Deep learning prediction of renal anomalies for prenatal ultrasound diagnosis.

Deep learning algorithms have demonstrated remarkable potential in clinical diagnostics, particularly in the field of medical imaging. In this study, we investigated the application of deep learning models in early detection of fetal kidney anomalies. To provide an enhanced interpretation of those models' predictions, we proposed an adapted two-class representation and developed a multi-class model interpretation approach for problems with more than two labels and variable hierarchical grouping of labels. Additionally, we employed the explainable AI (XAI) visualization tools Grad-CAM and HiResCAM, to gain insights into model predictions and identify reasons for misclassifications. The study dataset consisted of 969 ultrasound images from unique patients; 646 control images and 323 cases of kidney anomalies, including 259 cases of unilateral urinary tract dilation and 64 cases of unilateral multicystic dysplastic kidney. The best performing model achieved a cross-validated area under the ROC curve of 91.28% ± 0.52%, with an overall accuracy of 84.03% ± 0.76%, sensitivity of 77.39% ± 1.99%, and specificity of 87.35% ± 1.28%. Our findings emphasize the potential of deep learning models in predicting kidney anomalies from limited prenatal ultrasound imagery. The proposed adaptations in model representation and interpretation represent a novel solution to multi-class prediction problems.

Sensory nerve release of CGRP increases tumor growth in HNSCC by suppressing TILs.

BACKGROUND: Perineural invasion (PNI) and nerve density within the tumor microenvironment (TME) have long been associated with worse outcomes in head and neck squamous cell carcinoma (HNSCC). This prompted an investigation into how nerves within the tumor microenvironment affect the adaptive immune system and tumor growth. METHODS: We used RNA sequencing analysis of human tumor tissue from a recent HNSCC clinical trial, proteomics of human nerves from HNSCC patients, and syngeneic orthotopic murine models of HPV-unrelated HNSCC to investigate how sensory nerves modulate the adaptive immune system. FINDINGS: Calcitonin gene-related peptide (CGRP) directly inhibited CD8 T cell activity in vitro, and blocking sensory nerve function surgically, pharmacologically, or genetically increased CD8 and CD4 T cell activity in vivo. CONCLUSIONS: Our data support sensory nerves playing a role in accelerating tumor growth by directly acting on the adaptive immune system to decrease Th1 CD4 T cells and activated CD8 T cells in the TME. These data support further investigation into the role of sensory nerves in the TME of HNSCC and points toward the possible treatment efficacy of blocking sensory nerve function or specifically inhibiting CGRP release or activity within the TME to improve outcomes. FUNDING: 1R01DE028282-01, 1R01DE028529-01, 1P50CA261605-01 (to S.D.K.), 1R01CA284651-01 (to S.D.K.), and F31 DE029997 (to L.B.D.).

An optimized protocol for isolation of murine pancreatic single cells with high yield and purity.

Here, we present a protocol for rapidly isolating single cells from the mouse pancreas, minimizing damage caused by digestive enzymes in exocrine cells. We guide you through steps to optimize the dissection sequence, enzyme composition, and operational procedures, resulting in high yields of viable pancreatic single cells. This protocol can be applied across a wide range of research areas, including single-cell sequencing, gene expression profiling, primary cell culture, and even the development of spheroids or organoids. For complete details on the use and execution of this protocol, please refer to Jiang et al. (2023).1.

Tff2 defines transit-amplifying pancreatic acinar progenitors that lack regenerative potential and are protective against Kras-driven carcinogenesis.

While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative progenitors (FPs). Here, we study a pancreatic acinar population marked by trefoil factor 2 (Tff2) expression. Long-term lineage tracing and single-cell RNA sequencing (scRNA-seq) analysis of Tff2-DTR-CreERT2-targeted cells defines a transit-amplifying progenitor (TAP) population that contributes to normal homeostasis. Following acute and chronic injury, Tff2+ cells, distinct from FPs, undergo depopulation but are eventually replenished. At baseline, oncogenic KrasG12D-targeted Tff2+ cells are resistant to PDAC initiation. However, KrasG12D activation in Tff2+ cells leads to survival and clonal expansion following pancreatitis and a cancer stem/progenitor cell-like state. Selective ablation of Tff2+ cells prior to KrasG12D activation in Mist1+ acinar or Dclk1+ FP cells results in enhanced tumorigenesis, which can be partially rescued by adenoviral Tff2 treatment. Together, Tff2 defines a pancreatic TAP population that protects against Kras-driven carcinogenesis.

