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Dapagliflozin is a recently developed oral anti-diabetic drug and SGLT2 inhibitor with well-known cardioprotective and renoprotective effects. Although a reduction of the glomerular filtration rate is induced by volume depletion and tubule-glomerular feedback during the early period after administering a SGLT2 inhibitor, the renal prognosis improves more with a decrease of proteinuria. However, the risk of acute kidney injury increases in heart failure and hypovolemia patients, and in those taking certain drugs, such as non-steroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitor/angiotensin II receptor blockers, or diuretics. We report acute kidney injury after dapagliflozin administration in a diabetic patient with acute cerebral infarction accompanied by right hemiplegia, motor aphasia, and dysphagia. (Korean J Med 2020;95:404-408)

H5 and H7 subtypes of low pathogenic avian influenza viruses (LPAIVs) can mutate to highly pathogenic forms and are therefore subject to stringent controls. We characterized H5 LPAIVs isolated from wild-bird habitats and duck farms in South Korea from 2010 to 2017. Through nationwide active surveillance for AIVs, 59 H5 LPAIVs were isolated from wild-bird habitats (a mean annual rate of 5.3% of AIV isolations). In 2015, one LPAI H5N3 strain was isolated on a duck farm. Phylogenetic analysis revealed that the hemagglutinin (HA) gene of H5 isolates belonged to the Eurasian lineage, classified into three subgroups (HA-II, HA-III, and HA-IV). The H5 LPAIVs of the HA-III and HA-IV subgroups appeared in 2015 and 2017 in unusually high proportions (13.1% and 14.4%, respectively). In gene-constellation analysis, H5 LPAIVs isolated from 2015 to 2017 constituted ≥ 35 distinct genotypes, representing high levels of genetic diversity. Representative strains of three HA subgroups replicated restrictively in specific-pathogen-free chickens. Among the 11 isolates that were tested, 10 infected and replicated in mice without prior adaptation. The frequency of recent H5 LPAIV isolates with high genetic diversity indicates the importance of continued surveillance in both wild birds and poultry to monitor genetic and pathobiological changes.

Human infection by avian-origin subtype H10 influenza viruses has raised concerns about the pandemic potential of these microbes. H10 subtype low pathogenic avian influenza viruses (LPAIVs) have been isolated from wild birds and poultry worldwide. Here, we isolated 36 H10 LPAIVs from wild bird habitats (a mean annual rate of 3.8% of all avian influenza virus isolations) from January 2010 to April 2019 through a nationwide active surveillance program for avian influenza viruses (AIVs). Phylogenetic analysis revealed that the hemagglutinin (HA) gene of H10 isolates formed eight distinct genetic subgroups (HA-A-H). Unlike other Eurasian-origin subgroups, the HA-H subgroup belonged to the North American lineage. Gene-constellation analysis revealed that 24 H10 LPAIVs constituted ≥18 distinct genotypes, representing high levels of genetic diversity. An intravenous pathogenicity index (IVPI) experiment showed that the pathogenicity of representative strains of the HA-B, E, and G subgroups possessing an IVPI score > 1.2 was associated with replication capacity in the chicken kidney in the absence of trypsin. Intranasal inoculation experiments showed that a representative strain of the HA-D subgroup replicated and transmitted in chickens without clinical signs. Subclinical virus shedding in chickens may contribute to its silent spread among the poultry population. Moreover, six representative viruses replicated in the lungs of mice without prior adaptation and a representative strain of the HA-C subgroup caused 40% mortality, with severe body weight loss. These findings highlight the importance of intensive surveillance of wild bird habitats, poultry farms, and the animal-human interface, along with appropriate risk assessment of isolated viruses. This article is protected by copyright. All rights reserved.

During the 2020–2021 winter season, an outbreak of clade 2.3.4.4b H5N8 high pathogenicity avian influenza (HPAI) virus occurred in South Korea. Here, we evaluated the pathogenicity and transmissibility of A/mandarin duck/Korea/H242/2020 (H5N8) (H242/20(H5N8)) first isolated from this outbreak in specific pathogen-free (SPF) chickens and commercial ducks in comparison with those of A/duck/Korea/HD1/2017(H5N6) (HD1/17(H5N6)) from a previous HPAI outbreak in 2017–2018. In chickens, the 50% chicken lethal dose and mean death time of H242/20(H5N8) group were 104.5 EID50 and 4.3 days, respectively, which indicate less virulent than those of HD1/17(H5N6) (103.6 EID50 and 2.2 days). Whereas, chickens inoculated with H242/20(H5N8) survived longer and had a higher titer of viral shedding than those inoculated with HD1/17(H5N6), which may increase the risk of viral contamination on farms. All ducks infected with either HPAI virus survived without clinical symptoms. In addition, they exhibited a longer virus shedding period and a higher transmission rate, indicating that ducks may play an important role as a silent carrier of both HPAI viruses. These results suggest that the pathogenic characteristics of HPAI viruses in chickens and ducks need to be considered to effectively control HPAI outbreaks in the field.

Samples from 29 adult Gentoo (Pygoscelis papua), Chinstrap (Pygoscelis antarcticus), and Adélie Penguins (Pygoscelis adeliae) at the King Sejong Station on Nar̢ ebski Point, King George Island, Antarctica, were investigated to detect antibodies to avian influenza, Newcastle disease virus, infectious bursal disease virus, infectious bronchitis virus, Mycoplasma, and Salmonella. Antibodies were identified from one Gentoo Penguin and one Chinstrap Penguin against infectious bronchitis virus; from one Gentoo Penguin against Newcastle disease virus; from one Gentoo Penguin against Mycoplasma synoviae; and from two Chinstrap Penguins against Salmonella pullorum. Thirty-three dead penguin chicks were collected from the breeding colony for necropsy, histopathological examination, and polymerase chain reaction. Pulmonary hemorrhage and congestion were the main necropsy findings.

