What influenced frontline nurses' mental health during the early phase of the COVID-19 pandemic.

AIM: This cross-sectional study aimed to investigate the factors that affected the mental health of Korean nurses caring for coronavirus disease 2019 (COVID-19) patients, causing posttraumatic stress disorder, depression, anxiety, and sleep disorders. BACKGROUND: Infectious disease outbreaks like COVID-19 affect the mental health not only of those who contract the disease but also of nurses caring for affected patients. INTRODUCTION: To address health issues effectively, it is essential to comprehend how to prevent them. Therefore, it is necessary to scrutinize the origins of COVID-19-related health concerns and devise measures to prevent potential problems. METHOD: We used an online survey to collect data from 136 nurses caring for COVID-19 patients during the initial stage of the pandemic. The data were analyzed using the one-way analysis of variance and a simple logistic regression. RESULTS: The findings confirmed a high prevalence of posttraumatic stress disorder among nurses, with symptoms of depression, anxiety, and sleep problems. DISCUSSION: Our research has shown that it is important not to exacerbate the difficulties that nurses face after their activities. Therefore, it proposes for creating environmental structures that mitigate predictable challenges such as workload from various tasks, sleep disturbances, and hopelessness, rather than focusing on personal vulnerabilities. CONCLUSION: Timely attention to influencing factors can reduce the risk to nurses' mental health, so we need to plan preventive measures that reflect the influencing factors to prepare for future pandemics. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Continuous monitoring of the mental health status of nurses responding to a global health crisis and the development of appropriate psychological support programs and policies for creating a conducive work environment are necessary.

Functional characterization and gene expression profile of perforin-2 in starry flounder (Platichthys stellatus).

The membrane attack complex/perforin (MACPF) superfamily consists of multifunctional proteins that form pores on the membrane surface of microorganisms to induce their death and have various immune-related functions. PFN2 is a perforin-like protein with an MACPF domain, and humans with deficient PFN2 levels have increased susceptibility to bacterial infection, which can lead to fatal consequences for some patients. Therefore, in this study, we confirmed the antimicrobial function of PFN2 in starry flounder (Platichthys stellatus). The molecular properties were confirmed based on the verified amino acid sequence of PsPFN2. In addition, the expression characteristics of tissue-specific and pathogen-specific PsPFN2 mRNA were also confirmed. The recombinant protein was produced using Escherichia coli, and the antimicrobial activity was then confirmed. The coding sequence of PFN2 (PsPFN2) in P. stellatus consists of 710 residues. The MACPF domain was conserved throughout evolution, as shown by multiple sequence alignment and phylogenetic analysis. PsPFN2 mRNA is abundantly distributed in immune-related organs such as the spleen and gills of healthy starry flounder, and significant expression changes were confirmed after artificial infection by bacteria or viruses. We cloned the MACPF domain region of PFN2 to produce a recombinant protein (rPFN2) and confirmed its antibacterial effect against a wide range of bacterial species and the parasite (Miamiensis avidus).

Functional analysis and gene expression profiling of extracellular cathepsin Z in red sea bream, Pagrus major.

Cathepsin Z (CTSZ) is a lysosomal cysteine protease that is known to be involved in the maintenance of homeostasis and the biological mechanisms of immune cells. In this study, we have confirmed the tissue specific expression of the cathepsin Z (PmCTSZ) gene in Pagrus major, and confirmed its biological function after producing recombinant protein using Escherichia coli (E. coli). Multiple sequence alignment analysis revealed that the active site of the cysteine proteases and three N-glycosylation sites of the deduced protein sequence were highly conserved among all of the organisms. Phylogenetic analysis revealed that PmCTSZ was included in the clusters of CTSZ and the cysteine proteases of other bony fish and is most closely related to Japanese flounder CTSZ. PmCTSZ was distributed in all of the tissues from healthy red sea bream that were used in the experiment and was most abundantly found in the spleen and gill. Analysis of mRNA expression after bacterial (Edwardsiella piscicida: E. piscicida and Streptococcus iniae: S. iniae) or viral (red seabream iridovirus: RSIV) challenge showed significant gene expression regulation in immune-related tissues, but they maintained relatively normal levels of expression. We produced recombinant PmCTSZ (rPmCTSZ) using an E. coli expression system and confirmed the biological function of extracellular rPmCTSZ in vitro. We found that bacterial proliferation was significantly inhibited by rPmCTSZ, and the leukocytes of red sea bream also induced apoptosis and viability reduction.

