The present study was undertaken to observe the morphological changes of Clonorchis sinensis obtained from experimentally infected rats treated with praziquantel (Biltricide) which is a new anthelmintic agent with high activity against a broad spectrum of cestode and trematode species. For this study, the rats were infected experimentally with about 50 metacercariae of C. sinensis and were given praziquantel a single dose of 600 mg per kg of body weight at 5 weeks after infection. The Clonorchis worms were isolated from the bile ducts of the rats which were autopsied on the 4th day after treatment. After isolation the parasites were observed their shape and motility in the medium of 37 C physiological saline solution, and then the fine structure of the tegument of C. sinensis was studied by means of light, scanning and transmission electron microscope. The findings of the observation were compared with those of untreated parasites. The results are as follows: All the isolated worms moved actively in the medium of physiological saline solution (37 C). A majority of the parasites obtained from the treated rats showed a large balloon shaped structure on the surface between oral and ventral suckers. But such structure has never seen in the parasites obtained from control rats. By the scanning electron microscopic observation, the regular pattern of the tegumental ridges was significantly changed on the outer surfaces of parasites obtained from the treated rats as compared with those of the control rats. By the transmission electron microscopic observation, the numerous mitochondriae in the syncytial tegumental layer of the treated parasites appeared to be degenerated and formed small vacuoles, and the tegumental ridges were also degenerated and showed somewhat flattened. In the parasites obtained from the treated rats, a different size of vacuoles interspersed in the distal part of the syncytial tegument and also in subepithelial region of the urinary bladder. These vacuoles are fused each other and lead to the disruption of the apical region of syncytial tegument along the basement layer. Finally the basement layer was dislocated. So that the tegumental layer appeared as a large balloon.
parasitology-helminth-trematoda ; Clonorchis sinensis ; chemotherapy

Experimentally infected rats with 50 metacercariae of Clonorchis sinensis each were treated orally with different dosages of praziquantel. About 100 rats were divided into 8 groups in each developmental week after infection (from the first to 8th week after infection) and 24 rats served as untreated controls. In each developmental week after infection, about 15 rats divided into 4groups including control group(3 to 5 rats) were used to determine for the curative activity of praziquantel against C. sinensis. The experimentally infected rats in each developmental weeks after infection received praziquantel 1 x 100 mg/kg x 3 days , 3 x 100 mg/kg x 1 day and 3 x 100 mg/kg x 2 days. The effects of the drug were evaluated by the worm recovery rates, morphological changes of the worms and the number of eggs per gram of feces (EPG) after treatment. The feces of individual rats were collected once in a week at one week before and 4 weeks after treatment, and the number of Clonorchis eggs were examined by Stoll's egg counting method. The necropsy was performed on 4 weeks after treatment. The liver and the bile ducts were examined immediately after the dissection, and all of the worms recovered from the liver immersed in warm saline solution in a small petri dish in order to observe the motility of individual worms. After that, all worms obtained from the treated and untreated control rats were fixed in 10 percent formalin solution. The whole mount specimens were prepared by Semichon's acetocarmine stain for the study of morphlogical changes. In the treatment with dosage of 1 X 100 mg/kg for 3 consecutive days, relatively low worm recovery rates were shown in the early stages of infection than those of control groups. However there was no differences of the worm recovery rates between the later stages of infection (7 to 8 weeks after infection) and control groups. In the early stages of infection, the worms recovered in the bile ducts of each treated rats showed morphologically intact as normal control groups, however in the later stages of infection the worms showed damage of their reproductive organs such as testes, seminal receptacle and ovary etc. In the treatment with dosage of 3 X100 mg/kg X 1 day, the recovery rates of the worms in all developmental weeks after infection were considerably low and some growth inhibition of the worms were also noted. The worms recovered from the bile ducts in all developmental stages were seriously damaged in their reproductive organs, such as testes, seminal receptacle, ovary, Mehlis' gland, uterus and vitelline glands etc. The hyaline degenerations were also observed on the parenchymal tissues in the dead worms. The mean EPG values in this group were markedly reduced at the first 2 weeks after treatment. However the low values of EPG were generally noted at the 3rd to 4th week after treatment. On the other hand, in the treatment with dosage of 3 X 100 mg/kg X 2 days, no more the living worms was recovered in all developmental stages of Clonorchis . The dead worms recovered from the bile ducts were so seriously damaged that the morphological changes could not be observed. The mean EPG values in this group were markedly reduced during the first 2 weeks after treatment. At the 3rd week after treatment EPG value became negative in the most of all treated groups. No more the Clonorchis eggs were detected at the 4th week after infection, but only a very small numbers of eggs were found by the concentration method. From the above results, it is obvious that praziquantel exhibits a high degree of activity against Clonorchis sinensis in the rats, with no apparent differences in the efficacy against each developmental stage.
parasitology-helminth-trematoda ; Clonorchis sinensis ; chemotherapy-praziquantel ; rat ; praziquantel

Praziquantel(Distocide), the Korean product, was tested for its safety and efficacy in treatment of Clonorchis sinensis infection during the period from April to September, 1983 in Korea. A total of 55 egg positive cases were selected and treated with the regimen of 25 mg/kg t.i.d. for 1 day (total 75 mg/kg). The follow-up stool examination was done in 47 cases by cellophane think smear and Stoll's egg counting techniques. The 8 uncured cases were treated again with the same regimen. The laboratory tests for blood picture and liver function were done in 27 cases and compared before and after the treatment. The results obtained are as follows: After single course treatment, the cure and egg reduction rates were 83.0% and 99.1% respectively. With the second treatment, excellent results of 100% in both rates were obtained. Several kinds of side effects such as dizziness, headache, etc. were complained by 29 cases (61.7%), however, those were so mild and transient that no special treatment was necessary. No significant chang in laboratory findings was recognizable before and after the treatment. From the above results, it is concluded that Distocide is as effective and safe as Biltricide and highly recommendable in treatment of C. sinensis infection.
parasitology-helminth-trematoda ; Clonorchis sinensis ; treatment ; chemotherapy-praziquantel ; human ; praziquantel

