Testicular germ cell tumour cells release microRNA-containing extracellular vesicles that induce phenotypic and genotypic changes in cells of the tumour microenvironment

Malignant germ-cell-tumours (GCTs) are characterised by microRNA (miRNA/miR-) dysregulation, with universal over-expression of miR-371~373 and miR-302/367 clusters regardless of patient age, tumour site, or subtype (seminoma/yolk-sac-tumour/embryonal carcinoma). These miRNAs are released into the bloodstream, presumed within extracellular-vesicles (EVs) and represent promising biomarkers. Here, we comprehensively examined the role of EVs, and their miRNA cargo, on (fibroblast/endothelial/macrophage) cells representative of the testicular GCT (TGCT) tumour microenvironment (TME). Small RNA next-generation-sequencing was performed on 34 samples, comprising representative malignant GCT cell lines/EVs and controls (testis fibroblast [Hs1.Tes] cell-line/EVs and testis/ovary samples). TME cells received TGCT co-culture, TGCT-derived EVs, and a miRNA overexpression system (miR-371a-OE) to assess functional relevance. TGCT cells secreted EVs into culture media. MiR-371~373 and miR-302/367 cluster miRNAs were overexpressed in all TGCT cells/subtypes compared with control cells and were highly abundant in TGCT-derived EVs, with miR-371a-3p/miR-371a-5p the most abundant. TGCT co-culture resulted in increased levels of miRNAs from the miR-371~373 and miR-302/367 clusters in TME (fibroblast) cells. Next, fluorescent labelling demonstrated TGCT-derived EVs were internalised by all TME (fibroblast/endothelial/macrophage) cells. TME (fibroblast/endothelial) cell treatment with EVs derived from different TGCT subtypes resulted in increased miR-371~373 and miR-302/367 miRNA levels, and other generic (eg, miR-205-5p/miR-148-3p) and subtype-specific (seminoma, eg, miR-203a-3p; yolk-sac-tumour, eg, miR-375-3p) miRNAs. MiR-371a-OE in TME cells resulted in increased collagen contraction (fibroblasts) and angiogenesis (endothelial cells), via direct mRNA downregulation and alteration of relevant pathways. TGCT cells communicate with nontumour stromal TME cells through release of EVs enriched in oncogenic miRNAs, potentially contributing to tumour progression.

COVID-19 Pandemic Associations on Mental and Physical Health in African Americans Participating in a Behavioral Intervention

The COVID-19 pandemic has had disproportionate effects on communities of color, with higher death rates among African Americans (AA). The purpose of this study was to assess associations in African Americans' mental and physical health with the COVID-19 pandemic. Data for this study came from a larger nutrition intervention of AAs in the Southeastern United States, the Nutritious Eating with Soul study. Data collected before and after March 15, 2020 (the day when local South Carolina schools and businesses closed), were analyzed to assess the association of the pandemic on participants' stress, control of healthy eating, physical activity, and body mass index. Repeated measures analysis of covariance using full maximum likelihood estimation to handle missing data was used. At the onset of the COVID-19 pandemic, 150 participants were enrolled in the study (48.2 ± 10.6 years old, 79% female, 75% with college degree or higher). Participants' reporting of stress did not show statistically significant change over time. Cognitive control increased 1.43 points (F = 20.60, p < 0.0001) and body mass index increased 0.72 kg/m2 (F = 10.68, p = 0.001). Future longitudinal studies should investigate how the COVID-19 pandemic continues to present challenges to understanding and improving health among African Americans. The study is registered at www.clinicaltrials.gov NCT03354377.

Trauma-informed prevention programmes for depression, anxiety, and substance use among young people: protocol for a mixed-methods systematic review

BACKGROUND

Mental ill-health and substance use bear a substantial burden and harm on young people and often arise from co-occurring and compounding risk factors, such as traumatic stress. Trauma-informed prevention of mental ill-health and substance use demonstrates significant promise in reducing this burden. A systematic literature review is required to identify and summarise the effectiveness, feasibility, acceptability, and design principles underpinning existing trauma-informed mental ill-health and/or substance use prevention programmes for young people aged 12-24 years.

METHODS

MEDLINE, Embase, CINAHL, PsychINFO, and Cochrane Library will be searched from 2012 through September 2022. Reference lists of included articles will be citation-chained. Title and abstracts will be screened and two reviewers will review articles full-text. One reviewer will extract data from eligible articles using a piloted data extraction form, and 20% of the data will be verified by a second reviewer. Risk of bias will be assessed using the Cochrane risk-of-bias tool for randomised trials (RoB 2), Risk of Bias in Non-randomised Studies of Interventions (ROBINS-I), and The Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies and The Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research (CASP), depending on the study type. Characteristics of existing trauma-informed mental ill-health and/or substance use prevention programmes for young people will be summarised narratively. Effectiveness, feasibility, and acceptability will be qualitatively described and summarised, with proportions and effect sizes quantitatively synthesised, where possible.

DISCUSSION

Trauma-informed approaches to prevention demonstrate significant promise, yet to date, no study has systematically summarised and synthesised the available literature. To fill this gap, the present review will systematically identify and summarise the effectiveness, feasibility, acceptability, and design principles underpinning existing trauma-informed mental health and/or substance use prevention programmes for young people aged 12-24. This review will inform the development, adaptation, evaluation, and implementation of future trauma-informed mental ill-health and substance use prevention programmes for young people. Findings will inform critical efforts to interrupt and prevent already elevated trajectories of mental ill-health, substance use, and related harms among those young people exposed to adversity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022353883.

Targeting oncogenic microRNAs from the miR-371~373 and miR-302/367 clusters in malignant germ cell tumours causes growth inhibition through cell cycle disruption

BACKGROUND

MiR-371~373 and miR-302/367 cluster over-expression occurs in all malignant germ cell tumours (GCTs), regardless of age (paediatric/adult), site (gonadal/extragonadal), or subtype [seminoma, yolk sac tumour (YST), embryonal carcinoma (EC)]. Six of eight microRNAs from these clusters contain the seed sequence 'AAGUGC', determining mRNA targeting. Here we sought to identify the significance of these observations by targeting these microRNAs functionally.

METHODS

We targeted miR-371~373 and/or miR-302/367 clusters in malignant GCT cell lines, using CRISPR-Cas9, gapmer primary miR-302/367 transcript inhibition, and peptide nucleic acid (PNA) or locked nucleic acid (LNA)-DNA inhibition targeting miR-302a-d-3p, and undertook relevant functional assays.

