Search

Agrochemicals containing antibiotics are authorized to manage fire blight that has been occurring in Korea since 2015. The minimum inhibitory concentration (MIC) of each antibiotic against Erwinia amylovora, the causal pathogen of fire blight, has increased over the years due to the pathogen’s frequent exposure to antibiotics, indicating the necessity to prepare for the emergence of antibiotic resistance. In this study, E. amylovora was exposed to stepwise increasing concentrations of eight different agrochemicals, each containing single or mixed antibiotics, and gene mutation and changes in MIC were assessed. Streptomycin and oxolinic acid induced an amino acid substitution in RpsL and GyrA, respectively, resulting in a rapid increase in MIC. Oxytetracycline initially induced amino acid substitutions or frameshifts in AcrR, followed by substitutions of 30S small ribosomal protein subunit S10 or AcrB, further increasing MIC. E. amylovora acquired resistance in the order of oxolinic acid, streptomycin, and oxytetracycline at varying exposure frequencies. Resistance acquisition was slower against agrochemicals containing mixed antibiotics than those with single antibiotics. However, gene mutations conferring antibiotic resistance emerged sequentially to both antibiotics in the mixed formulations. Results suggested that frequent application of mixed antibiotics could lead to the emergence of multidrug-resistant E. amylovora isolates. This study provided essential insights into preventing the emergence of antibiotic-resistant E. amylovora and understanding the underlying mechanisms of resistance acquisition.

Abstract Bacteria perceive light signals via photoreceptors and modulate many physiological and genetic processes. The impacts played by light, oxygen, or voltage (LOV) and blue light (BL) photosensory proteins on the virulence-related traits of plant bacterial pathogens are diverse and complex. In this study, we identified LOV protein (Pc-LOV1) from Pseudomonas cichorii JBC1 (PcJBC1) and characterized its function using LOV1-deficient mutant (JBC1Δlov1). In the dark state, the recombinant Pc-LOV1 protein showed an absorption band in UV-A region with a double peak at 340 nm and 365 nm, and within the blue-region, it exhibited a main absorption at 448 nm along with two shoulder peaks at 425 nm and 475 nm, which is a typical feature of oxidized flavin within LOV domain. The adduct-state lifetime (τrec) of Pc-LOV1 was 67.03 ± 4.34 min at 25 °C. BL negatively influenced the virulence of PcJBC1 and the virulence of JBC1Δlov1 increased irrespective of BL, indicating that Pc-LOV1 negatively regulates PcJBC1 virulence. Pc-LOV1 and BL positively regulated traits relevant to colonization on plant surface, such as adhesion to the plant tissue and biofilm formation. In contrast, swarming motility, exopolysaccharide production, and siderophore synthesis were negatively controlled. Gene expression supported the modulation of bacterial features by Pc-LOV1. Overall, our results suggest that the LOV photosensory system plays crucial roles in the adaptive responses and virulence of the bacterial pathogen PcJBC1. The roles of other photoreceptors, sensing of other wavelengths, and signal networking require further investigation.

Erwinia amylovora, a causal pathogen of fire blight, has been continuously inducing damage to the apple and pear trees in South Korea since 2015. Farmers apply antibiotics during blooming season to prevent the fire blight. However, continuous use of antibiotics can induce the emergence of resistant bacteria, which consequently reduces control efficacy. In this study, we assessed the minimal inhibitory concentration (MIC) of streptomycin, using a total of 361 E. amylovora isolates that were collected from the six provinces of South Korea from 2019 to 2023. As a result, the MIC of streptomycin ranged from 0.5 to 4 µg/ml and the strA-strB genes were not identified from the isolates. The MIC was higher in the isolates from Gyeonggi-do, Gangwon-do, and Chungcheongbuk-do compared to those from other three provinces. These results may bring broad attention to the use of streptomycin and aid in developing a management protocol for the occurrence of fire blight in South Korea.

Background/Aims Epidermal growth factor receptor (EGFR) mutation is important in determining the treatment strategy for advanced lung cancer patients with malignant pleural effusion (MPE). Contrary to serum carcinoembryonic antigen (S-CEA) levels, the associations between pleural fluid CEA (PF-CEA) levels and EGFR mutation status as well as between PF-CEA levels and treatment efficacy have rarely been investigated in lung adenocarcinoma patients with MPE. Methods This retrospective study enrolled lung adenocarcinoma patients with MPE and available PF-CEA levels and EGFR mutation results. The patients were categorized based on PF-CEA levels: < 10 ng/mL, 10–100 ng/mL, 100–500 ng/mL, and ≥ 500 ng/mL. The association between PF-CEA levels and EGFR mutation status as well as their therapeutic impact on overall survival was compared among the four groups. Results This study included 188 patients. PF-CEA level was found to be an independent predictor of EGFR mutation but not S-CEA level. The EGFR mutation rates were higher as the PF-CEA levels increased, regardless of cytology results or sample types. Among EGFR-mutant lung adenocarcinoma patients receiving EGFR-tyrosine kinase inhibitor (TKI) treatment, those with high PF-CEA levels had significantly better survival outcomes than those with low PF-CEA levels. Conclusion High PF-CEA levels were associated with high EGFR mutation rate and may lead to a favorable clinical outcome of EGFR-TKI treatment in EGFR-mutant lung adenocarcinoma patients with MPE. These findings highlight the importance of actively investigating EGFR mutation detection in patients with suspected MPE and elevated PF-CEA levels despite negative cytology results.

