Development of sensitizer peptide-fused endolysin Lys1S-L9P acting against multidrug-resistant gram-negative bacteria.

The advent of multidrug-resistant (MDR) bacteria poses a major threat to public health, garnering attention to novel antibiotic replacements. Endolysin, a bacteriophage-derived cell wall-degrading enzyme, is a promising alternative to conventional antibiotics. However, it is challenging to control Gram-negative bacteria due to the presence of the outer membrane that shields the peptidoglycan layer from enzymatic degradation. To overcome this threshold, we constructed the fusion endolysin Lys1S-L9P by combining endolysin LysSPN1S with KL-L9P, a sensitizer peptide known to extend efficacy of antibiotics by perturbing the outer membrane of Gram-negative bacteria. In addition, we established a new endolysin purification procedure that increases solubility allowing a 4-fold increase in production yield of Lys1S-L9P. The sensitizer peptide-fused endolysin Lys1S-L9P exhibited high bactericidal effects against many MDR Gram-negative pathogens and was more effective in eradicating biofilms compared to LysSPN1S. Moreover, Lys1S-L9P showed potential for clinical use, maintaining stability at various storage temperatures without cytotoxicity against human cells. In the in vivo Galleria mellonella model, Lys1S-L9P demonstrated potent antibacterial activity against MDR Gram-negative bacteria without inducing any toxic activity. This study suggest that Lys1S-L9P could be a potential biocontrol agent to combat MDR Gram-negative bacteria.

Association and interaction between clinician-rated measures of depression and anxiety with heart rate variability in elderly patients with psychiatric disorders.

Background: Older adults are vulnerable to comorbid depression and anxiety symptoms; however, these conditions are widely underrecognized and often untreated. Understanding their combined manifestation using objective measurements, such as clinician-rated scales and heart rate variability (HRV), can help refine the diagnosis and select a treatment strategy for geriatric patients. Methods: This study included patients over 65 years who were mainly diagnosed with either category of depressive or anxiety disorders from the psychiatric outpatient clinic in a university hospital. A total of 114 patients met eligibility with a completed collection of electrocardiograms, the Hamilton Depression Rating Scale (HDRS; clinician-rated depression), and the Hamilton Anxiety Scale (HAS; clinician-rated anxiety) to assess the severity of symptoms. Both main and interaction effects between HDRS and HAS on HRV parameters were examined. Results: Significant interaction effects between clinician-rated depression and anxiety (HDRS × HAS) on HRV reduction in frequency parameters (i.e., nuLF, nuHF, LF/HF ratio) were found, which consistently indicated autonomic nervous system dysregulation. Findings imply that HRV could reflect synergistic effects of comorbid depressive and anxiety symptoms, perhaps due to the amplification of individual symptoms in geriatric patients. Conclusions: The results imply that using objective measurements can improve diagnostic accuracy, particularly in geriatric patients with comorbid status, and the normalization of the autonomic nervous system might be a candidate target for prevention and treatment.

Can We Notice the Suicidal Warning Signs of Adolescents With Different Psychometric Profiles Before Their Death?: Analysis of Teachers' Reports.

BACKGROUND: This study aimed to analyze the suicidal warning signs of Korean students with different psychometric profiles based on teacher reports. METHODS: This was a retrospective cohort study based on Korean school teachers' responses to the Student Suicide Report Form. In total, 546 consecutive cases of student suicide were reported from 2017 to 2020. After missing data were excluded, 528 cases were included. The report consisted of demographic factors, the Korean version of the Strengths and Difficulties Questionnaire (SDQ) for teacher reporting, and warning signs of suicide. Frequency analysis, multiple response analysis, the χ² test, and Latent Class Analysis (LCA) were performed. RESULTS: Based on the scores of the Korean version of the teacher-reported SDQ, the group was divided into nonsymptomatic (n = 411) and symptomatic (n = 117) groups. Based on the LCA results, four latent hierarchical models were selected. The four classes of deceased students showed significant differences in school type (χ² = 20.410, P < 0.01), physical illness (χ² = 7.928, P < 0.05), mental illness (χ² = 94.332, P < 0.001), trigger events (χ² = 14.817, P < 0.01), self-harm experience (χ² = 30.618, P < 0.001), suicide attempts (χ² = 24.072, P < 0.001), depressive symptoms (χ² = 59.561, P < 0.001), anxiety (χ² = 58.165, P < 0.001), impulsivity (χ² = 62.241, P < 0.001), and social problems (χ² = 64.952, P < 0.001). CONCLUSION: Notably, many students who committed suicide did not have any psychiatric pathology. The proportion of the group with a prosocial appearance was also high. Therefore, the actual suicide warning signals were similar regardless of students' difficulties and prosocial behaviors, so it is necessary to include this information in gatekeeper education.

Depression, Alcohol Misuse, and Suicide Attempt Among North Korean Refugee Women Exposed to Gender-Based Violence.

