Showing papers by "Tim Jackson published in 2019"

Gut-associated IgA+ immune cells regulate obesity-related insulin resistance

Abstract: The intestinal immune system is emerging as an important contributor to obesity-related insulin resistance, but the role of intestinal B cells in this context is unclear. Here, we show that high fat diet (HFD) feeding alters intestinal IgA+ immune cells and that IgA is a critical immune regulator of glucose homeostasis. Obese mice have fewer IgA+ immune cells and less secretory IgA and IgA-promoting immune mediators. HFD-fed IgA-deficient mice have dysfunctional glucose metabolism, a phenotype that can be recapitulated by adoptive transfer of intestinal-associated pan-B cells. Mechanistically, IgA is a crucial link that controls intestinal and adipose tissue inflammation, intestinal permeability, microbial encroachment and the composition of the intestinal microbiome during HFD. Current glucose-lowering therapies, including metformin, affect intestinal-related IgA+ B cell populations in mice, while bariatric surgery regimen alters the level of fecal secretory IgA in humans. These findings identify intestinal IgA+ immune cells as mucosal mediators of whole-body glucose regulation in diet-induced metabolic disease. The effect of diet-induced obesity on intestinal B cell populations is not well understood despite emerging evidence of a critical role for the intestinal immune system in contributing to insulin resistance. Here, the authors show important functions of IgA in regulating metabolic disease and for intestinal immunity in modulating systemic glucose metabolism.

High-Flow Nasal Oxygen Improves Safe Apnea Time in Morbidly Obese Patients Undergoing General Anesthesia: A Randomized Controlled Trial.

Abstract: BACKGROUND:Morbidly obese patients undergoing general anesthesia are at risk of hypoxemia during anesthesia induction. High-flow nasal oxygenation use during anesthesia induction prolongs safe apnea time in nonobese surgical patients. The primary objective of our study was to compare safe apnea time

Unraveling the claims for (and against) green growth.

Abstract: Can the global economy grow indefinitely, decoupled from Earth's limitations? American economist Kenneth Boulding famously quipped, “Anyone who believes that exponential growth can go on forever in a finite world is either a madman or an economist” (1). He was giving evidence to the U.S. Congress in 1973, in the wake of the Club of Rome's first, enormously influential and provocative report, The Limits to Growth (2). The remark has survived to this day as a somewhat satirical comment on the economics profession, but it also has a certain internal logic and provides a useful starting point for thinking about the “decoupling wars” that tend to be fought around the compatibility between economic growth and environmental limits (3).

Hypoalbuminaemia and Postoperative Outcomes in Inflammatory Bowel Disease: the NSQIP Surgical Cohort

Abstract: BACKGROUND The inflammatory bowel diseases [IBD], including Crohn's disease [CD] and ulcerative colitis [UC], frequently lead to bowel surgery. Hypoalbuminaemia has been shown to be a prognostic factor for outcomes following surgery for other indications, and we sought to determine its role in predicting IBD-related postoperative outcomes. METHODS We included patients who underwent IBD-related major abdominal surgery in the American College of Surgeons' National Surgical Quality Improvement Program [ACS-NSQIP] between 2005 and 2012. We assessed the impact of indicators of protein-energy malnutrition [PEM] including hypoalbuminaemia, weight loss, and body mass index on postoperative outcomes. RESULTS We identified 10 913 IBD patients [6082 Crohn's disease and 4831 ulcerative colitis] who underwent bowel surgery. The prevalence of modest and severe hypoalbuminaemia was 17% and 24%, respectively; 30-day mortality was higher in Crohn's patients with modest and severe hypoalbuminaemia compared with those with normal albumin levels preoperatively [0.7% vs 0.2%, p <0.05; 2.4% vs 0.2%, p <0.01]. The same was true for patients with UC with modest and severe hypoalbuminaemia [0.9% vs 0.1%, p <0.01; 5.6% vs 0.1%, p <0.01]. Overall infectious complications were more common in the presence of severe hypoalbuminaemia for CD [20% vs 13%, p <0.01]. and UC [28% vs 15%, p <0.01] patients. Last, there were higher rates of extra-intestinal, non-septic complications in both CD and UC patients with hypoalbuminaemia compared with those with normal albumin levels. CONCLUSIONS This study suggests that moderate-severe hypoalbuminaemia is associated with worse IBD-related postoperative outcomes and may have a role in preoperative risk stratification.

