RESUMO
The unsaponifiable part of the petroleum ether fraction of the leaves and stems of Oreopanax reticulatum Donn [Family Araliaceae] was analysed by GLC to reveal the presence of a series of hydrocarbons, cholesterol, stigmasterol and beta-sitosterol. Also, eight fatty acids were identified on the saponifiable part. The butanolic fraction was chromatographed over silica gel and sephadex-LH20 columns and preparative thin layer chromatography to afford two flavonoid glycosides [I and IV] as well as four bidesmosidic triterpenoidal saponins [II, V, VII and VIII]. Alkaline hydrolysis of two bidesmosidic saponins [II and V] gave two monodesmosidic [III and VI]. Their structures were elucidated using spectroscopic and chemical techniques. Molluscicidal screening of the isolated compounds [I-VIII] against Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni in Egypt revealed that the two monodesmosidic triterpenoidal saponins [III and VI] have strong activities [LC90= 7 and 6 ppm] after 24 hours exposure whereas the two flavonoid glycosides and four bidesmosidic saponins were inactive up to 50 ppm
RESUMO
Screening the aqueous suspensions of the dry powders of 50 Egyptian plants against Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni in Egypt, revealed that the fruits of Sapindus saponaria Burm. [Family Sapindaceae] as well as the leaves and stems of Buddleia asiatica Lour. [Family Loganiaceae] have high molluscicidal activities [LC90= 90 and 180 ppm for the two plants respectively] after 24 hours exposure times. Also, the petroleum ether, benzene, chloroform, ethyl acetate, acetone and methanol extracts of each plant were separately tested against the same snail species. Results showed that methanol, acetone, ethyl acetate and chloroform extracts of S. saponaria have activities whereas only the methanol extract of B. asiatica was active. Different ages of snails showed variable susceptibility towards the methanol extracts of both plants. Phytochemical investigation of the two plants was carried out and revealed that saponins are the major constituents in both plants so it may be responsible for the molluscicidal effectiveness of the two plants. To confirm this conclusion, the crude saponins of each of the two plants were prepared and they recorded very strong potency against B. alexandrina at 19 and 11 ppm. Also, the larvicidal potencies of the methanolic extract of each plant was tested against S. mansoni cercariae and miracidia. B. asiatica extract was lethal to both larvae at 90 ppm while 45 ppm of S. saponaria was not larvicidal at this concentration. However none of the methanol extracts of the two plants inhibited the hatchability of S. mansoni ova. Now, the two plants will be submitted to different chromatographic techniques to separate their active ingredients
RESUMO
In egypt, measles vaccination is compulsory at the age of 9 months,. The lates figures showed that the coverage rate for males vaccination was 90% in 1993. In spite of this high coverage rate, many measles cases are still seen. The study was performed on 212 children [9-17 months age, 49% males and 51% females]. Maternal antibodies, prior to immunization, were present in only 9 children [3%]. 6 months after immunization, 172 children were found to be seropositive, while 40 children were seronegative. The seroconversion rate was 81%. The seroconversion rate in urban areas was 82%, while the seroconversion rate in rural areas was 80% with no statistically significant difference between urban and rural areas. The seroconversion rate in children with upper respiratory tract infection at the time of vaccination was 83%, while the seroconversion rate in children without upper respiratory tract infection at the time of vaccination was 79% the difference was not statistically significant