A scanning electron microscopic study was performed on the surface ultrastructure of Pygidiopsis summa (Digenea: Heterophyidae) adults. Metacercariae were collected from gills and muscles of mullets (Mugil cephalus) caught in a known endemic area, and adult flukes were harvested from dogs after 8 weeks of experimental infection. The worm was calabash form with its posterior part broader than the anterior part. Tegumental spines were densely distributed over the body surface, except on the suckers and genital apparatus, and around the excretory pore. Well differentiated spines were observed on the anterior half of the body, with 14-16 tips ventrally, and 19-20 tips dorsally. On the oral sucker, three pairs of type I sensory papillae (uni-ciliated knob-like swellings) and one pair of type II sensory papillae (aciliated round-swellings) were observed on the anterior and posterior parts of the lip, respectively. On the lip of the ventral sucker, one pair of type II sensory papillae was distributed only on its posterior part. Sperms were seen emerging from or entering into the genital apparatus. The results showed that the surface ultrastructure of P. summa was unique among the heterophyid trematodes, especially in digitation of tegumental spines and in distribution of sensory papillae on oral and ventral suckers.
Animals ; Dogs ; Heterophyidae/*ultrastructure ; Microscopy, Electron, Scanning

The relationship between the intestinal histopathology and number and position of intraepithelial lymphocytes (IEL) was observed chronologically in the small intestine of rats experimentally infected with Metagonimus yokogawai. Fifteen Sprague-Dawley rats were orally infected each with 3,000 metacecariae, and 3 were kept uninfected for controls. Three rats each were sacrificed on the day 5, 10, 15, 24 and 70 post-infection (PI) and samples of the small intestine, 5 cm, 10 cm, 20 cm and 70 cm posterior to the pylorus were taken. The samples were processed routinely and stained with Giemsa. The intestinal histopathology was severe during the day 5-15 PI and characterized by villous atrophy, crypt hyperplasia, and decrease of villus/crypt height ratio. After the day 24 PI, the intestinal lesions showed some tendency of recovery. The number of IEL increased at the early stage of infection, but decreased thereafter to a lower level than that of controls, with progression of the pathological changes. Then, the IEL number began to increase again after the day 24 PI. In control rats, the great majority of the IEL were located at the basal region of the epithelium. During the early stage of infection, however, a considerable proportion of IEL was found to have moved to the intermediate or apical region of the epithelium. From the above results, it is suggested that the change of IEL number and position during the course of M. yokogawai infection should be closely related to the progression and recovery of the intestinal histopathology.
English-Abstract ; Epithelium-pathology ; Rats- ; Rats,-Sprague-Dawley ; Time-Factors ; *Heterophyidae- ; *Intestinal-Diseases,-Parasitic-pathology ; *Intestines-pathology ; *Lymphocytes-pathology ; *Trematode-Infections-pathology

We investigated the optimal culture conditions for Cryptosporidium muris in a human stomach adenocarcinoma (AGS) cell line by determining the effects of medium pH and of selected supplements on the development of C. muris. The optimum pH of the culture medium required for the development of C. muris was determined to be 6.6. The number of parasites significantly increased during cultivation for 72 hr (p < 0.05) at this level. On the other hand, numbers decreased linearly after 24 hr of incubation at pH 7.5. When cultured in different concentrations of serum, C. muris in media containing 5% FBS induced 4-7 times more parasites than in 1% or 10% serum. Of the six medium supplements examined, only 1 mM pyruvate enhanced the number of C. muris in vitro. Transmission electron microscopic observation showed the developmental stages of C. muris in the cytoplasm of the cells, not in an extracytoplasmic location. The growth of C. muris in AGS cells provides a means of investigating its biological characteristics and of testing its response to therapeutic agents. However, a more optimized culture system is needed for the recovery of oocysts on a large scale in vitro.
Adenocarcinoma ; Animals ; Cell Line, Tumor ; Cryptosporidium/*growth & development ; Culture Media ; Human ; Hydrogen-Ion Concentration ; Stomach/*parasitology ; Stomach Neoplasms ; Support, Non-U.S. Gov't