North Korean (NK) refugee women report a disproportionately high rate of suicide compared to the general South Korean (SK) population. NK refugee women's exposure to gender-based violence (GBV) is a risk factor for adverse mental health symptoms. However, the association between GBV exposure and mental health has received less scholarly attention. This study examined NK refugee women's exposure to GBV (i.e., sexual violence, human trafficking, and forced sex work) and explored whether it is associated with an increased risk of depression, alcohol misuse, and suicide attempts. A three-way interaction between depression, alcohol misuse, and suicide attempts among GBV-exposed NK refugee women was examined. Data from a snowball sample of 180NK refugee women were analyzed for this study. Findings show that 47.8% experienced GBV in either NK or intermediary countries. Multivariate analyses revealed that depression (OR = 1.13, p < .05) and alcohol misuse (OR = 3.01, p < .01) was significantly associated with suicide attempts in GBV-exposed groups. Results from the three-way interaction (GBV victimization × Depression × Alcohol misuse) suggest that GBV exposure and higher levels of depression were significantly associated with suicide attempts among NK refugee women with greater severity of alcohol misuse (OR = 1.75, p < .05). The findings indicate that NK refugee women with GBV exposure, depression, and alcohol misuse are at increased risk for suicide attempts. Study limitations included the use of snowball sampling and cross-sectional data. This study discusses implications for future research and targeted, trauma-informed treatments focused on GBV and mental health symptoms among NK refugee women.

Comparison of Suicide Attempts and Suicide Deaths by Jumping from a High Place in Korean Children and Adolescents.

Jumping from a high place is the most common method of suicide among Korean children and adolescents. The aim of this study was to examine the personal, family, and school life of Korean children and adolescents who chose jumping from a high place, among suicide attempts and suicide deaths, based on teachers' reports. Data on suicide attempts and suicide deaths by jumping from a high place in children and adolescents were collected through the Ministry of Education in South Korea from 2016 to 2018. We compared sociodemographic variables, suicide-related variables, emotional and behavioral status, school life related variables, and variables related to family problems among suicide deaths (n = 262), actual suicide attempts (n = 50), and interrupted or aborted suicide attempts (n = 210). There were differences in educational stage (p < 0.001), place of suicide (p < 0.001), presence of suicide note (p < 0.05) and previous suicide attempt (p < 0.001) among the three groups. The total difficulty score on the Strength Difficulty Questionnaire of interrupted or aborted suicide attempts was higher than that of the other two groups. Our study suggests that the suicide death group tend to present fewer personal and family pathologies and better school adjustment than the suicide attempt group.

Perceived social stigma, self-concealment, and suicide risk among North Korean refugee women exposed to traumatic events.

INTRODUCTION: Suicide among North Korean (NK) refugee women is one of the most concerning public health problems in South Korea. Pre-resettlement trauma exposure and post-resettlement factors can contribute to suicide risk among NK refugee women; however, few studies have explored these associations. METHODS: This study aimed to assess suicidal ideation and suicide attempts among NK refugee women in South Korea (N = 212) and to examine the impact of pre-resettlement trauma exposure on suicide risk. Perceived social stigma and self-concealment in the post-resettlement phases were investigated as moderating factors for suicide risk related to trauma exposure using multiple regression analyses. RESULTS: Trauma exposure significantly increased suicidal ideation severity and the risk of suicide attempt. Furthermore, perceived social stigma significantly moderated this relationship such that the impact of trauma exposure in the pre-resettlement phases was amplified as perceived social stigma increased. CONCLUSION: Based on our study findings, professionals working with refugee populations should assess for perceived social stigma and exposure to traumatic events to reduce and prevent suicidal ideation and attempts.

Workplace victimization and alcohol misuse among junior military personnel: Mediating the role of anger.

BACKGROUND: Workplace victimization is one of most serious problems for affecting alcohol misuse in junior military personnel (JMP) that has been largely overlooked in research attention. Studies on workplace victimization and alcohol misuse indicate anger as mediator. Workplace victimization may affect alcohol misuse (in)directly through the mediator. METHODS: A sample of JMP (N = 815) completed an offline survey, consisting of the revised Conflict Tactics Scale-2, Composite International Diagnostic Interview Screening Scale, and the Alcohol Use Disorders Identification Test. Frequency, t-test and chi-square test, and mediation analyses were conducted to assess the effects of workplace victimization on alcohol misuse, mediated via anger. RESULTS: Victims in the workplace showed higher level of anger and alcohol misuse. In mediation analyses, workplace victimization was related to higher levels of anger, which, in turn, were associated with greater alcohol misuse. LIMITATIONS: Study limitations included the use of cross-sectional data with the use of retrospective self-report. CONCLUSION: Workplace victimization in JMP is prevalent (17.7%), and alcohol misuse is associated with effects of workplace victimization and anger with full mediation path. Findings suggest that eliminating workplace victimization against JMP and intervention for anger should be focused upon, and implemented for online alcohol misuse prevention in the military context.

