Sustaining attention in affective contexts during adolescence: age-related differences and association with elevated symptoms of depression and anxiety

Sustained attention, a key cognitive skill that improves during childhood and adolescence, tends to be worse in some emotional and behavioural disorders. Sustained attention is typically studied in non-affective task contexts; here, we used a novel task to index performance in affective versus neutral contexts across adolescence (N = 465; ages 11-18). We asked whether: (i) performance would be worse in negative versus neutral task contexts; (ii) performance would improve with age; (iii) affective interference would be greater in younger adolescents; (iv) adolescents at risk for depression and higher in anxiety would show overall worse performance; and (v) would show differential performance in negative contexts. Results indicated that participants performed more poorly in negative contexts and showed age-related performance improvements. Those at risk of depression performed more poorly than those at lower risk. However, there was no difference between groups as a result of affective context. For anxiety there was no difference in performance as a function of severity. However, those with higher anxiety showed less variance in their reaction times to negative stimuli than those with lower anxiety. One interpretation is that moderate levels of emotional arousal associated with anxiety make individuals less susceptible to the distracting effects of negative stimuli.

Acute Toxicity of Hypofractionated and Conventionally Fractionated (Chemo)Radiotherapy Regimens for Bladder Cancer: An Exploratory Analysis from the RAIDER Trial

AIMS

Adding concurrent (chemo)therapy to radiotherapy improves outcomes for muscle-invasive bladder cancer patients. A recent meta-analysis showed superior invasive locoregional disease control for a hypofractionated 55 Gy in 20 fractions schedule compared with 64 Gy in 32 fractions. In the RAIDER clinical trial, patients undergoing 20 or 32 fractions of radical radiotherapy were randomised (1:1:2) to standard radiotherapy or to standard-dose or escalated-dose adaptive radiotherapy. Neoadjuvant chemotherapy and concomitant therapy were permitted. We report exploratory analyses of acute toxicity by concomitant therapy-fractionation schedule combination.

MATERIALS AND METHODS

Participants had unifocal bladder urothelial carcinoma staged T2-T4a N0 M0. Acute toxicity was assessed (Common Terminology Criteria for Adverse Events) weekly during radiotherapy and at 10 weeks after the start of treatment. Within each fractionation cohort, non-randomised comparisons of the proportion of patients reporting treatment emergent grade 2 or worse genitourinary, gastrointestinal or other adverse events at any point in the acute period were carried out using Fisher's exact tests.

RESULTS

Between September 2015 and April 2020, 345 (163 receiving 20 fractions; 182 receiving 32 fractions) patients were recruited from 46 centres. The median age was 73 years; 49% received neoadjuvant chemotherapy; 71% received concomitant therapy, with 5-fluorouracil/mitomycin C most commonly used: 44/114 (39%) receiving 20 fractions; 94/130 (72%) receiving 32 fractions. The acute grade 2+ gastrointestinal toxicity rate was higher in those receiving concomitant therapy compared with radiotherapy alone in the 20-fraction cohort [54/111 (49%) versus 7/49 (14%), P < 0.001] but not in the 32-fraction cohort (P = 0.355). Grade 2+ gastrointestinal toxicity was highest for gemcitabine, with evidence of significant differences across therapies in the 32-fraction cohort (P = 0.006), with a similar pattern but no significant differences in the 20-fraction cohort (P = 0.099). There was no evidence of differences in grade 2+ genitourinary toxicity between concomitant therapies in either the 20- or 32-fraction cohorts.

CONCLUSION

Grade 2+ acute adverse events are common. The toxicity profile varied by type of concomitant therapy; the gastrointestinal toxicity rate seemed to be higher in patients receiving gemcitabine.

Intracranial Cannula Implantation for Serial Locoregional Chimeric Antigen Receptor (CAR) T Cell Infusions in Mice

Pediatric CNS tumors are responsible for the majority of cancer-related deaths in children and have poor prognoses, despite advancements in chemotherapy and radiotherapy. As many tumors lack efficacious treatments, there is a crucial need to develop more promising therapeutic options, such as immunotherapies; the use of chimeric antigen receptor (CAR) T cell therapy directed against CNS tumors is of particular interest. Cell surface targets such as B7-H3, IL13RA2, and the disialoganglioside GD2 are highly expressed on the surface of several pediatric and adult CNS tumors, raising the opportunity to use CAR T cell therapy against these and other surface targets. To evaluate the repeated locoregional delivery of CAR T cells in preclinical murine models, an indwelling catheter system that recapitulates indwelling catheters currently being used in human clinical trials was established. Unlike stereotactic delivery, the indwelling catheter system allows for repeated dosing without the use of multiple surgeries. This protocol describes the intratumoral placement of a fixed guide cannula that has been used to successfully test serial CAR T cell infusions in orthotopic murine models of pediatric brain tumors. Following orthotopic injection and engraftment of the tumor cells in mice, intratumoral placement of a fixed guide cannula is completed on a stereotactic apparatus and secured with screws and acrylic resin. Treatment cannulas are then inserted through the fixed guide cannula for repeated CAR T cell delivery. Stereotactic placement of the guide cannula can be adjusted to deliver CAR T cells directly into the lateral ventricle or other locations in the brain. This platform offers a reliable mechanism for the preclinical testing of repeated intracranial infusions of CAR T cells and other novel therapeutics for these devastating pediatric tumors.

