Abstract 782: Revisiting the angiogenic switch: Host genetic modifiers induce non-productive angiogenesis and inhibit breast cancer

Purpose: Multiple aspects of the tumor microenvironment (TME) impact breast cancer risk, yet the genetic modifiers of the TME are largely unknown, including those that modify tumor vascular formation and function.

Methods: To discover host TME modifiers, we developed a system called the Consomic/Congenic Xenograft Model (CXM). In CXM, human breast cancer cells are orthotopically implanted into genetically-engineered consomic/congenic xenograft host strains that are derived from two parental strains with different susceptibilities to breast cancer. Because the host strain backgrounds are different, whereas the inoculated tumor cells are the same, any phenotypic variation is due to TME modifier(s) on the substituted chromosome (i.e., consomic) or subchromosomal region (i.e., congenic) of the host’s germline DNA. Here, we assessed TME modifiers on rat chromosome 3 (RNO3) that impact growth, angiogenesis, vascular function, and hematogenous metastasis of tumors implanted in the SSIL2Rγ and SS.BN3IL2Rγ CXM strains.

Results: Breast cancer xenografts implanted in SS.BN3IL2Rγ (consomic) had significant inhibition of tumor growth and hematogenous metastasis compared with SSIL2Rγ (parental control), despite a paradoxical increase in the density of blood vessels in the SS.BN3IL2Rγ tumors. We hypothesized that decreased growth of SS.BN3IL2Rγ tumors might be due to nonproductive angiogenesis. To test this possibility, SSIL2Rγ and SS.BN3IL2Rγ tumor vascular function was examined by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), micro-computed tomography (micro-CT), and ex vivo analysis of primary blood endothelial cells; all of which revealed altered vascular function in SS.BN3IL2Rγ tumors compared with SSIL2Rγ. Gene expression analysis also revealed a dysregulated vascular signaling network in SS.BN3IL2Rγ tumors, among which DLL4 was localized to RNO3 and downregulated on the vasculature of SS.BN3IL2Rγ tumors compared with SSIL2Rγ. CXM congenic mapping confirmed that the DLL4 modifier allele is physically linked with breast cancer inhibition by inducing non-productive angiogenesis. Finally, using whole genome sequencing of the germline DNA, we have identified multiple polymorphisms in the DLL4 promoter and a proximal regulatory lncRNA that likely alter DLL4 expression and function.

Conclusions: Collectively, these data suggest that DLL4 can function as a heritable modifier of non-productive angiogenesis that inhibits breast cancer growth and metastasis.

Citation Format: Michael Flister, Cody Plasterer, Shirng-Wern Tsaih, Angela Lemke, Dana Murphy, Amit Joshi, Peter LaViolette, Carmen Bergom. Revisiting the angiogenic switch: Host genetic modifiers induce non-productive angiogenesis and inhibit breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 782. doi:10.1158/1538-7445.AM2017-782

Host genetic modifiers of nonproductive angiogenesis inhibit breast cancer

PURPOSE

Multiple aspects of the tumor microenvironment (TME) impact breast cancer, yet the genetic modifiers of the TME are largely unknown, including those that modify tumor vascular formation and function.

METHODS

To discover host TME modifiers, we developed a system called the Consomic/Congenic Xenograft Model (CXM). In CXM, human breast cancer cells are orthotopically implanted into genetically engineered consomic xenograft host strains that are derived from two parental strains with different susceptibilities to breast cancer. Because the genetic backgrounds of the xenograft host strains differ, whereas the inoculated tumor cells are the same, any phenotypic variation is due to TME-specific modifier(s) on the substituted chromosome (consomic) or subchromosomal region (congenic). Here, we assessed TME modifiers of growth, angiogenesis, and vascular function of tumors implanted in the SS^IL2Rγ and SS.BN3^IL2Rγ CXM strains.