Plasmodium vivax malaria re-emerged in South Korea in 1993, and epidemics continue since then. We examined genetic variation in the region encompassing the apical membrane antigen-1 (PvAMA-1) of the parasites by DNA sequencing of the 22 re-emerging P. vivax isolates. The genotype of the PvAMA-1, which was based on sequence data previously reported for the polymorphic regions, showed that two haplotypes were present at one polymorphic site. Compared with reported data, the two types, SKOR type I and type II, were similar to Chinese CH-10A and CH-05A isolates, respectively. Thus, the present study showed that two genotypes of AMA-1 genes coexist in the re-emerging Korean P. vivax.
Adult ; Aged ; Amino Acid Sequence ; Animals ; *Antigens, Protozoan ; Base Sequence ; Child ; Female ; Genotype ; Human ; Korea ; Malaria, Vivax/*genetics ; Male ; Membrane Proteins/chemistry/*genetics ; Middle Aged ; Molecular Sequence Data ; Polymorphism (Genetics) ; Protozoan Proteins/chemistry/*genetics ; Support, Non-U.S. Gov't

A 36-year old Korean woman consulted a clinic for a regular gynecological examination, and a mass was noticed in her pelvis. She was referred to the Asan Medical Center, Seoul where transvaginal ultrasonography confirmed a pelvic mass exceeding 10 cm in diameter. She received total abdominal hysterectomy and bilateral salpingoophorectomy, and a borderline serous neoplasm with micropapillary features involving the left ovary and right ovarian serosa was histopathologically confirmed. In addition, a section of a nematode with numerous eggs was found in the parenchyma of the left ovary. The worm had degenerated but the eggs were well-preserved and were identified as those of Enterobius vermicularis. She is an incidentally recognized case of ovarian enterobiasis.
Adult ; Animals ; Enterobiasis/diagnosis/*parasitology/pathology ; Enterobius/isolation & purification ; Female ; Human ; Korea ; Ovarian Diseases/diagnosis/*parasitology/pathology ; Ovary/parasitology ; Parasite Egg Count

The intestinal histopathology and in situ postures of Gymnophalloides seoi (Digenea: Gymnophallidae) were studied using C3H/HeN and C57BL/6 mice as experimental hosts; the effects of immunosuppression were also observed. The metacercariae isolated from naturally infected oysters, 300 or 1,000 in number, were infected orally to each mouse, and the mice were killed at days 3-21 post-infection (PI). In immunocompetent (IC) mice, only a small number of flukes were found in the mucosa of the duodenum and jejunum during days 3-7 PI, with their large oral suckers pinching and sucking the root of villi. The intestinal mucosa showed mild villous atrophy, crypt hyperplasia, and inflammations in the villous stroma and crypt, with remarkable goblet cell hyperplasia. These mucosal changes were almost restored after days 14-21 PI. In immunosuppressed (IS) mice, displacement as well as complete loss of villi adjacent to the flukes was frequently encountered, otherwise the histopathology was generally mild, with minimal goblet cell hyperplasia. In these mice, numerous flukes were found, and it seemed that they were actively moving and rotating in situ. Several flukes were found to have invaded into the submucosa, almost facing the serosa. These results indicate that in IC mice the intestinal histopathology caused by G. seoi is generally mild, and the flukes do not penetrate beyond the mucosa, however, in IS mice, the flukes can cause severe destruction of neighboring villi, and some of them invade into the submucosa.
Animals ; Atrophy ; Immunocompromised Host ; Intestinal Diseases, Parasitic/*parasitology/pathology ; Intestinal Mucosa/parasitology/*pathology ; Male ; Mice ; Mice, Inbred C3H ; Mice, Inbred C57BL ; Support, Non-U.S. Gov't ; Trematoda/*pathogenicity ; Trematode Infections/*parasitology/pathology

A 15-year-old boy, who had recently arrived back from a trip to Cambodia for a missionary camp, presented with several serpiginous thread-like skin lesions that began as small papules on the left upper extremities 2 weeks before his visit to Hospital. The skin lesions were pruritic and erythematous, and had migrated to the chest and abdomen. The histopathological findings showed only lymphocytic and eosinophilic infiltrations in the dermis of the biopsied skin lesion. The patient's serum reacted strongly to the Ancylostoma caninum antigen by an ELISA method. Therefore, he was diagnosed with cutaneous larva migrans by A. caninum. After the oral administration of albendazole and ivermectin, the skin lesions resolved without recurrence. This is the first reported case of a cutaneous larva migrans caused by Ancylostoma canimum diagnosed serologically using ELISA in Korea.
Adolescent ; Ancylostoma/*immunology ; Animals ; Antibodies, Helminth/*blood ; Enzyme-Linked Immunosorbent Assay ; Humans ; Larva Migrans/*diagnosis/parasitology ; Male