Symbiotic microbes are essential for developing and growing Gastrodia elata, an achlorophyllous orchid of high medicinal value. Recently, the cultivation of G. elata in greenhouses has been adopted in Korea to produce mature tubers in a short time. However, no studies have been conducted on the microbial community structure of G. elata cultivated in greenhouse environments. Therefore, we analyzed the temporal features of bacterial and fungal communities in the rhizosphere of G. elata at the juvenile [JT; 2 months after sowing (MAS)], young (YT; 6 MAS), and mature (MT; 11 MAS) tuber stages using culture-dependent and high-throughput sequencing technology. The richness and diversity of the bacterial and fungal communities decreased with tuber growth of G. elata. The symbiotic fungi Mycena sp. and Armillaria sp. as well as tuber extract inhibited the growth of various soil-inhabiting fungal and bacterial strains, indicating that G. elata and its symbiotic fungi play important roles in the selection of rhizosphere microbes. Mortierella rishikesha was the most abundant fungal species in the rhizosphere. We also identified the microorganisms potentially beneficial for G. elata development during greenhouse cultivation. Tubers and symbiotic fungi actively exert selective pressure on rhizosphere microbes, influencing the diversity and abundance of bacterial and fungal communities as G. elata grows. This study is a first report on the temporal microbial community structure of G. elata cultivated in greenhouse. The results on the associated microbiome of G. elata will help understand their beneficial interactions with G. elata and contribute to improvement in cultivation.

Background Stenotrophomonas maltophilia has been increasingly recognized as an opportunistic pathogen associated with high morbidity and mortality. Data on the prognostic factors associated with S. maltophilia pneumonia in patients admitted to intensive care unit (ICU) are lacking. Methods We conducted a retrospective analysis of data from 117 patients with S. maltophilia pneumonia admitted to the ICUs of two tertiary referral hospitals in South Korea between January 2011 and December 2022. To assess risk factors associated with in-hospital mortality, multivariable logistic regression analyses were performed. Results The median age of the study population was 71 years. Ventilator-associated pneumonia was 76.1% of cases, and the median length of ICU stay before the first isolation of S. maltophilia was 15 days. The overall in-hospital mortality rate was 82.1%, and factors independently associated with mortality were age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.00–1.09; P=0.046), Sequential Organ Failure Assessment (SOFA) score (OR, 1.21; 95%; CI, 1.02–1.43; P=0.025), corticosteroid use (OR, 4.19; 95% CI, 1.26–13.91; P=0.019), and polymicrobial infection (OR, 0.22; P=0.009). However, the impact of appropriate antibiotic therapy on mortality was insignificant. In a subgroup of patients who received appropriate antibiotic therapy (n=58), antibiotic treatment modality-related variables, including combination or empirical therapy, also showed no significant association with survival. Conclusions Patients with S. maltophilia pneumonia in ICU have high mortality rates. Older age, higher SOFA score, and corticosteroid use were independently associated with increased in-hospital mortality, whereas polymicrobial infection was associated with lower mortality. The effect of appropriate antibiotic therapy on prognosis was insignificant.

Abstract Background Necroptosis is a regulated inflammatory cell death which plays a significant role in cancer development and progression. In this study, we evaluated whether genetic variants in key regulators of necroptosis may affect survival outcome of non‐small cell lung cancer (NSCLC) patients after surgical resection. Methods A total of 674 patients who underwent curative surgery were included. Fifteen genetic variants in key regulators of necroptosis (RIPK1, RIPK3, and MLKL) were selected. The association of these variants with survival outcomes was evaluated. Results Two variants, RIPK1 rs17548629C > T and MLKL rs877375G > C, were associated with better overall survival and disease‐free survival in multivariate analyses. When the patients were divided according to histology, the associations were significant only in adenocarcinoma, but not in squamous cell carcinoma. RIPK1 rs17548629 C‐to‐T change was associated with significantly increased luciferase activity by modulating the binding of miR‐642a. Promoter assays showed a significantly increased promoter activity in MLKL rs877375C allele compared to G allele. Consistently, the mRNA expression level of RIPK1 and MLKL showed significant positive correlation with RIPK1 rs17548629C‐to‐T and MLKL rs877375G‐to‐C changes. Conclusion Two genetic variants in key regulators in necroptosis, RIPK1 rs17548629C > T and MLKL rs877375G > C, may be used as biomarkers to predict survival outcomes in surgically resected NSCLC patients.

Abstract Microbes influence plant growth and fitness. However, the structure and function of microbiomes associated with rare and endemic plants remain underexplored. To investigate the bacterial community structure of Ulleung-sanmaneul (U-SMN), an endemic plant in Korea, samples were collected from natural and cultivated habitats, and their 16S rDNA was sequenced. The root bacterial community structure differed from those of bulk soil and rhizosphere in both habitats. Endogenous bacteria in cultivated plants were less diverse than wild plants, but Luteibacter rhizovicinus, Pseudomonas fulva, and Sphingomonas pruni were shared. Co-inoculation of Pseudoxanthomonas sp. JBCE485 and Variovorax paradoxus JBCE486 promoted growth and induced salt stress resistance in Arabidopsis and chive. Changes in growth promotion and phenotypes of plants by co-inoculation were mediated by increased auxin production. Each strain colonized the roots without niche competition. The results indicated that host selectivity was influential than environmental factors in formulating endophytic bacterial composition, and domestication simplified the bacterial community diversity. Our results will contribute to the growth and maintenance of endemic U-SMN plants.

Abstract This study was conducted to investigate the relationship between genetic variants in LKB1/AMPK/mTOR pathway and treatment outcomes of patients with non‐small cell lung cancer (NSCLC) treated with chemotherapy. A total of 379 patients with NSCLC who underwent first‐line paclitaxel‐cisplatin chemotherapy was enrolled. The associations between 19 single nucleotide variants (SNVs) in the LKB1/AMPK/mTOR pathway and the chemotherapy response and overall survival (OS) were analyzed. Among the SNVs analyzed, AKT1 rs2494750G>C and TSC1 rs2809244C>A were associated with clinical outcomes after chemotherapy in multivariate analyses. The AKT1 rs2494750G>C was significantly associated with a better response to chemotherapy (adjusted odds ratio [aOR]: 1.92, 95% confidence interval [CI]: 1.02–3.62, p = 0.04). The TSC1 rs2809244C>A were significantly associated with better OS (adjusted hazard ratio [aHR]: 0.79, 95% CI: 0.62–0.99, p = 0.04). When stratified by tumor histology, AKT1 rs2494750G>C exhibited a significant association with the chemotherapy response only in adenocarcinoma and TSC1 rs2809244C>A was also significantly associated with OS only in adenocarcinoma. This result suggests that the AKT1 rs2494750G>C and TSC1 rs2809244 C>A may be useful for predicting the clinical outcome of first‐line paclitaxel‐cisplatin chemotherapy in NSCLC.

