Identification of Cellular Interactions in the Tumor Immune Microenvironment Underlying CD8 T Cell Exhaustion

While immune checkpoint inhibitors show success in treating a subset of patients with certain late-stage cancers, these treatments fail in many other patients as a result of mechanisms that have yet to be fully characterized. The process of CD8 T cell exhaustion, by which T cells become dysfunctional in response to prolonged antigen exposure, has been implicated in immunotherapy resistance. Single-cell RNA sequencing (scRNA-seq) produces an abundance of data to analyze this process; however, due to the complexity of the process, contributions of other cell types to a process within a single cell type cannot be simply inferred. We constructed an analysis framework to first rank human skin tumor samples by degree of exhaustion in tumor-infiltrating CD8 T cells and then identify immune cell type-specific gene-regulatory network patterns significantly associated with T cell exhaustion. Using this framework, we further analyzed scRNA-seq data from human tumor and chronic viral infection samples to compare the T cell exhaustion process between these two contexts. In doing so, we identified transcription factor activity in the macrophages of both tissue types associated with this process. Our framework can be applied beyond the tumor immune microenvironment to any system involving cell-cell communication, facilitating insights into key biological processes that underpin the effective treatment of cancer and other complicated diseases.

Androgen blockade primes NLRP3 in macrophages to induce tumor phagocytosis

Immune-based therapies induce durable remissions in subsets of patients across multiple malignancies. However, there is limited efficacy of immunotherapy in metastatic castrate-resistant prostate cancer (mCRPC), manifested by an enrichment of immunosuppressive (M2) tumor- associated macrophages (TAM) in the tumor immune microenvironment (TME). Therefore, therapeutic strategies to overcome TAM-mediated immunosuppression are critically needed in mCRPC. Here we discovered that NLR family pyrin domain containing 3 (NLRP3), an innate immune sensing protein, is highly expressed in TAM from metastatic PC patients treated with standard-of-care androgen deprivation therapy (ADT). Importantly, ex vivo studies revealed that androgen receptor (AR) blockade in TAM upregulates NLRP3 expression, but not inflammasome activity, and concurrent AR blockade/NLRP3 agonist (NLRP3a) treatment promotes cancer cell phagocytosis by immunosuppressive M2 TAM. In contrast, NLRP3a monotherapy was sufficient to enhance phagocytosis of cancer cells in anti-tumor (M1) TAM, which exhibit high de novo NLRP3 expression. Critically, combinatorial treatment with ADT/NLRP3a in a murine model of advanced PC resulted in significant tumor control, with tumor clearance in 55% of mice via TAM phagocytosis. Collectively, our results demonstrate NLRP3 as an AR-regulated "macrophage phagocytic checkpoint", inducibly expressed in TAM by ADT and activated by NLRP3a treatment, the combination resulting in TAM-mediated phagocytosis and tumor control.

Brain white-matter changes associated with symptomatic acute COVID-19 infection in the neonatal period

We report an important case of periventricular white matter damage in a 1-month-old infant, demonstrated on high quality structural (T2) and diffusion weighted magnetic resonance imaging. The infant was born at term following an uneventful pregnancy and discharged home shortly after, but was brought to the paediatric emergency department five days after birth with seizures and respiratory distress, testing positive for COVID-19 infection on PCR. These images highlight the need to consider brain MRI in all infants with symptomatic SARS-Cov-2 infection, and show how this infection can lead to extensive white matter damage in the context of multisystem inflammation.

Abstract NG01: Dendritic cell intrinsic androgen receptor signaling reduces dendritic cell function and anti-tumor immunity

Sex differences in cancer susceptibility and mortality are well documented. In general, men have a higher cancer incidence and poorer outcomes when compared to women. Of immunologic relevance, and in contrast to cancer, women account for almost 80% of the autoimmune cases reported. These findings suggest male sex is a ‘risk factor’ for cancer but protective against autoimmunity and also highlight the potential involvement of sex hormones in regulating the immune response. Several recent publications have put a spotlight on androgen-mediated immune regulation and its impact on anti-tumor immunity. Guan and colleagues demonstrated that blockade of sex hormones in prostate tumor-bearing mice resulted in improved adaptive immune responses via direct modulation of CD8+ T cell-intrinsic androgen receptor signaling. Androgen-deprivation led to increased interferon gamma (IFNγ) expression by T cells and improved overall anti-tumor immunity. Additionally, others have shown using non-reproductive cancer mouse models (melanoma, bladder, colon and liver) that androgen receptor signaling promotes T cell exhaustion, and inhibits the activity and stemness of anti-tumor CD8+ T cells. Importantly, there is a clear role for androgen-mediated immune regulation in non-reproductive human cancer given a recent publication showing improved progression-free survival and overall survival in female versus male melanoma patients who were treated with neoadjuvant BRAF/MEK-targeted therapy. Follow-up preclinical mouse models showed significantly higher expression of the androgen receptor in tumors of both male and female BRAF/MEK-treated mice versus control and pharmacological inhibition of androgen receptor signaling improved responses to BRAF/MEK-targeted therapy in both male and female mice. Taken together, these publications stress the importance of understanding androgen-mediated immune control in both male and female cancer patients and the broad applicability of this signaling pathway in tissues including, but also beyond, the reproductive tract. There is mounting evidence to support a role androgen signaling in T cell biology. However, professional antigen presenting cells such as dendritic cells (DCs) are an essential part of generating robust anti-tumor T cell immunity were not addressed in these studies. Notably, DCs have been reported to be sensitive to androgens. Castration studies in mice found that removal of testosterone increased antigen presentation and expression of co-stimulatory molecules on DCs. In addition, hypogonadal men are at elevated risk of developing autoimmunity. Isolation of DCs from these patients showed a significant increase in DC maturation. HIV infected DCs derived from males produced significantly less type I interferon compared to female patients, resulting in weaker CD8 T cell responses against the virus. These data establish that androgens can shape DC function, yet they fall short in identifying the mechanisms of how androgens regulate DCs and the impact this may have on anti-tumor immunity. In our initial interrogation of a single-cell RNA sequencing dataset of human prostate cancer patients, we found that human tumors with low androgen receptor activity had increased IFNγ pathway activity and that IFNγ activity was positively associated with an increase in antigen presentation. Importantly, IFNγ is a cytokine that strongly induces antigen processing and presentation by antigen presenting cells and androgen deprivation therapy increases T cell derived IFNγ in tumor bearing mice suggesting that androgen receptor activity may also regulate antigen presentation. Furthermore, our analysis showed that elevated androgen receptor activity correlated with lower antigen presentation, conceivably through suppression of DC function. We hypothesized that inhibition of androgen receptor-mediated suppression of DC function would improve antigen presentation and anti-tumor T cell responses. Here we demonstrate using a B16 melanoma model that male and female DCs, both bone marrow-derived and those sorted from murine steady-state skin and melanoma tumors, express androgen receptor. Interestingly, there is a striking upregulation of androgen receptor expression specifically on type 1 conventional DCs (cDC1s) following uptake of tumor-derived antigen in vivo. cDC1s are a subset of DC that is particularly specialized in cross-presentation of exogenous antigens on MHCI. In this way, cDC1s are dominant drivers of CD8+ T cell responses and, via this function, have been shown to be essential for anti-tumor immunity. Further by inhibiting androgen receptor signaling in vitro using the clinically relevant inhibitor, enzalutamide, we find that bone marrow-derived DCs have increased phagocytic activity as shown by fluorescent bead uptake. Next, we injected male mice with B16 melanoma tumors and, after allowing the tumors to establish, we treated them with degarelix to reduce testosterone levels and enzalutamide to further inhibit androgen receptor signaling. On day 15 we sacrificed the mice, measured the tumors and interrogated DC function by flow cytometry. Strikingly, we found that inhibition of androgen receptor signaling in vivo significantly increased tumor-derived antigen uptake by cDC1s and, importantly, this correlated with improved tumor control as seen by significantly smaller tumors upon androgen receptor inhibition. These data provide insight into the regulation of DCs within the tumor microenvironment and how suppressing inhibitory hormone molecules may lead to better antigen presentation and more effective downstream T cell responses. Cancer immunotherapy is designed to generate an autoimmune-like response against an individual’s cancer. Given the striking sexual dimorphism in both autoimmunity and cancer, there is a clear and pressing need to investigate the impact of sex hormones on the effectiveness and function of cancer immunotherapy. And while myeloid cell targeted therapies and DC-based anti-tumor vaccines hold great promise for boosting anti-tumor T cells responses, current clinical use and efficacy has been limited pointing to an urgent need for improved vaccine and therapeutic design. This will rely on a better understanding of DC activation in this context. Our data indicates that there is a role for androgen receptor signaling in DC function and highlights the potential impact of DC-intrinsic androgen receptor inhibition on optimal DC vaccine design and the generation of more productive DC targeted immunotherapies.

