European and US Guideline-Based Statin Eligibility, Genetically Predicted Coronary Artery Disease, and the Risk of Major Coronary Events

BACKGROUND

A study was designed to investigate whether the coronary artery disease polygenic risk score (CAD-PRS) may guide lipid-lowering treatment initiation as well as deferral in primary prevention beyond established clinical risk scores.

METHODS AND RESULTS

Participants were 311 799 individuals from the UK Biobank free of atherosclerotic cardiovascular disease, diabetes, chronic kidney disease, and lipid-lowering treatment at baseline. Participants were categorized as statin indicated, statin indication unclear, or statin not indicated as defined by the European and US guidelines on statin use. For a median of 11.9 (11.2-12.6) years, 8196 major coronary events developed. CAD-PRS added to European-Systematic Coronary Risk Evaluation 2 (European-SCORE2) and US-Pooled Cohort Equation (US-PCE) identified 18% and 12% of statin-indication-unclear individuals whose risk of major coronary events were the same as or higher than the average risk of statin-indicated individuals and 16% and 12% of statin-indicated individuals whose major coronary event risks were the same as or lower than the average risk of statin-indication-unclear individuals. For major coronary and atherosclerotic cardiovascular disease events, CAD-PRS improved C-statistics greater among statin-indicated or statin-indication-unclear than statin-not-indicated individuals. For atherosclerotic cardiovascular disease events, CAD-PRS added to the European evaluation and US equation resulted in a net reclassification improvement of 13.6% (95% CI, 11.8-15.5) and 14.7% (95% CI, 13.1-16.3) among statin-indicated, 10.8% (95% CI, 9.6-12.0) and 15.3% (95% CI, 13.2-17.5) among statin-indication-unclear, and 0.9% (95% CI, 0.6-1.3) and 3.6% (95% CI, 3.0-4.2) among statin-not-indicated individuals.

CONCLUSIONS

CAD-PRS may guide statin initiation as well as deferral among statin-indication-unclear or statin-indicated individuals as defined by the European and US guidelines. CAD-PRS had little clinical utility among statin-not-indicated individuals.

Etiological agent and clinical characteristics of haemorrhagic fever with renal syndrome in the southern Republic of Korea: a genomic surveillance study

OBJECTIVES

High incidences of haemorrhagic fever with renal syndrome (HFRS) have been reported in the southern Republic of Korea (ROK). A distinct southern genotype of Orthohantavirus hantanense (HTNV) was identified in Apodemus agrarius chejuensis on Jeju Island. However, its association with HFRS cases in southern ROK remains elusive. We investigated the potential of the southern HTNV genotype as an etiological agent of HFRS.

METHODS

Samples from 22 patients with HFRS and 193 small mammals were collected in the southern ROK. The clinical characteristics of patients infected with the southern HTNV genotype were analysed. Amplicon-based MinION sequencing was employed for southern HTNV from patients and rodents, facilitating subsequent analyses involving phylogenetics and genetic reassortment.

RESULTS

High-throughput sequencing of HTNV exhibited higher coverage with a cycle of threshold value below 32, acquiring nearly whole-genome sequences from six patients with HFRS and seven A. agrarius samples. The phylogenetic pattern of patient-derived HTNV demonstrated genetic clustering with HTNV from Apodemus species on Jeju Island and the southern Korean peninsula, revealing genetic reassortment in a single clinical sample between the M and S segments.

DISCUSSION

These findings imply that the southern HTNV genotype has the potential to induce HFRS in humans. The phylogenetic inference demonstrates the diverse and dynamic characteristics of the southern HTNV tripartite genomes. Therefore, this study highlights the significance of active surveillance and amplicon sequencing for detecting orthohantavirus infections. It also raises awareness and caution for physicians regarding the emergence of a southern HTNV genotype as a cause of HFRS in the ROK.

Persistent Positive Real-Time Reverse Transcription Polymerase Chain Reaction (RT-PCR) Results in Recovered COVID-19 Hospital Patients: Implications for Interpretation

Background Real-time reverse transcription polymerase chain reaction (RT-PCR) test results often remain positive in patients with COVID-19, even after their symptoms have improved. We compared the characteristics of patients with persistently positive RT-PCR test results despite improved COVID-19 symptoms to those whose RT-PCR test results turned negative following symptom improvement. Materials and methods A total of 143 adult patients with COVID-19 who were hospitalized at a tertiary university hospital were enrolled. Demographic, clinical, treatment, and epidemiological data were extracted from their electronic medical records. These data were compared between patients with persistently positive RT-PCR test results and those with negative RT-PCR test results after symptom improvement. Results The prevalence of cough and respiratory symptoms was less in COVID-19 patients with persistently positive RT-PCR test results after symptom improvement than in other patients with COVID-19 (p<0.05). Conclusion Persistently positive patients had a lower prevalence of cough than those who became negative. None of the other examined co-variates (hypertension, chronic kidney disease, chronic lung disease, dyslipidemia, etc.) was associated with the persistent positivity.

Subzero saline chilling with or without prechilling in icy water improved chilling efficiency and meat tenderness of broiler carcasses

Freshly slaughtered carcasses need to be chilled to improve product quality, meat safety, and processing efficiency. This research investigated the effect of subzero saline chilling (SSC) on broiler carcasses with or without prechilling in icy water. Water immersion chilling at 0.5°C (WIC) or SSC at 4% NaCl/-2.41°C (SSC) was a major chilling step. For the combination of pre- and postchilling, the warm water immersion chilling (WWIC) at 10°C was used as prechilling and the WIC as postchilling (WWIC-WIC), and WIC was used as prechilling and the SSC as postchilling (WIC-SSC). The internal temperature of breast fillets was monitored during chilling. Carcasses in a prechiller were transported to a postchiller when their internal temperature reached 15°C. Chilling was completed when the carcass temperature reached 4.4°C or below, and breast fillets were harvested at 3-h postmortem to measure the pH and sarcomere length. Color (L*, a*, and b*) values were evaluated on both breast skin and skinless breast surfaces. Meat tenderness was evaluated using the breast fillets after overnight storage and cooking to an internal temperature of 76°C. The carcasses in the SSC and WIC-SSC showed shorter chilling times (85-91 min) than those (100-144 min) of WIC and WWIC-WIC. A higher chilling yield was observed for the carcasses in WIC-SSC, and a lower cooking yield was seen for the carcasses in WWIC-WIC than other chilling methods (P < 0.05). The breast fillets of broilers in the SSC and WIC-SSC showed lower shear forces and longer sarcomere length than the WIC and WWIC-WIC. No difference was found for L* and a* values, while lower b* value was observed in the SSC than the other chilling methods (P < 0.05). Based on these results, chilling of broiler carcasses in the SSC (4% NaCl/-2.41°C) with or without prechilling in WIC at 0.5°C significantly improved chilling efficiency and meat tenderness, with minor color changes on carcasses.

Coinfection With Severe Fever With Thrombocytopenia Syndrome and Scrub Typhus in Korea

Background

Scrub typhus and severe fever with thrombocytopenia syndrome (SFTS) are the 2 most common tick-borne infectious diseases in Korea. Every year, an increasing number of cases are reported, which is a public health concern. Therefore, we aimed to investigate the prevalence of SFTS-scrub typhus coinfection in patients with SFTS.

Methods

Clinical samples were collected from 129 patients with SFTS. One-step reverse-transcription polymerase chain reaction (PCR) was performed to identify the SFTS virus (SFTSV), and real-time PCR followed by nested PCR was performed to detect the Orientia tsutsugamushi gene for scrub typhus. Phylogenetic analysis was conducted to confirm the evolutionary relationships among different species.

Results

Among 129 SFTS cases, 2 patients with SFTSV were positive for O. tsutsugamushi with a prevalence of coinfection of 1.6% (95% confidence interval, .001-.06). Phylogenetic analysis confirmed these as O. tsutsugamushi strain Boryong.

Conclusions

Our study found that 1.6% of patients were coinfected with SFTS and scrub typhus infection. We believe that this information will add a new dimension to clinical diagnosis, which should be considered for better public health management. Further research is needed to better understand the ecological transmission dynamics and geographical distribution of SFTSV and O. tsutsugamushi in endemic countries.

Coxiella burnetii infection in a patient with tick bite

INTRODUCTION

We report the case of a 60-year-old male who was hospitalized with fever, headache, fatigue, nausea, and myalgia for six days.

METHODOLOGY

Polymerase chain reactions (PCR) were performed on patient blood samples, and four ticks were collected from the area the patient mowed. Indirect immunofluorescence assays (IFAs) were performed on serum samples to detect specific antibodies.

