Protocolized reduction of non-resuscitation fluids versus usual care in septic shock patients (REDUSE): a randomized multicentre feasibility trial

BACKGROUND/PURPOSE

Non-resuscitation fluids constitute the majority of fluid administered for septic shock patients in the intensive care unit (ICU). This multicentre, randomized, feasibility trial was conducted to test the hypothesis that a restrictive protocol targeting non-resuscitation fluids reduces the overall volume administered compared with usual care.

METHODS

Adults with septic shock in six Swedish ICUs were randomized within 12 h of ICU admission to receive either protocolized reduction of non-resuscitation fluids or usual care. The primary outcome was the total volume of fluid administered within three days of inclusion.

RESULTS

Median (IQR) total volume of fluid in the first three days, was 6008 ml (interquartile range [IQR] 3960-8123) in the restrictive fluid group (n = 44), and 9765 ml (IQR 6804-12,401) in the control group (n = 48); corresponding to a Hodges-Lehmann median difference of 3560 ml [95% confidence interval 1614-5302]; p < 0.001). Outcome data on all-cause mortality, days alive and free of mechanical ventilation and acute kidney injury or ischemic events in the ICU within 90 days of inclusion were recorded in 98/98 (100%), 95/98 (98%) and 95/98 (98%) of participants respectively. Cognition and health-related quality of life at six months were recorded in 39/52 (75%) and 41/52 (79%) of surviving participants, respectively. Ninety out of 134 patients (67%) of eligible patients were randomized, and 15/98 (15%) of the participants experienced at least one protocol violation.

CONCLUSION

Protocolized reduction of non-resuscitation fluids in patients with septic shock resulted in a large decrease in fluid administration compared with usual care. A trial using this design to test if reducing non-resuscitation fluids improves outcomes is feasible.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT05249088, 18 February 2022. https://clinicaltrials.gov/ct2/show/NCT05249088.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Multi-scale characterisation of homologous recombination deficiency in breast cancer

BACKGROUND

Homologous recombination is a robust, broadly error-free mechanism of double-strand break repair, and deficiencies lead to PARP inhibitor sensitivity. Patients displaying homologous recombination deficiency can be identified using 'mutational signatures'. However, these patterns are difficult to reliably infer from exome sequencing. Additionally, as mutational signatures are a historical record of mutagenic processes, this limits their utility in describing the current status of a tumour.

METHODS

We apply two methods for characterising homologous recombination deficiency in breast cancer to explore the features and heterogeneity associated with this phenotype. We develop a likelihood-based method which leverages small insertions and deletions for high-confidence classification of homologous recombination deficiency for exome-sequenced breast cancers. We then use multinomial elastic net regression modelling to develop a transcriptional signature of heterogeneous homologous recombination deficiency. This signature is then applied to single-cell RNA-sequenced breast cancer cohorts enabling analysis of homologous recombination deficiency heterogeneity and differential patterns of tumour microenvironment interactivity.

RESULTS

We demonstrate that the inclusion of indel events, even at low levels, improves homologous recombination deficiency classification. Whilst BRCA-positive homologous recombination deficient samples display strong similarities to those harbouring BRCA1/2 defects, they appear to deviate in microenvironmental features such as hypoxic signalling. We then present a 228-gene transcriptional signature which simultaneously characterises homologous recombination deficiency and BRCA1/2-defect status, and is associated with PARP inhibitor response. Finally, we show that this signature is applicable to single-cell transcriptomics data and predict that these cells present a distinct milieu of interactions with their microenvironment compared to their homologous recombination proficient counterparts, typified by a decreased cancer cell response to TNFα signalling.

CONCLUSIONS

We apply multi-scale approaches to characterise homologous recombination deficiency in breast cancer through the development of mutational and transcriptional signatures. We demonstrate how indels can improve homologous recombination deficiency classification in exome-sequenced breast cancers. Additionally, we demonstrate the heterogeneity of homologous recombination deficiency, especially in relation to BRCA1/2-defect status, and show that indications of this feature can be captured at a single-cell level, enabling further investigations into interactions between DNA repair deficient cells and their tumour microenvironment.

Leveraging ecological momentary assessment to understand variability in food parenting practices within a low-income racially/ethnically diverse sample of parents of preschoolers

Children's eating behaviors are shaped significantly by their home food environment, including exposure to food parenting practices. The current study leveraged ecological momentary assessment (EMA) to describe how food parenting practices used to feed preschoolers (n = 116) differed across contextual factors around eating, including type of eating occasion (i.e., meals vs. snacks), day of the week (i.e., weekend vs. weekday), who initiated the meal (parent vs. child), emotional climate of the eating occasion. Parent perceptions of how well the eating occasion went, including how well the child ate and whether the food parenting practices worked as intended were also explored. Parent use of specific food parenting practices, situated within four higher-order domains (i.e., structure, autonomy support, coercive control, indulgent), was found to differ by type of eating occasion; parents engaged in a higher proportion of structure practices at meals than at snacks. Use of specific food parenting practices differed by mealtime emotional climate; parent use of structure and autonomy support was associated with eating occasions described as relaxed, enjoyable, neutral, and fun. Finally, parent perception of how well the child ate differed by use of specific food parenting practices; during eating occasions when parent's felt their child ate "not enough", they used less autonomy support and more coercive control compared to eating occasions where the child ate "enough and a good balance." Leveraging EMA allowed for increased understanding of the variability in food parenting practices and contextual factors. Findings may be utilized to inform the development of larger-scale studies seeking to understand why parents choose specific approaches to feeding their children, as well as the impact of various approaches to child feeding on child health outcomes.

