Background and Objective Since the initial coronavirus disease outbreak in late 2019 (COVID-19), reverse-transcription real-time polymerase chain reaction (RT-qPCR) has become the gold standard test to detect severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). However, a more sensitive and accurate diagnostic tool was required. Therefore, droplet digital polymerase chain reaction (ddPCR) was suggested as an alternative method. Here, we evaluated the performance of ddPCR to detect SARS-CoV-2 and compared it to the performance of RT-qPCR. Methods The analytical performances, including limit of blank and limit of detection, were established using positive and negative SARS-CoV-2 reference materials. A total of 366 RNA extracts (173 positive and 193 negative by RT-qPCR) were collected from four institutions and tested with a Bio-Rad SARS-CoV-2 ddPCR kit that detects the SARS-CoV-2 genome using primers for N1 and N2. Results Limit of blank was set at 0, and the limits of detection of N1 and N2 were 1.99 copies/μL and 5.18 copies/μL, respectively. Linearity was evaluated using serial dilution samples, which demonstrated good results (R²: 0.999, linear range: 5.88–6825.25 copies/μL for N1 and R²: 0.999, 5.53–5855.47 copies/μL for N2). The results of ddPCR and RT-qPCR revealed substantial agreement (Cohen’s kappa: 0.639, p < 0.01). The 63 samples with positive ddPCR but negative RT-qPCR showed low copy numbers, and 55% of them had COVID-19-related symptoms. Conclusions Droplet digital polymerase chain reaction demonstrated excellent sensitivity for SARS-Cov-2 detection and consistently agreed with the results from conventional RT-qPCR. Furthermore, ddPCR provided quantitative data that can be used to monitor changes in the viral load of patients with COVID-19.

Viral infections are a common cause of encephalitis. This study investigated the relationship between the incidence of encephalitis and that of respiratory and enteric viral infections in all age groups from 2015 to 2019, using the Health Insurance Review and Assessment (HIRA) Open Access Big Data Platform. We identified monthly incidence patterns and seasonal trends using the autoregressive integrated moving average (ARIMA). The Granger causality test was used to analyze correlations between encephalitis incidence and the positive detection rate (PDR) at 1-month intervals. A total of 42,775 patients were diagnosed with encephalitis during the study period. The incidence of encephalitis was highest in the winter (26.8%). The PDRs for respiratory syncytial virus (HRSV) and coronavirus (HCoV) were associated with the trend in encephalitis diagnosis in all age groups, with a 1-month lag period. In addition, an association with norovirus was observed in patients aged over 20 years, and with influenza virus (IFV) in patients aged over 60 years. This study found that HRSV, HCoV, IFV, and norovirus tended to precede encephalitis by 1 month. Further research is required to confirm the association between these viruses and encephalitis.

Febrile convulsion (FC) is the most common seizure disease in children, which occurs with a fever. We investigated the Korean Health Insurance Review and Assessment Service data of patients aged between 6 months and 5 years at the time of FC diagnosis. Diseases that can cause seizures with fever, such as neoplasms, metabolic disorders, nervous system disorders, cerebrovascular diseases, perinatal problems, and congenital abnormalities, were excluded. Weekly virus-positive detection rate (PDR) data were obtained from the Korea Disease Control and Prevention Agency for adenovirus, parainfluenza virus, respiratory syncytial virus (HRSV), influenza virus, coronavirus (HCoV), rhinovirus (HRV), bocavirus, metapneumovirus (HMPV), rotavirus, norovirus, and astrovirus. Using the Granger test, we then analyzed the monthly PDR and investigated the association between FC incidence and monthly PDR. We additionally identified monthly and seasonal FC incidence trends using the autoregressive integrated moving average. Between 2015 and 2019, 64,291 patients were diagnosed with FC. Annually, the incidence was the highest in May and the lowest in October. Most patients were diagnosed during the spring (26.7%). The PDRs for HRSV, HCoV, HRV, HMPV, and norovirus were associated with FC incidence after 1 month.

Background: Carnosine has antioxidative and neuroprotective properties against hypoxic-ischemic (HI) brain injury. Hypothermia is used as a therapeutic tool for HI encephalopathy in newborn infants with perinatal asphyxia. However, the combined effects of these therapies are unknown.Purpose: Here we investigated the effects of combined carnosine and hypothermia therapy on HI brain injury in neonatal rats.Methods: Postnatal day 7 (P7) rats were subjected to HI brain injury and randomly assigned to 4 groups: vehicle; carnosine alone; vehicle and hypothermia; and carnosine and hypothermia. Carnosine (250 mg/kg) was intraperitoneally administered at 3 points: immediately following HI injury, 24 hours later, and 48 hours later. Hypothermia was performed by placing the rats in a chamber maintained at 27°C for 3 hours to induce whole-body cooling. Sham-treated rats were also included as a normal control. The rats were euthanized for experiments at P10, P14, and P35. Histological and morphological analyses, in situ zymography, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assays, and immunofluorescence studies were conducted to investigate the neuroprotective effects of the various interventional treatments.Results: Vehicle-treated P10 rats with HI injury showed an increased infarct volume compared to sham-treated rats during the triphenyltetrazolium chloride staining study. Hematoxylin and eosin staining revealed that vehicle-treated P35 rats with HI injury had decreased brain volume in the affected hemisphere. Compared to the vehicle group, carnosine and hypothermia alone did not result in any protective effects against HI brain injury. However, a combination of carnosine and hypothermia effectively reduced the extent of brain damage. The results of in situ zymography, TUNEL assays, and immunofluorescence studies showed that neuroprotective effects were achieved with combination therapy only.Conclusion: Carnosine and hypothermia may have synergistic neuroprotective effects against brain damage following HI injury.

Background and objectives: Ovarian cancer is one of the leading causes of death among women worldwide. Most newly diagnosed ovarian cancer patients are diagnosed in advanced stages of the disease. Despite various treatments, most patients with advanced stage ovarian cancer, including serous ovarian cancer (the most common subtype of ovarian cancer), experience recurrence, which is associated with extremely poor prognoses. In the present study, we aimed to identify core genes involved in ovarian cancer and their associated molecular mechanisms, as well as to investigate related clinicopathological implications in ovarian cancer. Materials and methods: Three gene expression cohorts (GSE14407, GSE36668, and GSE38666) were obtained from the Gene Expression Omnibus databases to explore potential therapeutic biomarkers for ovarian cancer. Nine up-regulated and six down-regulated genes were screened. Three publicly available gene expression datasets (GSE14407, GSE36668, and GSE38666) were analyzed. Results: A total of 14 differently expressed genes (DEGs) were identified, among which nine genes were upregulated (BIRC5, CDCA3, CENPF, KIF4A, NCAPG, RRM2, UBE2C, VEGFA, and NR2F6) and were found to be significantly enriched in cell cycle regulation by gene ontology analysis. Further protein–protein interaction network analysis revealed seven hub genes among these DEGs. Moreover, Kaplan–Meier survival analysis showed that a higher expression of CDCA3 and UBE2C was associated with poor overall patient survival regardless of tumor stage and a higher tumor histologic grade. Conclusion: Altogether, our study suggests that CDCA3 and UBE2C may be valuable biomarkers for predicting the outcome of patients with advanced serous ovarian cancer.

Kyoung Bo Kim, M.D., Sunggyun Park, M.D., Jung Sook Ha, M.D., Ph.D., Namhee Ryoo, M.D., Ph.D., and Do-Hoon Kim, M.D., Ph.D.. Ann Lab Med 2022;42:497-9. https://doi.org/10.3343/alm.2022.42.4.497