RESULTS

The collected ticks were identified as Haemaphysalis longicornis. Coxiella species-specific nested PCR (N-PCR) and sequencing confirmed the presence of Coxiella burnetii in the patient, and Coxiella-like bacteria were identified in three of the four ticks. IFA results showed ≥ 4-fold increases in both IgM and IgG antibody titers against Q fever.

CONCLUSIONS

Despite positive PCR results for Coxiella species in both the patient and the ticks, different bacterial species were isolated, suggesting that the patient was not infected with C. burnetii through tick bites. Further investigation is required to identify the carriers or transmitters of the infection.

Closed-loop cathode recycling in solid-state batteries enabled by supramolecular electrolytes

Deconstructing solid-state batteries (SSBs) to physically separated cathode and solid-electrolyte particles remains intensive, as does the remanufacturing of cathodes and separators from the recovered materials. To address this challenge, we designed supramolecular organo-ionic (ORION) electrolytes that are viscoelastic solids at battery operating temperatures (-40° to 45°C) yet are viscoelastic liquids above 100°C, which enables both the fabrication of high-quality SSBs and the recycling of their cathodes at end of life. SSBs implementing ORION electrolytes alongside Li metal anodes and either LFP or NMC cathodes were operated for hundreds of cycles at 45°C with less than 20% capacity fade. Using a low-temperature solvent process, we isolated the cathode from the electrolyte and demonstrated that refurbished cells recover 90% of their initial capacity and sustain it for an additional 100 cycles with 84% capacity retention in their second life.

Evaluation of humoral immune response in relation to COVID-19 severity over 1 year post-infection: critical cases higher humoral immune response than mild cases

Introduction

Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2. We investigated the antibody response against SARS-CoV-2 until 1 year after symptom onset.

Methods

We collected 314 serum samples from 97 patients with COVID-19. Antibody responses were tested using an indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and plaque reduction neutralization test (PRNT) to detect specific neutralizing antibodies.

Results

The positivity rates for neutralizing antibodies at a 1:10 titer cutoff were 58.1% at 1 week, 97.8% at 4 weeks, and 78% at 1 year after symptom onset (53.8% in asymptomatic patients and 89.3% in symptomatic patients). The IFA and anti-S1 ELISA IgG results significantly correlated with neutralizing antibody titers. Critical/fatal cases showed significantly higher antibody titers than the asymptomatic or mild-to-moderate illness groups. Nonetheless, the median number of days to the seroconversion of neutralizing antibodies was 10 and 15 in asymptomatic and symptomatic patients, respectively. The asymptomatic group had a significantly higher neutralizing potency index than the mild-to-severe illness groups.

Conclusions

Neutralizing antibodies corresponded to earlier seroconversion but had a shorter presence in the asymptomatic group than in the symptomatic group and were still present 1 year after symptom onset in critical/fatal cases.

SARS-CoV-2 RNAemia and Disease Severity in COVID-19 Patients

OBJECTIVE

The clinical implications of SARS-CoV-2 RNA viremia in blood (RNAemia) remain uncertain despite gaining more prognostic implications for coronavirus disease 2019 (COVID-19). However, the clinical relevance of SARS-CoV-2 RNAemia has not been well documented.

METHODS

We conducted a cohort study on 95 confirmed COVID-19 patients and explored the prospects with evidence of SARS-CoV-2 RNAemia in association with various clinical characteristics. We performed reverse transcription-polymerase chain reaction and studied the risk factors of SARS-CoV-2 RNAemia using logistic regression analysis.

RESULTS

The presence of SARS-CoV-2 RNAemia in critical or fatal cases was the highest (66.7%), followed by severe (12.5%) and mild to moderate (1.7%) in admission samples. SARS-CoV-2 viral RNAemia was detected on admission and 1st week samples; however, RNAemia was not detected on the samples collected on the second week post-symptom onset. Multiple regression analysis showed that the severity of the disease was an independent predictor of RNAemia (p < 0.021), and the Kaplan-Meier survival curve estimated an increased mortality rate in SARS-CoV-2 RNAemia cases (p < 0.001).

CONCLUSIONS

Our study demonstrated that SARS-CoV-2 RNAemia is a predictive risk factor for clinical severity in COVID-19 patients. Hence, we showed that blood RNAemia might be a critical marker for disease severity and mortality.

Comparison of Fusion, Subsidence, and Clinical Results Between 3D-Printed Porous Titanium Cage and Polyetheretherketone (PEEK) Cage in Posterior Lumbar Interbody Fusion: A Minimum of 2-years follow-up

OBJECTIVES

Early osteointegration and reduced modulus of elasticity has been proven with 3D-printed porous titanium (3DP-titanium) cage used for posterior lumbar interbody fusion (PLIF). The present study was conducted to demonstrate fusion rate, subsidence, and clinical outcome of the 3DP-titanium cage in PLIF and to compare its results with those of polyetheretherketone (PEEK) cage METHODS: A total of 150 patients who underwent 1-2 level PLIF and were followed-up for more than 2 years were retrospectively reviewed. Fusion rates, subsidence, segmental lordosis, back pain visual analogue scale (VAS), leg pain VAS, and Owestry disability index (ODI) were assessed.

RESULTS

Higher 1-year (3DP-titanium, 86.9%; PEEK, 67.7%; p=0.002) and 2-years (3DP-titanium, 92.9%; PEEK, 82.3%; p=0.037) fusion rate could be achieved with using 3DP-titanium cages for PLIF compared to PEEK cages. Amount of subsidence (3DP-titanium, 1.4±1.6mm; PEEK, 1.9±1.8mm; p=0.092) and incidence of significant subsidence (3DP-titanium, 17.9%; PEEK, 23.4%; p=0.389) was not significantly different between the two materials. Furthermore, back pain/leg pain VAS and ODI also was not significantly different between the two groups. In logistic regression analysis, cage material (p=0.027) showed significant association with fusion while number of levels fused (p=0.012) was associated with subsidence.

CONCLUSION

The 3DP-titanium cage resulted in a higher fusion rate than the PEEK cage when applied for PLIF. The subsidence rate did not differ significantly between the two cage materials. Therefore, the 3DP-titanium cage can be safely applied for PLIF, considering its stable construct.

Current Status of Q Fever and the Challenge of Outbreak Preparedness in Korea: One Health Approach to Zoonoses

Human Q fever, a zoonosis caused by Coxiella burnetii, presents with diverse clinical manifestations ranging from mild self-limited febrile illnesses to life-threatening complications such as endocarditis or vascular infection. Although acute Q fever is a benign illness with a low mortality rate, a large-scale outbreak of Q fever in the Netherlands led to concerns about the possibility of blood transfusion-related transmission or obstetric complications in pregnant women. Furthermore, a small minority (< 5%) of patients with asymptomatic or symptomatic infection progress to chronic Q fever. Chronic Q fever is fatal in 5-50% of patients if left untreated. In South Korea, Q fever in humans was designated as a notifiable infectious disease in 2006, and the number of Q fever cases has increased sharply since 2015. Nonetheless, it is still considered a neglected and under-recognized infectious disease. In this review, recent trends of human and animal Q fever in South Korea, and public health concerns regarding Q fever outbreaks are reviewed, and we consider how a One Health approach could be applied as a preventive measure to prepare for zoonotic Q fever outbreaks.

Clinical utility of universal 16S rRNA PCR using sterile body fluids: lung abscess caused by Nocardia farcinica

Nocardiosis is an infectious disease caused by Gram-positive rod-shaped bacteria and presents as a suppurative granulomatous disease in patients with compromised immune systems. Few studies have investigated the clinical utility of the universal 16S rRNA polymerase chain reaction (PCR) method using sterile body fluids for diagnosing nocardiosis. A 64-year-old female patient was admitted to Chosun University Hospital with the complaint of fever. Computed tomography scans of her chest revealed the presence of empyema and an abscess in the right lung. Pus samples were collected using closed chest thoracostomy and were cultured. The results revealed the presence of Gram-positive bacilli, but the culture tests were unable to identify the causative microorganism. Despite antibiotic treatment, the patient died of the suspected empyema and abscess. Universal 16S PCR of her sterile body fluids in combination with sequencing was performed, which led to the diagnosis of Nocardia farcinica infection. Postmortem, the remainder of the pus samples cultured for 8 days confirmed the presence of N. farcinica. This study illustrates the importance of using routine universal 16S rRNA PCR with sterile body fluids to help diagnose atypical bacterial infections such as nocardiosis.

