The susceptibility analysis of Echinococcus multilocularis protoscoleces tubulin to mebendazole and RNA interference

ABSTRACTAlveolar echinococcosis, caused by the larval (metacestode) stage of the tapeworm Echinococcus multilocularis, is a lethal parasitosis of the liver prevalent in the Northern Hemisphere. For chemotherapy the benzimidazole derivatives mebendazole and albendazole were introduced, which were found to disrupt the microtubules by inhibition of the polymerization of tubulin into microtubules, and β-tubulin was determined to be the drug target molecule. In the present study, we evaluated the chemosensitivity of E. multilocularis protoscoleces tubulin to mebendazole and RNA interference in vitro, and to explore whether the molecular level and ultrastructure of E. multilocularis protoscoleces microtubules change post-mebendazole and RNA interference. We identified that mebendazole is parasitostatic to E. multilocularis protoscoleces through suppression the tubulin expression and change the flame cell morphology in molecular level, besides RNA interference indicated that β 2 tubulin is probably one of the vital tubulin gene to form the flame cell and the protonephridial system tubules (collective tubes) of E. multilocularis protoscoleces. Molecular level and ultrastructure detection were performed by reverse transcription-PCR, western blotting and transmission electron microscope. The RNA interference would be probably as a parasitocidal method to disrupt the survival of PSCs, extend that the relevant tubulin maybe as potential target for drug development against AE.

Effect of temperature on viability of human hydatid cyst & study the volume of hydatid cyst

The hydatid materials were collected and studied, so they were contained 50 fertile human hydatid cases {33 (66%) females and 17 (34%) males}. They were collected from Al-Ramadi General Hospital during the period from December, 2003 to July, 2004 .Cysts were observed in 40 (80%) from the liver, 5 (10%) from the lungs, 3 (6%) from the kidney and 2 (4%) cysts from urinary bladder. The specimens were taken from patients of different ages. The in vitro viability of protoscoleces was assessed on the basis of flame cell activity and eosein exclusion, which were considered as criteria to determine the death or viability of protoscoleces. In addition to this movement (flame cell activity), another motility like constriction – relaxation (invagination - evagination) in the protoscoleces was also noticed. Both types of movement were examined under light microscope. The motility of protoscoleces examined under effect of three different temperature degrees 25?C, 37?C, and 40?C was within 15 minutes. It showed steadily increase with rising temperature. Flame cell activity increased as high as 70.01% at 40?C, while the motility with constriction -relaxation movement increased as 100.0% at 40?C. The volumes of hydatid cysts were also studied, so they were measured. Therefore, the volumes of human hydatid cysts were the highest in the lung and this is may be due to the spongy texture of the lung tissues. There is relationship between the volumes of Hydatid cysts and the viability was recorded.

The distribution of motor proteins in the muscles and flame cells of the Schistosoma mansoni miracidium and primary sporocyst

Schistosoma mansoni eggs, miracidia and primary sporocysts were labelled with phalloidin-rhodamine to visualize filamentous actin structures. Analysis of these forms by confocal fluorescence microscopy revealed the presence of previously well-defined circular and longitudinal muscle layers. Besides these muscular layers that sustain and provide motility to these parasite forms, we found in these 3 consecutive developmental stages of the parasite previously unidentified actin-rich tubular structures. In the 3 forms, 4 actin-rich tubules could be observed by optical sectioning underneath the well-developed muscle layers. The tubules appear in pairs, transversal to the length of the parasite, and located towards the extremities. By using an anti-flame cell specific antibody we confirmed that the tubules co-localize with flame cells and also determined that the tubule core is filled with microtubules. The additional presence of myosin in these tubules strongly suggests that they are contractile structures.