Effectiveness of written exposure therapy for Korean patients with post-traumatic stress disorder: non-randomized treatment-as-usual waitlist-controlled study.

Written exposure therapy (WET) is a five-session exposure-based protocol for treating post-traumatic stress disorder (PTSD). The brevity and tolerability of WET present the potential to overcome barriers in implementing evidence-based therapy for PTSD within the Korean mental healthcare system. This study investigated the effectiveness of WET in Korean patients with PTSD through a waitlist-controlled trial (KCT0008112). A total of 57 patients with PTSD were allocated non-randomly to either WET (n = 27) or treatment-as-usual waitlist groups (n = 30). Both groups were followed up until the twenty-fourth week after the initial session. Primary outcomes assessed included PTSD symptoms, depressive symptoms, and general function. In the WET group, significant improvements were observed in PTSD symptoms, depressive symptoms, and general function compared to the control group. After the waiting period, the waitlist group also participated in WET, and exhibited significant improvement in all scores. The between- and within-group effect sizes were large. The dropout rate in both groups was 10.9%, and the mean satisfaction ratings were 28.24 ± 3.33 (range 22-32; scale range 8-32). The present study provides evidence of WET successfully reducing PTSD and depressive symptoms and improving general function among Korean patients with PTSD. Moreover, WET was well tolerated and received by Korean patients with PTSD.

Posttraumatic stress disorder symptoms and neurocognitive functioning in fire fighters: The mediating role of sleep problems and resilience.

BACKGROUND: Firefighters are often exposed to terrible and dangerous scenes due to their duties, and thus have a high risk of developing posttraumatic stress disorder(PTSD). The purpose of the study is to examine the relationship between PTSD symptoms, sleep problems, resilience and neurocognitive functioning of firefighters, and to identify the sequential mediating effects of sleep problems and resilience on the relationship between PTSD symptoms and neurocognitive functioning (especially psychomotor speed and processing speed). METHODS: Data were collected from 325 firefighters in eight fire departments in four regions of Korea. Subjects performed neurocognitive function tests and completed the following questionnaires: Primary Care PTSD Screening, Pittsburgh Sleep Quality Index-K and Connor-Davidson Resilience Scale-2. The correlation and dual mediation effects were analysed using SPSS 22.0 program and PROCESS macro 3.4 program. RESULTS: PTSD symptoms, neurocognitive functioning, sleep problems and resilience were significantly correlated with each other. In the sequential mediation model, the relationship between PTSD and psychomotor speed/processing speed was sequentially mediated by sleep problems and resilience after adjusting for demographic variables. CONCLUSIONS: The PTSD symptoms of firefighters were related to a sequential link between sleep problems, low resilience and decreased neurocognitive function. These findings could serve as a basis for more effective and integrated interventional strategies for facilitating better neurocognitive functioning in firefighters.

Bereaved families are still embittered after the Sewol ferry accident in Korea: A follow-up study 18 and 30months after the disaster.

INTRODUCTION: The Sewol ferry accident that occurred in April 2014 was one of the most tragic human-made disasters in Korean history. Due to the deaths of hundreds of children, bereaved families likely feel embittered; however, there is little extant research documenting embitterment among those who experienced the disaster. Consequently, we investigated bereaved family members' embitterment and other psychiatric symptoms 18months and 30months after the disaster. METHODS: Data from a cross-sectional survey were obtained 18months (Time 1) and 30months (Time 2) after the disaster. We ascertained socio-demographic variables and variables obtained from a self-reporting questionnaire (i.e., depression, anxiety, posttraumatic stress disorder, complicated grief, and embitterment) among 56 bereaved family members. RESULTS: Bereaved families showed substantial embitterment at Time 1 (64.3%), which increased at Time 2 (76.8%, t=1.761, p=0.084). The participants who displayed increased embitterment at Time 2 also increased in anxiety, post-traumatic stress symptoms, and complicated grief (but not depression). Furthermore, participants who displayed decreased embitterment at Time 2 also decreased in all other psychiatric symptoms. (time×group interaction in depression (F 0.644, p=0.426), anxiety (F 4.970, p=0.030), PTSD (F 10.699, p=0.002), and complicated grief (F 8.389, p=0.005)). CONCLUSIONS: Embitterment of bereaved families had not ceased after 18months and even increased 1year later. Additionally, as embitterment increased, many other psychiatric symptoms also increased, and vice versa. Our results suggest that embitterment is associated or can even influence other psychiatric symptoms; therefore, embitterment should be examined after disasters.

