Bradley Needleman

Visceral Adipose Inflammation in Obesity Is Associated with Critical Alterations in Tregulatory Cell Numbers

Background The development of insulin resistance (IR) in mouse models of obesity and type 2 diabetes mellitus (DM) is characterized by progressive accumulation of inflammatory macrophages and subpopulations of T cells in the visceral adipose. Regulatory T cells (Tregs) may play a critical role in modulating tissue inflammation via their interactions with both adaptive and innate immune mechanisms. We hypothesized that an imbalance in Tregs is a critical determinant of adipose inflammation and investigated the role of Tregs in IR/obesity through coordinated studies in mice and humans. Methods and Findings Foxp3-green fluorescent protein (GFP) “knock-in” mice were randomized to a high-fat diet intervention for a duration of 12 weeks to induce DIO/IR. Morbidly obese humans without overt type 2 DM (n = 13) and lean controls (n = 7) were recruited prospectively for assessment of visceral adipose inflammation. DIO resulted in increased CD3+CD4+, and CD3+CD8+ cells in visceral adipose with a striking decrease in visceral adipose Tregs. Treg numbers in visceral adipose inversely correlated with CD11b+CD11c+ adipose tissue macrophages (ATMs). Splenic Treg numbers were increased with up-regulation of homing receptors CXCR3 and CCR7 and marker of activation CD44. In-vitro differentiation assays showed an inhibition of Treg differentiation in response to conditioned media from inflammatory macrophages. Human visceral adipose in morbid obesity was characterized by an increase in CD11c+ ATMs and a decrease in foxp3 expression. Conclusions Our experiments indicate that obesity in mice and humans results in adipose Treg depletion. These changes appear to occur via reduced local differentiation rather than impaired homing. Our findings implicate a role for Tregs as determinants of adipose inflammation.

Computer-Enhanced vs. Standard Laparoscopic Antireflux Surgery☆

Computer-assisted telesurgical devices have recently been approved in the United States for general surgery. To determine the safety and efficacy of these procedures, we performed a prospective trial of computer-enhanced “robotic” fundoplication compared to standard laparoscopic control procedures. Consecutive patients undergoing surgical treatment for gastroesophageal reflux were included. The operating surgeon worked at a console using a three-dimensional image and manipulated hand controls. Operative times, complications, and length of hospital stay were recorded. A standardized questionnaire was administered to evaluate symptoms. Twenty patients were entered into each group. There were no differences in age, preoperative weight, or sex. Operative times were significantly longer in the robot group (97 vs. 141 minutes). There were no complications and most patients went home the first postoperative day. At follow-up, symptoms were similar in both groups; however, there was a significant difference in the number of patients taking antisecretory medication—none in the robotic group but six in the laparoscopic group reported regular use. Computer-assisted laparoscopic antireflux surgery is safe. However, operative times are longer, with little difference in outcomes. At the current level of technology and experience, robotic antireflux surgery appears to offer little advantage over standard laparoscopic approaches.

Endoscopic management of stomal stenosis after Roux-en-Y gastric bypass

Background: In the United States, Roux-en-Y gastric bypass has evolved into the procedure of choice for clinically severe obesity. Stomal stenosis resulting in gastric outlet obstruction is a recognized complication. Endoscopic balloon dilation is often used to treat this condition. To evaluate the safety and efficacy of endoscopic management of stomal stenosis we evaluated our treatment methods and outcomes. Methods: The records of all patients undergoing Roux-en-Y gastric bypass from 1 July 2000 to 30 June 2002 were studied. Stenosis was defined as signs and symptoms of obstruction with inability to cannulate the gastrojejunostomy using an 8.5-mm diagnostic endoscope. Charts were reviewed and demographic data, operative course, symptoms, and outcomes were recorded. Results: A total of 562 patients underwent Roux-en-Y gastric bypass for obesity during the study period. Of these, 38 patients underwent endoscopic balloon dilation for stomal stenosis, for a stenosis rate of 6.8%. The average time from surgery to initial dilation was 7.7 weeks (range 3 to 24). The average number of dilations required was 2.1 (range one to six). The mean initial balloon size was 13 mm and the mean final balloon size was 16 mm. Two patients failed endoscopic dilation and proceeded to surgery, including one patient who developed pneumomediastinum and pneumothorax after dilation. All patients were relieved of their gastric outlet obstruction. The success rate for endoscopic balloon dilation was 95% with a 3% complication rate. Conclusions: In our experience, the rate of gastrojejunostomy stenosis following Roux-en-Y gastric bypass is 6.8%. Endoscopic balloon dilation is a safe and effective therapy for stomal stenosis with a high success rate. It should be considered an appropriate intervention with a low risk for reoperation.