Localized immune surveillance of primary melanoma in the skin deciphered through executable modeling

While skin is a site of active immune surveillance, primary melanomas often escape detection. Here, we have developed an in silico model to determine the local cross-talk between melanomas and Langerhans cells (LCs), the primary antigen-presenting cells at the site of melanoma development. The model predicts that melanomas fail to activate LC migration to lymph nodes until tumors reach a critical size, which is determined by a positive TNF-α feedback loop within melanomas, in line with our observations of murine tumors. In silico drug screening, supported by subsequent experimental testing, shows that treatment of primary tumors with MAPK pathway inhibitors may further prevent LC migration. In addition, our in silico model predicts treatment combinations that bypass LC dysfunction. In conclusion, our combined approach of in silico and in vivo studies suggests a molecular mechanism that explains how early melanomas develop under the radar of immune surveillance by LC.

Prevalence of early postpartum depression and associated risk factors among selected women in southern Malawi: a nested observational study

BACKGROUND

The birth of a child should be a time of celebration. However, for many women, childbirth represents a time of great vulnerability to becoming mentally unwell, a neglected maternal morbidity. This study aimed to determine the prevalence of early postpartum depression (PPD) and its associated risk factors among women giving birth at health facilities in southern Malawi. Identifying women vulnerable to PPD will help clinicians provide appropriately targeted interventions before discharge from the maternity ward.

METHOD

We conducted a nested cross-sectional study. Women were screened for early PPD using a locally validated Edinburgh Postpartum Depression Scale (EPDS) as they were discharged from the maternity ward. The prevalence of moderate or severe (EPDS ≥ 6) and severe (EPDS ≥ 9) PPD was determined, including 95% confidence intervals (CI). Data on maternal age, education and marital status, income source, religion, gravidity, and HIV status, among others, were collected during the second trimester of pregnancy, and obstetric and infant characteristics during childbirth were examined as potential risk factors for early PPD using univariable and multivariable logistic regression analyses.

RESULTS

Data contributed by 636 women were analysed. Of these women, 9.6% (95% CI; 7.4-12.1%) had moderate to severe early PPD using an EPDS cut-off of ≥ 6, and 3.3% (95% CI; 2.1-5.0%) had severe early PPD using an EPDS cut-off of ≥ 9. Multivariable analyses indicated that maternal anaemia at birth (aOR; 2.65, CI; 1.49-4.71, p-value; 0.001) was associated with increased risk for moderate and/or severe early PPD, while live birth outcome (aOR; 0.15, 95% CI; 0.04-0.54, p-value; 0.004), being single compared to divorced/widowed (aOR; 0.09, 95% CI; 0.02-0.55, p-value; 0.009), and lower education level (aOR; 0.36, 95% CI; 0.20-0.65, p-value; 0.001) were associated with decreased risk. Being HIV positive (aOR; 2.88, 95% CI; 1.08-7.67, p-value; 0.035) was associated with severe PPD only.

CONCLUSION

The prevalence of early PPD was slightly lower in our selected sample compared to previous reports in Malawi and was associated with maternal anaemia at birth, non-live birth, being divorced/widowed and HIV-positive status. Therefore, health workers should screen for depressive symptoms in women who are at increased risk as they are discharged from the maternity ward for early identification and treatment.

HOXA9 has the hallmarks of a biological switch with implications in blood cancers

Blood malignancies arise from the dysregulation of haematopoiesis. The type of blood cell and the specific order of oncogenic events initiating abnormal growth ultimately determine the cancer subtype and subsequent clinical outcome. HOXA9 plays an important role in acute myeloid leukaemia (AML) prognosis by promoting blood cell expansion and altering differentiation; however, the function of HOXA9 in other blood malignancies is still unclear. Here, we highlight the biological switch and prognosis marker properties of HOXA9 in AML and chronic myeloproliferative neoplasms (MPN). First, we establish the ability of HOXA9 to stratify AML patients with distinct cellular and clinical outcomes. Then, through the use of a computational network model of MPN, we show that the self-activation of HOXA9 and its relationship to JAK2 and TET2 can explain the branching progression of JAK2/TET2 mutant MPN patients towards divergent clinical characteristics. Finally, we predict a connection between the RUNX1 and MYB genes and a suppressive role for the NOTCH pathway in MPN diseases.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Executable network of SARS-CoV-2-host interaction predicts drug combination treatments

The COVID-19 pandemic has pushed healthcare systems globally to a breaking point. The urgent need for effective and affordable COVID-19 treatments calls for repurposing combinations of approved drugs. The challenge is to identify which combinations are likely to be most effective and at what stages of the disease. Here, we present the first disease-stage executable signalling network model of SARS-CoV-2-host interactions used to predict effective repurposed drug combinations for treating early- and late stage severe disease. Using our executable model, we performed in silico screening of 9870 pairs of 140 potential targets and have identified nine new drug combinations. Camostat and Apilimod were predicted to be the most promising combination in effectively supressing viral replication in the early stages of severe disease and were validated experimentally in human Caco-2 cells. Our study further demonstrates the power of executable mechanistic modelling to enable rapid pre-clinical evaluation of combination therapies tailored to disease progression. It also presents a novel resource and expandable model system that can respond to further needs in the pandemic.

