Love thy neighbor? The role of trust in neighbors during the COVID-19 crisis.

During a pandemic, trust can either promote cooperative behavior, as people pay attention to their actions toward other people's health, or hinder cooperative behavior by decreasing risk perception. By linking South Korea's Community Health Survey data with district-level statistics of the number of confirmed cases, I examine the effect of trust during the pre-pandemic period on district-level infection rates. I find that trust in neighbors is negatively associated with infection rates during the period when people are well aware of social distancing measures. Results of the individual-level analysis demonstrate that trust in neighbors is positively associated with the probability of implementing social distancing measures, particularly, those that are difficult to enforce. This finding implies that trust in neighbors increases people's motivation to cooperate voluntarily with public precautionary measures that can reduce the probability of infection.

Identification and characterization of microplastics in nasal irrigation fluids: A preliminary study.

KEY POINTS: Microplastics were identified in nasal irrigations Polypropylenes, which were the main component of the nozzle, were commonly identified Additional studies are needed to understand the biological relevance of microplastics in nasal irrigations.

Integrin ß1 regulates the perineural invasion and radioresistance of oral squamous carcinoma cells by modulating cancer cell stemness.

Perineural invasion and radioresistance are the main determinants of treatment outcomes in oral squamous cell carcinoma (OSCC), but the exact mechanism is still unknown. We conducted an in vitro experiment to evaluate the role of integrin ß1 (ITGB1) in the perineural invasion, radioresistance, and tumor aggressiveness of OSCC. Two OSCC cell lines (SCC25, SCC15) and radiation-induced radioresistant OSCC cell lines were used in this study. The expression of ITGB1 was compared between control radiosensitive and radioresistant OSCC cell lines. ITGB1 was inhibited by small hairpin RNA, and then the adhesion to neuronal cells, responsiveness to radiation, and aggressiveness of both OSCC cell lines were evaluated. Expression of ITGB1 and adhesion to neuronal cells were increased in radioresistant OSCC compared with control radiosensitive OSCC, and increased ITGB1 expression was more prominent in cancer stem cell-like cells. When the expression of ITGB1 was inhibited, the adhesion to neuronal cells, resistance to radiation, and invasion and migration of radioresistant OSCC were significantly reduced. Moreover, the expression of cancer stem cell markers and size of spheroid formations were also significantly attenuated by inhibiting ITGB1. These findings suggest that ITGB1 may be a significant contributor to perineural invasion and the maintenance of radioresistance in OSCC cells, and is associated with cancer stem cell-like cells. Furthermore, our results suggest a possible relationship between perineural invasion and radioresistance of OSCC. More detailed research is warranted to evaluate the role of ITGB1 as a novel emerging therapeutic target for radioresistant OSCC.

Detection of a novel porcine circovirus 4 in Korean pig herds using a loop-mediated isothermal amplification assay.

A novel porcine circovirus 4 has been recently identified in China and Korea. A sensitive and specific diagnostic method is urgently required to detect the virus in field samples. We developed a loop-mediated isothermal amplification (LAMP) the assay for the visual detection of PCV4 and evaluated its sensitivity, specificity, and applicability in clinical samples. This assay's results can be directly visualized by the naked eye using hydroxynaphthol blue after incubation for 40 min at 64 °C. The assay specifically amplified PCV4 DNA and no other viral nucleic acids. The sensitivity of the assay was <50 DNA copies/reaction, which was 10 times more sensitive than conventional polymerase chain reaction (cPCR) and comparable to real-time PCR (qPCR). Clinical evaluation revealed that the PCV4 detection rate in individual pig samples and at the farm level was 39.3 % (57/145) and 45.7 % (32/70), respectively, which were higher than cPCR (46 samples, 24 farms) and qPCR (52 samples, 29 farms) results. Cumulatively, owing to the advantages of high sensitivity and specificity, direct visual monitoring of the results, no possibility for cross-contamination, and being a low-cost equipment, the developed LAMP assay will be a valuable tool for the detection of the novel PCV4 in clinical samples, even in resource-limited laboratories.