Transgastric instrumentation and bacterial contamination of the peritoneal cavity

IntroductionNatural orifice transluminal endoscopic surgery (NOTES) is a rapidly evolving technique providing access to the peritoneum utilizing an endoscope via a natural orifice. One of the most significant requirements of this technique is the need to minimize the risk of clinically significant peritoneal contamination. We report the bacterial load and contamination of the peritoneal cavity in patients requiring a gastrotomy Roux-en-Y gastric bypass (LSRYGB).MethodsWe prospectively studied 50 patients undergoing a gastrotomy with creation of a gastrojejunostomy during LSRYGB. We recorded the patient’s proton-pump inhibitor (PPI) utilization preoperatively and sampled gastric contents without lavage. We also sampled peritoneal fluid prior to and after gastrotomy, noting the length of time the gastrotomy was open to the peritoneum. Each of the three samples was sent for bacterial colony counts, and culture with identification of species.ResultsFifty patients underwent LSRYGB with a mean operative time of 93 min. The gastrotomy was open to the peritoneal cavity for an average of 18 min. Seventeen of 50 patients were on PPIs preoperatively, resulting in a significant difference in postgastrostomy peritoneal bacterial counts. The average number of colony-forming units (CFU) of the gastric aspirate was 22,303 CFU/ml. Peritoneal aspirates obtained for examination prior to creation of a gastrotomy showed no CFUs in 44 of 50 patients. Peritoneal sampling after gastrotomy showed contamination of the abdomen with an average of 1102 CFU/ml. There was no correlation between the bacterial load in the stomach and peritoneal load after gastrotomy. No infectious complications or leaks developed. One complication of rhabdomyolysis in a patient with no peritoneal bacterial contamination developed.ConclusionsTransgastric instrumentation does contaminate the abdominal cavity but pathogens are clinically insignificant due to species or bacterial load. Patients on PPIs do have an increased bacterial load in the gastric aspirate, with no clinical significant infection.

A Potential Role for Dendritic Cell/Macrophage-Expressing DPP4 in Obesity-Induced Visceral Inflammation

Dipeptidyl peptidase-4 (DDP4) inhibitors target the enzymatic degradation of incretin peptides and represent a major advance in the treatment of type 2 diabetes. DPP4 has a number of nonenzymatic functions that involve its interaction with adenosine deaminase (ADA) and other extracellular matrix proteins. Here, we assessed the nonenzymatic role of DPP4 in regulating dendritic cell (DC)/macrophage–mediated adipose inflammation in obesity. Both obese humans and rodents demonstrated increased levels of DPP4 expression in DC/macrophage cell populations from visceral adipose tissue (VAT). The DPP4 expression increased during monocyte differentiation to DC/macrophages and with lipopolysaccharide (LPS)-induced activation of DC/macrophages. The DPP4 colocalized with membrane-bound ADA on human DCs and enhanced the ability of the latter to stimulate T-cell proliferation. The DPP4 interaction with ADA in human DC/macrophages was competitively inhibited by the addition of exogenous soluble DPP4. Knockdown of DPP4 in human DCs, but not pharmacologic inhibition of their enzymatic function, significantly attenuated the ability to activate T cells without influencing its capacity to secrete proinflammatory cytokines. The nonenzymatic function of DPP4 on DC may play a role in potentiation of inflammation in obesity by interacting with ADA. These findings suggest a novel role for the paracrine regulation of inflammation in adipose tissue by DPP4.