Tumor Growth Rate Informs Treatment Efficacy in Metastatic Pancreatic Adenocarcinoma: Application of a Growth and Regression Model to Pivotal Trial and Real-World Data.

BACKGROUND: Methods for screening agents earlier in development and strategies for conducting smaller randomized controlled trials (RCTs) are needed. METHODS: We retrospectively applied a tumor growth model to estimate the rates of growth of pancreatic cancer using radiographic tumor measurements or serum CA 19-9 values from 3033 patients with stages III-IV PDAC who were enrolled in 8 clinical trials or were included in 2 large real-world data sets. RESULTS: g correlated inversely with OS and was consistently lower in the experimental arms than in the control arms of RCTs. At the individual patient level, g was significantly faster for lesions metastatic to the liver relative to those localized to the pancreas. Regardless of regimen, g increased toward the end of therapy, often by over 3-fold. CONCLUSIONS: Growth rates of PDAC can be determined using radiographic tumor measurement and CA 19-9 values. g is inversely associated with OS and can differentiate therapies within the same trial and across trials. g can also be used to characterize changes in the behavior of an individual's PDAC, such as differences in the growth rate of lesions based on metastatic site, and the emergence of chemoresistance. We provide examples of how g can be used to benchmark phase II and III clinical data to a virtual reference arm to inform go/no go decisions and consider novel trial designs to optimize and accelerate drug development.

Functional analysis of RYR1 variants in patients with confirmed susceptibility to malignant hyperthermia.

BACKGROUND: A major bottleneck to the introduction of noninvasive presymptomatic diagnostic tests for the pharmacogenetic disorder malignant hyperthermia is the lack of functional data for associated variants. METHODS: We screened 50 genes having a potential role in skeletal muscle calcium homeostasis using the HaloPlex™ (Agilent Technologies, Santa Clara, CA, USA) target enrichment system and next-generation sequencing. Twenty-one patients with a history of a clinical malignant hyperthermia reaction together with a positive in vitro contracture test were included. Eight variants in RYR1 were subsequently introduced into the cDNA for the human ryanodine receptor gene and tested in cultured human embryonic kidney (HEK293) cells for their effect on calcium release from intracellular stores in response to the ryanodine receptor-1 agonist 4-chloro-m-cresol using fura-2 as calcium indicator. Each variant was subjected to in silico curation using the European Malignant Hyperthermia Group scoring matrix and ClinGen RYR1 variant curation expert panel guidelines. RESULTS: Potentially causative RYR1 variants were identified in 15 patients. Of these, two families carried two RYR1 variants, five variants had been previously reported as 'pathogenic', two variants had been previously reported as 'likely benign', and eight were of 'uncertain significance'. Of these eight variants, four showed hypersensitivity to 4-chloro-m-cresol. Three variants were reclassified as either 'pathogenic' or 'likely pathogenic'. Two were classified as 'benign', whilst three remained of 'uncertain significance'. CONCLUSIONS: Three (p.Tyr1711Cys, p.Val2280Ile, and p.Arg4737Gln) additional variants can be added to the list of RYR1 disease-associated variants managed by the European Malignant Hyperthermia Group. These can therefore be used diagnostically in the future. Three variants (p.Glu2348Gly, p.Asn2634Lys, and p.Arg3629Trp) that remained classified as of uncertain significance require further family studies or a different functional test to determine clinical relevance in malignant hyperthermia.

Using deep-learning in fetal ultrasound analysis for diagnosis of cystic hygroma in the first trimester.

