A taste of space: Remote animal observations and discrete-choice models provide new insights into foraging and density dynamics for a large subarctic herbivore

Competition for resources and space can drive forage selection of large herbivores from the bite through the landscape scale. Animal behaviour and foraging patterns are also influenced by abiotic and biotic factors. Fine-scale mechanisms of density-dependent foraging at the bite scale are likely consistent with density-dependent behavioural patterns observed at broader scales, but few studies have directly tested this assertion. Here, we tested if space use intensity, a proxy of spatiotemporal density, affects foraging mechanisms at fine spatial scales similarly to density-dependent effects observed at broader scales in caribou. We specifically assessed how behavioural choices are affected by space use intensity and environmental processes using behavioural state and forage selection data from caribou (Rangifer tarandus granti) observed from GPS video-camera collars using a multivariate discrete-choice modelling framework. We found that the probability of eating shrubs increased with increasing caribou space use intensity and cover of Salix spp. shrubs, whereas the probability of eating lichen decreased. Insects also affected fine-scale foraging behaviour by reducing the overall probability of eating. Strong eastward winds mitigated negative effects of insects and resulted in higher probabilities of eating lichen. At last, caribou exhibited foraging functional responses wherein their probability of selecting each food type increased as the availability (% cover) of that food increased. Space use intensity signals of fine-scale foraging were consistent with density-dependent responses observed at larger scales and with recent evidence suggesting declining reproductive rates in the same caribou population. Our results highlight potential risks of overgrazing on sensitive forage species such as lichen. Remote investigation of the functional responses of foraging behaviours provides exciting future applications where spatial models can identify high-quality habitats for conservation.

Investigation and response to an outbreak of Neisseria meningitidis serogroup Y ST-1466 urogenital infections, Australia

Abstract

In 2023, an increased number of urogenital and anorectal infections with Neisseria meningitis serogroup Y (MenY) were reported in New South Wales (NSW). Whole genome sequencing (WGS) found a common sequence type (ST-1466), with limited sequence diversity. Confirmed outbreak cases were NSW residents with a N. meningitidis isolate matching the cluster sequence type; probable cases were NSW residents with MenY isolated from a urogenital or anorectal site from 1 July 2023 without WGS testing. Of the 41 cases, most were men (n = 27), of whom six reported recent contact with a female sex worker. Five cases were men who have sex with men and two were female sex workers. Laboratory alerts regarding the outbreak were sent to all Australian jurisdictions through the laboratories in the National Neisseria Network. Two additional states identified urogenital MenY ST-1466 infections detected in late 2023. Genomic analysis showed all MenY ST-1466 sequences were interspersed, suggestive of an Australia-wide outbreak. The incidence of these infections remains unknown, due to varied testing and reporting practices both within and across jurisdictions. Isolates causing invasive meningococcal disease (IMD) in Australia are typed, and there has been no MenY ST-1466 IMD recorded in Australia to end of March 2024. Concerns remain regarding the risk of IMD, given the similarity of these sequences with a MenY ST-1466 IMD strain causing a concurrent outbreak in the United States of America.

PLS3 missense variants affecting the actin-binding domains cause X-linked congenital diaphragmatic hernia and body-wall defects

Congenital diaphragmatic hernia (CDH) is a relatively common and genetically heterogeneous structural birth defect associated with high mortality and morbidity. We describe eight unrelated families with an X-linked condition characterized by diaphragm defects, variable anterior body-wall anomalies, and/or facial dysmorphism. Using linkage analysis and exome or genome sequencing, we found that missense variants in plastin 3 (PLS3), a gene encoding an actin bundling protein, co-segregate with disease in all families. Loss-of-function variants in PLS3 have been previously associated with X-linked osteoporosis (MIM: 300910), so we used in silico protein modeling and a mouse model to address these seemingly disparate clinical phenotypes. The missense variants in individuals with CDH are located within the actin-binding domains of the protein but are not predicted to affect protein structure, whereas the variants in individuals with osteoporosis are predicted to result in loss of function. A mouse knockin model of a variant identified in one of the CDH-affected families, c.1497G>C (p.Trp499Cys), shows partial perinatal lethality and recapitulates the key findings of the human phenotype, including diaphragm and abdominal-wall defects. Both the mouse model and one adult human male with a CDH-associated PLS3 variant were observed to have increased rather than decreased bone mineral density. Together, these clinical and functional data in humans and mice reveal that specific missense variants affecting the actin-binding domains of PLS3 might have a gain-of-function effect and cause a Mendelian congenital disorder.

Cancer-associated mesothelial cells are regulated by the anti-Müllerian hormone axis

Cancer-associated mesothelial cells (CAMCs) in the tumor microenvironment are thought to promote growth and immune evasion. We find that, in mouse and human ovarian tumors, cancer cells express anti-Müllerian hormone (AMH) while CAMCs express its receptor AMHR2, suggesting a paracrine axis. Factors secreted by cancer cells induce AMHR2 expression during their reprogramming into CAMCs in mouse and human in vitro models. Overexpression of AMHR2 in the Met5a mesothelial cell line is sufficient to induce expression of immunosuppressive cytokines and growth factors that stimulate ovarian cancer cell growth in an AMH-dependent way. Finally, syngeneic cancer cells implanted in transgenic mice with Amhr2-/- CAMCs grow significantly slower than in wild-type hosts. The cytokine profile of Amhr2-/- tumor-bearing mice is altered and their tumors express less immune checkpoint markers programmed-cell-death 1 (PD1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4). Taken together, these data suggest that the AMH/AMHR2 axis plays a critical role in regulating the pro-tumoral function of CAMCs in ovarian cancer.

