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Sung-Jong Hong

Publications and source records attributed to Sung-Jong Hong.

At least 19 recordsLinked to original sources
PubMed2006

Clonorchis sinensis: codon usage in nuclear genes.

Codon usage in Clonorchis sinensis was analyzed using 12,515 codons from 38 coding sequences. Total GC content was 49.83%, and GC1, GC2 and GC3 contents were 56.32%, 43.15% and 50.00%, respectively. The effective number of codons converged at 51-53 codons. When plotted against total GC content or GC3, codon usage was distributed in relation to GC3 biases. Relative synonymous codon usage for each codon revealed a single major trend, which was highly correlated with GC content at the third position when codons began with A or U at the first two positions. In codons beginning with G or C base at the first two positions, the G or C base rarely occurred at the third position. These results suggest that codon usage is shaped by a bias towards G or C at the third base, and that this is affected by the first and second bases.

Amino Acids↗
PubMed2006

Expressed sequence tag analysis of adult Clonorchis sinensis, the Chinese liver fluke.

Expressed sequence tag (EST) pools represent partial profiles of the gene expressions of organisms. In an effort to construct a Clonorchis sinensis EST pool, 2,387 ESTs were collected from an adult C. sinensis cDNA library and assembled into 1,573 clusters. Of these clusters, 1,225 ESTs (51%) were singletons and 348 clusters consisted of more than two ESTs. There were 848 clusters (54%) that shared significant identity with previously reported proteins, and of these, 401 clusters were categorized into 11 major functional protein classes. Three cDNA clones of fructose-1,6-bisphosphate (FBP) aldolase were selected from the C. sinensis EST pool and analyzed for phylogenic clustering. FBP clones encoded a complete polypeptide, which shared significant identity to those of vertebrate and invertebrate animals and clustered with those of trematodes. We believe that the EST pool described can be confidently used as a platform in multigene researches on C. sinensis gene expression.

Amino Acid Sequence↗
PubMed2005

Clonorchis sinensis: molecular cloning and localization of myosin regulatory light chain.

One cDNA clone was purified from an adult Clonorchis sinensis cDNA library, and its deduced polypeptide sequence was found to be homologous with myosin regulatory light chain (MRLC) of invertebrates and vertebrates. Two amino-acid residues, Thr and Ser, were conserved at the phosphorylation sites that regulate the function of MRLCs. Recombinant C. sinensis MRLC (rCsMRLC) protein was produced and purified from Escherichia coli, and mouse anti-CsMRLC immune sera recognized a protein of molecular weight 24 kDa from a soluble protein preparation of C. sinensis. The CsMRLC protein was immunohistochemically localized to the muscle fibers of the subtegumental muscle layer and to the muscles of oral and ventral suckers. However, the rCsMRLC protein proved to be less useful antigen for the serodiagnosis of human clonorchiasis.

Amino Acid Sequence↗
PubMed2005

Molecular and electrophysiological characterization of nucleotide-sensitive chloride current-inducing protein of Fasciola hepatica.

Nucleotide-sensitive chloride current regulating proteins (ICln's) of the chloride channels have been characterized from man and animals. An ICln of Fasciola hepatica (ICln-Fh) consisting of 231 amino acids revealed high similarities to both consensus domain of ICln's and two acidic residue-abundant patches in its C-terminus. Native ICln-Fh protein was confirmed present in F. hepatica soluble extract by immunoblotting. The recombinant ICln-Fh protein expressed in collagenase-defolliculated Xenopus oocytes induced fast rising and outward rectifying Cl- currents (I(Cln-Fh)). The recombinant ICln-Fh protein, however, did not trigger cell swelling-induced Cl- currents (I(Cl-swell)). The I(Cln-Fh) currents were significantly reduced by substituting external Cl- with gluconic acid and by externally adding cAMP. Collectively, these results suggest that ICln-Fh protein is an inducer of Cl- currents in F. hepatica.

Amino Acid Sequence↗
PubMed2005

Molecular cloning and characterization of vitelline precursor protein B1 from Clonorchis sinensis.

