% calcium chloride. Murrel et al. (1974) compared by immunodiffusion a crude culture antigen with extracts obtained by freeze-thawing of adult worms and by treatment in 3M KCl.


Parasitology ◽  
1996 ◽  
Vol 113 (4) ◽  
pp. 367-375 ◽  
Author(s):  
M. V. Johansen ◽  
Y. Fillié ◽  
J. Monrad ◽  
N. Ø. Christensen ◽  
A. Deelder

SUMMARYCirculating antigen levels and antibody responses in Schistosoma bovis-infected West African Dwarf goats were evaluated during infection and following treatment with praziquantel (60 mg/kg) 13 weeks post-infection. One day, 1 week and 4 weeks post-treatment, subgroups of goats were sacrificed and perfused for worm recovery. For comparison, parasite-free control animals were included. Blood and faecal samples were collected biweekly. Two gut-associated schistosome antigens, circulating cathodic and circulating anodic antigen (CCA and CAA) and 3 specific antibody responses (total Ig, IgG and IgM) were measured. For specific antibody detection, crude S. bovis adult worm and egg homogenates were used. The level of CCA in the infected groups was significantly elevated from the time of onset of egg excretion onwards. However, following treatment, the CCA litres dropped to control levels within 1 week post-treatment. Strong positive correlations were found between CCA levels and worm counts and faecal egg counts during peak egg excretion. The correlations of CAA and specific antibody litres to egg and worm counts were poor. The antibody responses were all significantly elevated in the infected goats during patency, but only marginally affected by the treatment. Hence, CCA proved to be superior by correlating strongly to the level of infection and by being a sensitive indicator of the effect of treatment.


2009 ◽  
Vol 83 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Y. Mitsui ◽  
M. Miura ◽  
Y. Aoki

AbstractThe effect of artesunate (ART) on the survival time of adult worm pairs of Schistosoma mansoni and on their egg output during in vitro culture was assessed. ART significantly decreased the survival time of both paired male and female worms at concentrations of 5, 10, 20 and 40 mg l− 1 during in vitro cultivation. An inhibitory effect of ART on the daily egg output of paired female worms during in vitro cultivation was also observed.


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