Patterns of Failure After Stereotactic Body Radiotherapy to Sacral Metastases

AIMS

Stereotactic body radiotherapy (SBRT) is increasingly used to treat sacral metastases. We analysed our centre's local relapse rates and patterns of failure after sacral SBRT and assessed whether using the consensus contouring recommendation (CCR) may have prevented local relapse.

MATERIALS AND METHODS

We conducted a single-centre retrospective review of patients treated with sacral SBRT between February 2012 and December 2021. The cumulative incidence of local relapse, patterns of failure and overall survival were determined. Two investigators reviewed planning computed tomography scans and imaging at relapse to determine if local relapse was potentially preventable with a larger CCR-derived radiotherapy field.

RESULTS

In total, 34 patients received sacral SBRT, with doses ranging from 24 to 40 Gy over three to five fractions. The most frequently used schedule was 30 Gy in three fractions. Common primaries treated included prostate (n = 16), breast (n = 6), lung (n = 3) and renal (n = 3) cancers. The median follow-up was 20 months (interquartile range 13-55 months). The cumulative incidence of local relapse (4/34) was 2.9% (95% confidence interval 0.2-13.2), 6.3% (95% confidence interval 1.1-18.5) and 16.8% (95% confidence interval 4.7-35.4) at 6 months, 1 year and 2 years, respectively. The patterns of failure were local-only (1/34), local and distant (3/34) and distant relapse (10/34). The overall survival was 96.7% (95% confidence interval 90.5-100) and 90.6% (95% confidence interval 78.6-100) at 1 and 2 years, respectively. For prostate/breast primaries, the cumulative incidence of local relapse was 4.5% (95% confidence interval 0.3-19.4), 4.5% (95% confidence interval 0.3-19.4) and 12.5% (95% confidence interval 1.7-34.8) at 6 months, 1 and 2 years, respectively. Twenty-nine cases (85.3%) deviated from the CCR. Sacral relapse was potentially preventable if the CCR was used in one patient (2.9% of the whole cohort and 25% of the relapsed cohort).

DISCUSSION

We have shown excellent local control rates with sacral SBRT, which was largely planned with a margin expansion approach.

EXTH-85. TARGETING CLAUDIN 6 WITH CAR T CELL THERAPY FOR ATYPICAL TERATOID/RHABDOID TUMOR

Atypical teratoid/rhabdoid tumor (ATRT) is an aggressive brain tumor that predominantly affects young children and has an average 5-year survival under 50%. Novel, targeted therapies are desperately needed. Claudin 6 (CLDN6) is a tight junction protein present during development and expressed in up to 70% of ATRT specimens but not in normal tissue, making it a promising immunotherapeutic target. CLDN6-targeted chimeric antigen receptor (CAR) T cells in combination with a CAR T cell–amplifying mRNA vaccine have demonstrated antitumor activity against other CLDN6-expressing cancers in pre-clinical and phase I adult trial (NCT04503278; Haanen J et al AACR, 2022). To assess the effectiveness of CLDN6-targeted CAR T cells against ATRT, we utilized a second-generation mRNA CAR with a 4-1BB costimulatory domain and single-chain variable fragment against CLDN6 (Reinhard et al, 2020). Patient-derived ATRT specimens were assessed by RNAseq for CLDN6 expression (mean FPKM= 11.4) and by immunohistochemistry (positive staining in 53% of specimens). Tumor-derived cell lines were validated for CLDN6 expression by flow cytometry. Co-culture of CLDN6-directed mRNA CAR T cells with ATRT cell line 7316-2187 resulted in tumor-specific cytotoxicity compared to CD19-directed control CAR T cells (92% versus 15% at 10:1, p&lt; 0.0001; 86% versus 0% at 5:1, p&lt; 0.0001). Similar results were seen with ATRT cell line 7316-2141 (75% versus 7% at 10:1, p&lt; 0.0001; 53% versus 0% at 5:1, p&lt; 0.0001). Both CLDN6- and CD19-directed CAR T cells showed no cytotoxicity against CLDN6-negative cell line 7316-4149. Patient-derived xenograft models were also created through intracranial injection of multiple ATRT patient cell lines, and ongoing work will evaluate locoregional administration of CLDN6-directed CAR T cells in orthotopic xenograft models to test in vivo efficacy. This work highlights the potential for targeting CLDN6 via CAR T cell therapy in patients with ATRT as a novel therapeutic strategy for these devastating tumors.