OBJECTIVE: To develop and internally validate a deep-learning algorithm from fetal ultrasound images for the diagnosis of cystic hygromas in the first trimester. METHODS: All first trimester ultrasound scans with a diagnosis of a cystic hygroma between 11 and 14 weeks gestation at our tertiary care centre in Ontario, Canada were studied. Ultrasound scans with normal nuchal translucency were used as controls. The dataset was partitioned with 75% of images used for model training and 25% used for model validation. Images were analyzed using a DenseNet model and the accuracy of the trained model to correctly identify cases of cystic hygroma was assessed by calculating sensitivity, specificity, and the area under the receiver-operating characteristic (ROC) curve. Gradient class activation heat maps (Grad-CAM) were generated to assess model interpretability. RESULTS: The dataset included 289 sagittal fetal ultrasound images;129 cystic hygroma cases and 160 normal NT controls. Overall model accuracy was 93% (95% CI: 88-98%), sensitivity 92% (95% CI: 79-100%), specificity 94% (95% CI: 91-96%), and the area under the ROC curve 0.94 (95% CI: 0.89-1.0). Grad-CAM heat maps demonstrated that the model predictions were driven primarily by the fetal posterior cervical area. CONCLUSIONS: Our findings demonstrate that deep-learning algorithms can achieve high accuracy in diagnostic interpretation of cystic hygroma in the first trimester, validated against expert clinical assessment.

Future directions in preclinical and translational cancer neuroscience research.

Recent advances in cancer neuroscience necessitate the systematic analysis of neural influences in cancer as potential therapeutic targets in oncology. Here, we outline recommendations for future preclinical and translational research in this field.

PD-1 Signaling Promotes Tumor-Infiltrating Myeloid-Derived Suppressor Cells and Gastric Tumorigenesis in Mice.

BACKGROUND & AIMS: Immune checkpoint inhibitors have limited efficacy in many tumors. We investigated mechanisms of tumor resistance to inhibitors of programmed cell death-1 (PDCD1, also called PD-1) in mice with gastric cancer, and the role of its ligand, PD-L1. METHODS: Gastrin-deficient mice were given N-methyl-N-nitrosourea (MNU) in drinking water along with Helicobacter felis to induce gastric tumor formation; we also performed studies with H/K-ATPase-hIL1B mice, which develop spontaneous gastric tumors at the antral-corpus junction and have parietal cells that constitutively secrete interleukin 1B. Mice were given injections of an antibody against PD-1 or an isotype control before tumors developed, or anti-PD-1 and 5-fluorouracil and oxaliplatin, or an antibody against lymphocyte antigen 6 complex locus G (also called Gr-1), which depletes myeloid-derived suppressor cells [MDSCs]), after tumors developed. We generated knock-in mice that express PD-L1 specifically in the gastric epithelium or myeloid lineage. RESULTS: When given to gastrin-deficient mice before tumors grew, anti-PD-1 significantly reduced tumor size and increased tumor infiltration by T cells. However, anti-PD-1 alone did not have significant effects on established tumors in these mice. Neither early nor late anti-PD-1 administration reduced tumor growth in the presence of MDSCs in H/K-ATPase-hIL-1ß mice. The combination of 5-fluorouracil and oxaliplatin reduced MDSCs, increased numbers of intra-tumor CD8+ T cells, and increased the response of tumors to anti-PD-1; however, this resulted in increased tumor expression of PD-L1. Expression of PD-L1 by tumor or immune cells increased gastric tumorigenesis in mice given MNU. Mice with gastric epithelial cells that expressed PD-L1 did not develop spontaneous tumors, but they developed more and larger tumors after administration of MNU and H felis, with accumulation of MDSCs. CONCLUSIONS: In mouse models of gastric cancer, 5-fluorouracil and oxaliplatin reduce numbers of MDSCs to increase the effects of anti-PD-1, which promotes tumor infiltration by CD8+ T cells. However, these chemotherapeutic agents also induce expression of PD-L1 by tumor cells. Expression of PD-L1 by gastric epithelial cells increases tumorigenesis in response to MNU and H felis, and accumulation of MDSCs, which promote tumor progression. The timing and site of PD-L1 expression is therefore important in gastric tumorigenesis and should be considered in design of therapeutic regimens.

Interleukin-1ß-induced pancreatitis promotes pancreatic ductal adenocarcinoma via B lymphocyte-mediated immune suppression.

