Radiopharmaceuticals for Skeletal Muscle PET Imaging.

The skeletal muscles account for approximately 40% of the body weight and are crucial in movement, nutrient absorption, and energy metabolism. Muscle loss and decline in function cause a decrease in the quality of life of patients and the elderly, leading to complications that require early diagnosis. Positron emission tomography/computed tomography (PET/CT) offers non-invasive, high-resolution visualization of tissues. It has emerged as a promising alternative to invasive diagnostic methods and is attracting attention as a tool for assessing muscle function and imaging muscle diseases. Effective imaging of muscle function and pathology relies on appropriate radiopharmaceuticals that target key aspects of muscle metabolism, such as glucose uptake, adenosine triphosphate (ATP) production, and the oxidation of fat and carbohydrates. In this review, we describe how [18F]fluoro-2-deoxy-D-glucose ([18F]FDG), [18F]fluorocholine ([18F]FCH), [11C]acetate, and [15O]water ([15O]H2O) are suitable radiopharmaceuticals for diagnostic imaging of skeletal muscles.

The HSP90 inhibitor HVH-2930 exhibits potent efficacy against trastuzumab-resistant HER2-positive breast cancer.

Rationale: Resistance to targeted therapies like trastuzumab remains a critical challenge for HER2-positive breast cancer patients. Despite the progress of several N-terminal HSP90 inhibitors in clinical trials, none have achieved approval for clinical use, primarily due to issues such as induction of the heat shock response (HSR), off-target effects, and unfavorable toxicity profiles. We sought to examine the effects of HVH-2930, a novel C-terminal HSP90 inhibitor, in overcoming trastuzumab resistance. Methods: The effect of HVH-2930 on trastuzumab-sensitive and -resistant cell lines in vitro was evaluated in terms of cell viability, expression of HSP90 client proteins, and impact on cancer stem cells. An in vivo model with trastuzumab-resistant JIMT-1 cells was used to examine the efficacy and toxicity of HVH-2930. Results: HVH-2930 was rationally designed to fit into the ATP-binding pocket interface cavity of the hHSP90 homodimer in the C-terminal domain of HSP90, stabilizing its open conformation and hindering ATP binding. HVH-2930 induces apoptosis without inducing the HSR but by specifically suppressing the HER2 signaling pathway. This occurs with the downregulation of HER2/p95HER2 and disruption of HER2 family member heterodimerization. Attenuation of cancer stem cell (CSC)-like properties was associated with the downregulation of stemness factors such as ALDH1, CD44, Nanog and Oct4. Furthermore, HVH-2930 administration inhibited angiogenesis and tumor growth in trastuzumab-resistant xenograft mice. A synergistic effect was observed when combining HVH-2930 and paclitaxel in JIMT-1 xenografts. Conclusion: Our findings highlight the potent efficacy of HVH-2930 in overcoming trastuzumab resistance in HER2-positive breast cancer. Further investigation is warranted to fully establish its therapeutic potential.

Soft tissue myxoma manifesting as a slowly growing subcutaneous mass in the anterior chest wall: A case report.

Soft tissue myxomas are benign mesenchymal neoplasms typically found in the intramuscular components of the proximal extremities. However, soft tissue myxomas in the chest wall are rare. We report the case of a 41-year-old woman with soft tissue myxoma who presented with a slowly growing, palpable lump on her left anterior chest wall that has been present for several years. Mammography revealed an oval, circumscribed, and hyperdense mass in the retromammary fat layer of the upper inner quadrant of the left breast. Ultrasonography revealed an oval, circumscribed, and hypoechoic mass with internal echoes and multiple microcystic spaces. A triangular hyperechoic area adjacent to the pole of the mass and peripheral hyperechoic rim were also detected. The patient underwent surgical excision and was diagnosed with soft tissue myxoma with subcutaneous manifestation.

Mechanical Activation of Graphite for Na-Ion Battery Anodes: Unexpected Reversible Reaction on Solid Electrolyte Interphase via X-Ray Analysis.