Fire blight caused by Erwinia amylovora (Ea) is a devastating disease in apple and pear trees. Oxolinic acid (OA), a quinolone family antibiotic that inhibits DNA gyrase, has been employed to control fire blight in South Korea since 2015. The continuous use of this bactericide has resulted in the emergence of OA-resistant strains in bacterial pathogens in other countries. To investigate the occurrence of OA-resistant Ea strains in South Korea, we collected a total of 516 Ea isolates from diseased apple and pear trees in 2020–2021 and assessed their sensitivities to OA. We found that all isolates were susceptible to OA. To explore the possibility of emerging OA-resistant Ea by continuous application of OA, we exposed Ea stains to a range of OA concentrations and constructed OA-resistant mutant strains. Resistance was associated with mutations in the GyrA at codons 81 and 83, which result in glycine to cysteine and serine to arginine amino acid substitutions, respectively. The in vitro growth of the mutants in nutrient media and their virulence in immature apple fruits were lower than those of wild-type. Our results suggest that OA-resistance decreases the fitness of Ea. Future work should clarify the mechanisms by which OA-resistance decreases virulence of this plant pathogen. Continuous monitoring of OA-resistance in Ea is required to maintain the efficacy of this potent bactericide.

Bromodomain and extraterminal domain (BET) proteins are epigenetic readers that regulate gene expression. We investigated whether variants in BET genes are associated with survival outcomes for lung cancer. To do this, the associations between 77 variants in BET family genes and survival outcomes were analyzed in 773 non‐small‐cell lung cancer (NSCLC) patients who underwent surgery (349 and 424 patients in the discovery and validation cohorts, respectively). We found that six variants were significantly associated with overall survival (OS) in the discovery cohort, and one variant (rs2506711C>T) was replicated in the validation cohort. BRD3 rs2506711C>T is located in the repressed area and has a strong linkage disequilibrium with rs2427964C>T in the promoter region. BRD3 rs2427964C>T was significantly associated with worse OS in the discovery cohort, validation cohort, and combined analysis. In a luciferase assay, promoter activity in the BRD3 rs2427964 T allele was significantly higher than that in the BRD3 rs2427964 C allele, which selectively bound with the transcriptional repressor SIN3A. Knockdown of BRD3 with BRD3‐specific siRNA decreased the proliferation and migration of lung cancer cells while also increasing the rate of apoptosis. These results suggest that BRD3 rs2427964C>T increases BRD3 expression through increased promoter activity, which is associated with poor prognosis for lung cancer.

Abstract Elucidating underlying mechanisms of biocontrol agents (BCAs) could aid in selecting potent BCAs and increasing their biocontrol efficacy. Nutrient competition is an important biocontrol mechanism; however, essential nutrient sources, and contributing genes for nutrient competition still remain to be explored. Pseudomonas putida JBC17 (JBC17WT) suppressed green mold in satsuma mandarins by inhibiting conidial germination of Penicillium digitatum via nutrient competition. To analyze genes essential for biocontrol performance of JBC17WT, we generated a transposon (Tn)-mediated mutant library and selected mutants with the ability to suppress conidial germination. Several mutants in the genes of flagella-formation, including fliR, fliH, and flgG, increased biocontrol performance and enhanced inhibition of conidial germination. They lost swimming motility, exhibited increased growth and rapid carbon and nitrogen utilization than the wild type under nutrient-poor conditions. The nutrient competition assay using polytetrafluoroethylene cylinders revealed that conidial germination was inhibited by nutrient absorption under nutrient-poor conditions. In addition, genes, including amidohydrolase (ytcJ), tonB-dependent receptor (cirA), argininosuccinate synthase (argG), D-3-phosphoglycerate dehydrogenase (serA), and chaperone protein (dnaJ), were involved in the inhibition of conidial germination. The results of this study indicate that rapid and continuous absorption of nutrients by JBC17WT restrict nutrient availability for conidial germination on nutrient-limited fruit surfaces, thereby decreasing the chances of fungal spores infecting fruits. The high-throughput analysis of Tn mutants of this study highlighted the importance of nutrient competition and the genes that influence biocontrol ability, which contributes to the development of biocontrol applications.

Abstract We investigated the association between genetic variants in the histone modification regions and the prognosis of lung adenocarcinoma after curative surgery. Potentially functional SNPs were selected using integrated analysis of ChIP-seq and RNA-seq. The SNPs were analyzed in a discovery set (n = 166) and a validation set (n = 238). The associations of the SNPs with overall survival (OS) and disease-free survival (DFS) were analyzed. A total of 279 SNPs were selected for genotyping. Among these, CAPN1 rs17583C>T was significantly associated with better OS and DFS (P = 0.001 and P = 0.007, respectively), and LINC00959 rs4751162A>G was significantly associated with worse DFS (P = 0.008). Luciferase assays showed a significantly lower promoter activity of CAPN1 in the rs17583 T allele than C allele (P = 0.008), and consistently the CT + TT genotypes had significantly lower CAPN1 expression than CC genotype (P = 0.01) in clinical samples. The rs4751162 G allele had higher promoter activity of GLRX3 than A allele (P = 0.05). The motif analyses and ChIP-qPCR confirmed that the variants are located in the active promoter/enhancer regions where transcription factor binding occurs. This study showed that genetic variants in the histone modification regions could predict the prognosis of lung adenocarcinoma after surgery.

