Socioeconomic Characteristics and Attitudes Toward Suicide Among Gatekeepers in a Suicide Prevention Project in Gyeongsangbuk-do / 생물치료정신의학

Objectives@#This study identifies the socioeconomic characteristics and attitudes toward suicide (ATTS) of gatekeepers participating in a suicide prevention project in Gyeongsangbuk-do. Through this study we hope to increase the understanding required to prevent suicide in the community. @*Methods@#We conducted a survey from October 11 to November 4, 2022, with 1,284 individuals from private organizations who participated in the suicide prevention project between September 23 and November 30, 2022. The survey established demographic characteristics, experience in participating in suicide prevention projects, awareness and need for suicide prevention and mental health services, and ATTS. The study conducted cross-analysis and chi-square tests to identify differences in responses according to demographics. An independent sample t-test, one-way analysis of variance, and Scheffe’s post hoc test were performed to analyze the comparisons between each measurement factor. SPSS 21.0 was used to process data and the level of statistical significance was set to p<0.05. @*Results@#The gatekeepers’ ATTS were moderate, with an average of 3.11 out of 5. Specifically, preventability obtained the highest score (4.07), followed by preparedness to prevent (3.96), incomprehensibility (3.74), and noncommunication (3.34). Conversely, resignation obtained the lowest score (2.05), followed by tabooing (2.32) and relation-caused (2.51). The scores for preventability and preparedness to prevent increased with sustained participation in the suicide prevention program, while those for suicidal process decreased. @*Conclusions@#Gatekeepers’ ATTS may improve as a result of participation in the suicide prevention project, with better results with continued participation. Thus, actively recruiting more gatekeepers and keeping them engaged in the program may help prevent suicide.

Comparative Analysis of Liver Injury-Associated Cytokines in Acute Hepatitis A and B

PURPOSE: Acute hepatitis A (AHA) and acute hepatitis B (AHB) are caused by an acute infection of the hepatitis A virus and the hepatitis B virus, respectively. In both AHA and AHB, liver injury is known to be mediated by immune cells and cytokines. In this study, we measured serum levels of various cytokines and T-cell cytotoxic proteins in patients with AHA or AHB to identify liver injury-associated cytokines. MATERIALS AND METHODS: Forty-six patients with AHA, 16 patients with AHB, and 14 healthy adults were enrolled in the study. Serum levels of 17 cytokines and T-cell cytotoxic proteins were measured by enzyme-linked immunosorbent assays or cytometric bead arrays and analyzed for correlation with serum alanine aminotransferase (ALT) levels. RESULTS: Interleukin (IL)-18, IL-8, CXCL9, and CXCL10 were significantly elevated in both AHA and AHB. IL-6, IL-22, granzyme B, and soluble Fas ligand (sFasL) were elevated in AHA but not in AHB. In both AHA and AHB, the serum level of CXCL10 significantly correlated with the peak ALT level. Additionally, the serum level of granzyme B in AHA and the serum level of sFasL in AHB correlated with the peak ALT level. CONCLUSION: We identified cytokines and T-cell cytotoxic proteins associated with liver injury in AHA and AHB. These findings deepen the existing understanding of immunological mechanisms responsible for liver injury in acute viral hepatitis.

DNA immunization of Mycobacterium tuberculosis resuscitation-promoting factor B elicits polyfunctional CD8+ T cell responses

PURPOSE: T cell-mediated immune responses, and particularly activation of polyfunctional T cells that simultaneously produce multiple cytokines, are necessary for the control of Mycobacterium tuberculosis. In the present study, we examined if DNA immunization of Mycobacterium tuberculosis resuscitation-promoting factor B (RpfB) elicits polyfunctional T cell responses in mice. MATERIALS AND METHODS: C57BL/6 mice were immunized intramuscularly three times, at 3-week intervals, with RpfB-expressing plasmid DNA. For comparison, protein immunization was performed with recombinant RpfB in control mice. After immunization, RpfB-specific T cell responses were assessed by interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot assay and intracellular cytokine staining (ICS), and T cell polyfunctionality was assessed from the ICS data. RESULTS: RpfB DNA immunization induced not only humoral immune responses, but also CD8+ and CD4+ T cell responses. Immunodominant T-cell epitopes were identified within RpfB by assays with overlapping peptides. RpfB DNA immunization elicited a polyfunctional CD8+ T cell response that was dominated by a functional phenotype of IFN-gamma+/TNF-alpha+/IL-2-/CD107a+. CONCLUSION: RpfB DNA immunization elicits polyfunctional CD8+ T cell responses, suggesting that RpfB DNA immunization might induce protective immunity against tuberculosis.

T-Cell Dysfunction and Inhibitory Receptors in Hepatitis C Virus Infection

Dysfunction of the virus-specific T cells is a cardinal feature in chronic persistent viral infections such as one caused by hepatitis C virus (HCV). In chronic HCV infection, virus-specific dysfunctional CD8 T cells often overexpress various inhibitory receptors. Programmed cell death 1 (PD-1) was the first among these inhibitory receptors that were identified to be overexpressed in functionally impaired T cells. The roles of other inhibitory receptors such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and T cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) have also been demonstrated in T-cell dysfunctions that occur in chronic HCV patients. Blocking these inhibitory receptors in vitro restores the functions of HCV-specific CD8 T cells and allows enhanced proliferation, cytolytic activity and cytokine production. Therefore, the blockade of the inhibitory receptors is considered as a novel strategy for the treatment of chronic HCV infection.