RESULTS

MiR-302/367 cluster microRNAs made the largest contribution to AAGUGC seed abundance in malignant GCT cells, regardless of subtype (seminoma/YST/EC). Following the unsuccessful use of CRISPR-Cas9, gapmer, and PNA systems, LNA-DNA-based targeting resulted in growth inhibition in seminoma and YST cells. This was associated with the de-repression of multiple mRNAs targeted by AAGUGC seed-containing microRNAs, with pathway analysis confirming predominant disruption of Rho-GTPase signalling, vesicle organisation/transport, and cell cycle regulation, findings corroborated in clinical samples. Further LNA-DNA inhibitor studies confirmed direct cell cycle effects, with an increase of cells in G0/G1-phase and a decrease in S-phase.

CONCLUSION

Targeting of specific miR-371~373 and miR-302/367 microRNAs in malignant GCTs demonstrated their functional significance, with growth inhibition mediated through cell cycle disruption.

Quality and Safety Considerations in Image Guided Radiation Therapy: An ASTRO Safety White Paper Update

PURPOSE/OBJECTIVE(S)

This updated report on image guided radiation therapy (IGRT) is based on a consensus-based white paper previously published by the American Society for Radiation Oncology (ASTRO) addressing patient safety. In the past decade, IGRT technology and procedures have progressed significantly and are now more commonly used. The use of IGRT has now extended beyond high-precision treatments, such as stereotactic radiosurgery and stereotactic body radiation therapy, and into routine clinical practice for many treatment techniques and anatomic sites. Therefore, quality and treatment planning and delivery considerations for these techniques are paramount for patient safety.

MATERIALS/METHODS

In 2021, ASTRO convened an interdisciplinary task force to assess the original IGRT white paper and update content where appropriate. Recommendations were created using a consensus-building methodology, and task force members indicated their level of agreement based on a 5-point Likert scale from "strongly agree" to "strongly disagree." A prespecified threshold of ≥75% of raters who selected "strongly agree" or "agree" indicated consensus.

RESULTS

The IGRT white paper was published (Pract Radiat Oncol. 2022 Dec) and endorsed by the American Association of Physicists in Medicine (AAPM), American Association of Medical Dosimetrists, and American Society of Radiologic Technologists. Since the first IGRT paper was published by ASTRO in 2013, significant technological advancement has taken place. New and updated considerations in personnel requirements, staffing, education and training, equipment and technological requirements, quality management and assurance, IGRT program management, and safety considerations were reported. A 17-point consensus was reached and recommended in 5 areas surrounding program development, quality assurance, quality management, treatment delivery, and vendor engagement (Table 5, Summary of key recommendations).

CONCLUSION

This IGRT white paper builds on the previous version and uses other guidance documents to primarily focus on processes related to quality and safety. IGRT requires an interdisciplinary team-based approach, staffed by appropriately trained specialists, as well as significant personnel resources, specialized technology, and implementation time. A thorough feasibility analysis of resources is required and should be discussed with all personnel before undertaking new imaging techniques. A comprehensive quality-assurance program must be developed to ensure IGRT is performed safely and effectively. As IGRT technologies continue to improve or emerge, existing practice guidelines should be updated regularly according to the latest AAPM Task Group reports. Patient safety in the application of IGRT is everyone's responsibility, and professional organizations, regulators, vendors, and end-users must demonstrate strong commitments to ensure that the highest levels of safety are achieved.

Small non-coding RNA sequencing reveals global dysregulation of piwi-interacting RNA (piRNA) expression in gonadal malignant germ cell tumours

BACKGROUND

Analyses of small non-coding RNA (ncRNA) expression in malignant germ cell tumours (GCTs) have focused on microRNAs (miRNAs). As GCTs all arise from primordial germ cells, and piwi-interacting RNAs (piRNAs) have important roles in maintaining germline integrity via transposon silencing, we hypothesised that malignant GCTs are characterised by fundamental piRNA dysregulation.

AIMS

We undertook global small ncRNA sequencing in malignant GCTs, in order to describe small ncRNA expression changes for both miRNAs and piRNAs.

MATERIALS AND METHODS

We performed small ncRNA next generation sequencing on a representative panel of 47 samples, comprising malignant GCT (n = 31) and control (n = 16) tissues/cell lines. Following quality control and normalisation, filtered count reads were used for differential miRNA and piRNA expression analyses via DESeq2. Predicted mRNA targets for piRNAs were identified and utilised for pathway enrichment analyses.

RESULTS

Overall, miRNAs and piRNAs comprised 21.9% and 43.0% of small ncRNA species, respectively. There were 749 differentially expressed miRNAs in malignant GCTs, of which 536 (72%) were over-expressed and 213 (28%) under-expressed. The top-ranking over-expressed miRNAs were exclusively from the miR-371∼373 and miR-302/367 clusters. The most significantly under-expressed miRNAs were miR-100-5p, miR-214-3p, miR-125b-5p, and let-7 family members, including miR-202-3p. There were 1,121 differentially expressed piRNAs in malignant GCTs, of which 167 (15%) were over-expressed and 954 (85%) under-expressed. Of note, of the top-20 differentially expressed piRNAs, 16 were over-expressed, of which piR-hsa-2506793 was both top-ranking and most abundant. Mobile element (ME; i.e., transposon) associated piRNAs comprised 166 (15%) of the 1,121 differentially expressed piRNAs, of which 165 (>99%) were downregulated. The remaining 955 (85%) non-ME-associated piRNAs may have wider cellular roles. To explore this, predicted mRNA targets of differentially expressed piRNAs identified putative involvement in cancer-associated pathways.

CONCLUSION

This study confirms previous miRNA observations, giving credence to our novel demonstration of global piRNA dysregulation in gonadal malignant GCTs, through both ME and non-ME associated pathways, which likely contributes to GCT pathogenesis. This article is protected by copyright. All rights reserved.

Esophageal cooling during ablation of persistent atrial fibrillation is associated with improved freedom from arrhythmia at one-year follow up

Background

Various factors influence successful freedom from atrial arrhythmia after pulmonary vein isolation (PVI) with radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). Lesion transmurality and continuity (as measured by the Continuity Index) are two important factors, and these can be worsened by pauses in RF energy application due to esophageal overheating. Proactive esophageal cooling precludes the need for premature cessation of power, avoiding partially-formed lesions and the need to “hop-scotch” in the left atrium. The resulting improvement in lesion continuity may improve long-term freedom from atrial arrhythmia after PVI, particularly in patients with persistent AF, where more posterior wall ablation is often necessary.

Purpose

Determine differences in freedom from arrhythmia at one year between patients receiving LET monitoring and those receiving esophageal cooling during PVI for persistent AF.

Methods

We reviewed data from two healthcare systems for patient rhythm status at one-year follow up after PVI for the treatment of persistent or long-standing persistent AF. We then determined Kaplan-Meier estimates of freedom from arrhythmia (AF, atrial flutter, and atrial tachycardia), and compared these between patients receiving esophageal cooling and those treated with traditional LET monitoring.

