Chad Barnes

Microvascular Adaptations to Exercise: Protective Effect of PGC-1 Alpha

BACKGROUND Sedentary behavior and obesity are major risk factors for cardiovascular disease. Regular physical activity has independent protective effects on the cardiovascular system, but the mechanisms responsible remain elusive. Recent studies suggest that the protein peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) participates in the response to exercise training. We hypothesized that the arterioles of athletes maintain dilation to flow despite combined inhibition of multiple vasodilators, but loss of PGC-1α renders these vessels susceptible to inhibition of a single vasodilator pathway. In addition, arterioles from overweight and obese individuals will display an an exercise-like phenotype when PGC-1α is activated. METHODS Isolated arterioles from exercise-trained (ET) and from mildly overweight or obese subjects (body mass index >25) were cannulated, and changes in lumen diameter in response to graded increases in flow were recorded in the absence and presence of compounds that inhibit various endothelium-dependent vasodilators. RESULTS Microvessels of ET subjects displayed robust dilation that could not be inhibited through targeting the combination of nitric oxide, prostaglandins, and hydrogen peroxide, but were inhibited via interference with membrane hyperpolarization. Loss of PGC-1α (siRNA) in the microcirculation of ET subjects eliminates this vasodilatory robustness rendering vessels susceptible to blockade of H2O2 alone. Pharmacological activation of PGC-1α with alpha-lipoic acid in isolated microvessels from sedentary, overweight, and obese subjects increases arteriolar resistance to vasodilator blockade and protects against acute increases in intraluminal pressure. CONCLUSIONS These findings suggest that the microvascular adaptations to exercise training, and the exercise-induced protection against acute vascular stress in overweight/obese subjects, are mediated by PGC-1α.

Locally advanced pancreas cancer: Staging and goals of therapy

Background: Patients with locally advanced pancreatic cancer have historically been considered inoperable. The purpose of this report was to determine resectability rates for patients with locally advanced pancreatic cancer based on our recently described definitions of type A and type B locally advanced pancreatic cancer. Methods: An institutional prospective pancreas cancer database was queried for consecutive patients with locally advanced pancreatic cancer treated between January 2009 and June 2017. All pretreatment imaging was re‐reviewed and patients were categorized as locally advanced pancreatic cancer type A or type B. Demographics, induction therapy, resection type, and outcomes were reviewed. Results: We identified 108 consecutive patients; 12 were excluded from analysis due to the absence of available pretreatment imaging or they had not yet completed all intended neoadjuvant therapy. Of the remaining 96 patients (45 type A, 51 type B), disease progression occurred in 19 (20%) during induction therapy and 30 (31%) were deemed inoperable at final preoperative restaging. Therefore, 47 (49%) of 96 patients were taken to surgery and 40 (42%) underwent successful resection (28 [62%] of 45 type A and 12 [24%] of 51 type B); an RO resection was achieved in 32 (80%). Metastatic disease was found intraoperatively (6 at laparoscopy, 1 at laparotomy) in 7 (15%) of 47 patients. There were no mortalities; 6 (15%) patients experienced major postoperative complications. Resected patients had a median overall survival of 38.9 months. Conclusion: Locally advanced pancreatic cancer can be dichotomized into type A and B with distinctly different probabilities of completing all therapy to include surgery; thereby allowing goals of therapy to be established at the time of diagnosis. Multimodality therapy that includes surgery can be accomplished in selected patients with locally advanced pancreatic cancer and is associated with a median overall survival that approximates earlier stages of disease. (Surgery 2017;160:XXX‐XXX.)

Pancreas Adenocarcinoma and Ampullary Cancer

The incidence of periampullary tumors is increasing. Pancreatic cancer estimated to become the second leading cause of cancer related deaths by 2020. Similar to many other solid organ tumors, the management of pancreatic cancer requires a multidisciplinary team approach and the sequencing of oncologic therapies has significant impact on quality of life, treatment toxicity, and survival. This chapter will review pancreatic cancer staging and provide a framework to guide discussions regarding neoadjuvant versus adjuvant therapy for pancreatic cancer. In addition, the management of tumors of the ampulla Vatar will be contrasted with the management of pancreatic cancer.