Pseudomonas cichorii secretes effectors that suppress defense mechanisms in host plants. However, the function of these effectors, including avirulence protein E1 (AvrE1), in the pathogenicity of P. cichorii, remains unexplored. In this study, to investigate the function of avrE1 in P. cichorii JBC1 (PcJBC1), we created an avrE1-deficient mutant (JBC1ΔavrE1) using CRISPR/Cas9. The disease severity caused by JBC1ΔavrE1 in tomato plants significantly decreased by reducing water soaking during early infection stage, as evidenced by the electrolyte leakage in infected leaves. The disease symptoms caused by JBC1ΔavrE1 in the cabbage midrib were light-brown spots compared to the dark-colored ones caused by PcJBC1, which indicates the role of AvrE1 in cell lysis. The avrE1-deficient mutant failed to elicit cell death in non-host tobacco plants. Disease severity and cell death caused by JBC1ΔavrE1 in host and non-host plants were restored through heterologous complementation with avrE1 from Pseudomonas syringae pv. tomato DC3000 (PstDC3000). Overall, our results indicate that avrE1 contributes to cell death during early infection, which consequently increases disease development in host plants. The roles of PcJBC1 AvrE1 in host cells remain to be elucidated.

Seed endophytes are of interest because they are believed to affect seed quality, and ultimately, plant growth and fitness. A comprehensive understanding of the assembly of the seed microbiome during seed development and maturation, the fate of microbes during storage, and the migration of microbes during seedling growth are still lacking. In this study, to understand the assembly and fate of endogenous bacteria in rice seeds from the ripening stage to the storage and seedling stages, we employed culture-dependent and metagenomic analyses. Bacterial communities in rice seeds were composed of a few dominant taxa that were introduced at the milky and dough stages, and they persisted during seed maturation. The culturable bacterial population gradually increased during the ripening stage, whereas there was a gradual decrease during storage. Bacteria that persisted during storage proliferated after imbibition and were distributed and established in the shoots and roots of rice seedlings. The storage temperature influenced the abundance of bacteria, which consequently changed the bacterial composition in the shoots and roots of seedlings. Pantoea, Pseudomonas, and Allorhizobium were consistently abundant from seed development to the germination stage. Some endogenous bacterial strains significantly promoted the growth of Arabidopsis and rice plants. Overall, our results indicate that rice seeds are colonized by a few bacterial taxa during seed development, and their relative abundance fluctuates during storage and contributes significantly to the establishment of endophytes in the stems and roots of rice plants. The selected bacterial isolates can be used to improve the growth and health of rice plants. To the best of our knowledge, this is the first study to reveal the dynamics of bacterial populations during storage of rice seeds at different temperatures. The temporal dynamics of the bacterial community during seed storage provide clues for the manipulation of endogenous bacteria in rice plants.

Abstract This study was conducted to investigate the impact of genetic variants of immune checkpoint genes on the treatment outcome in small cell lung cancer (SCLC). In the present study, 261 platinum doublet-treated SCLC patients were enrolled. A total of 96 polymorphisms in 33 immune checkpoint-related genes were selected, and their association with chemotherapy response and survival outcomes were analyzed. Among the polymorphisms studied, CD155 rs1058402G > A (Ala67Thr, A67T) and CD226 rs763361C > T (Gly307Ser, G307S) were significantly associated with SCLC treatment outcome. The rs1058402G > A had a worse chemotherapy response and overall survival (under a dominant model, adjusted odds ratio [aOR] = 0.52, 95% confidence interval [CI] = 0.27–0.99, P = 0.05; adjusted hazard ratio [aHR] = 1.55, 95% CI = 1.12–2.14, P = 0.01, respectively). The rs763361C > T had better chemotherapy response and overall survival (under a dominant model, aOR = 2.03, 95% CI = 1.10–3.75, P = 0.02; aHR = 0.69, 95% CI = 0.51–0.94, P = 0.02, respectively). When the rs1058402GA/AA and rs763361CC genotypes were combined, the chemotherapy response and overall survival were significantly decreased as the number of bad genotypes increased (aOR = 0.52, 95% CI = 0.33–0.81, Ptrend = 0.004; aHR = 1.48, 95% CI = 1.19–1.84, Ptrend = 4 × 10−4, respectively). The 3-D structural model showed that CD155 A67T created a new hydrogen bond and structural change on CD155. These changes resulted in extending the distance and losing the hydrogen bonds between CD155 and CD226, thus weakening CD155/CD226 binding activity. In conclusion, CD155 rs1058402G > A and CD226 rs763361C > T may be useful for predicting the clinical outcomes of SCLC patients after chemotherapy.

An understanding of the contribution of secondary metabolites (SMs) to the antagonistic and biocontrol activities of bacterial biocontrol agents serves to improve biocontrol potential of the strain. In this study, to evaluate the contribution of each SM produced by Pseudomonas fluorescens NBC275 (Pf275) to its antifungal and biocontrol activity, we combined in silico analysis of the genome with our previous study of transposon (Tn) mutants. Thirteen Tn mutants, which belonged to 6 biosynthetic gene clusters (BGCs) of a total 14 BGCs predicted by the antiSMASH tool were identified by the reduction of antifungal activity. The biocontrol performance of Pf275 was significantly dependent on 2,4-diacetylphloroglucinol and pyoverdine. The clusters that encode for arylpolyene and an unidentified small linear lipopeptide influenced antifungal and biocontrol activities. To our knowledge, our study identified the contribution of SMs, such as a small linear lipopeptide and arylpolyene, to biocontrol efficacy for the first time

Deltex‐1 (DTX1) is a negative regulator of the Notch signaling pathway. Here, we investigated the clinical effect of DTX1 rs1732786A > G, which is associated with better prognosis in patients with early‐stage non‐small cell lung cancer (NSCLC), in 261 patients with small cell lung cancer (SCLC). DTX1 rs1732786A > G was associated with a significantly worse chemotherapy response and lower overall survival in the codominant model (odds ratio = 0.42, 95% confidence interval [CI]: 0.26–0.66, P = 2 × 10−4; hazard ratio = 1.47, 95% CI: 1.17–1.84, P = 0.001, respectively). An in vitro luciferase assay was performed, and the 1732786G allele demonstrated significantly higher promoter activity than the 1732786A allele (P = 2 × 10−7). In summary, DTX1 rs1732786A > G was associated with poor prognosis in patients with SCLC as opposed to patients with NSCLC. Key points Significant findings of the study DTX1 rs1732786A > G was associated with better prognosis in patients with early‐stage non‐small cell lung cancer (NSCLC) in our previous study. What this study adds DTX1 rs1732786A > G was associated with a significantly worse chemotherapy response and lower overall survival in small cell lung cancer (SCLC).