RESULTS

Breast cancer xenografts implanted in SS.BN3^IL2Rγ (consomic) had significant tumor growth inhibition compared with SS^IL2Rγ (parental control), despite a paradoxical increase in the density of blood vessels in the SS.BN3^IL2Rγ tumors. We hypothesized that decreased growth of SS.BN3^IL2Rγ tumors might be due to nonproductive angiogenesis. To test this possibility, SS^IL2Rγ and SS.BN3^IL2Rγ tumor vascular function was examined by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), micro-computed tomography (micro-CT), and ex vivo analysis of primary blood endothelial cells, all of which revealed altered vascular function in SS.BN3^IL2Rγ tumors compared with SS^IL2Rγ. Gene expression analysis also showed a dysregulated vascular signaling network in SS.BN3^IL2Rγ tumors, among which DLL4 was differentially expressed and co-localized to a host TME modifier locus (Chr3: 95-131 Mb) that was identified by congenic mapping.

CONCLUSIONS

Collectively, these data suggest that host genetic modifier(s) on RNO3 induce nonproductive angiogenesis that inhibits tumor growth through the DLL4 pathway.

Reliable and developmentally appropriate study end points are needed to achieve drug development for treatment of pediatric pulmonary arterial hypertension

OBJECTIVE

To identify suitable end points and surrogates for pediatric pulmonary arterial hypertension (PAH) as the lack of developmentally appropriate end point and clinical trials contribute to the unmet medical need.

STUDY DESIGN

Reviewed the efficacy end points and surrogates for all trials (1995 to 2013) that were submitted to the Food and Drug Administration (FDA) to support the approval of PAH therapy and conducted literature search.

RESULTS

An increase in the 6 min walking distance (6MWD) was used as a primary end point in 8/9 adult PAH trials. This end point is not suitable for infants and young children because of performance limitations and lack of control data. One adult PAH trial used time to the first morbidity or mortality event as a primary end point, which could potentially be used in pediatric PAH trials. In the sildenafil pediatric PAH trial, the change in pulmonary vascular resistance index or mean pulmonary artery pressure was used as a surrogate for the 6MWD to assess exercise capacity. However, two deaths and three severe adverse events during the catheterizations made this an unacceptably high-risk surrogate. The INOmax persistent pulmonary hypertension of the newborn trial used a reduction in initiation of extracorporeal membrane oxygenation treatment as a primary end point, which is not feasible for other pediatric PAH trials. A Literature review revealed none of the existing noninvasive markers are fully validated as surrogates to assess PAH efficacy and long-term safety.

CONCLUSIONS

For pediatric PAH trials, clinical end points are acceptable, and novel validated surrogates would be helpful. FDA seeks collaboration with academia, industry and parents to develop other suitable and possibly more efficient efficacy end points to facilitate pediatric PAH drug development.

Suppression of Emittance Growth Using a Shaped Cold Atom Electron and Ion Source

We demonstrate precise control of charged particle bunch shape with a cold atom electron and ion source to create bunches with linear and, therefore, reversible Coulomb expansion. Using ultracold charged particles enables detailed observation of space-charge effects without loss of information from thermal diffusion, unambiguously demonstrating that shaping in three dimensions can result in a marked reduction of Coulomb-driven emittance growth. We show that the emittance growth suppression is accompanied by an increase in bunch focusability and brightness, improvements necessary for the development of sources capable of coherent single-shot ultrafast electron diffraction of noncrystalline objects, with applications ranging from femtosecond chemistry to materials science and rational drug design.

Prospective comparison of outcome after treatment for triple-negative and non-triple-negative breast cancer

INTRODUCTION

Triple-negative breast cancers (TNBC) are associated with a poor prognosis owing to an aggressive phenotype. We aimed to carry out a prospective study comparing management strategies and response to therapy in TNBC and non-TNBC patients.

METHODS

Data were obtained from a prospectively maintained database of patients treated for breast cancer.

RESULTS

A total of 142 TNBC and 142 age-, stage- and NPI-matched non-TNBC patients were treated. The difference in overall survival between the 2 groups was statistically significant (77% of TNBC patients alive at a mean follow-up of 32 months, versus 92% of non-TNBC patients at a mean follow-up of 38 months, P = 0.0 Log rank test). This survival difference was found to be independent of NPI (P = 0.0 Log rank test). Locoregional recurrence rates were similar between TNBC patients who were treated with wide local excision versus mastectomy (P = 0.449 Log rank test). A significant difference in survival was noted between TNBC patients who responded differentially to neoadjuvant chemotherapy (P = 0.035 Log rank test).

CONCLUSION

Patients with TNBC have adverse outcomes despite aggressive treatment. The development of effective targeted therapies is essential for this breast cancer subtype.