Interventions to prevent preterm delivery in women with short cervix before fetoscopic laser surgery for twin-twin transfusion syndrome

OBJECTIVE

Preoperative short cervical length (CL) remains a major risk factor for preterm birth after laser surgery for twin-twin transfusion syndrome (TTTS), but the optimal intervention to prolong pregnancy remains elusive. The objective of this study was to compare secondary methods for the prevention of preterm birth in twin pregnancies with TTTS undergoing fetoscopic laser photocoagulation (FLP), in the setting of a short cervix at the time of FLP, in five North American Fetal Treatment Network (NAFTNet) centers.

METHODS

This was a secondary analysis of data collected prospectively at five NAFTNet centers, conducted from January 2013 to March 2020. Inclusion criteria were a monochorionic diamniotic twin pregnancy complicated by TTTS, undergoing FLP, with preoperative CL < 30 mm. Management options for a short cervix included expectant management, vaginal progesterone, pessary (Arabin, incontinence or Bioteque cup), cervical cerclage or a combination of two or more treatments. Patients were not included if the intervention was initiated solely on the basis of having a twin gestation rather than at the diagnosis of a short cervix. Demographics, ultrasound characteristics, operative data and outcomes were compared. The primary outcome was FLP-to-delivery interval. Propensity-score matching was performed, with each treatment group matched (1:1) to the expectant-management group for CL, in order to estimate the effect of each treatment on the FLP-to-delivery interval.

RESULTS

A total of 255 women with a twin pregnancy complicated by TTTS and a short cervix undergoing FLP were included in the study. Of these, 151 (59%) were managed expectantly, 32 (13%) had vaginal progesterone only, 21 (8%) had pessary only, 21 (8%) had cervical cerclage only and 30 (12%) had a combination of treatments. A greater proportion of patients in the combined-treatment group had had a prior preterm birth compared with those in the expectant-management group (33% vs 9%; P = 0.01). Mean preoperative CL was shorter in the pessary, cervical-cerclage and combined-treatment groups (14-16 mm) than in the expectant-management and vaginal-progesterone groups (22 mm for both) (P < 0.001). There was no significant difference in FLP-to-delivery interval between the groups, nor in gestational age at delivery or the rate of live birth or neonatal survival. Vaginal progesterone was associated with a decrease in the risk of delivery before 28 weeks' gestation compared with cervical cerclage and combined treatment (P = 0.03). Using propensity-score matching for CL, cervical cerclage was associated with a reduction in FLP-to-delivery interval of 13 days, as compared with expectant management.

CONCLUSIONS

A large proportion of pregnancies with TTTS and a short maternal cervix undergoing FLP were managed expectantly for a short cervix, establishing a high (62%) risk of delivery before 32 weeks in this condition. No treatment that significantly improved outcome was identified; however, there were significant differences in potential confounders and there were also likely to be unmeasured confounders. Cervical cerclage should not be offered as a secondary prevention for preterm birth in twin pregnancies with TTTS and a short cervix undergoing FLP. A large randomized controlled trial is urgently needed to determine the effects of treatments for the prevention of preterm birth in these pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

1515 A Survey on The Perceived Effect of Background Music on Intra-Operative Stress, Anxiety and Surgical Task Load On the Operating Surgeon

Introduction

Music is commonly played in operating theatres throughout the world though its use remains controversial. There is growing literature supporting the notion that playing background music can improve a surgeon’s task performance and reduce performance stress. We present findings from our survey of surgeons about their perceptions of the effect of intra-operative music on their stress levels.

Method

Surgeons and registrars from three different specialties – general, vascular, and paediatric surgery – in a single tertiary centre were surveyed on their views on the effect of music in theatre. Two instruments were used to assess parameters of stress: the modified 6-point state trait anxiety inventory (STAI-6) and the surgical task load index (SURG-TLX).

Results

There were 35 respondents across the three surgical specialties (78% response rate). Pop and “easy listening” were the most popular genres. A majority felt music improved their temperament (75%) and perceived stress (63%). 59% of respondents reported no to low perceived anxiety with music, compared with 31% reporting moderate and 9% high anxiety based on STAI-6 parameters. Regarding SURG-TLX parameters and music, respondents overall perceived feeling less anxious, rushed and mentally fatigued though more distracted.

Conclusions

Music is generally thought to have positive subjective effects on the theatre environment with regards to anxiety levels, temperament, perceived stress, and parameters within the surgical task load index. This is counterbalanced by a smaller group of respondents who felt that music can impair communication and increase distraction within theatre. Music used appropriately may reduce perceptions of stress in theatre.