BackgroundCoronavirus disease 2019 (COVID-19) is a global pandemic that had affected more than eight million people worldwide by June 2020. Given the importance of the presence of diabetes mellitus (DM) for host immunity, we retrospectively evaluated the clinical characteristics and outcomes of moderate-to-severe COVID-19 in patients with diabetes.MethodsWe conducted a multi-center observational study of 1,082 adult inpatients (aged ≥18 years) who were admitted to one of five university hospitals in Daegu because of the severity of their COVID-19-related disease. The demographic, laboratory, and radiologic findings, and the mortality, prevalence of severe disease, and duration of quarantine were compared between patients with and without DM. In addition, 1:1 propensity score (PS)-matching was conducted with the DM group.ResultsCompared with the non-DM group (n=847), patients with DM (n=235) were older, exhibited higher mortality, and required more intensive care. Even after PS-matching, patients with DM exhibited more severe disease, and DM remained a prognostic factor for higher mortality (hazard ratio, 2.40; 95% confidence interval, 1.38 to 4.15). Subgroup analysis revealed that the presence of DM was associated with higher mortality, especially in older people (≥70 years old). Prior use of a dipeptidyl peptidase-4 inhibitor or a renin-angiotensin system inhibitor did not affect mortality or the clinical severity of the disease.ConclusionDM is a significant risk factor for COVID-19 severity and mortality. Our findings imply that COVID-19 patients with DM, especially if elderly, require special attention and prompt intensive care.

Background Achaete‐scute homolog 1 (ASCL1) is a basic helix‐loop‐helix transcription factor and is essential in the differentiation of neuroendocrine cells and neural tissues. ASCL1 is frequently overexpressed in small cell lung cancer (SCLC) and plays a crucial role in the pathogenesis of SCLC. Methods This study was conducted to identify the association between single nucleotide polymorphisms (SNPs) in ASCL1 target genes and clinical outcomes of patients with SCLC after chemotherapy. A total of 261 patients diagnosed with SCLC were enrolled in this study. The association between 103 SNPs in 58 ASCL1 target genes and the response to chemotherapy and survival of patients with SCLC were analyzed. Results Among the 103 SNPs, 10 SNPs were significantly associated with the response to chemotherapy, and 19 SNPs were associated with OS in multivariate analyses. Among these, Dopa Decarboxylase (DDC) rs12666409A>T was significantly associated with both a worse response to chemotherapy and worse OS (adjusted odds ratio [aOR] = 0.40, 95% CI = 0.18–0.90, P = 0.03; adjusted hazard ratio [aHR] = 1.52, 95% CI = 1.10–2.10, P = 0.01, respectively, under a dominant model). In a stage‐stratified analysis, the association was significant only in the extensive disease subgroup (aOR = 0.19, 95% CI = 0.06–0.60, P = 0.01; aHR = 1.73, 95% CI = 1.16–2.56, P = 0.01, respectively, under a dominant model), but not in the limited disease subgroup. Conclusion The results of our study suggest that DDC rs12666409A>T may be useful markers for predicting the clinical outcomes of patients with SCLC undergoing chemotherapy.

Microbes associated with plants significantly influence the development and health of the plants. The diversity and function of microbiomes associated with the long-sepal Donggang pasque-flower (DPF) plant, an endemic and endangered species in karst ecosystems, remain unexplored. In this study, we investigated the features of bacterial communities associated with the rhizosphere and roots of DPF plants and their functions in plant growth promotion. The DPF plants were collected from natural and cultivated habitats, and their 16S rDNA was sequenced to assess the bacterial community structures. The bacterial microbiota was more diverse in wild than in cultivated plants. The core bacterial microbiota commonly functioned as endophytes in both wild and cultivated DPF plants, although there were some differences. The identified bacterial strains benefited plants through nitrogen fixation, phosphate solubilization, or phytohormone production, inducing measurable growth differences in Arabidopsis thaliana. To the best of our knowledge, this study is the first to report the bacterial community structures associated with the rhizosphere soil and roots of DPF plants in karst ecosystems. The bacterial strains isolated in this study could be used to aid sustainable growth and restoration of rare plants in karst ecosystems. Our systematic research on the microbiomes associated with these endangered plants will contribute to their conservation as well as development of better cultivation.

This study was conducted to investigate the associations between polymorphisms of genes involved in the LKB1 pathway and the prognosis of patients with non‐small cell lung cancer (NSCLC) after surgical resection. Twenty‐three single nucleotide polymorphisms (SNPs) in the LKB1 pathway were investigated in 782 patients with NSCLC who underwent curative surgery. The association of SNPs with overall survival (OS) and disease‐free survival (DFS) were analyzed. Among the 23 SNPs investigated, TSC2 rs30259G > A was associated with significantly worse OS and DFS (adjusted hazard ratio for OS 1.88, 95% confidence interval 1.21–2.91, P = 0.005; adjusted hazard ratio for DFS 1.65, 95% confidence interval 1.15–2.38, P = 0.01, under codominant models, respectively). Subgroup analysis showed that SNPs were significantly associated with survival outcomes in squamous cell carcinoma, ever‐smokers, and stage I, but not in adenocarcinoma, never‐smokers, and stage II–IIIA. The results suggest that TSC2 rs30259G > A may be useful to predict prognosis in patients with NSCLC, especially squamous cell carcinoma, after curative surgery.

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of white-rot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.