Disorder-induced heating of ultracold neutral plasmas created from atoms in partially filled optical lattices

We quantify the disorder-induced heating (DIH) of ultracold neutral plasmas (UCNPs) created from cold atoms in optical lattices with partial filling fractions, using a conservation of energy model involving the spatial correlations of the initial state and the equation of state in thermal equilibrium for a one-component plasma. We show, for experimentally achievable filling fractions, that the ionic Coulomb coupling parameter could be increased to a degree comparable to other proposed DIH-mitigation schemes. Molecular dynamics simulations were performed with compensation for finite-size and periodic boundary effects, which agree with calculations using the model. Reduction of DIH using optical lattices will allow for the study of strongly coupled plasma physics using low-density, low-temperature, laboratory-based plasmas, and lead to improved brightness in UCNP-based cold electron and ion beams, where DIH is otherwise a fundamental limitation to beam focal sizes and diffraction imaging capability.

The Development of Intrinsic and Extrinsic Motivational Orientation in Normal and Disabled Readers

As an adjunct to her effectance motivation model, Harter (1978) has developed an intrinsic-extrinsic orientation scale that would appear to have particular relevance for the learning-disabled child. This article reports scale results obtained from a Canadian sample of 368 reading-disabled and normal children in grades 3-7. Developmental data indicated that both groups of children became more intrinsically oriented as rated by the two informational subscales, Judgment and Criteria. Developmental trends for the motivational subscales of Challenge, Curiosity, and Mastery were less clear. The disabled readers did not differ particularly from normals in regard to the informational scales. Thus, until after 4 years of schooling, their disability in reading does not seem to have affected them adversely. The total score rather than the subscale scores for the three motivational subscales and the total for the two informational subscales are recommended for the assessment of extrinsic-intrinsic orientation.

T regulatory cell phenotypes in peripheral blood and bronchoalveolar lavage from non-asthmatic and asthmatic subjects

BACKGROUND

An unresolved issue in T regulatory cells' cell biology is the lack of consensus on phenotypic markers that accurately define the natural Treg (nTreg) population.

OBJECTIVES

To examine nTreg frequency and functional capacity in healthy controls and their frequency in asthmatic subjects using three different phenotypic strategies. We hypothesized that phenotypically different nTreg are quantitatively and functionally different.

METHODS

Thirty-four healthy, non-asthmatic and 17 asthmatic subjects were studied. Three nTreg phenotypes were defined as follows: nTreg1 (CD4(+) CD25(+) Foxp3(+) ), nTreg2 (CD4(+) CD25(+) CD127(low) Foxp3(+) ), and nTreg3 (CD4(+) CD25(high) Foxp3(+) ). The flow cytometric determination of nTreg frequency in peripheral blood (PB) and bronchoalveolar lavage (BAL) was performed using fluorescently labelled antibodies. Peripheral blood nTreg functional capacity was assessed using a CFSE-based suppression assay.

RESULTS

There was a significantly lower frequency of PB nTreg3 compared to nTreg2 and nTreg1 (P < 0.05). Both nTreg2 and nTreg3 had a significantly greater suppressive capacity than nTreg1 at T responder (Tresp) to nTreg ratios of 16 : 1 up to 1 : 1 (P < 0.01). Asthmatics exhibited a significantly lower PB nTreg3 and nTreg1 frequency than healthy controls (P < 0.05). There were no differences between healthy controls and asthmatic subjects when comparing BAL nTreg frequency.

CONCLUSIONS AND CLINICAL RELEVANCE

Phenotypically different nTreg subsets are quantitatively and functionally different and are variably observed in asthma. The CD4(+) CD25(high) Foxp3(+) phenotype was the least frequent, but demonstrated the greatest suppression, and was significantly lower in PB of asthmatic subjects. Consequently, it is imperative that nTreg phenotypes be clearly defined and that the interpretation of their frequency and function be phenotype specific.

Inflammatory Pseudotumour of the Caecum: A Case Report

Inflammatory pseudotumors of the caecum are uncommon. They pose problems with diagnosis. We report on a 35 year old female who presented with clinical signs of acute appendicitis. Intra-operatively, a caecal tumour was found with normal appendix and multiple enlarged mesenteric lymph nodes. A right hemicolectomy was performed. Histopathology findings revealed an inflammatory mass with abundant fibroblast proliferation with associated collagen formation, infiltrating bowel wall and pericaecal adipose tissue. She recovered well and was discharged home 5 days post-operatively. A t present, she is free of symptoms.