Mapping Rora expression in resting and activated CD4+ T cells

The transcription factor Rora has been shown to be important for the development of ILC2 and the regulation of ILC3, macrophages and Treg cells. Here we investigate the role of Rora across CD4+ T cells in general, but with an emphasis on Th2 cells, both in vitro as well as in the context of several in vivo type 2 infection models. We dissect the function of Rora using overexpression and a CD4-conditional Rora-knockout mouse, as well as a RORA-reporter mouse. We establish the importance of Rora in CD4+ T cells for controlling lung inflammation induced by Nippostrongylus brasiliensis infection, and have measured the effect on downstream genes using RNA-seq. Using a systematic stimulation screen of CD4+ T cells, coupled with RNA-seq, we identify upstream regulators of Rora, most importantly IL-33 and CCL7. Our data suggest that Rora is a negative regulator of the immune system, possibly through several downstream pathways, and is under control of the local microenvironment.

ACE inhibitors, angiotensin receptor blockers and endothelial injury in COVID-19

BACKGROUND

COVID-19 is caused by the coronavirus SARS-CoV-2, which uses angiotensin-converting enzyme 2 (ACE-2) as a receptor for cellular entry. It is theorized that ACE inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) may increase vulnerability to SARS-CoV-2 by upregulating ACE-2 expression, but ACE-I/ARB discontinuation is associated with clinical deterioration.

OBJECTIVE

To determine whether ACE-I and ARB use is associated with acute kidney injury (AKI), macrovascular thrombosis and in-hospital mortality.

METHODS

A retrospective, single-centre study of 558 hospital inpatients with confirmed COVID-19 admitted from 1 March to 30 April 2020, followed up until 24 May 2020. AKI and macrovascular thrombosis were primary end-points, and in-hospital mortality was a secondary end-point.

RESULTS

AKI occurred in 126 (23.1%) patients, 34 (6.1%) developed macrovascular thrombi, and 200 (35.9%) died. Overlap propensity score-weighted analysis showed no significant effect of ACE-I/ARB use on the risk of occurrence of the specified end-points. On exploratory analysis, severe chronic kidney disease (CKD) increases odds of macrovascular thrombi (OR: 8.237, 95% CI: 1.689-40.181, P = 0.009). The risk of AKI increased with advancing age (OR: 1.028, 95% CI: 1.011-1.044, P = 0.001) and diabetes (OR: 1.675, 95% CI: 1.065-2.633, P = 0.025). Immunosuppression was associated with lower risk of AKI (OR: 0.160, 95% CI: 0.029-0.886, P = 0.036). Advancing age, dependence on care, male gender and eGFR < 60 mL min^-1 /1.73 m² increased odds of in-hospital mortality.

CONCLUSION

We did not identify an association between ACE-I/ARB use and AKI, macrovascular thrombi or mortality. This supports the recommendations of the European and American Societies of Cardiology that ACE-Is and ARBs should not be discontinued during the COVID-19 pandemic.

163 Frailty, Doesn’t That Mean Birdlike? Research Into Attitudes and Understanding of Frailty in Undergraduate and Postgraduate Trainees

Introduction

Frailty is an increasingly recognised concept, with 25–50% of over 85’s estimated to be frail1,. Previous research considered medical students’ attitudes towards older people2, yet despite the correlation between frailty and increased age3, little is known about attitudes of healthcare professionals towards frailty.

We researched attitudes towards, and understanding of, frailty in undergraduate and postgraduate trainees, with a view to guiding future educational interventions.

Method

Approval was granted by Northumbria Healthcare NHS Foundation Trust (NHCT) Research and Development department, Newcastle University’s Research Management Group and the HRA.

3 cohorts were recruited; 3rd year Newcastle University MBBS Students, 5th year Newcastle University MBBS Students and Foundation Year 2 and Core Medical Trainees working for NHCT (junior doctors). Data was collected during scheduled teaching at NHCT and individuals were invited to participate via email prior to this. Those not participating were still required to attend the teaching. Participants provided written consent.

Within each cohort, small group discussions around frailty and Comprehensive Geriatric Assessment (CGA) were prompted using open questions (e.g. “what does frailty mean to you?”), during which participants anonymously submitted phrases to an online word-cloud generator. Discussions were audio recorded and transcribed.

Transcriptions and word-clouds were analysed using Simple Content Analysis. The over-arching themes within each cohort were identified and compared with other cohorts. Interpretations were reviewed by an independent researcher to enhance rigour.

Results

Each cohort associated frailty with older age and weakness, and often used it as a byword for complexity. Frailty was described as an abstract construct composed of personal experiences rather than an objectively defined descriptor. All associated it with negative emotions.

Cohorts differed in their approach, with 3rd year students primarily focussed on defining frailty, whereas junior doctors prioritised the clinical challenges it presented.

Junior doctors demonstrated limited understanding of CGA whilst undergraduate students were almost universally ignorant of it.

Conclusions

The lack of understanding around frailty and CGA is concerning given its high prevalence. The identification of negative emotions increases this concern. To challenge this, focussed educational interventions addressing understanding and attitudes ought to be developed for tomorrow’s doctors.