A simple colorimetric detection of porcine epidemic diarrhea virus by reverse transcription loop-mediated isothermal amplification assay using hydroxynaphthol blue metal indicator.

A simple reverse transcription loop-mediated isothermal amplification combined with visual detection method (vRT-LAMP) assay was developed for rapid and specific detection of porcine epidemic diarrhea virus (PEDV) in this study, which overcomes the shortcomings of previously described RT-LAMP assays that require additional detection steps or pose a risk of cross-contamination. The assay results can be directly detected by the naked eye using hydroxynaphthol blue after incubating for 40 min at 62 °C. The assay specifically amplified PEDV RNA and no other viral nucleic acids. The limit of detection of the assay was less than 50 RNA copies per reaction, which was 100 times more sensitive than conventional reverse transcription polymerase chain reaction (RT-PCR) and comparable to real-time RT-PCR (RRT-PCR). In the clinical evaluation, the PEDV detection rate of vRT-LAMP was higher than that of RRT-PCR, showing 99 % concordance, with a kappa value (95 % confidence interval) of 0.97 (0.93-1.01). Considering the advantages of high sensitivity and specificity, simple and direct visual monitoring of the results, no possibility for cross-contamination, and being able to be used as low-cost equipment, the developed vRT-LAMP assay will be a valuable tool for detecting PEDV from clinical samples, even in resource-limited laboratories.

Association of the COVID-19 Pandemic and Low-rescue Suicide Attempts in Patients Visiting the Emergency Department after Attempting Suicide.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic may increase the total number of suicide attempts and the proportion of low-rescue attempts. We investigated the factors affecting low-rescue suicide attempts using the risk-rescue rating scale (RRRS) among patients who visited the emergency department (ED) after attempting suicide before or during the COVID-19 pandemic. METHODS: We retrospectively investigated suicide attempts made by patients who visited our ED from March 2019 to September 2020. Patients were classified into two groups based on whether they attempted suicide before or during the COVID-19 pandemic. Data on demographic variables, psychiatric factors, suicide risk factors and rescue factors were collected and compared. RESULTS: A total of 518 patients were included in the study, 275 (53.1%) of whom attempted suicide during the COVID-19 pandemic. The proportion of patients who made low-rescue suicide attempts differed before and during the COVID-19 pandemic (37.1% vs. 28.8%) (P = 0.046). However, the proportions of patients who made high-risk suicide attempts and high-lethality suicide attempts did not significantly differ between the two periods. The independent risk factors for low-rescue suicide attempts were age and the COVID-19 pandemic (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.00-1.03; P = 0.006) (OR, 1.52; 95% CI, 1.03-2.25; P = 0.034). CONCLUSION: The COVID-19 pandemic was associated with low-rescue suicide attempts in patients visiting the ED after attempting suicide. Thus, we need to consider the implementation of measures to prevent low-rescue suicide attempts during similar infectious disease crises.

Associations of Circulating Levels of Sphingosine 1-Phosphate with the Trabecular Bone Score and Bone Mineral Density in Postmenopausal Women.

Despite the potential roles of sphingosine 1-phosphate (S1P) as a biomarker of osteoporotic fracture (OF), independent of bone mineral density (BMD) and clinical risk factors (CRFs), its association with bone microarchitecture, a key determinant of bone quality, have not been studied yet. We here investigated the association of S1P with the trabecular bone score (TBS), an index of the bone microarchitecture. The plasma S1P concentrations, TBS, and BMD were measured in the 339 postmenopausal women. The S1P level was inversely correlated with the TBS (γ=-0.096, p=0.049) and BMD at the femur neck (FN-BMD: γ=-0.122, p=0.025) and tended to be inversely correlated the BMD at the total hip (TH-BMD: γ=-0.096, p=0.079), but not at the lumbar spine (LS-BMD). After adjusting for fracture risk assessment tool probabilities of major OF from CRFs, the S1P level was inversely associated with the TBS (ß=-0.096, p=0.049) and FN-BMD (ß=-0.118, p=0.025) and tended to be inversely associated with the TH-BMD (ß=-0.092, p=0.083). Compared with subjects in the lowest S1P tertile, those in the highest S1P tertile had a significantly lower TBS (p=0.032) and BMD at femur (p=0.004-0.036). These findings indicated that a high S1P level in postmenopausal women was inversely associated with the both bone mass and microarchitecture, reflecting the compromised bone strength.