Six-year follow-up study of combined type ADHD from childhood to young adulthood: Predictors of functional impairment and comorbid symptoms

BACKGROUND

ADHD in childhood is associated with development of negative psychosocial and behavioural outcomes in adults. Yet, relatively little is known about which childhood and adulthood factors are predictive of these outcomes and could be targets for effective interventions. To date follow-up studies have largely used clinical samples from the United States with children ascertained at baseline using broad criteria for ADHD including all clinical subtypes or the use of DSM III criteria.

AIMS

To identify child and adult predictors of comorbid and psychosocial comorbid outcomes in ADHD in a UK sample of children with DSM-IV combined type ADHD.

METHOD

One hundred and eighteen adolescents and young adults diagnosed with DSM-IV combined type ADHD in childhood were followed for an average of 6years. Comorbid mental health problems, drug and alcohol use and police contact were compared for those with persistent ADHD, sub-threshold ADHD and population norms taken from the Adult Psychiatric Morbidity Study 2007. Predictors included ADHD symptomology and gender.

RESULTS

Persistent ADHD was associated with greater levels of anger, fatigue, sleep problems and anxiety compared to sub-threshold ADHD. Comorbid mental health problems were predicted by current symptoms of hyperactivity-impulsivity, but not by childhood ADHD severity. Both persistent and sub-threshold ADHD was associated with higher levels of drug use and police contact compared to population norms.

CONCLUSIONS

Young adults with a childhood diagnosis of ADHD showed increased rates of comorbid mental health problems, which were predicted by current levels of ADHD symptoms. This suggests the importance of the continuing treatment of ADHD throughout the transitional years and into adulthood. Drug use and police contact were more common in ADHD but were not predicted by ADHD severity in this sample.

Epigenetic Control of the Vasopressin Promoter Explains Physiological Ability to Regulate Vasopressin Transcription in Dehydration and Salt Loading States in the Rat

The synthesis of arginine vasopressin (AVP) in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus is sensitive to increased plasma osmolality and a decreased blood volume, and thus is robustly increased by both dehydration (increased plasma osmolality and decreased blood volume) and salt loading (increased plasma osmolality). Both stimuli result in functional remodelling of the SON and PVN, a process referred to as functional-related plasticity. Such plastic changes in the brain have recently been associated with altered patterns of DNA methylation at CpG (cytosine-phosphate-guanine) residues, a process considered to be important for the regulation of gene transcription. In this regard, the proximal Avp promoter contains a number of CpG sites and is recognised as one of four CpG islands for the Avp gene, suggesting that methylation may be regulating Avp transcription. In the present study, we show that, in an immortalised hypothalamic cell line 4B, the proximal Avp promoter is highly methylated, and treatment of these cells with the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine to demethylate DNA dramatically increases basal and stimulated Avp biosynthesis. We report no changes in the expression of DNA methyltransferases, Dnmt1 and Dnmt3a, whereas there is decreased expression of the demethylating enzyme ten-eleven-translocation 2, Tet2, in the SON by dehydration and salt loading. We found higher methylation of the SON Avp promoter in dehydrated but not salt-loaded rats. By analysis of individual CpG sites, we observed hypomethylation, hypermethylation and no change in methylation of specific CpGs in the SON Avp promoter of the dehydrated rat. Using reporter gene assays, we show that mutation of individual CpGs can result in altered Avp promoter activity. We propose that methylation of the SON Avp promoter is necessary to co-ordinate the duel inputs of increased plasma osmolality and decreased blood volume on Avp transcription in the chronically dehydrated rat.

Characteristics of prisoners with neurodevelopmental disorders and difficulties

BACKGROUND

Previous studies have found high rates of attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID) within the criminal justice system (CJS). However, little is understood about prisoners with neurodevelopmental disorders and difficulties (NDD) or their needs. This study aimed to identify prisoners with NDD and compare their characteristics with prisoners without NDD on a range of socio-demographic and social functioning measures.

METHOD

This was a descriptive, cross-sectional study carried out using face-to-face interviews with 240 participants in a London Category C prison. Standardised tools were used to assess prisoners for ADHD, ASD and ID.