Abstract 1321: New mouse models of metastatic lung cancer

INTRODUCTION: Lung cancer is the leading cause of cancer deaths worldwide and greater than 75% of human lung cancer deaths can be attributed to metastasis. Metastatic disease in most existing mouse models of pulmonary adenocarcinoma is typically sporadic and often requires aging mice for several months. These factors limit the usefulness of most current mouse models for basic and pre-clinical research aimed at identifying mechanisms and effective treatments of metastatic disease. We have developed two novel mouse models of metastatic lung cancer and report here on changes in protein expression and immune cell recruitment in the lungs of these models.

METHODS AND RESULTS: Mouse models were generated by adding mutations in Dicer1, an RNAse III enzyme within the microRNA (miRNA) biosynthesis pathway, to a mouse model of Kras-driven pulmonary adenocarcinoma. For both models, tumorigenesis was induced by conditional expression of an oncogenic allele of Kras (KrasG12D), deletion of both alleles of Trp53 and deletion of one allele of Dicer1 in one cell type and the expression of a truncated Dicer1 allele in a different cell type. In the absence of Dicer1 truncation, mice expressing KrasG12D and deleting Trp53 in club cells have a reported median survival of 28.6 weeks after tumor induction. We detected accelerated development of pulmonary adenocarcinoma and lymph node metastasis (12.1 weeks) only when we induced tumorigenesis in club cells and truncated DICER1 in alveolar type II (ATII) cells. Induction of tumorigenesis in ATII cells and truncation of DICER1 in club cells did not accelerate tumorigenesis or metastasis. To evaluate the molecular and cellular changes in the different phenotypes of these models we have characterized protein expression, using spatial proteomics, and immune cell recruitment, using flow cytometry.

CONCLUSIONS: Through cell type specific truncation/deletion of Dicer1 we have generated a new mouse model that rapidly develops pulmonary adenocarcinomas and metastatic disease. Our findings support our hypothesis that tumorigenesis and metastasis are influenced by miRNA regulated communication between different cell types. Preliminary flow cytometry and spatial proteomic analyses have suggested cellular targets underlying phenotypic differences between our two mouse models. These models have potential for both understanding the basic processes of metastasis and for pre-clinical studies aimed at preventing and/or treating metastatic lung cancer.

Citation Format: Paige Ramkissoon, Julie Wells, Richard S. Maser, Jiayuan Shi, Zheng Gong, Qing Li, Brian Hoffmann, Anne Marchini, Elaine Bechtel, Rosalinda Doty, Gary Ren, Carol J. Bult. New mouse models of metastatic lung cancer [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 1321.

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial

OBJECTIVES

To determine if a newer design of total knee replacement (TKR) (Journey II BCS) produces superior patient-reported outcomes scores and biomechanical outcomes than the older, more established design (Genesis II).

SETTING

Patients were recruited from an NHS University Hospital between July 2018 and October 2019 with surgery at two sites. Biomechanical and functional capacity measurements were at a University Movement and Exercise Laboratory.

PARTICIPANTS

80 participants undergoing single-stage TKR.

INTERVENTIONS

Patients were randomised to receive either the Journey II BCS (JII-BCS) or Genesis II TKR.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was the Oxford Knee Score (OKS), at 6 months. Secondary outcomes were: OKS Activity and Participation Questionnaire, EQ-5D-5L and UCLA Activity scores, Timed Up and Go Test, 6 min walk test, lower limb kinematics and lower limb muscle activity during walking and balance.

RESULTS

This study found no difference in the OKS between groups. The OKS scores for the JII-BCS and Genesis II groups were mean (SD) 42.97 (5.21) and 43.13 (5.20) respectively, adjusted effect size 0.35 (-2.01,2.71) p=0.771In secondary outcome measures, the Genesis II group demonstrated a significantly greater walking range-of-movement (50.62 (7.33) vs 46.07 (7.71) degrees, adjusted effect size, 3.14 (0.61,5.68) p=0.02) and higher peak knee flexion angular velocity during walking (mean (SD) 307.69 (38.96) vs 330.38 (41.40) degrees/second, adjusted effect size was 21.75 (4.54,38.96), p=0.01) and better postural control (smaller resultant centre of path length) during quiet standing than the JII-BCS group (mean (SD) 158.14 (65.40) vs 235.48 (176.94) mm, adjusted effect size, 59.91 (-105.98, -13.85) p=0.01.).

CONCLUSIONS

In this study population, the findings do not support the hypothesis that the Journey II BCS produces a better outcome than the Genesis II for the primary outcome of the OKS at 6 months after surgery.

TRIAL REGISTRATION NUMBER

ISRCTN32315753.

Abstract 927: Developing new mouse models of metastatic lung cancer

INTRODUCTION: The focus of this work is to develop new mouse models for metastatic lung cancer. Lung cancer is the leading cause of cancer deaths worldwide and greater than 75% of human lung cancer deaths can be attributed to metastasis. Metastatic disease in most existing mouse models of pulmonary adenocarcinoma is typically sporadic and often requires aging mice for several months. These factors limit the usefulness of mouse models for basic and pre-clinical research aimed at identifying effective treatments of metastatic disease.

METHODS AND RESULTS: We have developed new mouse models of pulmonary adenocarcinoma in which we added mutations in Dicer1, an RNAse III enzyme within the microRNA (miRNA) biosynthesis pathway to a mouse model of Kras-driven pulmonary adenocarcinoma. For both models, we induced tumorigenesis by conditionally expressing an oncogenic allele of Kras (KrasG12D), deleting of both alleles of Trp53 and deleting one allele of Dicer1 in one cell population then expressing truncated Dicer1 in a different cell population. In the absence of Dicer1 truncation, mice expressing KrasG12D and deleting Trp53 in Club cells have a reported median survival of 28.6 weeks after tumor induction. When we also deleted one allele of Dicer1 in Club cells and truncated Dicer1 in alveolar type II cells of these mice, they exhibited respiratory distress and began dying 12.1 weeks after tumor induction. In our initial pilot study, all animals (12/12) developed pulmonary adenocarcinoma and 30% (3/10) had lymph node metastasis. We did not observe accelerated tumorigenesis, however, when we switched cell types, inducing tumorigenesis in alveolar type II cells and truncating Dicer1 in Club cells, or when induced tumorigenesis and truncating Dicer1 within the same cell populations.