In trematodes, vitelline precursor proteins are required for eggshell formation. A cDNA clone of Clonorchis sinensis (CsVpB1) was selected from an EST pool, encoding a polypeptide of 245 amino acids. The CsVpB1 polypeptide demonstrated homology with vitelline precursor proteins from trematodes with high sequential identities. In a phylogenic tree, CsVpB1 clustered with trematode VpB proteins. The CsVpB1 polypeptide was found to be rich in tyrosine residues, including putative predihydroxyphenyl alanine (DOPA) residues, involved in cross-linking of the precursor proteins. Mouse immune sera were raised against a recombinant CsVpB1 protein. In adult C. sinensis, CsVpB1 protein was exclusively localized in vitelline follicles. Based on these results, the CsVpB1 cDNA is believed to encode a VpB of C. sinensis.

Amino Acid Sequence↗
PubMed2005

A human infection of Echinostoma hortense in duodenal bulb diagnosed by endoscopy.

As gastroduodenoscopy performed more frequently, case reports of human echinostomiasis are increasing in Korea. A Korean woman presented at a local clinic with complaints of abdominal pain and discomfort that had persisted for 2 weeks. Under gastroduodenoscopy, two motile flukes were found attached on the duodenal bulb, and retrieved with endoscopic forceps. She had history of eating raw frog meat. The two flukes were identified as Echinostoma hortense by egg morphology, 27 collar spines with 4 end-group spines, and surface ultrastructural characters. This report may prove frogs to be a source of human echinostome infections.

Animals↗
PubMed2004

Developmental surface ultrastructure of Macroorchis spinulosus in albino rats.

Developmental surface ultrastructure of Macroorchis spinulosus was studied by scanning electron microscopy. One-day-old juvenile fluke was leaf-shaped and bent ventrally. Body surface was covered densely with peg-like spines and with cobblestone-like cytoplasmic processes. Ciliated sensory papillae were concentrated around oral sucker. Several unciliated sensory papillae occurred equidistantly on oral sucker and acetabulum. The ciliated papillae appeared in two longitudinal lines symmetric bilaterally on dorsal surface. On adult flukes, tegumantal spines became wider in middle of the body surface. The cytoplasmic processes differentiated into more fine velvety form. It is likely that the differentiated fine cytoplasmic processes are an increased absorptive surface to adult M. spinulosus. It is suggested that single pointed tegumental spines on anterior half of the body may be supportive for this fluke to migration.

Animals↗
PubMed2003

Prevalence of intestinal parasite infections on a national scale among primary schoolchildren in Laos.

In order to investigate the epidemiological situation of intestinal parasite infections in Laos, parasitological surveys were carried out on a national scale including 17 provinces and the Vientiane Municipality. A total of 29,846 stool specimens were collected from primary schoolchildren from May 2000 to June 2002 and examined once with the cellophane thick smear technique. The cumulative egg positive rate for intestinal helminths was 61.9%. By species, the rate for Ascaris lumbricoides was 34.9%, hookworm 19.1%, Trichuris trichiura 25.8%, Opisthorchis viverrini 10.9%, Taenia spp. 0.6% and Hymenolepis spp. 0.2%. The northern mountainous regions such as Phongsaly, Huaphan or Saysomboune Province showed a higher prevalence (over 70%) of soil- transmitted helminths. The regions along the Mekong River such as Khammuane, Saravane or Savannakhet Province showed a higher prevalence (over 20%) of fish-borne parasites. On the other hand, Schistosoma mansoni eggs were detected in 1.7% of schoolchildren only in Champassak Province, a previously endemic area. The highest prevalence was noted in Phongsaly Province (96.0%) and the lowest in Bolikhamxay Province (27.5%). An additional small-scale survey by cellophane anal swab detected Enterobius vermicularis eggs in 35.7% of 451 schoolchildren aged 6-8 years in Khammuane, Vientiane, Champassak Province and the Vientiane Municipality. Meanwhile, the mean blood haemoglobin level of hookworm-infected children was not lower than that of children not infected with hookworm, suggesting that nutritional factors are more important than parasite infection per se. Nevertheless, the above results indicate that a nationwide parasite control project is necessary to reduce possible morbidity due to parasitic diseases in the country.

Child↗
PubMed2003

Molecular cloning and immunolocalization of the 17 kDa myoglobin of Clonorchis sinensis.

We purified the 17 kDa protein abundant in Clonorchis sinensis crude extracts. The N-terminal amino acid sequence of this protein was determined and an oligonucleotide probe synthesized. Using this probe, the cDNA encoding the protein was cloned and sequenced from the C. sinensis cDNA library. It was found to consist of a total of 150 amino acids and to have 41% conserved homology with the myoglobin of the trematodes Paramphistomum epiclitum and Isoparorchis hypselobagri. The gene product over-expressed in the bacterial system was purified and identified as the same molecule in the adult worms. BALB/c mouse sera raised against the adult 17 kDa protein revealed that this myoglobin was distributed throughout the parenchymal tissues except for the eggs and reproductive organs and that the protein may be involved in the survival of C. sinensis in the oxygen-depleted environment of the host.

