Intraductal oncocytic papillary neoplasm of the pancreas: clinical and radiological features compared to those of intraductal papillary mucinous neoplasm.

PURPOSE: This study aimed to characterize the clinical and imaging findings of intraductal oncocytic papillary neoplasm of the pancreas (IOPN-P) compared to those of intraductal papillary mucinous adenoma/carcinoma (IPMA/IPMC). METHODS: This multi-institutional retrospective study reviewed the clinical, imaging, and pathological findings of 21 patients with pathologically proven IOPN-P. Twenty-one computed tomography (CT) and magnetic resonance imaging, and seven 18F-fluorodeoxyglucose (FDG)-positron emission tomography were performed before surgery. The following findings were evaluated: preoperative blood test results, lesion size and location, pancreatic duct diameter, contrast-enhancement effect, bile duct and peripancreatic invasion, maximum standardized uptake (SUVmax) value, and pathological stromal invasion. RESULTS: Serum carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9) levels were significantly higher in the IPMN/IPMC group than in the IOPN-P group. Except in one patient, IOPN-P showed multifocal cystic lesions with solid components or a tumor in the main pancreatic duct (MPD) with dilatation. IOPN-P had a higher frequency of solid parts and a lower frequency of downstream MPD dilatation than IPMA. IPMC showed smaller overall cyst size, more radiological peripancreatic invasion, and worse recurrence-free and overall survival than IOPN-P. The average SUVmax value of IOPN-P was 7.5. Pathologically, 17 of the 21 IOPN-Ps had a malignant component, and six showed stromal invasion. CONCLUSION: IOPN-P shows cystic-solid lesions similar to IPMC but has lower serum CEA and CA19-9 levels, larger overall cyst size, lower frequency of peripancreatic invasion, and more favorable prognosis than IPMC. Moreover, the high FDG uptake by IOPN-Ps may be a characteristic finding of this study.

Discovery of secondary metabolites in an extractive liquid-surface immobilization system and its application to high-throughput interfacial screening of antibiotic-producing fungi.

An extractive liquid-surface immobilization (Ext-LSI) system, which consists of a hydrophobic organic solvent (an upper phase), a fungal cell-ballooned microsphere layer (a middle phase) and a liquid medium (a lower phase), is a unique interfacial cultivation system for fungi. The fungal cells growing at the interface between the organic and aqueous phases efficiently produce hydrophobic metabolites, which are continuously extracted into the organic phase, and/or hydrophilic metabolites that migrate into the aqueous phase without carbon catabolite repression and product and/or feed-back inhibitions. Application of the system to fermentation of Penicillium multicolor IAM 7153 and Trichoderma atroviride AG2755-5NM398 afforded remarkably different profiles of secondary metabolites in the organic phase compared with those in an aqueous phase in traditional submerged cultivation (SmC). Various hydrophobic metabolites exhibiting unique UV-visible spectra were accumulated into the organic phase. The system was applied to a novel interfacial screening system of antibiotic-producing fungi. Compared with the SmC, the interfacial cultivation system exhibited some interesting and important advantages, such as the higher accumulation of hydrophobic secondary metabolites, the lack of requirement for shaking and troublesome solvent extraction, and the small scale of the vessels (medium, 5 ml; dimethylsilicone oil, 1 ml), as well as the significantly different metabolite profiles. The interfacial screening system yielded a high incidence of antimicrobial activity, with 21.9% of the fungi tested exhibiting antifungal activity against Pichia anomala NBRC 10213. This novel interfacial high-throughput screening approach has the potential to discover new biologically active secondary metabolites even from strains previously found to be unproductive.