RESULTS

The study identified 87 prisoners who screened positive for one or more type of NDD. Participants with NDD were significantly younger and more likely to be single [(odds ratio) OR = 2.1], homeless (OR = 3.4) or unemployed (OR = 2.6) before they came into prison. They also had poorer educational achievements that those without NDD. Over 80% of those with NDD had a previous conviction or imprisonment.

CONCLUSIONS

The findings confirm the presence of significant numbers of people with NDD in a male prison. Services across the CJS are required for this group; specifically, there is a need for raised awareness among those working in the CJS to improve the recognition of offenders with NDD. Services in the community need to work with individuals with NDD who are at risk of offending, targeting those who are homeless, unemployed and have poor employment opportunities.

Abstract P2-01-04: A method for comprehensive genomic analysis of cell free DNA

Circulating tumor DNA (ctDNA) is released from tumor tissue into the blood, carries tumor specific genetic alterations, and can be analyzed through noninvasive "liquid biopsy" approaches to identify genetic alterations in cancer patients. Liquid biopsies offer a considerable advantage as they may eliminate the need for invasive tissue biopsies and allow for the detection of alterations in multiple metastatic lesions throughout the course of therapy. However, the fraction of ctDNA obtained from a blood sample is often very low (&lt;1.0%) and can be difficult to detect. Additionally, most methods to evaluate circulating tumor DNA (ctDNA) interrogate single hot spot mutations or few genetic alterations. The next generation of ctDNA assays must interrogate multiple gene regions from a single sample with high precision and accuracy and need to evaluate all forms of actionable genomic alterations including point mutations, amplifications, and translocations. To address these issues, we have developed a ctDNA approach called PlasmaSelect to detect somatic sequence mutations, amplifications and translocations at low allele frequencies in the circulation of cancer patients. Utilizing digital genomic approaches, PlasmaSelect achieves high sensitivity and specificity while interrogating &gt;250,000 nucleotides spanning 63 well-established cancer genes. In addition to sequence mutations in the entire coding region of 18 genes and the exons of 40 genes that are frequently mutated in cancer, PlasmaSelect also performs a comprehensive genomic analysis of amplifications in 57 genes and translocations in 10 genes significant in cancer tumorigenesis. To evaluate the PlasmaSelect approach, we performed dilution series using tumor-derived DNA, containing well-characterized somatic mutations, in the presence of wild-type DNA. PlasmaSelect was able to detect genetic alterations with high specificity and a lower level of detection of 0.10% for sequence mutations and translocations, as well as a focal amplification of ERBB2 with a lower level of detection of 0.20%. We evaluated the clinical utility of PlasmaSelect for detection of genetic alterations in the plasma and matched tissue biopsy specimens from late stage cancer patients. These analyses demonstrated high concordance between the somatic sequence mutations, amplifications, and translocations identified in the tumor sample and those identified directly in the plasma, including alterations in both driver genes as well as those related to acquired resistance to targeted therapies. PlasmaSelect provides a non-invasive platform to enable liquid biopsy detection of clinically relevant genetic alterations across a large number of genomic loci.

Citation Format: Parpart-Li S, Angiuoli SV, Chesnick B, Galens K, Jones S, Kadan M, Kann L, Lytle K, Murphy D, Nesselbush M, Phallen J, Riley D, Shukla M, Zhang T, Husain H, Velculescu V, Diaz, Jr LA, Sausen M. A method for comprehensive genomic analysis of cell free DNA. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-01-04.

Increasing the Brightness of Cold Ion Beams by Suppressing Disorder-Induced Heating with Rydberg Blockade

A model for the equilibrium coupling of an ion system with varying initial hard-sphere Rydberg blockade correlations is used to quantify the suppression of disorder-induced heating in Coulomb-expanding cold ion bunches. We show that bunches with experimentally achievable blockade parameters have an emittance reduced by a factor of 2.6 and increased focusability and brightness compared to a disordered bunch. Demonstrating suppression of disorder-induced heating is an important step in the development of techniques for the creation of beam sources with sufficient phase-space density for ultrafast, single-shot coherent diffractive imaging.

