Clonorchis sinensis is a liver fluke and it is the most prevalent human parasite in Korea at present. The parasite infection induces immune responses, characteristically an increased production of parasite-specific IgE in the host. Major IgE-reacting C. sinensis antigens in infected humans have been protein bands with MWs of 15, 28, 37, 45, 51, 56, 62, 66, 74, 97 and 160 KD identified by immunoblot analysis. Individual variations of the IgE binding pattern to C. sinensis antigens have also been documented. Using immune BALB/c mouse sera, IgE-reacting protein bands have been visualized with MWs of 28, 74, 86, 160 and several > 200 KD. One of the most strongly reacted C. sinensis antigenic proteins with a molecular weight of 28 KD was purified by gel filtration and preparative electrophoresis. Using a monoclonal antibody produced against the antigenic protein, the protein was localized in the parasite's intestine, and also found to be contained in excretory-secretory antigens.
Animal ; Antibodies, Monoclonal ; Antigens, Helminth/immunology* ; Antigens, Helminth/analysis* ; Clonorchis sinensis/immunology* ; Female ; Fluorescent Antibody Technique ; Human ; IgE/immunology* ; Immunoblotting ; Mice ; Mice, Inbred BALB C

Iron is an essential element for almost all living organisms. The possible role of iron for growth, adherence and cytotoxicity of Entamoeba histolytica was evaluated in this study. The absence of iron from TYI-S-33 medium stopped amebic growth in vitro. However, iron concentrations in the culture media of 21.4-285.6 microM did not affect the growth of the amebae. Although growth was not retarded at these concentrations, the adhesive abilities of E. histolytica and their cytotoxicities to CHO cell monolayer were correlated with iron concentration. Amebic adhesion to CHO cell monolayers was significantly reduced by low-iron (24.6 +/- 2.1%) compared with 62.7 +/- 2.8 and 63.1 +/- 1.4% of amebae grown in a normal-iron and high-iron media, respectively. E. histolytica cultured in the normal- and high-iron media destroyed 69.1 +/- 4.3% and 72.6 +/- 5.7% of cultured CHO cell monolayers, but amebae grown in the low-iron medium showed a significantly reduced level of cytotoxicity to CHO cells (2.8 +/- 0.2%). Addition of divalent cations other than iron to amebic trophozoites grown in the low-iron medium failed to restore levels of the cytotoxicity. However, when E. histolytica grown in low-iron medium were transferred to normal-iron medium, the amebae showed completely restored cytotoxicity within 7 days. The result suggests that iron is an important factor in the adherence and cytotoxicity of E. histolytica to CHO cell monolayer.
Animals ; CHO Cells ; Cell Adhesion/drug effects ; Cell Survival ; Cricetinae ; Cricetulus ; Entamoeba histolytica/*drug effects/*physiology ; Iron/*pharmacology

Iron is an essential element for almost all living organisms. The possible role of iron for growth, adherence and cytotoxicity of Entamoeba histolytica was evaluated in this study. The absence of iron from TYI-S-33 medium stopped amebic growth in vitro. However, iron concentrations in the culture media of 21.4-285.6 microM did not affect the growth of the amebae. Although growth was not retarded at these concentrations, the adhesive abilities of E. histolytica and their cytotoxicities to CHO cell monolayer were correlated with iron concentration. Amebic adhesion to CHO cell monolayers was significantly reduced by low-iron (24.6 +/- 2.1%) compared with 62.7 +/- 2.8 and 63.1 +/- 1.4% of amebae grown in a normal-iron and high-iron media, respectively. E. histolytica cultured in the normal- and high-iron media destroyed 69.1 +/- 4.3% and 72.6 +/- 5.7% of cultured CHO cell monolayers, but amebae grown in the low-iron medium showed a significantly reduced level of cytotoxicity to CHO cells (2.8 +/- 0.2%). Addition of divalent cations other than iron to amebic trophozoites grown in the low-iron medium failed to restore levels of the cytotoxicity. However, when E. histolytica grown in low-iron medium were transferred to normal-iron medium, the amebae showed completely restored cytotoxicity within 7 days. The result suggests that iron is an important factor in the adherence and cytotoxicity of E. histolytica to CHO cell monolayer.
Animals ; CHO Cells ; Cell Adhesion/drug effects ; Cell Survival ; Cricetinae ; Cricetulus ; Entamoeba histolytica/*drug effects/*physiology ; Iron/*pharmacology