BackgroundStenotrophomonas maltophilia ( S. maltophilia) is a globally emerging, rare, waterborne, aerobic, gram-negative, multiple-drug-resistant organism, most commonly associated with respiratory tract infection in humans. Computed tomography (CT) findings in patients with S. maltophilia pneumonia are rarely reported.PurposeTo compare CT findings between immunocompromised and immunocompetent patients, and to determine characteristic imaging findings of S. maltophilia pneumonia.Material and MethodsCT findings of eight immunocompromised and 29 immunocompetent patients with proven S. maltophilia pneumonia were reviewed retrospectively. Different patterns of CT abnormalities between immunocompromised and immunocompetent patients were compared by Fisher’s exact test.ResultsPatchy ground-glass opacities (GGOs) were the most common CT findings, present in 36 (97.3%) of the 37 patients. Among the patients with patchy GGOs, consolidation was seen in 29 (78.4%) patients, and centrilobular nodules were noted in 15 (40.5%) patients. The transaxial distribution of the parenchymal abnormalities was predominantly randomly distributed in 30 (81.1%) cases. Regarding longitudinal plane involvement, the predominant zonal distributions were the diffuse distribution (n=23, 62.2%) and the lower lung zone (n=14, 37.8%). None of the patients showed upper lung zone predominance. The proportion of patients with parenchymal CT findings or associated findings in the immunocompromised patients was not significantly different from that of the immunocompetent patients. However, lower lung zone predominance on the longitudinal plane was significantly more common in immunocompetent patients than in immunocompromised patients (14/29 vs. 0/8, P=0.015). And diffuse distribution of parenchymal abnormalities on a longitudinal plane was significantly more frequent in immunocompromised patients than in immunocompetent patients (8/8 vs. 15/29, P=0.015).ConclusionThe most common CT patterns of S. maltophilia pneumonia in immunocompromised and immunocompetent patients were patchy GGOs and consolidation. However, in immunocompetent patients, parenchymal abnormalities were more predominately distributed in lower lung zone than in immunocompromised patients; and in immunocompromised patients, parenchymal abnormalities were more diffusely distributed than in immunocompetent patients.

Background To date, no genetic analysis of inherited retinal disease (IRD) using whole-exome sequencing (WES) has been conducted in a large-scale Korean cohort. The aim of this study was to characterise the genetic profile of IRD patients in Korea using WES. Methods We performed comprehensive molecular testing in 168 unrelated Korean IRD patients using WES. The potential pathogenicity of candidate variants was assessed using the American College of Medical Genetics and Genomics and the Association for Molecular Pathology variant interpretation guidelines, in silico prediction tools, published literature, and compatibility with known phenotypes or inheritance patterns. Results Causative variants were detected in 86/168 (51.2%) IRD patients, including 58/107 (54.2%) with retinitis pigmentosa, 7/15 (46.7%) with cone and cone-rod dystrophy, 2/3 (66.6%) with Usher syndrome, 1/2 (50.0%) with congenital stationary night blindness, 2/2 (100.0%) with Leber congenital amaurosis, 1/1 (100.0%) with Bietti crystalline dystrophy, 1/1 (100.0%) with Joubert syndrome, 9/10 (90.0%) with Stargardt macular dystrophy, 1/10 (10.0%) with vitelliform macular dystrophy, 1/11 (9.1%) with other forms of macular dystrophy, and 3/4 (75.0%) with choroideraemia. USH2A, ABCA4, and EYS were the most common causative genes associated with IRD. For retinitis pigmentosa, variants of USH2A and EYS were the most common causative gene mutations. Conclusions This study demonstrated the distribution of causative genetic mutations in Korean IRD patients. The data will serve as a reference for future genetic screening and development of treatment modalities for Korean IRD patients.

In December 2016, highly pathogenic avian influenza (HPAI) infection with systemic pathologic lesions was found in cats in South Korea. Genetic analyses indicated that the feline isolates were similar to HPAI H5N6 viruses isolated in chicken farms nearby. This finding highlights the need for monitoring of domestic mammals during HPAI outbreaks.

Avian influenza viruses (AIVs) are genetically separated by geographical barriers, resulting in the independent evolution of North American and Eurasian lineages. In the present study, to determine whether AIVs possessing the North American-origin nonstructural (NS) gene were previously introduced into South Korea, we performed a genetic analysis of AIVs isolated from fecal samples of migratory birds. We detected seven viruses possessing the North American-origin NS allele B among 413 AIV-positive samples obtained during AI surveillance between 2012 and 2017. We found evidence for the intercontinental transmission of at least three genetically distinct clusters of the B allele of the North American-origin NS gene into Eurasia at a low frequency. The host species of three viruses were identified as the greater white-fronted goose (Anser albifrons) using a DNA barcoding technique. Moreover, we used GPS-CDMA-based telemetry to determine the migration route of the greater white-fronted goose between the Far East of Russia and South Korea and found that this species may play an important role as an intermediate vector in the intercontinental transmission of AIVs. To improve our understanding of the role of wild birds in the ecology of AIVs, advanced AIV surveillance is required in the Far East of Russia as well as in Alaska region of Beringia accompanied by host identification and wild bird tracking.

Purpose The aim of this study was to investigate the efficacy and safety of a mixed extract of Trigonella foenum-graecum seed and Lespedeza cuneata (TFGL) for the treatment of testosterone deficiency syndrome (TDS). Materials and methods Patients were instructed to take a placebo or 200 mg TFGL capsule twice per day for 8 weeks. The primary efficacy variable was the change from baseline in the Aging Males' Symptoms scale (AMS), as well as levels of serum total and free testosterone. Secondary efficacy measurements included changes from baseline in the number of 'yes' answers on the Androgen Deficiency in the Aging Male (ADAM) questionnaire, levels of serum total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglyceride, all domain scores of the International Index of Erectile Function (IIEF), perceived stress scale-10 (PSS-10), as well as changes in body composition. Results The TFGL group exhibited a significant improvement in the AMS scores at 8 weeks, total testosterone at 8 weeks, and free testosterone at 4 and 8 weeks. At 4 weeks, 25% of the TFGL group changed to negative in terms of ADAM scores and 34.1% of the TFGL group had negative scores at the end of the study. The TFGL group exhibited a significant improvement in total cholesterol, HDL-C, LDL-C, triglyceride, IIEF scores, and PSS-10 scores at 8 weeks. Conclusions The mixed extract of TFGL resulted in significant improvements in symptoms of TDS, as measured by the AMS, ADAM, PSS-10 and testosterone levels.

Background/Aims: High-mobility group box 1 (HMGB1) elicits inflammatory responses through interactions with the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4). We investigated how RAGE and TLR4 expressions are regulated after HMGB1 stimulation in cultured human aortic endothelial cells (HAECs). Methods: RAGE and TLR4 expressions were analyzed by Western blot analysis and immunofluorescence staining. A disintegrin and metalloprotease 17 (ADAM17) activity was measured using a fluorogenic substrate. Results: Upon treatment with HMGB1, both RAGE and TLR4 began to decrease in cell lysate and remained decreased up to 24 h. The decrease in cellular RAGE and TLR4 was accompanied by an increase of N-terminal fragment of RAGE and TLR4 in culture supernatant, indicating ectodomain shedding of the receptors. HMGB1 activated p38 mitogen-activated protein kinase (p38 MAPK) and ADAM17, while HMGB1-induced ADAM17 activation was inhibited by SB203580, a p38 MAPK inhibitor. HMGB1-induced ectodomain shedding of RAGE and TLR4 was prevented by siRNA depletion of ADAM17 as well as TAPI-2, an inhibitor of ADAM family, and SB203580. HMGB1 pretreatment abolished p38 MAPK activation in response to 2nd HMGB1 stimulation. In the cells depleted of ADAM17, HMGB1-induced p38 MAPK activation was prolonged. siRNA depletion of RAGE, but not TLR4, suppressed HMGB1-induced p38 MAPK activation. Conclusion: In response to HMGB1 stimulation, HAECs rapidly undergo ectodomain shedding of RAGE and TLR4, and thereby become insensitive to further HMGB1 stimulation. ADAM17, activated through RAGE-p38 MAPK pathway, is implicated in the ectodomain cleavage of the receptors.