CONCLUSIONS: Through cell type specific truncation/deletion of Dicer1 we have generated a new mouse model that rapidly develops pulmonary adenocarcinomas and metastatic disease. Our findings support our hypothesis that tumorigenesis and metastasis are influenced by miRNA regulated communication between different cell types. These models have potential for both understanding the basic processes of metastasis and for pre-clinical studies aimed at preventing and/or treating metastatic lung cancer.

Citation Format: Julie Wells, Richard Maser, Ashley Tucker, Teresa McGee, Wendy Memishian, Rosalinda Doty, Carol J. Bult. Developing new mouse models of metastatic lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 927.

A248 THE ROLE OF DIETARY TRYPTOPHAN IN INDOLE AND KYNURENINE PRODUCTION AND IMMUNE MODULATION IN HEALTHY INDIVIDUALS

Background

Natural supplements are widely consumed by the general public, with little evidence of mechanistic support. Tryptophan has gained central attention, being transformed by host and gut microbial enzymes into multiple bioactive metabolites that regulate immunity and mood. Indoles are activators of the aryl hydrocarbon receptor (AhR), crucial for the maintenance of intestinal homeostasis. Tryptophan has been advocated to prevent chronic inflammatory conditions, however the clinical data to support this are missing.

Aims

To investigate clinical, immune, and metabolic parameters in response to tryptophan supplementation, in healthy subjects on a low tryptophan diet.

Methods

We performed a randomized, double blind, placebo-controlled crossover study in 20 healthy volunteers (18 - 75 years old). Subjects were instructed to start a low tryptophan diet and then randomly assigned to a 3-week tryptophan supplementation (3g/day) or placebo, in enteric coated capsules. After a 2-week washout period, subjects crossed over to the opposite intervention arm. Questionnaires were used to assess bowel symptoms, anxiety, depression and stress levels (GSRS, HADS and DASS21, respectively). Stool, urine, blood and duodenal aspirates were collected to measure tryptophan metabolites and cytokines.

Results

Tryptophan supplementation had no changes in gastrointestinal symptoms or behavioral parameters. Compared with placebo, tryptophan increased urinary and plasma levels of indoleamine 2,3-dioxygenase/kynurenine (p= 0.002 and p= 0.02, respectively) and indoles (p= 0.001 and p= 0.01, respectively), suggestive of activation of host and microbial metabolic pathways. Urinary and plasma metabolites were higher than in feces (p=<0.05), suggesting their active absorption in the small intestine. There were no differences in AhR activity in duodenal aspirates or in stool. Although no changes in the cytokine production were detected, serum kynurenine pathway metabolites negatively correlated with IL-8 levels (R=-0.72; p=0.001). Fecal tryptophan metabolites levels positively correlated with anxiety and depression scores, suggesting that the microbial metabolism of dietary tryptophan in the colon impacts host behavior.

Conclusions

Tryptophan supplementation in healthy individuals was safe and had a measurable influence on microbial and host metabolism, mainly kynurenine and indole pathways, with known immunomodulatory properties. Tryptophan was metabolized and absorbed in the small intestine, reflected by the high metabolite levels in plasma and urine. Fecal metabolites correlating with clinical parameters reflect subjects’ long-term diet. Further studies are warranted to study tryptophan supplementation in disorders with altered AhR pathways.

Funding Agencies

CIHR

Socioeconomic disparities in growth trajectories of Chinese children and adolescents during 1991-2015

Backgrounds

Socioeconomic (SEP) disparities in growth of children from low-/middle-income countries are not well understood, especially in countries experiencing rapid economic growth. We investigated how SEP disparities in child growth in China have changed over time.

Methods

Using the longitudinal data of 5,118 children and adolescents (7-18y) from China Health and Nutrition Survey (10 sweeps, 1991-2015), we derived four cohorts born in 1981-95, 1986-90, 1991-95, 1996-2000. We applied random-effects fractional polynomial models to estimate mean height and BMI trajectories for each gender separately, by socioeconomic position (SEP) for each cohort. SEP disparities were estimated as differences between high and low SEP groups (by community-level urbanization index, household income/capita, parental education, and occupational class). We also examined whether SEP disparities in nutritional status (stunting, thinness, overweight/obesity) have changed over time.

Results

Mean height and BMI increased across cohorts, with differences being greatest in adolescence. The increasing trend for height was similar in high and low SEP groups, thus positive SEP differences in mean height persisted across cohorts (e.g. for boys at 10y, were 3.8cm in the earliest and 2.9cm latest cohorts at by urbanization index, and were 3.6cm and 3.1cm by HH income). For BMI, the increasing trend was much faster in high (vs low) SEP groups, thus SEP differences in mean BMI increased across cohorts (e.g. for boys at 10y, increased from 0.5 to 0.8kg/m2 by urbanization index, and 0.4 to 1.1kg/m2 by HH income). Findings for stunting and overweight/obesity were consistent with those for height and BMI. No significant association was found between SEP and thinness.

Conclusions

Short stature is associated with lower SEP, whereas high BMI is associated with higher SEP among Chinese youths. Between 1991-2015 in China, inequalities in childhood BMI increased while those for height remained fairly constant.

Key messages

Short stature is associated with lower SEP, whereas high BMI is associated with higher SEP among Chinese youths. Between 1991-2015 in China, inequalities in childhood BMI increased while those for height remained fairly constant.