OBJECTIVE: Long-standing chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC). Interleukin-1ß (IL-1ß) has been associated in PDAC with shorter survival. We employed murine models to investigate the mechanisms by which IL-1ß and chronic pancreatitis might contribute to PDAC progression. DESIGN: We crossed LSL-Kras+/G12D;Pdx1-Cre (KC) mice with transgenic mice overexpressing IL-1ß to generate KC-IL1ß mice, and followed them longitudinally. We used pancreatic 3D in vitro culture to assess acinar-to-ductal metaplasia formation. Immune cells were analysed by flow cytometry and immunohistochemical staining. B lymphocytes were adoptively transferred or depleted in Kras-mutant mice. B-cell infiltration was analysed in human PDAC samples. RESULTS: KC-IL1ß mice developed PDAC with liver metastases. IL-1ß treatment increased Kras+/G12D pancreatic spheroid formation. CXCL13 expression and B lymphocyte infiltration were increased in KC-IL1ß pancreata. Adoptive transfer of B lymphocytes from KC-IL1ß mice promoted tumour formation, while depletion of B cells prevented tumour progression in KC-IL1ß mice. B cells isolated from KC-IL1ß mice had much higher expression of PD-L1, more regulatory B cells, impaired CD8+ T cell activity and promoted tumorigenesis. IL-35 was increased in the KC-IL1ß pancreata, and depletion of IL-35 decreased the number of PD-L1+ B cells. Finally, in human PDAC samples, patients with PDAC with higher B-cell infiltration within tumours showed significantly shorter survival. CONCLUSION: We show here that IL-1ß promotes tumorigenesis in part by inducing an expansion of immune-suppressive B cells. These findings point to the growing significance of B suppressor cells in pancreatic tumorigenesis.

Acute Intestinal Inflammation Depletes/Recruits Histamine-Expressing Myeloid Cells From the Bone Marrow Leading to Exhaustion of MB-HSCs.

BACKGROUND & AIMS: Histidine decarboxylase (HDC), the histamine-synthesizing enzyme, is expressed in a subset of myeloid cells but also marks quiescent myeloid-biased hematopoietic stem cells (MB-HSCs) that are activated upon myeloid demand injury. However, the role of MB-HSCs in dextran sulfate sodium (DSS)-induced acute colitis has not been addressed. METHODS: We investigated HDC+ MB-HSCs and myeloid cells by flow cytometry in acute intestinal inflammation by treating HDC-green fluorescent protein (GFP) male mice with 5% DSS at various time points. HDC+ myeloid cells in the colon also were analyzed by flow cytometry and immunofluorescence staining. Knockout of the HDC gene by using HDC-/-; HDC-GFP and ablation of HDC+ myeloid cells by using HDC-GFP; HDC-tamoxifen-inducible recombinase Cre system; diphtheria toxin receptor (DTR) mice was performed. The role of H2-receptor signaling in acute colitis was addressed by treatment of DSS-treated mice with the H2 agonist dimaprit dihydrochloride. Kaplan-Meier survival analysis was performed to assess the effect on survival. RESULTS: In acute colitis, rapid activation and expansion of MB-HSC from bone marrow was evident early on, followed by a gradual depletion, resulting in profound HSC exhaustion, accompanied by infiltration of the colon by increased HDC+ myeloid cells. Knockout of the HDC gene and ablation of HDC+ myeloid cells enhance the early depletion of HDC+ MB-HSC, and treatment with H2-receptor agonist ameliorates the depletion of MB-HSCs and resulted in significantly increased survival of HDC-GFP mice with acute colitis. CONCLUSIONS: Exhaustion of bone marrow MB-HSCs contributes to the progression of DSS-induced acute colitis, and preservation of quiescence of MB-HSCs by the H2-receptor agonist significantly enhances survival, suggesting the potential for therapeutic utility.

Beyond the black stump: rapid reviews of health research issues affecting regional, rural and remote Australia.

