CAR-T cells and CAR-Tregs targeting conventional type-1 dendritic cell suppress experimental autoimmune encephalomyelitis.

Conventional type 1 dendritic cells (DC1) contribute to the development of pathogenic T helper type 1 (Th1) cells in part via the production of the proinflammatory cytokine interleukin-12. Thus, depletion of DC1 has the potential to dampen autoimmune responses. Here, we developed X-C motif chemokine receptor 1 (XCR1)-specific chimeric antigen receptor (CAR)-T cells and CAR-Tregs that specifically targeted DC1. XCR1 CAR-T cells were successfully generated as CD4+ and CD8+ T cells, expressed XCR1 CAR efficiently, and induced XCR1-dependent activation, cytokine production and proliferation. XCR1 CAR-T cells selectively depleted DC1 when transferred into RAG2-/- mice with a compensatory increase in conventional type 2 DC (DC2) and plasmacytoid DC (pDC). XCR1 CAR-T cell-mediated depletion of DC1 modestly suppressed the onset of Th1-driven experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Diphtheria toxin-mediated DC1 depletion in XCR1-diphtheria toxin receptor mice also suppressed EAE, suggesting that DC1 depletion was responsible for EAE suppression. XCR1 CAR-Tregs were successfully generated and suppressed effector T cells in the presence of XCR1+ cells. Therapeutic treatment with XCR1 CAR-Tregs suppressed Th1-driven EAE. Therefore, we conclude that depletion of DC1 with XCR1 CAR-T cells or immune suppression with XCR1 CAR-Tregs can modestly suppress Th1-driven EAE.

Attenuated IL-2 muteins leverage the TCR signal to enhance regulatory T cell homeostasis and response in vivo.

Interleukin-2 (IL-2), along with T-cell receptor (TCR) signaling, are required to control regulatory T cell (Treg) homeostasis and function in vivo. Due to the heightened sensitivity to IL-2, Tregs retain the ability to respond to low-dose or attenuated forms of IL-2, as currently being developed for clinical use to treat inflammatory diseases. While attenuated IL-2 increases Treg selectivity, the question remains as to whether a weakened IL-2 signal sufficiently enhances Treg suppressive function(s) toward disease modification. To understand this question, we characterized the in vivo activity and transcriptomic profiles of two different attenuated IL-2 muteins in comparison with wildtype (WT) IL-2. Our study showed that, in addition to favoring Tregs, the attenuated muteins induced disproportionately robust effects on Treg activation and conversion to effector Treg (eTreg) phenotype. Our data furthermore suggested that Tregs activated by attenuated IL-2 muteins showed reduced dependence on TCR signal, at least in part due to the enhanced ability of IL-2 muteins to amplify the TCR signal in vivo. These results point to a new paradigm wherein IL-2 influences Tregs' sensitivity to antigenic signal, and that the combination effect may be leveraged for therapeutic use of attenuated IL-2 muteins.

Titration of sevoflurane anesthesia to optimize the time to regain airway reflexes in patients undergoing elective surgery: A randomized clinical trial comparing desflurane and sevoflurane anesthesia.

BACKGROUND: Desflurane has adverse environmental effects, but has clinical advantages to speed emergence and return of protective airway reflexes compared with sevoflurane. We hypothesized that weaning of the inspired sevoflurane during the final 15 minutes of surgery would eliminate differences in airway reflex recovery between these agents. METHODS: After obtaining IRB approval and informed consent, 40 patients undergoing elective surgery (≥1-hour) randomly received desflurane or sevoflurane. Patients swallowed 20 mL of water without drooling or coughing, and then received sedation and PONV pre-medication. Anesthesia was induced using propofol and fentanyl and maintained with desflurane or sevoflurane through a laryngeal mask airway maintaining a bispectral index of 45-50 and 50-60 during the final 15 minutes before surgery end. Cardiorespiratory variables and age-adjusted minimal alveolar concentration were recorded. The duration between anesthetic discontinuation and first appropriate response to command was measured; the laryngeal mask airway was removed. Two minutes after responding to command, patients were positioned semi-upright and attempted to swallow water. If successful swallowing was not achieved, the test was repeated every 4 minutes after each failure until successful swallowing was achieved. RESULTS: Average anesthetic concentration and bispectral index was similar in patients receiving desflurane vs sevoflurane. Response times after discontinuation of anesthetics were similar. There were no differences in the recovery of swallowing ability between desflurane and sevoflurane groups. CONCLUSION: Weaning of sevoflurane during the final 15 minutes of surgery eliminates clinical advantages of the more rapid return of airway reflexes with desflurane.