Zoonotic infection with avian influenza viruses (AIVs) of subtype H7, such as H7N9 and H7N4, has raised concerns worldwide. During the winter of 2020–2021, five novel H7 low pathogenic AIVs (LPAIVs) containing different neuraminidase (NA) subtypes, including two H7N3, an H7N8, and two H7N9, were detected in wild bird feces in South Korea. Complete genome sequencing and phylogenetic analysis showed that the novel H7Nx AIVs were reassortants containing two gene segments (hemagglutinin (HA) and matrix) that were related to the zoonotic Jiangsu–Cambodian H7 viruses causing zoonotic infection and six gene segments originating from LPAIVs circulating in migratory birds in Eurasia. A genomic constellation analysis demonstrated that all H7 isolates contained a mix of gene segments from different viruses, indicating that multiple reassortment occurred. The well-known mammalian adaptive substitution (E627K and D701N) in PB2 was not detected in any of these isolates. The detection of multiple reassortant H7Nx AIVs in wild birds highlights the need for intensive surveillance in both wild birds and poultry in Eurasia.

Background To report the successful treatment of ocular toxoplasmosis and present the use of multimodal imaging to describe the changes in ocular toxoplasmic lesions subsequent to treatment. Case presentation A 73-year-old female visited the clinic with decreased visual acuity in the left eye. Fundus examination showed severe vitreous haze with yellow-white infiltrates near the foveal center. Spectral-domain optical coherence tomography (SD-OCT) revealed disorganization of the retinal structure with markedly thickened choroid beneath the active lesion. Highly elevated serum titers of IgG antibodies against Toxoplasma gondii were observed. Topical and systemic steroids with oral Bactrim were administered after a diagnosis of ocular toxoplasmosis was made. After improvement in the severity of vitritis, structural en face swept-source optical coherence tomography (SS-OCT) imaging demonstrated diffuse choroidal dilation with many collateral vascular branches surrounding the active lesion. Eight intravitreal injections of clindamycin (1 mg/0.1 ml) were administered at 1- to 2-week intervals along with systemic antibiotics and steroids. After the treatment, the toxoplasmic lesion resolved to an atrophic chorioretinal scar. Dilated choroidal vessel size was normalized and collateral vascular branches were markedly constricted on structural en face SS-OCT images. Conclusions This is the first detailed report on the morphological changes in the choroidal vasculature surrounding ocular toxoplasmic lesions that were characterized using SS-OCT-A imaging. Multimodal imaging with SS-OCT-A can be valuable in clinical diagnosis as well as in clarifying the mechanism of choroidal structural changes in ocular toxoplasmosis.

INTRODUCTION AND OBJECTIVES:Despite the increasing availability of effective conventional medical treatments, plant-derived and herbomineral remedies continue to be a popular alternative for men se...

In 2016, novel H5N6 highly pathogenic avian influenza virus emerged in Korea. During the outbreak, the virus caused the largest culling, especially in brown chicken lines. We determined the pathogenicity and transmissibility of the virus in 2 white chicken lines of the specific pathogen-free chickens, broilers and brown chicken line of Korean native chicken (KNC). A KNC had a longer virus shedding period and longer mean death time than others. Our study showed that this characteristic in the KNC might have contributed to a farm-to-farm transmission of the brown chicken farms.

During October 2020–January 2021, we isolated a total of 67 highly pathogenic avian influenza (HPAI) H5N8 viruses from wild birds and outbreaks in poultry in South Korea. We sequenced the isolates and performed phylogenetic analysis of complete genome sequences to determine the origin, evolution, and spread patterns of these viruses. Phylogenetic analysis of the hemagglutinin (HA) gene showed that all the isolates belong to H5 clade 2.3.4.4 subgroup B (2.3.4.4b) and form two distinct genetic clusters, G1 and G2. The cluster G1 was closely related to the 2.3.4.4b H5N8 HPAI viruses detected in Europe in early 2020, while the cluster G2 had a close genetic relationship with the 2.3.4.4b H5N8 viruses that circulated in Europe in late 2020. A total of seven distinct genotypes were identified, including five novel reassortants carrying internal genes of low pathogenic avian influenza viruses. Our Bayesian discrete trait phylodynamic analysis between host types suggests that the viruses initially disseminated from migratory waterfowl to domestic duck farms in South Korea. Subsequently, domestic duck farms most likely contributed to the transmission of HPAI viruses to chicken and minor poultry farms, highlighting the need for enhanced, high levels of biosecurity measures at domestic duck farms to effectively prevent the introduction and spread of HPAI.

This study reports the findings from a mixed-methods evaluation of the effectiveness of a choral program for 34 homeless men with substance abuse and mental illnesses. The evaluation focused on the chorus experience as one way to promote community integration and recovery. Fifteen residents (44.1%) were chorus members (CMs), and their responses were compared with those of 19 nonmembers (NCMs). When examining the quantitative data only, significant differences were not found between CMs and NCMs. However, narrative data and participant observation revealed that the choral program may have helped CMs improve their subjective experience of community integration by enhancing psychosocial components.

Background: The objective of present study is to observe the anti-adipogenic effects of SlenestaTM (SLD), a standard potato protein extracts containing 5% potato protease inhibitor II (PI2) on the 3T3-L1 preadipocytes which are able to differentiate into mature adipocytes and accumulate lipids, as an obesity model with cytotoxicity and antioxidant effects. Materials and Methods: The cytotoxicity of SLD was observed against 3T3-L1 pre-adipocyte cell line by MTT assay, and also anti-adipogenic effects were observed through lipid accumulation assay during 3T3-L1 differentiation as comparing with N-Acetyl-L-cysteine (NAC). In addition, antioxidant effects of SLD were detected by free radical scavenging capacity and superoxide dismutase (SOD)-like activity as comparing with ascorbic acid. Results: SLD showed obvious cytotoxicity against 3T3-L1 pre-adipocyte cell line at higher concentrations, from 1.5 mg/ml for 72 hrs treatment, and cytotoxic IC50 of SLD after 24, 48 and 72 hrs treatment times were detected as 10.11 ± 0.67, 5.71 ± 0.37 and 5.34 ± 0.21 mg/ml, respectively. SLD concentration-dependently inhibited the lipid accumulations formatted during 3T3-L1 cell differentiations, and also effectively showed DPPH radical scavenging activity (IC50 = 161.98 ± 64.65 μg/ml) and SOD-like effects (IC50 = 284.54 ± 54.47 μg/ml). Conclusion: The results suggest that SLD effectively inhibited 3T3-L1 adipose cell differentiations may be through antioxidant activities and direct cytotoxicity in case of higher concentration, along with already known satiety effects mediated by increases of circulating cholecystokinin. These findings are considered as direct evidences that SLD may serve as a predictable functional ingredient for obesity as an alternative therapy.