Although sodium-ion batteries (SIBs) offer promising low-cost alternatives to lithium-ion batteries (LIBs), several challenges need to be overcome for their widespread adoption. A primary concern is the optimization of carbon anodes. Graphite, vital to the commercial viability of LIBs, has a limited capacity for sodium ions. Numerous alternatives to graphite are explored, particularly focusing on disordered carbons, including hard carbon. However, compared with graphite, most of these materials underperform in LIBs. Furthermore, the reaction mechanism between carbon and sodium ions remains ambiguous owing to the structural diversity of disordered carbon. A straightforward mechanical approach is introduced to enhance the sodium ion storage capacity of graphite, supported by comprehensive analytical techniques. Mechanically activated graphite delivers a notable reversible capacity of 290.5 mAh·g-1 at a current density of 10 mA·g-1. Moreover, it maintains a capacity of 157.7 mAh·g-1 even at a current density of 1 A·g-1, benefiting from the defect-rich structure achieved by mechanical activation. Soft X-ray analysis revealed that this defect-rich carbon employs a sodium-ion storage mechanism distinct from that of hard carbon. This leads to an unexpected reversible reaction on the solid electrolyte surface. These insights pave the way for innovative design approaches for carbon electrodes in SIB anodes.

Evaluating the validity and reliability of the Korean version of Scales for Outcomes in Parkinson's Disease-Cognition.

Objective: The Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA-Cog) was developed to screen for cognition in PD. In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPA-cog. Methods: We recruited 129 PD patients from 31 clinics with movement disorders in South Korea. The original version of the SCOPA-cognition was translated into Korean using the translation-retranslation method. The test-rest method with an intraclass correlation coefficient (ICC) and Cronbach's alpha coefficient were used to assess reliability. The Spearman's Rank correlation analysis with Montreal Cognitive Assessment-Korean version (MOCA-K) and Korean Mini-Mental State Examination (K-MMSE) were used to assess concurrent validity. Results: The Cronbach's alpha coefficient was 0.797, and the ICC was 0.887. Spearman's rank correlation analysis showed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively). Conclusions: Our results demonstrate that K-SCOPA-Cog exhibits good reliability and validity.

Simultaneous detection of residues of 34 beta-lactam antibiotics in livestock and fish samples through liquid chromatography-tandem mass spectrometry.

ß-Lactam is one of the widely used veterinary drugs, but simultaneous analytical methods for ß-lactam on various animal foods have not been established. In this study, we aimed to detect 34 ß-lactam antibiotics simultaneously in livestock samples (beef, pork, chicken, egg, and milk) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted using phosphate buffer/acetonitrile or water/acetonitrile and then cleaned with 150 mg of C18 and 900 mg of MgSO4. The method showed acceptable recovery and repeatability of 66.1-119% and 1.5-26%, respectively. The method was employed to monitor 127 real samples from the domestic market to confirm its applicability, and no ß-lactam residues were detected. It was also applied to other matrices (eel, flat fish, and shrimp) and showed acceptable recovery (62.1-120%) and repeatability (1.0-28%). The method is expected to improve the efficiency of monitoring veterinary drug residues in domestic livestock products and fishery foods.

Higher Physical Activity is Associated with Reduced Lower Urinary Tract Symptoms in Korean Men.

PURPOSE: Identifying and managing risk factors for lower urinary tract symptoms (LUTS) is crucial because it impacts the quality of life of elderly individuals. Lifestyle factors, including physical activity (PA), and their relationship with LUTS have not been well studied. This objective of this study was to investigate the association between PA and LUTS. MATERIALS AND METHODS: A total of 7,296 men were included in this cross-sectional study. PA was quantified in metabolic equivalent (MET)-hours per week, and LUTS severity was assessed using the international prostate symptom score. Logistic regression was used to analyze the association between PA and LUTS, including voiding and storage symptoms. RESULTS: The average age of the participants was 57.8 years, and the prevalence of LUTS was 41.3%. After adjusting for potential confounders, PA was inversely associated with the prevalence and severity of moderate-to-severe LUTS, showing a dose-response pattern (all p for trend <0.01). Compared to the minimal activity group, which engaged in <5 MET-hours per week of PA, the odds ratios for moderate to severe LUTS were 0.83 (95% confidence interval [CI]: 0.72-0.97) for men engaging in 15-30 MET-hours per week, 0.82 (95% CI: 0.71-0.95) for 30-60 MET-hours per week, and 0.72 (95% CI: 0.62-0.84) for ≥60 MET-hours per week. The possible protective effect of PA was still observed in the additional analysis for voiding and storage symptoms showing the same dose-response pattern (all p for trend <0.01). CONCLUSIONS: A higher PA level was associated with a lower prevalence and severity of total, voiding, and storage LUTS in a dose-dependent manner in Korean men.

