Miguel Burch - Academia.edu (original) (raw)
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Papers by Miguel Burch
Gastroenterology, 2015
acted as a speaker bureau member and has received speaking honoraria from EndoGastric Solutions. ... more acted as a speaker bureau member and has received speaking honoraria from EndoGastric Solutions. Brant Oelschlager is a consultant and has received research grant from EndoGastric Solutions. Kevin Reavis is a consultant for EndoGastric Solutions. Eric Hungness received an honorarium as part of being Northwestern University faculty for a surgical training course with Baxter. The remaining authors disclose no conflicts.
American journal of physiology. Endocrinology and metabolism, Jan 15, 2014
The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hy... more The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hyperglycemia, and hormones such as glucagon-like peptide-1 (GLP-1). We have reported previously that activation of hepatoportal sensors by intraportal infusion of glucose and GLP-1 or by subcutaneous administration of GLP-1 receptor activator exenatide and of intraportal glucose improved glycemia independent of corresponding changes in pancreatic hormones. It is not clear whether this effect is mediated via the portal vein (PV) or by direct action on the liver itself. To test whether receptors in the PV mediate exenatide's beneficial effect on glucose tolerance, we performed 1) paired oral glucose tolerance tests (OGTT) with and without exenatide and 2) intravenous glucose tolerance tests before and after PV denervation in canines. Denervation of the portal vein affected oral glucose tolerance; post-denervation (POST-DEN) OGTT glucose and insulin AUC were 50% higher than before denerv...
The Journal of Thoracic and Cardiovascular Surgery, 2012
Objective: Transoral incisionless fundoplication (TIF) is a promising approach for gastroesophage... more Objective: Transoral incisionless fundoplication (TIF) is a promising approach for gastroesophageal reflux disease (GERD) that may decrease morbidity compared with conventional antireflux procedures. We report our initial experience with this minimally invasive approach.
Endocrinology, 2014
A major issue of in the treatment of diabetes is the risk of hypoglycemia. Hypoglycemia is detect... more A major issue of in the treatment of diabetes is the risk of hypoglycemia. Hypoglycemia is detected both centrally and peripherally in the porto-hepatic area. The portal locus for hypoglycemic detection was originally described using the "local irrigation of the liver" approach in a canine model. Further work using portal vein denervation (DEN) in a rodent model characterized portal hypoglycemic sensing in detail. However, recent controversy about the relevance of rodent findings to large animals and humans prompted us to investigate the effect of portal DEN on the hypoglycemic response in the canine, a species with multiple similarities to human glucose homeostasis. Hypoglycemic hyperinsulinemic clamps were performed in male canines, before (PRE) and after (POST) portal vein DEN or sham surgery (CON, control). Insulin (30 pmol/kg·min) and glucose (variable) were infused to slowly decrease systemic glycemia to 50 mg/dL over 160 minutes. The average plasma glucose during clamp steady state was: 2.9 ± 0.1 mmol DEN-PRE, 2.9 ± 0.2 mmol DEN-POST, 2.9 ± 0.1 mmol CON-PRE, and 2.8 ± 0.0 mmol CON-POST. There were no significant differences in plasma insulin between DEN and CON, PRE and POST experiments. The epinephrine response to hypoglycemia was reduced by 62% in DEN but not in CON. Steady-state cortisol was 46% lower after DEN but not after CON. Our study shows, in a large animal model, that surgical disconnection of the portal vein from the afferent pathway of the hypoglycemic counterregulatory circuitry results in a substantial suppression of the epinephrine response and a significant impact on cortisol response. These findings directly demonstrate an essential role for the portal vein in sensing hypoglycemia and relating glycemic information to the central nervous system.
Gastroenterology, 2015
acted as a speaker bureau member and has received speaking honoraria from EndoGastric Solutions. ... more acted as a speaker bureau member and has received speaking honoraria from EndoGastric Solutions. Brant Oelschlager is a consultant and has received research grant from EndoGastric Solutions. Kevin Reavis is a consultant for EndoGastric Solutions. Eric Hungness received an honorarium as part of being Northwestern University faculty for a surgical training course with Baxter. The remaining authors disclose no conflicts.
American journal of physiology. Endocrinology and metabolism, Jan 15, 2014
The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hy... more The hepatoportal area is an important glucohomeostatic metabolic sensor, sensing hypoglycemia, hyperglycemia, and hormones such as glucagon-like peptide-1 (GLP-1). We have reported previously that activation of hepatoportal sensors by intraportal infusion of glucose and GLP-1 or by subcutaneous administration of GLP-1 receptor activator exenatide and of intraportal glucose improved glycemia independent of corresponding changes in pancreatic hormones. It is not clear whether this effect is mediated via the portal vein (PV) or by direct action on the liver itself. To test whether receptors in the PV mediate exenatide's beneficial effect on glucose tolerance, we performed 1) paired oral glucose tolerance tests (OGTT) with and without exenatide and 2) intravenous glucose tolerance tests before and after PV denervation in canines. Denervation of the portal vein affected oral glucose tolerance; post-denervation (POST-DEN) OGTT glucose and insulin AUC were 50% higher than before denerv...
The Journal of Thoracic and Cardiovascular Surgery, 2012
Objective: Transoral incisionless fundoplication (TIF) is a promising approach for gastroesophage... more Objective: Transoral incisionless fundoplication (TIF) is a promising approach for gastroesophageal reflux disease (GERD) that may decrease morbidity compared with conventional antireflux procedures. We report our initial experience with this minimally invasive approach.
Endocrinology, 2014
A major issue of in the treatment of diabetes is the risk of hypoglycemia. Hypoglycemia is detect... more A major issue of in the treatment of diabetes is the risk of hypoglycemia. Hypoglycemia is detected both centrally and peripherally in the porto-hepatic area. The portal locus for hypoglycemic detection was originally described using the "local irrigation of the liver" approach in a canine model. Further work using portal vein denervation (DEN) in a rodent model characterized portal hypoglycemic sensing in detail. However, recent controversy about the relevance of rodent findings to large animals and humans prompted us to investigate the effect of portal DEN on the hypoglycemic response in the canine, a species with multiple similarities to human glucose homeostasis. Hypoglycemic hyperinsulinemic clamps were performed in male canines, before (PRE) and after (POST) portal vein DEN or sham surgery (CON, control). Insulin (30 pmol/kg·min) and glucose (variable) were infused to slowly decrease systemic glycemia to 50 mg/dL over 160 minutes. The average plasma glucose during clamp steady state was: 2.9 ± 0.1 mmol DEN-PRE, 2.9 ± 0.2 mmol DEN-POST, 2.9 ± 0.1 mmol CON-PRE, and 2.8 ± 0.0 mmol CON-POST. There were no significant differences in plasma insulin between DEN and CON, PRE and POST experiments. The epinephrine response to hypoglycemia was reduced by 62% in DEN but not in CON. Steady-state cortisol was 46% lower after DEN but not after CON. Our study shows, in a large animal model, that surgical disconnection of the portal vein from the afferent pathway of the hypoglycemic counterregulatory circuitry results in a substantial suppression of the epinephrine response and a significant impact on cortisol response. These findings directly demonstrate an essential role for the portal vein in sensing hypoglycemia and relating glycemic information to the central nervous system.