Improvement of succinate production by release of end-product inhibition in Corynebacterium glutamicum.

Succinate is a renewable-based platform chemical that may be used to produce a wide range of chemicals including 1,4-butanediol, tetrahydrofurane, and γ-butyrolactone. However, industrial fermentation of organic acids is often subject to end-product inhibition, which significantly retards cell growth and limits metabolic activities and final productivity. In this study, we report the development of metabolically engineered Corynebacterium glutamicum for high production of succinate by release of end-product inhibition coupled with an increase of key metabolic flux. It was found that the rates of glucose consumption and succinate production were significantly reduced by extracellular succinate in an engineered strain, S003. To understand the mechanism underlying the inhibition by succinate, comparative transcriptome analysis was performed. Among the downregulated genes, overexpression of the NCgl0275 gene was found to suppress the inhibition of glucose consumption and succinate production, resulting in a 37.7% increase in succinate production up to 55.4g/L in fed-batch fermentation. Further improvement was achieved by increasing the metabolic flux from PEP to OAA. The final engineered strain was able to produce 152.2g/L succinate, the highest production reported to date, with a yield of 1.1g/g glucose under anaerobic condition. These results suggest that the release of end-product inhibition coupled with an increase in key metabolic flux is a promising strategy for enhancing production of succinate.

Direct fermentation route for the production of acrylic acid.

There have been growing concerns regarding the limited fossil resources and global climate changes resulting from modern civilization. Currently, finding renewable alternatives to conventional petrochemical processes has become one of the major focus areas of the global chemical industry sector. Since over 4.2 million tons of acrylic acid (AA) is annually employed for the manufacture of various products via petrochemical processes, this chemical has been the target of efforts to replace the petrochemical route by ecofriendly processes. However, there has been limited success in developing an approach combining the biological production of 3-hydroxypropionic acid (3-HP) and its chemical conversion to AA. Here, we report the first direct fermentative route for producing 0.12 g/L of AA from glucose via 3-HP, 3-HP-CoA, and Acryloyl-CoA, leading to a strain of Escherichia coli capable of directly producing acrylic acid. This route was developed through extensive screening of key enzymes and designing a novel metabolic pathway for AA.

Protective Behaviors Against COVID-19 and Related Factors in Korean Adults With Depressive Symptoms: Results From an Analysis of the 2020 Korean Community Health Survey.

OBJECTIVE: This study evaluated protective behaviors against coronavirus disease-2019 (COVID-19) and related factors in individuals with depressive symptoms. METHODS: This cross-sectional study included data from the 2020 Korean Community Health Survey. Depressive symptoms, COVID- 19 protection behaviors, and related factors were investigated in 228,485 people. Chi-square test and logistic regression analysis were used to analyze categorical variables. Statistical analysis was performed using SPSS software (version 27.0). RESULTS: In the study, 3.9% (n=8,970) had depressive symptoms. The prevalence of depressive symptoms was higher in individuals in their 19-39 years , and ≥60s than in those in their 40-59 years (p<0.001). Lower education level and household income were associated with a higher prevalence of depression (p<0.001). Among the various occupations, service workers had the highest prevalence of depressive symptoms (p<0.001). Individuals with depressive symptoms were less likely to adopt protective behaviors against COVID-19 (p<0.001) or exhibit concerns regarding death and economic damage (p<0.001) compared to individuals without depressive symptoms. Individuals with depressive symptoms were more likely to have unhealthy behaviors than those without depressive symptoms (p<0.001). Individuals with depressive symptoms considered that the COVID-19 response by the government and other organizations was inadequate (p<0.001). CONCLUSION: During the COVID-19 pandemic, individuals with depressive symptoms faced greater challenges in adopting protective behaviors. Therefore, it is crucial to develop strategies to protect people with depressive symptoms during another pandemic in the future.

Preventive effect of Lacticaseibacillus paracasei LMT18-32 on Porphyromonas gingivalis induced periodontitis.