Cell selectivity and antibiofilm and anti-inflammatory activities and antibacterial mechanism of symmetric-end antimicrobial peptide centered on D-Pro-Pro

This study aimed to develop a new symmetric-end antimicrobial peptide (AMP) with cell selectivity, antibiofilm, and anti-inflammatory activities. Two symmetric-end AMPs, Lf6-pP and Lf6-GG, were designed based on the sequence RRWQWRzzRWQWRR, which contains two symmetric repeat sequences connected by a β-turn-promoting sequence (zz) that can be a rigid turn by D-Pro-Pro (pP) or a flexible turn by Gly-Gly (GG). Both Lf6-pP and Lf6-GG exhibited potent antibacterial activity without causing hemolysis, but Lf6-pP exhibited better cell selectivity, likely due to the more significant impact of the rigid pP turn. Compared to Lf6-GG, Lf6-pP demonstrated approximately three times higher antimicrobial activity against drug-resistant bacteria, had a low incidence of drug resistance, and maintained its activity in the presence of physiological salts and human serum. Additionally, Lf6-pP was more effective than Lf6-GG in inhibiting biofilm formation and eradicating mature biofilms. The BODIPY-cadaverine assay indicated that the potent anti-inflammatory activity of Lf6-pP may be attributed to its direct interaction with LPS, resulting in decreased TNF-α and IL-6 levels in LPS-stimulated macrophages. Mechanistic studies, including membrane depolarization, outer/inner membrane permeation, and membrane integrity change, demonstrated that Lf6-pP exerts its antibacterial action through an intracellular-target mechanism. Overall, we propose that Lf6-pP has potential as a novel antibacterial, antibiofilm, and anti-inflammatory agent against drug-resistant bacterial infections.

Boosting Thermal Conductivity by Surface Plasmon Polaritons Propagating along a Thin Ti Film

We experimentally demonstrate boosted in-plane thermal conduction by surface plasmon polaritons (SPPs) propagating along a thin Ti film on a glass substrate. Due to the lossy nature of metal, SPPs can propagate over centimeter-scale distances even along a supported metal film, and the resulting ballistic heat conduction can be quantitatively validated. Further, for a 100-nm-thick Ti film on a glass substrate, a significant enhancement of in-plane thermal conductivity compared to bulk value (∼25%) is experimentally shown. This Letter will provide a new avenue to employ SPPs for heat dissipation along a supported thin film, which can be readily applied to mitigate hot-spot issues in microelectronics.

Clinically differential diagnosis of human granulocytic anaplasmosis and severe fever with thrombocytopenia syndrome

This study analyzed HGA and SFTS in patients with suspected tick-borne infection by focusing on key differences that clinicians can easily recognize. A retrospective analysis was performed on confirmed patients with HGA or SFTS in 21 Korean hospitals from 2013 to 2020. A scoring system was developed by multivariate regression analysis and accuracy assessment of clinically easily discriminable parameters was performed. The multivariate logistic regression analysis revealed that sex (especially male sex) (odds ratio [OR] 11.45, P = 0.012), neutropenia (< 1500) (OR 41.64, P < 0.001), prolonged activated partial thromboplastin time (OR 80.133, P < 0.001), and normal C-reactive protein concentration (≤ 1.0 mg/dL; OR 166.855, P = 0.001) were significantly associated with SFTS but not with HGA. Each factor, such as meaningful variables, was given 1 point, and a receiver-operating characteristic curve with a cutoff value (> 1) in a 5-point scoring system (0-4 points) was analyzed to evaluate the accuracy of differentiation between HGA and SFTS. The system showed 94.5% sensitivity, 92.6% specificity, and an area under the receiver-operating characteristic curve of 0.971 (0.949-0.9). Where HGA and SFTS are endemic, the scoring system based on these four parameters such as sex, neutrophil count, activated partial thromboplastin time, and C-reactive protein concentration will facilitate the differential diagnosis of HGA and SFTS in the emergency room in patients with suspected tick-borne infectious diseases.

Efficacy of Plant-Made Human Recombinant ACE2 against COVID-19 in a Golden Syrian Hamster Model

Coronavirus disease 2019 (COVID-19) is a novel infectious respiratory disease caused by SARS-CoV-2. We evaluated the efficacy of a plant-based human recombinant angiotensin-converting enzyme 2 (hrACE2) and hrACE2-foldon (hrACE2-Fd) protein against COVID-19. In addition, we analyzed the antiviral activity of hrACE2 and hrACE2-Fd against SARS-CoV-2 using real-time reverse-transcription PCR and plaque assays. The therapeutic efficacy was detected using the Golden Syrian hamster model infected with SARS-CoV-2. Both hrACE2 and hrACE2-Fd inhibited SARS-CoV-2 by 50% at concentrations below the maximum plasma concentration, with EC₅₀ of 5.8 μg/mL and 6.2 μg/mL, respectively. The hrACE2 and hrACE2-Fd injection groups showed a tendency for decreased viral titers in nasal turbinate tissues on day 3 after virus inoculation; however, this decrease was not detectable in lung tissues. Histopathological examination on day 9 after virus inoculation showed continued inflammation in the SARS-CoV-2 infection group, whereas decreased inflammation was observed in both the hrACE2 and hrACE2-Fd injection groups. No significant changes were observed at other time points. In conclusion, the potential therapeutic efficacy of plant-based proteins, hrACE2 and hrACE2-Fd, against COVID-19 was confirmed in a SARS-CoV-2-inoculated Golden Syrian hamster model. Further preclinical studies on primates and humans are necessary to obtain additional evidence and determine the effectiveness of these therapies.

Facilitation of Dye-Based Quantitative Real-Time Polymerase Chain Reaction with Poly(ethylene glycol)-Engrafted Graphene Oxide

Quantitative real-time polymerase chain reaction (qPCR) is an important and extensively utilized technique in medical and biotechnological applications. qPCR enables the real-time detection of nucleic acid during amplification, thus surpassing the necessity of post-amplification gel electrophoresis for amplicon detection. Despite being widely employed in molecular diagnostics, qPCR exhibits limitations attributed to nonspecific DNA amplification that compromises the efficiency and fidelity of qPCR. Herein, we demonstrate that poly(ethylene glycol)-engrafted nanosized graphene oxide (PEG-nGO) can significantly improve the efficiency and specificity of qPCR by adsorbing single-stranded DNA (ssDNA) without affecting the fluorescence of double-stranded DNA binding dye during DNA amplification. PEG-nGO adsorbs surplus ssDNA primers in the initial phase of PCR, having lower concentrations of DNA amplicons and thus minimizing the nonspecific annealing of ssDNA and false amplification due to primer dimerization and erroneous priming. As compared to conventional qPCR, the addition of PEG-nGO and the DNA binding dye, EvaGreen, in the qPCR setup (dubbed as PENGO-qPCR) significantly enhances the specificity and sensitivity of DNA amplification by preferential adsorption of ssDNA without inhibiting DNA polymerase activity. The PENGO-qPCR system for detection of influenza viral RNA exhibited a 67-fold higher sensitivity than the conventional qPCR setup. Thus, the performance of a qPCR can be greatly enhanced by adding PEG-nGO as a PCR enhancer as well as EvaGreen as a DNA binding dye to the qPCR mixture, which exhibits a significantly improved sensitivity of the qPCR.

Which Radiographic Parameter Can Aid in Deciding Optimal Allograft Height for Anterior Cervical Discectomy and Fusion?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To identify preoperative radiographic parameters that can guide optimal allograft height selection for anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Allograft height selection for ACDF depends on intraoperative assessment supported by trials; however, there is currently no radiographic reference parameter that could aid in allograft height selection for improved outcomes.

METHODS

A total of 148 patients who underwent ACDF using allografts and were followed up for more than 1 year were retrospectively reviewed. Fusion rates, subsidence, segmental lordosis, and foraminal height were assessed. Segments were divided into 2 groups according to whether the inserted allograft height was within 1 mm from the following 3 reference radiographic parameters: (1) uncinate process height, (2) adjacent disc height, and (3) preoperative disc height +2 mm.

RESULTS

This study included 101 patients with 163 segments. Segments with an allograft-uncinate height difference of ≤1 mm had a significantly higher fusion rate at 1-year follow-up compared with segments with allograft-uncinate height difference of >1 mm [85/107 (79.4%) vs. 35/56 (62.5%); P =0.025]. Subsidence, segmental lordosis, and foraminal height did not significantly differ between the groups when segments were divided according to uncinate height. Multivariate logistic regression analysis demonstrated that allograft-uncinate height difference of ≤1 mm and allograft failure were factors associated with fusion.

CONCLUSIONS

The uncinate process height can guide optimal allograft height selection for ACDF. Using an allograft with an allograft-uncinate height difference of ≤1 mm resulted in a higher fusion rate. Therefore, the uncinate process height should be checked preoperatively and used in conjunction with intraoperative assessment when selecting allograft height.