Factors Affecting Collaborations between a Tertiary-level Emergency Department and Community-based Mental Healthcare Centers for Managing Suicide Attempts.

BACKGROUND: Community-based active contact and follow-up are known to be effective in reducing the risk of repeat suicide attempts among patients admitted to emergency departments after attempting suicide. However, the characteristics that define successful collaborations between emergency departments and community-based mental healthcare centers in this context are not well known. METHODS: This study investigated patients visiting the emergency department after suicide attempts from May 2017 to April 2019. Patients were classified in either the successful collaboration group or the failed collaboration group depending on whether or not they were linked to a community-based follow-up intervention. Clinical features and socioeconomic status were considered as independent variables. Logistic regression analysis was performed to identify factors influencing the collaboration. RESULTS: Of 674 patients, 153 (22.7%) were managed successfully via the targeted collaboration. Completion of hospital-based psychological counseling (adjusted odds ratio [aOR], 233.55; 95% confidence interval [CI], 14.99-3,637.67), supported out-of-pocket expenses (aOR, 11.17; 95% CI, 3.03-41.03), Korean Triage and Acuity Scale 1-3 (aOR, 4.31; 95% CI, 1.18-15.73), suicide attempt associated with mental disorder (aOR, 0.15; 95% CI, 0.04-0.52), and self-discharge against medical advice (aOR, 0.12; 95% CI, 0.02-0.70) were independent factors influencing the collaboration. CONCLUSION: Completion of hospital-based psychological counseling was the most highly influential factor determining the outcome of the collaboration between the emergency department and community-based mental healthcare center in the management of individuals who had attempted suicide. Completion of hospital-based psychological counseling is expected to help reduce the risk of repeat suicide attempts.

High Circulating Sphingosine 1-Phosphate is a Risk Factor for Osteoporotic Fracture Independent of Fracture Risk Assessment Tool.

Circulating sphingosine 1-phosphate (S1P) levels may be a biomarker for osteoporotic fracture (OF). This study assessed whether the addition of S1P levels to the fracture risk assessment tool (FRAX) could improve predictability of OF risk. Plasma S1P concentrations and FRAX variables were measured in 81 subjects with and 341 subjects without OF. S1P levels were higher in subjects with than those without OF (3.11 ± 0.13 µmol/L vs. 2.65 ± 0.61 µmol/L, P = 0.001). Higher S1P levels were associated with a higher likelihood of OF (odds ratio [OR] = 1.33, 95% confidence interval [CI] = 1.05-1.68), even after adjusting for FRAX probabilities. Compared with the lowest S1P tertile, subjects in the middle (OR = 3.37, 95% CI = 1.58-7.22) and highest (OR = 3.65, 95% CI = 1.66-8.03) S1P tertiles had higher rates of OF after adjustment. The addition of S1P levels to FRAX probabilities improved the area under the receiver-operating characteristics curve (AUC) for OF, from 0.708 to 0.769 (P = 0.013), as well as enhancing category-free net reclassification improvement (NRI = 0.504, 95% CI = 0.271-0.737, P < 0.001) and integrated discrimination improvement (IDI = 0.044, 95% CI = 0.022-0.065, P < 0.001). Adding S1P levels to FRAX probabilities especially in 222 subjects with osteopenia having a FRAX probability of 3.66-20.0% markedly improved the AUC for OF from 0.630 to 0.741 (P = 0.012), as well as significantly enhancing category-free NRI (0.571, 95% CI = 0.221-0.922, P = 0.001) and IDI (0.060, 95% CI = 0.023-0.097, P = 0.002). S1P is a consistent and significant risk factor of OF independent of FRAX, especially in subjects with osteopenia and low FRAX probability.

