Caught Right on the Spot: Isolation and Characterization of Clade 2.3.4.4b H5N8 High Pathogenicity Avian Influenza Virus from a Common Pochard (Aythya ferina) Being Attacked by a Peregrine Falcon (Falco peregrinus).

We isolated a high pathogenicity avian influenza (HPAI) virus from a common pochard (Aythya ferina) that was being attacked by a bird of prey in South Korea in December 2020. Genetic analyses indicated that the isolate was closely related to the clade 2.3.4.4b H5N8 HPAI viruses found in South Korea and Japan during the winter season of 2020-2021. The histopathological examination revealed multifocal necrotizing inflammation in the liver, kidney, and spleen. Viral antigens were detected in the liver, kidney, spleen, trachea, intestine, and pancreas, indicating the HPAI virus caused a systemic infection. The presence of immunoreactivity for the viral antigen was observed in the cells involved in multifocal necrotic inflammation. Notably, epitheliotropic-positive patterns were identified in the epithelial cells of the trachea, mucosal epithelium of the intestine, and ductular epithelium of the pancreas. These findings provide direct evidence supporting the possibility of HPAI transmission from infected waterfowl to predators.

Detectado en el acto: Aislamiento y caracterización de un virus de la influenza aviar de alta patogenicidad del clado 2.3.4.4b H5N8 de un porrón común (Aythya ferina) atacado por un halcón peregrino (Falco peregrinus). Se aisló un virus de la influenza aviar (HPAI) de alta patogenicidad de un porrón común (Aythya ferina) que estaba siendo atacado por un ave rapaz en Corea del Sur en diciembre de 2020. Los análisis genéticos indicaron que el aislado estaba estrechamente relacionado con virus de influenza aviar de alta patogenicidad H5N8, clado 2.3.4.4 b encontrados en Corea del Sur y Japón durante la temporada de invierno de 2020­2021. El examen histopatológico reveló inflamación necrotizante multifocal en hígado, riñón y bazo. Se detectaron antígenos virales en el hígado, el riñón, el bazo, la tráquea, el intestino y el páncreas, lo que indica que este virus de alta patogenicidad causó una infección sistémica. Se observó la presencia de inmunorreactividad para el antígeno viral en las células involucradas en la inflamación necrótica multifocal. En particular, se identificaron patrones epiteliotrópicos positivos en las células epiteliales de la tráquea, el epitelio mucoso del intestino y el epitelio ductular del páncreas. Estos hallazgos proporcionan evidencia directa que respalda la posibilidad de transmisión de HPAI de aves acuáticas infectadas a especies depredadoras.

Synthesis and Biological Properties of Pyranocoumarin Derivatives as Potent Anti-Inflammatory Agents.

This study aimed to synthesize 23 coumarin derivatives and analyze their anti-inflammatory effects on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages. A cytotoxicity test performed on LPS-induced RAW264.7 macrophages revealed that none of the 23 coumarin derivatives were cytotoxic. Among the 23 coumarin derivatives, coumarin derivative 2 showed the highest anti-inflammatory activity by significantly reducing nitric oxide production in a concentration-dependent manner. Coumarin derivative 2 inhibited the production of proinflammatory cytokines, including tumor necrosis factor alpha and interleukin-6, and decreased the expression level of each mRNA. In addition, it inhibited the phosphorylation of extracellular signal-regulated kinase, p38, c-Jun NH2-terminal kinase, nuclear factor kappa-B p65 (NF-κB p65), and inducible nitric oxide synthase. These results indicated that coumarin derivative 2 inhibited LPS-induced mitogen-activated protein kinase and NF-κB p65 signal transduction pathways in RAW264.7 cells, as well as proinflammatory cytokines and enzymes related to inflammatory responses, to exert anti-inflammatory effects. Coumarin derivative 2 showed potential for further development as an anti-inflammatory drug for the treatment of acute and chronic inflammatory diseases.