Olive flounder CD276 (B7-H3) a coinhibitory molecule for T cells: Responses during viral hemorrhagic septicemia virus (VHSV) stimulation.

Coinhibitory pathways in the B7-CD28 family provide critical inhibitory signals that regulate immune homeostasis, defense and protect tissue integrity. CD276 (B7-H3) is an important immune checkpoint member of this family, which is induced on antigen-presenting cells (APCs), and plays an important role in the inhibition of T-cell function. We have characterized the CD276 gene of olive flounder, Paralichthys olivaceus. OfCD276 has an ORF of 912 bp that codes for 303 amino acids with a predicted molecular mass of 33 kDa. It is a type I transmembrane protein with a single extracellular V- and C-like Ig domains, a transmembrane region, and a highly diverse cytoplasmic tail. This gene was distinctly expressed in gill, spleen, and skin, and sparsely expressed in other tissues. Pathogen stimulation by VHSV revealed that transcription of OfCD276 was induced on early hours in liver and expressed late in head kidney, spleen, intestine and gill tissues. Flow cytometry analysis of leukocytes revealed the percentage of granulocytes and lymphocytes that expressed OfCD276 molecules on their cell surface was 85.1% and 3.1%, respectively. Our study shows a significant role played by this coinhibitory molecule that participate in the regulation of the cell mediated immune response.

Molecular characterization, expression and functional analysis of peptidoglycan recognition protein-SC2 from rock bream, Oplegnathus fasciatus.

Peptidoglycan recognition proteins are members of the family of pattern recognition receptors (PRRs), that play important roles in the recognition of peptidoglycan and various biological processes. In this study, we have characterized peptidoglycan recognition protein-SC2 (PGRP-SC2) in rock bream (Oplegnathus fasciatus) (RbPGRP-SC2) and analysed its expression in various tissues after pathogen challenge. A sequence alignment revealed that the residues essential to zinc binding of the deduced protein were highly conserved among all the organisms. Phylogenetic analysis revealed that RbPGRP-SC2 is most closely related to the large yellow croaker PGRP-SC2. RbPGRP-SC2 was ubiquitously expressed in all tissues analysed, predominantly distributed in muscle and skin. After challenge with microbial pathogens (Edwardsiella piscicida), Streptococcus iniae or red seabream iridovirus [RSIV]), RbPGRP-SC2 was up-regulated in all the tissues examined, especially in liver. We produced recombinant RbPGRP-SC2 (rRbPGRP-SC2) using an Escherichia coli expression system. The rRbPGRP-SC2 had agglutination activity towards both Gram-negative (E. piscicida) and Gram-positive bacteria (S. iniae). In addition, rRbPGRP-SC2 induced leukocyte apoptosis and promoted leukocyte phagocytosis. These results suggest that the RbPGRP-SC2 plays an important role in the immune system and in maintaining cellular homeostasis of rock bream.

The first report of CD2 associated protein gene, in a teleost (Rock bream, Oplegnathus fasciatus): An investigation of the immune response upon infection with several pathogens.

CD2 is expressed on the surfaces of virtually all T cells and natural killer (NK) cells. In mammals, the CD2 molecule is 50 kDa. The cytoplasmic tail of CD2 interacts with CD2-associated protein (CD2AP), which plays an important role in mediating the trigger signal in outer magnetic pole cells. In this study, we identified CD2AP from rock bream and investigated its gene expression. The ORF of CD2AP (1950 bp) encodes 650 amino acids (aa). CD2AP has a Src homology 3 (SH3) domain. Quantitative real-time PCR analysis revealed that CD2AP shows higher expression in the gills and skin. Under experimental challenge, CD2AP gene expression was increased as relative to the control after 7 days. This result will improve our understanding of blood vessels in teleost fish, and will provide a basis for the study of CD2-related genes.