We report the identification of novel highly pathogenic avian influenza viruses of subtype H5N6, clade 2.3.4.4, that presumably originated from China. In addition, reassortant strains with Eurasian lineage low pathogenic avian influenza viruses were isolated in wild birds and poultry in South Korea. The emergence of these novel H5N6 viruses and their circulation among bird populations are of great concern because of the potential for virus dissemination with intercontinental wild bird migration.

In this study, we characterized H7 subtype low-pathogenicity (LP) influenza A viruses (IAVs) isolated from wild bird habitats in the Republic of Korea from 2010 to early 2017. Through national surveillance, 104 H7 IAVs were isolated, accounting for an average of 14.9% of annual IAV isolations. In early 2017, H7 subtypes accounted for an unusually high prevalence (43.6%) of IAV detections in wild birds. Phylogenetic analysis revealed that all the viruses isolated in the winter of 2016–2017 fell within cluster II of group C, belonging to the Eurasian lineage of H7 IAVs. Notably, cluster II of group C included the H7 gene from the highly pathogenic H7N7 IAV that was detected in northeastern Italy in April of 2016. Through a gene-constellation analysis, the H7 LPIAVs that we isolated constituted ≥11 distinct genotypes. Because the viruses belonging to the genotypes G2.1 and G1 were observed most frequently, we compared the replication and transmission of representative viruses to these genotypes in specific-pathogen-free chickens. Notably, the representative G2.1 strain was capable of systemic replication and efficient transmission in chickens (as evidenced by virus isolation and histopathological examination) without any clinical signs except mortality (in one infected chicken). The efficient subclinical viral replication and shedding of the G2.1 virus in chickens may facilitate its silent spread among poultry after introduction. Given that wild birds harbor novel strains that could affect poultry, our results highlight the need for enhanced IAV surveillance in both wild birds and poultry in Eurasia.

H5Nx clade 2.3.4.4 highly pathogenic avian influenza viruses (HPAIVs) have been disseminated to wide geographic regions since 2014. In 2016, five distinct genotypes (C-1 to C-5) of clade 2.3.4.4c H5N6 HPAIVs were detected in South Korea. In this study, we evaluated the pathogenicity, susceptibility to infection, and transmissibility of the two strains representing the C-1 and C-4 genotypes of the H5N6 viruses, which have different PA and NS gene, in domestic ducks. Although the susceptibility to infection of domestic ducks to the two strains was similar, the C-4 genotype virus induced higher mortality in ducks than C-1 genotype virus. A higher titer of viral shedding were detected in ducks challenged with the C-4 genotype virus compared with the C-1 genotype virus. These results indicated that the reassortment of HPAIVs with prevailing low pathogenic avian influenza viruses could effect on the pathogenicity in ducks.

Novel H5N6 highly pathogenic avian influenza viruses (HPAIVs) were isolated from duck farms and migratory bird habitats in South Korea in November to December 2017. Genetic analysis demonstrated that at least two genotypes of H5N6 were generated through reassortment between clade 2.3.4.4 H5N8 HPAIVs and Eurasian low pathogenic avian influenza virus in migratory birds in late 2017, suggesting frequent reassortment of clade 2.3.4.4 H5 HPAIVs and highlighting the need for systematic surveillance in Eurasian breeding grounds.

Allogeneic natural killer (NK) cell therapy is a potential therapeutic approach for a variety of solid tumors. We established an expansion method for large-scale production of highly purified and functionally active NK cells, as well as a freezing medium for the expanded NK cells. In the present study, we assessed the effect of cryopreservation on the expanded NK cells in regards to viability, phenotype, and anti-tumor activity. NK cells were enormously expanded (about 15,000-fold expansion) with high viability and purity by stimulating CD3+ T cell-depleted peripheral blood mononuclear cells (PBMCs) with irradiated autologous PBMCs in the presence of IL-2 and OKT3 for 3 weeks. Cell viability was slightly reduced after freezing and thawing, but cytotoxicity and cytokine secretion were not significantly different. In a xenograft mouse model of hepatocellular carcinoma cells, cryopreserved NK cells had slightly lower anti-tumor efficacy than freshly expanded NK cells, but this was overcome by a 2-fold increased dose of cryopreserved NK cells. In vivo antibody-dependent cell cytotoxicity (ADCC) activity of cryopreserved NK cells was also demonstrated in a SCID mouse model injected with Raji cells with rituximab co-administration. Therefore, we demonstrated that expanded/frozen NK cells maintain viability, phenotype, and anti-tumor activity immediately after thawing, indicating that expanded/frozen NK cells can provide 'ready-to-use' cell therapy for cancer patients.

Dear Editor,Highly pathogenic avian influenza (HPAI) viruses of the H5 subtype remain a serious concern for both poultry and human health. The clade 2.3.4.4 H5 viruses have evolved into four geneti...

Plants rich in antioxidant substances may be useful for preventing skin aging. Pomegranates, containing flavonoids and other polyphenolic compounds, are widely consumed due to their beneficial properties. We examined the underlying mechanisms of dried pomegranate concentrate powder (PCP) on melanin synthesis in B16F10 melanoma cells. The antioxidant effects of PCP were determined by measuring free radical scavenging capacity and transcript levels of antioxidant enzymes. To explore the inhibitory effects of PCP on melanin synthesis, we measured tyrosinase activity and melanin content in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. In addition, the levels of tyrosinase-related protein-1 (TRP-1), TRP-2, tyrosinase, and microphthalmia-associated transcription factor (MITF) expression were determined by Western blotting. Changes in the phosphorylation status of protein kinase A (PKA), cAMP response element-binding protein (CREB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase (PI3K), serine/threonine kinase Akt, and glycogen kinase 3β (GSK3β) were also examined. The free radical scavenging activity of PCP increased in a dose-dependent manner. In PCP-treated B16F10 cells, transcript levels of glutathione peroxidase-1 (GPx-1) were increased compared with α-MSH-stimulated cells. In addition, PCP led to the down-regulation of phospho-p38, phospho-PKA, phospho-CREB, phospho-GSK3β, MITF, and TRP-1 compared with α-MSH-stimulated B16F10 cells. We believe this effect may be associated with PCP activity, which leads to the inhibition of melanin production and tyrosinase activity. These results suggest that PCP decreases tyrosinase activity and melanin production via inactivation of the p38 and PKA signaling pathways, and subsequently decreases phosphorylation of CREB, MITF, and melanogenic enzymes. These observations provided new insights on the molecular mechanisms of the skin-whitening property of PCP.