Novel Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus in Wild Birds, South Korea.

We isolated 5 highly pathogenic avian influenza A(H5N1) clade 2.3.4.4.b viruses from wild waterfowl feces in South Korea during November 2022. Whole-genome sequencing and phylogenetic analysis revealed novel genotypes produced by reassortment with Eurasian low pathogenicity avian influenza viruses. Enhanced surveillance will be required to improve prevention and control strategies.

Design, Synthesis, and Biological Evaluation of 3-Substituted-Indolin-2-One Derivatives as Potent Anti-Inflammatory Agents.

This study aimed to synthesize and evaluate the anti-inflammatory activity of 3-substituted-indolin-2-one derivatives. Cell viability of 3-substituted-indolin-2-one derivatives was measured with the EZ-Cytox reagent; interleukin (IL)-6, tumor necrosis factor (TNF)-α, and inducible NOS mRNA levels were measured using Taqman qRT-PCR; pro-inflammatory cytokine IL-6 and TNF-α levels were determined using ELISA kits; the phosphorylation of Akt, JNK, ERK, p38, p65, and IκB protein levels were measured by immunoblotting. Among the nineteen 3-substituted-indolin-2-one derivatives synthesized, 3-(3-hydroxyphenyl)-indolin-2-one showed the highest anti-inflammatory activity, inhibiting the nitric oxide production related to inflammation, suppressing the production of TNF-α and IL-6 in a concentration-dependent manner and mRNA expression. Moreover, 3-(3-hydroxyphenyl)-indolin-2-one significantly inhibited lipopolysaccharide (LPS)-induced signal pathways such as the Akt, MAPK, and NF-κB signaling pathways. Our findings revealed that a 3-substituted-indolin-2-one derivative, 3-(3-hydroxyphenyl)-indolin-2-one, possesses excellent anti-inflammatory activity and can be considered for future research.

Novel recombinant avian infectious bronchitis viruses from chickens in Korea, 2019-2021.

Infectious bronchitis virus (IBV) has evolved through various mutation mechanisms, including antigenic drift and recombination. Four genotypic lineages of IBVs including GI-15, GI-16, GI-19, and GVI-1 have been reported in Korea. In this study, we isolated two IBVs from chicken farms, designated IBV/Korea/289/2019 (K289/19) and IBV/Korea/163/2021 (K163/21), which are two distinct natural recombinant viruses most likely produced by genetic reassortment between the S1 gene of K40/09 strain (GI-19 lineage) and IBV/Korea/48/2020 (GI-15 lineage) in co-infected commercial chickens. Comparative sequence analysis of hypervariable regions (HVRs) revealed that the K289/19 virus had similar HVR I and II with the K40/09 virus (100% and 99.2% nucleotide sequence identity, respectively), and HVR III with the IBV/Korea/48/2020 virus (100% nucleotide sequence identity). In contrast, the K163/21 virus had HVR I and II similar to the IBV/Korea/48/2020 virus (99.1% and 99.3% nucleotide sequence identity, respectively), and HVR III to the K40/09 virus (96.6% nucleotide sequence identity). The K289/19 virus exhibited similar histopathologic lesions, tissue tropism in trachea and kidney, and antigenicity with the parental K40/09 virus. The K163/21 exhibited similar pathogenicity and tissue tropism with the K40/09 virus, which were similar results with the isolate K289/19. However, it showed a lower antigenic relatedness with both parental strains, exhibiting R-value of 25 and 42, respectively. The continued emergence of the novel reassortant IBVs suggests that multiple recombination events have occurred between different genotypes within Korea. These results suggest that antigenic profiles could be altered through natural recombination in the field, complicating the antigenic match of vaccine strains to field strains. Enhanced surveillance and research into the characteristics of newly emerging IBVs should be carried out to establish effective countermeasures.

Elucidation of protective effects of oxime derivatives against cisplatin-induced cytotoxicity in LLC-PK1 kidney cells.