Development of GPC2-directed chimeric antigen receptors using mRNA for pediatric brain tumors

BACKGROUND

Pediatric brain tumors are the leading cause of cancer death in children with an urgent need for innovative therapies. Glypican 2 (GPC2) is a cell surface oncoprotein expressed in neuroblastoma for which targeted immunotherapies have been developed. This work aimed to characterize GPC2 expression in pediatric brain tumors and develop an mRNA CAR T cell approach against this target.

METHODS

We investigated GPC2 expression across a cohort of primary pediatric brain tumor samples and cell lines using RNA sequencing, immunohistochemistry, and flow cytometry. To target GPC2 in the brain with adoptive cellular therapies and mitigate potential inflammatory neurotoxicity, we used optimized mRNA to create transient chimeric antigen receptor (CAR) T cells. We developed four mRNA CAR T cell constructs using the highly GPC2-specific fully human D3 single chain variable fragment for preclinical testing.

RESULTS

We identified high GPC2 expression across multiple pediatric brain tumor types including medulloblastomas, embryonal tumors with multilayered rosettes, other central nervous system embryonal tumors, as well as definable subsets of highly malignant gliomas. We next validated and prioritized CAR configurations using in vitro cytotoxicity assays with GPC2-expressing neuroblastoma cells, where the light-to-heavy single chain variable fragment configurations proved to be superior. We expanded the testing of the two most potent GPC2-directed CAR constructs to GPC2-expressing medulloblastoma and high-grade glioma cell lines, showing significant GPC2-specific cell death in multiple models. Finally, biweekly locoregional delivery of 2-4 million GPC2-directed mRNA CAR T cells induced significant tumor regression in an orthotopic medulloblastoma model and significantly prolonged survival in an aggressive orthotopic thalamic diffuse midline glioma xenograft model. No GPC2-directed CAR T cell related neurologic or systemic toxicity was observed.

CONCLUSION

Taken together, these data show that GPC2 is a highly differentially expressed cell surface protein on multiple malignant pediatric brain tumors that can be targeted safely with local delivery of mRNA CAR T cells, laying the framework for the clinical translation of GPC2-directed immunotherapies for pediatric brain tumors.

The impact of mindfulness training in early adolescence on affective executive control, and on later mental health during the COVID-19 pandemic: a randomised controlled trial

BACKGROUND

Previous research suggests that mindfulness training (MT) appears effective at improving mental health in young people. MT is proposed to work through improving executive control in affectively laden contexts. However, it is unclear whether MT improves such control in young people. MT appears to mitigate mental health difficulties during periods of stress, but any mitigating effects against COVID-related difficulties remain unexamined.

OBJECTIVE

To evaluate whether MT (intervention) versus psychoeducation (Psy-Ed; control), implemented in after-school classes: (1) Improves affective executive control; and/or (2) Mitigates negative mental health impacts from the COVID-19 pandemic.

METHODS

A parallel randomised controlled trial (RCT) was conducted (Registration: https://osf.io/d6y9q/; Funding: Wellcome (WT104908/Z/14/Z, WT107496/Z/15/Z)). 460 students aged 11-16 years were recruited and randomised 1:1 to either MT (N=235) or Psy-Ed (N=225) and assessed preintervention and postintervention on experimental tasks and self-report inventories of affective executive control. The RCT was then extended to evaluate protective functions of MT on mental health assessed after the first UK COVID-19 lockdown.

FINDINGS

Results provided no evidence that the version of MT used here improved affective executive control after training or mitigated negative consequences on mental health of the COVID-19 pandemic relative to Psy-Ed. No adverse events were reported.

CONCLUSIONS

There is no evidence that MT improves affective control or downstream mental health of young people during stressful periods.

CLINICAL IMPLICATIONS

We need to identify interventions that can enhance affective control and thereby young people's mental health.

MODL-30. Children’s Brain Tumor Network preclinical tumor models development and sharing platform: collaborative model empowering pediatric brain tumor discovery and global research

Pediatric brain tumor preclinical field suffered for years from the lack of in vitro and in vivo models. With the explosion of novel therapy approaches for solid and brain tumors, including the immunotherapies it is essential to maximize the access to preclinical models for preclinical specificity, efficacy as well and safety. One of the many ways the Children’s Brain Tumor Network (CBTN) accelerates the pediatric brain tumor research and discovery is through support of the tumor model development program. This program focuses on the generation, characterization, and distribution of diverse models to investigators worldwide provided free of charge. Here we present the resource platform with over 150 cell lines, organoids and patient derived xenografts (PDX) developed and/or propagated at D3b at CHOP on behalf of CBTN. This platform maximizes the tumor tissue use to generate a combination of cell line, organoids and/or xenograft models grown in animals. In recent years, consortium supported over 40 requests for cells lines used in basic biology and translational studies internationally. Current efforts focusing also on supporting large-scale data generation and testing through its collaborative model (Childhood Cancer Model Atlas, Procan, National Center for Advancing Translational Sciences) to maximize the molecular information available for each tumor model essential in preclinical screenings. The generated and returned to consortia data are bound with the deidentified patient clinical information and genomic data and freely available through Kid’s First Data, Cavatica and PedcBio portals. These efforts have already attracted interest from pharma stakeholders previously not observed in pediatric brain environment. This open-source repository model is an example of a unique research partnership supported by patients and their families and built with one mission to bring fast change to kids suffering from brain tumors.