Periodontitis is a severe gum infection leading to chronic inflammation in the gums, damage of tissues around teeth, and destruction of alveolar bones. Porphyromonas gingivalis is the major causative pathogen that induces periodontitis. Numerous probiotic bacteria are reported to produce antibacterial substances against pathogens especially oral pathogens, and these are proposed as preventive measures for periodontitis. In this study, Lacticaseibacillus paracasei LMT18-32 was evaluated and its antibacterial activity against P. gingivalis, and antioxidant activity in vitro were established. In addition, when L. paracasei LMT18-32 was administered to periodontitis induced mice, it successfully alleviated the alveolar bone loss and suppressed induced expression of proinflammatory and tissue destruction related genes in the gingival tissue. In conclusion, L. paracasei LMT18-32 is proposed as a potential probiotics to prevent periodontitis.

Characterization and genomic analysis of two Staphylococcus aureus bacteriophages isolated from poultry/livestock farms.

Staphylococcus aureus is one of the most important pathogens, causing various diseases in humans and animals. As methicillin-resistant S. aureus (MRSA) has become increasingly prevalent, controlling this pathogen with standard antibiotic treatment has become challenging. Bacteriophages (phages) have attracted interest as alternative antibacterial agents to control MRSA. In this study, we isolated six S. aureus phages from soils of poultry/livestock farms. Based on the results of host range determination with 150 S. aureus strains and restriction enzyme treatment of phage DNA, two phages, designated SP5 and SP6, were selected for further characterization and genome sequencing. Both SP5 and SP6 were classified as members of the family Siphoviridae. The genome of SP5 comprises 43 305 bp and contains 63 ORFs, while the SP6 genome comprises 42 902 bp and contains 61 ORFs. Although they have different host spectra, the phage genomes exhibit high nucleotide similarity to each other. Adsorption assay results suggested that the host range determinants of the two phages are involved in both adsorption and infection. Comparative genomic analyses of the two phages provided evidence that the lysogenic/lytic control module and tail proteins may be important for host specificity.

The effects of sociodemographic factors on help-seeking for depression: Based on the 2017-2020 Korean Community Health Survey.

When individuals face psychological difficulties that exceed their resources, consulting professionals for mental health treatment can be an effective way to overcome these difficulties. However, in general, only a few patients receive treatment for depression. The goal of the present study was to explore the help-seeking behaviors of currently employed individuals with depression and the factors influencing their help-seeking behaviors. This study used raw data from the Korean Community Health Survey (KCHS) obtained from 2017 to 2020. A total of 6,505 employed individuals, who responded as having experiences of sadness or hopelessness that caused problems in their lives for more than two weeks and who scored more than nine points on the Patient Health Questionnaire-9, were included in our analysis. Help-seeking behavior was measured as receiving expert advice due to feelings of sadness or hopelessness. Of the 6,505 people with depression, only 1,781 (27.38%) received professional counseling for it. Male participants (adjusted odds ratio [aOR] = 1.31, 95% confidence interval [CI] = 1.157-1.487), those aged 45-64 years (aOR = 1.192, 95% CI = 1.022-1.389) and more than 75 years (aOR = 1.446, 95% CI = 1.059-1.973), those not having a Medical Aid program (aOR = 1.750, 95% CI = 1.375-2.226), and those having low educational levels (aOR = .896, 95% CI = .830-.968) were less likely to seek professional help for depression. Our study found that help-seeking behaviors for depression in the Korean population were low. Furthermore, we identified the characteristics associated with individuals with depressive symptoms who chose not to receive help from mental health professionals. The results of this study provide insights to guide national interventions to increase help-seeking behaviors for depression.

Validating a Korean Version of the Single-Item Burnout Measure for Evaluating Burnout Among Doctors.