This study aimed to explore the renoprotective effects of oxime derivatives against cisplatin-mediated cell death in LLC-PK1 porcine kidney epithelial cells. Treatment with compounds 161-A and 161-F improved cisplatin-mediated LLC-PK1 cell damage and increased cell viability by more than 80% of the control value when compared with that of cisplatin-treated cells. In addition, 161-A and 161-F reduced cisplatin-induced apoptosis. Analysis of the molecular mechanisms underlying the effects exerted by these compounds revealed that treatment with 161-A and 161-B inhibited the protein expression of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) and cleaved caspase-3 in cisplatin-treated LLC-PK1 cells. Thus, these findings provide in vitro scientific evidence that oxime derivatives may be useful as pharmacological candidates for the prevention of cisplatin-mediated nephrotoxicity.

Simultaneous Measurement of Group Refractive Index Dispersion and Thickness of Fused Silica Using a Scanning White Light Interferometer.

In this study, we simultaneously measured the group refractive index dispersion and thickness of fused silica using a scanning white light interferometer on a spectral range from 800 to 1050 nm. A delay error correction was performed using a He-Ne laser. The accuracy of the measured group refractive index dispersion of fused silica, when compared to the temperature-dependent Sellmeier equation, is within 4 × 10-5.

Six New Polyoxygenated Xanthones from Garcinia cowa and Their Neuroprotective Effects on Glutamate-Mediated Hippocampal Neuronal HT22 Cell Death.

Six new polyoxygenated xanthones, garcicowanones F-H (1-3), norcowanol A-B (4-5), and garcinone F (6) along with twelve known compounds 7-18 were obtained from the latex of Garcinia cowa Roxb. ex Choisy. All new compounds have a 1,3,7-trioxygenated or 1,3,6,7-tetraoxygenated xanthone nucleus and differ from majority of xanthones from G. cowa by hydrated side chains. Compounds 1, 7, 8 and 18 exhibited significant neuroprotective effects on glutamate-mediated hippocampal neuronal HT22 cell death. In particular, compound 1 exhibited the most potent neuroprotective effect with >80 % cell viability in the concentration range of 2.9-115 µM. Further studies on compound 1 showed that it decreased cellular Ca2+ influx and inhibits cellular reactive oxygen species generation in HT22 cells. A Western blot analysis showed that MAPK phosphorylation, Bax, and AIF translocation dramatically increased upon treatment with 5 mM glutamate and decreased upon a co-treatment with compound 1.

Ideal Nozzle Position During Pressurized Intraperitoneal Aerosol Chemotherapy in an Ex Vivo Model.

BACKGROUND/AIM: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is known to show uneven distribution and penetration of agents based on the nozzle position. Thus, this study aimed to investigate the ideal nozzle position for maximizing drug delivery during PIPAC. MATERIALS AND METHODS: We created 2 cm-, 4 cm- and 8 cm-ex vivo models according to the distance from the bottom to the nozzle using 21×15×16 cm-sized sealable plastic boxes. After each set of eight normal peritoneal tissues from swine were placed at eight different points (A to H), we performed PIPAC, compared the methylene blue staining areas to investigate the distribution, and estimated the depth of concentrated diffusion (DCD) and the depth of maximal diffusion (DMD) of doxorubicin. RESULTS: In terms of distribution, the 4 cm- and 8 cm-ex vivo models showed more stained faces than the 2 cm-ex vivo model. Regarding the penetration depth, the 4 cm- ex vivo model showed the highest DCD (mean; 244.1 µm, C; 105.1 µm, D; 80.9 µm, E; 250.2 µm, G; 250.2 µm, H) and DMD (mean; 174.8 µm, D; 162.7 µm, E; 511.7 µm, F; 522.2 µm, G; 528.1 µm, H) in the most points corresponding to 62.5%. CONCLUSION: The ideal nozzle position during PIPAC might be halfway between the nozzle inlet and the bottom in the ex vivo model.