As part of ongoing systematic research into the discovery of bioactive secondary metabolites with novel structures from Korean wild mushrooms, we investigated secondary metabolites from a poisonous mushroom, Omphalotus japonicus (Kawam.) Kirchm. & O. K. Mill. belonging to the family Marasmiaceae, which causes nausea and vomiting after consumption. The methanolic extract of O. japonicus fruiting bodies was subjected to the fractionation by solvent partition, and the CH2Cl2 fraction was analyzed for the isolation of bioactive compounds, aided by an untargeted liquid chromatography mass spectrometry (LC–MS)-based analysis. Through chemical analysis, five fatty acid derivatives (1–5), including two new fatty acid derivatives, omphalotols A and B (1 and 2), were isolated from the CH2Cl2 fraction, and the chemical structures of the new compounds were determined using 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high resolution electrospray ionization mass spectrometry (HR-ESIMS), as well as fragmentation patterns in MS/MS data and chemical reactions followed by the application of Snatzke’s method and competing enantioselective acylation (CEA). In the anti-Helicobacter pylori activity test, compound 1 showed moderate antibacterial activity against H. pylori strain 51 with 27.4% inhibition, comparable to that of quercetin as a positive control. Specifically, compound 3 exhibited the most significant antibacterial activity against H. pylori strain 51, with MIC50 and MIC90 values of 9 and 20 μM, respectively, which is stronger inhibitory activity than that of another positive control, metronidazole (MIC50 = 17 μM and MIC90 = 46 μM). These findings suggested the experimental evidence that the compound 3, an α,β-unsaturated ketone derivative, could be used as a moiety in the development of novel antibiotics against H. pylori.

Maintenance of a beneficial microbial community, especially in the rhizosphere, is indispensable for plant growth and agricultural sustainability. In this sense, plant growth-promoting rhizobacteria (PGPR) have been extensively studied for their role in plant growth promotion and disease resistance. However, the impact of introducing PGPR strains into rhizosphere microbial communities is still underexplored. We previously found that the Proteus vulgaris JBLS202 strain (JBLS202) promoted growth of Kimchi cabbage and altered the relative abundance of total bacteria and Pseudomonas spp. in the treated rhizosphere. To extend these findings, we used pyrosequencing to analyze the changes in bacterial communities in the rhizosphere of Kimchi cabbage after introduction of JBLS202. The alterations were also evaluated by taxon-specific real-time PCR (qPCR). The pyrosequencing data revealed an increase in total bacteria abundance, including specific groups such as Proteobacteria, Acidobacteria, and Actinobacteria, in the treated rhizosphere. Time-course qPCR analysis confirmed the increase in the abundance of Acidobacteria, Actinobacteria, Alphaproteobacteria, and Betaproteobacteria. Furthermore, genes involved in nitrogen cycling were upregulated by JBLS202 treatment indicating changes in ecological function of the rhizosphere soil. Overall, these results indicate that introduction of JBLS202 alters both the composition and function of the rhizosphere bacterial community, which can have direct and indirect effects on plant growth. Therefore, we propose that long-term changes in bacterial composition and community-level function need to be considered for practical use of PGPRs.

Phaseolus multiflorus var. albus (Leguminosae), commonly known as “white kidney bean”, is a twining perennial vine whose fruit has been used as a popular food worldwide owing to its high nutritional content, in terms of proteins, carbohydrates, fats, and vitamins. As part of our ongoing study to investigate novel bioactive components from various natural resources, a phytochemical investigation of the extract of P. multiflorus var. albus fruits resulted in the isolation of three phenolic compounds (1–3) and one dipeptide (4). The chemical structures of the compounds (1–4) were determined through 1D and 2D nuclear magnetic resonance spectroscopy and high-resolution-liquid chromatography–mass spectrometry; they were identified as denatonium (1), trans-ferulic acid ethyl ester (2), eugenin (3), and α-L-glutamyl-L-Leucine (4). Intriguingly, denatonium (1) is known to be the most bitter chemical compound. To the best of our knowledge, denatonium (1) was identified from natural sources for the first time, and compounds 2–4 were reported for the first time from P. multiflorus var. albus in this study; however, compound 2 turned out to be an artifact produced by an extraction with ethanol. The isolated compounds 1–4 were tested for their regulatory effects on the differentiation between osteogenesis and adipogenesis of mesenchymal stem cells (MSCs). Compound 4 slightly suppressed the adipogenic differentiation of MSCs, and compounds 1 and 4 stimulated osteogenic differentiation, unlike the negative control. These findings provide experimental evidence that compounds 1 and 4 may induce the osteogenesis of MSCs and activate bone formation.

BackgroundDiabetic cardiac autonomic neuropathy (CAN) is one of the important complications of diabetes. It is characterized by reduced heart rate variability (HRV).MethodsIn this randomized, double-blind, placebo-controlled, multicenter trial, 75 patients were randomly assigned to one of two groups. One group (n=41) received α-lipoic acid (ALA) at an oral dose of 600 mg/day for the first 12 weeks and then 1,200 mg/day for the next 12 weeks. The other group (n=34) received placebo treatment for 24 weeks. CAN was assessed by measuring HRVs in people with diabetes.ResultsMost of the baseline measures for HRVs were similar between the ALA and placebo groups. Although there were no statistically significant HRV changes in the ALA group compared to the placebo group after 24 weeks of trial, we found a positive tendency in some of the HRV parameters of the ALA group. The standard deviations of normal-to-normal RR intervals in the standing position increased by 1.87 ms in the ALA group but decreased by −3.97 ms in the placebo group (P=0.06). The power spectrum of the low frequency (LF) band in the standing position increased by 15.77 ms2 in the ALA group, whereas it declined by −15.04 ms2 in the placebo group (P=0.08). The high frequency/LF ratio in the upright position increased by 0.35 in the ALA group, whereas it declined by −0.42 in the placebo group (P=0.06). There were no differences between the two groups regarding rates of adverse events.ConclusionAlthough a slight improvement tendency was seen in HRV in the ALA group, there were no statistically significant HRV changes in the ALA group compared to the placebo group after 24 weeks of trial. However, the high oral dose of ALA was well-tolerated.