Computer-assisted robotic heller myotomy: initial case report.

PURPOSE Our objective was to determine the efficacy of computer-assisted robotic laparoscopic Heller myotomy. METHODS A 76-year-old woman with a significant history of achalasia was evaluated for laparoscopic Heller myotomy. The daVinci surgical system was used throughout the procedure. RESULTS Computer assistance allowed scaling of hand motions from a range of 2:1 to 5:1. Successful dissection of the esophageal musculature was accomplished, and a Toupet-type fundoplication was performed. The patient was discharged from the hospital the day after surgery with five port incisions, each <1 cm. CONCLUSIONS Telemanipulator computer-assisted surgical devices may have applications in procedures that require advanced and finely tuned motions, such as Heller myotomy. The benefits of extra magnification and three-dimensional imaging can help prevent esophageal perforation and identify residual circular muscle fibers.

T-Cell Costimulation Protects Obesity-Induced Adipose Inflammation and Insulin Resistance

A key pathophysiologic role for activated T-cells in mediating adipose inflammation and insulin resistance (IR) has been recently postulated. However, mechanisms underlying their activation are poorly understood. In this study, we demonstrated a previously unrecognized homeostatic role for the costimulatory B7 molecules (CD80 and CD86) in preventing adipose inflammation. Instead of promoting inflammation, which was found in many other disease conditions, B7 costimulation reduced adipose inflammation by maintaining regulatory T-cell (Treg) numbers in adipose tissue. In both humans and mice, expression of CD80 and CD86 was negatively correlated with the degree of IR and adipose tissue macrophage infiltration. Decreased B7 expression in obesity appeared to directly impair Treg proliferation and function that lead to excessive proinflammatory macrophages and the development of IR. CD80/CD86 double knockout (B7 KO) mice had enhanced adipose macrophage inflammation and IR under both high-fat and normal diet conditions, accompanied by reduced Treg development and proliferation. Adoptive transfer of Tregs reversed IR and adipose inflammation in B7 KO mice. Our results suggest an essential role for B7 in maintaining Tregs and adipose homeostasis and may have important implications for therapies that target costimulation in type 2 diabetes.

A review of 130 humans enrolled in transgastric NOTES protocols at a single institution.

BackgroundThe methodology of Natural Orifice Translumenal Endoscopic Surgery (NOTES) has been validated in both human and animal models. Herein is a discussion of our experience gained from the initial 130 patients enrolled in transgastric pre-NOTES and NOTES protocols at our institution.MethodsA retrospective review of our research database was performed for all patients enrolled in NOTES protocols. The infectious risk of a gastrotomy with and without a NOTES procedure was assessed in 100 patients. Eighty patients completed a true NOTES protocol looking at staging, access, and insufflation with select patients evaluating the potential for bacterial contamination of the abdominal compartment.ResultsA total of 130 patients have completed pre-NOTES and NOTES protocols at our institution. We observed no clinically significant contamination of the abdomen secondary to transgastric procedures in 100 patients. Diagnostic transgastric endoscopic peritoneoscopy (DTEP) was completed in 20 patients with pancreatic head masses and found to have a 95% concordance with laparoscopic exploration for assessment of peritoneal metastases. Blind endoscopic gastrotomy and DTEP were evaluated in 40 patients who underwent laparoscopic Roux-en-Y gastric bypass procedures (LSRYGB) and were found to be safe, reliable, and without a clinically significant risk of contamination. Endoscopic peritoneal insufflation was successfully established and correlated with standard laparoscopic insufflation in 20 patients.ConclusionsTransgastric NOTES is a safe alternative approach to accessing the peritoneal cavity in humans. The risk of bacterial contamination secondary to peroral and transgastric access is clinically insignificant. A device for the facile closure of the gastric defect is the sole factor limiting institution of this methodology as a standalone technique.