Diagnostic Sensitivity of Saliva and Other Respiratory Tract Samples of SARS-CoV-2 Variants in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to emerge during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Contrasting studies on the omicron variant have demonstrated higher viral loads in different clinical specimens, which is consistent with its high transmissibility. We investigated the viral load in clinical specimens that were infected with the SARS-CoV-2 wild-type, delta, and omicron variants, and we analyzed the diagnostic accuracy of upper and lower respiratory specimens for these variants. We performed nested reverse transcription (RT)-polymerase chain reaction (PCR), targeting the spike gene and sequencing for variant classification. RT-PCR was performed using upper and lower respiratory specimens, including saliva from 78 COVID-19 patients (wild-type, delta, and omicron variants). A comparison of the sensitivity and specificity, using the area under the receiver operating characteristic curve (AUC) values from the N gene, showed that the omicron variant saliva samples had a higher sensitivity (AUC = 1.000) than did the delta (AUC = 0.875) and the wild-type (AUC = 0.878) variant samples. The sensitivity of the omicron saliva samples was greater than that of the wild-type nasopharynx and sputum samples (P < 0.001). The viral loads of the saliva samples containing the wild-type, delta, and omicron variants were 8.18 × 105, 2.77 × 106, and 5.69 × 105, respectively, which did not differ significantly (P = 0.610). Statistically significant differences were not observed in the saliva viral loads between vaccinated and nonvaccinated patients who were infected with the omicron variant (P = 0.120). In conclusion, omicron saliva samples had higher sensitivity than did wild-type and delta samples, and the viral load did not significantly differ between vaccinated and nonvaccinated patients. Further research is necessary to elucidate the mechanisms underlying the sensitivity differences. IMPORTANCE Owing to the vast heterogeneity of the studies focused on the correlation between the SARS-CoV-2 omicron variant and COVID-19, accurate comparisons of the specificity and sensitivity of samples and associated outcomes are still inconclusive. Moreover, limited information is available on the leading causes of infection and the factors that are associated with the conditions that underlie the spread of infection. Although several studies have contributed important knowledge regarding infectious specimens, the impact of saliva samples remains unknown. This study showed that the sensitivity of the omicron variant saliva samples was higher than that of the wild-type nasopharyngeal and sputum samples. Moreover, neither vaccinated nor nonvaccinated patients who were infected with the omicron variant showed any significant differences in SARS-CoV-2 viral loads. Hence, this study is an important step toward understanding how saliva sample results are correlated with other specimen results, regardless of the vaccination status of patients who are infected with the SARS-CoV-2 omicron variant.

Seroprevalence of severe fever with thrombocytopenia syndrome using specimens from the Korea National Health & Nutrition Examination Survey

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an acute febrile disease caused by bites from ticks infected with the SFTS virus. In Korea, SFTS patients are observed nationwide, including Jeju Island, but there are currently no data regarding the national prevalence of SFTS, including that of residents of 16 cities and provinces. This study aimed to investigate the seroprevalence of SFTS in Korea.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 1500 participants were selected through random sampling from the 2014-2015 Korea National Health and Nutrition Examination Survey (KNHANES). An indirect immunofluorescence antibody assay (IFA) was performed to assess immunoglobulin (Ig) G and IgM antibody titers against SFTS virus.

RESULTS

Of the 1500 participants, 55 (3.7%) tested positive for IgG and 1 (0.1%) tested positive for IgM, with antibody titer of ≥ 1:32. Approximately 3.9% and 2.5% of participants in urban and rural areas, respectively, had a positive titer of ≥ 1:32. There was a significant correlation between SFTS incidence per 100,000 population and seroprevalence using an IgG titer ≥ 1:64 as the cut-off value.

CONCLUSION

This is the first study to investigate national SFTS seroprevalence in all 16 cities and provinces representing Korea. Our study will also provide useful guidelines for the development of preventive measures against SFTS.

The Seroprevalence of Severe Fever with Thrombocytopenia Syndrome: An Epidemiological Study of Korean Veterinary Hospital Workers

Severe fever with thrombocytopenia syndrome (SFTS) is a zoonotic tick-borne infectious disease caused by the SFTS virus (SFTSV). Few studies have assessed SFTS seroprevalence among veterinary hospital staff and their awareness of SFTS. From January to May 2021, serum samples from 103 veterinary hospital staff were tested for SFTS using an enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay, and a 50% plaque reduction neutralization antibody test, which yielded positive results in four (3.9%), three (2.9%), and two (1.9%) participants, respectively. A questionnaire was used for an epidemiological investigation. ELISA positivity was higher among those who lacked awareness of possible animal-to-human SFTS transmission (p = 0.029). SFTS awareness was significantly lower among veterinary hospital staff than among the veterinarians (p < 0.001). Providing staff with training concerning standard precautions and the use of appropriate personal protective equipment is important.

Axion Dark Matter Search around 4.55 μeV with Dine-Fischler-Srednicki-Zhitnitskii Sensitivity

We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the CAPP-12TB haloscope, assuming axions contribute 100% of the local dark matter density. The search excluded the axion-photon coupling g_{aγγ} down to about 6.2×10^{-16}  GeV^{-1} over the axion mass range between 4.51 and 4.59  μeV at a 90% confidence level. The achieved experimental sensitivity can also exclude Kim-Shifman-Vainshtein-Zakharov axion dark matter that makes up just 13% of the local dark matter density. The CAPP-12TB haloscope will continue the search over a wide range of axion masses.

Augmented humoral and cellular immunity against severe acute respiratory syndrome coronavirus 2 after breakthrough infection in kidney transplant recipients who received 3 doses of coronavirus disease 2019 vaccine

Diminished immune response to coronavirus disease 2019 (COVID-19) vaccines and breakthrough infection (BI) is a major concern for solid organ transplant recipients. Humoral and cellular immune responses of kidney transplant (KT) recipients after a third COVID-19 vaccination were investigated compared to matched health care workers. Anti-severe acute respiratory syndrome coronavirus 2 spike protein antibody and severe acute respiratory syndrome coronavirus 2 specific interferon-gamma releasing assay (IGRA) were assessed. A total of 38 KT recipients, including 20 BI and 18 noninfection, were evaluated. In the KT BI group, antibody titers were significantly increased (median 5 to 724, binding antibody units/mL (P = 0.002) after the third vaccination, but IGRA responses were negligible. After BI, antibody titers increased (median 11 355 binding antibody unit/mL; P < 0.001) and there was a significant increase of IGRA responses to spike proteins (Spike₁-Nil, median 0.05 to 0.41 IU/mL; P = 0.009). Antibody titers and IGRA responses were significantly higher in the BI than in the noninfection group after 6 months. Immune responses were stronger in the health care worker than in the KT cohort, but the gap became narrower after BI. In conclusion, KT recipients who experienced BI after 3 COVID-19 vaccinations acquired augmented humoral and cellular immune responses.

Colorimetric Systems for the Detection of Bacterial Contamination: Strategy and Applications

Bacterial contamination is a public health concern worldwide causing enormous social and economic losses. For early diagnosis and adequate management to prevent or treat pathogen-related illnesses, extensive effort has been put into the development of pathogenic bacterial detection systems. Colorimetric sensing systems have attracted increasing attention due to their simple and single-site operation, rapid signal readout with the naked eye, ability to operate without external instruments, portability, compact design, and low cost. In this article, recent trends and advances in colorimetric systems for the detection and monitoring of bacterial contamination are reviewed. This article focuses on pathogen detection strategies and technologies based on reaction factors that affect the color change for visual readout. Reactions used in each strategy are introduced by dividing them into the following five categories: external pH change-induced pH indicator reactions, intracellular enzyme-catalyzed chromogenic reactions, enzyme-like nanoparticle (NP)-catalyzed substrate reactions, NP aggregation-based reactions, and NP accumulation-based reactions. Some recently developed colorimetric systems are introduced, and their challenges and strategies to improve the sensing performance are discussed.

Emerging hantavirus infection in wild rodents captured in suburbs of Gwangju Metropolitan City, South Korea

Background

Hemorrhagic fever with renal syndrome (HFRS) caused by hantaviruses is a frequently reported acute hemorrhagic fever in South Korea. These viruses are transmitted by various rodent species such as Apodemus agrarius.