We evaluated the efficacy of health education in reducing indoor arthropod allergens in Seoul. The mite control measures comprised the use of mite-proof mattress and pillow coverings, regular washing of potentially infested materials, maintenance of a low humidity, removal of carpets, and frequent vacuum cleaning. Cockroach control measures included trapping, application of insecticides, and protecting food. Of 201 homes enrolled in October 1999, 63 volunteers were included in a 2-year follow-up survey between April 2000 and January 2002. Before intervention, the density of mites/g of dust varied greatly; 27.1/g in children's bedding, 20/g in adult bedding, 7.2/g on the floors of children's bedrooms, 6.8/g in sofas, 5.9/g on the floors of adult's bedrooms, 3.9/g on living room floors, 3.7/g in carpets, and 1.9 mites/g on kitchen floors. The predominant mite species and house percentages infested were; Dermatophagoides farinae 93%, D. pteronyssinus 9%, and Tyrophagus putrescentiae 8%. Comparing 1999 and 2001 infestations, before and after 25 mo of education, mite abundance was reduced by 98%, from 23.7 to 0.57 mites/g of dust. In 1999, cockroaches were detected in 62% homes: 36% Blattella germanica and 35% Periplaneta spp., including 9% double infestations of B. germanica and P. americana. Following intervention, cockroach infestation rates decreased to 22% of houses in 2000 and 23% in 2001. We conclude that continuous and repetitive health education resulted in the effective control of domestic arthropods.
Tick Control/*methods ; *Pyroglyphidae ; Population Density ; *Periplaneta ; Korea ; Insect Control/*methods ; Health Education/*standards ; Environment ; Dermatophagoides pteronyssinus ; Dermatophagoides farinae ; *Blattellidae ; Animals ; Allergens/analysis

To investigate the population densities of potential malaria vectors, Anopheles species were collected by light traps in malaria endemic areas, Paju and Gimpo, Gyeonggi-do of Korea. Five Anopheles Hyrcanus sibling species (An. sinensis, An. pullus, An. lesteri, An. kleini, and An. belenrae) were identified by PCR. The predominant species, An. pullus was collected during the late spring and mid-summer, while higher population consists of An. sinensis were collected from late summer to early autumn. These 2 species accounted for 92.1% of all Anopheles mosquitoes collected, while the other 3 species accounted for 7.9%. Taking into account of these population densities, late seasonal prevalence, and long-term incubation period (9-13 months) of the Korean Plasmodium vivax strain, An. sinensis s.s is thought to play an important role in the transmission of vivax malaria in the study areas.
Animals ; Anopheles/*classification/genetics/*growth & development ; Humans ; Malaria, Vivax/transmission ; Polymerase Chain Reaction/methods ; Population Dynamics ; Republic of Korea ; Seasons

Free-living amoebae of the genus Acanthamoeba are causative agents of granulomatous amebic encephalitis and amebic keratitis. Because the virulence of Acanthamoeba culbertsoni cultured in the laboratory is restored by consecutive brain passages, we examined the genes induced in mouse brain-passaged A. culbertsoni by differential display reverse transcriptase polymerase chain reaction (DDRT-PCR). Enhanced A. culbertsoni virulence was observed during the second mouse brain passage, i.e., infected mouse mortality increased from 5% to 70%. Ten cDNAs induced during mouse brain passage were identified by DDRT-PCR and this was confirmed by northern blot analysis. BlastX searches of these cDNAs indicated the upregulations of genes encoding predictive NADH-dehydrogenase, proteasomal ATPase, and GDP-mannose pyrophosphorylase B, which have previously been reported to be associated with A. culbertsoni virulence factors.
Virulence/genetics ; Up-Regulation ; Serial Passage ; Reverse Transcriptase Polymerase Chain Reaction/methods ; Molecular Sequence Data ; Mice, Inbred ICR ; Mice ; Genes, Protozoan/genetics ; *Gene Expression Regulation ; Gene Expression Profiling/methods ; DNA, Protozoan/biosynthesis/*physiology ; DNA, Complementary/biosynthesis ; Cloning, Molecular/methods ; Brain/parasitology ; Blotting, Northern/methods ; Animals ; Amebiasis/mortality/*parasitology ; Acanthamoeba/*genetics/*pathogenicity