Results

A total of 252 patients received PVI for persistent or long-standing persistent AF and had data available for review. Of these, 148 received LET monitoring (with either a single or multi-sensor temperature probe), and 104 received active cooling with a dedicated esophageal cooling device. Mean age and gender for each group was similar (67.2, range 21 to 88 years, 36% female for LET monitoring, and 67.8, range 32 to 89 years, 30% female for esophageal cooling). KM estimates for freedom from AF at the one-year follow-up were 44.2% for LET monitored patients and 79.3% for actively cooled patients (P=0.01).

Conclusions

Freedom from atrial arrhythmia at one-year after PVI for persistent AF is associated with significant improvement when using active esophageal cooling rather than LET monitoring.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Attune Medical

The impact of bone mineral density screening on incident fractures and healthcare resource utilization among postmenopausal breast cancer survivors treated with aromatase inhibitors

Bone mineral density screening prior to initiating aromatase inhibitor therapy was associated with lower incident bone fractures and healthcare resource utilization among postmenopausal breast cancer survivors.

INTRODUCTION

Postmenopausal women with hormone receptor-positive breast cancer (BC) often receive aromatase inhibitor (AI) therapy. However, AIs induce bone loss and BC survivors are at an increased risk of bone fractures. This study determined whether receipt of baseline dual-energy x-ray absorptiometry (DXA) screening is associated with decreased incident fractures and lower healthcare resource utilization.

METHODS

We retrospectively analyzed 22,713 stage 0-III primary BC survivors who received AI therapy ≤ 1 year prior to BC diagnosis from the Medicare-Linked Surveillance, Epidemiology, and End-Results database. We categorized DXA screening for those who had a procedural claim within 12 months prior through 6 months after first AI claim. We used propensity score methods to assess the association of DXA screening with bone fractures and health resource utilization.

RESULTS

Of the study cohort, 62% received a DXA screening. Women with comorbid dementia, renal disease, and congestive heart failure were less likely to receive a DXA. After adjusting for confounders, BC survivors who received a DXA had a 32% decreased risk of any bone fracture compared to those who did not (hazard ratio (HR): 0.68, 95% confidence interval (CI): 0.60-0.76, p < 0.001). Similarly, those who received a DXA were less likely to be hospitalized (HR 0.73 (0.62-0.86)) or use outpatient services (HR 0.85 (0.74-0.97)).

CONCLUSIONS

Bone density screening is associated with decreased incident bone fractures and a lower likelihood of utilizing healthcare resource for fracture-related events. Postmenopausal BC survivors treated with AIs should undergo appropriate bone density screening to reduce morbidity, mortality, and health care expenses.

Development and operation of the defence COVID-19 lab as a SARS-CoV-2 diagnostic screening capability for UK military personnel

BACKGROUND

In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel.

LABORATORY STRUCTURE AND RESOURCE

The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists.

LABORATORY RESULTS

Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started.

CONCLUSIONS

Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.

P-363 Systematic review and meta-analysis of female lifestyle factors and risk of recurrent pregnancy loss (RPL)

Study question

What is the impact of female lifestyle (BMI, smoking, caffeine, alcohol) on RPL in the general population and on further miscarriage in the RPL population?

Summary answer

Being underweight and BMI&gt;25 contributes significantly to increased risk of RPL (general population). BMI&gt;25 or BMI&gt;30 increases the risk of further miscarriages (RPL population)

What is known already

Lifestyle factors are modifiable and in many instances lifestyle optimisation enhances the chances of a positive reproductive outcome. Whilst the specific mechanisms leading to early pregnancy loss is still relatively unknown, poor lifestyle is associated with a hostile reproductive environment whereby optimal embryo implantation and securement of a pregnancy is compromised. The peri-implantation intrauterine environment is a key determinant of pre-implantation embryo development and early programming. RPL is a complex disease where causation has been attributed to numerous factors and whilst it is known that lifestyle factors affect sporadic miscarriage, the extent of this on RPL is less well known.

Study design, size, duration

A systematic review and meta-analysis was performed to assess the associations between lifestyle factors and RPL. Studies that analysed RPL in the context of BMI, smoking, alcohol and caffeine intake were included. The primary and secondary outcomes were odds of having RPL in the general population and odds of further miscarriage, respectively.

Participants/materials, setting, methods

Studies were included if they explored women of reproductive age who had been exposed to an aspect of female lifestyle. We excluded studies which assessed the effectiveness of an intervention aimed at altering lifestyle and studies which assessed lifestyle factors in the context of IVF outcomes or associations with PCOS. We screened all studies, reviewing full papers where required and disregarding those that did not meet the eligibility criteria using a double-blind approach.

Main results and the role of chance

The systematic search identified a total of 24, 705 records and an additional 194 records through hand-searching of references. 16 studies were included in this systematic review and meta-analysis. None of these studies were RCTs; there were 8 case control studies, 6 cohort studies, 1 survey-based study and 1 cross-sectional study.

Underweight and women with BMI &gt; 25 are at higher odds of RPL in the general population (OR 1.2, 95% CI 1.12–1.28 and OR 1.21, 95% CI 1.06–1.38, respectively). In women with RPL, having BMI &gt; 30 and BMI &gt; 25 has increased odds of further miscarriages (OR 1.77, 95% CI 1.25–2.50 and OR 1.35, 95% CI 1.07–1.72, respectively).

The odds of RPL in the general population is increased in women who were cigarette smokers compared to non-smokers but this is not statistically significant (OR 1.62, 95% CI 0.90–2.93). Alcohol intake compared with no alcohol intake increases the risk of RPL, however this is not statistically significant (OR 1.12, 95% CI 0.88–1.44). The odds of RPL in the higher caffeine intake group (&gt;99mg/day) compared to the lower caffeine intake group (≤99mg/day) is higher but not significant (OR 1.35, 95% CI 0.83–2.19).

Limitations, reasons for caution

The quality of the evidence was low or very low, mainly due to heterogeneity in study populations. There were inconsistencies in the definition of RPL, some studies included women with ‘≥3 consecutive miscarriages’, others ‘≥2 miscarriages’. We did not explore the impact of male lifestyle on the risk of RPL.

Wider implications of the findings

Being underweight and BMI&gt;25 contributes significantly to increased risk of RPL. BMI&gt;25 or BMI&gt;30 increases the risk of further miscarriages in the RPL population. Studies addressing the effects of alcohol, cigarette smoking and caffeine on the risk of RPL with optimisation of BMI in this cohort of women are warranted.

Trial registration number

Is the frequency of low plasma-mannose-binding lectin (p-MBL) levels increased in recurrent pregnancy loss (RPL) after spontaneous conception or IVF/ICSI and recurrent implantation failure (RIF)?