Citation Format: Kasidy Brown, Fanny Polesso, Victoria Schuster, Amy Moran, Megan Ruhland. Dendritic cell intrinsic androgen receptor signaling reduces dendritic cell function and anti-tumor immunity. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr NG01.

A lineage specific role for PD-1 in agonist selection in the thymus

Effective peripheral T cell responses rely upon a diverse T cell repertoire, which is generated during the process of thymic selection. Signaling through the T cell receptor is critical in determining the lineage fate of developing thymocytes; however, it has been established that costimulatory molecules and cytokines can also contribute to fate decisions. Interestingly, coinhibitory molecules, such as programmed cell death protein 1 (PD-1), and their ligands are also expressed in the thymus. Expression of these molecules early in T cell development could regulate lineage fate decisions; however, their potential role in modulating T cell selection is not well-understood. We demonstrate that PD-1 is differentially expressed throughout thymocyte development. Additionally, we show that PD-1’s ligands, PD-L1 and PD-L2, are expressed by thymic epithelial cells. To elucidate the role of PD-1 signaling in regulating T cell selection, we examined mice deficient in PD-1 or PD-L1. Disrupting PD-1 signaling results in an increase in regulatory T cells (Tregs), but not other agonistly selected cell populations. This effect is dose-dependent as mice heterozygous for PD-1 or PD-L1 display an intermediate phenotype. Interestingly, our data suggest that PD-1’s regulation of Treg development is not through its inhibition of T cell receptor signaling, but rather through regulation of IL-2 cytokine production. These data demonstrate that PD-1 signaling restricts Treg development in the thymus, which broadens our understanding of the role of inhibitory proteins to include regulation of T cell development.

Supported by grants from NSF (GRFP AVPRS0015) and NIH (F31 CA261058-01).

Are we overtreating patients with malignant colorectal polyps? A 5-year review of the ACPGBI position statement

INTRODUCTION

In 2013, The Association of Coloproctology of Great Britain and Ireland (ACPGBI) issued a position statement regarding management of malignant polyps. We reviewed the management of endoscopically resected malignant colorectal polyps in a district general hospital to evaluate whether patients were being overtreated as per these guidelines.

METHODS

All patients who underwent a complete, non-piecemeal endoscopic removal of a malignant polyp between October 2013 and September 2018 were studied. Polyps were risk stratified for residual disease and followed up as per the ACPGBI. Patients were divided into two groups based on management after polypectomy. Primary outcome measured was the presence of residual tumour or involved lymph nodes in the resection specimen. Secondary outcomes included complications and recurrence.

RESULTS

Thirty-three patients were included: 21 in the non-operative group (NOG) and 12 in the operative group (OG). The ACPGBI risk score in the NOG varied between 1 and over 4 compared with the OG who all scored over 4. Two patients in the OG (16%) demonstrated residual disease. Five patients suffered a postoperative complication. No recurrences were noted in the OG and one in the NOG.

CONCLUSION

Our findings against a backdrop of the available literature suggest that the risk of residual disease after malignant polypectomy may not be as high as stated by the ACPGBI. As a result, there is a risk of overtreating patients and exposing them to the significant complications of surgery if careful consideration is not exercised.

One size does not fit all: reaching agricultural workers in South Africa with TB services

BACKGROUND: Despite decreasing incidence of TB in South Africa, people with TB continue to be missed by facility-based case-finding interventions, and agricultural workers suffer disproportionately from limited access to services. We implemented two community-based active case-finding strategies to engage agricultural workers and assessed the cost of these interventions.METHODS: We summarized costs for two interventions - one led by enrolled nurses and one by non-governmental organizations (NGOs) - from April 2017 to December 2019, and calculated cost per person reached by services, screened for TB, identified as having TB and started on TB treatment. We performed Mann-Kendall tests of monotonic trend and conducted a sensitivity analysis of intervention costs.RESULTS: The enrolled nurses-led implementation started 442 people on TB treatment at a cost of US$118 per person, with decreasing trend in costs over the implementation period (P = 0.005). The NGO-led intervention started 160 people on treatment at a cost of US$554 per person, with decreasing trend in costs over the implementation period (P = 0.004).CONCLUSION: Community-based case-finding strategies find TB patients who would be missed by the health system. These strategies should be scaled up to close the missing cases gap in South Africa and to meet UN targets for ending TB.