A cross-sectional study to evaluate the validity of a novel patient-reported outcome measure of medication adherence in Type 2 Diabetes

Introduction

The average medication adherence (MA) among patients in developed countries living with a chronic disease is estimated to be roughly 50%.(1) Non-adherence is multi-factorial, owing to socio-economic and clinical factors, as well as arguably the most important factor, patients’ health beliefs and experiences. Patient Reported Outcome Measures (PROMs) are often uni-dimensional in their assessment of drivers of MA. This study has evaluated a novel PROM as part of a wider international research initiative focused on Type 2 Diabetes (T2D) which assesses four key factors of MA referred to as Social (S), Psychological (P), Usage (U) and Rationale (R), in short SPUR®.

Aim

To compare the validity of SPUR® against previously validated PROMs in patients with T2D.

Methods

This South London cross-sectional study surveyed adult participants with a confirmed diagnosis of T2D prescribed a minimum of one anti-hyperglycaemic medicine. Surveys were administered face-to-face by community pharmacists using a convenience sampling method based on interactions with pharmacy patients. The survey consisted of questions relating to socio-demographic and clinical data, the SPUR® tool and three previously validated PROMs (BeMQ-General®, MARS-10® and BeMQ-Specific®) as comparators to evaluate factors P, U and R respectively. The Medication Possession Ratio (MPR), a measure of a patient’s pill count in a given time period, was used as an objective comparator of adherence. Pearson’s correlation coefficients (r) were calculated to determine the strength of association between the validated PROMs and SPUR®, with T tests used as a measure of significance (p=&lt;0.05) as an evaluation of validity for SPUR®.

Results

The survey response rate was 21.6% (n=149/690). The modal age range for participants was 60–69 years of age (40.1%, n=60). Participants were predominantly educated to degree level (29.5%, n=44), White (48.3%, n=72) and retired (28.9%, n=43). Overall, 47.6% (n=71) of participants identified as female. Body Mass Index (BMI) data were available for 88.6% (n=132) of the sample with 42.4% (n=56/132) reporting a BMI &gt;30. In ascending order, moderate to strong positive correlations were observed between SPUR® and the comparative PROMs for factors P (r=0.464, p=&lt;0.0001), U (r=0.595, p=&lt;0.0001) and R (r=0.719, p=&lt;0.0001), indicating SPUR® to be a reliable measure of those MA factors. When assessing MA objectively, SPUR® demonstrated the strongest correlation (r=0.281, p=&lt;0.0001) to MPR compared with the validated tools, with MARS-10® as the closest comparator (r=0.266, p=0.001). Despite this, SPUR® did not overestimate MA, 83.8% (n=125) of the sample was identified as adherent based on MPR compared to 53% (n=79) with SPUR®. The latter more closely reflecting HbA1c data which identified 55.4% (n=31/56) as adherent.

Conclusion

Study strengths include the implementation of validated PROMs and two objective MA measures; however, the study sample size was limited. SPUR® has demonstrated its validity against validated PROMs whilst predicting adherence levels without exaggeration, which is often attributed to crude objective measures such as MPR.(2) SPUR® may therefore holistically identify the multiple factors linked to non-adherence, thus supporting the design of individualised interventions.. Such interventions are deemed by the World Health Organisation as potentially more impactful than developing new treatments.(1)

References

1. Eduardo Sabaté (WHO/NMH/CCH). Adherence to long-term therapies: policy for action. World Heal Organ. Published online 2001.

2. Long JA, Wang A, Medvedeva EL, et al. Glucose control and medication adherence among veterans with diabetes and serious mental illness: Does collocation of primary care and mental health care matter? Diabetes Care. Published online 2014. doi:10.2337/dc13-0051

Challenges and recommendations for magnetic hyperthermia characterization measurements

PURPOSE

The localized heating of magnetic nanoparticles (MNPs) via the application of time-varying magnetic fields - a process known as magnetic field hyperthermia (MFH) - can greatly enhance existing options for cancer treatment; but for broad clinical uptake its optimization, reproducibility and safety must be comprehensively proven. As part of this effort, the quantification of MNP heating - characterized by the specific loss power (SLP), measured in W/g, or by the intrinsic loss power (ILP), in Hm²/kg - is frequently reported. However, in SLP/ILP measurements to date, the apparatus, the analysis techniques and the field conditions used by different researchers have varied greatly, leading to questions as to the reproducibility of the measurements.

MATERIALS AND METHODS

An interlaboratory study (across N = 21 European sites) of calorimetry measurements that constitutes a snapshot of the current state-of-the-art within the MFH community has been undertaken. Identical samples of two stable nanoparticle systems were distributed to all participating laboratories. Raw measurement data as well as the results of in-house analysis techniques were collected along with details of the measurement apparatus used. Raw measurement data was further reanalyzed by universal application of the corrected-slope method to examine relative influences of apparatus and results processing.

RESULTS

The data show that although there is very good intralaboratory repeatability, the overall interlaboratory measurement accuracy is poor, with the consolidated ILP data having standard deviations on the mean of ca. ± 30% to ± 40%. There is a strong systematic component to the uncertainties, and a clear rank correlation between the measuring laboratory and the ILP. Both of these are indications of a current lack of normalization in this field. A number of possible sources of systematic uncertainties are identified, and means determined to alleviate or minimize them. However, no single dominant factor was identified, and significant work remains to ascertain and remove the remaining uncertainty sources.

CONCLUSION

We conclude that the study reveals a current lack of harmonization in MFH characterization of MNPs, and highlights the growing need for standardized, quantitative characterization techniques for this emerging medical technology.