Coagulation factor II from rock bream (Oplegnathus fasciatus): First report on the molecular biological function and expression analysis in the teleost.

The rapid haemostasis of fish prevents bleeding or infection that could be caused by physical properties of the aquatic environment. Additionally, the innate immune system is the first line of defence against infection and is responsible for the recognition of pathogen-associated molecular patterns, which are important for the activation of acquired immune responses. Coagulation factor II (CFII) is an important factor in the coagulation system and is involved in recognition and interaction with various bacterial and extracellular proteins. In this study, we identified and characterised the gene encoding CFII in rock bream (Oplegnathus fasciatus) (RbCFII) and analysed its expression in various tissues after a pathogen challenge. The full-length RbCFII cDNA (2079 bp) contained an open reading frame of 1854 bp encoding 617 amino acids. Alignment analysis revealed that a gamma-carboxyglutamic acid-rich domain, two kringle domains, and a trypsin-like serine protease domain of the deduced protein were well conserved. RbCFII was ubiquitously expressed in all tissues examined but, predominantly detected in the liver and skin. RbCFII expression was dramatically up-regulated in the kidney, spleen and liver after infection with Edwardsiella tarda, Streptococcus iniae, or red seabream iridovirus. The recombinant protein RbCFII (rRbCFII) produced using an Escherichia coli expression system was able to bind all examined bacteria. Interestingly, rRbCFII has agglutination activities towards E. coli and E. tarda, while no agglutination was shown toward Vibrio ordalii and S. iniae. These findings indicate that rRbCFII performs an immunological function in the immune response, and might be involved in innate immunity as well as blood coagulation.

Evolutionary Approach to Optimal Oil Skimmer Assignment for Oil Spill Response: A Case Study.

We propose a genetic algorithm for optimizing oil skimmer assignments, introducing a tailored repair operation for constrained assignments. Methods essentially involve simulation-based evaluation to ensure adherence to South Korea's regulations. Results show that the optimized assignments, compared to current ones, reduced work time on average and led to a significant reduction in total skimmer capacity. Additionally, we present a deep neural network-based surrogate model, greatly enhancing efficiency compared to simulation-based optimization. Addressing inefficiencies in mobilizing locations that store oil skimmers, further optimization aimed to minimize mobilized locations and was validated through scenario-based simulations resembling actual situations. Based on major oil spills in South Korea, this strategy significantly reduced work time and required locations. These findings demonstrate the effectiveness of the proposed genetic algorithm and mobilized location minimization strategy in enhancing oil spill response operations.

A sero-epidemiological analysis of Coxiella burnetii infection and its risk factors in livestock from Addis Ababa, Adama, and Modjo abattoirs and pastoral areas of Oromia, Ethiopia.

BACKGROUND: Coxiella burnetii is causing infections in both humans and animals, resulting in Q fever and Coxiellosis, respectively. Information on the occurrence of C. burnetii infection is scarce in Ethiopia. This study estimated the sero-prevalence of C. burnetii infection and associated risk factors in four common livestock species from Addis Ababa, Adama, and Modjo abattoirs and pastoral areas of Oromia, Ethiopia. RESULTS/PRINCIPAL FINDINGS: Sera samples were analyzed for the presence of anti-C. burnetii antibodies using an indirect Enzyme Linked Immunosorbent Assay kit. Out of the 4140 serum samples tested, 777 (18.77%; 95% CI: 17.59, 19.99) were found positive for C. burnetii. The sero-prevalence estimate was 27.17% at Addis Ababa abattoir, 19.41% at Adama abattoir, 19.13% at Modjo abattoir and 12.1% in animals tested from pastoral areas. Sera analysis at the animal species level showed that cattle exhibited the lowest sero-prevalence estimate (11.83%; 95% CI, 10.27-13.53%), while the highest was observed in camels (28.39%; 95% CI, 25.16-31.80%). The sero-prevalence estimate was 21.34% (95% CI, 18.86-23.99%) in goats and 20.17% (95% CI, 17.49-23.07%) in sheep. The results of multivariable logistic regression analysis showed that species, age, sex of animals and tick infestation were important risk factors for C. burnetii infection. The odds of infection were 3.22 times higher in camels and almost twice as high in goats and sheep compared to cattle. Adult animals were infected more likely (OR = 3.23) than young ones. Interestingly, a significant difference was observed in the sero-prevalence of infection between animals that were infested with ticks (OR = 16.32) and those which were tick-free. CONCLUSION: This study provides valuable insights into the sero-epidemiology of C. burnetii infection in four common livestock species at major abattoirs and pastoral areas of Ethiopia. The findings highlight the need for further studies and implementing surveillance and biosecurity measures to prevent the spread of the disease in both humans and livestock to safeguard the economical and public health aspects.

