Intestinal Parasite Infections among Inhabitants in Yanbian Prefecture, Jilin Province, China.

To investigate the prevalence of intestinal parasite infections in Yanbian Prefecture, Jilin Province, China, epidemiological surveys were conducted on a collaboration basis between the Korean Centers for Disease Control and Prevention and the Yanbian Center for Disease Control and Prevention. A total of 8,396 (males 3,737 and females 4,659) stool samples were collected from 8 localities and examined with the formalin-ether sedimentation technique, and additionally examined with the cellotape anal swab to detect Enterobius vermicularis eggs. The overall rate of intestinal parasites was 1.

A new method for estimating the prevalence of clonorchiasis in Korea: A proposal to replace arbitrary riverside sampling.

South Korea presently uses an arbitrary sampling method to monitor the prevalence of Clonorchis sinensis infection in the endemic areas of the country. However, the present method is not standardized and focuses primarily on individuals who reside nearest to the mainstream river. We propose a new sampling method that combines cluster sampling with proportionate quota sampling to ensure that the entire endemic area is accurately represented.

Development of a Diagnostic Kit to Detect Cryptosporidium parvum and Giardia lamblia.

Objectives: This study aims to develop a high-sensitivity antibody diagnostic kit that will enable a rapid and accurate detection of Cryptospofidium parvum and Giardia lamblia in patients with diarrhea.

Methods: The cultivated C. parvum oocysts and G.

Influencing factors for cure of clonorchiasis by praziquantel therapy: infection burden and CYP3A5 gene polymorphism.

Chemotherapy of clonorchiasis with praziquantel (PZQ) is effective but about 15% of treated cases have been reported uncured. The present study investigated correlation of single nucleotide polymorphisms (SNPs) of the cytochrome P450 gene, CYP3A5 and cure of clonorchiasis. A total of 346 egg passing residents were subjected and treated by 3 doses of 25 mg/kg PZQ.

Single nucleotide polymorphisms of cytokine genes are associated with fibrosis of the intrahepatic bile duct wall in human clonorchiasis.

This study examined the association of cytokine gene polymorphisms with intrahepatic bile duct wall fibrosis in human clonorchiasis. A total of 240 residents in Heilongjiang, China underwent ultrasonography, blood sampling, and stool examination. Single nucleotide polymorphism (SNP) sites for IFN-gamma (+874 T/A), IL-10 (-1,082 G/A, -819 C/T, -592 C/A), TNF-alpha (-308 G/A), and TGF-beta1 (codon 10 T/C, codon 25 G/C) genes were observed with the TaqMan allelic discrimination assay.

Keratitis by Acanthamoeba triangularis: report of cases and characterization of isolates.

Three Acanthamoeba isolates (KA/E9, KA/E17, and KA/E23) from patients with keratitis were identified as Acanthamoeba triangularis by analysis of their molecular characteristics, a species not previously recognized to be a corneal pathogen. Epidemiologic significance of A. triangularis as a keratopathogen in Korea has been discussed.

Changing patterns of serum and bile antibodies in re-infected rats with Clonorchis sinensis.

Rats develop strong resistance to re-infection and super-infection by Clonorchis sinensis. The present study investigated the antibodies present in the sera and bile juice of rats that were primary infected and re-infected with C. sinensis.

Factors in the resistance of rats to re-infection and super-infection by Clonorchis sinensis.

Rats develop resistance to re-infection by Clonorchis sinensis while humans do not. We investigated factors involved in the development of resistance to re-infection and super-infection in rats. Sprague-Dawley rats were infected by C.

Morphological observations of Echinochasmus japonicus cercariae and the in vitro maintenance of its life cycle from cercariae to adults.

The cercaria morphology of Echinochasmus japonicus was investigated using light and scanning electron microscopy. Cercariae, liberated from naturally infected snails (Parafossarulus manchouricus), had ovoid bodies and diminutive tails. The cercaria tegument was covered with minute spines.

A case of sparganosis mimicking a varicose vein.

Recent advances in radiological and serological techniques have enabled easier preoperative diagnosis of sparganosis. However, due to scarcity of cases, sparganosis has been often regarded as a disease of other etiologic origin unless the parasite is confirmed in the lesion. We experienced a case of sparganosis mimicking a varicose vein in terms of clinical manifestations and radiological findings.

The identification of a Clonorchis sinensis gene encoding an antigenic egg protein.