A8 DIETARY TRYPTOPHAN MODULATES KYNURENINE AND INDOLE PRODUCTION IN HEALTHY INDIVIDUALS

Background

Tryptophan is an essential amino acid that is transformed by host and gut microbial enzymes into multiple bioactive metabolites that regulate immunity, mood and circadian rhythms. In particular, indoles, produced by gut bacterial metabolism of tryptophan, have recently gained central attention. Indoles are activators of the aryl hydrocarbon receptor (AhR), which is crucial for the maintenance of intestinal homeostasis and immunity. Tryptophan supplementation in fortified foods have been advocated to prevent chronic inflammatory conditions, from autism to chronic inflammation. However, whether dietary tryptophan supplementation affects immune function, tryptophan metabolic pathways and gastrointestinal symptoms in healthy subjects, is unknown.

Aims

To assess whether tryptophan supplementation, in healthy subjects on a low tryptophan diet, induces changes in microbiota-derived metabolites (indoles), host cytokine production or gut symptoms.

Methods

We performed a randomized, double blind, placebo-controlled, crossover study in 20 healthy individuals, between 18 and 75 years old, following a regular diet. Subjects were instructed to start a standardized low tryptophan diet and were randomly assigned to a 3-week tryptophan supplement (3gr/day) or placebo. After a 2-week washout period, subjects were crossed over to the opposite 3-week intervention arm. Self-administered questionnaires (GSRS, DASS21 and HADS) were used to assess gastrointestinal symptoms and mood/anxiety/stress. Stool, urine and blood samples were collected to measure tryptophan metabolites (kynurenine pathway and indoles) and cytokines.

Results

Supplementation of tryptophan was well tolerated and no changes in gastrointestinal symptoms or mood/anxiety were found. Compared with placebo, tryptophan supplementation increased urinary and plasma levels of indoleamine 2,3-dioxygenase (p= 0.002 and p= 0.02, respectively), a key enzyme in the kynurenine pathway, and of several indoles (p= 0.0008 and p= 0.01, respectively), suggestive of activation of microbial and host metabolic pathways. However, there were no measurable changes in the host cytokine production. There was a positive correlation between fecal kynurenine levels and anxiety and depression scores, suggesting that microbial metabolites may impact host behavior in humans.

Conclusions

Dietary tryptophan supplementation in healthy individuals was safe and had a measurable effect on microbial and host metabolism, mainly kynurenine and indole pathways, with known immunomodulatory properties. Although no effects on cytokine production were found, further studies are warranted to investigate tryptophan supplementation in disorders with altered AhR pathway, such as inflammatory bowel disease, metabolic syndrome and celiac disease.

Funding Agencies

None

Abstract 1617: Developing new mouse models of metastatic lung cancer

INTRODUCTION: The focus of this work is to develop new mouse models for metastatic lung cancer. Lung cancer is the leading cause of cancer deaths worldwide and greater than 90% of human cancer deaths are due to metastasis. Metastatic disease in most existing mouse models of lung cancer is typically sporadic and often requires aging mice for several months. These factors limit the usefulness of mouse models for basic and pre-clinical research aimed at effective treatment of metastatic disease.

METHODS AND RESULTS: We have developed a new mouse model of lung cancer and are in the process of developing two additional models. In the first model, we added mutations in Dicer1, an RNAse III enzyme within the microRNA (miRNA) biosynthesis pathway to a mouse model of Kras-driven pulmonary adenocarcinoma. When we combined conditional expression of an oncogenic allele of Kras (KrasG12D), deletion of both alleles of Trp53 and one allele of Dicer1 in Club cells with expression of truncated Dicer1 in alveolar type II cells, we generated mice with metastatic pulmonary adenocarcinoma. In 30% of these mice, metastatic tumors were observed in the lymph nodes within 11 weeks of tumor induction. In a second mouse model, we switched the cell types expressing the various mutations to determine the effects of cell of origin on tumor progression and metastasis. Our preliminary results suggest that adenocarcinoma develops even faster when KrasG12D is expressed and Trp53 and one allele of Dicer1 are deleted in alveolar type II cells. Finally, based on an analysis of human lung cancer genomics data from TCGA, we generated a mouse model with mutations in Zfhx4 and are crossing these mice with our models that express oncogenic KrasG12D, delete expression of Trp53 and one allele of Dicer1 and truncate the second allele of Dicer1 to determine the effects of adding Zfhx4 mutations on progression and metastasis of pulmonary adenocarcinoma.

CONCLUSIONS: Through cell type specific truncation/deletion of Dicer1 we have generated new mouse models that rapidly develop pulmonary adenocarcinomas and metastatic disease. These models have potential for both understanding the basic processes of metastasis and for pre-clinical studies aimed at preventing and/or treating metastatic lung cancer.

Citation Format: Julie Wells, Richard S. Maser, Teresa McGee, Wendy Memishian, Rosalinda Doty, Carol J. Bult. Developing new mouse models of metastatic lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1617.

Identifying Indicators of National Council Licensure Examination for Registered Nurses (NCLEX-RN) Success in Nursing Graduates in Newfoundland & Labrador

In Canada in 2015, the pass rates on the National Council Licensure Examination (NCLEX-RN) were considerably lower than pass rates on the Canadian Registered Nurse Examination (CRNE) causing nurse educators to express concern regarding the NCLEX-RN. The purpose of this study was to examine the relationship between candidate variables (e. g. academic performance, demographics) on their NCLEX-RN outcome (pass/fail). A cross-sectional data linkage design was employed using multiple sources of data on nursing graduates who wrote the NCLEX-RN in 2015, 2016 and 2017 (n = 259). Results showed that fewer questions answered on the NCLEX-RN and higher grades in various nursing courses (e. g. Introduction to Nursing, Statistics) predicted higher odds of passing the NCLEX-RN. To improve pass rates, nurse educators must integrate diverse methods of testing into existing curricula that mimic the NCLEX-RN exam, specifically computer adaptive exams. Further research is needed to determine other possible challenges for countries considering adopting the NCLEX-RN.