Flow Activities as a Route to Living Well With Less

Abstract: Research suggests that the excessive focus on the acquisition of material goods promoted by our consumer society may be detrimental to well-being Current Western lifestyles, which promote unsustai

Thirty-Day Outcomes Following Surgical Decompression of Thoracic Outlet Syndrome.

Abstract: Background: Surgical thoracic outlet syndrome (TOS) management involves decompression of the neurovascular structures by releasing the anterior and/or middle scalene muscles, resection of the first...

Developing minimally invasive procedure quality metrics: one step at a time

Abstract: Despite extensive first-hand surgical experience, rank and file members of surgical societies are generally not trained in and have not therefore been included in surgical quality measure development. The purpose of this exercise was to determine if a structured quality metric design tool could bridge this gap, facilitating rapid development of focused quality metrics by minimally invasive surgeon attendees of the April 2018 SAGES Annual Meeting. Expert minimally invasive surgeons attended a 90-min workshop with didactic and interactive quality metric design sessions during the Annual Meeting. The interactive portion was formed around a novel structured quality measure development tool that graded presenting symptoms, short-term complications, and long-term disutility of care. For first-time symptomatic inguinal hernia repair, first-time small to moderate size ventral hernia repair, and elective laparoscopic cholecystectomy, each workgroup was able to develop one quality, one short-term complication, and one long-term disutility metric. A structured quality metric design tool facilitates application of knowledge through rapid development of multifaceted, patient-centric outcomes measures by expert minimally invasive surgeons, otherwise not formally trained in metric development. The exercise also highlighted the need to rigorously define denominator populations and to guard against metric-driven undertreatment.

Emergency laparoscopic and open repair of incarcerated ventral hernias: a multi-institutional comparative analysis with coarsened exact matching

Abstract: The safety of emergent laparoscopic repair of incarcerated ventral hernias is not well established. The objective of this study was to determine if emergent laparoscopic repair of incarcerated ventral hernias is comparable to open repair with respect to short-term clinical outcomes. Patients undergoing emergency repair of an incarcerated ventral hernia with associated obstruction and/or gangrene were identified using the ACS-NSQIP 2012–2016 dataset. One-to-one coarsened exact matching (CEM) was conducted between patients undergoing laparoscopic and open repair. Matched cohorts were compared with respect to morbidity, mortality, readmission, reoperation, missed enterotomies, and length of stay. Missed enterotomy was defined as any re-operative procedure within 30 days that required resection of large or small bowel segments, based on CPT codes. Multivariate analysis was conducted to determine adjusted predictors of morbidity. A total of 1642 patients were identified after CEM. Laparoscopic compared to open repair was associated with a lower rate of 30-day wound-morbidity (OR 0.35, 95% CI 0.22–0.57, p < 0.001). Laparoscopic repair was not associated with lower 30-day non-wound morbidity (OR 0.73, 95% CI 0.51–1.06, p = 0.094). Laparoscopic repair was associated with shorter LOS (3.6 days vs. 4.3 days, p = 0.014). A higher rate of missed enterotomies was observed in the laparoscopic cohort (0.7% vs. 0.0%, p = 0.031). There were no group differences with respect to 30-day readmission, reoperation, or mortality. Emergency laparoscopic repair of incarcerated ventral hernias is associated with lower rates of wound-morbidity and shorter hospital stays compared to open repair. However, laparoscopic repair is associated with a higher rate of missed enterotomies; a rate which is low and comparable to elective non-incarcerated ventral hernia repairs.