IMMU-22. Safely targeting GD2 in thalamic diffuse midline glioma with mRNA CAR T cells

Chimeric antigen receptor (CAR) T cells targeting the disialoganglioside GD2 have shown promise as a therapeutic for diffuse midline glioma (DMG). However, prior studies raised significant concerns of neurotoxicity and fatality when using virally transduced CAR T cells against midline thalamic tumors. Building upon our prior work optimizing mRNA for use in CAR T cells (Hum Gen Ther, 2019), we hypothesized repeated dosing of transient GD2-directed mRNA CAR T cells could be employed for safe and effective treatment of thalamic DMG. GD2-directed CAR T cells were created using mRNA encoding the 14G2a single chain variable fragment paired with 41BB and CD3-zeta co-stimulatory domains and transfected into human T cells. CAR T cells were tested against the murine thalamic DMG xenograft 7316-6349 via locoregional delivery with an indwelling infusion catheter for repeated dosing. The previously reported fatal neurotoxicity observed in mice using lentiviral CAR T cells could be recapitulated with aggressive dosing. Four doses of 5 x 10⁶ mRNA CAR T cells delivered intratumorally twice a week resulted in median overall survival of 9 days for GD2-treated mice compared to >30 days for CD19-treated controls (p<0.01). This toxicity could be avoided by decreasing the dose and timing of infusions to 2 x 10⁶ mRNA CAR T cells delivered once weekly. Bioluminescent imaging showed regression of tumor in GD2-treated mice compared to CD19-treated controls (radiance fold change -3 x10⁶ versus +20x10⁶ p/sec/cm2/sr, p<0.01). Notably, non-tumor bearing mice treated with GD2-directed CAR T cells quickly developed fatal neurotoxicity within 14 days, suggesting on-target/off-tumor effect of the CAR T cells and a very narrow therapeutic window in the brain. These data highlight the utility of titratable mRNA-based CAR T cell therapy for CNS tumors and establish GD2-directed mRNA CAR T cells as a safe and effective method for treating thalamic DMG.

Effect of bovine feeding system (pasture or concentrate) on the oxidative and sensory shelf life of whole milk powder

Correlating volatile compounds with the sensory attributes of whole milk powder (WMP) is fundamental for appreciating the effect of lipid oxidation (LO) on sensory perception. LO compounds can adversely affect the sensory perception of WMP by imparting rancid, metallic, and painty notes. Whole milk powders derived from milk produced by cows maintained on a pasture diet (grass and grass-clover mix) versus a nonpasture diet [total mixed ration (TMR); concentrates and silage] were stored at room temperature 21°C (ambient storage) and 37°C (accelerated storage) and analyzed for volatile compounds and sensory attributes every 2 mo for a total of 6 mo. Thirteen volatile compounds originating from LO were chosen to track the volatile profile of the WMP during storage. Color, composition, total fatty acid, and free fatty acid profiling were also carried out. Significant variations in the concentrations of 14 fatty acids were observed in WMP based on diet. Concentrations of free fatty acids increased in all sample types during storage. Similar trends in sensory attributes were observed with an increase in painty attributes, corresponding to an increase in hexanal. Buttery/toffee attributes were found to be more closely correlated with TMR WMP. Those WMP derived from pasture diets were found to be more susceptible to LO from a volatile perspective, particularly in relation to aldehyde development, which is likely due to increased concentrations of conjugated linoleic acid and α-linolenic acid found in these samples.