Neuroprotective effects of 2-heptyl-3-hydroxy-4-quinolone in HT22 mouse hippocampal neuronal cells.

The neuroprotective activity of 2-heptyl-3-hydroxy-4(1H)-quinolone (compound 1) was evaluated using the neurotoxicity of glutamate in the HT22 cell line. Compound 1, known as a signal molecule of the bacterial quorum-sensing system, protects neuronal cells from glutamate-induced neurotoxicity by inhibiting cellular Ca2+ uptake and glutamate-triggered ROS accumulation. MAPK signaling pathway inhibition by compound 1 was evaluated by immunoblotting the phosphorylation status of the proteins. Furthermore, pro-apoptotic protein levels and AIF translocation to the nucleus were found to be reduced by compound 1. In conclusion, compound 1 showed neuroprotective effects by inhibiting apoptotic neuronal cell death.

Necrostatins regulate apoptosis, necroptosis, and inflammation in cisplatin-induced nephrotoxicity in LLC-PK1 cells.

Acute kidney injury (AKI) is a common clinical problem that is associated with high mortality due to multiple complex mechanisms. Cisplatin is the most important and highly effective chemotherapeutic agent used for the treatment of various solid tumors; however, it is associated with dose-dependent adverse effects, particularly in the kidney where it can cause severe nephrotoxicity. The pathophysiological basis of cisplatin-induced nephrotoxicity has been investigated over the last few decades, and the key pathological occurrences in cisplatin nephrotoxicity include renal tubular cell injury and death. Necrostatin-1 (Nec-1) has been confirmed to act as a specific and potent small-molecule inhibitor of necroptosis. However, the effects of three structurally distinct necrostatins on cisplatin-induced nephrotoxicity remain ambiguous. The aim of this study was to determine if three types of necrostatins (Nec-1, Nec-3-A, and/or Nec-3-B) can exert protective effects in regard to the AKI induced by cisplatin. Our results indicated that necrostatins can prevent cisplatin induced nephrotoxicity via modulating apoptotic pathways through the suppression of cleaved caspase-3 and also by influencing the function of mitogen-activated protein kinase pathway members, including extracellular signal-regulated kinases, c-Jun N-terminal kinases, and p38, in the renal tubular epithelial cell line LLC-PK1. These findings suggest that necrostatins exert beneficial anti-apoptotic effects in the context of AKI induced by cisplatin.

Synthesis and biological evaluation of chalcone derivatives as neuroprotective agents against glutamate-induced HT22 mouse hippocampal neuronal cell death.

Seventeen chalcone analogues were synthesized from 7-methoxy-3,4-dihydronaphthalen1(2H)-one and various aromatic aldehydes under basic conditions and their therapeutic properties were studied in mouse hippocampal cell line HT-22 against neuronal cell death induced by glutamate. From this study, we selected an analogue C01 as a active compound which showed significantly high neuroprotection. This compound inhibited Ca2+ influx and reactive oxygen species (ROS) accumulation inside cells. The glutamate-induced cell death was analyzed by flow cytometry and it showed that C01 significantly reduced apoptotic or dead cell induced by 5 mM glutamate. Western blot analysis indicates that glutamate-mediated activation of MAPKs were inhibited by compound C01 treatment. In addition, the C01enhanced Bcl-2 and decreased Bax, the anti and pro apoptotic proteins respectively. Further analysis showed that, C01 prevented the nuclear translocation of AIF (apoptosis inducing factor) and inhibited neuronal cell death. Taken together, compound C01 treatment resulted in decreased neurotoxicity induced by 5 mM of glutamate. Our finding confirmed that compound C01 has neuro-therapeutic potential against glutamate-mediated neurotoxicity.

How Psychological Safety Affects Team Performance: Mediating Role of Efficacy and Learning Behavior.