OBJECTIVE: It is essential to measure the effect of burnout on doctors because burnout can affect doctors' mental health as well as the functioning of medical practice. This study aims to validate a Korean version of the single-item burnout measure (SIBM), which was developed to quickly measure the level of burnout among doctors. METHODS: Through an online survey, a self-report questionnaire was administered to 324 public health doctors in Korea. The Korean version of the SIBM was validated against the Maslach Burnout Inventory-General Survey (MBI-GS), the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7) screening tool, the Perceived Stress Scale (PSS), and the Vaccination Attitudes Examination (VAX) scale. Pearson correlation coefficients and analysis of variance (ANOVA) were used to determine the association between the SIBM and other scales. ANOVA was additionally used to determine the associations between the subscales of the MBI-GS and those of the SIBM. RESULTS: The correlation coefficient between the SIBM and the MBI-GS, PHQ-9, GAD-7, and PSS was positive (p<0.01), and the correlation coefficient between the SIBM and the VAX scale was not significant. Therefore, convergent and discriminant validity was verified. Exhaustion and cynicism, which were correlated with the SIBM, with r2=0.43 (p<0.01) and 0.48 (p<0.01), yielded R2 scores of 0.27 (p<0.01) and 0.20 (p<0.01) in ANOVA. CONCLUSION: The Korean version of the SIBM is an appropriate screening tool for burnout. It can be evaluated in a short time, thereby enhancing continuous follow-up observations and response rates to burnout.

Characterization of LysB4, an endolysin from the Bacillus cereus-infecting bacteriophage B4.

BACKGROUND: Bacillus cereus is a foodborne pathogen that causes emetic or diarrheal types of food poisoning. The incidence of B. cereus food poisoning has been gradually increasing over the past few years, therefore, biocontrol agents effective against B. cereus need to be developed. Endolysins are phage-encoded bacterial peptidoglycan hydrolases and have received considerable attention as promising antibacterial agents. RESULTS: The endolysin from B. cereus phage B4, designated LysB4, was identified and characterized. In silico analysis revealed that this endolysin had the VanY domain at the N terminus as the catalytic domain, and the SH3_5 domain at the C terminus that appears to be the cell wall binding domain. Biochemical characterization of LysB4 enzymatic activity showed that it had optimal peptidoglycan hydrolase activity at pH 8.0-10.0 and 50°C. The lytic activity was dependent on divalent metal ions, especially Zn2+. The antimicrobial spectrum was relatively broad because LysB4 lysed Gram-positive bacteria such as B. cereus, Bacillus subtilis and Listeria monocytogenes and some Gram-negative bacteria when treated with EDTA. LC-MS analysis of the cell wall cleavage products showed that LysB4 was an L-alanoyl-D-glutamate endopeptidase, making LysB4 the first characterized endopeptidase of this type to target B. cereus. CONCLUSIONS: LysB4 is believed to be the first reported L-alanoyl-D-glutamate endopeptidase from B. cereus-infecting bacteriophages. The properties of LysB4 showed that this endolysin has strong lytic activity against a broad range of pathogenic bacteria, which makes LysB4 a good candidate as a biocontrol agent against B. cereus and other pathogenic bacteria.

Monitoring the metabolic status of geobacter species in contaminated groundwater by quantifying key metabolic proteins with Geobacter-specific antibodies.

Simple and inexpensive methods for assessing the metabolic status and bioremediation activities of subsurface microorganisms are required before bioremediation practitioners will adopt molecular diagnosis of the bioremediation community as a routine practice for guiding the development of bioremediation strategies. Quantifying gene transcripts can diagnose important aspects of microbial physiology during bioremediation but is technically challenging and does not account for the impact of translational modifications on protein abundance. An alternative strategy is to directly quantify the abundance of key proteins that might be diagnostic of physiological state. To evaluate this strategy, an antibody-based quantification approach was developed to investigate subsurface Geobacter communities. The abundance of citrate synthase corresponded with rates of metabolism of Geobacter bemidjiensis in chemostat cultures. During in situ bioremediation of uranium-contaminated groundwater the quantity of Geobacter citrate synthase increased with the addition of acetate to the groundwater and decreased when acetate amendments stopped. The abundance of the nitrogen-fixation protein, NifD, increased as ammonium became less available in the groundwater and then declined when ammonium concentrations increased. In a petroleum-contaminated aquifer, the abundance of BamB, an enzyme subunit involved in the anaerobic degradation of mono-aromatic compounds by Geobacter species, increased in zones in which Geobacter were expected to play an important role in aromatic hydrocarbon degradation. These results suggest that antibody-based detection of key metabolic proteins, which should be readily adaptable to standardized kits, may be a feasible method for diagnosing the metabolic state of microbial communities responsible for bioremediation, aiding in the rational design of bioremediation strategies.