Prospective Study of Attachment as a Predictor of Binge Eating, Emotional Eating and Weight Loss Two Years after Bariatric Surgery

Abstract: Bariatric surgery remains the most effective treatment for severe obesity, though post-surgical outcomes are variable with respect to long-term weight loss and eating-related psychopathology. Attachment style is an important variable affecting eating psychopathology among individuals with obesity. To date, studies examining eating psychopathology and attachment style in bariatric surgery populations have been limited to pre-surgery samples and cross-sectional study design. The current prospective study sought to determine whether attachment insecurity is associated with binge eating, emotional eating, and weight loss outcomes at 2-years post-surgery. Patients (n = 108) completed questionnaires on attachment style (ECR-16), binge eating (BES), emotional eating (EES), depression (PHQ-9), and anxiety (GAD-7). Multivariate linear regression analyses were conducted to examine the association between attachment insecurity and 2-years post-surgery disordered eating and percent total weight loss. Female gender was found to be a significant predictor of binge eating (p = 0.007) and emotional eating (p = 0.023) at 2-years post-surgery. Avoidant attachment (p = 0.009) was also found to be a significant predictor of binge eating at 2-years post-surgery. To our knowledge, this study is the first to explore attachment style as a predictor of long-term post-operative eating pathology and weight outcomes in bariatric surgery patients.

Evaluation of the Genetic Association Between Adult Obesity and Neuropsychiatric Disease.

Abstract: Extreme obesity (EO) (BMI >50 kg/m2) is frequently associated with neuropsychiatric disease (NPD). As both EO and NPD are heritable central nervous system disorders, we assessed the prevalence of protein-truncating variants (PTVs) and copy number variants (CNVs) in genes/regions previously implicated in NPD in adults with EO (n = 149) referred for weight loss/bariatric surgery. We also assessed the prevalence of CNVs in patients referred to University College London Hospital (UCLH) with EO (n = 218) and obesity (O) (BMI 35–50 kg/m2; n = 374) and a Swedish cohort of participants from the community with predominantly O (n = 161). The prevalence of variants was compared with control subjects in the Exome Aggregation Consortium/Genome Aggregation Database. In the discovery cohort (high NPD prevalence: 77%), the cumulative PTV/CNV allele frequency (AF) was 7.7% vs. 2.6% in control subjects (odds ratio [OR] 3.1 [95% CI 2–4.1]; P

Adaptation of the fundamentals of laparoscopic surgery box for endoscopic simulation: performance evaluation of the first 100 participants

Abstract: The paucity of readily accessible, cost-effective models for the simulation, practice, and evaluation of endoscopic skills present an ongoing barrier for resident training. We have previously described a system for conversion of the Fundamentals of Laparoscopic Surgery box (FLS) for flexible endoscopic simulation. Six endoscopic tasks focusing on scope manipulation, and other clinically relevant endoscopic skills are performed within a 5-min time limit per task. This study describes our experience and validation results with the first 100 participants. A total of 100 participants were evaluated on the simulator. Thirty individuals were classified as experts (having done over 200 endoscopic procedures), and 70 were classified as trainees (39 individuals reported having no prior endoscopy experience). Of the 100 participants, 55 individuals were retested on the simulator within a period of 4 months. These 55 individuals were also evaluated using the “Global Assessment of Gastrointestinal Endoscopic Skills” (GAGES). T-tests and Pearson correlations were used where appropriate, values less than 0.05 were considered significant. Experts completed all six tasks significantly faster than trainees. For the 55 participants who were retested on the simulator, all tasks demonstrated evidence of test–retest reliability for both experts and trainees who did not practice in between tests. Moderate correlations between lower completion times and higher GAGES scores were observed for all tasks except the clipping task. The results from the first 100 participants provide evidence for the simulator’s validity. Based on task completion times, we found that experts perform significantly better than trainees. Additionally, preliminary data demonstrate evidence of test–retest reliability, as well as GAGES score correlation. Additional studies to determine and validate a scoring system for this simulator are ongoing.