Squamous Cell Carcinoma Arising From Epidermal Cyst: A Case Series of 9 Patients With a Literature Review.

ABSTRACT: Epidermal cysts are among the most common benign subcutaneous tumors. However, malignant transformation of benign epidermal cysts into squamous carcinomas has been reported. Owing to its low incidence rate, the clinical and pathological features of this condition are not well understood. This study aimed to analyze the clinical and pathological characteristics of the malignant transformation of epidermal cysts, which could suggest an appropriate treatment strategy. We conducted a retrospective study of 9 patients diagnosed with squamous cell carcinoma arising from epidermal cysts. All patients underwent surgical excision, and clinical information regarding patient demographics, tumor characteristics, treatment, and outcomes was analyzed. The average age at diagnosis was 57.3 years, with an average latency period of 15.4 years. Five patients had undergone prior cyst excision or drainage, with an average of 2.3 episodes of recurrence. Surgical excision was the primary treatment in all cases, and 2 patients with margin involvement at the final pathology underwent re-excision with additional resection margins. No recurrence was observed during the follow-up period. Four patients had immune dysregulation due to an underlying chronic kidney disease or cancer. Our study emphasizes the need for increased awareness of squamous cell carcinoma arising from epidermal cysts in patients with a history of cyst existence or recurrence, especially those with immune deficiencies. We expect these findings to contribute to early suspicion of malignant transformation and guide adequate clinical decision-making.

Effect of Remimazolam- versus Propofol-Based Total Intravenous General Anesthesia on Intraoperative Hemodynamic Stability for Major Spine Surgery in the Prone Position: A Randomized Controlled Trial.

Background and Objectives: Remimazolam offers advantages over propofol in terms of hemodynamic stability. However, it remains unclear whether remimazolam-based total intravenous anesthesia (TIVA) can reduce intraoperative hypotension compared to propofol-based TIVA, especially after prone positioning. In this study, we compared the effects of remimazolam- and propofol-based TIVA on intraoperative hemodynamic stability in patients undergoing surgery in the prone position. Materials and Methods: This study randomly assigned patients undergoing major spinal surgery in the prone position to the propofol or remimazolam group. Target-controlled infusion (2-3.5 µg/mL for induction and 2-3 µg/mL for maintenance) was used in the propofol group and continuous infusion (6 mg/kg/h for induction and 1-2 mg/kg/h for maintenance) was used in the remimazolam group; target-controlled infusion (3-5 ng/mL) of remifentanil was performed in both groups. The primary outcomes were the incidence of hypotensive episodes during the first hour after prone positioning. The secondary outcomes included the incidence of severe hypotension and the total amount of inotropic or vasopressor medication. Systolic and mean arterial pressure, heart rate, cardiac index and output, stroke volume, stroke volume variation, and pleth variability index were also evaluated. These variables were recorded per minute for the first 10 min after prone positioning, and every 10 min thereafter. Results: The study enrolled 94 patients (47 patients in each group). The incidence of hypotension or severe hypotension did not differ significantly between the two groups during the first hour after prone positioning. The total amount of ephedrine administered during the first hour after prone positioning was lesser (p = 0.020) and the mean arterial pressure during the initial 10 min after prone positioning was higher in the remimazolam group (p = 0.003). Conclusions: Our study uncovered no significant differences in the incidence of hypotension between remimazolam- and propofol-based TIVA in patients undergoing major spine surgery in prone position.

Direct-write 3D printing of plasmonic nanohelicoids by circularly polarized light.

