Publications by authors named "Woon Mok Sohn"

Sigma-class glutathione transferase (GST) proteins with dual GST and prostaglandin synthase (PGS) activities play a crucial role in the establishment of Clonorchis sinensis infection. Herein, we analyzed the structural and enzymatic properties of sigma-class GST (CsGST-σ) proteins to obtain insight into their antioxidant and immunomodulatory functions in comparison with mu-class GST (CsGST-μ) proteins. CsGST-σ proteins conserved characteristic structures, which had been described in mammalian hematopoietic prostaglandin D2 synthases.

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It is uncertain when the head collar and collar spines of Isthmiophora hortensis (Digenea: Echinostomatidae), a zoonotic echinostome species in Far Eastern Asia, develop during its larval stages. In this study, the appearance of the head collar and collar spines was studied using light and scanning electron microscopy in cercariae and metacercariae experimentally obtained from freshwater snails (Lymnaea pervia) and tadpoles (Rana nigromaculata), respectively. The cercariae were shed from the snail on day 30 after exposure to laboratory-hatched miracidia.

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Epigenetic writers including DNA and histone lysine methyltransferases (DNMT and HKMT, respectively) play an initiative role in the differentiation and development of eukaryotic organisms through the spatiotemporal regulation of functional gene expressions. However, the epigenetic mechanisms have long been suspected in helminth parasites lacking the major DNA methyltransferases DNMT1 and DNMT3a/3b. Very little information on the evolutionary status of the epigenetic tools and their role in regulating chromosomal genes is currently available in the parasitic trematodes.

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This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87 species were examined over a period of 10 years (2011-2020).

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A high prevalence of Echinostoma mekongi infection (13.9%; 260/1,876) was found among schoolchildren and adults in Kandal Province, Cambodia, by fecal examination, worm expulsion, and molecular analysis of cox1 and nd1 genes. The source of infection was consumption of Pila sp.

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Standard- and large-sized eggs of Trichuris trichiura were found in the feces of schoolchildren in Yangon, Myanmar during epidemiological surveys and mass deworming with albendazole in 2017-2019. The standard-sized eggs were identified as those of T. trichiura, but it was necessary to exclude the possibility of the large-sized eggs belonging to Trichuris vulpis, a dog whipworm.

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Article Synopsis
  • Opisthorchis viverrini infection is a growing health concern in Cambodia, particularly in the central and southeastern regions, but its impact in northern areas near Laos is not well understood.
  • A study conducted on 1,101 individuals across 10 villages in Preah Vihear and Stung Treng used fecal examinations to assess the prevalence of this infection, with an egg positivity rate of around 65% in both provinces.
  • The research found a significant presence of adult O. viverrini flukes, with a total of 315 specimens collected, indicating that these provinces are highly endemic for this parasitic infection, along with some instances of mixed infections with other helminths.
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Pathogenic helminths have evolved mechanisms to preserve reproductive function while surviving long-term in the host via robust protective responses. A protective role of antioxidant enzymes in preventing DNA degradation has long been proposed, but little evidence has been provided. Here, we show that omega-class glutathione transferases (GSTOs) are critical for maintaining viability by protecting the reproductive cell DNA of the carcinogenic liver fluke, .

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  • * Researchers discovered that the CsPmy from the parasite Clonorchis sinensis interacts with human complement protein C9, pinpointing the C-terminus as the specific binding region.
  • * The study highlighted that certain fragments of CsPmy can effectively block the polymerization of C9, suggesting that CsPmy plays a key role in helping the parasite evade the host's immune response by disrupting complement activation.
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is a carcinogenic liver fluke that causes clonorchiasis in humans. Clonorchiasis is prevalent in East Asian countries, and approximately 15–20 million individuals are estimated to be infected with this fluke globally. This review highlights the current status of and clonorchiasis in Korea from the epidemiological perspective involving the analysis of humans and intermediate hosts.

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Human Pseudoterranova decipiens larval infections were diagnosed by molecular analysis of mitochondrial cox1 and nd1 genes in 12 health check-up patients in South Korea during 2002-2020. Based on high genetic identity (99.3%-100% for cox1 and 96.

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The infection nature of Clonorchis sinensis metacercariae (CsMc) in freshwater fish hosts is closely related to the transmission of human clonorchiasis. This article reviewed the infection characteristics of CsMc in freshwater fish in the Republic of Korea (Korea). The status of CsMc infection was examined in a total of 17,792 cyprinid fish of 49 species in 9 water systems, which included Hantan-/Imjin-gang, Han-gang, Geum-gang, Mangyeong-gang, Yeongsan-gang, Tamjin-gang, Seomjin-gang, Nakdong-gang, and streams in the east coastal areas from 2010 to 2020.

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Soil-transmitted helminth (STH) infections are still a considerable challenge in Myanmar. We undertook a control program for STH infections (especially Trichuris trichiura) among schoolchildren in Myanmar using mass drug administration (MDA) and health education. Around 1,700 schoolchildren from 15 primary schools in 3 suburban districts (Shwe Pyi Thar, Twantay, and Kyauktan) of the Yangon Region were subjected in this study during 2017-2019.

