Ultrastructural studies on the integument of digenetic trematodes were investigated by several workers (Senft et al., 1961; Bjorkman and Thorsell, 1964; Burton, l966; Erasmus, l968; Morris and Threadgold, 1967, l968). Clonorchis sinensis is a common parasite of human beings in the Far East. But as far little has been written on ultrastructure of the integument of this parasite. This study was carried out systematically to elucidate the ultrastructure of the integument of adult C. sinensis, and the results are summarized as follows: The integument of C. sinensis was organized in two parts; the epidermis and the muscular layer. The apical surface and basal surface of the epidermis were covered with typical plasma membrane and irregularly invaginated from the surface. Plasma membrane at perisuckers was extremely folded and appeared as if the epidermis might be divided with the layer. The syncytial epidermis contained mitochondria and numerous secretory bodies, and which was connected by cytoplasmic processes to nucleated epidermal cells lying in the parenchyma. The mitochondriae, the secretory bodies, the granular endoplasmic reticulum, the Golgi bodies and the free ribosomes were present in the perinuclear cytoplasm of epidermal cells, but no organelle was observed in processes of epidermal cell except some secretory bodies. The fibrous layer consists of argentophile fiber and collagenous fiber, in which the circular muscle bundles and longitudinal muscle bundles were embedded. Bundles of muscle fiber are weIl developed at the perisucker, and mitochondriae in this portion contain many cristae as compared with any other parts of C. sinensis.
parasitology-helminth-trematoda-Clonorchis sinensis ; ultrastructure ; electronmicroscopy

In order to study host-parasite relationship in trematode, the susceptibility in rabbits of Clonorchis sinensis were examined. A certain number of metacercariae of C. sinensis were administered orally to rabbits, and rats and dogs were used to compare with rabbits. the results were summerized as follows: The rabbits were successfully infected with metacercariae of C. sinensis in all case of the groups given 10 to 500 each. But the highest recovery rate of the worm was 33.0 percent in the case given 100 metacercariae. In the early stage of infection, the worms were hardly found, but 10 days after the infection, the number of worms were detected easily. Three months after the infection, the recovery rate of worms was 31.3 percent in the rabbits given 300 metacercariae. The recovery rates of the worms in two months after the infection were 27.4 percent in rabbits, 51.0 percent in rats and 54.6 percent in dogs. Morphologically the body length and the body width markedly increased in the period until 10 days after the infection, and after that the genital organs began to get mature gradually while the growth of the body showed down. The measurement of adult C. sinensis recovered from the animals two months after the infection was the largest in rabbits followed by rats and the worms from dogs showed the smallest measurement.
parasitology-helminth-trematoda ; Clonorchis sinensis ; rabbit ; biology

Tegumental ultrastructures of Echinochasmus japonicus were observed by scanning electron microscopy. The worms were recovered from albino rats which were experimentally infected with the metacercariae obtained from Pseudorasbora parva. Followings are summarized findings. The worms were minute and plumpy gourd-shaped with attenuated anterior and round posterior end. The tegument of whole body was wrinkled transversely and covered with cobblestone-like cytoplasmic processes. Head crown was armed with 24 collar spines which were embedded in cytoplasmic pockets. The spines were arranged in a row with an interruption at dorsomedian line, however, the 2nd and the 4th spines were outstretched more than others. Oral and ventral suckers were muscular with numerous type II sensory papillae, and genital pore opened between the two suckers. Tegumental spines were spade-shaped with broad base and pointed tip. They were compact in ventro-lateral tegument or dorsal surface of anterior body. The were not found between the two suckers and dorsal surface of posterior body. Two types of sensory papillae, uni-ciliated (Type I) and roundly swollen sensory papillae (Type II), were observed. The type I papillae were chiefly distributed on ventral surface of tegument and type II were on the lips of suckers. Arrangement of collar spines, shape and distribution of tegumental spines or sensory papillae are regarded as characteristic features of E. japonicus.
parasitology-helminth-trematoda ; Echinochasmus japonicus ; electronmicroscopy

This study was undertaken to evaluate the role of peritoneal exudate cells in the transfer of immunity against the liver fluke, Clonorchis sinensis in the inbred BALB/c mice. Ten donor mice were divided into 2 groups. One group consisted of 5 mice was infected orally with 20 metacercariae of C. sinensis, and the other group was injected intraperitoneally with 20 excysted larvae. Thirty days after immunization, the peritoneal exudate cells were obtained from the donor mice. Twenty recipient mice were divided into 4 equal groups for the purpose of primary immunization. The mice of Group I were injected intraperitoneally with 2 x 10(6) peritoneal exudate cells of the donor mice infected orally, those of Group III were injected intraperitoneally with 2 x 10(6) peritoneal exudate cells of the donor mice injected intraperitoneally. Those of Group II were injected orally with 20 metacercariae of C. sinensis. The group IV mice served as controls. Four days after the primary immunization all recipient mice were challenged orally with 20 metacercariae of C. sinensis, and then killed 30 days after the challenging infection. When the peritoneal exudate cells were injected into the recipient mice, pronounced reduction in eggs per gram of the feces was found in the mice of Group I and Group II, but no reduction in those of Group III. In the worm burdens of C. sinensis, the number of flukes found in the mice of Group II was only significantly less than those in the control group(IV). In addition the number of plaque forming cells per spleen in the mice of Group II was found larger than those in Group I. It is likely that donor peritoneal exudate cells transferred to the recipients might result in the production of relative immunity.
parasitology-helminth-trematoda ; Clonorchis sinensis ; immunology ; mouse