Progressive regression of left ventricular hypertrophy two years after bariatric surgery.

BACKGROUND: Obesity is a systemic disorder associated with an increase in left ventricular mass and premature death and disability from cardiovascular disease. Although bariatric surgery reverses many of the hormonal and hemodynamic derangements, the long-term collective effects on body composition and left ventricular mass have not been considered before. We hypothesized that the decrease in fat mass and lean mass after weight loss surgery is associated with a decrease in left ventricular mass. METHODS: Fifteen severely obese women (mean body mass index [BMI]: 46.7+/-1.7 kg/m(2)) with medically controlled hypertension underwent bariatric surgery. Left ventricular mass and plasma markers of systemic metabolism, together with body mass index (BMI), waist and hip circumferences, body composition (fat mass and lean mass), and resting energy expenditure were measured at 0, 3, 9, 12, and 24 months. RESULTS: Left ventricular mass continued to decrease linearly over the entire period of observation, while rates of weight loss, loss of lean mass, loss of fat mass, and resting energy expenditure all plateaued at 9 [corrected] months (P <.001 for all). Parameters of systemic metabolism normalized by 9 months, and showed no further change at 24 months after surgery. CONCLUSIONS: Even though parameters of obesity, including BMI and body composition, plateau, the benefits of bariatric surgery on systemic metabolism and left ventricular mass are sustained. We propose that the progressive decrease of left ventricular mass after weight loss surgery is regulated by neurohumoral factors, and may contribute to improved long-term survival.

Comparison of those who succeed in losing significant excessive weight after bariatric surgery and those who fail.

BACKGROUND: Gastric bypass and adjustable gastric banding currently are the most commonly performed weight loss surgeries. The results are encouraging for most patients, but some patients have a better experience than others. This report aims to define differences between those who succeeded and those that failed to lose significant excessive weight after bariatric surgery. METHODS: The authors retrospectively reviewed their database over the past 4 years. They studied 484 bariatric patients who had 1 year of follow-up evaluation. Success was defined as more than 50% excess weight loss (EWL) and failure as less than 30% EWL. Student's t-tests were performed between the groups of bypass patients, band patients, men, women, whites, and minorities. RESULTS: An overall success rate of 58% and a failure rate of 15% were observed. The successful group was significantly younger. The starting body mass index (BMI) was significantly lower for the successful band patients. The starting excess weight was significantly less in both the successful band and bypass groups, as was the starting weight. The successful whites were significantly younger, and the starting BMI was significantly lower in the successful minority group. The unsuccessful bypass patients and whites were significantly taller than the successful group. Gender was not a significant variable in success or failure regardless of procedure. CONCLUSION: Without consideration for the procedure performed, the patients who successfully lost weight were younger. The unsuccessful band patients had a higher starting BMI, whereas the successful band and bypass patients had lower average starting and excess weights. The successful bypass patients were significantly shorter. Among whites, the successful patients were significantly younger and shorter. The successful minorities had a lower starting BMI. These variables give further insight into the complexity of successful excess weight loss.

Failure of adjustable gastric banding: starting BMI of 46 kg/m2 is a fulcrum of success and failure.

BACKGROUND: To determine the body mass index (BMI) located at the fulcrum of success and failure in a prospective study conducted at the University of Texas Health Science Center at Houston. On average, our patients whose percentage of excess weight loss (%EWL) was >50% at 1 year had a significantly lower BMI than those with <30% EWL. METHODS: We prospectively collected the weight loss data for 430 patients who had had an adjustable gastric band placed. We stratified the %EWL within 1 year for patients with a BMI of 30-59 kg/m2. A line was generated for the %EWL over time for BMI groups of 30-39, 40-49, and 50-59 kg/m(2) and compared with the average %EWL over time. The y-intercepts of the resulting four lines were graphed against the average BMI for each group. RESULTS: The generated y-intercept line had an R2 of .9237. Using the equation of this line and the known y-intercept for the average, we solved for x, resulting in a BMI of 46 kg/m2. Patients with a BMI <46 kg/m2 had a 50% EWL at 1 year, and those with a BMI >46 kg/m2 had only a 33% EWL at 1 year. The %EWL between the groups was significantly different at all measured intervals (P <.0001). CONCLUSION: A BMI of 46 kg/m2 identifies those at high risk of failure to lose a significant percentage of excess weight after adjustable gastric banding and who require closer follow-up. Furthermore, patients who have a BMI >46 kg/m2 should be advised that their weight loss might be suboptimal at 1 year.

