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Electrosurgical unit (ESU) is a critical piece of equipment in any endoscopy rooms because is used in the ma- jority of endoscopic therapeutic procedures. However, many endoscopists are not well-trained on their use and their physical bases are usually not properly studied or understood. A good understanding of the principles of electrosurgery and various configurations available in the ESU is essential for the effective and safe use during endoscopy. The aims of these article are to: (1) expose physical principles relevant to the understanding of elec- trosurgery during endoscopy; (2) describe and provide practical recommendations regarding two ESU that are commonly in use; (3) review usually factors relevant to commonly performed therapeutic procedures, including polypectomy, sphincterotomy, contact thermal hemostasis, argon plasma coagulation, etc. (4) discuss the clinical relevance of technologies recently implemented in newer electrosurgical units and future perspectives with the artificial intelligence.

La unidad electroquirúrgica (UEQ) es un equipo fundamental en cualquier sala de endoscopia, ya que se utiliza en la mayoría de los procedimientos terapéuticos. Sin embargo, muchos endoscopistas no están del todo capacitados en su uso y sus bases físicas no suelen estudiarse ni comprenderse adecuadamente. Un buen conocimiento de los principios electroquirúrgicos y de las diversas configuraciones disponibles en la UEQ es esencial para un uso eficaz y seguro durante la endoscopia. Los objetivos de este artículo son: (1) Exponer los principios físicos relevantes de la electrocirugía durante la endoscopia; (2) Describir y proporcionar recomendaciones prácticas con respecto a las dos UEQ más comúnmente utilizadas; (3) Revisar los factores generalmente relevantes para los procedimientos terapéuticos que se realizan con frecuencia, incluida la polipectomía, la esfinterotomía, la hemostasia térmica de contacto, la coagulación con argón plasma, etc. (4) Analizar la relevancia clínica de las tecnologías implementadas recientemente en las UEQ más nuevas y las perspectivas futuras con el advenimiento de la inteligencia artificial.

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BACKGROUND & AIMS: Despite the significant advances made in the diagnosis and treatment of Barrett's esophagus (BE), there is still a need for standardized definitions, appropriate recognition of endoscopic landmarks, and consistent use of classification systems. Current controversies in basic definitions of BE and the relative lack of anatomic knowledge are significant barriers to uniform documentation. We aimed to provide consensus-driven recommendations for uniform reporting and global application. METHODS: The World Endoscopy Organization Barrett's Esophagus Committee appointed leaders to develop an evidence-based Delphi study. A working group of 6 members identified and formulated 23 statements, and 30 internationally recognized experts from 18 countries participated in 3 rounds of voting. We defined consensus as agreement by ≥80% of experts for each statement and used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool to assess the quality of evidence and the strength of recommendations. RESULTS: After 3 rounds of voting, experts achieved consensus on 6 endoscopic landmarks (palisade vessels, gastroesophageal junction, squamocolumnar junction, lesion location, extraluminal compressions, and quadrant orientation), 13 definitions (BE, hiatus hernia, squamous islands, columnar islands, Barrett's endoscopic therapy, endoscopic resection, endoscopic ablation, systematic inspection, complete eradication of intestinal metaplasia, complete eradication of dysplasia, residual disease, recurrent disease, and failure of endoscopic therapy), and 4 classification systems (Prague, Los Angeles, Paris, and Barrett's International NBI Group). In round 1, 18 statements (78%) reached consensus, with 12 (67%) receiving strong agreement from more than half of the experts. In round 2, 4 of the remaining statements (80%) reached consensus, with 1 statement receiving strong agreement from 50% of the experts. In the third round, a consensus was reached on the remaining statement. CONCLUSIONS: We developed evidence-based, consensus-driven statements on endoscopic landmarks, definitions, and classifications of BE. These recommendations may facilitate global uniform reporting in BE.

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What should be done next? Is the stricture benign? Is it resectable? Should I place a stent? Which one? These are some of the questions one ponders when dealing with biliary strictures. In resectable cases, ongoing questions remain as to whether the biliary tree should be drained prior to surgery. In palliative cases, the relief of obstruction remains the main goal. Options for palliative therapy include surgical bypass, percutaneous drainage, and stenting or endoscopic stenting (transpapillary or via an endoscopic ultrasound approach). This review gathers scientific foundations behind these interventions. For operable cases, preoperative biliary drainage should not be performed unless there is evidence of cholangitis, there is delay in surgical intervention, or intense jaundice is present. For inoperable cases, transpapillary stenting after sphincterotomy is preferable over percutaneous drainage. The use of plastic stents (PS) has no benefit over Self-Expandable Metallic Stents (SEMS). In case transpapillary drainage is not possible, Endoscopic Ultrasonography- (EUS-) guided drainage is still an option over percutaneous means. There is no significant difference between the types of SEMS and its indication should be individualized.

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A thermostable lipase was partially purified from the culture supernatant of a thermophilic Bacillus sp. The enzyme is optimally active at 60ºC and pH 8.0. The enzyme showed enhancement in activity in presence of benzene or hexane (30 percent v/v each). The activity (assayed by determining the release of pNP from pNP laurate) was stimulated up to 60 percent of these solvents in enzyme reaction mixture. The catalytic properties of this thermostable enzyme can be further improved via the use of different immobilization techniques and reaction conditions. Enzyme was immobilized on different solid supports and their enzyme activity and stability was compared. The enzyme was adsorbed on silica and HP-20 beads followed by cross-linking with gluteraldehyde on HP-20, which improved the thermostability of enzyme. The optimum pH (pH 8.5) was nearly same for aqueous and immobilized enzyme while optimum temperature was nearly 5ºC higher in case of immobilized enzyme. The immobilized/cross linked enzyme was more thermostable at 70 and 80ºC in comparison to aqueous and surface adsorbed lipase on silica and HP-20. The optimum temperature for esterification reactions was determined to be 60-65ºC. Half-life of immobilized lipase was nearly 2.5 x higher than the aqueous enzyme at 70ºC. Esterification of methanol and oleic acid to methyl oleate by immobilized enzyme was studied in detail.