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Article Synopsis
  • Apical membrane antigen-1 (PfAMA-1) is a key candidate for malaria vaccines, but genetic diversity in global strains poses challenges for developing effective vaccines.
  • In a study of 131 malaria isolates from Vietnam, researchers identified 37 distinct haplotypes with most genetic variations occurring in specific protein domains.
  • The Vietnamese isolates exhibited lower genetic diversity than those from other regions and showed signs of natural purifying selection, which could inform future vaccine design targeting PfAMA-1.
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  • Research was conducted on Opisthorchis viverrini metacercariae (OvMc) prevalence in fish from three regions along the Mekong River in Cambodia between 2017 and 2020.
  • A total of 295 freshwater fish were analyzed, revealing varying infection rates: Phnom Penh had a 23.7% infection rate, Takeo 38.1%, and Kandal 90.2%, with Kandal showing particularly high infection intensities.
  • The study concluded that numerous fish species in these regions are commonly infected with OvMc, highlighting the need for preventive measures to reduce the risk of human infection in Cambodia.
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The endemicity of zoonotic trematode metacercariae (ZTM) was investigated with total 871 freshwater fishes (19 species) from Deokcheon-gang (a branch stream of Gyeongho-gang) in Sancheong-gun, Gyeongsangnam-do, Korea for 3 years (2018-2020). All fishes were examined with the artificial digestion method. The metacercariae of Clonorchis sinensis (CsMc) were detected in 233 (36.

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  • The study investigated the presence of Gnathostoma spinigerum larvae in Chinese edible frogs (Hoplobatrachus rugulosus) and striped snakehead fish (Channa striata) purchased from local markets in three regions of Cambodia between May 2017 and April 2019.
  • The examination revealed that 60% of the frogs from Phnom Penh were infected with advanced 3rd-stage Gnathostoma larvae, while no larvae were found in frogs from Takeo or in any of the snakehead fish sampled.
  • This research confirms that H. rugulosus from Phnom Penh can serve as a second intermediate host for G. spinigerum, although the infection levels were lower than previously observed in other areas.
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The infection status of zoonotic trematode metacercariae (ZTM) was investigated in total 568 freshwater fishes (19 species) from the irrigation canal of Togyo-jeosuji (Reservoir) in Cheorwon-gun, Gangwon-do, the Republic of Korea for 3 years (2018-2020). All fishes were examined using the artificial digestion method. The metacercariae of Clonorchis sinensis (CsMc) were detected in 180 (43.

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Article Synopsis
  • * A total of 927 fish were studied, revealing various levels of infection among different species, with Clonorchis sinensis and Metagonimus spp. being the most prevalent.
  • * Overall, the infection rates of zoonotic trematode metacercariae in these fish are relatively low, but certain species, like Pungtungia herzi and Sarcocheilichthys variegatus wakiyae, showed higher infection levels of Clonorchis sinensis
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, a high-risk pathogenic human liver fluke, provokes various hepatobiliary complications, including epithelial hyperplasia, inflammation, periductal fibrosis, and even cholangiocarcinogenesis via direct contact with worms and their excretory-secretory products (ESPs). These pathological changes are strongly associated with persistent increases in free radical accumulation, leading to oxidative stress-mediated lesions. The present study investigated infection- and/or carcinogen -nitrosodimethylamine (NDMA)-associated fibrosis in cell culture and animal models.

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Human infection with Taenia asiatica or a hybrid between Taenia saginata and T. asiatica has not been reported in Cambodia. We detected for the first time a hybrid form between T.

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The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yongjeon-cheon (a branch of Nakdong-gang) located in Cheongsong-gun, Gyeongsangbuk-do, the Republic of Korea (Korea). A total of 750 fishes in 19 species were examined by the artificial digestion method for 2 years (2019 and 2020). CsMc were detected in 378 (51.

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Echinostoma mekongi was reported as a new species in 2020 based on specimens collected from humans in Kratie and Takeo Province, Cambodia. In the present study, its metacercarial stage has been discovered in Filopaludina martensi cambodjensis snails purchased from a local market nearby the Tonle Sap Lake, Pursat Province, Cambodia. The metacercariae were fed orally to an experimental hamster, and adult flukes were recovered at day 20 post-infection.

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The infection status of zoonotic trematode metacercariae (ZTM) was surveyed in freshwater fishes from the water systems of Geum-gang (River) in the Republic of Korea (Korea). A total of 1,161 freshwater fishes from 6 local sites of Geum-gang were examined with the artificial digestion method for 4 years (2012-2015). Clonorchis sinensis metacercariae were detected in 122 (37.

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Article Synopsis
  • The Chinese liver fluke, Clonorchis sinensis, affects around 35 million people mainly in East Asia and leads to clonorchiasis, which can result in serious liver conditions including cholangiocarcinoma.
  • Current treatment often relies on the drug praziquantel, but there's concern about the development of drug resistance, prompting the need for new therapeutic options.
  • Researchers are focusing on improving the genome sequencing of C. sinensis to create a high-quality reference genome, which could help identify new drug targets and advance studies on the fluke and its related diseases.
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