IMMU-16. TARGETING GLYPICAN 2 (GPC2) ON PEDIATRIC MALIGNANT BRAIN TUMORS WITH MRNA CAR T CELLS

Glypican 2 (GPC2) is a cell-surface oncoprotein initially identified in neuroblastoma, retinoblastoma, and medulloblastoma as an ideal target for immunotherapy (Cancer Cell, 2017). Here we evaluated GPC2 expression across the spectrum of pediatric brain tumors using RNA sequencing from specimens in the Children’s Brain Tumor Network (CBTN). High GPC2 expression, defined as >10 FPKM, was found in 100% of embryonal tumors with multilayered rosettes (ETMRs) (n=6), 95% of medulloblastomas (n=122), 86% of other embryonal tumors (n=21), 50% of choroid plexus carcinomas (n=4), 42% of high grade gliomas (HGG) (n=117), and 37% of diffuse midline gliomas (DMG) (n=65). Within medulloblastoma subtypes, group 4 tumors had the highest expression, and within the HGG tumor cohort H3.3 G34 mutated gliomas had the highest GPC2 expression. High GPC2 protein expression was validated with medulloblastoma and HGG/DMG primary tumors and cell lines using IHC, Western blot, and flow cytometry. We next developed two potent CAR T cell constructs using the D3 specific scFv directed against GPC2 for testing in brain tumor models. GPC2-directed CAR T cells were tested in vitro against medulloblastoma and HGG cells lines, and in vivo using two patient-derived medulloblastoma xenograft models: Rcmb28 (group 3) and 7316-4509 (group 4). GPC2-directed mRNA CAR T cells induced significant GPC2-specific cell death in medulloblastoma and HGG cellular models with concomitant T cell degranulation compared to CD19-directed mRNA CAR T cells. In vivo, GPC2-directed mRNA CAR T cells delivered locoregionally induced significant tumor regression measured by bioluminescence after 4–6 intratumoral infusions of 4 x 10⁶ CAR T cells (p<0.0001 for Rcmb28, p<0.05 for 7316-4509). No GPC2-directed CAR T cell related toxicity was observed. GPC2 is a highly differentially expressed cell surface protein on multiple malignant pediatric brain tumors that can be targeted safely with local delivery of mRNA CAR T cells.

IMMU-17. USE OF MRNA FOR SAFE AND EFFECTIVE GD2-DIRECTED CAR T CELLS TO TREAT DIFFUSE MIDLINE GLIOMAS

Chimeric antigen receptor (CAR) T cells targeting the disialoganglioside GD2 have garnered interest as an effective therapeutic for treating diffuse midline glioma (DMG). However, prior studies raised significant concerns of neurotoxicity and fatality when using virally transduced CAR T cells against these midline tumors. Building upon our prior work optimizing mRNA for use in CAR T cells (Hum Gen Ther, 2019), we hypothesized transient GD2-directed mRNA CAR T cells could be successfully employed for safe and effective treatment of DMG. GD2-directed CAR T cells were created using mRNA encoding the 14G2a single chain variable fragment paired with 41BB and CD3-zeta co-stimulatory domains and transfected into human T cells. GD2-directed CAR T cells were tested against a panel of DMG cell lines and two murine xenograft models of DMG: 7316-6349 and SU-DIPG13P*. In all DMG cellular models, GD2-directed mRNA CAR T cells induced significant tumor cell death compared to CD19-directed mRNA CAR T cell controls. In vivo, mRNA CAR T cells were delivered locoregionally using an indwelling infusion catheter to allow for repeated dosing. Four intratumoral doses of 5 x 106 GD2-directed mRNA CAR T cells induced significant tumor regression measured by bioluminescence in DMG model 7316-6349 (p&lt;0.0001). In addition, GD2-directed mRNA CAR T cells prolonged survival of mice harboring the aggressive DMG model SU-DIPG13P* by 61% (mean survival 29 days versus 18 days, p&lt;0.01) following four intratumoral doses of 4 x 106 CAR T cells. No GD2-directed CAR T cell treatment-related deaths or toxicities were observed. These data highlight the utility of using mRNA to titrate CAR T cell therapy in the brain, and establish GD2-directed mRNA CAR T cells as a safe and effective method for treating DMG.

IMMU-11. LOCOREGIONAL DELIVERY OF TRANSIENT GD2 CAR T CELLS FOR SAFE AND EFFECTIVE TREATMENT OF DIPG

Diffuse intrinsic pontine glioma (DIPG) is a universally fatal pediatric brain tumor with a median survival of one year. Recently Mount et al (Nat Med 2018) discovered the disialoganglioside GD2 is present at high levels on the surface of DIPG and can be targeted using GD2-directed CAR T cells. However, permanently expressed CAR T cells created by lentiviral transduction resulted in a significant number of deaths from tumor swelling with uncontrolled T cell proliferation. We hypothesized that using mRNA to create transient GD2-directed CAR T cells delivered locally with repeated dosing would result in a safer yet equally effective way to treat DIPG using CAR T cell therapy. In vitro studies using mRNA GD2-directed CAR T cells resulted in robust tumor cytotoxicity and T cell degranulation across a panel of six DIPG cell lines. Using an orthotopic murine model of SU-DIPGXIIIP*, an extremely aggressive model, we delivered of a single dose of two million mRNA GD2-directed CAR T cells locoregionally to the pons via stereotactic injection. The mRNA GD2-directed CAR T cells resulted in no toxic deaths of the mice. In addition, a single dose of mRNA CAR T cells targeting GD2 prolonged survival of the mice by a median of six days (p<0.05). Ongoing studies using an indwelling catheter for repeated dosing of mRNA CAR T cells are currently underway and results expected at the time of presentation. This work will form of the basis of an mRNA CAR T cell trial targeting GD2 for patients with DIPG.

Susceptibility to prosocial and antisocial influence in adolescence

Introduction

Adolescents are particularly susceptible to social influence and previous studies have shown that this susceptibility decreases with age. The current study used a cross-sectional experimental paradigm to investigate the effect of age and puberty on susceptibility to both prosocial and antisocial influence.