The cDNA library of Clonorchis sinensis was screened for genes encoding antigenic proteins by using sera from clonorchiasis patients. A gene of 888 bp encoding a 28-kDa protein (Cs28) was cloned and found to contain a high percentage of glycine (20%), tyrosine (11%), and lysine (11%). The amino acid sequence of Cs28 showed 60% homology with the vitelline B precursor protein of Opisthorchis viverrini and of 33% homology with the vitelline B1 and B2 proteins of Fasciola hepatica.

Organ-specific antigens of Clonorchis sinensis.

This study was carried out to find out specific proteins from different organs of Clonorchis sinensis. Crude extract, organ-specific and excretory-secretory (ES) proteins were analyzed by immunoblot with infected human sera. The bands of 7- and 17-kDa were main component of intestinal fluid and ES protein and commonly found in all organspecific proteins.

Development of resistance to reinfection by Clonorchis sinensis in rats.

We investigated the induction of resistance to Clonorchis sinensis infection by prior infection in rat and hamster models. Animals were challenged with C. sinensis metacercariae, then treated with praziquantel and reinfected.

Bile duct changes in rats reinfected with Clonorchis sinensis.

This study describes an evaluation of the sonographic, cholangiographic, pathological, and immunological findings, and the protective effect shown by rats reinfected with Clonorchis sinensis. Eight experimental rat groups were, namely, a normal control, a primary infection control, a reinfection I (reinfection 7 week after treatment following 3-week infection), a reinfection II (reinfection 2 week after treatment following 8-week infection), a reinfection III (exploration of the intrahepatic bile ducts 1 week after reinfection 4 week after treatment following 4-week infection), a superinfection, a secondary infection control, and an infection following immunization group. Sonographic and cholangiographic findings showed moderate or marked dilatation of the bile duct confluence in the primary infection control, reinfection II, and secondary infection control groups.

The involvement of the cysteine proteases of Clonorchis sinensis metacercariae in excystment.

The effects of trypsin, bile, trypsin-bile, pepsin, dithiothreitol (DTT) and metacercarial excretory-secretory product (ESP) on the in vitro excystment of Clonorchis sinensis metacercariae were investigated. The majority of metacercariae excysted immediately in trypsin-bile in PBS solution, a process which was complete after 30 min of incubation. When incubated in metacercarial ESP in PBS, excystment was potentiated in the presence of 5 mM DTT, but was inhibited dose-dependently by a cysteine protease inhibitor, iodoacetic acid.

Sustained-release praziquantel tablet: pharmacokinetics and the treatment of clonorchiasis in beagle dogs.

Praziquantel is rapidly absorbed and secreted; and thus fractional doses are recommended for the treatment of cestode and trematode infections. In the present study, we developed a new praziquantel tablet formula allowing sustained-release (SRP). In vitro dissolution of SRP tablets showed that praziquantel at 300 mg/tablet combined with hydroxypropyl methylcellulose dissolved completely at a constant rate over 10 h, whereas the conventional praziquantel tablet (PZQ) was only 40% dissolved.

Specific and common antigens of Clonorchis sinensis and Opisthorchis viverrini(Opisthorchidae, Trematoda).

The antigenic characterizations and serological reactions of human liver flukes, Clonorchis sinensis and Opisthorchis viverrini, were analyzed by immunoblot. The antigenic profiles of the crude extract of Clonorchis contained major proteins of 8, 26-28, 34-37, 43, and 70 kDa, and those of Opisthorchis 34-37, 43, 70, and 100 kDa. Of these, the 8, 26-28 and 34-37 kDa bands of Clonorchis and the 100 kDa of Opisthorchis were major components of each excretory-secretory antigen.

The Kato-Katz method is reliable for diagnosis of Clonorchis sinensis infection.

We evaluated the sensitivity of three fecal examination methods, the Kato-Katz (KK) method, formalin-ether technique (FE) and direct smear, for the diagnosis of clonorchiasis. The KK method proved to be most sensitive in six groups with different egg counts. In cases of extremely light infection FE was found to be more sensitive than KK.

Characterization of partially purified 8 kDa antigenic protein of Clonorchis sinensis.

The 8 kDa antigenic protein of Clonorchis sinensis was partially purified by ammonium sulfate precipitation and subsequently by a column chromatographic steps. The purified protein was separated into 7 and 8 kDa protein bands through SDS-tricine gel electrophoresis, while the protein was found to migrate to a 8 kDa band in 7.5-15% SDS-PAGE.