GCT-04. Pattern of Treatment Failures in Central Nervous System Non-Germinomatous Germ Cell Tumors (CNS-NGGCT): A Pooled Analysis of Clinical Trials

BACKGROUND: Central Nervous System- Non-Germinomatous Germ Cell Tumors (CNS-NGGCT) are rare but curable tumors. Due to their rarity, treatment failures remain a poorly characterized disease with unfavorable outcomes. In this study, we sought to characterize the treatment failures in a large cohort of prospectively treated patients. METHODS: European and North American clinical trials for patients with CNS-NGGCT (SIOP-GCT96, SFOP-TGM TC 90/92, COG-ACNS0122 and COG-ACNS1123) were pooled for analysis. Additionally, patients included and treated in the UK and France national registries under strict protocol-guidelines were included as an independent, non-overlapping cohort. RESULTS: A total of 118 patients experienced a treatment failure. Twenty-four patients had progressive disease during therapy and additional eleven patients were diagnosed with growing teratoma syndrome (GTS). Patients with GTS are significantly younger and present with local failures and negative tumor markers. Eighty-three individuals experienced disease relapses after treatment ended. Patients’ metastatic relapses presented significantly earlier than local relapses and were associated with tumor marker elevation (OR: 4.39; p=0.026). In our analysis, focal or whole ventricular (WVI) radiation therapy was not associated with an increased risk of metastatic relapses. CONCLUSIONS: Herein, we present the largest pooled dataset of prospectively treated patients with relapsed CNS-NGGCT. Our study identified younger age and negative tumor markers to be characteristic of GTS. Additionally, we elucidated that metastatic relapses occur earlier than local relapses, are associated with elevated tumor markers, and are not associated with the field of radiation therapy. These findings are of utmost importance for the planning of future clinical trials and the implementation of surveillance strategies in these patients.

Arrhythmia recurrence reduction with an active esophageal cooling device during radiofrequency ablation

Funding Acknowledgements

Type of funding sources: None.

Background

As the burden of atrial fibrillation continues to rise with an aging population, there have been contrasting positions on the efficacy of left atrial ablation. While ablation techniques have continued to improve over the past decades, arrhythmia recurrence rates must be further reduced given the burden of ablation on patients. Since continuity of lesion sets has been associated with greater lesion durability, it has been theorized that the use of active esophageal cooling may facilitate greater freedom from arrhythmia.

Purpose

In order to investigate the association between use of active esophageal cooling and arrhythmia recurrence, we performed a multicenter retrospective study of arrhythmia recurrence rates in patients that received active cooling and compared them to those that received luminal esophageal temperature (LET) monitoring.

Methods

In this study, follow up data were collected from patients that underwent pulmonary vein isolation (PVI) at three separate large medical centers. Data were contained in a prospective hospital registry, a prospective physician registry, or the electronic health record, depending on the center. For each patient included, we recorded whether their ablation utilized LET monitoring or active esophageal cooling, along with their rhythm status at 1-year follow up. Rhythm status at follow-up was determined by either electrocardiogram, Holter monitor, or wearable heart rate monitor. Kaplan-Meier (KM) curves were created for freedom-from-arrhythmia at one year comparing those in the LET monitoring group to those in the active cooling group.

Results

Follow up data were collected from 1035 patients. There were 560 patients that received LET monitoring during their original ablation, and 475 patients that underwent active esophageal cooling. KM estimates for freedom-from-arrhythmia at one year were 42% in the LET monitored group and 65% in the actively cooled group (P&lt;.001).

Conclusion

In this large multicenter study, there is a significant increase in freedom-from-arrhythmia at one year follow-up among patients that received active esophageal cooling as compared to those that underwent LET monitoring.

Effect of a proactive esophageal cooling device on procedure length - a multicenter comparison of persistent and paroxysmal atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

During left atrial ablation for the treatment of atrial fibrillation (AF), effective esophageal protection is essential for reducing or preventing thermal injury. Traditional methods include luminal esophageal temperature (LET) monitoring that lead to frequent pauses in the procedure when temperature alarms alert operators to dangerous temperature levels. While there have been recent studies that demonstrate an association between active esophageal cooling and a reduction in procedure duration regardless of AF type, these retrospective studies have been conducted at single or joint centers which may lead to confounding from other time-saving variables that have changed over time.

Purpose

Consequently, we sought to perform a large-scale multicenter comparison to better elucidate the association between procedure length and the use of active cooling in patients with persistent and paroxysmal atrial fibrillation.

Methods

In this study, we collected data from three large hospital centers, one hospital-maintained registry, one physician-maintained registry, and one through EHR data review and aggregated in groups separated by AF type as well as whether the patients received active cooling or LET monitoring. We then compared median procedure durations in each group.

Results

There were a total of 753 patients included in this study. Of the 360 patients with paroxysmal AF, 179 received active esophageal cooling while 181 underwent LET monitoring. In the persistent AF group with 393 patients, 157 received active esophageal cooling and 236 underwent LET monitoring. Among patients with paroxysmal AF, the median mean procedure duration was 137 minutes in the LET monitored group, and 90 minutes in the actively cooled group with an overall reduction of 47 minutes (P&lt;.001). In patients with persistent AF, the median procedure duration was 148 minutes in the LET monitored group and 94 minutes in the actively cooled group with an overall reduction of 54 minutes (P&lt;.001). The relative reduction as a percent of total procedure time was 34%, and 36%, for paroxysmal and persistent AF cases, respectively.

Conclusion

In this large multicenter review, there is a significant reduction in procedure length when using active esophageal cooling, regardless of AF type.

Pattern of treatment failures in patients with central nervous system non-germinomatous germ cell tumors (CNS-NGGCT): A pooled analysis of clinical trials

BACKGROUND

Central Nervous System Non-Germinomatous Germ Cell Tumors (CNS-NGGCT) are rare but curable tumors. Due to their rarity, patients with treatment failures remain a poorly characterized group with unfavorable outcomes. In this study, we sought to characterize patients with treatment failures in a large, prospectively treated cohort.

METHODS

European and North American clinical trials for patients with CNS-NGGCT (SIOP-GCT-96, SFOP-TGM-TC 90/92, COG-ACNS0122, and COG-ACNS1123) were pooled for analysis. Additionally, patients included and treated in the UK and France national registries under strict protocol guidelines were included as an independent, non-overlapping cohort.

RESULTS

A total of 118 patients experienced a treatment failure. Twenty-four patients had progressive disease during therapy, and additional 11 patients were diagnosed with growing teratoma syndrome (GTS). Patients with GTS are significantly younger and present with local failures and negative tumor markers. Eighty-three individuals experienced disease relapses after treatment ended. Patients' metastatic relapses presented significantly earlier than local relapses and were associated with tumor marker elevation (OR: 4.39; P = .026). In our analysis, focal or whole-ventricular radiation therapy was not associated with an increased risk of metastatic relapses.