QUALITY OF LIFE IN BREAST CANCER SURVIVORS: AN ASSESSMENT OF INTERNATIONAL BREAST CANCER DRAGON BOAT RACERS

Resistance exercise is deemed safe for women recovering from conventional breast cancer therapies but few clinicians are aware that dragon boat racing, as a form of resistive exercise, is available to the breast cancer community. The objectives of this study were to 1) increase clinician awareness of dragon boat racing (DBR) in breast cancer survivors as a community-based physical activity, and 2) evaluate quality of life (QOL) in breast cancer survivors with or without lymphedema who participate in DBR. This prospective, observational study surveyed 1,069 international breast cancer dragon boat racers from eight countries to compare function, activity, and participation in women with and without self-reported lymphedema using the Lymph-ICF questionnaire. Seventy-one percent of women (n=758) completed the questionnaires. Results revealed significantly higher Lymph-ICF scores in the lymphedema participants, signifying reduced QOL, when compared to the nonlymphedema participants (p<0.05), except for "go on vacation" for which no statistical difference was reported (p=0.20). International breast cancer survivors with lymphedema participating in DBR at an international competition had reduced function, limited activity, and restricted participation compared to participants without lymphedema. Clinicians should consider utilizing DBR as a community-based activity to support exercise and physical activity after a breast cancer diagnosis.

Brown and beige adipose tissue regulate systemic metabolism through a metabolite interorgan signaling axis

Brown and beige adipose tissue are emerging as distinct endocrine organs. These tissues are functionally associated with skeletal muscle, adipose tissue metabolism and systemic energy expenditure, suggesting an interorgan signaling network. Using metabolomics, we identify 3-methyl-2-oxovaleric acid, 5-oxoproline, and β-hydroxyisobutyric acid as small molecule metabokines synthesized in browning adipocytes and secreted via monocarboxylate transporters. 3-methyl-2-oxovaleric acid, 5-oxoproline and β-hydroxyisobutyric acid induce a brown adipocyte-specific phenotype in white adipocytes and mitochondrial oxidative energy metabolism in skeletal myocytes both in vitro and in vivo. 3-methyl-2-oxovaleric acid and 5-oxoproline signal through cAMP-PKA-p38 MAPK and β-hydroxyisobutyric acid via mTOR. In humans, plasma and adipose tissue 3-methyl-2-oxovaleric acid, 5-oxoproline and β-hydroxyisobutyric acid concentrations correlate with markers of adipose browning and inversely associate with body mass index. These metabolites reduce adiposity, increase energy expenditure and improve glucose and insulin homeostasis in mouse models of obesity and diabetes. Our findings identify beige adipose-brown adipose-muscle physiological metabokine crosstalk.

Telehealth sounds a bit challenging, but it has potential: participant and physiotherapist experiences of gym-based exercise intervention for Achilles tendinopathy monitored via telehealth

Background

Although telehealth is becoming more popular for delivery of care for individuals with musculoskeletal pain, to our knowledge telehealth has not been used to manage Achilles tendinopathy. This research aimed to explore the experience of participants and physiotherapists with gym-based exercise interventions for Achilles tendinopathy monitored via videoconference.

Methods

A qualitative, interpretive description design was performed using semi-structured interviews (8 participants) and a focus group (7 physiotherapists). Participants and physiotherapists were interviewed about their experiences of the use of telehealth during a gym-based exercise intervention incorporating different calf load parameters for Achilles tendinopathy. We employed an inductive thematic analysis approach to analyse the data.

Results

Three themes identified from both participants and physiotherapists included i) acceptability of telehealth; ii) enablers to adherence with telehealth; and iii) barriers to adherence with telehealth. Two extra themes arose from participants regarding adherence with gym-based exercise, including enablers to adherence with the exercise intervention, and barriers to adherence with the exercise intervention. Both participants and physiotherapists expressed overall satisfaction and acceptability of telehealth monitoring of gym-based exercise.

Conclusion

Gym-based exercise intervention for Achilles tendinopathy involving weekly telehealth monitoring was acceptable to both participants and physiotherapists. Potential enablers and barriers were identified that may improve adherence to this type of intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03907-w.

Sexual dimorphism in adipose tissue mitochondrial function and metabolic flexibility in obesity

OBJECTIVE

The prevalence of obesity is growing globally. Adiposity increases the risk for metabolic syndrome, type 2 diabetes and cardiovascular disease. Adipose tissue distribution influences systemic metabolism and impacts metabolic disease risk. The link between sexual dimorphisms of adiposity and metabolism is poorly defined. We hypothesise that depot-specific adipose tissue mitochondrial function contributes to the sexual dimorphism of metabolic flexibility in obesity.

METHODS

Male and female mice fed high fat diet (HFD) or standard diet (STD) from 8-18 weeks of age underwent whole animal calorimetry and high-resolution mitochondrial respirometry analysis on adipose tissue depots. To determine translatability we used RT-qPCR to examine key brown adipocyte-associated gene expression: peroxisome proliferator-activated receptor co-activator 1α, Uncoupling protein 1 and cell death inducing DFFA like effector a in brown adipose tissue (BAT) and subcutaneous adipose tissue (sWAT) of 18-week-old mice and sWAT from human volunteers.

RESULTS

Male mice exhibited greater weight gain compared to female mice when challenged with HFD. Relative to increased body mass, the adipose to body weight ratio for BAT and sWAT depots was increased in HFD-fed males compared to female HFD-fed mice. Oxygen consumption, energy expenditure, respiratory exchange ratio and food consumption did not differ between males and females fed HFD. BAT mitochondria from obese females showed increased Complex I & II respiration and maximal respiration compared to lean females whereas obese males did not exhibit adaptive mitochondrial BAT respiration. Sexual dimorphism in BAT-associated gene expression in sWAT was also associated with Body Mass Index in humans.

CONCLUSIONS

We show that sexual dimorphism of weight gain is reflected in mitochondrial respiration analysis. Female mice have increased metabolic flexibility to adapt to changes in energy intake by regulating energy expenditure through increased complex II and maximal mitochondrial respiration within BAT when HFD challenged and increased proton leak in sWAT mitochondria.

