المؤلفون: Eunji Park, Brian Leander

المصدر: Parasitology, Vol 151, Pp 400-411 (2024)

مصطلحات موضوعية: apicomplexans, coinfection, gregarines, niche partitioning, polychaetes, tissue tropism, Biochemistry, QD415-436, Infectious and parasitic diseases, RC109-216, Microbiology, QR1-502

الوصف: Individual organisms can host multiple species of parasites (or symbionts), and one species of parasite can infect different host species, creating complex interactions among multiple hosts and parasites. When multiple parasite species coexist in a host, they may compete or use strategies, such as spatial niche partitioning, to reduce competition. Here, we present a host–symbiont system with two species of Selenidium (Apicomplexa, Gregarinida) and one species of astome ciliate co-infecting two different species of slime feather duster worms (Annelida, Sabellidae, Myxicola) living in neighbouring habitats. We examined the morphology of the endosymbionts with light and scanning electron microscopy (SEM) and inferred their phylogenetic interrelationships using small subunit (SSU) rDNA sequences. In the host ‘Myxicola sp. Quadra’, we found two distinct species of Selenidium; S. cf. mesnili exclusively inhabited the foregut, and S. elongatum n. sp. inhabited the mid to hindgut, reflecting spatial niche partitioning. Selenidium elongatum n. sp. was also present in the host M. aesthetica, which harboured the astome ciliate Pennarella elegantia n. gen. et sp. Selenidium cf. mesnili and P. elegantia n. gen. et sp. were absent in the other host species, indicating host specificity. This system offers an intriguing opportunity to explore diverse aspects of host–endosymbiont interactions and competition among endosymbionts.

وصف الملف: electronic resource

العلاقة: https://www.cambridge.org/core/product/identifier/S0031182024000209/type/journal_articleTest; https://doaj.org/toc/0031-1820Test; https://doaj.org/toc/1469-8161Test

الوصول الحر: https://doaj.org/article/09179586c36441ba95a4851afddc4c53Test

المؤلفون: Jong-Uk Lee, Ki Sung Song, Jisu Hong, Hyesun Shin, Eunji Park, Junyeong Baek, Shinhee Park, Ae-Rin Baek, Junehyuk Lee, An Soo Jang, Do Jin Kim, Su Sie Chin, U-Jin Kim, Sung Hwan Jeong, Sung-Woo Park

المصدر: Experimental and Molecular Medicine, Vol 56, Iss 2, Pp 478-490 (2024)

مصطلحات موضوعية: Medicine, Biochemistry, QD415-436

الوصف: Abstract Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung remodeling and the excessive accumulation of extracellular matrix (ECM) proteins. In a previous study, we found that the levels of ornithine aminotransferase (OAT), a principal enzyme in the proline metabolism pathway, were increased in the lungs of patients with IPF. However, the precise role played by OAT in the pathogenesis of IPF is not yet clear. The mechanism by which OAT affects fibrogenesis was assessed in vitro using OAT-overexpressing and OAT-knockdown lung fibroblasts. The therapeutic effects of OAT inhibition were assessed in the lungs of bleomycin-treated mice. OAT expression was increased in fibrotic areas, principally in interstitial fibroblasts, of lungs affected by IPF. OAT levels in the bronchoalveolar lavage fluid of IPF patients were inversely correlated with lung function. The survival rate was significantly lower in the group with an OAT level >75.659 ng/mL than in the group with an OAT level ≤75.659 ng/mL (HR, 29.53; p = 0.0008). OAT overexpression and knockdown increased and decreased ECM component production by lung fibroblasts, respectively. OAT knockdown also inhibited transforming growth factor-β1 (TGF)-β1 activity and TGF-β1 pathway signaling. OAT overexpression increased the generation of mitochondrial reactive oxygen species (ROS) by activating proline dehydrogenase. The OAT inhibitor L-canaline significantly attenuated bleomycin-induced lung injury and fibrosis. In conclusion, increased OAT levels in lungs affected by IPF contribute to the progression of fibrosis by promoting excessive mitochondrial ROS production, which in turn activates TGF-β1 signaling. OAT may be a useful target for treating patients with fibrotic lung diseases, including IPF.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2092-6413Test

الوصول الحر: https://doaj.org/article/af5e4a708dc342ef9ec9cdffe61294e4Test

المؤلفون: Jee‐In Hwang, Ha Jin Tchoe, Soojin Chung, Eunji Park, Miyoung Choi

المصدر: Nursing Open, Vol 10, Iss 1, Pp 337-348 (2023)