References

1. Clegg et al. Lancet 2013; 381: 752–62.

2. Samra et al. Age Ageing 2017; 46: 911–9.

3. Romero-Ortuno et al. Age Ageing 2012; 41: 684–9.

Validation of the National Institute of Neurological Disorders and Stroke Spinal Cord Injury MRI Common Data Elements Instrument

BACKGROUND AND PURPOSE

The National Institute of Neurological Disorders and Stroke common data elements initiative was created to provide a consistent method for recording and reporting observations related to neurologic diseases in clinical trials. The purpose of this study is to validate the subset of common data elements related to MR imaging evaluation of acute spinal cord injury.

MATERIALS AND METHODS

Thirty-five cervical and thoracic MR imaging studies of patients with acute spinal cord injury were evaluated independently in 2 rounds by 5 expert reviewers. Intra- and interrater agreement were calculated for 17 distinct MR imaging observations related to spinal cord injury. These included ordinal, categoric, and continuous measures related to the length and location of spinal cord hemorrhage and edema as well as spinal canal and cord measurements. Level of agreement was calculated using the interclass correlation coefficient and kappa.

RESULTS

The ordinal common data elements spinal cord injury elements for lesion center and rostral or caudal extent of edema or hemorrhage demonstrated agreement ranging from interclass correlation coefficient 0.68 to 0.99. Reproducibility ranged from 0.95 to 1.00. Moderate agreement was observed for absolute length of hemorrhage and edema (0.54 to 0.60) with good reproducibility (0.78 to 0.83). Agreement for the Brain and Spinal Injury Center score showed the lowest interrater agreement with an overall kappa of 0.27 (0.20, 0.34). For 7 of the 8 variables related to spinal cord injury, agreement improved between the first and second evaluation. Continuous diameter measures of the spinal cord and spinal canal using interclass correlation coefficient varied substantially (0.23 to 0.83).

CONCLUSIONS

Agreement was more consistent for the ordinal measures of spinal cord injury than continuous measures. Good to excellent agreement on length and location of spinal cord hemorrhage and edema can be achieved with ordinal measures alone.

Antiviral Activity of Reagents in Mouth Rinses against SARS-CoV-2

The oral cavity, an essential part of the upper aerodigestive tract, is believed to play an important role in the pathogenicity and transmission of SARS-CoV-2. The identification of targeted antiviral mouth rinses to reduce salivary viral load would contribute to reducing the COVID-19 pandemic. While awaiting the results of significant clinical studies, which to date do not exist, the commercial availability of mouth rinses leads us to search among them for reagents that would have specific antiviral properties with respect to SARS-CoV-2. The challenges facing this target were examined for 7 reagents found in commercially available mouth rinses and listed on the ClinicalTrials.gov website: povidone-iodine, chlorhexidine, hydrogen peroxide, cyclodextrin, Citrox, cetylpyridinium chloride, and essential oils. Because SARS-CoV-2 is an enveloped virus, many reagents target the outer lipid membrane. Moreover, some of them can act on the capsid by denaturing proteins. Until now, there has been no scientific evidence to recommend mouth rinses with an anti-SARS-CoV-2 effect to control the viral load in the oral cavity. This critical review indicates that current knowledge of these reagents would likely improve trends in salivary viral load status. This finding is a strong sign to encourage clinical research for which quality protocols are already available in the literature.

Executable cancer models: successes and challenges

Making decisions on how best to treat cancer patients requires the integration of different data sets, including genomic profiles, tumour histopathology, radiological images, proteomic analysis and more. This wealth of biological information calls for novel strategies to integrate such information in a meaningful, predictive and experimentally verifiable way. In this Perspective we explain how executable computational models meet this need. Such models provide a means for comprehensive data integration, can be experimentally validated, are readily interpreted both biologically and clinically, and have the potential to predict effective therapies for different cancer types and subtypes. We explain what executable models are and how they can be used to represent the dynamic biological behaviours inherent in cancer, and demonstrate how such models, when coupled with automated reasoning, facilitate our understanding of the mechanisms by which oncogenic signalling pathways regulate tumours. We explore how executable models have impacted the field of cancer research and argue that extending them to represent a tumour in a specific patient (that is, an avatar) will pave the way for improved personalized treatments and precision medicine. Finally, we highlight some of the ongoing challenges in developing executable models and stress that effective cross-disciplinary efforts are key to forward progress in the field.

Constructing and Analyzing Computational Models of Cell Signaling with BioModelAnalyzer

BioModelAnalyzer (BMA) is an open-source graphical tool for the development of executable models of protein and gene networks within cells. Based upon the Qualitative Networks formalism, the user can rapidly construct large networks, either manually or by connecting motifs selected from a built-in library. After the appropriate functions for each variable are defined, the user has access to three analysis engines to test the model. In addition to standard simulation tools, BMA includes an interface to the stability-testing algorithm and to a graphical Linear Temporal Logic (LTL) editor and analysis tool. Alongside this, we have developed a novel ChatBot to aid users constructing LTL queries and to explain the interface and run through tutorials. Here we present worked examples of model construction and testing via the interface. As an initial example, we discuss fate decisions in Dictyostelium discoidum and cAMP signaling. We go on to describe the workflow leading to the construction of a published model of the germline of C. elegans. Finally, we demonstrate how to construct simple models from the built-in network motif library. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Modeling the signaling network of Dictyostelium discoidum Basic Protocol 2: Modeling the germline progression of Caenorhabditis elegans Basic Protocol 3: Constructing a model of the cell cycle using motifs.

