A cell wall lytic enzyme of Chlamydomonas reinhardtii has been purified and identified as a single glycopolypeptide subunit of 62 kDa by SDS-polyacrylamide gel electrophoresis. It is released into culture medium by mating gametes as a large aggregate of subunits. The purified enzyme shows a pH optimum at about 7.5 and 35°C. Metal ion chelators and SH-blocking agents inhibit the activity. The activity is also diminished by az-macroglobulin. Chlamydomonas reinhardtii Cell wallLytic enzyme Gamete Mating Glycopolypeptide

Background and Aims: Endoscopic submucosal dissection (ESD) is a well-established minimally invasive treatment for early gastric cancer. To heal ESD-induced ulcers, we commonly prescribe proton pump inhibitors (PPIs). Vonoprazan is our new choice, which is reported to have a stronger and longer acid inhibitory effect than existing PPIs. Here, we aimed to evaluate the efficacy of vonoprazan for healing ESD-induced ulcers compared with rabeprazole. Methods: We reviewed 190 patients who underwent ESD before and after we switched the acid secretion inhibitor from rabeprazole to vonoprazan. We evaluated scarring and reduction rates at 4 weeks after ESD. Results: Scarring rates were not different between vonoprazan and rabeprazole (31.7 vs. 18.9%; p = 0.07). However, for ulcers ≤35 mm, vonoprazan was superior to rabeprazole (42.2 vs. 19.2%; p < 0.05). Reduction rates were superior for vonoprazan compared with rabeprazole (93.0 vs. 90.4%; p < 0.05). In multivariate analysis, vonoprazan was superior to rabeprazole for ulcer scarring (OR 2.21; p < 0.05), and ulcer location in the lower-third of the stomach had higher risk of incomplete scarring (OR 0.37; p < 0.05). Conclusion: Vonoprazan was superior to rabeprazole for healing ESD-induced ulcers.

The diagnosis of gastric metastasis from lung cancer is relatively rare in living patients. We describe a case of Type 4 tumor-like metastasis due to primary lung cancer diagnosed with immunohistochemical staining while the patient was alive. A 68-year-old man was admitted to our hospital because of epigastric pain. Gastrointestinal endoscopy revealed a Type 4 tumor and the histological examination showed poorly differentiated adenocarcinoma. His chest X-ray showed mass shadow in the right upper lung field. The resected specimens showed moderately differentiated adenocarcinoma., The diagnosis of gastric metastasis from lung cancer was made by immunohistochemical staining of the lung and gastric tumors which showed positive staining for Thyroid transcriptional factor-1. Diagnosis of gastric metastasis, especially Type 4 metastasis by lung cancer is difficult. However, immunohistochemical staining is very helpful for diagnosis of primary lung cancer metastasis at sites such as the gastrointestinal tract which are not normally prone to metastatis.

Background: In recent years, effective outcomes of endoscopic submucosal dissection (ESD) for esophagogastric junction cancer including short-segment Barrett’s esophagus (SSBE) cancer have been reported. However, the efficacy of ESD for long-segment Barrett’s esophagus (LSBE) cancer is unknown. Aim: To clarify the treatment outcomes of ESD for LSBE cancer versus SSBE cancer. Methods: A total of 86 patients with 91 superficial Barrett’s esophageal adenocarcinomas who underwent ESD were enrolled; of these, 68 had underlying SSBE and 18 had LSBE. Procedure outcomes and prognosis were compared. Results: There was no significant difference in age and tumor diameter among patients. The only complication observed was stricture, but it was not significant (2 vs. 9%). No significant difference was observed in the negative horizontal margin rates (94.1 vs. 95.7%), R0 resection rates (83.8 vs. 82.6%), curative resection rates (72.1 vs. 73.9%), and noncurative factors. Both LSBE and SSBE cancer showed favorable 3-year overall survival rates (95.0 vs. 94.4%) in the median observation period of 28.5 months. Conclusions: ESD for LSBE cancer achieved procedure outcomes and short-term prognosis comparable to SSBE. ESD has the potential to be an effective therapeutic option for esophageal neoplasms in patients with LSBE.

Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic tumor belonging to a newly recognized entity that is coined in the 2010 WHO classification. We present a case of ITPN-associated microinvasive adenocarcinoma that developed in an asymptomatic 78-year-old patient. The tumor demonstrated all the clinical, radiological, and pathological characteristics of ITPN, but it differs from other reported cases of ITPN in molecular analysis, which revealed a somatic mutation in BRAF (c.1799T>A; p.V600E) but no mutation in PIK3CA. Post-operative recurrence was discovered 34 months after tumor resection with negative margins and a 6-month course of adjuvant chemotherapy. To the best of our knowledge, this is the first case of ITPN with BRAF mutation. This case suggests that an activation of RAS-mitogen-activated protein kinase signaling pathway may play a role in development of some of ITPNs. A possible mechanism of tumor recurrence in ITPN is also discussed. Further case series with molecular study are awaited to delineate the clinicopathological and molecular characteristics of ITPN.