The return of investment of hospital-based surgical quality improvement programs in reducing surgical site infection at a Canadian tertiary-care hospital.

Abstract: Objective We performed a return-on-investment analysis comparing the investment in surgical site infection (SSI) prevention programs in a hospital setting to the savings from averted SSI cases. Design A retrospective case costing study using aggregated patient data to determine the incidence and costs of SSI infection in surgical departments over time. We calculated return on investment to the hospital and conducted several sensitivity and scenario analyses. Setting Data were compiled for the Ottawa Hospital (TOH), a Canadian tertiary-care teaching institution.PatientsWe used aggregated records for all hospital patients who underwent surgical procedures between April 2010 and January 2015.InterventionWe estimated the potential cost savings of the hospital's surgical quality improvement program, namely the Surgeons National Surgical Quality Improvement Program (NSQIP) and the Comprehensive Unit-based Safety Program (CUSP). Results From 2010 to 2016, TOH invested C$826,882 (US$624,384) in surgical quality improvement programs targeting SSI incidence and accrued C$1,885,110 (US$1,423,460) in cumulative savings from averted SSI cases, generating a return of $2.28 (US$3.02) per dollar invested (95% confidence interval [CI], -0.67 to 7.37). The study findings are sensitive to the estimated cost to the hospital per SSI case and the rate reduction attributable to the prevention program. Conclusions The NSQIP and CUSP have produced a positive return on investment at TOH; however, the result rests on several assumptions. This positive return on investment is expected to continue if the hospital can continue to reduce SSI incidence at least 0.25% annually without new investments. Findings from this study highlight the need for continuous program evaluation of the quality improvement initiatives.

Global Banking, Financial Spillovers, and Macroprudential Policy Coordination

Abstract: The gains from international macroprudential policy coordination are studied in a two-region, core-periphery macroeconomic model with imperfect financial integration and cross-border banking. Financial frictions occur at two levels: between firms and banks in each region, and between periphery banks and a global bank in the core region. Macroprudential regulation takes the form of a countercyclical tax on bank loans to domestic capital goods producers, which responds to real credit growth and is subject to a cost in terms of welfare. Numerical experiments, based on a parameterized version of the model, show that the welfare gains from macroprudential policy coordination are positive, albeit not large, for the world economy. In addition, these gains tend to increase with the degree of international financial integration. However, depending on the origin of financial shocks, they can also be highly asymmetric across regions.

Phenotypic and genetic analysis of an adult cohort with extreme obesity.

Abstract: Adult extreme obesity (EO) is a growing health concern. The prevalence of known obesity associated co-morbidities namely cardio-metabolic and neuro-psychiatric disease in EO is not fully established. The contribution of pathogenic genetic variants, previously implicated in early childhood onset obesity, to adult EO is also not established. We undertook phenotypic and genetic analysis of adult patients with extreme obesity (EO, BMI > 50). Specifically, we assessed the prevalence of eating disorders, cardio-metabolic, and neuro-psychiatric disease and the presence of pathogenic variants in known monogenic obesity genes. A total of 55 patients with EO from a single site bariatric surgery referral program were assessed for the presence of eating disorders, cardio-metabolic, and neuro-psychiatric disease. The 54 obese (O) patients with a BMI < 50 from the same program were identified for phenotypic comparison. The 45 EO patients underwent whole exome sequencing to identify deleterious variants in known monogenic obesity genes. (1) Presence of eating disorders, cardio-metabolic, and neuro-psychiatric disease in EO compared to O. (2) Onset of obesity in the EO group. (3) Presence of deleterious variants in genes previously implicated in monogenic obesity in the EO group. The EO group had higher prevalence of lifetime neuro-psychiatric disease (67.3% vs. 37%, p = 0.001) and sleep apnea (74.6% vs. 51.9%, p = 0.01) but lower prevalence of type 2 diabetes (30.1% vs. 50%, p = 0.045) compared to O. There were no significant differences in binge eating, dyslipidemia, hypertension, and cardiac disease. In the EO group, we found previously unreported singleton variants in NTRK2 (pS667W, bio-informatically predicted to be deleterious) and BDNF (pE23K). No previously confirmed loss of function variants in monogenic obesity genes were found. Adults with EO have significantly increased prevalence of neuro-psychiatric disease and a possibly lower burden of type 2 diabetes compared to less obese patients. Known monogenic causes of obesity were not highly prevalent in this cohort. Further studies are warranted to confirm these preliminary findings.