Parents' experiences of care following the loss of a baby at the margins between miscarriage, stillbirth and neonatal death: a UK qualitative study

OBJECTIVE

To explore the healthcare experiences of parents whose baby died either before, during or shortly after birth between 20⁺⁰ and 23⁺⁶  weeks of gestation in order to identify practical ways to improve healthcare provision.

DESIGN

Qualitative interview study.

SETTING

England through two parent support organisations and four NHS Trusts.

SAMPLE

A purposive sample of parents.

METHODS

Thematic analysis of semi-structured in-depth narrative interviews.

MAIN OUTCOME MEASURES

Parents' healthcare experiences.

RESULTS

The key overarching theme to emerge from interviews with 38 parents was the importance of the terminology used to refer to the death of their baby. Parents who were told they were 'losing a baby' rather than 'having a miscarriage' were more prepared for the realities of labour, the birth experience and for making decisions around seeing and holding their baby. Appropriate terminology validated their loss, and impacted on parents' health and wellbeing immediately following bereavement and in the longer term.

CONCLUSION

For parents experiencing the death of their baby at the margins between miscarriage, stillbirth and neonatal death, ensuring the use of appropriate terminology that reflects parents' preferences is vital. This helps to validate their loss and prepare them for the experiences of labour and birth. Reflecting parents' language preferences combined with compassionate bereavement care is likely to have a positive impact on parents' experiences and improve longer-term outcomes.

TWEETABLE ABSTRACT

Describing baby loss shortly before 24 weeks of gestation as a 'miscarriage' does not prepare parents for labour and birth, seeing their baby and making memories.

102 Process Evaluation Exploring the Delivery and Uptake of Posture and Mobility Training for Staff in Care Homes

Introduction

Provision of care for care home residents with complex needs is challenging. Physiotherapists can play a major role in enhancing the confidence, skills and abilities of care home staff. The Skilful Care Training Package (SCTP) aims to provide staff with an understanding of good posture and training in skilled facilitation of movement. This process evaluation explored barriers and facilitators to delivery and uptake of the SCTP within the context of a feasibility cluster randomised controlled trial (cRCT) in 10 care homes.

Methods

A mixed methods process evaluation, incorporating non-participant observations and interviews, conducted in the five care homes receiving the SCTP intervention. Interviews were audio recorded and transcribed verbatim; resident conversations were captured via a Dictaphone and/or field-notes. Data analysis used the Framework approach.

Results

Fourteen staff training sessions were observed. Interviews with 22 staff and four trainers, and 13 conversations with residents were completed. Five factors influenced delivery and uptake of the SCTP:Organisational factors: strategies to publicise and facilitate access to training improved attendance; a convenient training location and trainer flexibility encouraged attendance and staff engagement.Intervention delivery: a practical participatory element to the training was highly valued; adapting the training to meet the needs of the homes was well-received.Engagement and interaction: relating training to workplace and residents’ experiences engaged staff; high levels of engagement and positive interaction within the training sessions were reported; challenges relating to staff hierarchy affected training delivery in some homes.Intervention content: posture and mobility elements were seen as important; however, some repetition with prior training was highlighted.Training impact: there were indications that staff adopted SCTP techniques. Staff reported an increase in their wellbeing and confidence in movement facilitation; cascade training was reported in some homes.

Conclusions

Training was well-received, and feedback on its impact was largely positive. Practical elements were viewed favourably over classroom-based learning. Intervention content should be revised to optimise focus and avoid overlap with other training.

101 A Posture and Mobility Training Package for Care Home Staff: Results of A Cluster Randomised Controlled Feasibility Trial

Introduction

Provision of care for care home residents with complex needs is challenging. Physiotherapy and activity interventions can improve physical well-being but are often time-limited and resource intensive. A sustainable approach is to enhance the confidence, skills and abilities of care home staff. This trial assessed the feasibility of undertaking a definitive evaluation of the Skilful Care Training Package (SCTP) - a posture and mobility training programme developed by physiotherapists for care home staff.

Methods

A parallel-group, cluster randomised controlled feasibility trial was undertaken in ten care homes in Yorkshire. Five were randomised to receive SCTP, five to usual care. SCTP was delivered by specialist physiotherapists, with the intention of training all direct care staff. Following consent, data were collected from and about residents with restricted mobility (those fulfilling the eligibility criteria) at baseline, three and six months post-randomisation by blinded researchers. Outcome measurement included resident mobility, posture, pain and quality of life. The feasibility of recruitment, retention, data collection and intervention delivery was assessed.

Results

All residents (348) at participating homes were screened for eligibility. 250 were eligible and 146 took part. Follow-up was balanced between arms, with an overall loss-to-follow-up rate of 28.8% at six months. Where residents were available for six-month follow-up, proxy data provision was excellent (97.1% - 100% of expected data). Difficulty collecting data directly from residents was experienced (43.3% of expected data) due to high levels of cognitive impairment. Staff attendance at training met or was close to pre-specified criteria for acceptability in three homes, with 63.0%, 63.6% and 65.8% direct care staff attending all sessions, and &gt;85% attending at least one session across all three homes. However attendance fell short of acceptability in two homes, with only 21.4% and 12.5% staff attending all sessions.