CHAPTER 1: RETAIL INITIATIVES TO IMPROVE THE HEALTHINESS OF FOOD ENVIRONMENTS IN RURAL, REGIONAL AND REMOTE COMMUNITIES: Objective: To synthesise the evidence for effectiveness of initiatives aimed at improving food retail environments and consumer dietary behaviour in rural, regional and remote populations in Australia and comparable countries, and to discuss the implications for future food environment initiatives for rural, regional and remote areas of Australia. STUDY DESIGN: Rapid review of articles published between January 2000 and May 2020. DATA SOURCES: We searched MEDLINE (EBSCOhost), Health and Society Database (Informit) and Rural and Remote Health Database (Informit), and included studies undertaken in rural food environment settings in Australia and other countries. DATA SYNTHESIS: Twenty-one articles met the inclusion criteria, including five conducted in Australia. Four of the Australian studies were conducted in very remote populations and in grocery stores, and one was conducted in regional Australia. All of the overseas studies were conducted in rural North America. All of them revealed a positive influence on food environment or consumer behaviour, and all were conducted in disadvantaged, rural communities. Positive outcomes were consistently revealed by studies of initiatives that focused on promotion and awareness of healthy foods and included co-design to generate community ownership and branding. CONCLUSION: Initiatives aimed at improving rural food retail environments were effective and, when implemented in different rural settings, may encourage improvements in population diets. The paucity of studies over the past 20 years in Australia shows a need for more research into effective food retail environment initiatives, modelled on examples from overseas, with studies needed across all levels of remoteness in Australia. Several retail initiatives that were undertaken in rural North America could be replicated in rural Australia and could underpin future research. CHAPTER 2: WHICH INTERVENTIONS BEST SUPPORT THE HEALTH AND WELLBEING NEEDS OF RURAL POPULATIONS EXPERIENCING NATURAL DISASTERS?: Objective: To explore and evaluate health and social care interventions delivered to rural and remote communities experiencing natural disasters in Australia and other high income countries. STUDY DESIGN: We used systematic rapid review methods. First we identified a test set of citations and generated a frequency table of Medical Subject Headings (MeSH) to index articles. Then we used combinations of MeSH terms and keywords to search the MEDLINE (Ovid) database, and screened the titles and abstracts of the retrieved references. DATA SOURCES: We identified 1438 articles via database searches, and a further 62 articles via hand searching of key journals and reference lists. We also found four relevant grey literature resources. After removing duplicates and undertaking two stages of screening, we included 28 studies in a synthesis of qualitative evidence. DATA SYNTHESIS: Four of us read and assessed the full text articles. We then conducted a thematic analysis using the three phases of the natural disaster response cycle. CONCLUSION: There is a lack of robust evaluation of programs and interventions supporting the health and wellbeing of people in rural communities affected by natural disasters. To address the cumulative and long term impacts, evidence suggests that continuous support of people's health and wellbeing is needed. By using a lens of rural adversity, the complexity of the lived experience of natural disasters by rural residents can be better understood and can inform development of new models of community-based and integrated care services. CHAPTER 3: THE IMPACT OF BUSHFIRE ON THE WELLBEING OF CHILDREN LIVING IN RURAL AND REMOTE AUSTRALIA: Objective: To investigate the impact of bushfire events on the wellbeing of children living in rural and remote Australia. STUDY DESIGN: Literature review completed using rapid realist review methods, and taking into consideration the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement for systematic reviews. DATA SOURCES: We sourced data from six databases: EBSCOhost (Education), EBSCOhost (Health), EBSCOhost (Psychology), Informit, MEDLINE and PsycINFO. We developed search terms to identify articles that could address the research question based on the inclusion criteria of peer reviewed full text journal articles published in English between 1983 and 2020. We initially identified 60 studies and, following closer review, extracted data from eight studies that met the inclusion criteria. DATA SYNTHESIS: Children exposed to bushfires may be at increased risk of poorer wellbeing outcomes. Findings suggest that the impact of bushfire exposure may not be apparent in the short term but may become more pronounced later in life. Children particularly at risk are those from more vulnerable backgrounds who may have compounding factors that limit their ability to overcome bushfire trauma. CONCLUSION: We identified the short, medium and long term impacts of bushfire exposure on the wellbeing of children in Australia. We did not identify any evidence-based interventions for supporting outcomes for this population. Given the likely increase in bushfire events in Australia, research into effective interventions should be a priority. CHAPTER 4: THE ROLE OF NATIONAL POLICIES TO ADDRESS RURAL ALLIED HEALTH, NURSING AND DENTISTRY WORKFORCE MALDISTRIBUTION: Objective: Maldistribution of the health workforce between rural, remote and metropolitan communities contributes to longstanding health inequalities. Many developed countries have implemented policies to encourage health care professionals to work in rural and remote communities. This scoping review is an