Living the Good Life on Instagram. An exploration of lay understandings of what it means to live well.

Abstract: While the consumerist approach to what living well can mean permeates traditional media, the extent to which it appears in people’s own depictions of the good life is unclear. As the unsustainability of the consumerist approach is increasingly evidenced, both in terms of environmental and social impacts, looking into which understandings of the good life resonate with people becomes essential. This article uses a sample of posts tagged #goodlife and variants originally collected in 2014-2015 on Instagram (a popular image sharing platform) to explore which understandings of the good life can be found on the platform. Using multimodal discourse analysis, it highlights two different user generated understandings of the good life: ‘working on future goals’ and ‘appreciating the present moment’. We argue that neither approach is directly or necessarily congruent with the traditional consumer good life. Yet their shared photographic codes with advertisements can contribute to their framing into the consumer good life. Additionally, the temporalities afforded by the platform and currently in place through social conventions may affect the type of narratives that are mediated. While the understandings derived from the analysis are not straightforward reflections of people’s beliefs about the meaning of the good life, they constitute conversations that at once inform, and are informed by, users’ beliefs about living well. The popularity of the platform makes these conversations crucial for anyone interested in desired lifestyles and their sustainability.

Physical activity and its association with psychosocial health following bariatric surgery.

Abstract: Physical activity (PA) helps sustain weight loss and may also provide psychological benefits in patients undergoing bariatric surgery. Using a set of questionnaires, we demonstrated that bariatric ...

Comparative Study of Early Health Care Use after Forearm Corrective Osteotomy.

Abstract: Background Bone reconstruction is frequently required for corrective osteotomy of the forearm long bones. Studies have evaluated long term outcomes but not the impact of these procedures on early postoperative complications and health care utilization. Questions/Purposes This study evaluated the early postoperative health care utilization following corrective osteotomy of the radius and/or ulna. Patients and Methods The American College of Surgeons' National Surgical Quality Improvement Program (NSQIP) was the primary data source to perform a comparative statistical analysis of the bone autograft and nonautograft (allograft, graft substitute, or no graft) procedures. We performed a review of the NSQIP database (2005-2013) to evaluate patients who underwent a corrective osteotomy of the radius and/or ulna. Results There were 362 cases; autograft ( n = 117) and nonautograft ( n = 245). There were no significant differences with demographics or comorbidities. The majority of cases were outpatient surgeries and there were no significant differences in anesthesia time, operative time, or hospital length of stay. Overall, the average length of stay was 0.6 days, readmission rate was 2%, and the total complication rate was 1% and there was no statistically significant difference between reconstruction groups. Harvesting of autograft was not associated with the overall 30-day complications and specific markers of health care utilization. Conclusions Our results are derived from the heterogeneous hospital setting of NSQIP contributing centers. The health care utilization and 30-day complications are low following corrective osteotomy of forearm long bones and autograft harvest did not influence the health care utilization. Level of Evidence Therapeutic Level II.

The storied state of economics

Abstract: Robert Shiller’s new book probes how social behaviour trumps statistics in determining the fate of economies — Tim Jackson reviews. Robert Shiller’s new book probes how social behaviour trumps statistics in determining the fate of economies — Tim Jackson reviews.