Methodology/Principal findings

To investigate hantavirus infection and seroprevalence in rodents, wild rodents were captured from two districts in the suburbs of Gwangju Metropolitan City from January 2016 to December 2018. Nested reverse-transcription polymerase chain reaction (RT-PCR) targeting the hantavirus-specific L segment and indirect immunofluorescence antibody (IFA) assay using Hantaan virus antigen slides were performed. A total of 585 wild rodents were captured—512 A. agrarius, 49 Crocidura lasiura, and 24 Myodes regulus. Nested RT-PCR was performed to examine the rate of hantavirus infection in wild rodents, and 1.88% (11/585) of all rodents, 1.17% (6/512) of A. agrarius, 6.12% (3/49) of C. lasiura, and 8.33% (2/24) of M. regulus tested positive. The nucleotide sequence analysis of the eleven PCR-positive products revealed that six PCR products showed over 85% sequence similarity with the Jeju virus, four showed over 99.7% similarity with the Hantaan virus, and one showed over 95.3% homology with the Imjin virus. Moreover, IgG antibodies against the Hantaan virus were detected in 6.15% (36/585) of all rodents, 6.8% (35/512) of A. agrarius, and 4.17% (1/24) of M. regulus. IgG antibodies were not detected in C. lasiura.

Conclusions/Significance

Hantaviruses were detected in all three wild rodent species of A. agrarius, C. lasiura, and M. regulus captured in the suburbs of Gwangju Metropolitan City, South Korea, and it was demonstrated that they were various strains of hantaviruses such as the Hantaan, Jeju, and Imjin viruses.

Hantaviruses (family Hantaviridae, genus Hantavirus) are rodent viruses that can cause two fatal human diseases—hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. These viruses are transmitted by various rodent species such as Apodemus agrarius. In the present study, wild rodents captured in the suburbs of Gwangju Metropolitan City were analyzed by nested reverse-transcription polymerase chain reaction targeting the hantavirus-specific L segment and indirect immunofluorescence antibody assay using Hantaan virus antigen slides. A total of 585 wild rodents were captured and 1.88% (11/585) of all rodents, 1.17% (6/512) of A. agrarius, 6.12% (3/49) of Crocidura lasiura, and 8.33% (2/24) of Myodes regulus were PCR-positive. Of the eleven PCR-positive wild rodents, six PCR products showed over 85% sequence similarity with the Jeju virus, four showed over 99.7% similarity with the Hantaan virus, and one showed over 95.3% homology with the Imjin virus. Moreover, IgG antibodies against the Hantaan virus were detected in 6.15% (36/585) of all rodents, 6.8% (35/512) of A. agrarius, and 4.17% (1/24) of M. regulus. IgG antibodies were not detected in C. lasiura. When we examined the detection rate of hantavirus genes in different seasons, hantaviruses were most commonly detected in fall (seven cases [5.69%]) and winter (four cases [2.76%]). No hantaviruses were detected in spring or summer. However, the seasonal prevalence of IgG antibodies was higher in spring and summer (12 [7.32%] and 11 [7.10%] cases, respectively) than in fall and winter (seven [5.69%] and six [4.14%] cases, respectively). This study was performed on a monthly basis throughout a three-year period, and thus, it provides reliable data that may provide insight into preventive measures against HFRS. Our results suggest that various types of hantaviruses, including Hantaan, Jeju, and Imjin viruses, are distributed throughout Gwangju Metropolitan City, South Korea. Data regarding the rate of Hantaan virus infection in rodents in Gwangju and knowledge of the hantavirus seroprevalence, species, and genotypes circulating in these domestic rodent species will provide useful information for developing vaccines and diagnostic testing using sequence data. These will help increase preparedness for the emergence of new species.

Effective Drugs Against Severe Fever With Thrombocytopenia Syndrome Virus in an in vitro Model

Background

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by the SFTS virus (SFTSV). This syndrome is endemic in China, South Korea, and Japan, with a fatality rate of approximately 20–30%. Although the World Health Organization has listed SFTS as a disease that requires urgent steps for the development of its treatment, no treatments are available.

Methods

We analyzed the antiviral activity of 41 drugs against the SFTSV to explore potential therapeutic candidates using real-time reverse transcription-polymerase chain reaction and plaque assay in vitro.

Results

Peramivir, nitazoxanide, and favipiravir were found to have inhibitory effects on the SFTSV at concentrations below the maximum plasma concentration (Cmax). The concentrations that inhibited the SFTSV by 50% were as follows: peramivir, half maximal effective concentration (EC₅₀) 12.9 μg/mL; nitazoxanide, EC₅₀ 0.57 μg/mL; and favipiravir, EC₅₀ 4.14 μg/mL.

Conclusion

The effects of peramivir and nitazoxanide on the SFTSV were identified for the first time in this study. Future studies need to include animal models of SFTSV infection, clinical trials including dose-ranging trials, and evaluation of combination therapy with other potential antivirals.

Hemorrhagic Fever with Renal Syndrome: Literature Review, Epidemiology, Clinical Picture and Pathogenesis

Hantaviruses can cause two types of infections in humans: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome. The old world hantaviruses, primarily Hantaan virus (HTNV), responsible for causing HFRS occurs endemically in Asia and Europe. Apodernus agraricus, a striped field mouse, is being considered as main host reservoir for HTNV. Infection in humans is typically accidental and occurs when virus-containing rodent excretions such as urine, feces, or saliva are aerosolized. The major clinical manifestations includes increased vascular permeability causing vascular leakage, acute kidney injury and coagulation abnormalities. The case fatality rate of HFRS varies around 5.0 - 10.0% depending on the causative viral agent. The direct effects of viral infection on endothelial cells, as well as the immunological response to the viral infection, have been suggested to play a key role in the pathogenesis of HFRS. This article summarizes the current knowledge of HFRS epidemiology in Korea and around the globe, etiology, host transmission, clinical presentation, pathogenesis, diagnostic techniques, treatment, and prevention.

Abstract P3-10-02: Enhanced miR-579-3p by anti-estrogen treatment may affect capecitabine response in hormone receptor positive metastatic breast cancer

Purpose Capecitabine is one of a treatment option in anthracycline and taxane pre-treated metastatic breast cancer (MBC) patients. We have performed miRNA microarray of durable and poor responders to capcitabine, and compared with cell line miRNA expression profile (MCF-7, tamoxifen-resistant MCF-7 [MCF-TAM] cell line treated with 5-FU. Methods Between Jan 2006 to Jan 2021, 66 patients treated with capecitabine after anthracycline and taxane failure were enrolled. Twenty-three archival tumor tissues (11 durables and 12 poor responders, each) were collected and went through nCounter miRNA expression assay. MCF-7, tamoxifen resistant MCF-7 (MCF-TAM) cell line was treated with tamoxifen or 5-FU for proliferation assay and also went through nCounter miRNA expression assay. Results HR positive patients who received anti-estrogen treatment before capecitabine showed longer PFS (median 7.7 vs. 4.03 months, P=0.006). MCF-7 treated with tamoxifen and 5-FU showed decreased proliferation compared to 5-FU treated MCF-7. There was significant difference of miR-579-3p expression between durable and poor responders (log2FC -3.02, P=0.004). Tamoxifen-treated MCF-7 cell line showed upregulation of miR-579-3p compared to MCF-7. Tamoxifen + 5-FU treated MCF-7 cell line showed decreased expression of miR-579-3p compared to 5-FU treated MCF-7 cell line. MCF-7 cell line was treated with 5-FU and miR-579-3p. Compared to 5-FU only treated cell line, 5-FU + miR-579-3p treated cell line showed trends for decreased cell proliferation, suggesting that miR-579-3p may have chemo-sensitizing role during systemic chemotherapy. Based on miRNA database, authors hypothesized that MDM2 may be target protein of miR-579-3p and planning to perform further analysis. Conclusions Anti-estrogen treatment before capecitabine administration was associated to better survival in HR positive MBC. Anti-estrogen potentiated the effect of 5-FU in MCF-7. MiR-579-3p was upregulated in durable responders and tamoxifen treated MCF-7 cell line. Further study is planned to analyze the role of miR-579-3p and its potential target, MDM2 in breast cancer.

Citation Format: Jieun Lee, Seung Yeon Joe, Ji-Sun Lee, Dong-Min Kim, Ahwon Lee. Enhanced miR-579-3p by anti-estrogen treatment may affect capecitabine response in hormone receptor positive metastatic breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-10-02.

Case Report: Fulminant Myocarditis Successfully Treated With Extracorporeal Membrane Oxygenation in Ikeda Strain Orientia tsutsugamushi Infection

Scrub typhus is an acute zoonotic febrile illness caused by Orientia tsutsugamushi having a specific geographic endemic area. This infection could be complicated with multi-organ involvement including myocarditis with variable severity. Here, we report a rare case of scrub typhus with biopsy-proven acute fulminant myocarditis which progressed very rapidly to cardiac arrest and was treated successfully with extracorporeal cardiopulmonary resuscitation. Clinicians should be alert to possible rapid progression of scrub typhus myocarditis to fulminant form and be prepared for close monitoring and temporary mechanical support if indicated.