Suicidal Ideation and Attempt among North Korean Refugee Women in South Korea: Factors that Distinguish Suicide Attempt from Suicidal Ideation.

BACKGROUND: North Korean Refugee Women (NKRW) are at a high risk for suicide. However, few studies have examined risk factors for suicide among NKRW in South Korea. This study aimed to examine factors increasing risk for suicidal ideation and to identify factors differentiating suicide attempt from ideation among NKRW in South Korea. METHODS: A sample of 140 NKRW was analyzed; multinomial logistic regression was conducted to identify factors distinguishing respondents with (1) no suicidal ideation, (2) isolated suicidal ideation (without attempts), and (3) ideation with attempts. RESULTS: About 46% of the sample reported suicidal ideation, and about 18% attempted suicide during the past year. NKRW without any suicidal risk had significantly lower levels of social isolation (OR = 0.86, p = 0.02) and less exposure to traumatic events (OR = 0.89, p = 0.02) than those with suicidal ideation. NKRW who attempted suicide were more likely to have higher levels of stress than those with only suicidal ideation (OR = 1.40, p = 0.03). CONCLUSION: This study provides insights into suicide prevention among refugees and emphasized that post-migration life stress significantly differentiates suicidal ideation from attempt among NKRW. Intervening to address current life stress, traumatic experiences, and social isolation may help prevent refugee suicidal ideation and further attempt.

The Impact of Referral to Mental Health Services on Suicide Death Risk in Adolescent Suicide Survivors.

OBJECTIVES: This study aims to examine the effect of adolescent suicide survivors' experience on suicide death risk, and the effect of referral to mental health services (hereafter referral) in this regard. METHODS: This study used the data of 878 suicide-deceased and suicide-attempted adolescents aged 8-19 years, managed by the Suicide and School Mental Health Institute from 2016 to 2018. RESULTS: Regression analysis for main effects showed that although suicide experience had no direct effect on suicide death, non-referral status was associated with a greater risk of death by suicide. While the "non-suicide survivor with non-referral" and "suicide survivor with non-referral" groups showed 1.87 [adjusted odds ratio=1.87, 95% confidence interval (CI)=1.21-2.89] and 4.59 (adjusted odds ratio= 4.59, 95% CI=2.02-10.42) times higher odds of suicide death, respectively, the "suicide survivor with referral" group showed no difference compared to the "non-suicide survivor with referral" group. CONCLUSION: From these findings, there is a need to strengthen referral to mental health services and apply complicated grief treatment to improve the mental health of adolescent suicide survivors.

Characteristics of First Visit Pediatric Patients with Suicidal Ideation and Behavior: An 8-Year Retrospective Chart Review.

OBJECTIVES: Our study aimed to analyze the demographic and clinical characteristics of children and adolescents during their first visit to psychiatric outpatient departments for the management of suicidal ideation and behavior, and to compare the changes before and in 2012 or later. METHODS: This multicenter study was conducted at five university hospitals in a metropolitan area in South Korea. Medical records of patients aged 6-18 years were retrospectively reviewed from January 2009 to December 2016. Patients were analyzed by classifying them into suicidal and non-suicidal groups based on their visit to the hospital for management of suicidal ideation or suicide attempt and other mental problems, respectively. RESULTS: There were differences in the year of visit, diagnosis, education level, and referral sources between patients in the suicidal and non-suicidal groups. Multiple regression analysis was conducted based on the sex, education level, referral by school, and diagnosis of depression in patients in the suicidal group, which revealed significant association. CONCLUSION: Suicide-related problems were significantly associated with the sex, education level, referral by school, and a diagnosis of depression in the patients. A well-connected referral system would be necessary for professional mental health management of high-risk children and adolescents.

Military hazing and suicidal ideation among active duty military personnel: Serial mediation effects of anger and depressive symptoms.

BACKGROUND: Military hazing is one of most serious problems affecting suicidal ideation (SI) among active duty personnel, but has received limited research attention. Studies on hazing and SI indicate anger and depressive symptoms as mediators for SI. METHODS: A sample of active duty military personnel (N = 944) completed an offline survey, consisting of the revised Conflict Tactics Scale-2, Composite International Diagnostic Interview Screening Scale, and revised Columbia Suicide Severity Rating Scale. Frequency, bivariate correlation, and serial mediation analyses were conducted to assess the serial effects of military hazing on SI, mediated via anger and depressive symptoms. RESULTS: Military hazing, anger, depressive symptoms, and SI were positively related to each other in bivariate analyses. In serial mediation analyses, hazing was found to be a significant predictor of higher levels of anger, consequently triggering depressive symptoms, which, in turn, were associated with greater SI. LIMITATIONS: Study limitations included the use of cross-sectional data with the use of retrospective self-report. CONCLUSION: Hazing in the military is prevalent (17.6%), and SI is associated with serial effects of hazing, anger, and depressive symptoms with full mediation path. Findings suggest that policies that address reducing hazing and implementing clinical interventions specifically focused on symptoms of anger and depression may be important for decreasing SI in military personnel.