Controlled Growth Factor Release in 3D-Printed Hydrogels

Growth factors (GFs) are critical components in governing cell fate during tissue regeneration. Their controlled delivery is challenging due to rapid turnover rates in vivo. Functionalized hydrogels, such as heparin-based hydrogels, have demonstrated great potential in regulating GF release. While the retention effects of various concentrations and molecular weights of heparin have been investigated, the role of geometry is unknown. In this work, 3D printing is used to fabricate GF-embedded heparin-based hydrogels with arbitrarily complex geometry (i.e., teabag, flower shapes). Simplified cylindrical core-shell structures with varied shell thickness are printed, and the rates of GF release are measured over the course of 28 days. Increasing the shell layers' thickness decreases the rate of GF release. Additionally, a mathematical model is developed, which is found capable of accurately predicting GF release kinetics in hydrogels with shell layers greater than 0.5 mm thick (R2 > 0.96). Finally, the sequential release is demonstrated by printing two GFs in alternating radial layers. By switching the spatial order, the delivery sequence of the GFs can be modulated. This study demonstrates how 3D printing can be utilized to fabricate user-defined structures with unique geometry in order to control the rate of GF release in hydrogels.

Examining the cost of community-based tuberculosis treatment in South Africa

SETTING: While South Africa has improved access to tuberculosis (TB) treatment and care, the 2015 treatment success rate for multidrug-resistant TB (MDR-TB) remains low, at 55%. Community-based TB treatment and care improves patient retention compared to the standard of care alone.OBJECTIVE: To assess the cost of a USAID-funded community-based TB model in Nelson Mandela Bay Health District (NMBHD), Eastern Cape Province, South Africa compared to the national standard of care alone.DESIGN: We estimated the cost of community-based DR-TB treatment and adherence support compared to the standard of care alone.RESULTS: Average overall costs were US$2827 lower per patient on the community-based model than the standard of care alone.CONCLUSION: The per-patient cost of the community-based model is lower than the standard of care alone. Assuming the costs and effects of a community-based model implemented in NMBHD were observed at a larger scale, implementing the model could reduce overall health system costs.

PD-1/PD-L1 signaling regulates the thymic niche size of agonistly selected T cells

Effective peripheral T cell responses rely upon a diverse T cell repertoire, generated during thymic selection. Signaling through the TCR establishes thresholds for thymocyte selection in order to create this repertoire. Because co-stimulation modifies TCR signaling, it may contribute to the regulation of T cell development by determining signal strength thresholds that direct thymocytes into specific lineages. Programmed death-1 (PD-1), a member of the B7/CD28 family of costimulatory/inhibitory receptors, has been implicated in the development of thymocytes because it is expressed in CD4− CD8− double-negative thymocytes during TCRb rearrangement. Further, the ligands for PD-1, PD-L1 and PD-L2, are expressed on thymic epithelial cells. PD-L2 is restricted to the medulla whereas PD-L1 is expressed throughout the thymus. Here, we show that PD-1 modulates agonist selection, a process in which some high-affinity thymocytes will mature into unconventional T cell lineages (e.g. regulatory T cells, NKT cells). Transgenic mice lacking either PD-L1 or PD-1 have increased numbers of agonistly selected T cells compared to wildtype animals. Interestingly, loss of PD-L1 increases the selection of conventional and agonistly selected T cells whereas loss of PD-1 limits the phenotype to agonist lineages. These data demonstrate that PD-1, PD-L1, and possibly PD-L2 interactions, potentially within the thymic microenvironment in which they are expressed, play a role in determining T cell fate and shaping the final T cell repertoire.

Androgen receptor targeted therapy sensitizes tumor bearing mice to effective immunotherapy

Sex hormones impact both the innate and adaptive immune response, contributing to differences in autoimmune diseases, response to infection, and cancer incidence between males and females. Androgens are known to exert a general immunosuppressive effect. Historically, immune checkpoint blockade (ICB) has not proven to be efficacious in patients with prostate cancer despite standard of care consisting of androgen deprivation therapy (ADT). Upon disease progression, men will be treated with second line ADT therapy; some of which can prevent androgen receptor transcriptional activity. One such drug is enzalutamide. Given T cells express AR, we hypothesized that enzalutamide treatment would relieve the immunosuppressive effects of androgens on T cells, rendering them more responsive to immunotherapy. In the studies presented, we sensitize castration resistant prostate cancer tumor bearing mice to effective ICB with a combination of castration and enzalutamide. This combination therapy leads to ~40% tumor rejection and long-term survival; an effect that is dependent on CD8 T cells. These tumor infiltrating CD8 T cells made 6-fold more IFNγ within the tumor in the triple therapy group compared to control group. Surprisingly, this combination therapy showed efficacy in the androgen independent sarcoma tumor model MCA-205. Using in vitro and in vivo assays, we show that enzalutamide has a direct effect on T cell function. Taken together, our data suggests that ADT, and specifically enzalutamide treatment, can sensitize tumor bearing animals to effective immune checkpoint blockade and allow for tumor control by T cells.

Inorganic Nitrate Promotes Glucose Uptake and Oxidative Catabolism in White Adipose Tissue Through the XOR-Catalyzed Nitric Oxide Pathway

An aging global population combined with sedentary lifestyles and unhealthy diets has contributed to an increasing incidence of obesity and type 2 diabetes. These metabolic disorders are associated with perturbations to nitric oxide (NO) signaling and impaired glucose metabolism. Dietary inorganic nitrate, found in high concentration in green leafy vegetables, can be converted to NO in vivo and demonstrates antidiabetic and antiobesity properties in rodents. Alongside tissues including skeletal muscle and liver, white adipose tissue is also an important physiological site of glucose disposal. However, the distinct molecular mechanisms governing the effect of nitrate on adipose tissue glucose metabolism and the contribution of this tissue to the glucose-tolerant phenotype remain to be determined. Using a metabolomic and stable-isotope labeling approach, combined with transcriptional analysis, we found that nitrate increases glucose uptake and oxidative catabolism in primary adipocytes and white adipose tissue of nitrate-treated rats. Mechanistically, we determined that nitrate induces these phenotypic changes in primary adipocytes through the xanthine oxidoreductase-catalyzed reduction of nitrate to NO and independently of peroxisome proliferator-activated receptor-α. The nitrate-mediated enhancement of glucose uptake and catabolism in white adipose tissue may be a key contributor to the antidiabetic effects of this anion.