CONCLUSIONS

Herein, we present the largest pooled dataset of prospectively treated patients with relapsed CNS-NGGCT. Our study identified younger age and negative tumor markers to be characteristic of GTS. Additionally, we elucidated that metastatic relapses occur earlier than local relapses are associated with elevated tumor markers and are not associated with the field of radiation therapy. These findings are of utmost importance for the planning of future clinical trials and the implementation of surveillance strategies in these patients.

Investigation of the combined efficacy of two Haemonchus contortus vaccines in weaner Merino sheep

This study was conducted to investigate whether co-administration of Barbervax® (Bvax) with Haemonchus contortus surface larval antigen (HcsL3) would increase the protective efficacy and duration of protection against H. contortus infection in weaner Merino sheep. A total of 132 10-month-old weaned Merino ewe lambs were randomly allocated into six treatment groups (n = 22). Sheep were vaccinated four times with either Barbervax® (Bvax), H. contortus L3 surface larval antigen (HcsL3), combined vaccination (Bvax + HcsL3), Bvax + AlOH, HcsL3 + Saponin or remained as unvaccinated controls. Aluminium hydroxide (AlOH) and saponin adjuvants were included in HcsL3 and Bvax vaccines respectively. The first three vaccinations were given at 4 week intervals and the fourth vaccination provided as booster, 9 weeks later. All animals were treated with Zolvix™ (monepantel 25 mg/mL, Elanco) at the third vaccination and commencing two weeks later, artificially trickle infected with H. contortus L3. Worm egg count (WEC), packed cell volume (PCV), antibody titre and bodyweight were measured throughout the study as was specific antibody directed against each antigen using ELISA. The administration of Bvax and HcsL3, alone or in combination, induced an antibody response against HcsL3 but only the Bvax and the combined treatment elicited an antibody response to the Bvax antigen. The targeting of HcsL3 by each vaccine was confirmed by immunofluorescence staining of H. contortus L3. However, only the booster vaccination in the Bvax treatments reduced WEC to levels below untreated controls. The HcsL3 vaccine did not reduce WEC in this experiment and co-administration with Bvax did not improve the efficacy and duration of protection against H. contortus infection.

Effects of COVID-19 on EMS Refresher Course Completion and Delivery

Introduction: The COVID pandemic has significantly impacted educational development and delivery, yet there is little quantitative research on this topic. The primary objective of this study was to compare the total number of Emergency Medical Service (EMS) Refresher (ER) course completions during 2020 versus prior years. Secondary outcomes examined in person versus on-line/distributive learning during the study period. Methods: The Commission on Accreditation for Prehospital Continuing Education (CAPCE) is the only national organization that accredits continuing education (CE) for paramedics and EMTs and currently has a database with over 14 million CE records. The total number of ER course completions each month in 2020 were compared to 2019 and 2018. We also compared the different educational format types: live in-person (LIP), asynchronous on-line distributive learning (DL), and virtual instructor lead training (VILT) synchronous DL courses. Data was analyzed using descriptive and two-way ANOVA statistics. Results: There were 1,922,783 ER course completions in 2020 versus 1,166,335 in 2019 and 1,074,636 in 2018, representing a 179% increase during the study period. Asynchronous DL course completions in 2020 were 1,830,513 EMS versus 1,078,580 in 2019 and 987,749 in 2018 a 185% increase over the three-year study period. Asynchronous DL monthly means by year was statistically significant, F(2, 99) = 95.632, p < .001. Mean monthly LIP and VLIT educational deliveries by year were not significantly different, p = .802, p = .754, respectively. Total LIP course completions in 2020 were 20,045 versus 51,552 in 2019 and 63,058 in 2018. In 2020 LIP courses made up only 1.0% (20,045/1,922,783) of all ER completions. This study was limited to only EMS professionals taking ER course completions in the CAPCE database. However EMS is not unique, since previous research has suggested that DL has flourished in other health care disciplines while LIP courses have continued to decrease. Conclusion: This large nationwide study of EMS profession has shown the trend toward DL education and a trend away from LIP courses. Future studies should examine the advantages and disadvantages of DL education.

559 IDENTIFYING PATIENTS WITH MOOD DISORDER FOLLOWING ADMISSION WITH HIP FRACTURE WITH A VIEW TO STARTING TREATMENT & PROVIDE ADVICE

Introduction

The signs of depression in the elderly often go unnoticed. The MDT at RSCH observed that low mood could negatively impact on patient’s recovery, affecting pain thresholds and leading to poor engagement with rehabilitation. Proactive identification and management of mood disorder is an important part of CGA, but not routinely performed. The aim of this QI project is to improve identification and management of mood disorder in patients over 65 years admitted to RSCH with hip fractures by introducing a standardised assessment tool to guide appropriate interventions.

Method

Notes of patients with hip fracture admitted over a four-month period were retrospectively reviewed to establish if patients were screened for low mood. A mood screening tool, Cornell Score, was chosen and implemented by OT’s and junior doctors over a four-month period. Those identified with depression or probable depression were issued verbal advice, an information leaflet and follow-up arranged.

Results

Ninety-eight patients were included in the retrospective cohort; There was no indication that mood was considered or assessed at any point during admission. During the four-month prospective period, 86 patients (96%) were screened for low mood; 9% had major depression and 16% probable depression. Feedback from our occupational therapists and doctors was positive, with the tool being easy to use in patients with or without cognitive impairment. Much of the assessment could be incorporated into initial assessment or in gaining collateral history. Anecdotally, considering patients psychological well-being had a positive impact on inpatient therapy sessions guided the MDT in supporting the patient appropriately.

Conclusion

Implementation of a standardised and validated mood screening tool enabled us to identify that a quarter (25%) of the patients had, or probably had depression. This allowed us to intervene with simple measures such as verbal advice and an information leaflet and consider pharmacological intervention where appropriate.

Identification of monoclonal antibodies suitable for blocking IGF-1 receptors in the horse

Prolonged hyperinsulinemia is thought to be the cause of equine endocrinopathic laminitis, a common and crippling disease of the foot, for which there are no pharmacologic treatments other than pain relief. It has been suggested that insulin causes its effects on the lamellae by activating IGF-1 receptors (IGF-1R), as insulin receptors (InsR) are scarce in this tissue, whereas IGF-1R are abundant and become downregulated after prolonged insulin infusion. As a first step toward confirming this mechanism and beginning to develop a therapeutic anti-IGF-1R monoclonal antibody (mAb) for horses, it was necessary to identify available human IGF-1R mAbs that would recognize equine receptors. Four IGF-1R mAbs were tested using soluble equine IGF-1R, with ELISA and flow cytometry. Frozen equine lamellar and liver tissue was also used in radioligand binding assays. The results demonstrated that only one of the mAbs tested (mAb1) was able to compete effectively with IGF-1 for binding to its receptors in equine lamellar tissue, with an IC₅₀ of 5 to 159 ng/mL. None of the 4 mAbs were able to bind to equine hepatic InsR. This study has generated valuable structure-activity information and has identified a prototype anti-IGF-1R mAb suitable for further development.