Explanations for unsuccessful weight loss among bariatric surgery candidates.

BACKGROUND: Our objective was to analyze subjective explanations for unsuccessful weight loss among bariatric surgery candidates. METHODS: This was a retrospective analysis of 909 bariatric surgery candidates (78.2% female, average body mass index [BMI] 47.3) at a university center from 2001 to April 2007 who answered an open-ended question about why they were unable to lose weight. We generated a coding scheme for answers to the question and established inter-rater reliability of the coding process. Associations with demographic parameters and initial BMI were tested. RESULTS: The most common categories of answers were nonspecific explanations related to diet (25.3%), physical activity (21.0%), or motivation (19.7%), followed by diet-related motivation (12.7%) and medical conditions or medications affecting physical activity (12.7%). Categories related to time, financial cost, social support, physical environment, and knowledge occurred in less than 4% each. Men were more likely than women to cite a medical condition or medication affecting physical activity (19.2% vs 10.8%, P = 0.002, odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.28-2.99) but less likely to cite diet-related motivation (7.1% vs 14.2%, P = 0.008, OR = 0.46, 95% CI = 0.26-0.82). CONCLUSIONS: Our findings suggest that addressing diet, physical activity, and motivation in a comprehensive approach would meet the stated needs of obese patients. Raising patient awareness of under-recognized barriers to weight loss, such as the physical environment and lack of social support, should also be considered. Lastly, anticipating gender-specific attributions may facilitate tailoring of interventions.

Dramatic reversal of derangements in muscle metabolism and left ventricular function after bariatric surgery.

OBJECTIVE: The study objective was to define muscle metabolic and cardiovascular changes after surgical intervention in clinically severe obese patients. METHODS: Obesity is a state of metabolic dysregulation that can lead to maladaptive changes in heart and skeletal muscle, including insulin resistance and heart failure. In a prospective longitudinal study, 43 consecutive patients underwent metabolic profiling, skeletal muscle biopsies, and resting echocardiograms at baseline and 3 and 9 months after bariatric surgery. RESULTS: Body mass index decreased (mean changes, 95% confidence interval [CI]): 7.7 kg/m(2) (95% CI, 6.70-8.89) at 3 months and 5.6 kg/m(2) (95% CI, 4.45-6.80; P<.0001) at 9 months after surgery, with restoration of insulin sensitivity and decreases in plasma leptin at the same time points. Concurrent with these changes were dramatic decreases in skeletal muscle transcript levels of stearoyl coenzyme-A desaturase and pyruvate dehydrogenase kinase-4 at 3 and 9 months (P<.0001, for both) and a significant decrease in peroxisome proliferation activated receptor-alpha-regulated genes at 9 months. Left ventricular relaxation impairment, assessed by tissue Doppler imaging, normalized 9 months after surgery. CONCLUSION: Weight loss results in the reversal of systemic and muscle metabolic derangements and is accompanied by a normalization of left ventricular diastolic function.

Lowering gastrointestinal leak rates: a comparative analysis of robotic and laparoscopic gastric bypass.

Robotic-assisted surgery has been described for many general surgery procedures, including gastric bypass. This is a comparative study looking at the short-term outcomes and technical differences between laparoscopic Roux-en-Y gastric bypass (LRNY) and robotic-assisted Roux-en-Y gastric bypass (RARNY). Our database was reviewed for all Roux-en-Y gastric bypass procedures performed over the last 5 years. Operative times, length of stay, and all complications listed for the 90 days postoperatively were recorded and statistically analyzed. A total of 356 LRNY and 249 RARNY were performed. The average body mass index (BMI), age, and sex were similar between groups. On average, the RARNY took 17 min longer than the LRNY, this difference being significant (p < 0.01). Average length of stay for the two groups was similar (~3 days). There were a total of 51 complications in the standard laparoscopic group (14%), of which 14 (3.9%) were major complications. In the robotic group, there were 35 (14%) complications, of which 9 (3.6%) were major complications. The only significant difference in complication rate was for anastomotic leak at the gastrojejunostomy: there were no leaks in the robotic series, and six (1.7%) in the standard laparoscopic series (p = 0.04). Length of stay and overall complication rates were similar for RARNY and LRNY. There was no mortality in either group, and the complication rate was lower than literature standards. While the RARNY took longer, there was a significantly lower gastrointestinal leak rate in this group.

Preoperative upper endoscopy is useful before revisional bariatric surgery.