Melatonin receptor 1 B polymorphisms associated with the risk of gestational diabetes mellitus.

BACKGROUNDS: Two SNPs in melatonin receptor 1B gene, rs10830963 and rs1387153 showed significant associations with fasting plasma glucose levels and the risk of Type 2 Diabetes Mellitus (T2DM) in previous studies. Since T2DM and gestational diabetes mellitus (GDM) share similar characteristics, we suspected that the two genetic polymorphisms in MTNR1B may be associated with GDM, and conducted association studies between the polymorphisms and the disease. Furthermore, we also examined genetic effects of the two polymorphisms with various diabetes-related phenotypes. METHODS: A total of 1,918 subjects (928 GDM patients and 990 controls) were used for the study. Two MTNR1B polymorphisms were genotyped using TaqMan assay. The allele distributions of SNPs were evaluated by x2 models calculating odds ratios (ORs), 95% confidence intervals (CIs), and corresponding P values. Multiple regressions were used for association analyses of GDM-related traits. Finally, conditional analyses were also performed. RESULTS: We found significant associations between the two genetic variants and GDM, rs10830963, with a corrected P value of 0.0001, and rs1387153, with the corrected P value of 0.0008. In addition, we also found that the two SNPs were associated with various phenotypes such as homeostasis model assessment of beta-cell function and fasting glucose levels. Further conditional analyses results suggested that rs10830963 might be more likely functional in case/control analysis, although not clear in GDM-related phenotype analyses. CONCLUSION: There have been studies that found associations between genetic variants of other genes and GDM, this is the first study that found significant associations between SNPs of MTNR1B and GDM. The genetic effects of two SNPs identified in this study would be helpful in understanding the insight of GDM and other diabetes-related disorders.

Molecular Identification and mRNA Expression Profiles of Galectin-9 Gene in Red Sea Bream (Pagrus major) Infected with Pathogens.

Galectin (Gal) is a member of a family of ß-galactoside-binding lectin. The members of this family play important roles in the recognition of carbohydrate ligands and in various other biological processes. In this study, we identified the gene encoding Gal-9 in Pagrus major (PmGal-9) and analyzed its expression in various tissues after pathogen challenge. Alignment analysis revealed that the two galactose-binding lectin domains of the deduced protein were highly conserved among all the teleosts. Phylogenetic analysis revealed that PmGal-9 is most closely related to the Gal-9 gene of gilthead sea bream. PmGal-9 was ubiquitously expressed in all tissues analyzed but was predominantly expressed in the spleen, head kidney, and intestine. After challenges with major microbial pathogens (Edwardsiella piscicida, Streptococcus iniae, or red sea bream iridovirus) of red sea bream, PmGal-9 mRNA expression was significantly regulated in most immune-related tissues. These results suggested that PmGal-9 not only plays an important role in the immune system of red sea bream but is also a possible inflammatory marker for pathogenic diseases.

B-cell epitope specificity of carboxy terminus of Mycobacterium paratuberculosis ModD.