Background : Dapagliflozin, a sodium-glucose cotransporter-2 inhibitor, reduces hyperglycemia and body weight by inhibiting renal glucose reabsorption. However, only a few studies have demonstrated efficacy of dapagliflozin for type 2 diabetic patients in Korea. We evaluated the efficacy and safety of dapagliflozin for Korean type 2 diabetes patients. Methods : This is a retrospective study that included data from 61 patients who received 12 months of dapagliflozin therapy and who visited a single medical center between January 2015 and July 2016. Patients were separated into three groups: dual combination of dapagliflozin and metformin, triple combination of dapagliflozin and metformin with sulfonylurea, or dipeptidyl peptidase IV inhibitors, and quadriple combination of dapagliflozin, metformin, and sulfonylurea with dipeptidyl peptidase IV inhibitors. Patients who achieved ≥5% body weight reduction were classified as responders, and those who achieved

Hippophae rhamnoides L. (Elaeagnaceae), commonly known as “Sea buckthorn” and “Vitamin tree”, is a spiny deciduous shrub whose fruit is known for its nutritional composition, such as vitamin C, and is consumed as a dietary supplement worldwide. As part of our ongoing efforts to identify structurally new and bioactive constituents from natural resources, the phytochemical investigation of the extract of H. rhamnoides fruits led to the isolation of one malate derivative (1), five citrate derivatives (2–6), and one quinate derivative (7). The structures of the isolated compounds were elucidated by analysis of 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data and high-resolution electrospray ionization (HR-ESI) liquid chromatography–mass spectrometry (LC/MS) data. Three of the citrate derivatives were identified as new compounds: (S)-1-butyl-5-methyl citrate (3), (S)-1-butyl-1′-methyl citrate (4), and (S)-1-methyl-1′-butyl citrate (6), which turned out to be isolation artifacts. The absolute configurations of the new compounds were established by quantum chemical electronic circular dichroism (ECD) calculation, which is an informative tool for verifying the absolute configuration of organic acid derivatives. The isolated compounds 1–7 were evaluated for their stimulatory effects on osteogenesis. Compounds 1, 3, 4, 6, and 7 stimulated osteogenic differentiation up to 1.4 fold, compared to the negative control. These findings provide experimental evidence that active compounds 1, 3, 4, 6, and 7 induce the osteogenesis of mesenchymal stem cells and activate bone formation.

Pathogen infection in plants induces complex responses ranging from gene expression to metabolic processes in infected plants. In spite of many studies on biotic stress-related changes in host plants, little is known about the metabolic and phenotypic responses of the host plants to Pseudomonas cichorii infection based on image-based analysis. To investigate alterations in tomato plants according to disease severity, we inoculated plants with different cell densities of P. cichorii using dipping and syringe infiltration methods. High-dose inocula (≥ 10⁶ cfu/ml) induced evident necrotic lesions within one day that corresponded to bacterial growth in the infected tissues. Among the chlorophyll fluorescence parameters analyzed, changes in quantum yield of PSII (ΦPSII) and non-photochemical quenching (NPQ) preceded the appearance of visible symptoms, but maximum quantum efficiency of PSII (Fv/Fm) was altered well after symptom development. Visible/near infrared and chlorophyll fluorescence hyperspectral images detected changes before symptom appearance at low-density inoculation. The results of this study indicate that the P. cichorii infection severity can be detected by chlorophyll fluorescence assay and hyperspectral images prior to the onset of visible symptoms, indicating the feasibility of early detection of diseases. However, to detect disease development by hyperspectral imaging, more detailed protocols and analyses are necessary. Taken together, change in chlorophyll fluorescence is a good parameter for early detection of P. cichorii infection in tomato plants. In addition, image-based visualization of infection severity before visual damage appearance will contribute to effective management of plant diseases.

The global incidence of breast cancer has increased. However, there are many impediments to the development of safe and effective anticancer drugs. The aim of the present study was to evaluate the effect of aviculin isolated from Lespedeza cuneata (Dum. Cours.) G. Don. (Fabaceae) on MCF-7 human breast cancer cells and determine the underlying mechanism. Using the bioassay-guided isolation by water soluble tetrazolium salt (WST-1)-based Ez-Cytox assay, nine compounds (four lignan glycosides (1–4), three flavonoid glycosides (5–7), and two phenolic compounds (8 and 9)) were isolated from the ethyl acetate (EA) fraction of the L. cuneata methanolic extract. Of these, aviculin (2), a lignan glycoside, was the only compound that reduced metabolic activity on MCF-7 cells below 50% (IC50: 75.47 ± 2.23 μM). The underlying mechanism was analyzed using the annexin V Alexa Fluor 488 binding assay and Western blotting. Aviculin (2) was found to induce apoptotic cell death through the intrinsic apoptosis pathway, as indicated by the increased expression of initiator caspase-9, executioner caspase-7, and poly (ADP-ribose) polymerase (PARP). Aviculin (2)-induced apoptotic cell death was accompanied by an increase in the Bax/Bcl-2 ratio. These findings demonstrated that aviculin (2) could induce breast cancer cell apoptosis through the intrinsic apoptosis pathway, and it can therefore be considered an excellent candidate for herbal treatment of breast cancer.

