Publications by authors named "Hyun Joo Sohn"

Prions are infective agents composed of abnormally folded prion proteins (PrP), which are pathogenic isoforms of normal cellular prion proteins (PrP) that cause incurable, transmissible, neurodegenerative conditions in mammals called prion diseases. The spread of PrP within a host is facilitated by the lymphoreticular system, which uptakes and propagates PrP in the periphery and transmits them to the central nervous system. Our previous study showed that poly-l-arginine (PLR), a cationic amino acid polymer, inhibits PrP accumulation in neuroblastoma cells with persistent prion infection (ScN2a).

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Chronic wasting disease (CWD) is a highly contagious prion disease occurring in free-ranging and farmed cervids. CWD continues to spread uncontrolled across North America, and cases continue to be detected almost every year in the Republic of Korea. CWD-infected animals contaminate the soil by releasing infectious prions through their excreta, and shed prions accumulate and remain infectious in the soil for years.

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Article Synopsis
  • African swine fever (ASF) is a deadly disease in pigs, and the first ASF virus isolate from Korea was used to study how the disease spreads through different infection routes.* -
  • In experiments, pigs were infected through intraoral, intranasal, and intramuscular methods, with all methods showing similar disease progression, whereas pigs exposed through direct contact showed comparable symptoms after a 7-day latency.* -
  • The severity of symptoms varied between infection routes, suggesting that the intramuscular route isn’t ideal for understanding ASF virus mechanisms, while intraoral and intranasal routes are better suited for vaccine and pathogenicity studies.*
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Prion diseases are fatal and malignant infectious encephalopathies induced by the pathogenic form of prion protein (PrP) originating from benign prion protein (PrP). A previous study reported that the M132L single nucleotide polymorphism (SNP) of the prion protein gene (PRNP) is associated with susceptibility to chronic wasting disease (CWD) in elk. However, a recent meta-analysis integrated previous studies that did not find an association between the M132L SNP and susceptibility to CWD.

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Synucleinopathies are characterized by the deposition of alpha-synuclein (α-syn) aggregates in brain tissue. Pathological α-syn aggregates propagate in a prion-like manner and display prion-like biochemical properties. Using RT-QuIC, we measured α-syn seeding activity from brains of Dementia with Lewy body (DLB) patients post autoclave.

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Article Synopsis
  • African swine fever (ASF) was first identified in South Korea in 2019, with reports of 21 domestic pig cases and 1,875 infected wild boars by the end of 2021.
  • Researchers experimented with four different ASF virus strains from domestic pigs between 2019 and 2021 to assess their virulence in pigs.
  • All infected pigs succumbed to the disease within 4-9 days, displaying severe clinical symptoms and necropsy findings, confirming that the virulence of the ASFV strains in South Korea remained consistently high during that time.
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  • Prion diseases, like chronic wasting disease (CWD), are fatal brain disorders caused by abnormal proteins derived from the normal prion protein gene (PRNP).
  • Researchers studied genetic variations (SNPs) in the PRNP gene of sika deer to determine if these variations contribute to CWD susceptibility, finding a significant association with the c.56G > A mutation.
  • Their analysis revealed 24 SNPs, including 22 new ones, with predictions that certain mutations could adversely affect the protein's function and structure, marking the first such study in sika deer.
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Chronic wasting disease (CWD) is a deleterious brain proteinopathy caused by a pathogenic form of prion protein (PrP), which is converted from a benign form of prion protein (PrP) encoded by the prion protein gene (). In elk, the M132L single nucleotide polymorphism (SNP) of the gene likely plays a pivotal role in susceptibility to CWD. However, the association of the M132L SNP with susceptibility to CWD has not been evaluated in Korean elk to date.

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Article Synopsis
  • Chronic wasting disease (CWD) is a prion disease affecting deer, linked to abnormal prion proteins, and previous studies suggest that prion genes may influence susceptibility to various prion diseases.
  • Researchers studied a total of 642 deer (elk, red deer, and sika deer) to analyze polymorphisms in the prion-related protein gene (PRNT) and found significant differences in genotype and allele frequencies between CWD-positive and CWD-negative red deer.
  • This study is the first to establish a strong association between certain PRNT SNPs and the susceptibility to CWD, particularly in red deer, while no such association was observed in elk or sika deer.
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Prion diseases are transmissible spongiform encephalopathies caused by deleterious prion protein (PrP ) derived from normal prion protein (PrP ), which is encoded by the prion protein gene (PRNP). We performed an in-depth examination to detect PrP by using enzyme immunoassay (EIA), real-time quaking-induced conversion reactions (RT-QuIC) and protein misfolding cyclic amplification (PMCA) in nine brain tissues derived from three Holstein cattle carrying the E211K somatic mutation of the bovine PRNP gene. The EIA, RT-QuIC and PMCA analyses were not able to detect the PrP band in any tested samples.

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(Erxleben, 1777) has been used as a model species of Chronic Wasting Disease (CWD). We completed the mitochondrial genome of , susceptible to the CWD. Its length is 16,428 bp, identical to the previous mitochondrial genome of , and 37 genes (13 protein-coding genes, two rRNAs, and 22 tRNAs) were identified.

