ABSTRACT
Accidental swallowing of press-through package (PTP) sheets that could cause esophageal perforation is commonly encountered in emergency departments requiring early detection and removal. We report a case in which an accidentally swallowed PTP sheet was removed from the esophagus using a detachable snare after usual endoscopic methods proved ineffective. A Japanese woman in her 60s visited the emergency department with a persistent sore throat. Cervicothoracic computed tomography revealed presence of a PTP sheet in the cervical esophagus, and emergency endoscopy was performed. Pre-endoscopy simulations using a sheet identical to the one swallowed by the patient indicated that the sheet would not have been retrievable using an overtube (its inner diameter was smaller than the sheet's diameter) and grasping forceps (they slipped off the sheet). It was successfully removed using a detachable snare, a device normally employed in colorectal polypectomy, allowing us to ligate the end of the sheet and pull it into the overtube. To the best of our knowledge, this is the first report of endoscopic removal of a PTP sheet from the esophagus using a detachable snare. We suggest that this novel method would facilitate removal of esophageal PTP sheets.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Real-time RT-PCR is the most commonly used method for COVID-19 diagnosis. However, serological assays are urgently needed as complementary tools to RT-PCR. Hachim et al. 2020 and Burbelo et al. 2020 demonstrated that anti-nucleocapsid(N) SARS-CoV-2 antibodies are higher and appear earlier than the spike antibodies. Additionally, cross-reactive antibodies against N protein are more prevalent than those against spike protein. We developed a less cross-reactive immunoglobulin G (IgG) indirect ELISA by using a truncated recombinant SARS-CoV-2 N protein as assay antigen. A highly conserved region of coronaviruses N protein was deleted and the protein was prepared using an E. coli protein expression system. A total of 177 samples collected from COVID-19 suspected cases and 155 negative control sera collected during the pre-COVID-19 period were applied to evaluate the assay's performance, with the plaque reduction neutralization test and the commercial SARS-CoV-2 spike protein IgG ELISA as gold standards. The SARS-CoV-2 N truncated protein-based ELISA showed similar sensitivity (91.1% vs. 91.9%) and specificity (93.8% vs. 93.8%) between the PRNT and spike IgG ELISA, as well as also higher specificity compared to the full-length N protein (93.8% vs. 89.9%). Our ELISA can be used for the diagnosis and surveillance of COVID-19.
