The microwave tissue coagulator has been applied clinically with satisfactory results. In our system, 2,450‐MHz microwaves for medical use are generated and transmitted to a monopolar‐type needle electrode. This electrode is thrust directly into the liver tissue and this is repeated along the line where incision is anticipated. Between July 1980, and May 1983, this device was used in 60 patients having major hepatic resections for a variety of conditions. The average amounts of blood loss and blood transfusion were 860 ml and 416 ml, respectively. Seventeen patients did not need blood transfusions, and all cases were free from postoperative bleeding from the resected liver stump. Besides the complications similar to those occurring with other major operations, pyrexia and abdominal pain developed in some cases 2–3 weeks after this surgical procedure. These symptoms were thought to be ascribed to the microwave surgery. However, they remitted soon and the subsequent course was uneventful. All patients with benign or inflammatory diseases had a satisfactory postoperative course, and are well. Of the patients subjected to liver resection for malignant diseases, 4 (6.7%) died within a month after the operation. These findings led us to conclude that this new operative technique can be utilized safely, surely, and easily in the field of hepatic surgery.

On the basis of the ample basic knowledge acquired by repeated experiments, we applied our microwave tissue coagulator in endoscopic surgery, in a total of 59 patients with benign and malignant lesions encountered during a period of two years beginning in July, 1981. Hemostasis was achieved in 96.5% of all the cases with bleeding lesions in the digestive tract. Stenosis was alleviated in 86% of the cases with esophageal or rectal stenosis. Furthermore, the technique was successfully used for hemostasis and tumor reduction in inoperable early cancer cases. Our device is unique in that the electrode is thrust into tissue, which assures us of a satisfactory result. In this point, it must be clearly distinguished from an electrocoagulator or a laser coagulator, which is associated with a risk of injuring intact tissue. The range of coagulation is adjustable by changing the length of the monopolar antenna and electric output, and by employing a coaxial cable of appropriate thickness. In conclusion, our microwave tissue coagulator can be used easily and safely in clinical endoscopic surgery.

No abstract

The present study shows that natural killer cell-mediated cytotoxicity of BALB/c mouse spleen cells to syngeneic tumor cells was augmented by in vivo priming or in vitro stimulation with the streptococcal preparation OK432. The augmentation of spleen cell cytotoxicity to syngeneic tumor cells by in vivo priming alone with OK432 was lower than that obtained by in vitro stimulation alone with OK432. When the murine spleen cells primed in vivo with OK432 were rechallenged in vitro with OK432 at various intervals, the natural cytotoxicity was more strongly enhanced than that seen with in vitro stimulation alone. The cell surface phenotype of killer cells activated with OK432 was Thy 1+ and asialo GM1+, suggesting the activated natural killer cell. Next, mice were transplanted with syngeneic colon adenocarcinoma cells, and primed in vivo with OK432. These spleen cells were subsequently challenged in vitro with OK432. These spleen cells displayed a strong cytotoxic activity not only to the transplanted adenocarcinoma cells but also to other syngeneic tumor cells.

Rapid molecular testing for severe acute respiratory coronavirus 2 (SARS-CoV-2) variants may contribute to the development of public health measures, particularly in resource-limited areas. Reverse transcription recombinase polymerase amplification using a lateral flow assay (RT-RPA-LF) allows rapid RNA detection without thermal cyclers. In this study, we developed two assays to detect SARS-CoV-2 nucleocapsid (N) gene and Omicron BA.1 spike (S) gene-specific deletion–insertion mutations (del211/ins214). Both tests had a detection limit of 10 copies/µL in vitro and the detection time was approximately 35 min from incubation to detection. The sensitivities of SARS-CoV-2 (N) RT-RPA-LF by viral load categories were 100% for clinical samples with high (>9015.7 copies/µL, cycle quantification (Cq): < 25) and moderate (385.5–9015.7 copies/µL, Cq: 25–29.9) viral load, 83.3% for low (16.5–385.5 copies/µL, Cq: 30–34.9), and 14.3% for very low (<16.5 copies/µL, Cq: 35–40). The sensitivities of the Omicron BA.1 (S) RT-RPA-LF were 94.9%, 78%, 23.8%, and 0%, respectively, and the specificity against non-BA.1 SARS-CoV-2-positive samples was 96%. The assays seemed more sensitive than rapid antigen detection in moderate viral load samples. Although implementation in resource-limited settings requires additional improvements, deletion–insertion mutations were successfully detected by the RT-RPA-LF technique.