3D printing of a biocompatible double network elastomer with digital control of mechanical properties

The majority of 3D-printed biodegradable biomaterials are brittle, limiting their potential application to compliant tissues. Poly (glycerol sebacate) acrylate (PGSA) is a synthetic biodegradable and biocompatible elastomer, compatible with light-based 3D printing. In this work we employed digital-light-processing (DLP)-based 3D printing to create a complex PGSA network structure. Nature-inspired double network (DN) structures with two geometrically interconnected segments with different mechanical properties were printed from the same material in a single shot. Such capability has not been demonstrated by any other fabrication technique. The biocompatibility of PGSA after 3D printing was confirmed via cell-viability analysis. We used a finite element analysis (FEA) model to predict the failure of the DN structure under uniaxial tension. FEA confirmed the soft segments act as sacrificial elements while the hard segments retain structural integrity. The simulation demonstrated that the DN design absorbs 100% more energy before rupture than the network structure made by single exposure condition (SN), doubling the toughness of the overall structure. Using the FEA-informed design, a new DN structure was printed and the FEA predicted tensile test results agreed with tensile testing of the printed structure. This work demonstrated how geometrically-optimized material design can be easily and rapidly achieved by using DLP-based 3D printing, where well-defined patterns of different stiffnesses can be simultaneously formed using the same elastic biomaterial, and overall mechanical properties can be specifically optimized for different biomedical applications.

Abstract PR10: Heterogenous activation of multiple suppressive pathways by scRNAseq may underscore resistance to PD-1 therapy in metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is a deadly disease that, until recently, was thought to be resistant to checkpoint blockade. A recent clinical trial revealed that the PD-1 inhibitor, pembrolizumab, when given in combination with the androgen-deprivation therapy (ADT) drug enzalutamide, achieved an unprecedented 18% complete biochemical response rate in mCRPC patients. Though promising, ~80% of these patients failed to respond and the mechanisms of resistance remain unclear. The immunologic landscape of mCRPC is largely unknown. We hypothesize that mechanisms of resistance to anti-PD-1 therapy may reflect the heterogeneity of immune suppression in this disease. Revealing this heterogeneity is difficult to achieve because access to the metastatic disease is limited to core-needle biopsies of largely bone and lymph node disease. Therefore, to reveal pathways of resistance, we developed a protocol for isolating leukocytes and performing single-cell RNAseq from fresh core-needle biopsies taken from enzalutamide-resistant metastatic lesions prior to and after pembrolizumab treatment. The abundance of tumor-infiltrating leukocytes was on average less than 1% of total cells independent of biopsy location. Using our single-cell RNA sequencing data, we generated a leukocyte gene signature of enzalutamide mCRPC and used this to retrospectively deconvolute bulk RNA sequencing data from a cohort of 16 paired biopsies from enzalutamide-naive and -resistant patients. Computational approaches revealed the diverse leukocyte heterogeneity of mCRPC and multiple suppressive pathways beyond PD-1 within the tumor microenvironment. Importantly, the suppressive pathways were shared between metastatic biopsy locations (i.e., bone vs lymph node). To validate these targets in combination with ADT treatment, we developed orthotopic mouse models of mCRPC in immunocompetent mice. These strategies will identify new opportunities for clinical intervention to enhance antitumor responses in this patient population.

This abstract is also being presented as Poster A04.

Citation Format: Chaojie Wang, Julie Graff, Zheng Xia, Amy Moran. Heterogenous activation of multiple suppressive pathways by scRNAseq may underscore resistance to PD-1 therapy in metastatic castration-resistant prostate cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr PR10.

Abstract A38: Targeting the androgen receptor to increase sensitivity to checkpoint immunotherapy

Advanced prostate cancer is the second leading cause of cancer-associated mortality in men with ~32,000 deaths each year. Castration-resistant prostate cancer has no cure and an overall survival of approximately 5 years. Strategies to block androgen receptor (AR) signaling form the backbone of prostate-cancer therapy and despite suppression of serum testosterone, intratumor concentrations of androgens can remain high. Blocking AR nuclear translocation and its transcriptional function delays disease progression, but not overall survival, in castration-resistant prostate cancer patients. In a paradigm-challenging clinical trial, anti-PD-1 blockade induced long-term durable responses in a subset of metastatic castration-resistant prostate cancer patients treated with the AR inhibitor, enzalutamide. Interestingly, T cells also express AR and their function can be directly modulated by changes in androgen availability. Given this and the success of this clinical trial, we asked if enzalutamide sensitized T cells to checkpoint immunotherapy. Using in vitro and in vivo assays, we reveal a direct effect of enzalutamide on T-cell proliferation and function. In a novel implantable mouse model of advanced prostate cancer, we highlight a requirement for androgen receptor blockade to sensitize prostate tumor-bearing animals to immunotherapy. Transcriptomic analysis of leukocytes from the tumor and draining lymph node revealed a small cohort of genes differentially regulated by enzalutamide that are consistent with increased sensitivity to checkpoint blockade. Perhaps most significant, in patients who responded to anti-PD-1 therapy, some of these same genes were upregulated prior to treatment, suggesting these could be a biomarker for immunotherapy sensitization in advanced prostate cancer patients. Taken together, our data suggest a novel mechanism targeting androgen receptor-mediated immune suppression to improve immunotherapy outcomes in advanced prostate cancer.

Note:This abstract was not presented at the conference.

Citation Format: Archana Sehrawat, Fanny Polesso, Christina Hipfinger, Xiangnan Guan, Zheng Xia, Julie Graff, Amy Moran. Targeting the androgen receptor to increase sensitivity to checkpoint immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A38.

Quality of life in breast cancer survivors: An assessment of international breast cancer dragon boat racers

Resistance exercise is deemed safe for women recovering from conventional breast cancer therapies but few clinicians are aware that dragon boat racing, as a form of resistive exercise, is available to the breast cancer community. The objectives of this study were to 1) increase clinician awareness of dragon boat racing (DBR) in breast cancer survivors as a community-based physical activity, and 2) evaluate quality of life (QOL) in breast cancer survivors with or without lymphedema who participate in DBR. This prospective, observational study surveyed 1,069 international breast cancer dragon boat racers from eight countries to compare function, activity, and participation in women with and without selfreported lymphedema using the Lymph-ICF questionnaire. Seventy-one percent of women (n=758) completed the questionnaires. Results revealed significantly higher Lymph-ICF scores in the lymphedema participants, signifying reduced QOL, when compared to the nonlymphedema participants (p<0.05), except for "go on vacation" for which no statistical difference was reported (p=0.20). International breast cancer survivors with lymphedema participating in DBR at an international competition had reduced function, limited activity, and restricted participation compared to participants without lymphedema. Clinicians should consider utilizing DBR as a community-based activity to support exercise and physical activity after a breast cancer diagnosis.