A novel cardiac signal processing system for electrophysiology procedures: early insights from the pure ep 2.0 study

Background

Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has remained relatively unchanged for the past two decades.

Purpose

We test a new platform, the PURE EP™ 2.0 system (PEP; BioSig Technologies) for signal processing and display.

Methods

Identical electrocardiographic and intracardiac signal data were recorded during 15 AF ablation procedures from the PEP system, the signal recording system, and the 3D mapping system (Figure). The collected signals underwent blinded, controlled evaluation by three independent electrophysiologist reviewers to determine whether the PEP signals are a viable alternative to conventional sources and if it provides additional or clearer diagnostic information. Reviewers were asked to record the quality of each signal sample on a scale of 1–10 and select a rationale for their rating in a dropdown menu. Each paired signal rating was collected and unblinded for the analysis. If the reviewer rated the samples in the set within 1 point of each other, the PEP sample was deemed equivalent to the control. Using a 2+1 statistical method, the ratings from the three reviewers were then compared looking for at least two positive reviews for each PEP sample.

Results

Based on the ratings for each pair of signals, a cumulative total of 29 PEP signals out of 34 (85.3%) were rated as statistically equivalent or better for this dataset. In 35.5% of samples, the reviewers selected PEP because “more signal components were visible”.

Conclusion

The PURE EP 2.0 system is able to produce reliable and high-quality signals when compared to available standard of care systems. Further studies with larger dataset across multiple sites are needed to validate these results.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): BioSig Technologies

The molecular landscape and associated clinical experience in infant medulloblastoma: prognostic significance of second-generation subtypes

AIMS

Biomarker-driven therapies have not been developed for infant medulloblastoma (iMB). We sought to robustly sub-classify iMB, and proffer strategies for personalized, risk-adapted therapies.

METHODS

We characterized the iMB molecular landscape, including second-generation subtyping, and the associated retrospective clinical experience, using large independent discovery/validation cohorts (n = 387).

RESULTS

iMB_Grp3 (42%) and iMB_SHH (40%) subgroups predominated. iMB_Grp3 harboured second-generation subtypes II/III/IV. Subtype II strongly associated with large-cell/anaplastic pathology (LCA; 23%) and MYC amplification (19%), defining a very-high-risk group (0% 10yr overall survival (OS)), which progressed rapidly on all therapies; novel approaches are urgently required. Subtype VII (predominant within iMB_Grp4 ) and subtype IV tumours were standard risk (80% OS) using upfront CSI-based therapies; randomized-controlled trials of upfront radiation-sparing and/or second-line radiotherapy should be considered. Seventy-five per cent of iMB_SHH showed DN/MBEN histopathology in discovery and validation cohorts (P < 0.0001); central pathology review determined diagnosis of histological variants to WHO standards. In multivariable models, non-DN/MBEN pathology was associated significantly with worse outcomes within iMB_SHH . iMB_SHH harboured two distinct subtypes (iMB_SHH-I/II ). Within the discriminated favourable-risk iMB_SHH DN/MBEN patient group, iMB_SHH-II had significantly better progression-free survival than iMB_SHH-I , offering opportunities for risk-adapted stratification of upfront therapies. Both iMB_SHH-I and iMB_SHH-II showed notable rescue rates (56% combined post-relapse survival), further supporting delay of irradiation. Survival models and risk factors described were reproducible in independent cohorts, strongly supporting their further investigation and development.

CONCLUSIONS

Investigations of large, retrospective cohorts have enabled the comprehensive and robust characterization of molecular heterogeneity within iMB. Novel subtypes are clinically significant and subgroup-dependent survival models highlight opportunities for biomarker-directed therapies.

Compulsory admissions of patients with mental disorders: State of the art on ethical and legislative aspects in 40 European countries

Background.

Compulsory admission procedures of patients with mental disorders vary between countries in Europe. The Ethics Committee of the European Psychiatric Association (EPA) launched a survey on involuntary admission procedures of patients with mental disorders in 40 countries to gather information from all National Psychiatric Associations that are members of the EPA to develop recommendations for improving involuntary admission processes and promote voluntary care.

Methods.

The survey focused on legislation of involuntary admissions and key actors involved in the admission procedure as well as most common reasons for involuntary admissions.

Results.

We analyzed the survey categorical data in themes, which highlight that both medical and legal actors are involved in involuntary admission procedures.

Conclusions.

We conclude that legal reasons for compulsory admission should be reworded in order to remove stigmatization of the patient, that raising awareness about involuntary admission procedures and patient rights with both patients and family advocacy groups is paramount, that communication about procedures should be widely available in lay-language for the general population, and that training sessions and guidance should be available for legal and medical practitioners. Finally, people working in the field need to be constantly aware about the ethical challenges surrounding compulsory admissions.

P1379Fluoroscopy requirement reduction using an esophageal cooling protocol during left atrial ablation

Background

Ablation of the left atrium with radiofrequency (RF) energy is associated with some risks to the esophagus.  Cooling the esophagus has been used as one approach to reducing esophageal injury, most commonly with direct instillation of cold liquid via gastric tube placed in the esophagus.  A new esophageal cooling device avoids the risks of free liquid instillation by using a closed-loop system, and avoids the need for frequent repositioning or stopping of the procedure often required when utilizing luminal esophageal temperature (LET) monitoring.  This in turn may reduce fluoroscopy requirements for the procedure.

Purpose

Measure the difference in fluoroscopy time required during RF ablation using an esophageal cooling device protocol, and compare this to standard LET monitoring using single or multi-sensor temperature probes.

Methods

We obtained total fluoroscopy time per patient from records of RF ablation procedures performed by a two operators over a 12 month period.  We compared fluoroscopy times between patients treated with an esophageal cooling device to control patients who were treated with LET monitoring using either single-sensor or multi-sensor temperature probes.

Results

Fluoroscopy times were available for a total of 179 patients treated with an esophageal cooling device, and 118 patients treated with LET monitoring over the 12 month study period.  Mean fluoroscopy time for patients treated with esophageal cooling was 4.0 minutes (SD 4.9 minutes) with a median of 2.0 minutes (IQR 1.3 to 3.8 minutes).  Mean fluoroscopy time for patients undergoing LET monitoring was 5.5 minutes (SD 5.7 minutes) with a median of 3.0 minutes (IQR 1.9 to 8.4 minutes).  This difference represents a 27% reduction in mean fluoroscopy time, and a 33% reduction in median fluoroscopy time in the esophageal cooling group (p&lt;.001, Mann-Whitney U test).