This article examines the mechanisms that influence team-level performance. It investigates psychological safety, a shared belief that the team is safe for interpersonal risk taking and a causal model mediated by learning behavior and efficacy. This model hypothesizes that psychological safety and efficacy are related, which have been believed to be same-dimension constructs. It also explains the process of how learning behavior affects the team's efficacy. In a study of 104 field sales and service teams in South Korea, psychological safety did not directly affect team effectiveness. However, when mediated by learning behavior and efficacy, a full-mediation effect was found. The results show (i) that psychological safety is the engine of performance, not the fuel, and (ii) how individuals contribute to group performance under a psychologically safe climate, enhancing team processes. Based on the findings, this article suggests theoretical and methodological implications for future research to maximize teams' effectiveness.

Synthesis and biological evaluation of isoliquiritigenin derivatives as a neuroprotective agent against glutamate mediated neurotoxicity in HT22 cells.

Glutamate-induced neurotoxicity is characterized by cellular Ca2+ uptake, which is upstream of reactive oxygen species (ROS)-induced apoptosis signaling and MAPKs activation. In the present study, we synthesized isoliquiritigenin analogs with electron-donating and electron-withdrawing functional groups. These analogs were evaluated for neuroprotective effect against glutamate-induced neurotoxicity in HT22 cells. Among these analogs, compound BS11 was selected as a potent neuroprotective agent. Cellular Ca2+ concentration, ROS level, MAPKs activation and AIF translocation to the nucleus were increased upon treatment with 5 mM glutamate. In contrast, we identified that compound BS11 reduced the cellular Ca2+ concentration and ROS level upon glutamate exposure. Western blot analysis showed that MAPK activation was decreased by treatment with compound BS11. We further identified that cotreatment of compound BS11 and glutamate inhibited translocation of AIF to the nucleus.

Effect of Weissella cibaria on the reduction of periodontal tissue destruction in mice.

BACKGROUND: Periodontitis is associated with dysbiosis of microbial flora in the oral cavity. We evaluated the effects of an oral care probiotic, Weissella cibaria CMU, on periodontal tissue destruction and regulation of inflammatory cytokines in mice with ligature-induced periodontitis (LIP). METHODS: Fourteen-day LIP model was used. Ninety animals were randomly divided into six groups: negative control (Ctrl), positive control (LIP/Ctrl), PBS-treated (LIP/PBS), W. cibaria-low (1 × 107 colony forming unit (CFU)/d; LIP/WC-L), W. cibaria-medium (1 × 108 CFU/d; LIP/WC-M), and W. cibaria-high (1 × 109  CFU/d; LIP/WC-H). After the 14-day treatment, alveolar bone loss was determined using micro-computed tomography. The gingival tissue and serum samples from Ctrl, LIP/Ctrl, and LIP/WC-H groups were immunoassayed for cytokines. Measurements of Porphyromonas gingivalis, total bacteria, and W. cibaria in the gingiva were performed using real-time polymerase chain reaction. RESULTS: Mice in the LIP/WC-H group showed significant reduction in alveolar bone loss at the distal aspect of the ligatured teeth compared to those in the LIP/Ctrl group. There was a dose-dependent reduction (non-significant) in periodontal tissue destruction with increased W. cibaria concentration. Pro- and anti-inflammatory cytokines were significantly lower in LIP/WC-H than in LIP/Ctrl. The LIP/WC-H group showed significantly fewer total bacteria compared to the LIP/Ctrl group but it was similar to that in Ctrl groups, and P. gingivalis was not detected in the gingival tissue. CONCLUSIONS: W. cibaria CMU reduces periodontal tissue destruction apparently by regulating the production of inflammatory cytokines and by reducing oral bacteria in a model for periodontal disease.

Ginsenoside Rb2 suppresses the glutamate-mediated oxidative stress and neuronal cell death in HT22 cells.