Roles of RpoN in the resistance of Campylobacter jejuni under various stress conditions.

BACKGROUND: Campylobacter jejuni is a leading foodborne pathogen worldwide. Despite the fastidious nature of C. jejuni growth, increasing numbers of human campylobacteriosis suggest that C. jejuni may possess unique mechanisms to survive under various stress conditions. C. jejuni possesses only three sigma factors (FliA, RpoD, and RpoN) and lacks stress-defense sigma factors. Since FliA and RpoD are dedicated to flagella synthesis and housekeeping, respectively, in this study, we investigated the role of RpoN in C. jejuni's defense against various stresses. RESULTS: Survivability of an rpoN mutant was compared with the wild-type C. jejuni under various stress conditions. While the growth of the rpoN mutant was as comparably as that of the wild type in shaking cultures, the rpoN mutant exhibited significant survival defects when cultured statically. The rpoN mutant was more sensitive to osmotic stress (0.8% NaCl) with abnormally-elongated cell morphology. Compared to the wile type, the rpoN mutant was more susceptible to acid stress (pH 5) and more resistant to hydrogen peroxide. However, the rpoN mutation had little effect on the resistance of C. jejuni to alkaline pH, heat, cold and antimicrobials. CONCLUSIONS: The results demonstrate that RpoN plays an important role in C. jejuni's defense against various stresses which this bacterial pathogen may encounter during transmission to and infection of humans.

The Interaction of Inflammatory Markers and Alcohol-Use on Cognitive Function in Korean Male Firefighters.

OBJECTIVE: Cognitive functions have been shown to become impaired due to alcoholism. Recently, neuroinflammation gained attention for playing a role in the neurotoxic effect of alcohol. However, there is limited data on the relationship between alcohol and cognitive function, based on the mechanism of inflammation. This study examined whether the interaction between alcohol use and pro-inflammatory biomarkers is related to cognitive function in Korean male firefighters. METHODS: A total of 474 firefighters were assessed for alcohol-related problems using CAGE, cognitive functions, and pro-inflammatory biomarkers (CRP, IL-6, TNF-α). Sequential multiple regression analyses were conducted to determine if inflammatory markers moderate the relationship between alcohol use and cognitive function. RESULTS: Only a decreased attentional function was associated with the interaction of alcohol use and inflammatory markers, after controlling for age, sex, body mass index, lipid profiles, smoking, depression, fatigue, self-reported hypertension, diabetes, and musculoskeletal problems. CONCLUSION: This study revealed that the interaction between alcohol use and inflammation is related to attentional function in Korean male firefighters. Additionally, this cross-sectional study suggests that diminishing attention, related to alcohol use, may be based on the mechanism of inflammation.

An Open Pilot Trial of Written Exposure Therapy for Patients With Post-Traumatic Stress Disorder in Korea.

OBJECTIVE: Written exposure therapy (WET) is exposure therapy for post-traumatic stress disorder (PTSD). Compared to evidencebased treatments for PTSD, WET requires only five sessions, has a shorter session time, and no between-session assignments. The current study examined the efficacy of WET among Korean patients with PTSD due to various traumatic events on PTSD symptoms, depressive symptoms, and global functioning levels. METHODS: The study recruited 41 patients with a current primary diagnosis of PTSD in psychiatric outpatient clinics. Assessments were conducted at baseline, and at 6, 12, and 24 weeks following the first treatment session. RESULTS: In total, 25 patients started WET. Findings showed a significant reduction in the rate of PTSD diagnosis and symptom severity scores. Fourteen of 23 (60.9%) patients at 6 weeks, 15 of 22 (68.2%) patients at 12 weeks, and 14 of 18 (77.8%) patients at 24 weeks no longer met the diagnosis of PTSD. Depressive symptoms and global function scores also improved after WET. The dropout rate was 8% (n=2). CONCLUSION: This study suggests the feasibility of implementing WET among various types of patients with PTSD in Korea and other Asian countries.

Mlc regulation of Salmonella pathogenicity island I gene expression via hilE repression.