Conclusions

 Fluoroscopy requirements were reduced by 27% with an esophageal cooling device when compared to standard LET monitoring.

The role of tumor markers for relapse detection in central nervous system non-germinomatous germ cell tumors (CNS-NGGCT): A pool analysis of cooperative group clinical trials

2503

Background: CNS-NGGCT are rare tumors that have been successfully treated with multimodal therapies. With a 5-yr EFS and OS of 72-84% and 82-93% respectively, surveillance and relapse detection is essential. Tumor marker (TM) elevation has proven to be a highly sensitive method of relapse detection in extra-cranial-NGGCT. We aim to determine the role of TM for relapse surveillance in children and adolescents with CNS-NGGCTs. Methods: European and North American data from germ cell tumor trials (SIOP GCT96, SFOP-TGM TC 90/92, COG-ACNS0122 and COG-ACNS1123) were pooled for analysis. Additionally, patients treated in the UK, Germany and France under strict protocol-guidelines were included. Details regarding imaging, pathology and TM elevation at diagnosis and relapse were collected. We report the proportion of relapses detectable by TM elevation. Results: Four-hundred and eighty-four patients enrolled in prospective cooperative group CNS-NGGCT trials from 1989 to 2016 were pooled for analysis. One-hundred and thirteen (23%) patients experienced a relapse/progression (SIOP GCT96: n = 57; SFOP TGM TC 90-92 n = 23, COG-ACNS0122 n = 16 & COG-ACNS1123 n = 17) and constitute the population of this report. Median age at diagnosis was 13 (range:1-30) years. The most common primary location was pineal in n = 60 (53%) patients. The site of relapse was available for 100 patients, 48 patients relapsed locally, 36 relapsed with distant disease, combined relapses were seen in 22 patients and 4 patients relapsed with TM elevation alone. TM in serum and/or CSF at diagnosis was available in 93(82%) patients, and in 90(80%) patients at the time of relapse. Eighty-four patients had TM available at both timepoints. At diagnosis 81 (96%) patients had TM elevation and 3 (4%) had negative TM. At relapse, 74(94%) patients with positive TM at diagnosis had TM elevation, while 7(6%) had TM negative. Conversely, 2/3 patients with negative TM at diagnosis, relapsed with elevated TM. Conclusions: Herein, we have assembled the largest prospective cohort to date of relapsed intracranial germ cell tumors. TM are highly sensitive detecting relapse/progression in CNS-NGGCT patients with elevated TM at diagnosis. The routine use of TM for relapse surveillance in patients with CNS-NGGCT can decrease the frequency of cross-sectional imaging, therefore, reducing lengthy hospital visits, sedation procedures and decreasing health-care costs.

28 Can Comprehensive Geriatric Assessment be Achieved in the Emergency Department?

Background

Our National Health Service is facing unprecedented challenges to accommodate our frailer healthcare users. The gold standard tool for the identification and management of frailty is the Comprehensive Geriatric Assessment (CGA) and has been shown to lead to better outcomes in terms of morbidity and mortality.

Introduction

With a largely elderly demographic profile in the East of England, the Norfolk and Norwich University Hospital opened the first Older People’s Emergency Department (OPED) in the UK in 2017. This work reviews the effectiveness of a geriatrician-led CGA in a dedicated OPED, which operates during daylight hours, compared to usual care in Accident & Emergency (A&E).

Methods

99 patients assessed in OPED and 99 patients assessed overnight in A&E during February 2019 were included in this retrospective study. Electronic case notes for each patient were reviewed by the authors and results were expressed as percentages.

Results

OPED outperformed A&E in all components of the CGA; strongest areas included assessing for pain, falls risk and activities of daily living. Both departments performed well in reviewing medications and assessing for safeguarding concerns. Areas for improvement include assessing for mood disorders, sensory impairment, discussing Do Not Attempt Cardiopulmonary Resuscitation status, and end of life care plans. The average length of stay of OPED patients was only 7.3 days compared to 8.7 days in A&E, and 89% of OPED patients were discharged back to their usual residences compared to 87% in A&E.

Conclusions

The improved CGA process in OPED has led to better outcomes, notably through a reduction in the average length of inpatient stay. Nevertheless, certain components of the CGA still require improvement. Further examination is needed to assess long-term mortality to support the use of CGA in the emergency setting.

Comparison of MICRO-ID Listeria Method with Conventional Biochemical Methods for Identification of Listeria Isolated From Food and Environmental Samples: Collaborative Study

Fourteen laboratories participated in a collaborative study to evaluate the ability of the MICRO-ID Listeria identification method to correctly identify Listeria isolated from food and environmental sources. Each collaborator received 60 isolates consisting of 51 Listeria and 9 non-Listeria cultures. All isolates were identified by conventional biochemical analyses in the principal laboratory. Cultures were checked for purity by Gram staining and examined for oxidase and catalase activities. Only Gram positive, oxidase negative, catalase positive cultures were tested with the method. Colonies from trypticase soy agar with 0.6% yeast extract were suspended in 4.6 ml_ physiological saline to a MacFarland No. 1 turbidity standard and used to inoculate the test strip. In addition, the hemolytic reaction of each isolate was determined by using the Christie-Atkins-Munch-Peterson (CAMP) test and by stabbing sheep blood agar. Identification of Listeria is based on the octal code obtained from the strip and the hemolytic reaction of the isolate. The MICRO-ID Listeria method agreed with conventional biochemical identification for 98.0% of L. monocytogenes, 77.1% of L. seeligeri, 98.0% of L ivanovii, 96.4% of L. grayi/L. murrayi, 73.9% of L. welshimeri, and 100% of L innocua isolates. A large percentage of errors in identification of the L. seeligeri and L ivanovii cultures was caused by inaccurate reading of the CAMP and hemolysis tests rather than errors in the test strip. The method was adopted first action by AOAC International.

The value of routine laboratory screening in the neonatal intensive care unit

BACKGROUND

Healthcare spending is expected to grow faster than the economy over the next decade, and the cost of prematurity increases annually. The aim of this study was to investigate the frequency of intervention after routine laboratory testing in preterm infants.

METHODS

This was a retrospective study of preterm infants (≤34 weeks) admitted to the NYU Langone Health NICU from June 2013 to December 2014. Data collected included demographics, results of laboratory tests, and resulting interventions. Intervention after a hemogram was defined as a blood transfusion. Intervention after a hepatic panel was defined as initiation or termination of ursodiol or change in dose of vitamin D. Subjects were stratified into 3 groups based on gestation (<28 weeks, 28-31 6/7 weeks, 32-34 weeks). Chi-square analysis was used to compare the frequency of intervention between the groups.