BACKGROUND AND OBJECTIVES: We hypothesized that patients who have previously had bariatric surgery and are undergoing revision to laparoscopic Roux-en-Y gastric bypass would have abnormal findings detected by upper endoscopy that could potentially influence patient management. The procedures that are being revised include vertical banded gastroplasty, laparoscopic adjustable gastric bands, nonadjustable gastric bands and previous Roux-en-Y gastric bypass (open and laparoscopic). METHODS: We conducted a retrospective chart review of patients who previously had undergone vertical banded gastroplasty or nonadjustable gastric banding. We preoperatively performed an upper endoscopy on all patients. The endoscopy reports were reviewed and the findings entered into a database. RESULTS: Eighty-five percent of 46 patients undergoing revisional bariatric surgery had an abnormal upper endoscopy. Eleven percent had a gastrogastric fistula. Gastritis and esophagitis were noted in 65% and 37%, respectively. Eleven percent of patients had band erosion, 2 from a nonadjustable band, and 5 from vertical banded gastroplasties. Based on our findings, 65% of our patients required medical treatment. CONCLUSIONS: Preoperative upper endoscopy provides valuable information before revisional laparoscopic bariatric surgery. In addition to identifying patients who need preoperative medications, the preoperative upper endoscopy also provided valuable information regarding pouch size and anatomy. Preoperative upper endoscopy should be performed by the operating surgeon on every patient undergoing revisional bariatric surgery.

Robotic assistance provides excellent outcomes during the learning curve for laparoscopic Roux-en-Y gastric bypass: results from 100 robotic-assisted gastric bypasses.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) has a reported learning curve of 100 cases. Robotic-assisted surgery decreases the learning curve in complex laparoscopic surgeries. We hypothesize that robotic-assisted, hand-sewn gastrojejunostomy during a LRYGB will improve results during the initial 100 cases when compared with the literature. METHODS: Our first 100 robotic-assisted gastrojejunostomies performed during LRYGB were reviewed from a prospective database. Patient demographics, operative times, length of stay, reoperations, anastomotic leak, pulmonary embolus, and death were all evaluated. RESULTS: The mean age and body mass index were 42 and 50, respectively. Operative times ranged from 148 minutes to 437 minutes (mean = 254). There were no leaks or deaths. Four patients had complications, including reoperation (1), incisional hernia (1), pulmonary embolus (1), and recurrent umbilical hernia (1). CONCLUSIONS: Robotic-assisted LRYGB is feasible and safe, as evidenced by the excellent outcomes from this series during the initial learning curve for LRYGB.

Preservation of an aberrant left hepatic artery during laparoscopic nissen fundoplication.

OBJECTIVE: Laparoscopic Nissen fundoplication is performed in neonates and children for significant gastroesophageal reflux. An aberrant left hepatic artery encountered during laparoscopic Nissen fundoplication makes dissection around the esophageal hiatus more difficult if the artery is not transected. Although some suggest division of the aberrant left hepatic artery, this is associated with risk of significant hepatic injury from ischemia. We routinely preserve the aberrant left hepatic artery and sought to determine (1) the incidence of aberrant left hepatic artery and (2) the results following preservation of the aberrant left hepatic artery. METHODS: Between January 2000 and October 2002, 195 laparoscopic Nissen fundoplications were performed. We documented intraoperative findings of each procedure, and reviewed postoperative radiographic studies and clinic visits. RESULTS: In 30 patients (15%), an aberrant left hepatic artery was identified. All dissections were performed laparoscopically with the Nissen fundoplication positioned cephalad to the aberrant left hepatic artery. Postoperatively, 2 patients (6%) have had evidence of wrap failure. The remainder of the patients has had normal radiographic studies or no clinical evidence of reflux during clinic visits. CONCLUSION: During laparoscopic Nissen fundoplication in neonates and children, an aberrant left hepatic artery may be encountered in approximately 15% of patients. When an aberrant left hepatic artery is identified, it should be preserved to avoid the potential risk of hepatic ischemic injury.

Laparoscopic guidance or revision of ventriculoperitoneal shunts in children.