BACKGROUND: The objective of our study was to analyze the neuroprotective effects of ginsenoside derivatives Rb1, Rb2, Rc, Rd, Rg1, and Rg3 against glutamate-mediated neurotoxicity in HT22 hippocampal mouse neuron cells. METHODS: The neuroprotective effect of ginsenosides were evaluated by measuring cell viability. Protein expressions of mitogen-activated protein kinase (MAPK), Bcl2, Bax, and apoptosis-inducing factor (AIF) were determined by Western blot analysis. The occurrence of apoptotic and death cells was determined by flow cytometry. Cellular level of Ca2+ and reactive oxygen species (ROS) levels were evaluated by image analysis using the fluorescent probes Fluor-3 and 2',7'-dichlorodihydrofluorescein diacetate, respectively. In vivo efficacy of neuroprotection was evaluated using the Mongolian gerbil of ischemic brain injury model. RESULT: Reduction of cell viability by glutamate (5 mM) was significantly suppressed by treatment with ginsenoside Rb2. Phosphorylation of MAPKs, Bax, and nuclear AIF was gradually increased by treatment with 5 mM of glutamate and decreased by co-treatment with Rb2. The occurrence of apoptotic cells was decreased by treatment with Rb2 (25.7 µM). Cellular Ca2+ and ROS levels were decreased in the presence of Rb2, and in vivo data indicated that Rb2 treatment (10 mg/kg) significantly diminished the number of degenerated neurons. CONCLUSION: Our results suggest that Rb2 possesses neuroprotective properties that suppress glutamate-induced neurotoxicity. The molecular mechanism of Rb2 is by suppressing the MAPKs activity and AIF translocation.

CpG-DNA induces bacteria-reactive IgM enhancing phagocytic activity against Staphylococcus aureus infection.

CpG-DNA triggers the proliferation and differentiation of B cells which results in the increased production of antibodies. The presence of bacteria-reactive IgM in normal serum was reported; however, the relevance of CpG-DNA with the production of bacteria-reactive IgM has not been investigated. Here, we proved the function of CpG-DNA for the production of bacteria-reactive IgM. CpG-DNA administration led to increased production of bacteria-reactive IgM both in the peritoneal fluid and serum through TLR9 signaling pathway. When we stimulated B cells with CpG-DNA, production of bacteria-reactive IgM was reproduced in vitro. We established a bacteria-reactive monoclonal IgM antibody using CpG-DNA stimulated-peritoneal B cells. The monoclonal IgM antibody enhanced the phagocytic activity of RAW 264.7 cells against S. aureus MW2 infection. Therefore, we suggest that CpG-DNA enhances the antibacterial activity of the immune system by triggering the production of bacteria-reactive IgM. We also suggest the possible application of the antibodies for the treatment of antibiotics-resistant bacterial infections. [BMB Reports 2019; 52(11): 635-640].

CpG-DNA exerts antibacterial effects by protecting immune cells and producing bacteria-reactive antibodies.

CpG-DNA activates various immune cells, contributing to the host defense against bacteria. Here, we examined the biological function of CpG-DNA in the production of bacteria-reactive antibodies. The administration of CpG-DNA increased survival in mice following infection with methicillin-resistant S. aureus and protected immune cell populations in the peritoneal cavity, bone marrow, and spleen. CpG-DNA injection likewise increased bacteria-reactive antibodies in the mouse peritoneal fluid and serum, which was dependent on TLR9. B cells isolated from the peritoneal cavity produced bacteria-reactive antibodies in vitro following CpG-DNA administration that enhanced the phagocytic activity of the peritoneal cells. The bacteria-reactive monoclonal antibody enhanced phagocytosis in vitro and protected mice after S. aureus infection. Therefore, we suggest that CpG-DNA enhances the antibacterial activity of the immune system by protecting immune cells and triggering the production of bacteria-reactive antibodies. Consequently, we believe that monoclonal antibodies could aid in the treatment of antibiotic-resistant bacterial infections.