Aceves, Manuel

Abstract Background Distal (ileal) metabolic bariatric surgeries (DMBS) have gained increasing adoption due to their enhanced metabolic effects. However, the absence of standardized definitions, classification, and clinical indications limits their consistent application. This consensus aimed to establish an international consensus on the definition, classification, indications, and postoperative management of DMBS. Methods A three-round modified Delphi study was conducted including international expert surgeons from 16 countries. A total of 98 statements were developed across three domains: procedural characteristics, patient selection, and postoperative follow-up. Consensus was defined as ≥75% agreement. Statements not reaching consensus were revised and resubmitted. Results Consensus was achieved on 81 statements. DMBS were defined as procedures involving gastro-ileal or duodeno-ileal bypass, emphasizing ileal stimulation as a key metabolic mechanism. Procedures with a common channel ≤350 cm, including single-anastomosis duodenal-ileal with SG (SADI-S), single anastomosis sleeve-ileal transit bipartition (SASI), sleeve gastrectomy with Roux-en-Y transit bipartition (SG+TB), and biliopancreatic diversion with duodenal switch (BPD-DS), as well as one-anastomosis gastric bypass (OAGB) with biliopancreatic limb > 50% of total small bowel length were classified as DMBS. Routine measurement of total small bowel length was strongly recommended. DMBS were considered appropriate as primary procedures in patients with BMI ≥40 kg/m² with comorbidities, a BMI ≥50–60 kg/m², irrespective of the presence of comorbidities, and as revisional options for suboptimal clinical response (SoCR), recurrent weight gain (RWG), or persistent metabolic disease. Comprehensive preoperative and multidisciplinary evaluation was deemed mandatory, and liver cirrhosis, heart failure, end-stage kidney disease, and inflammatory bowel disease were considered contraindications. Postoperative care requires lifelong multidisciplinary follow-up, with increased attention to nutritional deficiencies and supplementation. Conclusions This consensus provides a standardized framework for DMBS, supporting harmonization of practice and improved patient safety.

Abstract Structural discovery of guanine nucleotide exchange factor (GEF) protein complexes is likely to become increasingly relevant with the development of new therapeutics targeting small GTPases and development of new classes of small molecules that inhibit protein‐protein interactions. Syx (also known as PLEKHG5 in humans) is a RhoA GEF implicated in the pathology of glioblastoma (GBM). Here we investigated protein expression and purification of ten different human Syx constructs and performed biophysical characterizations and computational studies that provide insights into why expression of this protein was previously intractable. We show that human Syx can be expressed and isolated and Syx is folded as observed by circular dichroism (CD) spectroscopy and actively binds to RhoA as determined by co‐elution during size exclusion chromatography (SEC). This characterization may provide critical insights into the expression and purification of other recalcitrant members of the large class of oncogenic—Diffuse B‐cell lymphoma (Dbl) homology GEF proteins. In addition, we performed detailed homology modeling and molecular dynamics simulations on the surface of a physiologically realistic membrane. These simulations reveal novel insights into GEF activity and allosteric modulation by the plekstrin homology (PH) domain. These newly revealed interactions between the GEF PH domain and the membrane embedded region of RhoA support previously unexplained experimental findings regarding the allosteric effects of the PH domain from numerous activity studies of Dbl homology GEF proteins. This work establishes new hypotheses for structural interactivity and allosteric signal modulation in Dbl homology RhoGEFs.