Amino Acid Sequence↗
PubMed2003

Ultrastructural localization of phosphoglycerate kinase in adult Clonorchis sinensis.

Phosphoglycerate kinase (PGK) is an enzyme that produces one ATP molecule in the glycolytic pathway. Clonorchis sinensis is largely dependent on glycolysis for energy production. We performed immunoelectron microscopy on adult C. sinensis by using mouse immune serum raised against recombinant C. sinensis PGK. A high density of gold particles was found in the microvilli of the intestinal epithelium and in lamellae of the sperm duct. PGK was common in the somatic cells of intra-uterine eggs and in excreted products. It was localized with moderate intensity in muscular fibers of the subtegumental muscle layer, and in the myoepithelia of the intestine and excretory bladder. We suggest that PGK plays an essential role in C. sinensis energy production for movement via muscle contraction.

Animals↗
PubMed2003

Use of a recombinant Clonorchis sinensis pore-forming peptide, clonorin, for serological diagnosis of clonorchiasis.

A recombinant pore-forming peptide of Clonorchis sinensis, clonorin, was evaluated for serodiagnostic reagent of clonorchiasis by enzyme-linked immunosorbent assay detecting IgG antibody. Recombinant clonorin showed 100% specificity and low sensitivity for sera of human clonorchiasis. In contrast, C. sinensis crude antigen revealed lower specificity and higher sensitivity than recombinant clonorin did. In sera of experimental rabbits, clonorin-specific IgG antibody was increased remarkably 8 weeks after the infection and retained around level of OD(490)=0.2 for 1 year. With excellent antigenic specificity, it is suggested that the recombinant clonorin can be used as an ingredient of the cocktail antigen for serodiagnosis of clonorchiasis from early stages of the infection.

Animals↗
PubMed2003

Recovery, growth and development of Macroorchis spinulosus in albino rats.

The developmental features, growth and organogenesis of Macroorchis spinulosus were observed in albino rats. Globular and thick walled metacercariae, possessed a stylet, Y-shaped excretory bladder and extracecal testes. In albino rats, M. spinulosus showed habitat shifting. The majority of M. spinulosus reside in the jejunum for the first four days post infection (p.i.) and migrate to the duodenum at the later stage of infection. M. spinulosus grew rapidly during the first four days and reached full maturity at 14 days p.i. and later reduced in size. The ovary was separated from the genital primodium at one day p.i. The seminal vesicle appeared on the third day and divided into two sacs on the fourth day p.i. and intrauterine eggs and sperm mass were produced on the fourth day. Organogenesis and enlargement of reproductive organs governed the growth of M. spinulosus. The similarity of related species of the genus Macroorchis to M. spinulosus was discussed in consideration to developmental features.

Animals↗
PubMed2003

Effects of anti-allergic drugs on intestinal mastocytosis and worm expulsion of rats infected with Neodiplostomum seoulense.

The effects of anti-allergic drugs on intestinal mastocytosis and the expulsion of Neodiplostomum seoulense were observed in Sprague-Dawley rats, after oral infection with 500 metacercariae. The drugs used were hydroxyzine (a histamine receptor H1 blocker), cimetidine (a H2 blocker), cyclosporin-A (a helper T-cell suppressant), and prednisolone (a T- and B-cell suppressant). Infected, but untreated controls, and uninfected controls, were prepared. Worm recovery rate and intestinal mastocytosis were measured on weeks 1, 2, 3, 5, and 7 post-infection. Compared with the infected controls, worm expulsion was significantly (P < 0.05) delayed in hydroxyzine- and cimetidine-treated rats, despite mastocytosis being equally marked in the duodenum of all three groups. In the cyclosporin-A- and prednisolone-treated groups, mastocytosis was suppressed, but worm expulsion was only slightly delayed, without statistical significance. Our results suggest that binding of histamine to its receptors on intestinal smooth muscles is more important in terms of the expulsion of N. seoulense from rats than the levels of histamine alone, or mastocytosis.

Animals↗
PubMed2002

Hemolytic activity and developmental expression of pore-forming peptide, clonorin.