There is a trial to increase as four years of the premedical course to make doctors with better humanities and variable educational backgrounds and good researchers in basic medicines. We studied the trial in the present situation of the Korean in scvcral vicwpoints There will be a confusion between doctor in a origanization and there are many problems expected with two different educational system in a countury Moreover, two years of premedical course and four years of medical course are enough to a clinician, especially a primary care doctor and there will be increased costs and late age to be a doctor if premedical course are increased as four years. It is not real reason for the lack of applicants to be good researchers in basic medicines that shot premedical course and lack of non-medical educational backgrouds. Also situation of medical school in Korea is not suffice to extend their facilities and faculties. Finally advantages from the extension of the premedical course can be gained with introductions of the limeted bachelor`s admission and or dual major system. The most important things is the single educational system to be a doctor and leaving the system to the discretion of the medical schools or universities
Education, Medical* ; Humanities ; Humans ; Korea* ; Primary Health Care ; Schools, Medical

No abstract available.
Aged ; Animals ; Diagnosis, Differential ; Dirofilaria immitis/*isolation & purification ; Dirofilariasis/*diagnosis/parasitology/surgery ; Eye Infections, Parasitic/*diagnosis/parasitology/surgery ; Female ; Humans ; Ophthalmologic Surgical Procedures ; Orbital Diseases/*diagnosis/parasitology/surgery

BACKGROUND: Although human parasitic infestations have decreased generally in Korea, Clonorchis sinensis, Paragonimus westermani, Cysticercus and Sparganum are still a serious concern due to their relatively high prevalence and severe complications. A definitive diagnosis, however cumbersome and occasionally invasive, is required in order to detect adult worms, eggs, or cysts. The parasite-specific IgG antibody (PSA) test using the ELISA method has been recently developed to diagnose and monitor the infestations of those four parasites. We analysed PSA positive patients for Clonorchis sinensis, Paragonimus westermani, Cysticercus and Sparganum. METHODS: The serum samples referred to the Neodin Medical Institute for PSA were tested by the ELISA method using crude extracts of C. sinensis, P. westermani, Sparganum and cystic fluid of Cysticercus. The PSA results during the 7-month period from January to July 2001 were retrospectively analysed. The medical records of the patients at Asan Medical Center (AMC) with positive PSA were reviewed with stool examinations for parasites, skin tests for C. sinensis and P. west-ermani, radiological findings and antiparasitic management. RESULTS: A total of 865 specimens were tested for PSA and 84 samples (9.7%) of 76 patients were positive; C. sinensis, Cysticercus, Sparganum, and P. westermani were positive in 26 patients (3.0%), 26 (3.0%), 14 (1.6%) and 10 (1.2%), respectively. 26 specimens from 18 AMC patients were positive for one or more PSA; 6 Cysticercus. 4 C. sinensis, 5 Sparganum and 3 P. westermani. All PSA-positive cases for Cysticercus, C. sinensis and P. westermani were compatible with the clinical diagnosis; however, it was difficult to elucidate in the clinical correlation of 3 out of 5 Sparganum-positive cases. CONCLUSION: Cysticercus, C. sinensis and P. westermani are currently prevalent in Korea. Positive PSA ELISA tests for Cysticercus, C. sinensis and P. westermani are reliable indicators in diagnosing present infestations among the clinically suspected patients.
Adult ; Chungcheongnam-do ; Clonorchis sinensis* ; Complex Mixtures ; Cysticercus* ; Diagnosis ; Eggs ; Enzyme-Linked Immunosorbent Assay* ; Humans ; Immunoglobulin G ; Korea ; Medical Records ; Ovum ; Paragonimus westermani* ; Parasites ; Prevalence ; Retrospective Studies ; Skin Tests ; Sparganum*