Conclusions

It is feasible to recruit and follow-up residents in a randomised trial comparing SCTP and usual care. Proxy data collection is a successful method, but collection of data from residents is difficult. Intervention delivery success was variable, illustrating heterogeneity between care homes. Future research will be informed by learning from those homes with greater intervention compliance. Work should be undertaken to investigate how best to collect meaningful data from residents.

Heterogeneity of Myc expression in breast cancer exposes pharmacological vulnerabilities revealed through executable mechanistic modeling

Cells with higher levels of Myc proliferate more rapidly and supercompetitively eliminate neighboring cells. Nonetheless, tumor cells in aggressive breast cancers typically exhibit significant and stable heterogeneity in their Myc levels, which correlates with refractoriness to therapy and poor prognosis. This suggests that Myc heterogeneity confers some selective advantage on breast tumor growth and progression. To investigate this, we created a traceable MMTV-Wnt1-driven in vivo chimeric mammary tumor model comprising an admixture of low-Myc- and reversibly switchable high-Myc-expressing clones. We show that such tumors exhibit interclonal mutualism wherein cells with high-Myc expression facilitate tumor growth by promoting protumorigenic stroma yet concomitantly suppress Wnt expression, which renders them dependent for survival on paracrine Wnt provided by low-Myc-expressing clones. To identify any therapeutic vulnerabilities arising from such interdependency, we modeled Myc/Ras/p53/Wnt signaling cross talk as an executable network for low-Myc, for high-Myc clones, and for the 2 together. This executable mechanistic model replicated the observed interdependence of high-Myc and low-Myc clones and predicted a pharmacological vulnerability to coinhibition of COX2 and MEK. This was confirmed experimentally. Our study illustrates the power of executable models in elucidating mechanisms driving tumor heterogeneity and offers an innovative strategy for identifying combination therapies tailored to the oligoclonal landscape of heterogenous tumors.

Visible Machine Learning for Biomedicine

A major ambition of artificial intelligence lies in translating patient data to successful therapies. Machine learning models face particular challenges in biomedicine, however, including handling of extreme data heterogeneity and lack of mechanistic insight into predictions. Here, we argue for "visible" approaches that guide model structure with experimental biology.

Availability of less invasive prenatal, perinatal and paediatric autopsy will improve uptake rates: a mixed-methods study with bereaved parents

Objective

To investigate whether less invasive methods of autopsy would be acceptable to bereaved parents and likely to increase uptake.

Design

Mixed methods study.

Setting

Bereaved parents recruited prospectively across seven hospitals in England and retrospectively through four parent support organisations.

Sample

Eight hundred and fifty‐nine surveys and 20 interviews with bereaved parents.

Methods

Cross‐sectional survey and qualitative semi‐structured telephone interviews.

Main outcome measures

Likely uptake, preferences, factors impacting decision‐making, views on different autopsy methods.

Results

Overall, 90.5% of participants indicated that they would consent to some form of less invasive autopsy [either minimally invasive autopsy (MIA), non‐invasive autopsy (NIA) or both]; 53.8% would consent to standard autopsy, 74.3% to MIA and 77.3% to NIA. Regarding parental preferences, 45.5% preferred MIA, 30.8% preferred NIA and 14.3% preferred standard autopsy. Participants who indicated they would decline standard autopsy but would consent to a less invasive option were significantly more likely to have a lower educational level (odds ratio 0.49; 95% CI 0.35–0.70; P = 0.000062). Qualitative findings suggest that parents value NIA because of the lack of any incision and MIA is considered a good compromise as it enables tissue sampling while easing the parental burden associated with consenting to standard autopsy.

Conclusion

Less invasive methods of autopsy are acceptable alternatives for bereaved parents, and if offered, are likely to increase uptake and improve parental experience. Further health economic, validation and implementation studies are now required to assess the viability of offering these in routine widespread clinical care.

Tweetable abstract

Mixed methods UK study finds less invasive methods of autopsy are acceptable alternatives for bereaved parents, and if offered, are likely to increase uptake and improve parental experience.

Mixed methods UK study finds less invasive methods of autopsy are acceptable alternatives for bereaved parents, and if offered, are likely to increase uptake and improve parental experience.

Increased brain and behavioural susceptibility to portion size in children with loss of control eating

BACKGROUND

Portion size influences intake (i.e. the portion size effect [PSE]), yet determinants of susceptibility to the PSE are unclear.

OBJECTIVE

We tested whether children who reported an episode of loss of control (LOC) eating over the last 3 months would be more susceptible to the PSE and would show differential brain responses to food cues compared with children with no-LOC.

METHODS

Across five sessions, children (n = 47; 7-10 years) consumed four test meals at 100%, 133%, 167% and 200% conditions for portion size and completed a functional magnetic resonance imaging scan while viewing pictures of foods varied by portion size and energy density (ED). Incidence of LOC over the past 3 months was self-reported. Random coefficient models were tested for differences in the shape of the PSE curve by LOC status. A whole-brain analysis was conducted to determine response to food cues during the functional magnetic resonance imaging.