Ambroxol as a novel disease-modifying treatment for Parkinson's disease dementia: protocol for a single-centre, randomized, double-blind, placebo-controlled trial

BACKGROUND

Currently there are no disease-modifying treatments for Parkinson's disease dementia (PDD), a condition linked to aggregation of the protein α-synuclein in subcortical and cortical brain areas. One of the leading genetic risk factors for Parkinson's disease is being a carrier in the gene for β-Glucocerebrosidase (GCase; gene name GBA1). Studies in cell culture and animal models have shown that raising the levels of GCase can decrease levels of α-synuclein. Ambroxol is a pharmacological chaperone for GCase and is able to raise the levels of GCase and could therefore be a disease-modifying treatment for PDD. The aims of this trial are to determine if Ambroxol is safe and well-tolerated by individuals with PDD and if Ambroxol affects cognitive, biochemical, and neuroimaging measures.

METHODS

This is a phase II, single-centre, double-blind, randomized placebo-controlled trial involving 75 individuals with mild to moderate PDD. Participants will be randomized into Ambroxol high-dose (1050 mg/day), low-dose (525 mg/day), or placebo treatment arms. Assessments will be undertaken at baseline, 6-months, and 12-months follow up times. Primary outcome measures will be the Alzheimer's disease Assessment Scale-cognitive subscale (ADAS-Cog) and the ADCS Clinician's Global Impression of Change (CGIC). Secondary measures will include the Parkinson's disease Cognitive Rating Scale, Clinical Dementia Rating, Trail Making Test, Stroop Test, Unified Parkinson's disease Rating Scale, Purdue Pegboard, Timed Up and Go, and gait kinematics. Markers of neurodegeneration will include MRI and CSF measures. Pharmacokinetics and pharmacodynamics of Ambroxol will be examined through plasma levels during dose titration phase and evaluation of GCase activity in lymphocytes.

DISCUSSION

If found effective and safe, Ambroxol will be one of the first disease-modifying treatments for PDD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02914366, 26 Sep 2016/retrospectively registered.

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.

Thomson scattering systems on C-2W field-reversed configuration plasma experiment

TAE Technologies' newly constructed C-2W experiment aims to improve the ion and electron temperatures in a sustained field-reversed configuration plasma. A suite of Thomson scattering systems has been designed and constructed for electron temperature and density profile measurements. The systems are designed for electron densities of 1 × 10¹² cm^-3 to 2 × 10¹⁴ cm^-3 and temperature ranges from 10 eV to 2 keV. The central system will provide profile measurements of T_e and n_e at 16 radial locations from r = -9 cm to r = 64 cm with a temporal resolution of 20 kHz for 4 pulses or 1 kHz for 30 pulses. The jet system will provide profile measurements of T_e and n_e at 5 radial locations in the open field region from r = -5 cm to r = 15 cm with a temporal resolution of 100 Hz. The central system and its components have been characterized, calibrated, installed, and commissioned. A maximum-likelihood algorithm has been applied for data processing and analysis.

Development of a three-wave far-infrared laser interferometry and polarimetry diagnostic system for the C-2W field-reversed configuration plasmas

Great advancements in modern field-reversed configuration (FRC) experiments motivated the development of a 14-chord three-wave far infrared (FIR) laser interferometry and polarimetry diagnostic system, which can provide simultaneous high temporal resolution measurements of density and Faraday rotation profiles with high accuracy. The unique challenges facing FIR diagnostics in high beta FRC plasmas are the extremely small (<0.5°) Faraday rotation angles, and severe laser beam refraction effects due to high density gradient and choice of long wavelength. The diagnostic system design and development are described with methods to overcome the challenges, and initial experimental data are also presented.

Presumed tuberculosis-associated uveitis: rising incidence and widening criteria for diagnosis in a non-endemic area

PurposeTo assess the incidence, clinical ocular involvement and effectiveness of anti-tuberculous treatment in patients with chronic uveitis presumed to be associated with tuberculosis in a non-endemic community.Patients and methodsRetrospective case series of patients with uveitis and evidence of tuberculosis, with no other identified cause of uveitis, who underwent a 6-month course of standard anti-tuberculosis treatment between 2008 and 2015. The response to treatment was assessed at 6 and 12 months after initiation of treatment.ResultsForty-eight patients were included of whom 36 (75%) were born outside the United Kingdom. Only five had concurrent active pulmonary or nodal tuberculosis. There were 85 affected eyes, including 25 with granulomatous anterior uveitis, 32 with retinal vasculitis (occlusive in 21), and 20 with multifocal choroiditis or serpiginous-like retinochoroiditis. Gamma-interferon testing was positive in 95%. Complete resolution at end point was seen in only 60%, but a further 19% were inflammation-free on topical steroid only. Resolution was lower (50%) in those with panuveitis compared to other anatomical types (75%). Sixty-four eyes (75%) had a LogMAR visual acuity of 0.1 or better at the end of the study.ConclusionsThe incidence of presumed tuberculosis-associated uveitis (TBU) has almost quadrupled in this region. The efficacy of treatment has not been enhanced by the introduction of gamma-interferon testing to support diagnosis. Some patients may require more prolonged antibiotic therapy to ensure quiescence, but chronic non-infective anterior uveitis may in any case follow treated TBU.

Study protocol: An investigation of mother-infant signalling during breastfeeding using a randomised trial to test the effectiveness of breastfeeding relaxation therapy on maternal psychological state, breast milk production and infant behaviour and growth

Background

The physiological and psychological signalling between mother and infant during lactation is one of the prominent mother-infant factors that may influence breastfeeding outcomes. The infant can ‘signal’ his needs through vocalisation, and the mother can respond by allowing or restricting nipple access, which might alter the breast milk composition or volume. This may lead to parent-offspring conflict during the lactation period. Challenging infant behaviour has also been associated with maternal psychological distress, which might affect breastfeeding performance. Most attempts to improve breastfeeding rates focus on providing additional support, yet many aspects of the breastfeeding process are poorly understood. Thus, our objective is to investigate mother-infant signalling during breastfeeding by manipulating maternal psychological state using a relaxation therapy intervention. The study will test the hypothesis that mothers who listen to the therapy will be more relaxed/less stressed and this will favourably alter breast milk composition and/or affect milk volume and hence influence infant outcomes.