Advanced target-specific probe-based real-time loop-mediated isothermal amplification assay for the rapid and specific detection of porcine circovirus 3.

Porcine circovirus type 3 (PCV3) is an emerging viral pathogen that has been identified in pigs with various clinical signs. For rapid and specific detection of PCV3, an advanced real-time loop-mediated isothermal amplification (rLAMP) assay that uses both assimilating probes and swarm primers were developed and evaluated in this study. The assay specifically amplified PCV3 DNA, but it did not amplify other porcine viral nucleic acids. The limit of detection of rLAMP with swarm primers was 50 PCV3 DNA copies/reaction, which was comparable to that of the real-time quantitative polymerase chain reaction (qPCR) and 10 times more sensitive than rLAMP without swarm primers. In an evaluation of clinical samples, the rLAMP assay was able to detect PCV3 DNA within 17.34 ± 4.45 min, which is more rapid than what has been previously reported for the standard qPCR assay (31.78 ± 4.60 min). Detection with rLAMP was largely in agreement with that of the qPCR with a kappa value (95% confidence interval) of 0.98 (0.95-1.00). Taken together, these results suggest that the rLAMP assay presented will be a valuable tool for rapid, specific and reliable diagnosis of PCV3 in clinical samples.

Genetic characterization of canine parvovirus type 2c from domestic dogs in Korea.

Canine parvovirus type 2 (CPV-2) is an aetiological agent that causes acute haemorrhagic enteritis and fatal myocarditis in dogs. Since CPV-2 first emerged in the late 1970s, its rapid evolution has resulted in three antigenic variants: CPV-2a, CPV-2b and CPV-2c. Here, we report, for the first time in Korea, two cases of CPV-2c infection in two dogs with severe diarrhoea. The complete open reading frame (4,269nt) of CPV-2, encoding both non-structural (NS) and structural (VP) proteins, was sequenced. Based on the amino acid Gln present at residue 426 of the VP2 gene, these strains were typed as CPV-2c, and were named Korea CPV-2c_1 and Korea CPV-2c_2. These strains shared 99.48% reciprocal nucleotide sequence identity and had the highest nucleotide identity (99.77%-99.34%) with Asian CPV strains isolated in China, Italy (found in a dog imported from Thailand), and Vietnam from 2013 to 2017. Phylogenetic analysis based on the non-structural (NS1) and capsid (VP2) genes revealed that Korean CPV-2c strains clustered closely to Asian CPV strains, and separately from strains isolated in Europe, South America and North America. Amino acid changes never reported before were observed in NS1 (Thr70Pro, Cys287Tyr), VP1 (Lys17Arg, Phe33Leu) and VP2 (Gln365His, Ala516Val). Additional observed mutations, including Phe267Tyr, Tyr324Ile and Gln370Arg, have been previously reported in the recent CPV-2c strains with Asian origins. These results suggest that the Korean CPV-2c strains were potentially introduced via neighbouring Asian countries.

[The Influence of Grit on Turnover Intention of University Hospital Nurses: The Mediating Effect of Job Involvement].

PURPOSE: This study aimed to confirm the mediating effect of job involvement in the relationship between grit and turnover intention among nurses working at university hospitals. METHODS: Participants included 437 nurses from university hospitals located in C city, Gyeongnam. Data were collected from January 8 to 19, 2018, using self-report questionnaires. Data were analyzed using the t-test, analysis of variance, Scheffe's test, Pearson's correlation coefficient, and multiple regression, with the SPSS/22.0 program. A mediation analysis was performed according to the Baron and Kenny, and bootstrapping methods. RESULTS: There were significant relationships between grit and job involvement (r=.40, p<.001), grit and turnover intention (r=-.29, p<.001), and turnover intention and job involvement (r=-.52, p<.001). Job involvement showed partial mediating effects in the relationship between grit and turnover intention. CONCLUSION: Grit increased job involvement and lowered turnover intention. Therefore, to reduce nurses' turnover intention, it is necessary to develop a program and strategies to increase their grit.