Chiral plasmonic surfaces with 3D "forests" from nanohelicoids should provide strong optical rotation due to alignment of helical axis with propagation vector of photons. However, such three-dimensional nanostructures also demand multi-step nanofabrication, which is incompatible with many substrates. Large-scale photonic patterns on polymeric and flexible substrates remain unattainable. Here, we demonstrate the substrate-tolerant direct-write printing and patterning of silver nanohelicoids with out-of-plane 3D orientation using circularly polarized light. Centimeter-scale chiral plasmonic surfaces can be produced within minutes using inexpensive medium-power lasers. The growth of nanohelicoids is driven by the symmetry-broken site-selective deposition and self-assembly of the silver nanoparticles (NPs). The ellipticity and wavelength of the incident photons control the local handedness and size of the printed nanohelicoids, which enables on-the-fly modulation of nanohelicoid chirality during direct writing and simple pathways to complex multifunctional metasurfaces. Processing simplicity, high polarization rotation, and fine spatial resolution of the light-driven printing of stand-up helicoids provide a rapid pathway to chiral plasmonic surfaces, accelerating the development of chiral photonics for health and information technologies.

Thickness of melanocytes in giant congenital melanocytic nevus for complete surgical excision: clinicopathological evaluation of 117 lesions according to the area and size.

BACKGROUND: Giant congenital melanocytic nevi (GCMN) are usually defined as nevi that exceed 20 cm in maximal diameter or 15% of the total body surface area. There have been reports of life-long malignant change risks arising from GCMN, leading to surgical excision of GCMN. This study aims to evaluate the thickness of melanocytes based on clinical factors in order to provide objective information for the complete resection of the lesion. METHODS: Overall, 75 patients diagnosed with GCMN between 2000 and 2021 were included, and their clinical records were collected retrospectively. 117 pathologic slides obtained during excision were reviewed to measure nevus thickness. Clinical factors were assessed with a generalized estimated equation model for association with nevus thickness. RESULTS: The thickness of nevus was significantly associated with the location and size. Nevus thickness was more superficial in the distal extremity than in the head and trunk (P = 0.003 [head]; P < 0.001 [trunk]; P = 0.091 [Proximal extremity]). Nevi sized 60 cm or more were significantly deeper than those measuring 20-29.9 cm (P = 0.035). An interaction between size and location existed (P < 0.001). Trunk and distal extremity lesions consistently exhibited uniform thickness regardless of lesion size, whereas head and proximal extremity lesions showed variations in thickness based on lesion size. CONCLUSION: GCMNs have differences in thickness according to location and size. Therefore, it is necessary to devise an approach optimized for each patient to treat GCMN. In the study, it was emphasized that the thickness of GCMN is correlated with clinical factors, specifically the location and size of the nevus. Consequently, these findings underscore the need for individualized treatment plans for effective surgical intervention.

A Nationwide Study on HER2-low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols.

Purpose: Notable effectiveness of trastuzumab deruxtecan (T-DXd) in patients with HER2-low advanced breast cancer (BC) has focused pathologists' attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results. Materials and Methods: The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected. Results: Total 11,416 patients from twenty-five institutions included in this study. Of these patients, 40.7% (range: 6.0%-76.3%) were classified as HER2-zero, 41.7% (range: 10.5%-69.1%) as HER2-low, and 17.5% (range: 6.7%-34.0%) as HER2-positive. HER2-low tumors were associated with positive ER and PR statuses (p<0.001 and p<0.001, respectively). Antigen retrieval times (≥ 36 min vs. < 36 min) and antibody incubation times (≥ 12 min vs. < 12 min) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy (CNB) and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3259) of the patients. Conclusion: The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Hybrid Lymphovenous Anastomosis Surgery Guided by Intraoperative Mesenteric Intranodal Lymphangiography for Refractory Nontraumatic Chylous Ascites: A Case Report.

Refractory chylous ascites can cause significant nutritional and immunologic morbidity, but no clear treatment has been established. This article introduces a case of a 22-year-old female patient with an underlying lymphatic anomaly who presented with refractory chylous ascites after laparoscopic adnexectomy for ovarian teratoma which aggravated after thoracic duct embolization. Ascites (>3,000 mL/d) had to be drained via a percutaneous catheter to relieve abdominal distention and consequent dyspnea, leading to significant cachexia and weight loss. Two sessions of hybrid lymphovenous anastomosis (LVA) surgery with intraoperative mesenteric lymphangiography guidance were performed to decompress the lymphatics. The first LVA was done between inferior mesenteric vein and left para-aortic enlarged lymphatics in a side-to-side manner. The daily drainage of chylous ascites significantly decreased to 130 mL/day immediately following surgery but increased 6 days later. An additional LVA was performed between right ovarian vein and enlarged lymphatics in aortocaval area in side-to-side and end-to-side manner. The chylous ascites resolved subsequently without any complications, and the patient was discharged after 2 weeks. The patient regained weight without ascites recurrence after 22 months of follow-up. This case shares a successful experience of treating refractory chylous ascites with lymphatic anomaly through LVA, reversing the patient's life-threatening weight loss. LVA was applied with a multidisciplinary approach using intraoperative mesenteric lipiodol, and results showed the possibility of expanding its use to challenging problems in the intraperitoneal cavity.

