Comparative evaluation of nasopharyngeal swab and saliva specimens for the molecular detection of SARS-CoV-2 RNA in Japanese patients with COVID-19.

Considering the issues of shortage of medical resources and the invasiveness and infection risk involved in the collection of nasopharyngeal swab specimens, there is a need for an effective alternative test specimen for SARS-CoV-2 RNA detection. Here, we investigated suitability of saliva as a non-invasively obtained specimen for molecular detection of SARS-CoV-2 RNA in Japanese patients with COVID-19. In total, 28 paired clinical specimens of saliva and nasopharyngeal swabs were collected from 12 patients at various time points after symptom onset. Each specimen was assayed using reverse transcription real-time polymerase chain reaction (rRT-PCR) on the BD MAX open system using primers and probes targeting the N-gene. The saliva and nasopharyngeal swab specimens showed 19 and 15 positive results, respectively. No invalid (PCR inhibition) result was observed for any specimen. The qualitative results of each specimen obtained in the period immediately after symptom onset were similar. Three convalescent patients presented saliva-positive results, whereas their nasopharyngeal swabs were negative at four different time points, suggesting that saliva may be superior to nasopharyngeal swabs in terms of obtaining stable assay result of SARS-CoV-2. In conclusion, our results suggest that saliva can potentially serve as an alternative to nasopharyngeal swabs as a specimen for SARS-CoV-2 rRT-PCR. As saliva can be collected by patients themselves, it may be an effective way to overcome the shortage of personal protective equipment and specimen sampling tools.

[Hepatic arterial infusion and occlusion technique for the evaluation of the hepatic resection to control the local liver tumor].

We report 2 cases of metachronous liver metastases from gastric cancer and 1 case of hepatocellular carcinoma (HCC) that are treated with a hepatic arterial infusion (HAI) to control the progression of local liver tumor. The treatments consist of HAI of epirubicin and mitomycin C plus degradable starch microspheres (DSM) to achieve temporary vascular occlusions. Hepatic resections were not performed in all cases because of the appearance of multiple liver metastases, or the hepatic vascular occlusion in 2 cases of gastric cancer, and the liver damage in the case of HCC. Therefore, HAI with DSM is useful for the evaluation of the hepatic resection in controlling of the local liver tumor.