Differential detection of porcine reproductive and respiratory syndrome virus genotypes by a fluorescence melting curve analysis using peptide nucleic acid probe-mediated one-step real-time RT-PCR.

Peptide nucleic acids (PNAs), artificially synthesized DNA analogues, hybridize strongly with DNA and are useful for fluorescence melting curve analyses (FMCA) based on the thermal denaturation of the probe-target duplex. In this study, we developed a PNA-based one-step real-time RT-PCR assay for the differential and qualitative detection of the porcine reproductive and respiratory syndrome virus genotypes PRRSV1 and PRRSV2. The specificity of the assay was analyzed in silico using previously reported primers and probes and was subsequently verified using Korean PRRSV panels and clinical samples. Seven clinical samples showing low curves with high Ct values were confirmed as negative by FMCA. The sensitivities of one-step real-time PCR for PRRSV1 and PRRSV2 were 15 and 11 copies, respectively, and the results were in 100% agreement with those of conventional RT-PCR combined with nested PCR using clinical samples. Therefore, the assay is highly specific for the detection of current PRRSV1 and PRRSV2 without non-specific amplification by FMCA.

Correction to: Characteristics of single ocular motor nerve palsy associated with anti-GQ1b antibody.

The original version of this article unfortunately contained a mistake.

Compositional data analysis and geochemical modeling of CO2-water-rock interactions in three provinces of Korea.

The CO2-rich spring water (CSW) occurring naturally in three provinces, Kangwon (KW), Chungbuk (CB), and Gyeongbuk (GB) of South Korea was classified based on its hydrochemical properties using compositional data analysis. Additionally, the geochemical evolution pathways of various CSW were simulated via equilibrium phase modeling (EPM) incorporated in the PHREEQC code. Most of the CSW in the study areas grouped into the Ca-HCO3 water type, but some samples from the KW area were classified as Na-HCO3 water. Interaction with anorthite is likely to be more important than interaction with carbonate minerals for the hydrochemical properties of the CSW in the three areas, indicating that the CSW originated from interactions among magmatic CO2, deep groundwater, and bedrock-forming minerals. Based on the simulation results of PHREEQC EPM, the formation temperatures of the CSW within each area were estimated as 77.8 and 150 °C for the Ca-HCO3 and Na-HCO3 types of CSW, respectively, in the KW area; 138.9 °C for the CB CSW; and 93.0 °C for the GB CSW. Additionally, the mixing ratios between simulated carbonate water and shallow groundwater were adjusted to 1:9-9:1 for the CSW of the GB area and the Ca-HCO3-type CSW of the KW area, indicating that these CSWs were more affected by carbonate water than by shallow groundwater. On the other hand, mixing ratios of 1:9-5:5 and 1:9-3:7 were found for the Na-HCO3-type CSW of the KW area and for the CSW of the CB area, respectively, suggesting a relatively small contribution of carbonate water to these CSWs. This study proposes a systematic, but relatively simple, methodology to simulate the formation of carbonate water in deep environments and the geochemical evolution of CSW. Moreover, the proposed methodology could be applied to predict the behavior of CO2 after its geological storage and to estimate the stability and security of geologically stored CO2.

Uncaria rhynchophylla ameliorates amyloid beta deposition and amyloid beta-mediated pathology in 5XFAD mice.

One of the pathological hallmarks of Alzheimer's disease (AD) is the abnormal aggregation of amyloid beta (Aß) peptides. Uncaria rhynchophylla (UR), one of the Uncaria species, has long been used to treat neurodegenerative disease. In particular, it has been reported that UR inhibits aggregation of Aß in vitro. However, little is known about the histological effects of UR treatment on Aß pathology in AD animal models. In the present study, we investigated the effect of UR on Aß aggregation, Aß-mediated pathologies and adult hippocampal neurogenesis in the brain of 5XFAD mice. First, using the thioflavin T assay and amyloid staining, we demonstrated that UR treatment effectively inhibited Aß aggregation and accumulation in the cortex and subiculum. Second, immunofluorescence staining showed that administration of UR attenuated gliosis and neurodegeneration in the subiculum and cortex. Third, UR treatment ameliorated impaired adult hippocampal neurogenesis. The present results indicate that UR significantly alleviates Aß deposition and Aß-mediated neuropathology in the brain in 5XFAD mice, suggesting the potency of UR as a preventive and therapeutic agent for AD.