The global regulator Mlc is a repressor of several genes and operons that are involved in sugar uptake and metabolism. A Salmonella enterica serovar Typhimurium mlc mutant showed reduced levels of invasion and cytotoxicity compared to the wild-type, and exhibited reduced expression levels of hilD, hilA and invF, which are regulatory genes in the Salmonella pathogenicity island 1 (SPI1). However, the effects of Mlc on hilD expression and bacterial invasiveness were not seen in the hilE mutant, and hilE expression was increased in the mlc mutant, which suggests that Mlc exerts positive effects on the expression of SPI1 genes by reducing the expression of HilE, which is known to down-regulate the expression of SPI1 genes through direct interaction with HilD. We found that the two known promoters of hilE were not modulated by Mlc, and we identified a third promoter, designated P3, which was repressed by Mlc. The gel mobility shift assay and footprinting analysis revealed that Mlc repressed hilE in a direct manner by binding to two distinct sites in the hilE P3 promoter region. The specific down-regulation of hilD observed in the presence of Mlc regulon-inducible sugars, such as glucose and mannose, could not be detected in the mlc mutant. Based on these results, we propose that Mlc functions to sense the availability of sugars and is linked to virulence gene regulation by its ability to control hilE expression in Salmonella.

Role of the DksA-like protein in the pathogenesis and diverse metabolic activity of Campylobacter jejuni.

DksA is well known for its regulatory role in the transcription of rRNA and genes involved in amino acid synthesis in many bacteria. DksA has also been reported to control expression of virulence genes in pathogenic bacteria. Here, we elucidated the roles of a DksA-like protein (CJJ81176_0160, Cj0125c) in the pathogenesis of Campylobacter jejuni. As in other bacteria, transcription of stable RNA was repressed by the DksA-like protein under stress conditions in C. jejuni. Transcriptomic and proteomic analyses of C. jejuni 81-176 and an isogenic mutant lacking the DksA-like protein showed differential expression of many genes involved in amino acid metabolism, iron-related metabolism, and other metabolic reactions. Also, the C. jejuni DksA-like protein mutant exhibited a decreased ability to invade intestinal cells and induce release of interleukin-8 from intestinal cells. These results suggest that the DksA-like protein plays an important regulatory role in diverse metabolic events and the virulence of C. jejuni.

RstA-promoted expression of the ferrous iron transporter FeoB under iron-replete conditions enhances Fur activity in Salmonella enterica.

The Fur protein is a primary regulator that monitors and controls cytoplasmic iron levels. We now report the identification of a regulatory pathway mediated by the Salmonella response regulator RstA that promotes Fur activity. Genome-wide expression experiments revealed that under iron-replete conditions, expression of the RstA protein from a plasmid lowered transcription levels of various genes involved in iron acquisition. The RstA protein controlled iron-responsive genes through the Fur-Fe(II) protein because deletion of the fur gene or iron depletion abrogated RstA-mediated repression of these genes. The RstA protein maintained wild-type levels of the Fur protein but exceptionally activated transcription of the feoAB operon encoding the ferrous iron transporter FeoB by binding directly to the feoA promoter. This FeoB induction resulted in increased ferrous iron uptake, which associates with the Fur protein because lack of RstA-dependent transcriptional activation of the feoA promoter and feoB-deletion abolished repression of the Fur target genes by the RstA protein. Under iron-replete conditions, RstA expression retarded Salmonella growth but enabled the Fur protein to repress the target genes beyond the levels which were simply accomplished by iron.

Development of a novel vector system for programmed cell lysis in Escherichia coli.

Although widely used as a host for recombinant protein production, Escherichia coli is unsuitable for massive screening of recombinant clones, owing to its poor secretion of proteins. A vector system containing T4 holin and T7 lysozyme genes under the control of the ptsG promoter derivative that is inducible in the absence of glucose was developed for programmed cell lysis of E. coli. Because E. coli harboring the vector grows well in the presence of glucose, but is lysed upon glucose exhaustion, the activity of the foreign gene expressed in E. coli can be monitored easily without an additional step for cell disruption after the foreign gene is expressed sufficiently with an appropriate concentration of glucose. The effectiveness of the vector was demonstrated by efficient screening of the amylase gene from a Bacillus subtilis genomic library. This vector system is expected to provide a more efficient and economic screening ofbioactive products from DNA libraries in large quantities.