Case Report: The First Borrelia yangtzensis Infection in a Human in Korea

Borrelia yangtzensis has been identified in rodents and ticks in China and Japan. A 57-year-old woman with bite mark was diagnosed with B. yangtzensis infection via molecular and serological testing. Here, we report the first case of human infection caused by B. yangtzensis in Korea.

Eosinophil-mediated lung inflammation associated with elevated natural killer T cell response in COVID-19 patients

BACKGROUND/AIMS

Coronavirus disease 2019 (COVID-19) is associated with acute respiratory syndrome. The mechanisms underlying the different degrees of pneumonia severity in patients with COVID-19 remain elusive. This study provides evidence that COVID-19 is associated with eosinophil-mediated inflammation.

METHODS

We performed a retrospective case series of three patients with laboratory and radiologically confirmed COVID-19 pneumonia admitted to Chosun University Hospital. Demographic and clinical data on inflammatory cell lung infiltration and cytokine levels in patients with COVID-19 were collected.

RESULTS

Cytological analysis of sputum, tracheal aspirates, and bronchoalveolar lavage fluid (BALF) samples from all three patients revealed massive infiltration of polymorphonuclear cells (PMNs), such as eosinophils and neutrophils. All sputum and BALF specimens contained high levels of eosinophil cationic proteins. The infiltration of PMNs into the lungs, together with elevated levels of natural killer T (NKT) cells in BALF and peripheral blood samples from patients with severe pneumonia in the acute phase was confirmed by flow cytometry.

CONCLUSION

These results suggest that the lungs of COVID-19 patients can exhibit eosinophil-mediated inflammation, together with an elevated NKT cell response, which is associated with COVID-19 pneumonia.

Dendropanoxide, a Triterpenoid from Dendropanax morbifera, Ameliorates Hepatic Fibrosis by Inhibiting Activation of Hepatic Stellate Cells through Autophagy Inhibition

Hepatic fibrosis results from chronic liver damage and is characterized by excessive accumulation of extracellular matrix (ECM). In this study, we showed that dendropanoxide (DPX), isolated from Dendropanax morbifera, had anti-fibrotic effects on hepatic fibrosis by inhibiting hepatic stellate cell (HSC) activation. DPX suppressed mRNA and protein expression of α-SMA, fibronectin, and collagen in activated HSCs. Moreover, DPX (40 mg/kg) treatment significantly lowered levels of liver injury markers (aspartate aminotransferase and alanine transaminase), expression of fibrotic markers, and deposition of ECM in a carbon tetrachloride-induced mouse model. Anti-fibrotic effects of DPX were comparable to those of silymarin in a hepatic fibrosis mouse model. As a possible mechanism of anti-fibrotic effects, we showed that DPX inhibited autophagosome formation (LC3B-II) and degradation of p62, which have important roles in HSC activation. These findings suggest that DPX inhibits HSC activation by inhibiting autophagy and can be utilized in hepatic fibrosis therapy.

Usefulness of ELISA Using Total Antibody against Plant-Expressed Recombinant Nucleocapsid Protein of SARS-CoV-2

Here, we aimed to investigate the diagnostic value of a serological assay using the nucleocapsid protein developed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection and evaluated its performance using three commercial enzyme-linked immunosorbent assays (ELISAs), namely, Standard E 2019 novel coronavirus disease (COVID-19) total antibody (Ab) ELISA (SD Biosensor), and EDI novel coronavirus COVID-19 IgG and IgM ELISA. A recombinant nucleocapsid protein (rNP) was expressed from plants and Escherichia coli for the detection of serum total Ab. We prospectively collected 141 serum samples from 32 patients with reverse transcription-PCR (RT-PCR)-confirmed COVID-19 and determined the sensitivity and dynamics of their total Ab response. Specificity was evaluated using 158 prepandemic samples. To validate the assays, we evaluated the performance using two different cutoff values. The sensitivity and specificity for each assay were as follows: 92.91% and 94.30% (plant-rNP), 83.69% and 98.73% (SD Biosensor), 75.89% and 98.10% (E. coli-rNP), 76.47% and 100% (EDI-IgG), and 80.39% and 80% (EDI-IgM). The plant-based rNP showed the highest sensitivity and area under the receiver operating characteristic (ROC) curve (0.980) among all the assays (P < 0.05). The seroconversion rate for total Ab increased sequentially with disease progression, with a sensitivity of 100% after 10 to 12 days of post-symptom onset (PSO) for both rNP-plant-based and SD Biosensor ELISAs. After 2 weeks of PSO, the seroconversion rates were >80% and 100% for EDI-IgM and EDI-IgG ELISA, respectively. Seroconversion occurred earlier with rNP plant-based ELISA (5 days PSO) compared with E. coli-based (7 days PSO) and SD Biosensor (8 days PSO) ELISA. We determined that rNP produced in plants enables the robust detection of SARS-CoV-2 total Abs. The assay can be used for serosurvey and complementary diagnosis of COVID-19. IMPORTANCE At present, the principal diagnostic methods for COVID-19 comprise the identification of viral nucleic acid by genetic approaches, including PCR-based techniques or next-generation sequencing. However, there is an urgent need for validated serological assays which are crucial for the understanding of immune responses against SARS-CoV-2. In this study, a highly sensitive and specific serological antibody assay was developed for the detection of SARS-CoV-2 with an overall accuracy of 93.56% using a recombinant nucleoprotein expressed from plants.

Viable Severe Acute Respiratory Syndrome Coronavirus 2 Isolates Exhibit Higher Correlation With Rapid Antigen Assays Than Subgenomic RNA or Genomic RNA

Background: Rapid identification and effective isolation are crucial for curbing the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To meet this requirement, antigen-detection rapid diagnostic tests (Ag-RDTs) are essential.

Methods: Between February 2020 and August 2020 we performed a cohort study of patients with confirmed COVID-19. The clinical performance of Ag rapid fluorescence immunoassay (FIA) and Ag Gold was evaluated and compared in parallel with genomic and subgenomic real-time reverse transcription-polymerase chain reaction (rRT-PCR) and cell culture-based assays.

Results: In total, 150 samples were tested. Of these, 63 serial samples were obtained from 11 patients with SARS-CoV-2 and 87 from negative controls. Serial respiratory samples were obtained 2 days prior to symptom onset (-2) up to 25 days post-symptom onset. Overall, for rRT-PCR-positive samples (n = 51), the detection sensitivity of Ag rapid FIA and Ag Gold was 74.5% and 53.49%, respectively, with a specificity of 100%; however, for samples with low cycle threshold (Ct) values, Ag rapid FIA and Ag Gold exhibited a sensitivity of 82.61% (Ct ≤ 30, 5.6 log₁₀RNA copies/mL) and 80% (Ct ≤ 25, 6.9 log₁₀RNA copies/mL), respectively. Despite low analytical sensitivity, both Ag-RDTs detected 100% infection in cell culture-positive samples (n = 15) and were highly effective in distinguishing viable samples from those with subgenomic RNA (66.66%). For both Ag-RDTs, all samples that yielded discordant results (rRT-PCR + ve/Ag-RDT -ve) were also negative by culture.

Conclusion: The data suggest that Ag-RDTs reliably detect viable SARS-CoV-2; thus, they may serve as an important tool for rapid detection of potentially infectious individuals.

Human granulocytic anaplasmosis combined with rhabdomyolysis: a case report

BACKGROUND

Human granulocytic anaplasmosis (HGA) is a systemic inflammatory response caused by the rickettsial bacterium Anaplasma phagocytophilum. Rhabdomyolysis and acute kidney injury (AKI) are rare complications of HGA. Here, we report a case of HGA concurrent with rhabdomyolysis and AKI in an elderly patient.

CASE PRESENTATION

An 84-year old woman with a medical history of hypertension was hospitalised after two days of fever, dizziness, whole body pain, and general weakness. Laboratory investigations showed severe thrombocytopenia, leukopenia, impaired renal function, and elevated cardiac enzyme and myoglobin levels. On the day after admission, peripheral blood smear revealed morula inclusions in neutrophils, a suggestive finding of HGA. Real-time polymerase chain reaction (PCR) results indicated the presence of A. phagocytophilum. Antibiotics were de-escalated to doxycycline monotherapy. After 10 days of antibiotic treatment, laboratory tests showed complete recovery from HGA complicated with rhabdomyolysis and AKI.

CONCLUSIONS

HGA can lead to serious complications in patients with associated risk factors. Therefore, in patients with HGA accompanied by rhabdomyolysis, management with antibiotics and hydration should be initiated immediately, and not delayed until diagnostic confirmation.