Effects of a Six-Month Multi-Ingredient Nutrition Supplement Intervention of Omega-3 Polyunsaturated Fatty Acids, vitamin D, Resveratrol, and Whey Protein on Cognitive Function in Older Adults: A Randomised, Double-Blind, Controlled Trial

OBJECTIVES

To investigate the impact of a six-month multi-ingredient nutrition supplement intervention (Smartfish®), containing omega-3 polyunsaturated fatty acids (PUFAs), vitamin D, resveratrol, and whey protein, on cognitive function in Irish older adults.

DESIGN

Double-blind, randomised controlled trial (ClinicalTrials.gov: NCT02001831). A quantitative, mixed-model design was employed in which the dependent variable (cognitive function) was analysed with a between-subjects factor of group (placebo, intervention) and within-subjects factor of testing occasion (baseline, three-months, six-months).

SETTING

Community-based intervention including assessments conducted at University College Dublin, Ireland.

PARTICIPANTS

Thirty-seven community-dwelling older adults (68-83 years; mean (x̄)= 75.14 years; standard deviation (SD)= 3.64; 18 males) with normal cognitive function (>24 on the Mini Mental State Examination) were assigned to the placebo (n= 17) or intervention (n= 20) via a block randomisation procedure.

INTERVENTION

Daily consumption for six-months of a 200mL liquid juice intervention comprising 3000mg omega-3 PUFAs [1500mg docosahexaenoic acid (DHA) and 1500mg eicosapentaenoic acid (EPA)], 10μg vitamin D3, 150mg resveratrol and 8g whey protein isolate. The placebo contained 200mL juice only.

MEASUREMENTS

A standardised cognitive assessment battery was conducted at baseline and follow-ups. Individual test scores were z-transformed to generate composite scores grouped into cognitive domains: executive function, memory, attention and sensorimotor speed. Motor imagery accuracy and subjective awareness of cognitive failures variables were computed from raw scores.

RESULTS

A hierarchical statistical approach was used to analyse the data; first, by examining overall cognitive function, then by domain, and then by individual test scores. Using mixed between-within subjects, analyses of variance (ANOVAs), no significant differences in overall cognitive function or composite cognitive domains were observed between groups over time. The only significant interaction was for Stroop Color-Word Time (p< 0.05). The intervention group demonstrated reduced task completion time at three- and six-month follow-ups, indicating enhanced performance.

CONCLUSION

The present nutrition intervention encompassed a multi-ingredient approach targeted towards improving cognitive function, but overall had only a limited beneficial impact in the older adult sample investigated. Future investigations should seek to establish any potential clinical applications of such targeted interventions with longer durations of supplementation, or in populations with defined cognitive deficits.

PRP‑1 significantly decreases the ALDHhigh cancer stem cell population and regulates the aberrant Wnt/β‑catenin pathway in human chondrosarcoma JJ012 cells

Chondrosarcomas are malignant bone tumors refractory to chemotherapy and radiation treatment; thus, novel therapeutic strategies are required. Proline-rich polypeptide 1 (PRP-1) has previously demonstrated antitumor properties in chondrosarcoma. To further investigate the role of PRP-1 in chondrosarcoma cells, its effects on cancer stem cell (CSC) populations were determined by analyzing aldehyde dehydrogenase (ALDH) activity, an established marker of CSCs, in association with regulation of the Wnt/β-catenin signaling. A significant decrease in ALDH^high CSCs was observed following treatment of chondrosarcoma JJ012 cells with PRP-1. For RT² profiler PCR array analysis of Wnt/β-catenin signaling genes, cells were sorted into: i) Bulk JJ012 cells; ii) ALDH^high cells sorted from untreated JJ012 cells (ALDH^{high-untreated}); and iii) ALDH^low cells sorted from PRP-1-treated JJ012 cells (ALDH^low-PRP-1). The expression levels of Wnt/β-catenin signaling genes were determined to be downregulated in the ALDH^{high-untreated} cells and upregulated in ALDH^low-PRP-1 cells when compared to the bulk JJ012 cells. Additionally, two important oncogenes involved in this pathway, MMP7 and CCND2, were found to be downregulated in the ALDH^low-PRP-1 cells. Immunocytochemistry demonstrated the localization of β-catenin in the nuclei of the PRP-1-treated cells. Western blotting indicated increased β-catenin expression in the ALDH^low-PRP-1 cells compared with the bulk JJ012 cells. Analysis of the cytoplasmic and nuclear fractions of cells treated with increasing concentrations of PRP-1 and β-catenin nuclear translocation inhibitor CGP57380, suggested the nuclear translocation of β-catenin following PRP-1 treatment. In addition, treatment of JJ012 cells with a specific ALDH inhibitor, diethylaminobenzaldehyde, and PRP-1 resulted in a significant decrease in cytoplasmic β-catenin protein expression. This indicated that ALDH inactivation may be associated with the nuclear translocation of β-catenin. Derivation of sarcomas from mesenchymal stem cells via inactivation of the Wnt pathway has been previously documented. The findings of the present study support the notion that Wnt/β-catenin activation may serve a differential role in sarcomas, limiting tumor progression in association with decreased CSC activity.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Process measure of FAST tuberculosis infection control demonstrates delay in likely effective treatment

SETTING

The tuberculous infection control strategy, FAST (Find cases Actively, Separate safely and Treat effectively), recommends prompt initiation of likely effective anti-tuberculosis treatment informed by Xpert^® MTB/RIF results.OBJECTIVE: To describe FAST implementation at Quang Nam Provincial TB and Lung Disease Hospital (QNH), Tam Ky, Viet Nam, using time to initiation of effective TB treatment as a process measure.

DESIGN

Hospital logs were used to calculate the time to likely effective treatment in patients with pulmonary TB (PTB) hospitalised during the study period.

RESULTS

Between 1 January and 31 December 2016, of 858 patients treated for PTB, 493 (57.5%) received likely effective treatment. The median time to likely effective treatment was 3 days (interquartile range 2.0-6.0), with 213 (43.2%) patients receiving likely effective treatment within 2 days. Of 81 patients receiving likely effective treatment for drug-susceptible TB with a positive Xpert result as their initial in-patient diagnostic test, 64 (79.0%) received likely effective treatment within 2 days compared with 10 (5.7%) who were initially smear-negative then found to be Xpert-positive (P < 0.0001).