Epitope mapping of ModD of Mycobacterium paratuberculosis was performed using overlapping peptides. In total, 80 overlapping peptides, covering the entire mature ModD, were commercially synthesized. Each peptide spanned 14 amino acids with an offset of 4 amino acids, i.e., with an overlap of 10 amino acids. Synthetic peptide antigenicity was evaluated by enzyme-linked immunosorbent assay (ELISA) using rabbit antisera to culture filtrate (CF) of M. avium or M. paratuberculosis or recombinant ModD (rModD). The peptides o f ModD reacting most strongly (ELISA OD > 1.0) were clustered near the N- and C-terminal ends. The peptides around the C-terminal end only showed the greatest specificity for M. paratuberculosis, yielding high ELISA OD values with rabbit anti-M. paratuberculosis CF serum and low ELISA OD values with rabbit anti-M. avium CF serum. Sera from naturally M. paratuberculosis-infected cattle, however, bound poorly to the short, 14-amino-acid peptides. Thus, two longer peptides covering amino acids 100 to 125 and 328 to 353 were synthesized based on their broad reactivity to rabbit serum against M. paratuberculosis CF. The peptide covering amino acids 328 to 353 showed the highest level of specific bovine antibody binding.

Quantitative Rose Bengal Test for diagnosis of bovine brucellosis.

The Rose Bengal Test (RBT) is the most widely used screening test for brucellosis in both humans and animals. Owing to its apparent simplicity of reading, however, interpretations of the RBT results can be affected by personal experience. This study describes a simple way to improve the accuracy and uniformity of reading the RBT reaction by counting the number of agglutinated particles using transparent OHP film with Quantity One, which was originally designed to count the bacterial colony numbers on agar plates. Using this system, the reactivities of three Rose Bengal antigens from different sources against international standard serum (1,000 units, VLA, UK) could be numerically measured: the intensity scale ranged from zero to around 1,600. This system enabled us to compare the antigenicity of Rose Bengal antigens from three different sources by using statistical analyses such as regression and mean intensity. Collectively, mathematical measuring of the reaction intensity used in this study may help interpret subtle test results by providing more reliable data and additional statistical information on the herd. In addition, the method would also be applicable to other agglutination test for other diseases.

The First Detection of Kudoa hexapunctata in Farmed Pacific Bluefin Tuna in South Korea, Thunnus orientalis (Temminck and Schlegel, 1844).

The consumption of fish and shellfish worldwide is steadily increasing, and tuna is a particularly valuable fish species. However, infection caused by Kudoa spp. is causing problems in many fish including the Pacific bluefin tuna (Thunnus orientalis), and there is much controversy about the association of these infections with foodborne disease. In this study, using haematological and histological analyses of the blood and internal organs (liver, spleen, kidney, heart, stomach, intestine, gill, and muscle) of Pacific bluefin tuna cultured in South Korea, infection with Myxosporea was first identified, and molecular biological analysis was conducted. In this study, Kudoa hexapunctata was finally identified. The Pacific bluefin tunas analysed in this study did not show any gross pathology lesions, such as visible cysts and/or myoliquefaction, of infection with this species. The histological analytical results can provide guidelines for the identification of K. hexapunctata. In the case of K. hexapunctata-induced infection, unlike other countries, such as Japan, there have been no reports in South Korea, and this study is the first to detect K. hexapunctata infection in Pacific bluefin tuna cultured in South Korea. The correlation between K. hexapunctata and food poisoning is not yet clear, however, it is thought that continuous observation of its infection is necessary.

The molecular characterization, expression analysis and antimicrobial activity of theromacin from Asian polychaeta (Perinereis linea).

Antimicrobial peptides (AMPs) are molecular factors in innate immunity and are believed to play a key role in invertebrate host defence. We identified theromacin (TM) from an Asian polychaeta, Perinereis linea, using de novo RNA-seq analysis. TM, a typical AMP of invertebrates, is a cysteine-rich AMP with five disulfide bonds consisting of ten cysteine residues. In gene expression analysis, TM genes were constantly upregulated after lipopolysaccharide (LPS) stimulation. In contrast, after peptidoglycan (PGN) stimulation, it was upregulated initially and downregulated after 12 h. We synthesized a peptide based on the macin AMP in the TM amino acid sequence. The synthetic peptide showed antibacterial activity against some Gram-positive and Gram-negative bacteria. Therefore, the AMPs of P. linea might have broad roles in host defence and exhibit different degrees of activity.