Potential-Dependent Passivation of Zinc Metal in a Sulfate-Based Aqueous Electrolyte

Owing to its abundance, high theoretical capacity, and low electrode potential, zinc is one of the most important metallic anodes for primary and secondary batteries such as alkaline and zinc-air batteries. In the operation of zinc-based batteries, passivation of the anode surface plays an essential role because the electrode potential of zinc is slightly below that of the hydrogen evolution reaction. Therefore, it is important to scrutinize the nature of the passivation film to achieve anticorrosion inside batteries. Herein, the potential-dependent formation and removal of the passivation film during the deposition and dissolution of zinc metal in aqueous electrolytes are detected via electrochemical quartz crystal microbalance analysis. Film formation was not noticeable in hydroxide-based electrolytes; however, sulfate-based electrolytes induced potential-dependent formation and removal of the passivation film, enabling a superior coulombic efficiency of 99.37% and significantly reducing the rate of corrosion of the zinc-metal anodes. These observations provide insights into the development of advanced electrolytes for safe and stable energy-storage devices based on zinc-metal anodes.

Geographical clustering of Hantavirus isolates from Apodemus agrarius identified in the Republic of Korea indicate the emergence of a new Hantavirus genotype

AIM AND METHODOLOGY

Several studies on hantavirus evolution have shown that genetic reassortment plays an important role in the evolution and epidemiology of this disease. To understand the genetic epidemiology of human hantaviruses, samples from rodent reservoirs were subjected to reverse-transcription nested polymerase chain reaction (RT-N-PCR) targeting the L- and S-segments of the hantavirus genome.

RESULTS

Positive isolates from Gwangju, Boseong-gun (Jeollanam-do Province), and Jeju Island were confirmed as Hantaan virus using DNA sequencing. Phylogenetic analysis showed that all isolates grouped together as Hantaan virus but with each region forming a distinct cluster. In addition, these three clusters were distinct from other Hantaan isolates reported in previous studies from Korea and its neighboring countries China and Russia.

CONCLUSION

This suggests Hantaan viruses exhibit a considerable degree of geographical clustering, and there may be a novel Hantaan genotype in southwestern ROK. This study helps expand our knowledge regarding the emergence of new hantavirus strains and their degree of geographical variation.

IMPORTANCE

Hantaan virus, a pathogenic prototype hantavirus carried by Apodemus agrarius, is found throughout China, Russia, and Korea. Here, we examined the genetic diversity of hantaviruses to expand our knowledge regarding the emergence of new hantavirus strains and their degree of geographical variation. We found that hantaan viruses show a considerable degree of geographical clustering, which may allude to the development of a new genotype variant in the southwestern region of the ROK.

Viral Kinetics of Severe Acute Respiratory Syndrome Coronavirus 2 in Patients with Coronavirus Disease 2019

To determine the relationship between viral kinetics and severity of disease in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we investigated the viral kinetics and compared the viral loads of patients with coronavirus disease 2019 (COVID-19; the disease caused by SARS-CoV-2), stratified by symptoms and severity. We determined the viral kinetics of 100 patients diagnosed with COVID-19 at Chosun University Hospital between February 2020 and May 2021 and analyzed the differences between asymptomatic, symptomatic, and nonsurvivor patients and between patients who died and those who survived. Clinical samples, comprising respiratory specimens (sputum samples and nasopharynx and oropharynx swab samples), were obtained at different time points of hospitalization, at 1, 3 to 5, 7, 10, 14, and 30 days. SARS-CoV-2 was detected using real-time reverse transcription-PCR (RT-PCR). All three groups, asymptomatic, symptomatic, and deceased patients, had higher numbers of viral copies at symptom onset, and the asymptomatic group had lower numbers of viral copies than the symptomatic or nonsurvivor group. Viral RNA release was detected until 30 days after symptom onset. The virus cleared up earlier in asymptomatic patients than in symptomatic and nonsurvivor patients, and it cleared up earlier in mildly affected patients than in severely affected patients. The cycle threshold values tended to be significantly lower in the group receiving steroids than in the nonsteroid group, even in the low-risk group with a pneumonia severity index of less than 90. The viral loads in patients with COVID-19 were significantly different according to disease severity and steroid use. IMPORTANCE In our study, we analyzed the viral kinetics of COVID-19 patients. Our study reveals differences in viral shedding according to the severity of disease in COVID-19 patients. Viral shedding had a longer duration in severely affected patients, and the cyclic threshold values were lower in the group receiving steroids. This study is expected to be helpful in analyzing the trend of the disease course according to steroid use and severity of SARS-CoV-2 disease.

Potential efficacy of existing drug molecules against severe fever with thrombocytopenia syndrome virus: an in silico study

Severe fever with thrombocytopenia syndrome (SFTS) is a zoonotic disease caused by the SFTS virus (SFTSV). SFTS can be considered a life-threatening notifiable infectious disease. The unavailability of specific therapeutics encourages the investigation of potential efficacy of existing drugs against this infection. Drug repurposing was done by performing  virtual screening of already established drug molecules followed by 100 ns molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area-based binding-energy calculation by targeting the SFTS L protein. On the basis of binding energy and protein-ligand interactions, top 10 promising hits were identified, showing stable binding with SFTS L protein. Further 100 ns atomistic MD simulation refined the hits from top 10 to top 4 with docking-based binding energy lesser than -8.0 kcal/mol toward the SFTS L protein and engaged in π-π interactions with pivotal amino acid residues. Various parameters and binding affinity of top 4 ligands towards L protein was computed. Ligand zaltoprofen exhibited best binding energy -220.095 kJ/mol. The present work is the first in silico study to assess bromfenac, cinchophen, elliptinium, and zaltoprofen; four promising hits against SFTS. Nonetheless, further proper biological evaluation is necessary to determine their efficacy against SFTS.

Enhanced eosinophil-mediated inflammation associated with antibody and complement-dependent pneumonic insults in critical COVID-19

Despite the worldwide effect of the coronavirus disease 2019 (COVID-19) pandemic, the underlying mechanisms of fatal viral pneumonia remain elusive. Here, we show that critical COVID-19 is associated with enhanced eosinophil-mediated inflammation when compared to non-critical cases. In addition, we confirm increased T helper (Th)2-biased adaptive immune responses, accompanying overt complement activation, in the critical group. Moreover, enhanced antibody responses and complement activation are associated with disease pathogenesis as evidenced by formation of immune complexes and membrane attack complexes in airways and vasculature of lung biopsies from six fatal cases, as well as by enhanced hallmark gene set signatures of Fcγ receptor (FcγR) signaling and complement activation in myeloid cells of respiratory specimens from critical COVID-19 patients. These results suggest that SARS-CoV-2 infection may drive specific innate immune responses, including eosinophil-mediated inflammation, and subsequent pulmonary pathogenesis via enhanced Th2-biased immune responses, which might be crucial drivers of critical disease in COVID-19 patients.

Recent Advances in Micro/Nanomaterial-Based Aptamer Selection Strategies

Aptamers are artificial nucleic acid ligands that have been employed in various fundamental studies and applications, such as biological analyses, disease diagnostics, targeted therapeutics, and environmental pollutant detection. This review focuses on the recent advances in aptamer discovery strategies that have been used to detect various chemicals and biomolecules. Recent examples of the strategies discussed here are based on the classification of these micro/nanomaterial-mediated systematic evolution of ligands by exponential enrichment (SELEX) platforms into three categories: bead-mediated, carbon-based nanomaterial-mediated, and other nanoparticle-mediated strategies. In addition to describing the advantages and limitations of the aforementioned strategies, this review discusses potential strategies to develop high-performance aptamers.

Comparison of RT-PCR, RT-nested PCRs, and real-time PCR for diagnosis of severe fever with thrombocytopenia syndrome: a prospective study

We designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients’ blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset.

Utility of Nested Reverse-Transcriptase Polymerase Chain Reaction of Clinical Specimens for Early Diagnosis of Hemorrhagic Fever with Renal Syndrome

Hemorrhagic fever with renal syndrome (HFRS) is confirmed by the isolation of hantavirus from serum, detection of virus-specific IgM, or a four-fold change in IgG titers during the acute and convalescent periods measured using an immunofluorescence assay (IFA). However, these tests are inefficient for early diagnosis. Therefore, this study investigated the usefulness of reverse-transcriptase nested polymerase chain reaction (RT-nPCR) for early diagnosis of HFRS using clinical samples such as urine and serum. Electronic medical records of eight patients with confirmed HFRS using IFA and RT-nPCR between May 2016 and May 2020 at Chosun University Hospital were reviewed. The virus was detected in all patients using RT-nPCR targeting the large (L) segment of hantavirus during the early phase in urine and serum. Importantly, the virus was identified in urine at a time when it was not identified in serum. Additionally, the virus was detected in urine and serum for up to 1 month after initial presentation with illness, but not in saliva, using RT-nPCR. We report eight HFRS cases diagnosed using urine and serum, but not using saliva, with RT-nPCR targeting the L-segment. Hantavirus RNA detection by RT-nPCR in urine and serum may aid the rapid diagnosis of HFRS during the early phase of the disease. In particular, HFRS should not be ruled out based on negative RT-PCR results in serum, and RT-PCR should be performed using urine as well as serum during the early phase of symptoms.