Methods

A randomised controlled trial will be conducted in first-time breastfeeding mothers and their new-born infants. Pregnant mothers will be recruited at antenatal clinics in Selangor, Malaysia, and four home visits will be carried out at 2, 6, 12 and 14 weeks postnatally. Participants will be randomised into a control and an intervention group in the early post-partum period. Mothers from the intervention group will be asked to listen daily to an audio recording with relaxation therapy during breastfeeding. Maternal psychological state, breastfeeding practices and infant behaviour will be assessed using validated questionnaires. Milk volume will be measured using stable isotopes. Breast milk samples will be collected to measure macronutrient content and hormone levels. Anthropometric measurements (weight, length and head circumference) will be performed during all home visits, including body composition at week 14.

Discussion

The main outcomes will be the effect of the intervention on maternal psychological state, milk production, cortisol levels, and infant behaviour and growth. Secondary outcomes will be associations between breast milk composition and infant appetite and growth. This study aims to provide a greater understanding of maternal-infant factors which influence breastfeeding outcomes and which may be useful targets for future interventions.

Trial registration

ClinicalTrials.gov identifier: NCT01971216.

Dark Matter Search Results from the PICO-60 C_{3}F_{8} Bubble Chamber

New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C_{3}F_{8} located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C_{3}F_{8} exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10^{-41}  cm^{2} for a 30-GeV c^{-2} WIMP, more than 1 order of magnitude improvement from previous PICO results.

Phase I study of oncolytic virus (OV) MG1 maraba/MAGE-A3 (MG1MA3), with and without transgenic MAGE-A3 adenovirus vaccine (AdMA3) in incurable advanced/metastatic MAGE-A3-expressing solid tumours: CCTG IND.214

e14637

Background: OVs display oncolytic activity and boost adaptive cell immunity. MG1MA3 is a Maraba virus modified to express tumour antigen MAGE-A3. MG1MA3, both alone and after immune priming with a MAGE-A3 modified adenovirus (AdMA3) may trigger anti-tumour T-cell responses. Methods: N = 41 patients (pts) with MAGE-A3 expressing solid tumours were evaluated in 3 groups (A) Dose escalation of MG1MA3 iv d1+4, q8w (n = 9); (B) Single fixed dose AdMA3 1e10 pfu IM d1 (n = 6); (C) AdMA3 priming d(-14) followed by dose escalated MG1MA3 (d1+4, q8w) (n = 25). Arm A and C had a 3+3 design. Pre + post treatment blood and tissue biopsies were evaluated for viral and immune markers. Endpoints included MTD/MFD, RP2DL, safety, tolerability, pharmacokinetics, viral delivery and replication. Results: Dose limiting toxicities (hypoxia/dyspnea, vomiting, headache) occurred in 4 pts (2 each Arm A +C). RP2DL for arm C was AdMA3 1e10 pfu IM d(-14) then MG1MA3 1e11 pfu iv d1+4. Common treatment related toxicities on Arm C occurring hours to a few days after MG1MA3 included diarrhea, nausea, vomiting, anorexia, chills, fatigue, fever, flu-like symptoms, hypophosphatemia, headache, and hypotension. Preliminary tumour gene expression results reveal induction of pro-inflammatory genes, including chemokines (CCL2, CCL5, CX3CL1, CXCL10), acute phase response proteins (IL-6, TNF), antigen presenting cell (APC) activation markers (CD80, HLA-A, HLA-B), markers of APC and Natural Killer cell infiltration (CD56, CD68, TLR3), as well as a co-incident decrease in the suppressive cytokine TGF-β. MG1MA3 replication was observed in some pts, inferred by detection of circulating genomes on days 4, 8 and 15 after clearance of the input dose. Induction of anti-tumour immune responses (CD8 T cells and antibodies vs MAGE-A3) was demonstrated in 3 of 6 Arm C pts evaluated to date. In one patient, over 1% of circulating CD8 T cells were directed against MAGE-A3. Conclusions: AdMA3 prime followed by MG1MA3 OV boost is feasible with a defined RP2DL, and capable of inducing potent anti-tumour immune response. Alternate schedules will be evaluated. Clinical trial information: NCT02285816.

Adjuvant sunitinib following chemoradiotherapy and surgery for locally advanced esophageal cancer: a phase II trial

The prognosis for locally advanced esophageal cancer is poor despite the use of trimodality therapy. In this phase II study, we report the feasibility, tolerability and efficacy of adjuvant sunitinib. Included were patients with stage IIa, IIB or III cancer of the thoracic esophagus or gastroesophageal junction. Neoadjuvant therapy involved Irinotecan (65 mg/m² ) + Cisplatin (30 mg/m² ) on weeks 1 and 2, 4 and 5, 7 and 8 with concurrent radiation (50Gy/25 fractions) on weeks 4-8. Sunitinib was commenced 4-13 weeks after surgery and continued for one year. Sixty-one patients were included in the final analysis, 36 patients commenced adjuvant sunitinib. Fourteen patients discontinued sunitinib due to disease recurrence (39%) within the 12-month period, 12 (33%) discontinued due to toxicity, and 3 (8%) requested cessation of therapy. In the overall population, median survival was 26 months with a 2 and 3-year survival rate of 52% and 35%, respectively. The median survival for the 36 patients treated with sunitinib was 35 months and 2-year survival probability of 68%. In a historical control, a prior phase II study with the same trimodality therapy (n = 43), median survival was 36 months, with a 2-year survival of 67%. Initiation of adjuvant sunitinib is feasible, but poorly tolerated, with no signal of additional benefit over trimodality therapy for locally advanced esophageal cancer.

