We developed a new concentration kit, called the ParaEgg (PE), for easy detection trematode eggs from fecal samples in endemic areas of clonorchiasis and metagonimiasis in Korea. To create a standard of detection efficiency, 120 fecal samples were examined using the water–ether concentration method (WECM). The PE kit and Mini ParaSep (PS) kit were used to compare the detection sensitivity of 100 egg-positive and 20 egg-negative samples in WECM. Additionally, stool samples, which were intentionally spiked with 10, 20, and 30 Clonorchis sinensis eggs, were evaluated to assess the sensitivity in lowinfection cases. The PE and PS kits showed detection rates of 100% and 92%, respectively, from 100 egg-positive samples in WECM. Meanwhile, eggs were detected in 3 (PE) and 2 (PS) out of 20 egg-negative samples in WECM. The PE kit detected the highest number of eggs per gram of feces (727 on average), followed by the WECM (524) and PS kit (432). In fecal samples that were intentionally spiked with 10, 20, and 30 C. sinensis eggs, PE only detected eggs 2 out of 5 samples in 10 eggs spiked (40%), and the detection rates were 80% and 100%, respectively. The PE kit enabled a more accurate identification of trematode eggs because of the clearance of small fecal debris in the microscopic field. In conclusion, the PE kit is obviously helpful to detect and identify trematode eggs in stool examinations especially in endemic areas of clonorchiasis and metagonimiasis.

Malaria is a global disease affecting a large portion of the world’s population. Although vaccines have recently become available, their efficacies are suboptimal. We generated virus-like particles (VLPs) that expressed either apical membrane antigen 1 (AMA1) or microneme-associated antigen (MIC) of Plasmodium berghei and compared their efficacy in BALB/c mice. We found that immune sera acquired from AMA1 VLP- or MIC VLP-immunized mice specifically interacted with the antigen of choice and the whole P. berghei lysate antigen, indicating that the antibodies were highly parasite-specific. Both VLP vaccines significantly enhanced germinal center B cell frequencies in the inguinal lymph nodes of mice compared with the control, but only the mice that received MIC VLPs showed significantly enhanced CD4+ T cell responses in the blood following P. berghei challenge infection. AMA1 and MIC VLPs significantly suppressed TNF-α and interleukin-10 production but had a negligible effect on interferon-γ. Both VLPs prevented excessive parasitemia buildup in immunized mice, although parasite burden reduction induced by MIC VLPs was slightly more effective than that induced by AMA1. Both VLPs were equally effective at preventing body weight loss. Our findings demonstrated that the MIC VLP was an effective inducer of protection against murine experimental malaria and should be the focus of further development.

Background: Exercise capacity is known to be an independent predictor of cardiovascular events and mortality. However, most previous studies were based on Western populations.Further study is warranted for Asian patients according to ethnic or national standards. We aimed to compare prognostic values of Korean and Western nomograms for exercise capacity in Korean patients with cardiovascular disease (CVD). Methods: In this retrospective cohort study, we enrolled 1,178 patients (62 ± 11 years;78% male) between June 2015 and May 2020, who were referred for cardiopulmonary exercise testing in our cardiac rehabilitation program. The median follow-up period was 1.6 years. Exercise capacity was measured in metabolic equivalents by direct gas exchange method during the treadmill test. The nomogram for exercise capacity from healthy Korean individuals and a previous landmark Western study was used to determine the percentage of predicted exercise capacity. The primary endpoint was the composite of major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, repeat revascularization, stroke and hospitalization for heart failure). Results: A multivariate analysis showed that the risk of primary endpoint was more than double (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.10–4.40) in the patients with lower exercise capacity (< 85% of predicted) by Korean nomogram. The lower exercise capacity was one of the strong independent predictors along with left ventricular ejection fraction, age, and level of hemoglobin. However, the lower exercise capacity by Western nomogram could not predict the primary endpoint (HR, 1.33; 95% CI, 0.85–2.10). Conclusion Korean patients with CVD with lower exercise capacity have higher risk of MACE.Considering inter-ethnic differences in cardiorespiratory fitness, the Korean nomogram provides more suitable reference values than the Western nomogram to determine lower exercise capacity and predict cardiovascular events in Korean patients with CVD.