Susceptibility to infection varies by species, and asymptomatic birds could be carriers., In January 2014, an outbreak of infection with highly pathogenic avian influenza (HPAI) A(H5N8) virus began on a duck farm in South Korea and spread to other poultry farms nearby. During this outbreak, many sick or dead wild birds were found around habitats frequented by migratory birds. To determine the causes of death, we examined 771 wild bird carcasses and identified HPAI A(H5N8) virus in 167. Gross and histologic lesions were observed in pancreas, lung, brain, and kidney of Baikal teals, bean geese, and whooper swans but not mallard ducks. Such lesions are consistent with lethal HPAI A(H5N8) virus infection. However, some HPAI-positive birds had died of gunshot wounds, peritonitis, or agrochemical poisoning rather than virus infection. These findings suggest that susceptibility to HPAI A(H5N8) virus varies among species of migratory birds and that asymptomatic migratory birds could be carriers of this virus.

Inoculated wild ducks showed few symptoms but transmitted H5N8 viruses to other ducks., An outbreak of highly pathogenic avian influenza, caused by a novel reassortant influenza A (H5N8) virus, occurred among poultry and wild birds in South Korea in 2014. The aim of this study was to evaluate the pathogenesis in and mode of transmission of this virus among domestic and wild ducks. Three of the viruses had similar pathogenicity among infected domestic ducks: the H5N8 viruses were moderately pathogenic (0%–20% mortality rate); in wild mallard ducks, the H5N8 and H5N1 viruses did not cause severe illness or death; viral replication and shedding were greater in H5N8-infected mallards than in H5N1-infected mallards. Identification of H5N8 viruses in birds exposed to infected domestic ducks and mallards indicated that the viruses could spread by contact. We propose active surveillance to support prevention of the spread of this virus among wild birds and poultry, especially domestic ducks.

Idiopathic hypereosinophilia (IHE)/idiopathic hypereosinophilic syndrome (IHES) has been defined by a persistent elevation of the blood eosinophil count exceeding 1.5×103/μL, without evidence of reactive or clonal causes. While T-cell clonality assessment has been recommended for unexplained hypereosinophilia, this approach is not often applied to routine practice in the clinic. We hypothesized that the clonality would exist in a subset of IHE/IHES patients. We aimed to investigate the candidate mutations and T-cell clonality in IHE/IHES and to explore the role of mutations in eosinophil proliferation. We performed targeted capture sequencing for 88 genes using next-generation sequencing, T-cell receptor (TCR) gene rearrangement assays, and pathway network analysis in relation to eosinophil proliferation. By targeted sequencing, 140 variants in 59 genes were identified. Sixteen out of 30 patients (53.3%) harbored at least one candidate mutation. The most frequently affected genes were NOTCH1 (26.7%), SCRIB and STAG2 (16.7%), and SH2B3 (13.3%). Network analysis revealed that our 21 candidate genes (BIRC3, BRD4, CSF3R, DNMT3A, EGR2, EZH2, FAT4, FLT3, GATA2, IKZF, JAK2, MAPK1, MPL, NF1, NOTCH1, PTEN, RB1, RUNX1, TET2, TP53 and WT1) are functionally linked to the eosinophilopoietic pathway. Among the 21 candidate genes, five genes (MAPK1, RUNX1, GATA2, NOTCH1 and TP53) with the highest number of linkages were considered major genes. A TCR assay revealed that four patients (13.3%) had a clonal TCR rearrangement. NOTCH1 was the most frequently mutated gene and was shown to be a common node for eosinophilopoiesis in our network analysis, while the possibility of hidden T cell malignancy was indwelling in the presence of NOTCH1 mutation, though not revealed by aberrant T cell study. Collectively, these results provide new evidence that mutations affecting eosinophilopoiesis underlie a subset of IHE/IHES, and the candidate genes are inferred to act their potential roles in the eosinophilopoietic pathway.

Clade 2.3.4.4 H5N8 highly pathogenic avian influenza viruses (HPAIVs) have spread worldwide. Phylogenetic analysis identified two genetic groups of the H5N8 HPAIVs in South Korea; group A evolved further into four subgroups. Here, we examined the zoonotic potential, both in vivo and in vitro, of genetically distinct subgroups of H5N8 HPAIVs isolated in South Korea. When compared with other subgroups, A/mallard/Korea/H2102/2015 (H2102) virus caused relatively severe disease in mice at high doses. In ferrets, all H5N8 viruses replicated restrictively in the respiratory tract and did not induce significant clinical signs of influenza infection. In vitro studies, all viruses displayed a hemagglutinin phenotype that was poorly adapted for infection of mammals, although the H2102 virus exhibited higher replication kinetics at 33 °C than the others. Although H5N8 HPAIVs have not yet acquired all the characteristics required for adaptation to mammals, their ability to evolve continuously underscores the need for timely risk assessment.

This study examined the potential for cross-species transmission of influenza viruses by comparing the genetic and pathogenic characteristics of H1 avian influenza viruses (AIVs) with different host origins in Korea. Antigenic and phylogenetic analyses of H1 AIVs circulating in Korea provided evidence of genetic similarity between viruses that infect domestic ducks and those that infect wild birds, although there was no relationship between avian and swine viruses. However, there were some relationships between swine and human viral genes. The replication and pathogenicity of the H1 viruses was assessed in chickens, domestic ducks and mice. Viral shedding in chickens was relatively high. Virus was recovered from both oropharyngeal and cloacal swabs up to 5–10 days post-inoculation. The titres of domestic duck viruses in chickens were much higher than those of wild-bird viruses. Both domestic duck and wild-bird viruses replicated poorly in domestic ducks. None of the swine viruses replicated in chickens or domestic ducks; however, six viruses showed relatively high titres in mice, regardless of host origin, and induced clinical signs such as ruffled fur, squatting and weight loss. Thus, although the phylogenetic and antigenic analyses showed no evidence of interspecies transmission between birds and swine, the results suggest that Korean H1 viruses have the potential to cause disease in mammals. Therefore, we should intensify continuous monitoring of avian H1 viruses in mammals and seek to prevent interspecies transmission.

A 53-year-old woman presented with complaints of blurred vision in the left eye. She had been treated for recurrent non-functioning pituitary adenoma (NFPA). A vitreous biopsy followed by histopathologic examination showed the presence of Candida albicans. Meanwhile, Cushing׳s disease was diagnosed and gamma knife surgery was performed. Vitrectomy and antifungal treatment improved ocular infection and inflammation. Herein, we describe the first case of C. albicans endophthalmitis in a patient with NFPA evolving into Cushing׳s disease.

Pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, are pivotal for the development of inflammatory bowel disease (IBD), and down-regulation of the cytokines and cytokine-induced inflammatory responses therefore constitute pharmacological targets for the development of therapeutic strategies in IBD. In the current study, we found that 7-O-succinyl macrolactin A (SMA), a macrolide, potently inhibited TNF-α-induced adhesion of monocytes to colonic epithelial cells in a concentration-dependent manner, similar to rapamycin, a mTOR inhibitor. In addition, oral administration of SMA resulted in a significant suppression of clinical signs of TNBS-induced rat colitis, including weight loss, colon tissue edema, and myeloperoxidase activity, a marker for inflammatory cell infiltration, as well as microscopic damage score in a histomorphological examination of HE-stained colon tissue. More importantly, SMA was more efficacious in inhibition of intestinal inflammation than 5-aminosalicylic acid (5-ASA), an active metabolite of sulfasalazine, the most commonly prescribed agent for the treatment of IBD. Such anti-inflammatory activity showed correlation with significant suppression of adhesion molecules (ICAM-1 and VCAM-1), T-helper 1-type cytokines (TNF-α, IL-6), and chemokines (MCP-1, IL-8). In addition to inhibition of NF-κB nuclear translocation, SMA also caused significant suppression of TNF-α-induced phosphorylation of PI3K, Akt, mTOR and p70S6 kinase, similar to the effect of rapamycin, an immunosuppressant macrolide. Taken together, the current results suggest that managing both mTOR and NF-κB activation pathways using SMA may be a good therapeutic intervention for the treatment of IBD.

To the Editor: Highly pathogenic avian influenza (HPAI) viruses have caused considerable economic losses to the poultry industry and poses potential threats to animal and human health (www.oie.int/en/ and www.who.int/en/). Since 2003, influenza A(H5N1) viruses with a hemagglutinin (HA) gene derived from A/goose/Guandong/1/96–like viruses have become endemic to 6 countries (Bangladesh, China, Egypt, India, Indonesia, and Vietnam) (1) (www.cdc.gov/). Furthermore, HPAI viruses with an H5 subtype continue to undergo substantial evolution because of extensive genetic divergence and reassortment between other subtypes of influenza viruses. Especially in China, novel subtypes of H5 HPAI virus, such as influenza A(H5N2), influenza A(H5N5), and influenza A(H5N8) viruses, were reported during 2009–2011 (2,3).

BACKGROUND Some guidelines recommend a liver biopsy to all anti-hepatitis C virus (HCV) antibody-positive kidney transplant (KT) recipients. However, in the case of HCV RNA-negative KT recipients, the benefit of a liver biopsy is unclear. We examined the usefulness of a liver biopsy for anti-HCV antibody-positive and HCV RNA-negative patients by analyzing the hepatic histologic findings and clinical outcomes. METHODS A total of 30 anti-HCV antibody-positive patients who underwent liver biopsy before KT at Asan Medical Center were retrospectively recruited. The patients were divided into two groups based on HCV RNA positivity: 17 patients were positive and 13 patients were negative. Histologic evidence of hepatic inflammation and fibrosis was assessed using the METAVIR score, and clinical outcomes, including mortality, graft loss, and progression of liver disease, were compared. RESULTS The mean histologic activity scores for inflammation and fibrosis for the HCV RNA-positive and HCV RNA-negative groups were significantly different (inflammation score 1.11 ± 0.85 vs. 0.46 ± 0.51; P=0.01 and fibrosis score 1.05 ± 1.24 vs. 0.15 ± 0.37; P=0.01, respectively). The overall rates of mortality and graft loss were not significantly different between the two groups. Progression of liver disease was noted in the HCV RNA-positive group only. CONCLUSION The HCV RNA-negative group showed no evidence of liver disease progression. Neither did they show any histologic evidence of liver inflammation and fibrosis before KT. Therefore, it appears that liver biopsy is not necessary in anti-HCV antibody-positive and HCV RNA-negative KT recipients.

Background National surveillance of avian influenza virus (AIV) in South Korea has been annually conducted for the early detection of AIV and responses to the introduction of highly pathogenic avian influenza (HPAI) virus. In this study, we report on a nationwide surveillance study of AIV in domestic poultry and wild birds in South Korea between 2012 and 2014. Methods During the surveillance programs between 2012 and 2014, 141,560 samples were collected. Of these, 102,199 were from poultry farms, 8215 were from LBMs, and 31,146 were from wild bird habitats. The virus isolation was performed by inoculation of embryonated chicken eggs and AIV isolates were detected using hemagglutination assay. For subtying of AIV, the hemagglutinin and neuraminidase genes were confirmed by sequencing. Phylogenetic analysis of the H5 subtypes was performed using 28 H5 AIV isolates. Results Between 2012 and 2014, a total of 819 AIV were isolated from 141,560 samples. Virus isolation rates for AIV were 0.6, 0.4, 0.1, and 2.7% in wild birds (n = 202), domestic ducks (n = 387), minor poultry (n = 11), and the live bird market (LBM) (n = 219), respectively. In wild birds, various subtypes were found including H1–H7 and H9–H13. The major subtypes were H5 (n = 48, 23.9%: N3 (n = 4) and N8 (n = 44)), H4 (n = 39, 19.4%), and H1 (n = 29, 14.4%). In domestic poultry, mainly ducks, the H5N8 (n = 275, 59.3%), H3 (n = 30, 17.2%), and H6 (n = 53, 11.4%) subtypes were predominantly found. The most frequently detected subtypes in LBM, primarily Korean native chicken, were H9 (n = 169, 77.2%). H3 (n = 10, 4%) and H6 (n = 30, 13.7%) were also isolated in LBM. Overall, the prevalence of AIV was found to be higher between winter and spring and in western parts of South Korea. The unusual high prevalence of the H5 subtype of AIV was due to the large scale outbreak of H5N8 HPAI in wild birds and domestic poultry in 2014. Conclusions Enhanced surveillance and application of effective control measures in wild birds and domestic poultry, including LBM, should be implemented to control AI and eradicate HPAI. Electronic supplementary material The online version of this article (doi:10.1186/s12985-017-0711-y) contains supplementary material, which is available to authorized users.

A highly pathogenic avian influenza (HPAI) H5N8 virus was first detected in poultry and wild birds in South Korea in January 2014. Here, we determined the pathogenicity and transmissibility of three different clades of H5 viruses in mandarin ducks to examine the potential for wild bird infection. H5N8 (clade 2.3.4.4) replicated more efficiently in the upper and lower respiratory tract of mandarin ducks than two previously identified H5N1 virus clades (clades 2.2 and 2.3.2.1). However, none of the mandarin ducks infected with H5N8 and H5N1 viruses showed severe clinical signs or mortality, and gross lesions were only observed in a few tissues. Viral replication and shedding were greater in H5N8-infected ducks than in H5N1-infected ducks. Recovery of all viruses from control duck in contact with infected ducks indicated that the highly pathogenic H5 viruses spread horizontally through contact. Taken together, these results suggest that H5N8 viruses spread efficiently in mandarin ducks. Further studies of pathogenicity in wild birds are required to examine possible long-distance dissemination via migration routes.

