Schistosoma mansoni: schistosomicidal effect of mefloquine and primaquine in vitro.

We investigated the effects of the anti-malarials mefloquine and primaquine against the juvenile and adult life stages of Schistosoma mansoniin vitro. Cercariae were incubated with 0.5 µg/ml, 1 µg/ml and 2 µg/ml mefloquine or primaquine and with 1 µg/ml praziquantel for 12h. Schistosomula, pre-adults and adults were incubated with 0.5 µg/ml, 1 µg/ml and 2 µg/ml mefloquine or primaquine and with 1 µg/ml praziquantel for 7 days. The viability status was classified as viable, damaged or dead and was checked every 3h for cercariae and every 12h for schistosomula, pre-adults and adults. Both, mefloquine and primaquine show time and dose-dependent schistosomicidal effects on the four life stages of S. mansoni. The promising in vitro effects on all stages of the blood fluke S. mansoni warrants further evaluation of both anti-malarials and their derivatives for their prophylactic and therapeutic values in early and late schistosomiasis in field trials.

Schistosomula, pre-adults and adults of Schistosoma mansoni ingest fluorescence-labelled albumin in vitro and in vivo: implication for a drug-targeting model.

SUMMARY OBJECTIVE: Bilharziosis is one of the most important helminthal infections in humans and is caused by blood flukes of the genus Schistosoma. Three different life stages of the parasite occur within the mammalian host: schistosomula located in the skin, pre-adults located in the lung and adult worms located in the portal venous system. Erythrocytes are a major source of nutrient supply for adults. However, sources of nutrition for the developing stages are still unclear. METHODS: To investigate whether schistosomula, pre-adults and adults of Schistosoma mansoni ingest human serum albumin (HSA) in vitro, these life stages were incubated with aminofluorescein-labelled human serum albumin (Afl-HSA) for 5 h. To test the uptake of albumin in vivo, the albumin conjugate was given intravenously to S. mansoni infected NMRI mice 24 h before harvesting the 3 life stages. RESULTS: In comparison to the control group schistosomula, pre-adults, and adults showed an accumulation of Afl-HSA within the oesophagus and intestinal caecum in vitro and in vivo. CONCLUSION: Our findings suggest that albumin seems to be a major source of energy supply for the early schistosomal life stages and an additive energy support for adult worms. Since albumin has been used successfully as a drug carrier for chemotherapeutic substances against malignant disorders, further studies will focus on albumin as a carrier for anthelminthics in a drug-targeting model.

[Global warming: trailblazer for tropical infections in Germany?]. / Globale Erwärmung: Wegbereiter für tropische Infektionskrankheiten in Deutschland?

Since 1850, the CO (2) content of the atmosphere has increased from 280 to 360 ppm, and the average surface temperature has risen from 14.6 to 15.3 C . A further increase between 1.8 and 4.0 C is expected for the 21st century. Temperate and cold climate zones are affected predominantly, but tropical regions are not spared. At the same time, the world wide climate effects of the "El Niño Southern Oscillation" are amplified. Global warming enhances the growth of tropical pathogens (malarial plasmodia, leishmania, yellow fever virus, dengue virus, West Nile virus, Vibrio cholerae) and vectors (anopheles, aedes, culex, and phlebotomus mosquitos; hard ticks). Global warming may lead to the emergence of diseases which at present are not endemic in Germany, like West Nile fever, Dengue fever, or Leishmaniases, and to enhanced transmission of borreliosis and tick-borne encephalitis. Malaria and cholera, in contrast, are influenced more strongly by socioeconomic factors. Improved surveillance and intensified research on the relationship between climate change and infectious diseases is needed.

[Scorpions and scorpion stings in Jordan]. / Scorpions et piqures de scorpions en Jordanie.

The scorpion fauna of Jordan consists of fourteen species belonging to three families (Buthidae, Scorpionidae and Diplocentridae), of which three species are poisonous: Leiurus quinquestriatus, Adroctonus crassicauda and Buthus occitanus. A key to all species is included. Five hundred and forty-seven cases of scorpion stings were reported during 1982-1985, including two fatalities. Clinical data for sixteen cases treated at the Jordan University Hospital are summarized. In Jordan human and cultural customs are related to scorpion stings. Sting accidents according to age groups and seasons are given.