Hippophae rhamnoides L. (Elaeagnaceae; commonly known as “sea buckthorn” and “vitamin tree”), is a spiny deciduous shrub whose fruit is used in foods and traditional medicines. The H. rhamnoides fruit (berry) is rich in vitamin C, with a level exceeding that found in lemons and oranges. H. rhamnoides berries are usually washed and pressed to create pomace and juice. Today, the powder of the aqueous extract of H. rhamnoides berries are sold as a functional food in many countries. As part of our ongoing effort to identify bioactive constituents from natural resources, we aimed to isolate and identify those from the fruits of H. rhamnoides. Phytochemical analysis of the extract of H. rhamnoides fruits led to the isolation and identification of six compounds, namely, a citric acid derivative (1), a phenolic (2), flavonoids (3 and 4), and megastigmane compounds (5 and 6). Treatment with compounds 1–6 did not have any impact on the cell viability of RAW 264.7 mouse macrophages. However, pretreatment with these compounds suppressed lipopolysaccharide (LPS)-induced NO production in RAW 264.7 mouse macrophages in a concentration-dependent manner. Among the isolated compounds, compound 1 was identified as the most active, with an IC50 of 39.76 ± 0.16 μM. This value was comparable to that of the NG-methyl-L-arginine acetate salt, a nitric oxide synthase inhibitor with an IC50 of 28.48 ± 0.05 μM. Western blot analysis demonstrated that compound 1 inhibited the LPS-induced expression of IKKα/β (IκB kinase alpha/beta), I-κBα (inhibitor of kappa B alpha), nuclear factor kappa-B (NF-κB) p65, iNOS (inducible nitric oxide synthase), and COX-2 (cyclooxygenase-2) in RAW 264.7 cells. Furthermore, LPS-stimulated cytokine production was detected using a sandwich enzyme-linked immunosorbent assay. Compound 1 decreased interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) production in LPS-stimulated RAW 264.7 cells. In summary, the mechanism of action of 1 included the suppression of LPS-induced NO production in RAW 264.7 cells by inhibiting IKKα/β, I-κBα, NF-κB p65, iNOS, and COX-2, and the activities of IL-6 and TNF-α.

Genetic engineering is being used to enhance disease resistance and nutritional value of crops including rice plant. Considering the fast-growing agricultural biotechnology and rapidly increasing global area of transgenic crops, the risk evaluation on environment is necessary. In this study, we surveyed the difference of disease occurrence between transgenic rice variety, Iksan526 transformed with peanut stilbene synthase gene and non-transgenic rice varieties, Dongjin and Nampyeong in the field. Moreover, the possibility of gene transfer from transgenic rice to bacterial and fungal pathogens was investigated. The results of this study indicated that there was no significant difference in the occurrence and severity of the diseases between Iksan526 and Dongjin or Nampyeong. In addition, the results suggested that rice pathogen, such as Xanthomonas oryzae pv. oryzae, Rhizoctonia solani and Magnaporthe grisea did not take up stilbene synthase and bar genes under natural conditions. Moreover the transformed DNA was not transferred to the pathogens even in repetitive contacts.

Resvestrol has been known to inhibit bacterial and fungal growth in vitro, and can be accumulated in plant to concentrations necessary to inhibit microbial pathogens. Hence, stilbene synthase gene has been used to transform to synthesize resveratrol in heterologous plant species to enhance resistance against pathogens. In the present study, we investigated the antimicrobial activities of resveratrol and piceid to bacterial and fungal pathogens, which causing severe damages to rice plants. In addition, disease resistance was compared between transgenic rice varieties, Iksan 515 and Iksan 526 transformed with stlibene synthase gene and nontransgenic rice varieties, Dongjin and Nampyeong. Minimum inhibitory concentration of resveratrol for Burkolderia glumae was 437.5 μM, and the mycelial growth of Biplaris oryzae was slightly inhibited at concentration of 10 μM. However, other bacterial and fungal pathogens are not inhibited by resveratrol and piceid. The expression of the stilbene synthase gene in Iksan 515 and Iksan 526 did not significantly enhanced resistance against bacterial grain rot, bacterial leaf blight, sheath blight, and leaf blight. This study is the first report on the effect of resveratrol and piceid against pathogens of rice plant, and changes of disease resistance of transgenic rice plants transformed with stilbene synthase gene.

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a very serious disease in rice growing regions of the world. There are no effective ways of protecting rice from the disease. In this study, the bacteriophage (phage) mixtures infecting Xoo were investigated as biological control agent on BLB. The effects of pH, heat and ultraviolet on the stability of phages were investigated to check and increase the possibility of practical use in the field. Phages were rather stable between pH 5 and pH 10. The infectivity dropped sharply when the phages were incubated at 50℃ and more than 90% of the phages were inactivated after two minutes of ultraviolet treatment. The phages were stable for 7 days at the rice plant leaves, and the phages survived 10 times more than other treatments when mixed with skim milk. Although the skim milk increased the stability of the phages, the control efficacy was not effective. However, the phage mixtures reduced the occurrence of BLB when they were treated with Tecloftalam WP or Acibenzolar-S-methyl simultaneously. The results indicated that the Xoo phages could be used as an alternative control method to increase the control efficacy and reduce the use of agrochemicals.

We establish a new solution operator for the following problem -φp(u′)′=g, t∈(0,1), u(0)=0=u(1), where φp(x)=|x|p-2x, p>1. g may be singular at the boundary or change signs or may not be in L1(0,1) so that this solution operator can cover larger class of g than previously known ones. As an application, by checking complete continuity of the solution operator, we show the existence of nontrivial solutions for p-Laplacian φp(u′)′+λh(t)f(u(t))=0, t∈(0,1), u(0)=0=u(1), where λ>0 a parameter and f∈C(ℝ,ℝ) and f(0)>0 and h may change signs or may be beyond of L1(0,1).

This paper discusses a framework to design elements of the plant and control systems for floating offshore wind turbines in an integrated manner using linear parameter-varying models. Multiple linearized models derived from aero-elastic simulation software in different operating regions characterized by the incoming wind speed are combined to construct an approximate low-fidelity model of the system. The combined model is then used to generate open-loop, optimal control trajectories as part of a nested control co-design strategy that explores the system's power production and stability using the platform pitch tilt as a proxy in the context of crucial plant and control design decisions. The radial distance between the central and outer columns and the diameter of the outer columns of the semisubmersible platform are the plant design variables. The platform stability and power production are studied for different plant design decisions. The effect of plant decisions on subsequent power production and stability response of the floating wind turbine is quantified in terms of the levelized cost of energy. The results show that the inner-loop constraints and the plant design decisions affect the turbine's power and, subsequently, the cost of the system. [ABSTRACT FROM AUTHOR]