CONCLUSIONS

A 'time to' process measure of the FAST tuberculous infection control strategy indicates delays in the initiation of likely effective anti-tuberculosis treatment in a resource-limited hospital. Expanding access to Xpert may speed time to likely effective treatment.

3D bioprinting of hydrogels for retina cell culturing

Recapitulating native retina environment is crucial in isolation and culturing of retina photoreceptors (PRs). To date, maturation of PRs remains incomprehensible in vitro. Here we present a strategy of integrating the physical and chemical signals through 3D-bioprinting of hyaluronic acid (HA) hydrogels and co-differentiation of retinal progenitor cells (RPCs) into PRs with the support of retinal-pigment epithelium (RPEs). To mimic the native environment during retinal development, we chemically altered the functionalization of HA hydrogels to match the compressive modulus of HA hydrogels with native retina. RPEs were incorporated in the culturing system to support the differentiation due to their regeneration capabilities. We found that HA with a specific functionalization can yield hydrogels with compressive modulus similar to native retina. This hydrogel is also suitable for 3D bioprinting of retina structure. The results from cell study indicated that derivation of PRs from RPCs was improved in the presence of RPEs.

Low-Dose Anti-Thymocyte Globulin (ATG) Preserves β-Cell Function and Improves HbA1c in New-Onset Type 1 Diabetes

OBJECTIVE

A pilot study suggested that combination therapy with low-dose anti-thymocyte globulin (ATG) and pegylated granulocyte colony-stimulating factor (GCSF) preserves C-peptide in established type 1 diabetes (T1D) (duration 4 months to 2 years). We hypothesized that 1) low-dose ATG/GCSF or 2) low-dose ATG alone would slow the decline of β-cell function in patients with new-onset T1D (duration <100 days).

RESEARCH DESIGN AND METHODS

A three-arm, randomized, double-masked, placebo-controlled trial was performed by the Type 1 Diabetes TrialNet Study Group in 89 subjects: 29 subjects randomized to ATG (2.5 mg/kg intravenously) followed by pegylated GCSF (6 mg subcutaneously every 2 weeks for 6 doses), 29 to ATG alone (2.5 mg/kg), and 31 to placebo. The primary end point was mean area under the curve (AUC) C-peptide during a 2-h mixed-meal tolerance test 1 year after initiation of therapy. Significance was defined as one-sided P value < 0.025.

RESULTS

The 1-year mean AUC C-peptide was significantly higher in subjects treated with ATG (0.646 nmol/L) versus placebo (0.406 nmol/L) (P = 0.0003) but not in those treated with ATG/GCSF (0.528 nmol/L) versus placebo (P = 0.031). HbA_1c was significantly reduced at 1 year in subjects treated with ATG and ATG/GCSF, P = 0.002 and 0.011, respectively.

CONCLUSIONS

Low-dose ATG slowed decline of C-peptide and reduced HbA_1c in new-onset T1D. Addition of GCSF did not enhance C-peptide preservation afforded by low-dose ATG. Future studies should be considered to determine whether low-dose ATG alone or in combination with other agents may prevent or delay the onset of the disease.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

A reference high-pressure CO2 adsorption isotherm for ammonium ZSM-5 zeolite: results of an interlaboratory study

This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess carbon dioxide adsorption isotherms on NIST Reference Material RM 8852 (ammonium ZSM-5 zeolite), at 293.15 K (20 °C) from 1 kPa up to 4.5 MPa. Eleven laboratories participated in this exercise and, for the first time, high-pressure adsorption reference data are reported using a reference material. An empirical reference equationn e x = d ( 1 + exp [ - ln ( P ) + a / b ] ) c , [n ex -surface excess uptake (mmol/g), P-equilibrium pressure (MPa), a = -6.22, b = 1.97, c = 4.73, and d = 3.87] along with the 95% uncertainty interval (U k = 2 = 0.075 mmol/g) were determined for the reference isotherm using a Bayesian, Markov Chain Monte Carlo method. Together, this zeolitic reference material and the associated adsorption data provide a means for laboratories to test and validate high-pressure adsorption equipment and measurements. Recommendations are provided for measuring reliable high-pressure adsorption isotherms using this material, including activation procedures, data processing methods to determine surface excess uptake, and the appropriate equation of state to be used.

Sustainable Synthesis and Characterization of Bisphenol A-Free Polycarbonate from Six-Membered Dicyclic Carbonate

Bisphenol A, (2,2-bis(4-hydroxyphenyl)propane, BPA)-free polycarbonate (PC) from six-membered di-cyclic carbonate, di-trimethylolpropane di-cyclic carbonate (DTMPC) was developed as a new type of PC by ring opening homo-polymerization. The polymerization was controlled by using metal-free organic-based catalyst systems. The results indicated that the conversion rate depends on the basicity of the catalyst in the order of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 4-dimethylaminopyridine (DMAP), triethylamine (TEA) from high to low. Over 99% conversion of DTMPC was obtained at 130°C within 15 min by TBD, DBU and DMAP. The resulting PC as a homo-polymer showed high optical transparency and hardness, low swelling property in organic solvents, and thermally stable at temperatures as high as 200 °C. High cell viability as the cyto-compatibility of C3H 10T1/2 cells seeded directly on the surface of PC films was obtained. This implied that PC is a viable material for biomedical and consumer products applications where safety is an important consideration.

The role of cognitive training in endourology: a randomised controlled trial

INTRODUCTION

Cognitive training is an important training modality which allows the user to rehearse a procedure without physically carrying it out. This has led to recent interests to incorporate cognitive training within surgical education but research is currently limited. The use of cognitive training in surgery is not clear-cut and so this study aimed to determine whether, relative to a control condition, the use of cognitive training improves technical surgical skills on a ureteroscopy simulator, and if so whether one cognitive training method is superior.

METHODS

This prospective, comparative study recruited 59 medical students and randomised them to one of three groups: control- simulation training only (n=20), flashcards cognitive training group (n=20) or mental imagery cognitive training group (n=19). All participants completed three tasks at baseline on the URO Mentor simulator followed by the cognitive intervention if randomised to receive it. Participants then returned to perform an assessment task on the simulator. Outcome measures from the URO Mentor performance report was used for analysis and a quantitative survey was given to all participants to assess usefulness of training received.