international synthesis of those policies, examining their effectiveness at recruiting and retaining nursing, dental and allied health professionals in rural communities. STUDY DESIGN: Using scoping review methods, we included primary research - published between 1 September 2009 and 30 June 2020 - that reported an evaluation of existing policy initiatives to address workforce maldistribution in high income countries with a land mass greater than 100 000 km2 . DATA SOURCES: We searched MEDLINE, Ovid Embase, Ovid Emcare, Informit, Scopus, and Web of Science. We screened 5169 articles for inclusion by title and abstract, of which we included 297 for full text screening. We then extracted data on 51 studies that had been conducted in Australia, the United States, Canada, United Kingdom and Norway. DATA SYNTHESIS: We grouped the studies based on World Health Organization recommendations on recruitment and retention of health care workers: education strategies (n = 27), regulatory change (n = 11), financial incentives (n = 6), personal and professional support (n = 4), and approaches with multiple components (n = 3). CONCLUSION: Considerable work has occurred to address workforce maldistribution at a local level, underpinned by good practice guidelines, but rarely at scale or with explicit links to coherent overarching policy. To achieve policy aspirations, multiple synergistic evidence-based initiatives are needed, and implementation must be accompanied by well designed longitudinal evaluations that assess the effectiveness of policy objectives. CHAPTER 5: AVAILABILITY AND CHARACTERISTICS OF PUBLICLY AVAILABLE HEALTH WORKFORCE DATA SOURCES IN AUSTRALIA: Objective: Many data sources are used in Australia to inform health workforce planning, but their characteristics in terms of relevance, accessibility and accuracy are uncertain. We aimed to identify and appraise publicly available data sources used to describe the Australian health workforce. STUDY DESIGN: We conducted a scoping review in which we searched bibliographic databases, websites and grey literature. Two reviewers independently undertook title and abstract screening and full text screening using Covidence software. We then assessed the relevance, accessibility and accuracy of data sources using a customised appraisal tool. DATA SOURCES: We searched for potential workforce data sources in nine databases (MEDLINE, Embase, Ovid Emcare, Scopus, Web of Science, Informit, the JBI Evidence-based Practice Database, PsycINFO and the Cochrane Library) and the grey literature, and examined several pre-defined websites. DATA SYNTHESIS: During the screening process we identified 6955 abstracts and examined 48 websites, from which we identified 12 publicly available data sources - eight primary and four secondary data sources. The primary data sources were generally of modest quality, with low scores in terms of reference period, accessibility and missing data. No single primary data source scored well across all domains of the appraisal tool. CONCLUSION: We identified several limitations of data sources used to describe the Australian health workforce. Establishment of a high quality, longitudinal, linked database that can inform all aspects of health workforce development is urgently needed, particularly for rural health workforce and services planning. CHAPTER 6: RAPID REALIST REVIEW OF OPIOID TAPERING IN THE CONTEXT OF LONG TERM OPIOID USE FOR NON-CANCER PAIN IN RURAL AREAS: Objective: To describe interventions, barriers and enablers associated with opioid tapering for patients with chronic non-cancer pain in rural primary care settings. STUDY DESIGN: Rapid realist review registered on the international register of systematic reviews (PROSPERO) and conducted in accordance with RAMESES standards. DATA SOURCES: English language, peer-reviewed articles reporting qualitative, quantitative and mixed method studies, published between January 2016 and July 2020, and accessed via MEDLINE, Embase, CINAHL Complete, PsycINFO, Informit or the Cochrane Library during June and July 2020. Grey literature relating to prescribing,deprescribing or tapering of opioids in chronic non-cancer pain, published between January 2016 and July 2020, was identified by searching national and international government, health service and peek organisation websites using Google Scholar. DATA SYNTHESIS: Our analysis of reported approaches to tapering conducted across rural and non-rural contexts showed that tapering opioids is complex and challenging, and identified several barriers and enablers. Successful outcomes in rural areas appear likely through therapeutic relationships, coordination and support, by using modalities and models of care that are appropriate in rural settings and by paying attention to harm minimisation. CONCLUSION: Rural primary care providers do not have access to resources available in metropolitan centres for dealing with patients who have chronic non-cancer pain and are taking opioid medications. They often operate alone or in small group practices, without peer support and access to multidisciplinary and specialist teams. Opioid tapering approaches described in the literature include regulation, multimodal and multidisciplinary approaches, primary care provider support, guidelines, and patient-centred strategies. There is little research to inform tapering in rural contexts. Our review provides a synthesis of the current evidence in the form of a conceptual model. This preliminary model could inform the development of a model of care for use in implementation research, which could test a variety of mechanisms for supporting decision making, reducing primary care providers' concerns about potential harms arising from opioid tapering, and improving patient outcomes.