مصطلحات موضوعية: Nursing, RT1-120

الوصف: Abstract Aim This study aimed to explore the experiences of quality improvement personnel in implementing clinical pathways (CPs) in Korean hospitals. Design A qualitative study using focus‐group interviews was conducted with healthcare professionals in charge of CP development and management in hospitals. Methods Sixteen quality improvement personnel from eight tertiary and seven general hospitals were recruited using purposive sampling. The verbatim transcribed data were analysed using qualitative content analysis. Results Three key themes emerged: (1) the primary focus of CP development on surgeries through concerted efforts between management and frontline healthcare professionals; (2) CP fidelity management using indicators and feedback to relevant staff or departments; and (3) positive outcomes, despite concerns about system safety. The factors affecting CP use included availability of clinical evidence, flexibility of CPs, top management and clinical leadership, physicians' perceptions of CPs, computerized support systems, and external policies and regulations.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2054-1058Test

الوصول الحر: https://doaj.org/article/2d7bfdfc8ab143b28587c7554febbd70Test

المؤلفون: Eunji Park, Robert Poulin

المصدر: Ecology and Evolution, Vol 12, Iss 10, Pp n/a-n/a (2022)

مصطلحات موضوعية: cryptic species, intracellular parasites, morphological conservatism, species delimitation, substitution saturation, Ecology, QH540-549.5

الوصف: Abstract Some heritable endosymbionts can affect host mtDNA evolution in various ways. Amphipods host diverse endosymbionts, but whether their mtDNA has been influenced by these endosymbionts has yet to be considered. Here, we investigated the role of endosymbionts (microsporidians and Rickettsia) in explaining highly divergent COI sequences in Paracalliope fluviatilis species complex, the most common freshwater amphipods in New Zealand. We first contrasted phylogeographic patterns using COI, ITS, and 28S sequences. While molecular species delimitation methods based on 28S sequences supported 3–4 potential species (N, C, SA, and SB) among freshwater lineages, COI sequences supported 17–27 putative species reflecting high inter‐population divergence. The deep divergence between NC and S lineages (~20%; 28S) and the substitution saturation on the 3rd codon position of COI detected even within one lineage (SA) indicate a very high level of morphological stasis. Interestingly, individuals infected and uninfected by Rickettsia comprised divergent COI lineages in one of four populations tested, suggesting a potential influence of endosymbionts in mtDNA patterns. We propose several plausible explanations for divergent COI lineages, although they would need further testing with multiple lines of evidence. Lastly, due to common morphological stasis and the presence of endosymbionts, phylogeographic patterns of amphipods based on mtDNA should be interpreted with caution.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-7758Test

الوصول الحر: https://doaj.org/article/691fdd458d6d4b27b09f7c203c0fcf9cTest

المؤلفون: Eunji Park, Hojung Choi, Cao-Sang Truong, Hee-Sook Jun

المصدر: Nutrients, Vol 15, Iss 4, p 804 (2023)

مصطلحات موضوعية: muscle atrophy, nelumbo nucifera, pyroptosis, autophagy, protein degradation, Nutrition. Foods and food supply, TX341-641

الوصف: Muscle atrophy is characterized by a decline in muscle mass and function. Excessive glucocorticoids in the body due to aging or drug treatment can promote muscle wasting. In this study, we investigated the preventive effect of Nelumbo nucifera leaf (NNL) ethanolic extract on muscle atrophy induced by dexamethasone (DEX), a synthetic glucocorticoid, in mice and its underlying mechanisms. The administration of NNL extract increased weight, cross-sectional area, and grip strength of quadriceps (QD) and gastrocnemius (GA) muscles in DEX-induced muscle atrophy in mice. The NNL extract administration decreased the expression of muscle atrophic factors, such as muscle RING-finger protein-1 and atrogin-1, and autophagy factors, such as Beclin-1, microtubule-associated protein 1A/1B-light chain 3 (LC3-I/II), and sequestosome 1 (p62/SQSTM1) in DEX-injected mice. DEX injection increased the protein expression levels of NOD-like receptor pyrin domain-containing protein 3 (NLRP3), cleaved-caspase-1, interleukin-1beta (IL-1β), and cleaved-gasdermin D (GSDMD), which were significantly reduced by NNL extract administration (500 mg/kg/day). In vitro studies using C2C12 myotubes also revealed that NNL extract treatment inhibited the DEX-induced increase in autophagy factors, pyroptosis-related factors, and NF-κB. Overall, the NNL extract prevented DEX-induced muscle atrophy by downregulating the ubiquitin–proteasome system, autophagy pathway, and GSDMD-mediated pyroptosis pathway, which are involved in muscle degradation.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2072-6643/15/4/804Test; https://doaj.org/toc/2072-6643Test