Background: Endoplasmic reticulum (ER) stress induced by urinary albumin plays an important role in tubulointerstitial injury. We have shown that albumin-induced ER stress is regulated through reactive oxygen species (ROS)-c-Src kinase-mTOR signaling pathways. We postulated that peroxisome proliferator-activated receptor-γ (PPAR-γ) might also act as an upstream signaling molecule between c-Src kinase and mTOR. It has been suggested that AMP-activated protein kinase (AMPK) is involved in attenuation of ER stress. We examined whether and how activation of AMPK suppressed the albumin-induced ER stress and apoptosis in tubular epithelial cells. Method: HK-2 cells, a proximal tubular cell line, were used. Protein expressions were measured by Western blot analysis. Intracellular ROS and apoptosis were analyzed by flow cytometry. Results: Albumin-induced PPAR-γ expression and PPAR-γ inhibitor (GW9662) suppressed the albumin-induced ER stress. c-Src kinase inhibitor and GW9662 reduced the albumin-induced PPAR-γ and mTOR, respectively. Metformin (the best known clinical activator of AMPK) and another AMPK activator (AICAR) suppressed the albumin-induced ER stress via inhibition of ROS through induction of endogenous antioxidant thioredoxin. AMPK inhibitor blocked the effect of metformin and AICAR. Our in vivo animal study showed that metformin reduced the renal cortical expression of ER stress protein (GRP78) in protein-overload proteinuria rats. Metformin also reduced the caspase 3-dependent apoptosis induced by albumin. Conclusion: PPAR-γ was involved in albumin-induced ER stress as an upstream signaling molecule between c-Src kinase and mTOR. AMPK activation might be beneficial in attenuating the tubulointerstitial injury induced by albumin.

SUMMARY. A Newcastle disease surveillance program was conducted at live bird markets in Korea to expand our epidemiologic understanding of the disease in Korea. During the surveillance program, 10 lentogenic Newcastle disease viruses (NDVs) were isolated and identified from apparently healthy chickens and ducks at live bird markets. The lentogenic viruses had sequence motifs of either 112GKQGRL117 (n = 8) or 112GRQGRL117 (n = 2) at the F0 cleavage site. Sequencing and phylogenetic analyses of NDV isolates based on the hypervariable region of the F protein revealed two different genotypes: genotypes I (n = 8) and II (n = 2). Genotype I viruses were most closely related to the NDV V4 strain (n = 7) or the NDV Ulster 2C strain (n = 1). In contrast, genotype II viruses clustered with the NDV vaccine strains (LaSota and VG/GA) that are commonly used as live vaccines in Korea. The epidemiologic importance of NDV at live bird markets in Korea is discussed.

The cell-cycle regulator Cks1 has recently been implicated in Skp2-mediated ubiquitination of the tumor suppressor protein p27. In this article, we report that Cks1 exerts a Skp2-independent regulation of NF-κB that promotes interleukin-8 (IL-8) expression, which is critical to hepatocellular carcinoma (HCC) growth. Cks1 was upregulated frequently in human HCC tissues and cell lines. Cks1 knockdown in HCC cells elevated p27 levels and decreased tumorigenicity in a manner that was also associated with a strong downregulation of IL-8 expression. IL-8 downregulation was not phenocopied by either RNAi-mediated knockdown of Skp2 or ectopic overexpression of p27. However, attenuation of IL-8 expression itself was sufficient to blunt HCC growth. Mechanistic investigations revealed that IL-8 was controlled at a transcriptional level by Cks1 targeting of the NF-κB regulator IκBα, which led to NF-κB activation and IL-8 expression, through a p27-independent regulation of IκB kinase complex components. Collectively, our findings support the hypothesis that Cks1 supports hepatocarcinogenesis by NF-κB–mediated regulation of IL-8 expression, broadening the function of Cks1 in cancer beyond its role as a Skp2 cofactor in p27 ubiquitination. Cancer Res; 71(21); 6827–35. ©2011 AACR.

College of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, KoreaABSTRACT A 5-month (May to November in 2009) monitoring program for five viral pathogens in litter, such as avian influenza virus A (AIV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), fowl adenovirus (FAdV), and chicken infectious anemia virus (CIAV) was conducted in 62 flocks at 31 broiler farms (two flocks in each farm) in Korea in 2009. Viral pathogens were examined twice (before and at the end of the rearing period) at 31 broiler farms, and included fresh litter (n=16) and recycled litter (n=15) farms. Thirty-seven viruses (14 IBVs, 2 IBDVs, 9 FAdVs, and 12 CIAVs) were isolated from 75% (12/16) and 73% (11/15) of fresh litter and reused litter farms during the period, respectively, indicating no difference in viral contamination rate between farms using new and reused litter. Of these isolates, three (two CIAVs and one IBDV) were isolated from recycled litter samples collected before the rearing period at three broiler farms, whereas the others (n=34) were isolated from fresh and recycled litter samples collected at the end of the rearing period. When the performances, involving viability, body weight, and feed conversion ratio, were compared, no significant differences were found between farms using fresh and recycled litter during the period.(Key words : broiler, litter, production index, viral pathogen)

The outbreak of Newcastle disease occurred for the first time at a commercial chicken farm near Ulaanbaatar, Mongolia in August 2010. Newcastle disease virus (NDV) obtained from infected chickens in Mongolia was characterized by biological and molecular biological approches. Mongolian NDV isolate killed all of chicken embryos within 60 h in the mean death time assay, indicating virulent for chicken. A genomic region of 695 nts between nts 1055 of the M gene and 508 of the F gene was amplified by RT-PCR and sequenced. The deduced amino acid sequence of the F protein cleavage site was 112 RRQKRF 117 , which is a typical sequence of velogenic strains of NDV and is agreement with the result of the MDT assay. The sequence of the partial F gene (nts 47 to 435) was used for genotyping by phylogenetic analysis. The phylo- genetic analysis showed that the Mongolian isolate was of genotype VII within class of NDV. Further phylogenetic analysis on the genotype VII strains revealed that the isolates placed in a genetic sublineage of VIId and most closely related with velogenic strains of NDV circulating in Far-east Asian region especially China, suggesting the introduction of velogenic NDV into Mongolia from neighboring countries.

We conducted a 10-month (March to October 2009) surveillance of Newcastle disease virus (NDV) in 13 slaughter- houses in Korea. NDV was isolated in 13.0%, 13.3%, 16.0%, and 10.8% of chicken farms, transport vehicles, hang rooms, and chilling water, respectively. Of NDV isolates from slaughterhouses, 37% were isolated in July. All NDV isolates were determined to be lentogenic viruses by RT-PCR-based pathotyping, and all NDV isolates had the 112 GKQGR/L 117 motif at the cleavage site of the F protein. Phylogenetic analysis based on the hypervariable region of the F protein gene classified all 25 NDV isolates examined into genotype I within class . Of these, 24 were clustered together with the NDV V4 strain, while the remaining isolate was placed in the cluster belonging to the NDV Ulster 2C strain. Our results indicate that lentogenic NDV was a high-frequency contaminant in the serial process of ranging live birds to slaughtering at slaughterhouses.