Inflammatory bowel disease (IBD) is a chronic and recurrent illness of the gastrointestinal tract. Treatment of IBD traditionally involves the use of aminosalicylic acid and steroids, while these drugs has been associated with untoward effects and refractoriness. The absence of effective treatment regimen against IBD has led to the exploration of new targets. Parasites are promising as an alternative therapy for IBD. Recent studies have highlighted the use of parasite-derived substances, such as excretory secretory products, extracellular vesicles (EVs), and exosomes, for the treatment of IBD. In this report, we examined whether EVs secreted by Giardia lamblia could prevent colitis in a mouse model. G. lamblia EVs (GlEVs) were prepared from in vitro cultures of Giardia trophozoites. Clinical signs, microscopic colon tissue inflammation, and cytokine expression levels were detected to assess the effect of GlEV treatment on dextran sulfate sodium (DSS)-induced experimental murine colitis. The administration of GlEVs prior to DSS challenge reduced the expression levels of pro-inflammatory cytokines, including tumor necrosis factor alpha, interleukin 1 beta, and interferon gamma. Our results indicate that GlEV can exert preventive effects and possess therapeutic properties against DSS-induced colitis.

The positive rate of Clonorchis sinensis is the highest among intestinal parasites in the Republic of Korea (Korea). More than 1.2 million people were at risk of C. sinensis infection in Korea in 2012. An intensive control program is being implemented for residents of the 5 major river basins to reduce helminthic infections, including C. sinensis infection. This study evaluated the continuous intensive control program for parasitic diseases including clonorchiasis in areas near the 5 major river basins in Korea over the past 10 years (2011-2020). A total of 335,020 fecal samples (one sample per resident) prepared by the modified sedimentation technic were microscopically examined. Those who expelled helminth eggs were treated with anthelmintics through local health centers and re-examined 3 months later. The overall positive rate of helminths egg was 7.1%. The annual positive rates were dramatically decreased from 14.4% (2011) to 5.9% (2020). The egg positive rate was highest in C. sinensis (5.3%), followed by heterophyid flukes (1.5%) and Trichuris trichiura (0.2%). The prevalence of C. sinensis was significantly higher in males (7.6%) than in females (3.7%), and the highest in the 50–59 years (7.0%) age group. Our results are beneficial to establish prevention and control policies against helminthiases including clonorchiasis in endemic areas in this country.

Toxoplasma gondii ME49 infections are typically diagnosed by serological tests. However, serological diagnosis of RH strain-induced toxoplasmosis remains unknown. In order to develop seradiagnosis of above 2 kinds of infections, we generated recombinant virus-like particles (VLPs) displaying the T. gondii rhoptry protein 4 (ROP4) and evaluated their potential in T. gondii ME49 or RH strain infection diagnostics. Mice were orally infected with either the tachyzoites of T. gondii (RH) or cysts of T. gondii (ME49) at various dosages, and sera were collected at regular intervals. ELISA-based serological tests were performed to assess IgG, IgM, and IgA antibody responses against ROP4 VLP antigen and tissue lysate antigen (TLA). Compared to TLA, IgG, IgM, and IgA levels to ROP4 VLP antigen were significantly higher in the sera of T. gondii RH-infected mice 1 and 2 week post-infection (PI). T. gondii-specific IgG antibody was detected at 1, 2, 4, and 8 week PI in the T. gondii ME49-infected mice with infection dose-dependent manner. These results indicated that the ROP4 VLP antigen was highly sensitive antigens detecting T. gondii RH and ME49 antibodies at an early stage.

Purpose: To assess characteristics the application of mobile medication system and medication administration error (MAE) alerts in a general hospital. Methods: The subject hospital adopted a mobile medication system in 2016. All medication administrations in the general wards and ICUs were automatically recorded in real-time using identification barcodes, drug barcodes, and hand-held point-of-care devices. MAE alert logs were recorded from April 1st 2017 to March 31st 2018. For this study analysis was done using Pearson’s chi-squared test for potentially related factors of MAE alerts included administration time, order type, medication route, and length of nurse’s employment. Results: The total number of medications during the period of this study was 3,227,990. Among them, 2,698,317 medication doses were recorded, resulting in the system application rate of 83.6%. The system application rate was significantly correlated with all factors related to potential MAE alters. In this study 23,314 MAE alerts(0.9% of the total medication doses) were identified. The MAE alerts were related to new (OR=2.26, p<.001) and emergency (OR=2.25, p<.001) orders, and administration at a non-standard time (OR=2.032, p<.001). Medication route (p<.001), and nurse’s employment duration(p<.001) were also related. Conclusion A mobile medication system contributes to improving patient safety by preventing potential MAEs. The MAE alerts were related to administration time, order type, medication route, and duration of nurse’s employment. In order to prevent medication administration errors, it is necessary to standardize the process of medication and create an environment in which medication administration can be performed in a planned situation.

