Congenital transmission of Schistosoma japonicum in pigs.
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Congenital transmission of Schistosoma japonicum in pigs was investigated by experimentally infecting sows at four weeks gestation (n = 3), 10 weeks gestation (n = 3), or a few weeks prior to insemination (n = 2). None of the piglets born to sows infected prior to insemination or in early pregnancy were found to be infected. However, all of the piglets (n = 26) born to sows infected at 10 weeks gestation were found to harbor schistosomes with S. japonicum eggs recovered from both their feces and livers. The findings show that congenital S. japonicum infection of pigs can occur if sows are infected during mid-to-late pregnancy and may have important implications not only for pigs but also for other mammalian hosts of schistosomes, including humans. (+info)
Evidence for an improvement in cognitive function following treatment of Schistosoma japonicum infection in Chinese primary schoolchildren.
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A double-blind, placebo-controlled, treatment trial was conducted in Sichuan, China to investigate the unique and combined effects on the cognitive function (working memory) of children after treating geohelminth infections with albendazole and treating Schistosoma japonicum infection with praziquantel. One hundred eighty-one children 5-16 years of age participated. At baseline, the praziquantel and placebo groups were similar in all background characteristics. Three months after praziquantel treatment, there was a significant reduction in the prevalence and intensity of S. japonicum infection. There were significant age group by praziquantel treatment interaction effects in three of the five cognitive tests, Fluency, Picture Search, and Free Recall, with effects being strongest in the youngest children (5-7 years old). Exploratory analysis within the youngest children showed a significant positive main effect of treatment on Fluency (P < 0.001), after controlling for sex, anthropometric, and parasitic and iron status. There was also a treatment by height-for-age interaction (P = 0.03) and a treatment by iron status interaction (P = 0.024) on Fluency. There was a treatment by S. japonicum intensity interaction (P < 0.001) on Free Recall, but the main effect of treatment on Picture Search was not significant (P = 0.058). Younger children and those who are physically the most vulnerable are likely to benefit the most from the treatment of S. japonicum infection in terms of improved performance on tests of working memory. (+info)
Preventive effect of artemether on schistosome infection.
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OBJECTIVE: To study the preventive effect of artemether (Art) in protecting the people from schistosome infection during flood fighting in schistosomiasis endemic area of Poyang Lake, Jiangxi Province. METHODS: From mid July to mid August in 1996, the water level in Poyang Lake rose due to torrential rains and 2 embankments, Zhedi and Jiangtongdi, which appeared in dangerous situation and were selected as the pilot spots. After those who went to fight against flood arrived at the pilots their sera were collected within 48 hours and were examined with indirect hemagglutination test (IHA), enzyme-linked immunosorbent assay (ELISA) and McAb-ELISA. Individuals with negative outcome in the 3 tests were then selected as the study subjects and were allocated randomly to the Art or the control group. The first dose of Art given to the individuals contacted with the infested water within 11-15 days was 6 mg/kg. If the individual continually contacted the infested water, the same dose of Art was given once every 15 days. After the individuals withdrew from the pilot, one more dose of Art was administered 7-15 days later. Placebo (starch) was given to individuals in the control group at the same period as in artemether group. Stool examinations were made in both groups 40-50 days after the last medication for evaluation of the preventive effect of artemether. Double blind method was used in the administration of both artemether and placebo. RESULTS: In Zhedi pilot, the individuals fought against flood for about 1 month. In Art group, 99 individuals receiving 3 doses of the drug completed the stool examination with egg-positive rate of 4% and no acute schistosomiasis was seen. In the control group, among 110 people who completed the observation, 44 were egg-positive with an infection rate of 40%, and 29 were identified as having acute schistosomiasis. In Jiangtondi, the studied individuals contacted the infested water for only about 4 hours. But in the control group 4 out of 102 individuals were egg-positive, while none of the 103 individuals in Art group receiving 2 doses of the drug showed schistosome infection. No apparent side effect was seen in the people treated with artemether. CONCLUSION: After oral Art was given to the people fighting against flood in schistosomiasis endemic area of Poyang Lake, it was shown that the oral Art has a promising effect on controlling acute schistosomiasis and reducing the infection rate. (+info)
Effect of artemether on glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, and pyruvate kinase of Schistosoma japonicum harbored in mice.
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AIM: To study the effect of artemether (Art) on glyceraldehyde-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK), and pyruvate kinase (PK) of S japanicum. METHODS: Mice infected with schistosome cercariae for 32-38 d were treated ig with Art 100-300 mg.kg-1 and killed 24-72 h after medication for collection of schistosomes. The activities of GAPDH, PGK, and PK of the worms were determined by measuring the formation of NADH or consumption of NAD. The lactate content of the worms was also measured. RESULTS: After the infected mice were treated ig with Art 300 mg.kg-1 for 24 h, the inhibition rates of GAPDH were 13% (Male) and 21% (Female), and 48 h later the inhibition rates of the enzyme were 6% (Male) and 28% (Female). When Art 300 mg.kg-1 was given to infected mice for 24 h and 48 h, the inhibition rates of PGK were 60% (Male) and 48% (Female) as well as 75% (Male) and 62% (Female), respectively. Similar results were seen in PK activity. At 72 h after treatment the reduction rate of lactate content in Female worm was 72%, while that of Male was 48%. CONCLUSION: In the glycolytic pathway of both Male and Female schistosomes, PGK and PK activities were inhibited by Art. The GAPDH activity of Female worms was also susceptible to Art, While that of Male worms showed only temporary inhibition after treatment with Art. The Art reduced lactate content more in Female than in Male worms. (+info)
Preventive effect of artemether in rabbits infected with Schistosoma japonicum cercariae.
