Antimalarial activity of thiophenyl- and benzenesulfonyl-dihydroartemisinin

Each diastereomer of 10-thiophenyl- and 10-benzenesulfonyl-dihydroartemisinin was synthesized from artemisinin in three steps, and screened against chloroquine-resistance and chloroquine-sensitive Plasmodium falciparum. Three of the four tested compounds were found to be effective. Especially, 10 beta-benzenesulfonyl-dihydroartemisinin showed stronger antimalarial activity than artemisinin.

Analysis of 205 Cases of Parasite Infection Confirmed in Clinical Specimens / 대한임상미생물학회지

BACKGROUND: We analysed 205 cases of parasitic infection that were confirmed at Dept. of Parasitology, Hanyang University, College of Medicine from January 1986 to December 2003. METHODS: Parasitic worms were observed on gross examination or light microscope after treatment with lactophenol. Stool was examined with formalin-ether method for detection of eggs or protozoal cysts and scotch tape method was used for E. vermicularis eggs. In case of S. stercoralis, stool sample was incubated at 26degrees C for 48 to 72 h to confirm filariform larvae. Commercial ELISA kit for T. canis and ELISA test with hydatid cystic fluid from a patient were evaluated. Tissues were stained H&E after 10% formalin fixation and observed under the light microscope. RESULTS: There were detected 31 species of parasite among 205 specimens. Nematodes of 84 cases (41.5%), Anisakis sp., P. decipiens, E. vermicularis and T. callipaeda, visceral larva migrans, T. trichiura, A. lumbricoides, S. stercoralis, cutaneous larva migrans, Mammomonogamus sp. were observed. Cestodes of 41 cases (21.0%), D. latum, sparganum, T. saginata, cysticercus cellulosae, hydatid cyst and trematodes of 34 cases (16.6%), C. sinensis, M. yokogawai, P. westermani and N. seoulense were noted. Protozoa of 34 cases (16.6%), E. histolytica, E. dispar, T. vaginalis, Plasmodium sp. G. lamblia, E. coli, E. nana, P. carinii and arthropoda of 11 cases (5.4%), I. nipponensis, P. pubis, T. floricolum and Culex sp. larva were classified. CONCLUSIONS: Food-borne parasitic infections were distinctly noted in this analysis. And raw food or water are important as a source of parasitic infection in the future.

Diagnosis of Parasitic Infection by ELISA test / 대한임상미생물학회지

BACKGROUND: ELISA test is commonly used for diagnosis of parasite infection. This experiment was performed for detecting positive sera against Clonorchis sinensis, Paragonimus westermani, cysticercus, sparganum, Aisakis larvae, Toxoplasma gondii and Trichomonas vaginalis in patient's sera with ELISA and Western blot analysis. METHODS: Two hundred sera were collected from clinical laboratory of Hanyang University Hospital(Seoul, Kuri). Antigens of parasites were prepared from rabbit (C. sinensis), dog (P. westermani), hog (cysticercus, from Yonsei University), patient (sparganum), mackerel (Anisakis larvae), mouse (T. gondii), cultivation in Trypticase-Yeast extract-Maltose medium (T. vaginalis). ELISA and Western blot was conducted with several parasite antigens and patient's sera. RESULTS: Positive antibody titers of P. westermani, Anisakis, C. sinensis were observed 12.7%, 11.0%, and 7.0% of patient's sera, respectively. Nineteen sera among 200 patients showed cross reactions with other parasites. On Western blot, there were several antigenic bands with patient's sera, i.e., 3/5 sera of C. sinensis, 2/2 sera of P. westermani, 1/4 sera of sparganum, and 0/4 sera of cysticercus. COCLUSIONS: ELISA is a convenient method for detecting parasite infections. But purification of antigens is necessary and Western blot analysis may reduce the false positive reactions of infection.

Present Status of Human Paragonimiasis and Intestinal Parasitic Infection in Bokildo (Islet), Korea / 감염

BACKGROUND: Bokildo (Islet) has been well known as an endemic area of paragonimiasis in Korea, and still crayfishes caught from this area are used as source of intermediate host of experimental paragonimiasis. For the reason, this study was carried out to elucidate the present status of human paragonimiasis in this region and intestinal parasitoses were studied at the same time. METHODS: From June 9 to June 12, 1999 authors visited Buyong-ri and Buwhang-ri which are located in the endemic area. All possible inhabitants including nursery children, primary and middle school children were examined by intra-dermal skin test with veronal buffered saline (VBS) antigen of Paragonimus westermani and Clonorchis sinensis. Sputa were collected from 22 adults of positive reactors. Stool examination was done for the intestinal parasites, and anal swabs with adhesive tape for the pinworm were carried out simultaneously. RESULTS: Overall positive rate in skin test was 9.5% in inhabitants, and higher rate was observed in older age groups. On microscopic examination of sputa for pargonimiasis, 2 egg-positive cases from 55-year old man and woman were detected. Prevalence rate of intestinal parasites was 7.8% (26/332) and the most predominant infected parasite was Trichuris trichiura (4.2%). The pinworm infection rate was 29.7% (nursery school children 30.0%, primary school children 29.6%, respectively). CONCLUSION: Through this study human paragonimiasis was confirmed and the life cycle of Paragonimus westermani was known to be maintained continuously in this region. Meanwhile control of intestinal parasites should be performed, especially in school children.