Embolization with or without portal vein stenting for bleeding ectopic jejunal varices in hepatopetal portal collaterals due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery.

PURPOSE: To evaluate the efficacy and safety of embolization with or without portal vein stenting for bleeding ectopic jejunal varices in the hepatopetal portal collateral due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery. MATERIALS AND METHODS: This study included consecutive patients who underwent embolization for bleeding ectopic jejunal varices in the hepatopetal collateral due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery between September 2012 and December 2020. The safety, technical and clinical success rates (no re-bleeding within 1 month) and re-bleeding-free survival after the first therapy and overall survival were assessed. RESULTS: Fourteen sessions in 11 patients were included. Four patients (7 sessions) underwent variceal embolization only, and the remaining seven patients (7 sessions) underwent portal vein stenting and variceal embolization. Technical success was achieved in all 14 sessions (100%). Clinical success was achieved in 13 of 14 sessions (92.9%). No treatment-related serious complications including liver failure were observed. One-year and 2-year re-bleeding-free survival rate after the first endovascular therapy in all 11 patients was 90.9 and 60.6%, respectively. Two patients who experienced re-bleeding had repeat embolization treatment. There was no significant difference in re-bleeding-free survival after endovascular therapy between the combination with stenting and embolization group and the embolization-only group (p = 0.13). CONCLUSION: Embolization with or without portal vein stenting of bleeding ectopic jejunal varices in the hepatopetal portal collateral due to extrahepatic portal vein occlusion or stenosis after hepatobiliary and pancreatic surgery can be considered a safe, effective, and repeatable therapy for long-term hemostasis of uncontrollable bleeding.

Low-CO2-inducible bestrophins outside the pyrenoid sustain high photosynthetic efficacy in diatoms.

Anion transporters sustain a variety of physiological states in cells. Bestrophins (BSTs) belong to a Cl- and/or HCO3- transporter family conserved in bacteria, animals, algae, and plants. Recently, putative BSTs were found in the green alga Chlamydomonas reinhardtii, where they are upregulated under low CO2 (LC) conditions and play an essential role in the CO2-concentrating mechanism (CCM). The putative BST orthologs are also conserved in diatoms, secondary endosymbiotic algae harboring red-type plastids, but their physiological functions are unknown. Here, we characterized the subcellular localization and expression profile of BSTs in the marine diatoms Phaeodactylum tricornutum (PtBST1 to 4) and Thalassiosira pseudonana (TpBST1 and 2). PtBST1, PtBST2, and PtBST4 were localized at the stroma thylakoid membrane outside of the pyrenoid, and PtBST3 was localized in the pyrenoid. Contrarily, TpBST1 and TpBST2 were both localized in the pyrenoid. These BST proteins accumulated in cells grown in LC but not in 1% CO2 (high CO2 [HC]). To assess the physiological functions, we generated knockout mutants for the PtBST1 gene by genome editing. The lack of PtBST1 decreased photosynthetic affinity for dissolved inorganic carbon to the level comparable with the HC-grown wild type. Furthermore, non-photochemical quenching in LC-grown cells was 1.5 to 2.0 times higher in the mutants than in the wild type. These data suggest that HCO3- transport at the stroma thylakoid membranes by PtBST1 is a critical part of the CO2-evolving machinery of the pyrenoid in the fully induced CCM and that PtBST1 may modulate photoprotection under CO2-limited environments in P. tricornutum.