Methods

Participants (N = 520) aged 11–18 from London and Cambridge (United Kingdom) rated how likely they would be to engage in a prosocial (e.g. “help a classmate with their work”) or antisocial (e.g. “make fun of a classmate”) act. They were then shown the average rating (in fact fictitious) that other adolescents had given to the same question, and were then asked to rate the same behaviour again.

Results

Both prosocial and antisocial influence decreased linearly with age, with younger adolescents being more socially influenced when other adolescents’ ratings were more prosocial and less antisocial than their own initial rating. Both antisocial and prosocial influence significantly decreased across puberty for boys but not girls (independent of age).

Conclusions

These findings suggest that social influence declines with increasing maturity across adolescence. However, the exact relationship between social influence and maturity is dependent on the nature of the social influence and gender. Understanding when adolescents are most susceptible to different types of social influence, and how this might influence their social behaviour, has important implications for understanding adolescent social development.

Determination of Semicarbazide in Fresh Egg and Whole Egg Powder by Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Validation Study

An interlaboratory validation study was conducted according to harmonized protocols to evaluate the effectiveness of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of semicarbazide (SEM) in fresh whole egg and in an industrially processed whole egg powder. The sample was extracted with hydrochloric acid and derivatized with 2-nitrobenzaldehyde, with 1,2-[15N213C]SEM as the internal standard. The extract was neutralized and purified on a solid-phase extraction cartridge. SEM was determined by reversed-phase LC with detection by MS/MS. Five fresh egg samples, of which 3 were obtained from hens fed nitrofurazone (NFZ), one was spiked with SEM at 50 μg/kg and one was a blank sample, and 5 industrial whole egg powder samples, of which 3 were spiked with fresh whole egg from hens fed NFZ, one was spiked with SEM at 350 μg/kg, and one was a blank sample, were sent to 15 laboratories in 10 different European countries. Results were obtained from 12 participants. Average recoveries of SEM from the fresh egg and the egg powder samples were 105.3 and 121.3%, respectively. The relative standard deviation for repeatability (RSDr) ranged from 2.9 to 9.3%, and the relative standard deviation for reproducibility (RSDR) ranged from 22.5 to 38.1%. The method showed acceptable within- and between-laboratory precision for both matrixes, as evidenced by the HorRat values, at the target levels for the determination of SEM.

Determination of Semicarbazide in Baby Food by Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Validation Study

An interlaboratory validation study funded by the European Commission, Directorate General for Health and Consumer Protection (DG SANCO), was conducted to evaluate the effectiveness of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of semicarbazide (SEM) in different types of baby food at a possible future European regulatory limit (10 ng/g). The test portion of the sample was extracted with hydrochloric acid, and the analyte was derivatized with 2-nitrobenzaldehyde, with 1,2-[15N2, 13C] SEM as an internal standard. The extract was neutralized and then purified on a solid-phase extraction cartridge. The SEM was determined by reversed-phase LC with detection by MS/MS. Apple puree, rice pudding, and meat/vegetable meal baby food materials, spiked with SEM at levels of about 3, 10, and 30 ng/g, respectively, were sent to 20 laboratories in 12 different European countries, which submitted results from 17 participants. Recoveries ranged from 88.8 to 106.1%. Based on results for spiked samples (blind pairs at 3 levels), the relative standard deviations for repeatability (RSDr) ranged from 4.2 to 6.9% and the relative standard deviations for reproducibility (RSDR) ranged from 16.6 to 24.3%. The method showed acceptable within- and between-laboratory precision for all 3 matrixes, as evidenced by HorRat values, at the target levels for the determination of SEM.

Programming effects of maternal and gestational obesity on offspring metabolism and metabolic inflammation

With the increasing prevalence of obesity in women of reproductive age there is a need to understand the ramifications of this on offspring. The purpose of this study is to investigate the programming effects of maternal obesity during preconception and the preconception/gestational period on adiposity and adipose tissue inflammation in offspring using an animal model. Adult female C57Bl/6J mice were assigned either normal diet, high fat diet (HFD) prior to pregnancy, or HFD prior to and through pregnancy. Some offspring were maintained on normal diet while others started HFD later in life. Offspring were assessed for body composition and metabolic responses. Lipid storing tissues were evaluated for expansion and inflammation. Male offspring from the preconception group had the greatest weight gain, most subcutaneous adipose tissue, and largest liver mass when introduced to postnatal HFD. Male offspring of the preconception/gestation group had worsened glucose tolerance and an increase in resident (CD11c⁻) adipose tissue macrophages (ATMs) when exposed to postnatal HFD. Female offspring had no significant difference in any parameter between the diet treatment groups. In conclusion, this study demonstrates that prenatal and pregnancy windows have independent programming effects on offspring. Preconception exposure affects body composition and adiposity while gestation exposure affects metabolism and tissue immune cell phenotypes.