الوصول الحر: https://doaj.org/article/e1ef86cc8e194fe7b8d3240a613b7a79Test

المؤلفون: Su Jin Ko, Eunji Park, Alina Asandei, Jee-Young Choi, Seung-Chul Lee, Chang Ho Seo, Tudor Luchian, Yoonkyung Park

المصدر: Scientific Reports, Vol 10, Iss 1, Pp 1-12 (2020)

مصطلحات موضوعية: Medicine, Science

الوصف: Abstract Antimicrobial peptides have attracted attention as alternatives to conventional antibiotics. Previously, a novel antimicrobial peptide, melectin, consisting of 18 amino acids was isolated from the venom of a bee, Melecta albifrons. Here, we investigated the antibacterial activity of melectin against drug-resistant bacteria. Melectin showed broad-spectrum antimicrobial activity but low cytotoxicity and no hemolytic activity. Melectin maintained its antimicrobial activity at physiological salt concentrations. Melectin is an α-helical structure that binds to the bacterial membrane via electrostatic interactions and kills bacteria in a short time by bacterial membrane targeting. Collectively, our results suggest that melectin has antibacterial activity and anti-inflammatory activity.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/bcd81e0dfe3d49aa8b83f3167750b21bTest

المؤلفون: Se-Hun Kim, Ramachandran Chelliah, Sudha Rani Ramakrishnan, Ayyappasamy Sudalaiyadum Perumal, Woo-Suk Bang, Momna Rubab, Eric Banan-Mwine Daliri, Kaliyan Barathikannan, Fazle Elahi, Eunji Park, Hyeon Yeong Jo, Su-Bin Hwang, Deog Hwan Oh

المصدر: Frontiers in Cellular and Infection Microbiology, Vol 10 (2021)

مصطلحات موضوعية: Campylobacter, stress, resistance mechanisms, stress adaptation, enteric bacteria, Microbiology, QR1-502

الوصف: Campylobacter spp. are the leading global cause of bacterial colon infections in humans. Enteropathogens are subjected to several stress conditions in the host colon, food complexes, and the environment. Species of the genus Campylobacter, in collective interactions with certain enteropathogens, can manage and survive such stress conditions. The stress-adaptation mechanisms of Campylobacter spp. diverge from other enteropathogenic bacteria, such as Escherichia coli, Salmonella enterica serovar Typhi, S. enterica ser. Paratyphi, S. enterica ser. Typhimurium, and species of the genera Klebsiella and Shigella. This review summarizes the different mechanisms of various stress-adaptive factors on the basis of species diversity in Campylobacter, including their response to various stress conditions that enhance their ability to survive on different types of food and in adverse environmental conditions. Understanding how these stress adaptation mechanisms in Campylobacter, and other enteric bacteria, are used to overcome various challenging environments facilitates the fight against resistance mechanisms in Campylobacter spp., and aids the development of novel therapeutics to control Campylobacter in both veterinary and human populations.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fcimb.2020.596570/fullTest; https://doaj.org/toc/2235-2988Test

الوصول الحر: https://doaj.org/article/5315d563ed2f4338a01c0f6eba54a7c2Test

المؤلفون: Ganghee Chae, Aram Choi, Soyeoun Lim, Sooneun Park, Seungjun Lee, Youngick Ahn, Jinhyoung Kim, Seungwon Ra, Yangjin Jegal, Jongjoon Ahn, Eunji Park, Jaebum Jun, Woonjung Kwon, Taehoon Lee

المصدر: Tropical Medicine and Infectious Disease, Vol 7, Iss 3, p 51 (2022)