RESULTS

This study showed cognitive training to have minimal effects on technical skills of participants. The mental imagery group had fewer laser misfires in the assessment task when compared to both control and flashcards group (P=.017, P=.036, respectively). The flashcards group rated their preparation to be most useful when compared to control (P=.0125). Other parameters analysed between the groups did not reach statistical significance. Cognitive training was found to be feasible and cost effective when carried out in addition to simulation training.

CONCLUSION

This study has shown that the role of cognitive training within acquisition of surgical skills is minimal and that no form of cognitive training was superior to another. Further research needs to be done to evaluate other ways of performing cognitive training.

Sick Note to Fit Note: one trust's project to improve usage by hospital clinicians

Introduction

In April 2010, the government introduced a new Statement of Fitness to Work or 'Fit Note' for patients requiring time off of work or adaptations to their work due to illness. Responsibility to issue these documents has shifted from primary to secondary care. Hospital clinicians are required to issue for inpatients and for outpatients where clinical responsibility has not been taken over by the general practitioner (GP). However, awareness of this change is lacking. Misdirecting patients to their GP for the sole purpose of receiving a 'Fit Note' is an unnecessary use of appointment time and negatively impacts on patients. King's College Hospital NHS Trust receives a number of quality alerts from primary care regarding this issue.

Methods

A trust-wide educational initiative was designed and implemented to increase staff awareness of Fit Notes and their correct usage in order to reduce the number of patients being misdirected to their GP to obtain one. Interventions included direct staff engagement, a trust-wide promotional campaign and creation of an electronic version of the document.

Results

Uptake of the electronic version of the Fit Note has steadily increased and there has been a fall in the number of quality alerts received by the trust. However, staff awareness on the whole remains low.

Conclusions

Patients being misdirected to their general practice for Fit Notes is an important issue and one on which the baseline level of awareness among hospital clinicians is low. Challenges during this intervention have been in penetrating a trust of this size and getting the message across to staff. However, digitising the Fit Note can help to increase its use.

Inviting a statistician to join an evidence-based journal club

AIMS AND METHOD

In response to frequent cancellations, we recently changed the format of our journal club. We invited a statistician to attend and each meeting focused specifically on critical appraisal and statistical analysis. Active learning principles were used where every participant critically appraised an aspect of the paper presented at each meeting. The aim of this paper was to evaluate the impact of the new format on attendance and satisfaction levels. Attendance and satisfaction levels were measured in the 3 months before and the 3 months after the new format was introduced.

RESULTS

Average attendance increased from 10 to 15, with two psychologists and two trainees who did not work in the hospital starting to attend regularly. Satisfaction levels also increased significantly with respect to academic interest, enjoyment, usefulness and overall satisfaction.

CONCLUSION

Combining statistical expertise with principles of active learning has led to increased satisfaction levels among participants in our journal club.

Integrating Brain Science into Health Studies: An Interdisciplinary Course in Contemplative Neuroscience and Yoga

As neuroscience knowledge grows in its scope of societal applications so does the need to educate a wider audience on how to critically evaluate its research findings. Efforts at finding teaching approaches that are interdisciplinary, accessible and highly applicable to student experience are thus ongoing. The article describes an interdisciplinary undergraduate health course that combines the academic study of contemplative neuroscience with contemplative practice, specifically yoga. The class aims to reach a diverse mix of students by teaching applicable, health-relevant neuroscience material while directly connecting it to first-hand experience. Outcomes indicate success on these goals: The course attracted a wide range of students, including nearly 50% non-science majors. On a pre/post test, students showed large increases in their knowledge of neuroscience. Students' ratings of the course overall, of increases in positive feelings about its field, and of their progress on specific course objectives were highly positive. Finally, students in their written work applied neuroscience course content to their personal and professional lives. Such results indicate that this approach could serve as a model for the interdisciplinary, accessible and applied integration of relevant neuroscience material into the undergraduate health curriculum.

Alteration of palatine ruga pattern in subjects with oligodontia: A pilot study

INTRODUCTION

The aim of this study was to compare the palatal ruga patterns in subjects with oligodontia and normal tooth numbers.

METHODS

An observational investigation was conducted by using maxillary dental study casts to compare ruga numbers, lengths, and shapes in subjects with diagnosed oligodontia or normal tooth numbers.

RESULTS

A total of 32 subjects comprised both the oligodontia (mean age, 14.0 years; SD, 5.0 years) and the control (mean age, 14.5 years; SD, 5.1 years) groups. The mean number of missing teeth in the oligodontia group was 8.7. The mean number of rugae in the whole sample was 7.36 (SD, 1.16), with no significant difference between the groups (P = 0.264). For ruga pattern, no differences were found for right-sided rugae; however, on the left side, a significant difference existed in shape frequency associated with ruga 2. Specifically, a curved shape was seen more frequently in ruga 2 of the oligodontia group (P = 0.01).

CONCLUSIONS

The identification of subtle differences in ruga patterns between subjects with oligodontia and normal tooth numbers suggests potentially shared pathways during the development of these oral structures. Further large-scale investigations are warranted.

Sitagliptin Treatment After Total Pancreatectomy With Islet Autotransplantation: A Randomized, Placebo-Controlled Study

Insulin independence after total pancreatectomy and islet autotransplant (TPIAT) for chronic pancreatitis is limited by a high rate of postprocedure beta cell apoptosis. Endogenous glucagon-like peptide-1 and glucose-dependent insulinotropic peptide, which are increased by dipeptidyl peptidase 4 inhibitor therapy (sitagliptin) may protect against beta cell apoptosis. To determine the effect of sitagliptin after TPIAT, 83 adult TPIAT recipients were randomized to receive sitagliptin (n = 54) or placebo (n = 29) for 12 months after TPIAT. At 12 and 18 months after TPIAT, participants were assessed for insulin independence; metabolic testing was performed with mixed meal tolerance testing and frequent sample intravenous glucose tolerance testing. Insulin independence did not differ between the sitagliptin and placebo groups at 12 months (42% vs. 45%, p = 0.82) or 18 months (36% vs. 44%, p = 0.48). At 12 months, insulin dose was 9.0 (standard error 1.7) units/day and 7.9 (2.2) units/day in the sitagliptin and placebo groups, respectively (p = 0.67) and at 18 months 10.3 (1.9) and 7.1 (2.6) units/day, respectively (p = 0.32). Hemoglobin A_1c levels and insulin secretory measures were similar in the two groups, as were adverse events. In conclusion, sitagliptin could be safely administered but did not improve metabolic outcomes after TPIAT.