Heating and humidifying of carbon dioxide during pneumoperitoneum is not indicated: A prospective randomized trial

BackgroundCarbon dioxide (CO2) pneumoperitoneum usually is created by a compressed gas source. This exposes the patient to cool dry gas delivered at room temperature (21°C) with 0% relative humidity. Various delivery methods are available for humidifying and heating CO2 gas. This study was designed to determine the effects of heating and humidifying gas for the intraabdominal environment.MethodsFor this study, 44 patients undergoing laparoscopic Roux-en-Y gastric bypass were randomly assigned to one of four arms in a prospective, randomized, single-blinded fashion: raw CO2 (group 1), heated CO2 (group 2), humidified CO2 (group 3), and heated and humidified CO2 (group 4). A commercially available CO2 heater–humidifier was used. Core temperatures, intraabdominal humidity, perioperative data, and postoperative outcomes were monitored. Peritoneal biopsies were taken in each group at the beginning and end of the case. Biopsies were subjected staining protocols designed to identify structural damage and macrophage activity. Postoperative narcotic use, pain scale scores, recovery room time, and length of hospital stay were recorded. One-way analysis of variance (ANOVA) and the nonparametric Kruskal–Wallis test were used to compare the groups.ResultsDemographics, volume of CO2 used, intraabdominal humidity, bladder temperatures, lens fogging, and operative times were not significantly different between the groups. Core temperatures were stable, and intraabdominal humidity measurements approached 100% for all the patients over the entire procedure. Total narcotic dosage and pain scale scores were not statistically different. Recovery room times and length of hospital stay were similar in all the groups. Only one biopsy in the heated–humidified group showed an increase in macrophage activity.ConclusionsThe intraabdominal environment in terms of temperature and humidity was similar in all the groups. There was no significant difference in the intraoperative body temperatures or the postoperative variable measured. No histologic changes were identified. Heating or humidifying of CO2 is not justified for patients undergoing laparoscopic bariatric surgery.

New bioinformatics approach to analyze gene expressions and signaling pathways reveals unique purine gene dysregulation profiles that distinguish between CD and UC

Background: Expression of purine genes is modulated by inflammation or experimental colitis and altered expression leads to disrupted gut function. We studied purine gene dysregulation profiles in inflammatory bowel disease (IBD) and determined whether they can distinguish between Crohns disease (CD) and ulcerative colitis (UC) using Pathway Analysis and a new Comparative Analysis of Gene Expression and Selection (CAGES) method. Methods: Raw datasets for 22 purine genes and 36 probe‐sets from National Center for Biotechnology Information (NCBI) GEO (Gene Expression Omnibus) (http://www.ncbi.nlm.nih.gov/projects/geo/) were analyzed by National Cancer Institute (NCI) Biological Resources Branch (BRB) array tools for random‐variance of multiple/36 t‐tests in colonic mucosal biopsies or peripheral blood mononuclear cells (PBMCs) of CD, UC or control subjects. Dysregulation occurs in 59% of purine genes in IBD including ADORA3, CD73, ADORA2A, ADORA2B, ADAR, AMPD2, AMPD3, DPP4, P2RY5, P2RY6, P2RY13, P2RY14, and P2RX5. Results: In CD biopsies, expression of ADORA3, AMPD3, P2RY13, and P2RY5 were negatively correlated with acute inflammatory score, Crohns Disease Activity Index (CDAI) or disease chronicity; P2RY14 was positively correlated in UC. In mucosal biopsies or PBMCs, CD and UC were distinguished by unique patterns of dysregulation (up‐ or downregulation) in purine genes. Purine gene dysregulation differs between PBMCs and biopsies and possibly between sexes for each disease. Ingenuity Pathway Analysis (IPA) revealed significant associations between alterations in the expression of CD73 (upregulation) or ADORA3 (downregulation) and inflammatory or purine genes (≤10% of 57 genes) as well as G‐protein coupled receptors, cAMP‐dependent, and inflammatory pathways; IPA distinguishes CD from UC. Conclusion: CAGES and Pathway Analysis provided novel evidence that UC and CD have distinct purine gene dysregulation signatures in association with inflammation, cAMP, or other signaling pathways. Disease‐specific purine gene signature profiles and pathway associations may be of therapeutic, diagnostic, and functional relevance.