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AIM: To study the effect of artemether (Art) for prevention of schistosomal infection. METHODS: Rabbits with single infection or reinfection with Schistosoma japonicum cercariae were treated intramuscularly (i.m.) or intragastrically (i.g.) with Art 5 -20 mg.kg-1 on d 7-15 after the first infection, followed by various regimens. RESULTS: When rabbits were injected i.m. Art 7.5 mg.kg-1 (i.e., one half of the effective dose given i.g. on d 7) followed by once every week for twice, the female worm reduction rate was only 42%. In infected rabbits treated i.g. with Art 10-20 mg.kg-1 given in the same administration schedule, the female worm reduction rates were > 91%. When Art 15 mg.kg-1 was given to rabbits on d 7-14 and the following dose of the drug was given at intervals of 7-14 d, the female worm reduction rates were > 94%. In rabbits reinfected with cercariae, the female reduction rate of Art given i.g. once a week for 3 times since d 8 after the first infection was 96% which was similar to that given once a week twice since d 14 after the first infection. CONCLUSION: Art should be given i.g. on d 7-15 after infection, followed by repeated dosing once every 7-15 d for a total of 3 doses. Art given i.g. daily for 2 consecutive days or given at 1-wk intervals since 7-15 d after infection also showed preventive effect. (+info)
Hepatosplenic morbidity in schistosomiasis japonica: evaluation with Doppler sonography.
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In Southeast Asia, schistosomiasis japonica is an important cause of hepatic fibrosis and gastrointestinal hemorrhage. Reliable methods to investigate portal hypertension (PHT) clinically and epidemiologically on community level are lacking. Doppler sonography is an established tool for investigating PHT in hospital settings. In Leyte, The Philippines, 137 individuals underwent color Doppler sonography, stool examination, and serology for hepatitis B and C, liver cell injury and cholestasis. A total of 85% of the study population had been infected with Schistosoma japonicum. Sonographically, periportal liver fibrosis was seen in 25% and reticular echogenicities (network pattern) in 44%. Portal blood flow was decreased or portosystemic collaterals were present in 10% (adults throughout) and correlated with periportal fibrosis, but not with network lesions. Chronic viral hepatitis was rare. Thus, hepatic lesions are frequent in adults but not in children in areas endemic for S. japonicum. Periportal liver fibrosis indicates a risk of PHT, and network pattern fibrosis apparently does not. Doppler sonography is suitable for research under tropical field conditions. (+info)
Chronic Japanese schistosomiasis and hepatocellular carcinoma: ten years of follow-up in Yamanashi Prefecture, Japan.
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In a preliminary study carried out in the study area we found that 19.1% (173/907) of patients with chronic liver disease and 51% (35/68) of hepatocellular carcinoma cases were infected with Japanese schistosomiasis. Analysis of data from 571 autopsies revealed a similarly high incidence of schistosomiasis among cases of hepatoma and other liver diseases. A prospective case-control study conducted over 10 years showed that hepatoma developed in 5.4% (26/484) of chronic schistosomiasis cases and in 7.5% (23/307) of patients with chronic liver disease (hepatitis, cirrhosis, etc). The difference was not statistically significant (P = 0.228). A high incidence of hepatitis C virus (HCV) antibody (HCVAb) was found in the schistosomiasis group (36.5%; 95% CI = 44.9-28.1%) and in the chronic liver disease group (56.0%), 39% of whom had chronic hepatitis (P = 0.028). Various factors that might have contributed to the development of hepatoma and schistosomiasis were investigated, but no evidence of a significant correlation between schistosomiasis and hepatoma was found. The high incidence of HCVAb was considered to have been responsible for the development of hepatocellular carcinoma in chronic schistosomiasis patients. The role of HBV infection in the development of hepatoma in schistosomiasis patients was not confirmed after an assay for HCVAb was included in the study. (+info)
Identification of a novel eosinophil chemotactic cytokine (ECF-L) as a chitinase family protein.
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A novel eosinophil chemotactic cytokine (ECF-L) was purified from the culture supernatant of splenocytes of mice by a combination of anion-exchange chromatography, Procion red-agarose affinity chromatography, size exclusion high performance liquid chromatography (HPLC), and reverse phase HPLC. The NH(2)-terminal amino acid sequence was determined by direct protein sequencing. An ECF-L cDNA clone of 1,506 nucleotides was isolated from a cDNA library, and the nucleotide sequence predicted a mature protein of 397 amino acids. A recombinant ECF-L showed a level of eosinophil chemotactic activity comparable with that of natural ECF-L, and the activity was inhibited by a monoclonal antibody to ECF-L. ECF-L also attracted T lymphocytes and bone marrow polymorphonuclear leukocytes in vitro, whereas it caused selective extravasation of eosinophils in vivo. ECF-L mRNA was highly expressed in spleen, bone marrow, lung, and heart. A comprehensive GenBank data base search revealed that ECF-L is a chitinase family protein. ECF-L retains those amino acids highly conserved among chitinase family proteins, but Asp and Glu residues essential for the proton donation in hydrolysis were replaced by Asn and Gln, respectively. Although ECF-L contains a consensus CXC sequence near the NH(2) terminus akin to chemokine family proteins, the rest of ECF-L shows poor homology with chemokines. (+info)