Clinical Workflow of Cone Beam Computer Tomography-Based Daily Online Adaptive Radiotherapy with Offline Magnetic Resonance Guidance: The Modular Adaptive Radiotherapy System (MARS).

PURPOSE: The Ethos (Varian Medical Systems) radiotherapy device combines semi-automated anatomy detection and plan generation for cone beam computer tomography (CBCT)-based daily online adaptive radiotherapy (oART). However, CBCT offers less soft tissue contrast than magnetic resonance imaging (MRI). This work aims to present the clinical workflow of CBCT-based oART with shuttle-based offline MR guidance. METHODS: From February to November 2023, 31 patients underwent radiotherapy on the Ethos (Varian, Palo Alto, CA, USA) system with machine learning (ML)-supported daily oART. Moreover, patients received weekly MRI in treatment position, which was utilized for daily plan adaptation, via a shuttle-based system. Initial and adapted treatment plans were generated using the Ethos treatment planning system. Patient clinical data, fractional session times (MRI + shuttle transport + positioning, adaptation, QA, RT delivery) and plan selection were assessed for all fractions in all patients. RESULTS: In total, 737 oART fractions were applied and 118 MRIs for offline MR guidance were acquired. Primary sites of tumors were prostate (n = 16), lung (n = 7), cervix (n = 5), bladder (n = 1) and endometrium (n = 2). The treatment was completed in all patients. The median MRI acquisition time including shuttle transport and positioning to initiation of the Ethos adaptive session was 53.6 min (IQR 46.5-63.4). The median total treatment time without MRI was 30.7 min (IQR 24.7-39.2). Separately, median adaptation, plan QA and RT times were 24.3 min (IQR 18.6-32.2), 0.4 min (IQR 0.3-1,0) and 5.3 min (IQR 4.5-6.7), respectively. The adapted plan was chosen over the scheduled plan in 97.7% of cases. CONCLUSION: This study describes the first workflow to date of a CBCT-based oART combined with a shuttle-based offline approach for MR guidance. The oART duration times reported resemble the range shown by previous publications for first clinical experiences with the Ethos system.

Predictive cut-off values for the triglyceride-to-high-density lipoprotein cholesterol ratio to predict metabolic syndrome in the middle-aged Korean population.

BACKGROUND AND AIMS: The triglyceride-to-high density lipoprotein cholesterol (TG/HDL) ratio is associated with insulin resistance related diseases, including metabolic syndrome (MetS). However, specific TG/HDL values that can predict MetS have not been well identified. In this study, we analyzed both cross-sectional and longitudinal data from two national Korean datasets to obtain TG/HDL cut-off values that can identify MetS and predict its occurrence. METHODS AND RESULTS: To distinguish the presence and occurrence of MetS, the cut-off values were determined using the maximum F-score calculated through a logistic regression analysis. To predict new-onset MetS within 10 years, Cox proportional hazard models were used to consider the time of occurrence. The TG/HDL cut-off values of 3.97, 3.24, and 3.24 were optimal for identifying current MetS and predicting new-onset MetS within 10 years and five years, respectively, in Korean men. In Korean women, the optimal values for each task were 3.18, 2.38, and 2.26, respectively. CONCLUSIONS: We suggest the TG/HDL ratio as a potential candidate predictor for MetS. Therefore, we anticipate that future studies will apply individual lipid levels as well as their combinatory values to establish models that predict the prevalence and occurrence of MetS, diabetes, and cardiovascular disease.

Daily AI-Based Treatment Adaptation under Weekly Offline MR Guidance in Chemoradiotherapy for Cervical Cancer 1: The AIM-C1 Trial.