183 Risk of Hypoglycaemia in Older Patients in Residential Care on Oral Hypoglycaemic Medication

Background

Diabetes mellitus (DM) is common in older patients in residential care(RC) with prevalence ranging from 11-36%.Guidlines(1) on glucose targets to avoid the risk of hypoglycaemia or hyperglycaemia respectively in older people recommend avoiding a fasting glucose on treatment of 6mmol/L or a random glucose level higher than 11.0mmol/L. An HbA1c of 53to 59mmol/mol(7-7.5%) should be aimed for although this may need adjusting in RC and StoppFrail guidelines suggest a target of HbA1c of <8%(64mmol/mol). We assessed the prevalence, drug treatment and glycaemic control in 107 older patients in residential care at two sites in Dublin.

Methods

Patients with DM were identified from review of medical notes. Hypoglycaemic treatment whether oral hypoglycemic drugs(OHD) or insulin, capillary blood glucose measurements(CBGM) over the previous 28 day period, HbA1c values and weight change over the previous year respectively were tabulated from patient records.

Results

Sixteen patients (15%) aged 66-93 were documented with DM. Eight (50%) were on no hypoglycaemic treatment in whom OHD had been discontinued in 2 patients over the previous 6 months because of risk of hypoglycaemia.. Six patients (38%) were only on OHD, whilst 2 were on insulin. Of the 6 patients on OHD, CABGM were below 6mmol/L in 3 patients (50%) with no values above 11mmol/L. All 3 patients had lost weight ( 2.5-6.8Kg) over the previous year and HbA1c levels were below 53mmol/mol (7%) in all 3 patients.

Conclusion

Although our numbers are small, 50% of our patients in residential care on OHD are at risk of hypoglycemia possibly related to weight loss. Reducing or discontinuing their OHD may be appropriate.

The effect of social preference on academic diligence in adolescence

In the current study, we were interested in whether adolescents show a preference for social stimuli compared with non-social stimuli in the context of academic diligence, that is, the ability to expend effort on tedious tasks that have long-term benefits. Forty-five female adolescents (aged 11-17) and 46 female adults (aged 23-33) carried out an adapted version of the Academic Diligence Task (ADT). We created two variations of the ADT: a social ADT and non-social ADT. Individuals were required to freely split their time between an easy, boring arithmetic task and looking at a show-reel of photographs of people (in the social ADT) or landscapes (in the non-social ADT). Individuals also provided enjoyment ratings for both the arithmetic task and the set of photographs they viewed. Adolescents reported enjoying the social photographs significantly more than the non-social photographs, with the converse being true for adults. There was no significant difference in the time spent looking at the social photographs between the adolescents and adults. However, adults spent significantly more time than adolescents looking at the non-social photographs, suggesting that adolescents were less motivated to look at the non-social stimuli. Further, the correlation between self-reported enjoyment of the pictures and choice behaviour in the ADT was stronger for adults than for adolescents in the non-social condition, revealing a greater discrepancy between self-reported enjoyment and ADT choice behaviour for adolescents. Our results are discussed within the context of the development of social cognition and introspective awareness between adolescence and adulthood.

Pilot evaluation of Enterococcus faecium SF68 as adjunctive therapy for oclacitinib-responsive adult atopic dermatitis in dogs

OBJECTIVE

To evaluate the adjunctive effect of supplementation with Enterococcus faecium SF68 (FortiFlora; Purina Pro Plan Veterinary Diets) on oclacitinib (Apoquel, Zoetis) dose reduction, while maintaining or reducing the Pruritus Visual Analog Score and Canine Atopic Dermatitis Extent and Severity Index values in client-owned adult dogs with environmental atopic dermatitis.

MATERIALS AND METHODS

Enrolled dogs had exhibited control of atopic dermatitis on oclacitinib for at least 6 months before, and continuing throughout, the study. Dogs with non-seasonal pruritus were blindly randomised to receive either SF68 (1×10⁸ colony forming units/g orally twice daily) or placebo for 12 weeks. After 8 weeks of supplementation, oclacitinib dose was decreased by approximately 25%, aiming to maintain and reduce the clinical disease scores.

RESULTS

Supplementation with SF68 was associated with no difference in oclacitinib dose reduction versus placebo in 21 client-owned dogs with atopic dermatitis. Clinical disease scores were not different between groups at study completion.

CLINICAL SIGNIFICANCE

Further larger-scale studies are warranted to investigate optimal strain(s), dosing and duration of probiotic supplementation as an adjunctive strategy in management of canine atopic dermatitis.

A Dosimetric Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including the Internal Mammary Chain

AIMS

Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs).

MATERIALS AND METHODS

In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance.

RESULTS

One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P < 0.0001) and VMAT (P < 0.0001) techniques. There was no advantage in target volume coverage or OAR doses for PBT(vDIBH) compared with PBT(FB).

CONCLUSIONS

Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics.

β-γ and isomeric decay spectroscopy of 168Dy

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.