Application and evaluation of the MLVA typing assay for the Brucella abortus strains isolated in Korea.

BACKGROUND: A Brucella eradication program has been executed in Korea. To effectively prevent and control brucellosis, a molecular method for genetic identification and epidemiological trace-back must be established. As part of that, the MLVA typing assay was evaluated and applied to B. abortus isolates for analyzing the characteristics of the regional distribution and relationships of foreign isolates. RESULTS: A total of 177 isolates originating from 105 cattle farms for the period 1996 to 2008 were selected as representatives for the nine provinces of South Korea. A dendrogram of strain relatedness was constructed in accordance with the number of tandem repeat units for 17 loci so that it was possible to trace back in the restricted areas. Even in a farm contaminated by one source, however, the Brucella isolates showed an increase or decrease in one TRs copy number at some loci with high DI values. Moreover, those 17 loci was confirmed in stability via in-vitro and in-vivo passage, and found to be sufficiently stable markers that can readily identify the inoculated strain even if minor changes were detected. In the parsimony analysis with foreign Brucella isolates, domestic isolates were clustered distinctively, and located near the Central and Southern American isolates. CONCLUSION: The MLVA assay has enough discrimination power in the Brucella species level and can be utilized as a tool for the epidemiological trace-back of the B. abortus isolates. But it is important to consider that Brucella isolates may be capable of undergoing minor changes at some loci in the course of infection or in accordance with the changes of the host.

Definition of purified enzyme-linked immunosorbent assay antigens from the culture filtrate protein of Mycobacterium bovis by proteomic analysis.

Enzyme-linked immunosorbent assay (ELISA) has been developed as the ancillary diagnosis of bovine tuberculosis at ante-mortem to overcome the disadvantages of intradermal skin test. In this study, the antigenic proteins were purified, applied to bTB ELISA, and identified through proteomic analysis. Culture filtrate protein of Mycobacterium bovis was fractionated by MonoQ column chromatography, and examined the antigenicity by immunoblotting. The antigenic 20 kDa protein was in-gel digested and identified the antigenome by LTQ mass spectrometer and peptide match fingerprinting, which were MPB64, MPB70, MPB83, Fas, Smc, Nrp, RpoC, Transposase, LeuA, and MtbE. The 20 kDa protein exhibited the highest antigenicity to bTB positive cattle in ELISA and would be useful for bTB serological diagnosis.

RNA-seq data for olive flounder (Paralichthys olivaceus) according to water temperature.

We provide raw data from a transcriptomic analysis of olive flounder in response to changes in water temperature. At the time of this analysis, the olive flounder genome was not yet available in China, and there were no related references. Therefore, assembly was carried out using the de novo method to reveal the entire nucleotide sequence based on the nucleotide sequence information of the sequenced reads. The functions of expressed genes based on Gene Ontology analysis are also categorized and presented.

Expression analysis data of T-cell surface antigen CD2 gene from rock bream (Oplegnathus fasciatus).

This data article reports the expression level of T-cell surface antigen CD2 gene in organs from normal rock bream through quantitative real-time PCR. We also report the expression level of CD2 gene when anthropogenic infection with bacterial or viral pathogens was induced. The expression pattern of CD2 gene in normal rock bream was proved to be highly expressed in hematopoietic cells involved in the production and development of peripheral blood leukocytes (PBLs) and immune cells. It also proved that it maintains high expression for normal immunity in gills, skin, and intestines exposed directly to the environment. The expression pattern of CD2 gene in pathogenic infection has proven that CD2 is a factor involved in immunity. These data are considered to be a basic study of teleost immune system and will contribute to the study of fish blood cells.