The sensitivity and specificity of crude and affinity-purified antigens of Clonorchis sinensis obtained from the infected rabbits were studied. Stage-specific antigenic proteins from the eggs, metacercariae and adult worms were characterized by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent assay (ELISA) The results were as follows: The antibody-binding antigen (ABA) purified from whole worm crude antigen (WWA) by CNBr-activated Sepharose 4B affinity chromatography made 4 specific bands against rabbit anti-sera on Ouchterlony gel diffusion plate, while WWA made 7 bands. Major WWA protein bands by SDS-PAGE were found at 16,300-18,500 and 28,000-29,000 daltons, while major ABA protein bands were at 18,000-21,000 and 29,000-31,000 daltons. The reactivity of ABA with rabbit anti-sera in ELISA was remarkably less sensitive than that of WWA. Molecular weights of egg antigen (EGA), metacercarial antigen (MEA) and adult worm antigen (WWA) of C. sinensis ranged from 15,000-200,000 daltons, 15,000-100,000 daltons and 11,000-80,000 daltons, respectively. Major WWA proteins consisted mainly of polypeptide bands of low molecular weight, less than 31,000 daltons, while those of EGA and MEA consisted of higher molecular weights than 30,000 daltons. The ELISA reactivities of WWA to rabbit anti-sera were remarkably greater than those of MEA. EGA showed negative reaction throughout the experiments. WWA showed higher optical density (O.D.) than 1.0, when reacted with rabbit anti-sera obtained at 4-6 weeks after the infection. In the rabbit anti-sera later than 12 weeks after the infection, the O.D. reacting with WWA showed a plateau without variation. MEA showed relatively low O.D. values (<0.6), when reacted with anti-sera from lightly infected groups throughout the experiments, although there were some weak positive cases (O.D.>0.6) in heavily infected groups. MEA reacted with rabbit anti-sera showed negative results on Ouchterlony gel diffusion plates. Summarizing the above results, it is suggested that the whole worm antigen prepared from the adult worms of C. sinensis is most highly antigenic. However, this antigen might reveal cross reactions with other trematodes such as Paragonimus westermani, therefore, purification of antigenic proteins from the crude antigen is essential to increase the sensitivity and specificity for the immunodiagnosis of clonorchiasis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; rabbit ; immunology ; diagnosis ; antigen

The present work was to localize and isolate the anthelmintic substance from stem cortex of Machilis thunbergii which grows in all parts of the Korea peninsula. The dried M. thunbergii bark was extracted with a solvent mixture (Methanol: Ethyl acetate/1:1) by a Soxhlet extractor at 70C for 24 hours, and then the extract was separated into solid matter (negative wormicidal) and benzene extract (positive wormicidal) by benzene solvent. The anthelmintic action was observed on the cercaria, the liberated metacercaria and the adult of Clonorchis sinensis. On the silica gel thin layer chromatography with a spot of benzene extract in benzene solvent, nine spots were observed in iodine chamber and the spot of Rf. 0.16 value of them appeared the most strong wormicidal effect on the cercaria and the liberated metacercaria of C. sinensis. Afterward, a 0.3 g colourless solid substance which was equivalent to the Rf. 0.16 value spot was isolated from the benzene extract of 3 kg M. thunbergii stem cortex by means of silica gel column chromatography using benzene carrier, and the adult of C. sinensis was killed within 6 minutes by 0.05 percent solution of the substance.
parasitology-helminth-trematoda-Clonorchis sinensis ; chemotherpay-clonorchiasis ; rabbit ; liver ; Machilis thunbergii

The indirect fluorescent antibody test was performed to demonstrate the antibody production in the rabbits immunized with free-living amoebas; Acanthamoeba culbertsoni and Naegleria fowleri, and antibody titer changes by immunization duration. Rabbits were immunized with Acanthamoeba culbertsoni and Naegleria fowleri which were cultured axenically in CGVS medium. For experiments, rabbits were divided into two groups; small dose group received 10(4) intravenously with live or dead free-living amoebas trophozoites as an immunizing dose three times with one week interval, and large dose group received 10(6) live or dead trophozoites respectively. The control group received physiologic saline or medium for culture of free-living amoebas intravenously. Antiserum was collected 4 times at interval of 3 days in the first 10 days, and also up to 2 months later. In the group immunized with live Acanthamoeba culbertsoni, fluorescent antibody titer was higher than in the group of dead one, and also in the large dose group than in the small dose group. Antibody titer of anti-Naegleria fowleri serum in the large dose group showed no difference by the source of amoeba antigen; live or dead. But in the small dose group, antibody titer was higher in the immunized with live Naegleria fowleri than in the group with dead one. No cross reactivity was demonstrated between the Acanthamoeba and Naegleria. And no cross reaction was observed when the free-living amoebas antigens were tested against human sera of amoebiasis, paragonimiasis and clonorchiasis.
parasitology-protozoa ; free-living amoeba ; Acanthamoeba culbertsoni ; Naegleria fowleri ; immunology ; fluorescence ; rabbit ; amoebiasis ; paragonimiasis ; clonorchiasis