Clinically Actionable Strategies for Studying Neural Influences in Cancer.

Neuro-glial activation is a recently identified hallmark of growing cancers. Targeting tumor hyperinnervation in preclinical and small clinical trials has yielded promising antitumor effects, highlighting the need of systematic analysis of neural influences in cancer (NIC). Here, we outline the strategies translating these findings from bench to the clinic.

Adult Pancreatic Acinar Progenitor-like Populations in Regeneration and Cancer.

The bulk of the pancreas primarily comprises long-lived acinar cells that are not considered a bona fide source for stem cells. However, certain acinar subpopulations have a repopulating capacity during regeneration, raising the hypothesis as to the presence of regenerative progenitor-like populations in the adult pancreas. Here, we describe recent discoveries based on fate-mapping techniques that support the existence of progenitor-like acinar subpopulations, including active progenitor-like cells that maintain tissue homeostasis and facultative progenitor-like cells that drive tissue regeneration. A possible link between progenitor-like acinar cells and cancer initiators is proposed. Further analysis of these cellular components is needed, because it would help uncover possible cellular sources for regeneration and cancer, as well as potential targets for therapy.

Roadmap for the Emerging Field of Cancer Neuroscience.

Mounting evidence indicates that the nervous system plays a central role in cancer pathogenesis. In turn, cancers and cancer therapies can alter nervous system form and function. This Commentary seeks to describe the burgeoning field of "cancer neuroscience" and encourage multidisciplinary collaboration for the study of cancer-nervous system interactions.

The determinants of maternal homocysteine in pregnancy: findings from the Ottawa and Kingston Birth Cohort.

OBJECTIVE: Observational studies have linked elevated homocysteine to vascular conditions. Folate intake has been associated with lower homocysteine concentration, although randomised controlled trials of folic acid supplementation to decrease the incidence of vascular conditions have been inconclusive. We investigated determinants of maternal homocysteine during pregnancy, particularly in a folic acid-fortified population. DESIGN: Data were from the Ottawa and Kingston Birth Cohort of 8085 participants. We used multivariable regression analyses to identify factors associated with maternal homocysteine, adjusted for gestational age at bloodwork. Continuous factors were modelled using restricted cubic splines. A subgroup analysis examined the modifying effect of MTHFR 677C>T genotype on folate, in determining homocysteine concentration. SETTING: Participants were recruited in Ottawa and Kingston, Canada, from 2002 to 2009. PARTICIPANTS: Women were recruited when presenting for prenatal care in the early second trimester. RESULTS: In 7587 participants, factors significantly associated with higher homocysteine concentration were nulliparous, smoking and chronic hypertension, while factors significantly associated with lower homocysteine concentration were non-Caucasian race, history of a placenta-mediated complication and folic acid supplementation. Maternal age and BMI demonstrated U-shaped associations. Folic acid supplementation of >1 mg/d during pregnancy did not substantially increase folate concentration. In the subgroup analysis, MTHFR 677C>T modified the effect of folate status on homocysteine concentration. CONCLUSIONS: We identified determinants of maternal homocysteine relevant to the lowering of homocysteine in the post-folic acid fortification era, characterised by folate-replete populations. A focus on periconceptional folic acid supplementation and improving health status may form an effective approach to lower homocysteine.

General practitioners and management of chronic noncancer pain: a cross-sectional survey of influences on opioid deprescribing.

BACKGROUND: General practitioners' (GPs) views about deprescribing prescription opioid analgesics (POAs) may influence the care provided for patients experiencing chronic noncancer pain (CNCP). There are limited data addressing GPs' beliefs about deprescribing, including their decisions to deprescribe different types of POAs. AIM: To determine the proportion of GPs who hold attitudes congruent with local pain stewardship, describe their deprescribing decisions, and determine whether type of POA influences deprescribing. DESIGN AND SETTING: In 2016, a cross-sectional survey of all GPs (n=1,570) in one mixed urban and regional primary health network (PHN) in Australia was undertaken. METHODS: A mailed self-report questionnaire assessed agreement with local guidelines for treating CNCP; influences on deprescribing POAs and likelihood of deprescribing in a hypothetical case involving either oral codeine or oxycodone. RESULTS: A response rate of 46% was achieved. Approximately half (54%) of GPs agreed POAs should be reserved for people with acute, cancer pain or palliative care and a third (32%) did not agree that a medication focus has limited benefits for peoples' long-term quality of life and function. Most (77%) GPs were less likely to deprescribe when effective alternate treatments were lacking, while various patient factors (eg, fear of weaning) were reported to decrease the likelihood of deprescribing for 25% of GPs. A significantly higher proportion of GPs reported being very likely to deprescribe codeine compared to the equivalent opioid dose of oxycodone for a hypothetical patient. CONCLUSIONS: Many GPs in the PHN hold attitudes at odds with local guidance that opioids are a nonsuperior treatment for CNCP. Attitudinal barriers to deprescribing include: a lack of consistent approach to deprescribing opioids as a class of drugs, perceived lack of effective treatment alternatives and patient fear of deprescribing. Therefore, the next step in this target population is to appropriately train and support GPs in how to apply the evidence in practice and how to support patients appropriately.