Compounds containing 2-arybenzimidazole ring systems linked to arylpiperidines were synthesized and evaluated as MCH-R1 antagonists. The results of structure–activity relationship studies led to the identification of compound 4c as a potent MCH-R1 antagonist (IC50 = 1 nM). This compound also has good metabolic stability, and favorable pharmacokinetic and brain penetration properties. However 4c was found to be potent inhibitor of the hERG potassium channel.

Background: The phospholipase A2 receptor (PLA2R) is a major antigen found in patients with idiopathic membranous nephropathy (MN). The relationship of genetic polymorphisms of PLA2R with the susceptibility and clinical outcomes of this disease is unknown. Methods: We studied 199 patients with idiopathic MN followed up for 3.7 ± 3.2 years. We enrolled 33 patients with secondary MN and 356 subjects with normal blood pressure and no proteinuria. PLA2R single nucleotide polymorphisms (SNPs) were genotyped. Results: The allele frequencies of C in rs35771982 and G in rs3828323 were 73.6 and 73.9%, respectively. Subjects with the CC genotype in rs35771982 had a higher susceptibility to idiopathic MN compared to subjects with other genotypes (odds ratio 2.6; 95% confidence interval 1.8–4.0). Patients with secondary MN were not different from controls with regard to PLA2R genotype. No impact of genetic polymorphisms on renal survival was detected. Conclusion: The findings of this study suggest that PLA2R SNPs might be associated with the risk of developing MN.

An immunochromatograhy (IC) based infectious bursal disease virus (IBDV) detection kit, which employed two anti-IBDV VP2 monoclonal antibodies, was evaluated for rapid diagnosis of infectious bursal disease virus (IBD). The detection limit of the IC kit for IBDV was 10 3.1 to 10 3.9 EID??/mL, indicating that the IC kit detected IBDV sensitively as same as double antigen capture ELISA but less than a RT-PCR assay. The IC kit did not detect other viral pathogens such as Newcastle disease virus, infectious bronchitis, avian influenza virus, and infectious larynotracheitis virus. When applied to tissue samples of experimental chickens died 3 or 4 days post infection after very virulent IBDV (strain Kr/D62) infection, the IC kit detected IBDV in all samples of the bursa of Fabricius, spleen, kidney, cecal tonsil and in 87.5%, 37.5% and 0% of liver, thymus and proventriculus samples. In particular, BF tissue samples showed stronger signal bands than other tissues. Positive signal was observed. All except for one thymus sample of samples having negative results by the IC kit showed the same result with DAS-ELISA but RT-PCR assay detected IBDV in some of IC kit negative samples of thymus and proventriculus. When swab samples from the bursa of Fabricius of dead chickens (n=231) on field farms were tested, the sensitivity and specificity of the IC assay relative to RT-PCR was 100% (109/109) and 97.5% (119/122), respectively and kappa value between both assay was 0.97. The kit can provide a useful aid for rapid detection of IBDV in chickens under field circumstances.

We conducted a molecular epizootiological study of infectious bursal disease (IBD) in Korea by analyzing 85 IBD viruses (IBDVs) obtained from vaccinated or unvaccinated flocks between 1980 and 2007. Phylogenetic analysis of the partial nucleotide sequence of the hypervariable region of the VP2 gene (nucleotides 661-1020) and pathogenicity tests revealed more genetic and phenotypic diversity of IBDV in Korea than has been reported previously. We showed that very virulent IBDVs (vvIBDVs) were already present in Korea in 1986. Moreover, vvIBDVs were repeatedly detected in Korean poultry that had been vaccinated, which casts doubt on the IBD vaccine programs. We also identified novel putative antigenic variant (AV)-like IBDV isolates on the basis of their antigenic indices and the presence of amino acid changes (P222S or P222T-A321D) that are known to affect the antigenicity of VP2. These observations suggest that future studies examining the efficacy of conventional vaccines against atrophy of the bursa of Fabricius and vvIBDV shedding may be useful. Moreover, it will be of interest to determine the prevalence of putative Korean antigenic variants and whether these strains exert immunosuppressive effects in vaccinated birds.

To expand the epidemiological understanding of Newcastle disease virus (NDV) found in domestic ducks in Korea, 14 NDV isolates from apparently healthy domestic ducks were biologically and genetically characterized. Thirteen and 1 isolates of NDV were categorized into lentogenic and velogenic viruses, respectively, based on in vivo pathogenicity tests. Twelve lentogenic viruses showed HA activity to horse RBCs, while 1 lentogenic virus and the velogenic virus were negative. Lentogenic viruses (n=13) had sequence motifs of (112)ERQERL(117) (n=1) or (112)GRQGRL(117) (n=12) at the F0 cleavage site, while the velogenic virus (n=1) had a sequence motif of (112)RRQKRF(117) at the same site. Phylogenetic analysis revealed that at least three distinct genotypes may exist in domestic ducks in Korea; one class I genotype (genotype 2), and two class II (genotypes I and VII) genotypes. The class I virus was most closely related to strains of genotype 2 which were isolated in birds from the USA, Germany and Denmark. Twelve lentogenic class II viruses were grouped together in genotype I, and were then divided into at least three clusters, namely Aomori-like, Ulster2C-like, and V4-like. The velogenic class II virus was assigned to genotype VII which represents viruses responsible for recent epidemics in many Asian countries including Korea. The epidemiological importance of domestic duck isolates of NDV in Korea is discussed.

Avian paramyxovirus (APMV) consists of nine serotypes, APMV-1 through -9, of which only APMV-1 and APMV-6 have been fully sequenced. Here, we present the complete 15,054 nt RNA genome of APMV-4 isolated from a mallard duck, which conformed to the "rule of six." The APMV-4 genome had six transcriptional units in the order 3'-NP-P/V-M-F-HN-L-5', which coded for the nucleocapsid (N), phospho- (P), matrix (M), fusion (F), hemagglutinin-neuraminidase (HN), and large (L) proteins. Similar to APMV-1 but unlike APMV-6, APMV-4 lacked a small hydrophobic protein. The leader and trailer sequences were 55 and 17 nt in length, respectively, and the 12 nt-terminal regions of both ends of the APMV-4 genome were complementary. Using phylogenetic analysis, APMV-4 was classified as a member of the genus Avulavirus, and was more closely related to APMV-1 than to APMV-2 or APMV-6. These results may help establish the taxonomic position of Paramyxoviridae, Avulavirus members.

We thank Hyuk-Man Kwon, Eun-Im Yun, Kyeong-Hwa Han, Hee-Kyung Jang, and Won-Joung Kim for excellent technical assistance. We also thank the Animal Disease Control Division and the Veterinary Epidemiology Division of NVRQS for their efforts to control HPAI. This work was supported by grant no. RO1-2005-000- 10585-0 from the Basic Research Program of the Korea Science and Engineering Foundation and by grant no. C-AD15-2006-14- 01 from the Research Program of NVRQS.