Purpose: The purpose of this study was to develop a motivation-enhanced self-management (MESM) intervention for irritable bowel syndrome (IBS) and to evaluate its effects on female college students with IBS. Methods: The program was constructed to reflect the conceptual framework of the self-determination theory including autonomous motivation enhancement strategy through the satisfaction of psychological needs. The experimental group (n=24) participated in the all eight weekly MESM sessions, and the control group (n=25) received one hour education of IBS. Primary outcome measures were the IBS symptom severity scale (IBS-SSS) and the IBS specific quality of life (IBS-QOL), and assessed at the baseline and at eight and 16 weeks after the allocation. Others were autonomous motivation, self-determined behavior, and psychological distress assessed at the baseline and at eight weeks. Results: The experimental group showed improvement in the IBS-SSS (p<.001) at 16 weeks compared to the control group. They showed markedly more improvement in the IBS QOL (p=.008), but the magnitude of this difference decreased at 16 weeks. The experimental group showed improvements in autonomous motivation (p=.035), self-determined behavior (p=.023), and psychological distress (p=.044) compared to the control group. Conclusion Study results suggest that the MESM intervention for female college students may effectively improve the IBS-SSS and the QOL.

Purpose: The purpose of this study was to describe changes in positive psychological capital, organizational commitment and burnout according to work periods for new nurses. Methods: A longitudinal study was done using surveys of 91 nurses from a tertiary hospital located in Seoul, South Korea. Data were collected from these newly graduated nurses during the period from July 2018 to September 2019, three times (2 months, 4 months and 6 months after starting to work). Results: Hope of positive psychological capital decreased after 6 months of work (F=7.11, p=.001) and organizational commitment decreased after 4 months of work (F=15.30, p<.001). Factors influencing participants' burnout included the optimism of positive psychological capital and continuance of organizational commitment. These factors explained 51.3% of the variance in burnout (F=48.47, p<.001). Conclusion Organizational support for new nurses is urgently needed. It is necessary to develop programs to strengthen the positive psychological capital of newly graduated nurses to reduce their burnout and to help their job adaptation.

Toxoplasma gondii can infect humans worldwide, causing serious diseases in pregnant women and immunocompromised individuals. T. gondii rhoptry protein 13 (ROP13) is known as one of the key proteins involved in host cell invasion. In this study, we generated virus-like particles (VLPs) vaccine expressing T. gondii rhoptry ROP13 and investigated VLPs vaccine efficacy in mice. Mice immunized with ROP13 VLPs vaccine elicited significantly higher levels of T. gondii-specific IgG, IgG1, IgG2a, and IgA antibody responses following boost immunization and challenge infection, whereas antibody inductions were insignificant upon prime immunization. Differing immunization routes resulted in differing antibody induction, as intranasal immunization (IN) induced greater antibody responses than intramuscular immunization (IM) after boost and challenge infection. IN immunization induced significantly higher levels of IgG and IgA antibody responses from feces, antibody-secreting cells (ASCs), CD4⁺ T, CD8⁺ T cells and germinal center B cell responses in the spleen compared to IM immunization. Compared to IM immunization, IN immunization resulted in significantly reduced cyst counts in the brain as well as lesser body weight loss, which contributed to better protection. All of the mice immunized through either route survived, whereas all naïve control mice perished. These results indicate that the ROP13 VLPs vaccine could be a potential vaccine candidate against T. gondii infection.
Animals ; Antibody Formation ; Antibody-Producing Cells ; Body Weight ; Brain ; Feces ; Female ; Germinal Center ; Humans ; Immunization ; Immunoglobulin A ; Immunoglobulin G ; Mice ; Pregnant Women ; Spleen ; T-Lymphocytes ; Toxoplasma