RESULTS

Reported LOC (n = 13) compared with no-LOC (n = 34) was associated with increased susceptibility to the PSE, as evidenced by a positive association with the linear slope (P < 0.005), and negative association with the quadratic slope (P < 0.05) of the intake curve. Children who reported LOC compared with no-LOC showed increased activation in the left cerebellum to small relative to large portions (P < 0.01) and right cerebellum to High-ED relative to Low-ED food cues (P < 0.01).

CONCLUSION

Children who reported LOC were more susceptible to the PSE and showed alterations in food-cue processing in the cerebellum, a hindbrain region implicated in satiety signalling.

Synthesizing Signaling Pathways from Temporal Phosphoproteomic Data

We present a method for automatically discovering signaling pathways from time-resolved phosphoproteomic data. The Temporal Pathway Synthesizer (TPS) algorithm uses constraint-solving techniques first developed in the context of formal verification to explore paths in an interaction network. It systematically eliminates all candidate structures for a signaling pathway where a protein is activated or inactivated before its upstream regulators. The algorithm can model more than one hundred thousand dynamic phosphosites and can discover pathway members that are not differentially phosphorylated. By analyzing temporal data, TPS defines signaling cascades without needing to experimentally perturb individual proteins. It recovers known pathways and proposes pathway connections when applied to the human epidermal growth factor and yeast osmotic stress responses. Independent kinase mutant studies validate predicted substrates in the TPS osmotic stress pathway.

Development and characterisation of a large diameter decellularised vascular allograft

The aims of this study were to develop a biological large diameter vascular graft by decellularisation of native human aorta to remove the immunogenic cells whilst retaining the essential biomechanical, and biochemical properties for the ultimate benefit of patients with infected synthetic grafts. Donor aortas (n = 6) were subjected to an adaptation of a propriety decellularisation process to remove the cells and acellularity assessed by histological analysis and extraction and quantification of total DNA. The biocompatibility of the acellular aortas was determined using standard contact cytotoxicity tests. Collagen and denatured collagen content of aortas was determined and immunohistochemistry was used to determine the presence of specific extracellular matrix proteins. Donor aortas (n = 6) were divided into two, with one half subject to decellularisation and the other half retained as native tissue. The native and decellularised aorta sections were then subject to uniaxial tensile testing to failure [axial and circumferential directions] and suture retention testing. The data was compared using a paired t-test. Histological evaluation showed an absence of cells in the treated aortas and retention of histoarchitecture including elastin content. The decellularised aortas had less than 15 ng mg-1 total DNA per dry weight (mean 94% reduction) and were biocompatible as determined by in vitro contact cytotoxicity tests. There were no gross changes in the histoarchitecture [elastin and collagen matrix] of the acellular aortas compared to native controls. The decellularisation process also reduced calcium deposits within the tissue. The uniaxial tensile and suture retention testing revealed no significant differences in the material properties (p > 0.05) of decellularised aorta. The decellularisation procedure resulted in minimal changes to the biological and biomechanical properties of the donor aortas. Acellular donor aorta has excellent potential for use as a large diameter vascular graft.

Zonally Magnified Oblique Multislice and Non-Zonally Magnified Oblique Multislice DWI of the Cervical Spinal Cord

BACKGROUND AND PURPOSE

The zonally magnified oblique multislice EPI (ZOOM-EPI) diffusion-weighted sequence has been visually shown to provide superior MR diffusion image quality compared with the full-FOV single-shot EPI sequence (non-ZOOM-EPI) in the adult cervical spinal cord. The purpose of this study was to examine the diffusion tensor imaging indices in the normal human cervical spinal cord between ZOOMED and non-ZOOMED DTI acquisitions and determine whether DTI values are comparable between direct and indirect age-matched groups.

MATERIALS AND METHODS

Fifty-four subjects 23-58 years of age (9 direct age-matched and 45 indirect age-matched) were scanned using a 1.5T scanner. Diffusion tensor indices including fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were generated from the DTI dataset. These DTI values were calculated for both ZOOM and non-ZOOM acquisitions and compared at each intervertebral disc level. The variability of the DTI values for ZOOM and non-ZOOM sequences was measured using a coefficient of variation within direct and indirect age-matched controls.

RESULTS

The mean diffusivity, axial diffusivity, and radial diffusivity values obtained along the cervical spinal cord in the age-matched controls showed a significant decrease using the ZOOM sequence (P = .05, P = .002, and P < .001). Mean fractional anisotropy showed a significant increase (P = .04) using the ZOOM sequence. The indirect age-matched controls showed a statistically significant increase in fractional anisotropy (P = .03) and a decrease in mean diffusivity (P = .002), axial diffusivity (P < .001), and radial diffusivity (P = .002) using the ZOOM sequence. Less variability has been shown in DTI using the ZOOM sequence compared with the non-ZOOM sequence in both direct and indirect age groups. The ZOOM sequence exhibited higher SNR (SNR_ZOOM = 22.84 ± 7.59) compared with the non-ZOOM sequence (SNR_non-ZOOM = 19.7 ± 7.05). However, when we used a 2-tailed t test assuming unequal variances, the ZOOM sequence did not demonstrate a statistically significant increase.

CONCLUSIONS

ZOOM DTI acquisition methods provide superior image quality and precision over non-ZOOM techniques and are recommended over conventional full-FOV single-shot EPI DTI for clinical applications in cervical spinal cord imaging.