مصطلحات موضوعية: regdanvimab, remdesivir, COVID-19, severe, Medicine

الوصف: Introduction: Coronavirus disease 2019 (COVID-19) still has a high mortality rate when it is severe. Regdanvimab (CT-P59), a neutralizing monoclonal antibody that has been proven effective against mild to moderate COVID-19, may be effective against severe COVID-19. This study was conducted to determine the effectiveness of the combined use of remdesivir and regdanvimab in patients with severe COVID-19. Methods: From March to early May 2021, 124 patients with severe COVID-19 were admitted to Ulsan University Hospital (Ulsan, Korea) and received oxygen therapy and remdesivir. Among them, 25 were also administered regdanvimab before remdesivir. We retrospectively compared the clinical outcomes between the remdesivir alone group [n = 99 (79.8%)] and the regdanvimab/remdesivir group [n = 25 (20.2%)]. Results: The oxygen-free days on day 28 (primary outcome) were significantly higher in the regdanvimab/remdesivir group [mean ± SD: 19.36 ± 7.87 vs. 22.72 ± 3.66, p = 0.003]. The oxygen-free days was also independently associated with use of regdanvimab in the multivariate analysis, after adjusting for initial pulse oximetric saturation (SpO2)/fraction of inspired oxygen (FiO2) ratio (severity index). Further, in the regdanvimab/remdesivir group, the lowest SpO2/FiO2 ratio during treatment was significantly higher (mean ± SD: 237.05 ± 89.68 vs. 295.63 ± 72.74, p = 0.003), and the Kaplan-Meier estimates of oxygen supplementation days in surviving patients (on day 28) were significantly shorter [mean ± SD: 8.24 ± 7.43 vs. 5.28 ± 3.66, p = 0.024]. Conclusions: In patients with severe COVID-19, clinical outcomes can be improved by administering regdanvimab, in addition to remdesivir.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2414-6366/7/3/51Test; https://doaj.org/toc/2414-6366Test

الوصول الحر: https://doaj.org/article/345e273733ce4f3faa7fd0642d7b6af2Test

المؤلفون: Nguyen Sy Pham, Young Hun Seo, Eunji Park, Thao Dang Duy Nguyen, Ik-Soo Shin

المصدر: Data in Brief, Vol 31, Iss , Pp 105891- (2020)

مصطلحات موضوعية: Zinc oxide nanowire, Tungsten trioxide, Electrodeposition, Charge storage capacity, Electrochromic device, Computer applications to medicine. Medical informatics, R858-859.7, Science (General), Q1-390

الوصف: The data presented in this article are related to a research paper entitled “Implementation of High-Performance Electrochromic Device Based on All-Solution-Fabricated Prussian Blue and Tungsten Trioxide Thin Film”[1]. Zinc oxide nanowire (ZnNW) and tungsten trioxide (WO3) were fabricated by different electrodeposition methods and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and used as counter electrodes. The electrochromic (EC) properties of these devices were characterized using optoelectronic analysis during electrochemical applications.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S235234092030785XTest; https://doaj.org/toc/2352-3409Test

الوصول الحر: https://doaj.org/article/effa914824ab4d3782886400fb63c31eTest

المؤلفون: Robert Poulin, Jerusha Bennett, Daniela de Angeli Dutra, Jean-François Doherty, Antoine Filion, Eunji Park, Brandon Ruehle

المصدر: Frontiers in Ecology and Evolution, Vol 8 (2020)

مصطلحات موضوعية: avoidance behavior, comparative analysis, infection risk, parasite-mediated selection, parasite species richness, selection pressure, Evolution, QH359-425, Ecology, QH540-549.5

الوصف: Animals adopt a range of avoidance strategies to reduce their exposure to parasites and the associated cost of infection. If strong selective pressures from parasites are sustained over many generations, avoidance strategies may gradually evolve from phenotypically plastic, or individually variable, to fixed, species-wide traits. Over time, host species possessing effective infection avoidance traits may lose parasite species. Indeed, if overcoming the avoidance strategies of a host species is too costly, i.e., if individuals of that species become too rarely encountered or difficult to infect, a generalist parasite may opt out of this particular arms race. From the host’s perspective, if avoidance traits are not costly or have been co-opted for other functions, they may persist in extant species even if ancestral parasites are lost, as signatures of past selection by parasites. Here, we develop the “ghost of parasitism past” hypothesis. We discuss how animal species with a lower number of parasite species than expected based on their ecological properties or phylogenetic affinities are a good starting point in the search for traces of past parasite-mediated selection. We then argue that the hypothesis explains the dynamic and inconsistent nature of the relationship between the expression of avoidance traits and relative infection risk in comparative analyses across host species. Finally, we propose some approaches to test the predictions of the hypothesis. Animal morphology and behavior show clear evidence of past selective pressures from predators; we argue that past selection from parasites has also left its imprint, though in more subtle ways.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/article/10.3389/fevo.2020.00195/fullTest; https://doaj.org/toc/2296-701XTest

الوصول الحر: https://doaj.org/article/f96dc840a35342e9995c2284bbc76f6eTest