As a series of systematic classification for Korean common liver fluke, Fasciola sp., karyotype was investigated by means of the modified air-drying technique and of the regular Giemsa staining, Also, C-staining method was applied for detailed karyological analysis from the germ cells of the fluke. The following is a brief summary of the leading facts gained through the experiment. Korean Fasciola sp. was classified into three types based on their chromosomal complements; individuals with 20 or 30 chromosomes and with a 20/30 mosaic constitution. Worms having 30 chromosomes represent a triploid form with 3 sets of 10 basic chromosomes, while those with 20 chromosomes were diploid and mosaic individuals were 2n/3n mixoploid. The frequency of the individual type calculated is as follows; 67.45% of 212 flukes examined was of diploid, 10.85%, triploid, and the rest, 21.7%, mixoploid, respectively. In many cases, two or three types were found in the peculiar bovine host while single type inhabitant was about 20% out of 52 cases. The twenty chromosomes consisted of 1 parir of large metacentrics, 4 pairs of medium-sized subtelocentrics, and 5 pairs of small submetacentrics, while constitution of the thirty chromosomes was nearly interpreted as a triploid form with 3 sets of 10 basic chromosomes. The high centromeric indexes of both types are the first pairs among all the examined, and 37.93% was of diploid and 47.93%, triploid, respectively. In mixoploid individuals, constitution of the chromosomes of diploid or triploid cells was the same as that of diploid or triploid individuals. All the chromosomes of the germ cells in both types showed C-band around the centromeic region and especially the chromosomes no's 3, 7, and 8 showed a remarkable C-band distinguished from other chromosomes. The variance for the sizes of the worms and the eggs were not parallel with three different genotypes in Korean common liver fluke.
parasitology-helminth-trematoda ; Fasciola sp. ; karyotype ; taxonomy

Adult Clonorchis sinensis were collected from the biliary passage of nine cases of medico-legal autopsies. The worms were washed repeatedly with tap water and rinsed twice with physiological saline. Incubation took place in Tyrode's medium in order to recover live worms. The number of worms surviving in the medium was determined. The rate of surviving worms showed an unexpectedly high percentage (22.8%) in those cases autopsied 2 days after death. The surviving worm burden dropped sharply to 6.3 and 9.2 percent for those samples taken 5 days after death.
parasitology-helminth-trematoda ; Clonorchis sinensis ; autopsy

The tegumental ultrastructures of Echinostoma hortense adults were observed by scanning electron microscopy. The worms of 4 weeks of age were harvested from albino rats experimentally infected with the metacercariae obtained from the loach. The results were as follows: The worms were leaf-like and their anterior end portion, including oral sucker and head crown, ventrally curved to face posteriorly. The tegument of whole body was wrinkled transversely and covered with cobblestone-like cytoplasmic processes. The oral sucker had roundly swollen (type II) sensory papillae on the ventral half of its lip and uni-ciliated knob-like (type I) sensory papillae, arranged in 2-3 rows, on the dorsal outer surface. Aspinous ventral sucker had many of type I papillae arranged in a circular band on its outer surface. The tegument around the genital opening was of similar feature to the ventral sucker, but sensory papillae were hardly found around the former. Scale-like spines with broad base and round tip were distributed densely on the tegument anterior to the ventral sucker but they became sparse in posterior half of the ventral surface, finally to disappear at posterior extremity. A few number of type I papillae were observed on the ventral surface. The results suggest that the tegument of E. hortense is similar to that of other echinostomes especially E. revolutum. But the number and arrangement of collar spines, and/or the type and distribution of sensory papillae seem characteristic features of E. hortense differed from other echinostomes.
parasitology-helminth-trematoda ; Echinostoma hortense ; electron microscopy

Thin layer immunoassay was carried out to demonstrate antibodies against Clonorchis sinensis in sera from clonorchiasis patients. Saline extract of adult worm was used as antigen. TIA technique was performed as described earlier by Elwing et al. (1976), but agarose was used instead of agar. The antibody titres of sera in 60 clonorchiasis cases were higher than that of 10 healthy and 10 amoebiasis cases, but not different comparing with that of 10 paragonimiasis cases. Antibody titres in clonorchiasis gave no differences according to the age, sex, EPG in feces, eosinophilia degree of blood, level of alkaline phosphatase and transaminase (SGOT, SGPT) in sera. It is suggested that, after evaluation, the TIA might supplement or be used as an alternative to other immunodiagnostic tests already in use for the diagnosis of clonorchiasis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; immunology

Thin layer immunoassay was carried out to demonstrate antibodies against Clonorchis sinensis in sera from clonorchiasis patients. Saline extract of adult worm was used as antigen. TIA technique was performed as described earlier by Elwing et al. (1976), but agarose was used instead of agar. The antibody titres of sera in 60 clonorchiasis cases were higher than that of 10 healthy and 10 amoebiasis cases, but not different comparing with that of 10 paragonimiasis cases. Antibody titres in clonorchiasis gave no differences according to the age, sex, EPG in feces, eosinophilia degree of blood, level of alkaline phosphatase and transaminase (SGOT, SGPT) in sera. It is suggested that, after evaluation, the TIA might supplement or be used as an alternative to other immunodiagnostic tests already in use for the diagnosis of clonorchiasis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; clonorchiasis ; immunology

The egg laying capacity of Fibricola seoulensis was observed in mice and rats. In mice, the mean number of eggs produced by an adult worm a day was 116 at the first week after infection, 123 at the 2nd week and 42 at the 3rd week. Thereafter, the capacity of about 20 eggs/worm/day was maintained up to one year period. In rats, it generally produced more eggs; 49 at 1 week, 250 at 2 weeks, 216 at 4 weeks, 327 at 6 months and 11 at one year after infection. It survived longer than a year in mice and rats.
parasitology-helminth-trematoda ; Fibricola seoulensis ; egg