Peptides pore-forming in cell membrane have been identified from a wide range of animals. A putative pore-forming peptide deduced from a cDNA clone of Clonorchis sinensis (clonorin) was predicted to consist of four amphipathic alpha-helices. Clonorin contained six invariably conserved cysteine residues, identified to form three disulfide bonds. These predicted structural features are highly homologous with pore-forming peptides, the amoebapores. Recombinant clonorin showed hemolytic activity toward rabbit erythrocytes. The hemolytic activity of C. sinensis extract increased dose-dependently and was inhibited by anti-clonorin immune sera. The clonorin was expressed developmentally in juvenile and adult flukes and localized in the intestinal epithelium of adult flukes. It is proposed that, through lysing host cellular components, clonorin could enhance proteolytic digestion in the intestine of C. sinensis.

Amino Acid Sequence↗
PubMed2002

Recombinant Paragonimus westermani yolk ferritin is a useful serodiagnostic antigen.

A recombinant protein of Paragonimus westermani yolk ferritin was bacterially produced from a previously cloned complementary DNA and was used as an antigen for an enzyme-linked immunosorbent assay (ELISA) against paragonimiasis- and other helminth-infected sera to evaluate its serodiagnostic potential. The ELISA revealed that paragonimiasis westermani had 88.2% sensitivity and 100% specificity. The positive and negative predictive values of the ELISA were calculated to be 100% and 97.1%, respectively. Sera from cats experimentally infected with P. westermani began to produce immunoglobulin G antibodies against the yolk ferritin at 13 weeks after infection, which suggests that the corresponding antigen was derived from the vitellaria in accordance with maturation of P. westermani. These results indicate that the recombinant P. westermani yolk ferritin is a potent serodiagnostic reagent for paragonimiasis westermani from an early stage of the infection.

Animals↗
PubMed2002

Clonorchis sinensis: glutathione S-transferase as a serodiagnostic antigen for detecting IgG and IgE antibodies.

Human Clonorchis sinensis infection is endemic in East Asian countries. Glutathione S-transferases (GSTs) are anti-oxidant enzymes found in all living creatures as well as in trematodes. In this study, we examined the recombinant 26kDa GST protein of C. sinensis (Cs26GST) for its serodiagnostic antigenicity toward IgG and IgE antibodies by ELISA and immuno-enhanced chemiluminescence, respectively. In IgG ELISA, recombinant Cs26GST showed 33.3% sensitivity and 100% specificity for trematode-infected human sera. In the case of the IgE antibody, recombinant Cs26GST showed 50.0% sensitivity and 93.2% specificity for clonorchiasis infection. We propose that the recombinant Cs26GST is a potent serodiagnostic antigen for detecting C. sinensis-specific IgG and IgE antibodies, and that it be best used as an antigenic cocktail in combination with other antigens.

Animals↗
PubMed2002

Tegumental ultrastructures of Echinoparyphium recurvatum according to developmental stages.

The present study was performed to observe tegumental ultrastructure of Echinoparyphium recurvatum according to developmental stages. Worms (1, 3, 5 and 15-day old) were recovered from chicks experimentally infected with metacercariae from Radix auricularia coreana. One-day old worms were elongated and ventrally concave, and covered with peg-like tegumental spines except the adjacent areas of the head crown and excretory pore. Type I sensory papillae were distributed on the lip of the oral sucker, and grouped ciliated papillae were around the oral sucker. Peg-like tegumental spines were densely distributed on the anterior surface of the ventral sucker level. The ventral sucker had an aspinous tegument and no sensory papillae. Tegumental spines on the posterior surface of the ventral sucker level were sparsely distributed and disappeared posteriorly. In 3 and 5-day old worms, the tegument around the oral sucker was aspinose and wrinkled concentrically. The ventral sucker had a wrinkled tegument and many bulbous papillae. Type I sensory papillae were distributed between the bulbous papillae. Tegumental spines were spade-shaped with a terminal tip. A total of 45 collar spines including 4 end group ones on both ventral corners was alternately arranged in 2 rows. The 15-day old worms were very stout and their tegumental spines were tongue-shaped without a terminal tip. From the above results, it is confirmed that the surface ultrastructure of E. recurvatum was generally similar to that of other echinostomatid flukes. However, some features, i.e., morphological change of tegumental spines and appearance of sensory papillae on the ventral sucker according to development, and number, shape and arrangement of collar spines, were characteristic, which may be of taxonomic and bioecological significance.

Animals↗