Delineation of regions in the extracellular domain of follicle-stimulating hormone receptor involved in hormone binding and signal transduction

PROBLEM: To use antipeptide antibodies to potential surface-oriented regions of the extracellular domain (ECD) of the human follicle-stimulating hormone receptor (hFSHR) to delineate regions involved in FSH binding and FSH-induced signal transduction. METHOD OF STUDY: We developed and characterized antipeptide antibodies to different, potentially surface-oriented regions of the ECD of hFSHR. The ability of these antibodies to recognize the receptor was studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western blotting. The ability to modulate FSH binding and cAMP generation was studied by the radioreceptor assay and in vitro FSH bioassay respectively. RESULTS: Antipeptide antibodies to regions 15-31, 216-235, 285-300 and 327-341 hFSHR inhibited both FSH binding and cAMP production. Regions 15-31 and 216-235 were accessible to their cognate antipeptide antibodies both before and after FSH binding,. while regions 285-300 and 327-341 hFSHR were accessible only prior to FSH binding. CONCLUSIONS: Based on the observations made with respect to accessibility to antipeptide antibodies, ability of antibodies to inhibit FSH binding and the subsequent cAMP generation and kinetics of antibody binding, regions 285-300 and 327-341 hFSHR appear to be the chief FSH-binding sites, while regions 15-31 and 216-235 hFSHR serve as ancillary FSH-binding sites

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)