(1) Background: External beam radiotherapy (EBRT) and concurrent chemotherapy, followed by brachytherapy (BT), offer a standard of care for patients with locally advanced cervical carcinoma. Conventionally, large safety margins are required to compensate for organ movement, potentially increasing toxicity. Lately, daily high-quality cone beam CT (CBCT)-guided adaptive radiotherapy, aided by artificial intelligence (AI), became clinically available. Thus, online treatment plans can be adapted to the current position of the tumor and the adjacent organs at risk (OAR), while the patient is lying on the treatment couch. We sought to evaluate the potential of this new technology, including a weekly shuttle-based 3T-MRI scan in various treatment positions for tumor evaluation and for decreasing treatment-related side effects. (2) Methods: This is a prospective one-armed phase-II trial consisting of 40 patients with cervical carcinoma (FIGO IB-IIIC1) with an age ≥ 18 years and a Karnofsky performance score ≥ 70%. EBRT (45-50.4 Gy in 25-28 fractions with 55.0-58.8 Gy simultaneous integrated boosts to lymph node metastases) will be accompanied by weekly shuttle-based MRIs. Concurrent platinum-based chemotherapy will be given, followed by 28 Gy of BT (four fractions). The primary endpoint will be the occurrence of overall early bowel and bladder toxicity CTCAE grade 2 or higher (CTCAE v5.0). Secondary outcomes include clinical feasibility, quality of life, and imaging-based response assessment.

Re-evaluation of a microbiological acceptable daily intake for tylosin based on its impact on human intestinal microflora.

As veterinary drugs available for fish is very restricted, there is growing trials for repurposing livestock drugs as aquatic animal drugs. Tylosin is one of the most effective antibiotics to treat bacterial infections approved for livestock, and would be used in fish. Hence, we investigated the toxicological and microbiological aspects of tylosin to establish health-based guidance value (HBGV) and maximum residue limit (MRL) in fishes, and reevaluated the microbiological acceptable daily intake (mADI) based on updated relevant data and international guildeline. Lastly, exposure assessment was performed to confirm the appropriateness of MRL. By investigating available microbiologcial studies on tylosin, the microbiological point of departure was determined as 0.308 µg/mL, which was mean 50% minimum inhibitory concentration (MIC50), obtained from the Food Safety Committee of Japan (FSCJ) evaluation report. Furthermore, as a factor for the derivation of mADI, the volume of colon content was recently changed to 500 mL in compliance with the International Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Products (VICH) guidelines. This was previously defined as the mass of colon content (220 g). We applied correction factor 0.224 to the mean MIC50 for tylosin in the equation of mADI, since the drug is transformed to metabolites with reduced activity prior to entering the colon and bound to fecal materials within the colon of human. The mADI was evaluated as 0.01 mg/kg bw/day. Finally, the hazard index, calculated by dividing the estimated chronic dietary exposure by mADI, did not exceed 100%, suggesting that chronic dietary exposure to tylosin residues from veterinary use was unlikely to be a public health concern. Overall, this study contributes significantly in updating HBGV by application of the concept of mADI for the first time in Korea based on the revised microbiological risk assessment guidelines and in providing scientific rationale for the risk management of veterinary drug residues in food. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-023-00179-z.

Performance Evaluation of the STANDARD i-Q COVID-19 Ag Test with Nasal and Oral Swab Specimens from Symptomatic Patients.

We evaluated the diagnostic performance of the STANDARD i-Q COVID-19 Ag Test, which was developed to detect viral antigens, using nasal and oral swabs. Sixty positive and 100 negative samples were analyzed. We determined the distribution of the Ct values according to the day of sample collection after symptom onset, the diagnostic performance of the total samples and subgroups separated by Ct value or time of sample collection, and the Ct value at which maximal accuracy was expected. No differences were observed in Ct values, except for the samples obtained on the day of symptom onset. The diagnostic sensitivity and specificity of the oral swabs were 75.0 and 100.0%, respectively, whereas those of the nasal swabs were 85.0 and 98.0%, respectively. The sensitivity was higher in samples with a high viral load collected earlier than those collected later, although the difference was not significant. False-negative results were confirmed in all samples with a Ct value ≥ 30.0. These results indicate that tests using oral and nasal swabs are helpful for diagnosing acute symptomatic cases with suspected high viral loads. Our tests exhibited relatively low sensitivity but high specificity rates, indicating the need to assess negative antigen test results.