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

Anti-Clonorchis IgG antibody levels in serum were observed by ELISA in 129 egg positive cases and in 25 controls. The antibody levels were 0.063 to 1.216 (0.325+/-0.202)in clonorchiasis cases and 0.078 to 0.670 (0.255+/-0.133) in controls. The difference was statistically significant. However, serological diagnosis of clonorchiasis was not satisfactory in lightly infected cases because of low levels of specific IgG antibody. The antibody levels were well correlated with EPG. Changes of the IgG antibody levels were not significant 12-14 days, 4 weeks and 8-9 weeks after praziquantel treatment. Seven and 13 months after treatment, the IgG antibody levels were lowered significantly. The period for serologically negative conversion after praziquantel treatment was between 9 weeks and 7 months in human clonorchiasis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; chemotherapy-praziquantel ; enzyme-linked immunosorbent assay ; IgG

The 16 cases of Clonorchis sinensis infection were divided into 6 groups, according to the method of administration of 1, 4-Bis-trichlormethyl-benzol. The number of egg-out and clinical manifestation of pre and post drug administration were observed. In all groups, the number of ova transiently increased at the early stage of treatment and followed rather abrupt decrease reaching to E.P.G. zero by Stoll's method on 4 weeks after the medication, except group 6 which showed a few ova by M.G.L. method. Subjective symptoms: fatigability, disappetite and other general complaints by the drug administration were markedly improved in all cases. Blood counts and bleeding time were within normal value before and after the treatment. Liver function test was normal during pre- and post-treatment except case No. 9. Serum alkaline phosphatase of No.9 was high level lbefore treatment, but recovered to noraml level 3 weeks later of the drug administrations. SGOT and SGPT in 10 cases examined showed normal value. The level of serum protein was not changed during observation period. Urine albumin was noted in 2 cases before medication, but they also converted to negative within 3 weeks. Serum creatinine were all normal limits. Bradycardia were noted in 2 cases during observed no significant abnormalities of EKG. Serum electrophoresis were also normal limits.
parasitology-helminth-trematoda ; Clonorchis sinensis ; chemotherapy ; 4-bis-trichlor-methyl-benzol ; Hetol

The efficacy and toxicity of 1, 4-Bis-trichlor-methyl-benzol were examined in the animal infections(rat, rabbit and mouse) of Clonorchis sinensis. The effective dosages to kill the worm in bile ducts were 1 x 150 mg/kg in rat and 5 x 150 mg/kg in rabbit. During 48 to 72 hours after the administration of the drug, the inactive posteriorly swollen worms and variously degenerated worms were observed from liver ducts, gallbladder and intestine of the experimental animals. In gall bladder of rabbits, a plenty of fragments of the worms and clewed mass of eggs were confirmed under microscope. The E.P.G. was not decreased to zero in 3 weeks observation after the administraiton of the drug except rabbit No. 9 which was treated with the dose of 5 x 250 mg/kg. Minimal congestion and mild cloudy swelling of liver were observed in the groups of mice which were given 5 x 150 kg and 3 x 500mg/kg of the drug respectively. The body weight of experimental animals showed no evidence of changes.
parasitology-helminth-trematoda ; Clonorchis sinensis ; chemotherapy ; 4-bis-trichlor-methyl-benzol ; Hetol

This special issue is devoted to a review of the current state of knowledge of clonorchiasis. Sections deal with: the biology of Clonorchis sinensis; geographical distribution, with particular regard to Korea; epidemiology; pathogenesis; clinical features; diagnosis; prevention and control; chemotherapy.
review ; parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; epidemiology ; pathogenesis ; liver ; diagnosis ; chemotherapy ; praziquantel ; control ; hetol ; di

Ever since the first intermediate host of Clonorchis sinensis was identified with Bulimus striatulus, it has been place to an important position in epidemics. One way to prevent Clonorchis sinensis is to exterminate Bulimus, which is itself the first intermediate host and there by to separate the life cycle of Clonorchis. In killing B. striatulus, nicotine sulfate and lindane have been chosen from insecticides which are widely used in farming areas. And then nicotine sulfate and lindane have been used to check their effectiveness in killing B. striatulus. In this experiment, the resistance of cercaria which parasites to B. striatulus has also been studied. Dipping method was used in the study. Nicotine sulfate and lindane have been used to check the mortality effect. Nicotine sulfate was used to check percentage of mortality in varied times. The existance of cercaria was tried only in nicotine sulfate. In the experiment of mortality effect of insecticides to B. striatulus and cercaria, the difference in killing rate and the resistance in different concentration and different length of time have been researched. It resulted as following: In the experiment with nicotine sulfate, the mortality increased with thicker concentration in the constant length of time. When compared the necessary liquid of nicotine sulfate and lindane in LD 50, nicotine sulfate was less used than lindane, but the mortality proved high. In the treatment to the same concentration of nicotine sulfate in different length of time, it proved that the longer period showed higher mortality. The mortality time required in LD 90 of nicotine sulfate was dependent on the concentration. And thicker concentration showed quicker effect. In the resistance of cercaria and B. striatulus to nicotine sulfate, the resistance of cercaria was proved to be stronger than that of B. striatulus.
parasitology-chemotherapy-helminth-trematode-Clonorchis sinensis ; Bulimus striatulus ; nicotine sulfate ; lindane

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