A Multibacteriocin Cheese Starter System, Comprising Nisin and Lacticin 3147 in Lactococcus lactis, in Combination with Plantaricin from Lactobacillus plantarum

Functional starter cultures demonstrating superior technological and food safety properties are advantageous to the food fermentation industry. We evaluated the efficacies of single- and double-bacteriocin-producing starters of Lactococcus lactis capable of producing the class I bacteriocins nisin A and/or lacticin 3147 in terms of starter performance. Single producers were generated by mobilizing the conjugative bacteriophage resistance plasmid pMRC01, carrying lacticin genetic determinants, or the conjugative transposon Tn5276, carrying nisin genetic determinants, to the commercial starter L. lactis CSK2775. The effect of bacteriocin coproduction was examined by superimposing pMRC01 into the newly constructed nisin transconjugant. Transconjugants were improved with regard to antimicrobial activity and bacteriophage insensitivity compared to the recipient strain, and the double producer was immune to both bacteriocins. Bacteriocin production in the starter was stable, although the recipient strain proved to be a more efficient acidifier than transconjugant derivatives. Overall, combinations of class I bacteriocins (the double producer or a combination of single producers) proved to be as effective as individual bacteriocins for controlling Listeria innocua growth in laboratory-scale cheeses. However, using the double producer in combination with the class II bacteriocin producer Lactobacillus plantarum or using the lacticin producer with the class II producer proved to be most effective for reducing bacterial load. As emergence of bacteriocin tolerance was reduced 10-fold in the presence of nisin and lacticin, we suggest that the double producer in conjunction with the class II producer could serve as a protective culture providing a food-grade, multihurdle approach to control pathogenic growth in a variety of industrial applications.IMPORTANCE We generated a suite of single- and double-bacteriocin-producing starter cultures capable of generating the class I bacteriocin lacticin 3147 or nisin or both bacteriocins simultaneously via conjugation. The transconjugants exhibited improved bacteriophage resistance and antimicrobial activity. The single producers proved to be as effective as the double-bacteriocin producer at reducing Listeria numbers in laboratory-scale cheese. However, combining the double producer or the lacticin-producing starter with a class II bacteriocin producer, Lactobacillus plantarum LMG P-26358, proved to be most effective at reducing Listeria numbers and was significantly better than a combination of the three bacteriocin-producing strains, as the double producer is not inhibited by either of the class I bacteriocins. Since the simultaneous use of lacticin and nisin should reduce the emergence of bacteriocin-tolerant derivatives, this study suggests that a protective starter system produced by bacteriocin stacking is a worthwhile multihurdle approach for food safety applications.

The UK HeartSpare Study (Stage II): Multicentre Evaluation of a Voluntary Breath-hold Technique in Patients Receiving Breast Radiotherapy

AIMS

To evaluate the feasibility and heart-sparing ability of the voluntary breath-hold (VBH) technique in a multicentre setting.

MATERIALS AND METHODS

Patients were recruited from 10 UK centres. Following surgery for early left breast cancer, patients with any heart inside the 50% isodose from a standard free-breathing tangential field treatment plan underwent a second planning computed tomography (CT) scan using the VBH technique. A separate treatment plan was prepared on the VBH CT scan and used for treatment. The mean heart, left anterior descending coronary artery (LAD) and lung doses were calculated. Daily electronic portal imaging (EPI) was carried out and scanning/treatment times were recorded. The primary end point was the percentage of patients achieving a reduction in mean heart dose with VBH. Population systematic (Σ) and random errors (σ) were estimated. Within-patient comparisons between techniques used Wilcoxon signed-rank tests.

RESULTS

In total, 101 patients were recruited during 2014. Primary end point data were available for 93 patients, 88 (95%) of whom achieved a reduction in mean heart dose with VBH. Mean cardiac doses (Gy) for free-breathing and VBH techniques, respectively, were: heart 1.8 and 1.1, LAD 12.1 and 5.4, maximum LAD 35.4 and 24.1 (all P<0.001). Population EPI-based displacement data showed Σ =+1.3-1.9 mm and σ=1.4-1.8 mm. Median CT and treatment session times were 21 and 22 min, respectively.

CONCLUSIONS

The VBH technique is confirmed as effective in sparing heart tissue and is feasible in a multicentre setting.

Sexually dimorphic myeloid inflammatory and metabolic responses to diet-induced obesity

It is well known in clinical and animal studies that women and men have different disease risk as well as different disease physiology. Women of reproductive age are protected from metabolic and cardiovascular disease compared with postmenopausal women and men. Most murine studies are skewed toward the use of male mice to study obesity-induced metabolic dysfunction because of similar protection in female mice. We have investigated dietary obesity in a mouse model and have directly compared inflammatory responses in males and females. In this review we will summarize what is known about sex differences in diet-induced inflammation and will summarize our data on this topic. It is clear that sex differences in high-fat diet-induced inflammatory activation are due to cell intrinsic differences in hematopoietic responses to obesogenic cues, but further research is needed to understand what leads to sexually dimorphic responses.