Detection and genetic characterization of porcine circovirus 3 from aborted fetuses and pigs with respiratory disease in Korea.

A novel porcine circovirus 3 (PCV3) was first detected in pigs showing porcine dermatitis and nephropathy syndrome, reproductive failure, and multisystemic inflammation in the USA. Herein, we report on PCV3 as a potential etiological agent of clinical signs, reproductive failure and respiratory distress on Korean pig farms, based on in situ hybridization, pathological, and molecular findings. Confirmation of the presence of PCV3 may increase co-infection with other causative agents of disease in Korean pig herds, indicating the need for further systemic investigation of pathogenicity and of multiple infections with PCV2 genotypes and bacteria, and the development of an effective PCV3 vaccine.

Isolation and characterization of Korean porcine deltacoronavirus strain KNU16-07.

Porcine deltacoronavirus (PDCoV) has emerged in several pig-raising countries and has been a causative pathogen associated with diarrheal diseases in South Korea since 2014. In the present study, we were able to isolate and cultivate a Korean PDCoV strain (KNU16-07) in cell culture and investigate its pathogenicity. PDCoV-inoculated piglets showed watery diarrhea accompanied by acute enteritis in the natural host. Sequencing analysis demonstrated the genetic stability of KNU16-07 for at least thirty serial passages.

Postoperative outcomes of natural orifice transluminal endoscopic surgery-assisted vaginal hysterectomy and conventional laparoscopic-assisted vaginal hysterectomy: a comparative study.

OBJECTIVE: The present study aimed to determine the differences in outcomes between natural orifice transluminal endoscopic surgery-assisted vaginal hysterectomy (NAVH) and conventional laparoscopy-assisted vaginal hysterectomy (LAVH). METHODS: We retrospectively reviewed the charts of patients who between July 2012 and September 2015, were diagnosed as having benign uterine disease such as uterine myoma, endometriosis, or adenomyosis and managed via NAVH or LAVH in a single-center (Eulji University Hospital). Data such as age, body weight, height, parity, operation time, intra/post-operative complications, and uterus weight were obtained from the clinical charts. NAVH and LAVH recipients were matched 1:3 in terms of baseline characteristics, and the 2 groups were compared regarding surgical outcomes. RESULTS: Of the 160 patients with benign uterine disease included in the present study. Forty received NAVH and remaining 120 received LAVH. There were significant differences between the groups regarding operation time and hemoglobin change. Notably, although the operation time was shorter for LAVH, hemoglobin change was lower for NAVH. Additionally, although maximum hospitalization duration was shorter for LAVH, the average length of hospitalization was similar between NAVH and LAVH. There were no significant differences between the groups in terms of other variables. CONCLUSION: NAVH may become a new alternative surgical method of choice for hysterectomy, as it represents a clinically feasible and safe approach; moreover is superior to LAVH in terms of bleeding loss.

Loop-mediated isothermal amplification assay for the rapid and visual detection of novel porcine circovirus 3.

A loop-mediated isothermal amplification (LAMP) assay using hydroxynaphthol blue was developed for the rapid and visual detection of the capsid gene of porcine circovirus 3 (PCV3). The amplification could be completed in 40 min at 62°C, and the results could be visually detected by the naked eye. The assay specifically amplified PCV3 DNA and not other porcine viral nucleic acids. The limit of detection of the assay was 50 PCV3 DNA copies, which was comparable to that of the real-time polymerase chain reaction (qPCR) and lower than that of conventional PCR. In the clinical evaluation, the PCV3 detection rate of the LAMP assay was higher than that of PCR and agreed 100% with that of qPCR. These results indicate that the LAMP assay will be a valuable tool for the rapid, sensitive, and specific detection of PCV3 in clinical samples.