Cholinergic Signaling via Muscarinic Receptors Directly and Indirectly Suppresses Pancreatic Tumorigenesis and Cancer Stemness.

In many solid tumors, parasympathetic input is provided by the vagus nerve, which has been shown to modulate tumor growth. However, whether cholinergic signaling directly regulates progression of pancreatic ductal adenocarcinoma (PDAC) has not been defined. Here, we found that subdiaphragmatic vagotomy in LSL-Kras +/G12D;Pdx1-Cre (KC) mice accelerated PDAC development, whereas treatment with the systemic muscarinic agonist bethanechol restored the normal KC phenotype, thereby suppressing the accelerated tumorigenesis caused by vagotomy. In LSL-Kras +/G12D;LSL-Trp53 +/R172H;Pdx1-Cre mice with established PDAC, bethanechol significantly extended survival. These effects were mediated in part through CHRM1, which inhibited downstream MAPK/EGFR and PI3K/AKT pathways in PDAC cells. Enhanced cholinergic signaling led to a suppression of the cancer stem cell (CSC) compartment, CD11b+ myeloid cells, TNFα levels, and metastatic growth in the liver. Therefore, these data suggest that cholinergic signaling directly and indirectly suppresses growth of PDAC cells, and therapies that stimulate muscarinic receptors may be useful in the treatment of PDAC.Significance: Subdiaphragmatic vagotomy or Chrm1 knockout accelerates pancreatic tumorigenesis, in part via expansion of the CSC compartment. Systemic administration of a muscarinic agonist suppresses tumorigenesis through MAPK and PI3K/AKT signaling, in early stages of tumor growth and in more advanced, metastatic disease. Therefore, CHRM1 may represent a potentially attractive therapeutic target. Cancer Discov; 8(11); 1458-73. ©2018 AACR. This article is highlighted in the In This Issue feature, p. 1333.

Therapeutic alternatives for supporting GPs to deprescribe opioids: a cross-sectional survey.

BACKGROUND: GPs are central to opioid strategy in chronic non-cancer pain (CNCP). Lack of treatment alternatives and providers are common reasons cited for not deprescribing opioids. There are limited data about availability of multidisciplinary healthcare providers (MHCPs), such as psychologists, physiotherapists, or dietitians, who can provide broader treatments. AIM: To explore availability of MHCPs, and the association with GP opioid deprescribing and transition to therapeutic alternatives for CNCP. DESIGN & SETTING: Cross-sectional survey of all practising GPs (N = 1480) in one mixed urban and regional Australian primary health network. METHOD: A self-report mailed questionnaire assessed the availability of MHCPs and management of their most recent patient on long-term opioids for CNCP. RESULTS: Six hundred and eighty-one (46%) valid responses were received. Most GPs (71%) had access to a pain specialist and MHCPs within 50 km. GPs' previous referral for specialist support was significantly associated with access to a greater number of MHCPs (P = 0.001). Employment of a nurse increased the rate ratio of available MHCPs by 12.5% (incidence rate ratio [IRR] 1.125, 95% confidence interval [CI] = 1.001 to 1.264). Only one-third (32%) of GPs reported willingness to deprescribe and shift to broader CNCP treatments. Availability of MHCPs was not significantly associated with deprescribing decisions. CONCLUSION: Lack of geographical access to known MHCPs does not appear to be a major barrier to opioid deprescribing and shifting toward non-pharmacological treatments for CNCP. Considerable opportunity remains to encourage GPs' decision to deprescribe, with employment of a practice nurse appearing to play a role.