BACKGROUND: Ventriculoperitoneal shunt is the preferred treatment for hydrocephalus. Known complications include infection, obstruction, and disconnection with the fractured fragment migrating in the peritoneal cavity. We report 17 cases of laparoscopic evaluation and revision of ventriculoperitoneal shunts in children. METHODS: From January 2000 through October 2002, we retrospectively reviewed our experience with laparoscopy and ventriculoperitoneal shunts. RESULTS: Laparoscopy was performed in 17 children with a malfunctioning shunt, presumed shunt dislodgment or disconnection, reinsertion of a shunt after externalization, and primary shunt placement. Six patients (35%) were converted to an open laparotomy due to dense adhesions. Eleven patients (65%) underwent successful laparoscopic-assisted ventriculoperitoneal shunt placement: 5/11 (45%) had lysis of adhesions or pseudocyst marsupialization with repositioning of a functional shunt, or both; 3/11 (27%) had successful retrieval of a disconnected catheter with reinsertion of a new catheter; 2/11 (18%) had laparoscopic confirmation of satisfactory placement and function, requiring no revision; 1/11 (9%) had an initial shunt placed with laparoscopic guidance due to the obesity. Operative time for the laparoscopic procedure ranged from 30 minutes to 60 minutes. All laparoscopic procedures used 1-mm or two 5-mm ports. Perioperatively, no adverse neurological sequelae occurred due to the pneumoperitoneum. CONCLUSIONS: Laparoscopic guidance or revision of ventriculoperitoneal shunts permits (1) direct visualization of catheter insertion within the peritoneal cavity, (2) satisfactory positioning, (3) lysis of adhesions or marsupialization with catheter repositioning, or both, and (4) retrieval of fractured catheters.

Early experience with laparoscopic pyloromyotomy in a teaching institution.

OBJECTIVE: Hypertrophic pyloric stenosis is a common pediatric surgical condition. A Ramstedt pyloromyotomy is performed either via laparotomy or laparoscopy. We report our first 25 cases of laparoscopic pyloromyotomy at an academic children's hospital. METHODS: From January 2002 through February 2003, we retrospectively reviewed our first 25 laparoscopic pyloromyotomies. All patients had documented hypertrophic pyloric stenosis by ultrasound criteria. Three incisions were made, one 5-mm umbilical port, one 3-mm right upper quadrant port, and a third left upper quadrant working stab incision. A 4-mm, 30 degrees scope was used in all cases. A longitudinal pyloromyotomy was performed using an arthrotomy scalpel. The pylorus was further separated with a laparoscopic Benson spreader. At the completion of the pyloromyotomy, the stomach was insufflated with air to identify any mucosal injury. RESULTS: Age range was 2.3 weeks to 8.4 weeks. Operating time has decreased from 70 minutes to 15 minutes. Two conversions to an open procedure were necessary, both during the first 10 cases. No mucosal perforations or incomplete pyloromyotomies have occurred. Feeds were started within 4 hours and advanced to goal. Time to discharge ranged from 12 hours to 30 hours. One patient developed umbilical cellulitis that was successfully treated with antibiotics. CONCLUSIONS: Laparoscopic pyloromyotomy is a safe, effective procedure for hypertrophic pyloric stenosis in a resident teaching environment. Laparoscopy permits excellent visualization, has comparable postoperative recovery, and superior cosmesis.

Laparoscopic-assisted percutaneous endoscopic gastrostomy in children and adolescents.

OBJECTIVE: Pediatric gastric access for long-term enteral feeding may be performed via a laparotomy, laparoscopy, or a percutaneous approach. In children and adolescents, laparoscopic-assisted gastrostomy may be difficult due to a thick abdominal wall. Therefore, if the abdominal wall is estimated to be >2 cm on physical examination, or in children in whom a percutaneous endoscopic gastrostomy was unsuccessfully attempted by a gastroenterologist, we routinely perform a laparoscopic-assisted percutaneous endoscopic gastrostomy. METHODS: From January 1998 through February 2003, we retrospectively reviewed 15 cases of a laparoscopic-assisted percutaneous endoscopic gastrostomy. Instruments used to perform this technique are a percutaneous endoscopic gastrostomy kit, an Olympus flexible endoscope, and one 5-mm STEP port placed through an infraumbilical incision for a 5-mm, 30-degree scope. RESULTS: Age range was 2 years to 20 years (mean, 10). Operative time ranged from 20 minutes to 45 minutes. When a concurrent laparoscopic Nissen fundoplication was performed (n = 6), the percutaneous endoscopic gastrostomy was placed after completion of the Nissen fundoplication. No intraoperative complications occurred, and all tubes were successfully placed. Feeds were instituted the following day and advanced to goal. To date, no postoperative complications have occurred, and revision has not been necessary. CONCLUSIONS: Laparoscopic-assisted percutaneous endoscopic gastrostomy in children and adolescents is safe and effective. Utilizing laparoscopy permits evaluation of the peritoneum and lysis of adhesions, if necessary. Moreover, laparoscopy provides excellent exposure for accurate placement of the PEG, while avoiding injury to other organs.