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(Merriam, 1905) is one of the subspecies of elk distributed only in California, USA. We completed the first mitogenome of . Its length is 16,428 bp, which is in middle among 24 available mitogenomes.

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Chronic wasting disease (CWD) affects a broad array of cervid species and continues to be detected in an expanding geographic range. Initially introduced into the Republic of Korea through the importation of CWD-infected elk (), additional cases of CWD were subsequently detected in farmed Korean elk and sika deer (). Wild and farmed sika deer are found in many regions of Asia, North America, and Europe, although natural transmission to this species has not been detected outside of the Republic of Korea.

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Chronic wasting disease (CWD) is caused by abnormal deleterious prion protein (PrP), and transmissible spongiform encephalopathy occurs in the Cervidae family. In recent studies, the susceptibility of prion disease has been affected by polymorphisms of the prion gene family. However, the study of the prion-related protein gene (PRNT) is rare, and the DNA sequence of this gene was not fully reported in all Cervidae families.

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African swine fever, a fatal haemorrhagic disease of swine, was confirmed in domestic pigs for the first time in South Korea in September 2019. The causative virus belonged to the p72 genotype II and had an additional tandem repeat sequence in the intergenic region (IGR) between the I73R and I329L.

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Chronic wasting disease (CWD) agents are shed into biological samples, facilitating their horizontal transmission between cervid species. Once prions enter the environment, binding of PrP by soil particles may maintain them near the soil surface, posing a challenge for decontamination. A 2 N sodium hydroxide (NaOH) or 2% sodium hypochlorite (NaClO) solution is traditionally recommended for prion decontamination of equipment and surfaces.

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Conformational conversion of the normal cellular isoform of the prion protein PrP into an infectious isoform PrP causes pathogenesis in prion diseases. To date, numerous antiprion compounds have been developed to block this conversion and to detect the molecular mechanisms of prion inhibition using several computational studies. Thus far, no suitable drug has been identified for clinical use.

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Enzyme-linked immunosorbent assay (ELISA) performed using extensively purified bacterially expressed bovine prion protein (PrP) shows decreased cross-reactivity. We generated a transduced Madin-Darby bovine kidney (MDBK) cell line continuously expressing glycosylphosphatidylinositol (GPI)-anchorless bovine PrP (designated as MDBK ∆GPI protein) by using a lentiviral expression system. The present study also described the method for purifying bovine PrP through sequential culturing without the need for complex purification protocol.

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M2B cells with persistent classical bovine spongiform encephalopathy (C-BSE) have been established previously. In this study, we performed strain characterization of the M2B cell line in bovine PrP overexpressing mice (Tg 1896). Mice intracranially inoculated with M2B cells and C-BSE survived for 451 ± 7 and 465 ± 31 d post inoculation, respectively.

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Objective: To investigate whether bihemispheric anodal transcranial direct current stimulation (tDCS) with conventional dysphagia therapy could improve swallowing function in chronic stroke patients with dysphagia.

Design: Randomized controlled trial.

Subjects: Twenty-six patients with dysphagia for at least 6 months post-stroke were randomly assigned into: (i) bihemispheric anodal tDCS group; or (ii) sham group.

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Chronic wasting disease (CWD) is a naturally occurring prion disease in North American deer (Odocoileus species), Rocky mountain elk (Cervus elaphus nelsoni) and moose (Alces alces). The disease was first confirmed in the Republic of Korea in 2001, and subsequent cases were diagnosed in 2004, 2005 and 2010. The experimental host range of CWD includes ferrets, several species of voles, white-footed mice, deer mice and Syrian golden hamsters.

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An outbreak of foot-and-mouth disease caused by serotype O virus occurred in cattle and pigs in South Korea during November 2010-April 2011. The highest rates of case and virus detection were observed 44 days after the first case was detected. Detection rates declined rapidly after culling and completion of a national vaccination program.

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Chronic wasting disease (CWD) has been recognized as a naturally occurring prion disease in North American deer (Odocoileus species), Rocky Mountain elk (Cervus elaphus nelsoni) and moose (Alces alces). The disease was confirmed only in elk in the Republic of Korea in 2001, 2004 and 2005. Epidemiological investigations showed that CWD was introduced via importation of infected elk from Canada between 1994 and 1997.

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Elk prion protein (PrP(C)) has been confirmed to be capable of rendering rabbit epithelial RK13 cells permissive to temporal infection by chronic wasting disease (CWD) prions. The present study satisfactorily generated persistently CWD prion-affected RK13 cells (RKC1-11) using elk PrP(C) expressing cells (elkRK13) that were generated via the lentiviral expression system with high efficiency. The elkRK13 cells have been shown to be permissive to accumulation of abnormal isoforms of prion protein (PrP(Sc)) resulting from CWD prions up to 97 serial passages thus far.

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Background: Ocular motor dysfunction is common in patients with head trauma. Also, traumatic lateral gaze palsy is usually associated with brain stem lesion, peripheral nerve injury with or without basilar skull fracture and lateral rectus muscle injury or entrapment. However, isolated bilateral abducens nerve palsy is extremely rare.

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