Clinical Usefulness of Nested Reverse-Transcription Polymerase Chain Reaction for the Diagnosis of Severe Fever with Thrombocytopenia Syndrome

Severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV) is an emerging tick-borne infectious disease. Few studies have assessed the clinical usefulness of nested reverse-transcription polymerase chain reaction (RT-PCR) for diagnosing SFTS. We performed conventional RT-PCR targeting the M segment, nested RT-PCR targeting M and S segments, and real-time RT-PCR targeting the S segment of SFTSV for four patients with suspected SFTS. Although conventional RT-PCR results for the first two patients were negative at admission, nested RT-PCR using the S or M targets was positive for the same samples. Likewise, in the other two patients, initial samples were confirmed positive in all three tests, but follow-up testing demonstrated negative conventional RT-PCR and positive nested RT-PCR results. Thus, delayed testing using conventional RT-PCR or real-time RT-PCR in symptomatic patients with SFTS may result in missed diagnoses, and compared with these methods, nested RT-PCR may increase the window for obtaining positive SFTSV PCR results. Meanwhile, the indirect immunofluorescence assay showed seroconversion to SFTSV antibodies in all four patients. Nested RT-PCR for SFTSV M and S segments could help diagnose SFTS in patients testing negative by conventional RT-PCR.

Three-Dimensional Porous Frameworks for Li Metal Batteries: Superconformal versus Conformal Li Growth

Li metal batteries have been considered a promising alternative to Li-ion batteries because of the high theoretical capacity of the Li metal. There have been remarkable improvements in the electrochemical performance of Li metal electrodes, although the current Li metal technology is not sufficiently practical in terms of cycle performance, safety, and volume change during cycling. Herein, the role of pore size distribution in the Li metal plating behavior of porous frameworks is clarified to attain the ideal pore structure of the framework as a Li metal host. The monodisperse pore framework shows the conformal electrodeposition of the Li metal, whereas the pore size gradient framework exhibits the superconformal plating of the Li metal. The conformal and superconformal electrodepositions of the Li metal are elucidated in terms of variations along the pore depth direction in the charge-transfer resistance on the pore walls and the ionic resistance of electrolytes confined in pores. The pore size gradient framework also shows excellent electrochemical performance, such as stable capacity retention over 760 cycles with 0.5 mAh cm^-2 at 2 mA cm^-2. These findings provide fundamental insights into strategies to improve the electrochemical performance of porous frameworks for Li metal batteries.

Molecular detection and identification of Culex flavivirus in mosquito species from Jeju, Republic of Korea

Background

Mosquito-borne flaviviruses are prime pathogens and have been a major hazard to humans and animals. They comprise several arthropod-borne viruses, including dengue virus, yellow fever virus, Japanese encephalitis virus, and West Nile virus. Culex flavivirus (CxFV) is a member of the insect-specific flavivirus (ISF) group belonging to the genus Flavivirus, which is widely distributed in a variety of mosquito populations.

Methods

Viral nucleic acid was extracted from adult mosquito pools and subjected to reverse transcriptase nested polymerase chain reaction (PCR) using target-specific primers for detecting CxFV nonstructural protein 5 (NS5). The PCR-positive samples were then sequenced, and a phylogenetic tree was constructed, including reference sequences obtained from GenBank.

Results

21 pools, belonging to Culex pipiens pallens (Cx. p. pallens) were found to be positive for the CxFV RNA sequence, with a minimum infection rate of 14.5/1000 mosquitoes. The phylogenetic analysis of the NS5 protein sequences indicated that the detected sequences were closely related to strains identified in China, with 95–98% sequence similarities.

Conclusion

Our findings highlight the presence of CxFV in Cx. p. pallens mosquito species in Jeju province, Republic of Korea. This is the first study reporting the prevalence of CxFV in Culex Pipiens (Cx. pipiens) host in the Jeju province, which can create possible interaction with other flaviviruses causing human and animal diseases. Although, mosquito-borne disease causing viruses were not identified properly, more detailed surveillance and investigation of both the host and viruses are essential to understand the prevalence, evolutionary relationship and genetic characteristic with other species.

Acute Appendicitis Associated with Hantaan Virus Infection

Hantaviruses are Bunyaviridae viruses that cause hemorrhagic fever with renal syndrome. Appendicitis caused by Hantaan virus has not been reported previously. An 81-year-old man who underwent laparoscopic appendectomy for suspected appendicitis based on abdominal pain, fever, hypotension, and computed tomography findings. Based on a suspicion of hemorrhagic fever with renal syndrome, the patient's plasma was simultaneously analyzed using an indirect immunofluorescent antibody assay and nested reverse transcription-polymerase chain reaction (RT-PCR). The appendix tissue was also analyzed using nested RT-PCR and immunohistochemical (IHC) staining to identify the presence of Hantaan virus. Nested RT-PCR detected the presence of Hantaan virus, and indirect immunofluorescent antibody assay results revealed the presence of elevated antibody levels. Furthermore, IHC staining of the appendix tissue confirmed Hantaan virus antigens in the peripheral nerve bundle. Based on these findings, we confirmed the nerve tropism of the Hantaan virus. Hantaan virus in plasma and appendix tissue samples was confirmed using PCR and phylogenetic tree analysis. Moreover, we detected hypertrophy of the submucosa and periappendiceal adipose tissue nerve bundle along with Hantaan virus antigens in peripheral nerve bundles using IHC staining. Hence, we report that Hantaan virus infection may be accompanied by appendicitis.

Acute Appendicitis Associated with Hantaan Virus Infection

Hantaviruses are Bunyaviridae viruses that cause hemorrhagic fever with renal syndrome. Appendicitis caused by Hantaan virus has not been reported previously. An 81-year-old man who underwent laparoscopic appendectomy for suspected appendicitis based on abdominal pain, fever, hypotension, and computed tomography findings. Based on a suspicion of hemorrhagic fever with renal syndrome, the patient's plasma was simultaneously analyzed using an indirect immunofluorescent antibody assay and nested reverse transcription-polymerase chain reaction (RT-PCR). The appendix tissue was also analyzed using nested RT-PCR and immunohistochemical (IHC) staining to identify the presence of Hantaan virus. Nested RT-PCR detected the presence of Hantaan virus, and indirect immunofluorescent antibody assay results revealed the presence of elevated antibody levels. Furthermore, IHC staining of the appendix tissue confirmed Hantaan virus antigens in the peripheral nerve bundle. Based on these findings, we confirmed the nerve tropism of the Hantaan virus. Hantaan virus in plasma and appendix tissue samples was confirmed using PCR and phylogenetic tree analysis. Moreover, we detected hypertrophy of the submucosa and periappendiceal adipose tissue nerve bundle along with Hantaan virus antigens in peripheral nerve bundles using IHC staining. Hence, we report that Hantaan virus infection may be accompanied by appendicitis.

Molecular investigation of tick-borne pathogens in ticks removed from tick-bitten humans in the southwestern region of the Republic of Korea

In this study, we investigated the presence of tick-borne pathogens in ticks removed from tick-bitten humans in the southwestern provinces of the Republic of Korea (ROK). We identified 33 ticks from three tick species, namely Amblyomma testudinarium (60.6%), Haemaphysalis longicornis (27.3%), and Ixodes nipponensis (12.1%) in order of occurrence via morphology and 16S rDNA-targeting polymerase chain reaction (PCR). Tick-borne pathogens were detected in 16 ticks using pathogen-specific PCR. From the results, 12 ticks (36.4%) tested positive for spotted fever group (SFG) Rickettsia: Rickettsia monacensis (1/12), R. tamurae (8/12), and Candidatus Rickettsia jingxinensis (3/12). Three ticks (9.1%) were positive for Anaplasma phagocytophilum. In addition, three ticks (9.1%) tested positive for Babesia gibsoni (1/3) and B. microti (2/3). In conclusion, we identified three tick species; the most common species was A. testudinarium, followed by H. longicornis and I. nipponensis. SFG Rickettsia, A. phagocytophilum, and Babesia spp. were the most frequently detected pathogens in ticks removed from tick-bitten humans. To our knowledge, this is the first report of R. tamurae and Ca. R. jingxinensis detection in Korea. The present results will contribute to the understanding of tick-borne infections in animals and humans in the ROK.