RESULTS

A total of 135 subjects were included in the study. The frequency of intervention after a hemogram was 8.4% in infants <28 weeks, 4.6% in infants 28-31 6/7 weeks, and 0% in infants 32-34 weeks; this difference was found to be statistically significant (p = 0.02). The frequency of intervention after a hepatic panel was 4.2% in infants <28 weeks, 5.7% in infants 28-31 6/7 weeks, and 0% in infants 32-34 weeks, which was not found to be a statistically significant different.

CONCLUSION

No interventions were undertaken post-routine laboratory testing in any infant 32-34 weeks and routine testing in this population may be unnecessary. Further studies are needed to elucidate if routine testing affects neonatal outcomes.

Characterization of insulin and IGF-1 receptor binding in equine liver and lamellar tissue: implications for endocrinopathic laminitis

Although it is well established that equine laminitis can be triggered by extreme hyperinsulinemia, the mechanism of insulin action is not known. High concentrations of insulin lead to separation of the weight-bearing apparatus from the hoof wall and are associated with an increased cycle of cell death and proliferation in the lamellae. Gene expression and immunohistochemistry studies have indicated that the lamellae are sparsely populated with insulin receptors, whereas IGF-1 receptors (IGF-1R) are abundant, suggesting that the action of insulin may be mediated by insulin binding to the IGF-1R. To investigate this possibility, cell membrane fragments containing IGF-1R were extracted from the livers of 6 horses and the lamellae of >50 horses euthanized for nonresearch purposes at an abattoir. Radioligand-binding studies using ¹²⁵I-IGF-1 and ¹²⁵I-insulin confirmed an abundance of high-affinity IGF-1R in the liver (K_D 0.11 nM, B_max 223 fmol/mg protein) and lamellae (K_D 0.16 nM, B_max 243 fmol/mg protein). However, the affinity of insulin for binding to the lamellar IGF-1R (K_i 934 nM) was >5,800 fold less than that of IGF-1, suggesting that insulin is unlikely to bind to equine IGF-1R at physiological concentrations. Although insulin receptors could be detected in the liver (K_D 0.48 nM, B_max 123 fmol/mg protein), they were barely detectable in lamellae (estimated B_max 14 fmol/mg protein). There was no evidence to support the presence of insulin/IGF-1 hybrid receptors in either tissue. These findings suggest that insulin does not act directly through IGF-1 receptors and that an alternative theory is required to explain the mechanism of insulin action in laminitis.

Structural Changes in Silicon Rubber Peritoneal Dialysis Catheters in Patients using Mupirocin at the Exit Site

Structural damage to polyurethane PD (peritoneal dialysis) catheters in patients using mupirocin ointment is widely appreciated, but damage to silicon rubber PD catheters is less well described. Ten catheters (6.6%) out of 152 were found to have structural alterations such as opacification, ballooning, thinning, and rupture. The duration of PD in these 10 patients ranged from 23 months to 80 months (mean duration 51.1 months). The frequency of mupirocin application varied from daily (2 cases) to 2-3 times per week (7 cases). In eight catheters opacification occurred at the exit site whereas one catheter showed opacification midway between the exit site and the titanium adaptor. One catheter showed opacification, ballooning, and thinning at the exit site ruptured in the form of two slit-like openings. In conclusion, various structural changes such as opacification, ballooning or thinning were seen in 6.6% of silicon rubber PD catheters in patients using mupirocin at the exit site. Although the mechanism remains elusive, mupirocin or the antiseptic solution alone or in combination may be contributory. We believe that this is an under-reported complication and encourage other health care givers to incorporate a search for such changes during clinic visits.

"Future-Proofing" Blood Processing for Measurement of Circulating miRNAs in Samples from Biobanks and Prospective Clinical Trials

Background: Quantifying circulating nucleic acids is an important new approach to cancer diagnosis/monitoring.Methods: We compared the suitability of serum versus plasma for measuring miRNAs using qRT-PCR and assessed how preanalytic variables that can affect circulating tumor DNA (ctDNA) quantification in plasma also influence miRNA levels.Results: Across 62 blood-derived specimens, plasma samples in EDTA, Streck-DNA, and Streck-RNA tubes showed significantly higher C_t values for multiple housekeeping miRNAs, compared with serum samples. For the EDTA-plasma tubes, this difference was only seen when including the high-speed centrifugation protocol used to optimize ctDNA extraction. In plasma samples derived from blood stored at room temperature for up to 14 days (conditions that typically apply to samples processed for biobanking), levels of endogenous housekeeping miRNAs gradually increased, in parallel with the hemolysis marker hsa-miR-451a, consistent with release from blood cells/platelets. It was necessary to normalize levels of the housekeeping miRNAs to those of hsa-miR-451a, to obtain the stable values needed for referencing test miRNA levels.Conclusions: Our data indicate that plasma samples prepared for ctDNA extraction are suboptimal for miRNA quantification and require the incorporation of multiple data normalization steps. For prospective studies designed to measure both miRNAs and ctDNA, the most suitable approach would be to obtain both serum (for miRNAs) and plasma (for ctDNA). If only plasma can be collected, we recommend an initial low-speed centrifugation step, followed by aliquoting the supernatant into parallel samples, one for direct miRNA quantification, and the other for a further high-speed centrifugation step to optimize ctDNA retrieval.Impact: These recommendations will help "future-proof" clinical studies in which quantification of circulating miRNAs is a component. Cancer Epidemiol Biomarkers Prev; 27(2); 208-18. ©2017 AACR.

Minimal methylation classifier (MIMIC): A novel method for derivation and rapid diagnostic detection of disease-associated DNA methylation signatures

Rapid and reliable detection of disease-associated DNA methylation patterns has major potential to advance molecular diagnostics and underpin research investigations. We describe the development and validation of minimal methylation classifier (MIMIC), combining CpG signature design from genome-wide datasets, multiplex-PCR and detection by single-base extension and MALDI-TOF mass spectrometry, in a novel method to assess multi-locus DNA methylation profiles within routine clinically-applicable assays. We illustrate the application of MIMIC to successfully identify the methylation-dependent diagnostic molecular subgroups of medulloblastoma (the most common malignant childhood brain tumour), using scant/low-quality samples remaining from the most recently completed pan-European medulloblastoma clinical trial, refractory to analysis by conventional genome-wide DNA methylation analysis. Using this approach, we identify critical DNA methylation patterns from previously inaccessible cohorts, and reveal novel survival differences between the medulloblastoma disease subgroups with significant potential for clinical exploitation.