Using a Design Approach to Assist Large-Scale Organizational Change

A team of practitioners, university researchers, and health care policy makers has been working to develop and apply “design sciences” thinking within the challenging context of a national system aiming to bring about a “revolution in health care.” As members of that team, the authors share that thinking and early findings with those interested in the concept, theory, and practice of design as an approach to large-scale organizational change. The article builds on what to date has been a somewhat abstract debate around the design sciences, its aim being to forge stronger links between the concept and the practice of design. Using empirical data from the English National Health Service as a case study, the article seeks to demonstrate how design sciences may first, expand our thinking around organizational theory and practice and second, offer organization development some new methods, approaches, and processes around the “doing” of large-scale change.

Systematic chemical and molecular profiling of MLL-rearranged infant acute lymphoblastic leukemia reveals efficacy of romidepsin

To address the poor prognosis of mixed lineage leukemia (MLL)-rearranged infant acute lymphoblastic leukemia (iALL), we generated a panel of cell lines from primary patient samples and investigated cytotoxic responses to contemporary and novel Food and Drug Administration-approved chemotherapeutics. To characterize representation of primary disease within cell lines, molecular features were compared using RNA-sequencing and cytogenetics. High-throughput screening revealed variable efficacy of currently used drugs, however identified consistent efficacy of three novel drug classes: proteasome inhibitors, histone deacetylase inhibitors and cyclin-dependent kinase inhibitors. Gene expression of drug targets was highly reproducible comparing iALL cell lines to matched primary specimens. Histone deacetylase inhibitors, including romidepsin (ROM), enhanced the activity of a key component of iALL therapy, cytarabine (ARAC) in vitro and combined administration of ROM and ARAC to xenografted mice further reduced leukemia burden. Molecular studies showed that ROM reduces expression of cytidine deaminase, an enzyme involved in ARAC deactivation, and enhances the DNA damage-response to ARAC. In conclusion, we present a valuable resource for drug discovery, including the first systematic analysis of transcriptome reproducibility in vitro, and have identified ROM as a promising therapeutic for MLL-rearranged iALL.

A Phase I study of olaparib and irinotecan in patients with colorectal cancer: Canadian Cancer Trials Group IND 187

Background Olaparib is an orally available inhibitor of PARP-1. In pre-clinical studies, olaparib was shown to potentiate anti-tumor effects of irinotecan in colon cancer cell lines. This phase I study was conducted to evaluate the safety and tolerability of olaparib in combination with irinotecan. Patients and Methods Patients with advanced colorectal cancer whose disease progressed after at least one systemic therapy regimen were enrolled. Dose escalation and de-escalation were based on toxicity assessment. Pharmacokinetic samples were collected in Cycle 1 for olaparib, irinotecan and SN-38. Results Twenty-five patients were enrolled, 11 patients on a schedule of continuous olaparib and irinotecan every 3 weeks (Part A) and 14 patients on a schedule of intermittent olaparib and irinotecan every 2 weeks (Part B). Continuous olaparib administration was associated with higher than expected toxicities and was not considered to be tolerable. Intermittent olaparib administration was better tolerated, and the recommended phase 2 doses were olaparib 50 mg p.o twice daily days 1-5 and irinotecan 125 mg/m(2) i.v. every 2 weeks. Common toxicities included fatigue, anorexia, diarrhea, nausea, vomiting, neutropenia, thrombocytopenia and abdominal pain. Nine patients had stable disease as the best response, 2 from Part A (3 and 9 months respectively), and 7 from Part B (median duration: 7.4 months; range: 4 to 13 months). There was no pharmacokinetic interaction between olaparib and irinotecan. Conclusions Olaparib can be combined with irinotecan if administered intermittently. Both olaparib and irinotecan required significant dose reductions. The lack of anti-tumor efficacy observed in this trial makes this combination of little interest for further clinical development. Trial Registration ID NCT00535353.

Defining Rehabilitation Success in Older Adults with Dementia--Results from an Inpatient Geriatric Rehabilitation Unit

OBJECTIVE

To quantify the magnitude of functional recovery in older adults with and without dementia admitted to an inpatient geriatric rehabilitation program by measuring change in measures of global physical function and physical therapy treatment outcomes.

DESIGN

Retrospective cohort study.

SETTING

Rehabilitation academic hospital.

PARTICIPANTS

Consecutive subjects, with (N=65, age 81.9±6.0 y) and without (N=157, age 82.8±7.2 y) a dementia diagnosis, had assessment data at admission and discharge from inpatient geriatric rehabilitation unit.

INTERVENTIONS

Not applicable.

MEASUREMENTS

The Functional Independence Measure (FIM) was used to estimate level of independence on activities of daily living. The Berg Balance Scale (BBS), Timed Up and Go Test (TUG) and 2 Minute Walk Test (2MWT) were used to estimate functional mobility and endurance. The FIM (total, motor subscale, cognitive subscale scores) were used to calculate rehabilitation efficacy and efficiency scores.

RESULTS

After controlling for confounding, there was no group difference for gains on the BBS, TUG, 2MWT; there was no group difference on rehabilitation efficacy and efficiency values based on the FIM motor subscale. The magnitude of the rehabilitation gain using the total FIM score was statistically different between groups, people with dementia having smaller gains.

CONCLUSION

Older adults with a diagnosis of dementia are capable of making motor function recovery during inpatient sub-acute rehabilitation comparable to their peers without a dementia diagnosis. The metric used to evaluate functional recovery influences the determination of rehabilitation success between groups. Rehabilitation success should be defined among people with a dementia diagnosis by a change in the motor subscale of the FIM, rather than the total FIM score or the gain relative to the maximal FIM score.