Authors carried out experimental study on chemotherapy with oral administration of Dithiazanine iodide (D.I.) and Bithionol sulfoxide(B.S.) in rabbit clonorchiasis. And the following result was obtained. In change of the E.P.G (eggs per gram feces) by D.I. administration, it was rather increased in early stage of the administration than prior to administration, and thereafter decreased gradually. In the change of the C.S. worm body by D.I. administration, there was not only prominent change of supporting tissue but also the change of reproductive organ was found. In considering the wormicidal effect of D.I. from detecting rate of survival worms, the effect was slight in group of 100 mg(80 mg/kg) per day dosage, but the effects were very excellent and almost complete by proper times of administration in groups of 200 mg (130 mg/kg) per day or higher dosage. But the side effect and intoxication sign of D.I. were appearent in groups of 200 mg or higher dosage. By B.S. administration, E.P.G. was decreased gradually. In changes of the C.S. worm body by B.S. administration, prominent inhibitory chnnge was seen in egg formation ability. Slight wormicidal effect of B.S. was observed in groups of 140 mg (100 mg/kg) per day or higher dosage. Side effect and intoxication sign of B.S. were found little in groups of 140 mg or lesser dosage.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; chemotherapy ; Dithiazanine iodide ; Bithionol sulfoxide ; rabbit

The rabbits were infected with Clnorchis sinensis and were treated with praziquantel at the dose of 50 mg/kg x 2 x 2 days afer 1, 2, 4, 8 weeks and 7 months from the infection. Their livers were observed histopathologically 1, 4 and 12 weeks after treatment. The findings are summarized as below: The changes of the liver in control rabbits were relatively mild until 2 weeks after infection. However, widening and thickening of bile ducts, proliferation of biliary epithelium and periductal fibrosis were moderate after 4 weeks from infection and those changes were severe after 8 weeks and 7months. Goblet cell metaplasia was found after 8 weeks from infection. The mild changes of 2-week infection group were completely recovered by 4 weeks after the treatment. In the groups of 4 or more weeks after infection, the changes of bile ducts became milder in the degree after the treatment, but were still found 12 weeks after the treatment. As the infection duration was passed, more severe changes were observed after the treatment. In this context, it is concluded that the liver changes of acute clonorchiasis in the early two weeks are reversible by treatment while chronic biliary epithelial changes are irreversible. Therefore, early treatment should be recommended as possible to minimize the remaining histopathological changes of liver in clonorchiasis.
parasitolgy-helminth-trematoda ; Clonorchis sinensis ; liver ; clonorchiasis ; chemotherapy ; praziquantel ; pathology ; rabbit

In order to find a highly efficient compound against Clonorchis infection, the anthelmintic activity of disophenol, Tremerad (SYD-230), dithiazanine iodide, dehydroemetine-late-release tablets(RO 1-9334/20), niridazole (Ambilhar), hexachlorophene (G-11), Hetol(1, 4-bis-trichloromethylbenzol) and Bilevon (niclofolan) was tested against Clonorchis sinensis experimentally infected rabbits. All drugs showed a progressive increase in efficacy as the dose rate. They were highly efficient against Clonorchis infection if sufficiently high, potentially toxic doses were given. The efficacy was evaluated by the number of detected worms with vital condition at autopsy after the treatment with above drugs. The high efficacy was observed at the following dose rates of each drugs, i.e. disophenol at a single dose of 30 mg/kg, Tremerad at the daily dose of 200 mg/kg for 10 consecutive days, dithiazanine iodide at the daily dose of 50 mg/kg for 6 consecutive days, dehydroemetine at the daily dose of 10 mg/kg for 10 consecutive days, hexachlorophene at the daily dose of 20 mg/kg for 10 to 15 consecutive days, Hetol at the daily doses from 50 to 100 mg/kg for 5 to 10 consecutive days, and Bilevon at a single dose of 8 mg/kg. Moderate effectiveness was shown in niridazole at the dose of 25 mg/kg for 10 days medication. The use of these anthelmintics for the clinical treatment of Clonorchis sinensis infection is discussed.
parasitology-helminth-trematoda ; chemotherapy-Clonorchis sinensis ; clonorchiasis-rabbit ; disophenol ; Tremerad (SYD-230) ; dithiazanine iodide ; dehydroemetine-late-release tablets(RO 1-9334/20) ; niridazole (Ambilhar) ; hexachlorophene (G-11) ; Hetol(1, 4-bis-trichloromethylbenxol) ; Bilevon (niclofolan)