Cockroaches have been implicated as a cause of respiratory allergy in urban areas worldwide. IgE-reactive German cockroach proteins were identified with molecular weights (MWs) of 90, 66, 50, 43 and 36 KD by immunoblot analysis in both immune BALB/c mice and sensitized humans. Prominent IgE-reactive proteins were purified using FPLC by ion-exchange chromatography, gel filtration and hydrophobic chromatography. The N-terminal amino acid sequence of a purified protein with a MW of 66 KD on SDS-PAGE was Val-Thr-Leu-Lys-Lys(Val)-Met-Ile-Lys-Thr-Phe-Tyr. No homologous protein was found through a search of GenBank that indicated a novel IgE-reactive protein in German cockroach extract. Another purified protein with a MW of 36 KD reacted strongly with a monoclonal antibody against Bla g 2.
Amino Acid Sequence/genetics ; Animal ; Cockroaches/chemistry* ; Human ; IgE/immunology* ; Insect Proteins/isolation & purification* ; Insect Proteins/immunology* ; Insect Proteins/genetics ; Mice ; Mice, Inbred BALB C ; Tissue Extracts/chemistry*

Giardia intestinalis infections arise primarily from contaminated food or water. Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes more specifically than the known 2 genotypes recovered from humans have been developed using the intergenic spacer (IGS) region of rDNA. The IGS region contains varying sequences and is thus suitable for comparing isolates once they are classified as the same strain. Genomic DNA was extracted from cysts isolated from the feces of 5 Chinese, 2 Laotians and 2 Koreans infected with G. intestinalis and the trophozoites of WB, K1, and GS strains cultured in the laboratory, respectively. The rDNA containing the IGS region was amplified by PCR and cloned. The nucleotide sequence of the 3' end of IGS region was determined and examined by multiple alignment and phylogenetic analysis. Based on the nucleotide sequence of the IGS region, 13 G. intestinalis isolates were classified to assemblages A and B, and assemblage A was subdivided into A1 and A2. Then, the primers specific to each assemblage were designed, and PCR was performed using those primers. It detected as little as 10 pg of DNA, and the PCR amplified products with the specific length to each assemblage (A1, 176 bp; A2, 261 bp; B, 319 bp) were found. The PCR specific to 3 assemblages of G. intestinalis did not react with other bacteria or protozoans, and it did not react with G. intestinalis isolates obtained from dogs and rats. It was thus confirmed that by applying this PCR method amplifying the IGS region, the detection of G. intestinalis and its genotyping can be determined simultaneously.
Sequence Analysis, DNA ; Sensitivity and Specificity ; Polymerase Chain Reaction/*methods ; Phylogeny ; Mice ; Humans ; Giardiasis/parasitology/veterinary ; Giardia lamblia/*classification/genetics/*isolation & purification ; Genotype ; Dogs ; Dog Diseases/parasitology ; DNA, Ribosomal Spacer/*analysis ; DNA, Protozoan/*analysis/isolation & purification ; Base Sequence ; Animals

Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.
Ancylostoma/*genetics/isolation & purification ; Ancylostomiasis/*diagnosis/parasitology ; Animals ; Base Sequence ; DNA, Intergenic/genetics ; DNA, Protozoan/genetics ; DNA, Ribosomal Spacer/genetics ; Diagnosis, Differential ; Humans ; Molecular Sequence Data ; Necator americanus/*genetics/isolation & purification ; Phylogeny ; Polymerase Chain Reaction/*methods ; Sequence Alignment ; Trichostrongylosis/*diagnosis/parasitology ; Trichostrongylus/*genetics/isolation & purification

Trichostrongylus eggs observed in cellophane-thick smears are difficult, in practice, to distinguish from hookworm eggs. In order to overcome these limitations, a molecular approach was conducted. A Trichostrongylus colubriformis adult worm was obtained from a human in Laos, which was identified morphologically. ITS-1 sequence of this worm was determined, and found to be most similar with that of T. colubriformis among the Trichostrongylus spp. reported so far. Then, this sequence was compared with those of human hookworm species, Ancylostoma duodenale and Necator americanus, and species-specific oligonucleotide primers were designed. Polymerase chain reaction (PCR) using these primers evidenced specifically amplified PCR products of Trichostrongylus sp., A. duodenale and N. americanus from the eggs of each (520 bp, 690 bp, and 870 bp, respectively). A species-specific PCR technique can be developed in order to study the epidemiology of Trichostrongylus spp. and hookworms in endemic areas.
Ancylostoma/*genetics/isolation & purification ; Ancylostomiasis/*diagnosis/parasitology ; Animals ; Base Sequence ; DNA, Intergenic/genetics ; DNA, Protozoan/genetics ; DNA, Ribosomal Spacer/genetics ; Diagnosis, Differential ; Humans ; Molecular Sequence Data ; Necator americanus/*genetics/isolation & purification ; Phylogeny ; Polymerase Chain Reaction/*methods ; Sequence Alignment ; Trichostrongylosis/*diagnosis/parasitology ; Trichostrongylus/*genetics/isolation & purification