A practice research study concerning homeless service user involvement with a programme of social support work delivered in a specialized psychological trauma service

ACCESSIBLE SUMMARY

Homeless persons are known to be highly vulnerable to psychological trauma, in events triggering periods of homelessness and the considerable social isolation and adversity suffered when homeless. This study provides an account of how mental health support work is experienced by homeless service users when it is informed by a person-centred, non-directive approach and implemented by trainee health and social care professionals under the auspices of a specialized psychological trauma service. The study draws upon material gathered from interviews with service users domiciled in supported housing for homeless persons and support workers who practiced on the programme. The service users who participated in the study valued support work that combined practical and relational elements, but would have preferred a longer-term involvement. They also spoke of feelings of disconnection and estrangement from others including their peers in supported housing. The support worker participants valued the flexibility they had when working on the programme to tailor their intervention to service users' individual needs. Practice implications of the study are discussed. These include the need to minimize barriers to accessing support, facilitate informal time between professionals and homeless service users, and manage intervention endings sensitively when temporary staffing arrangements are in place.

ABSTRACT

Homeless people are a population known to be highly vulnerable to trauma, in triggering events to becoming homeless and the considerable social isolation, discrimination, and adversity suffered when homeless. Currently, there is a paucity of research into mental health service delivery to homeless persons and the influence it imparts in individual lives. This article presents a qualitative 'practice research' study into a pilot programme of social support work delivered in a specialized psychological trauma service to homeless service users. The programme was grounded in a non-directive, person-centred approach and staffed by student social workers. The study aim was to explore the support work programme as it was received by service users domiciled in supported housing for homeless persons, encompassing experiencing the programme, worker-service user engagement and contextual influences bearing upon positive outcomes. Narrative interviews gathered the impressions of service users and support workers and the data arising from these interviews was analysed thematically. Service user participants valued support work that combined practical and relational elements, but would have preferred a longer-term involvement. They also spoke of feelings of disconnection and estrangement from their peers in the supported accommodation and their families. The worker participants valued the flexibility of person-centred work tailored to service users' individual needs and echoed service user concerns around the short-term nature of their involvement. Psychiatric nurses carrying out, or supervising, mental health support work with homeless service users should be mindful of the potential impact of temporary staffing arrangements on continuity of care. They should also consider how working from a person-centred perspective and addressing client's practical needs may aid in developing rapport and trust with homeless service users.

The meaning of a high plasma free haemoglobin: retrospective review of the prevalence of haemolysis and circuit thrombosis in an adult ECMO centre over 5 years

AIMS

In adults requiring extracorporeal membrane oxygenation (ECMO), we wanted to determine; i) the frequency of elevated plasma free haemoglobin (PFHb), ii) the reasons for circuit changes and iii) whether elevated PFHb was associated with higher in-hospital mortality.

MATERIALS AND METHODS

Patients requiring ECMO between January 2010 and August 2014 were identified from a prospectively collected ECMO database. Their scanned medical records and pathology results were reviewed. Relevant patient, biochemical and circuit data were collected on an Excel spreadsheet and analysed using Stata 13 (StataCorp, College Station, TX). The patients were analysed in three groups, depending on their peak PFHb during ECMO: 'Normal PFHb' (<0.1 g/L), 'Low level PFHb' (0.1 - 0.5 g/L), 'High level PFHb' (>0.5 g/L).

MAIN RESULTS

There were 184 ECMO runs (56 VV, 128 VA) - 61 'Normal PFHb', 99 'Low level PFHb', 24 'High level PFHb'. Circuit thrombosis (pump, oxygenator) or haemolysis requiring exchanges were significantly more common in VV ECMO compared to VA ECMO - 23.21% (13/56) vs. 0.78% (1/128), p<0.001. Elevated PFHb was associated with a longer duration of haemofiltration (p<0.001) and ECMO support (p<0.001). In-hospital mortality rates for the 'Normal PFHb', 'Low level PFHb' and 'High level PFHb' groups were 16.39% (10/61), 30.30% (30/99) and 37.50% (9/24), respectively, p=0.067.

CONCLUSION

Elevated PFHb values during adult ECMO were common. Severe haemolysis or thrombosis requiring circuit changes were uncommon and occurred almost exclusively on VV ECMO. There was a non-statistically significant increase in in-hospital mortality with elevated PFHb and studies of larger registry data may clarify the prognostic value of PFHb in adult patients.

Disordered breathing during sleep and exercise in idiopathic pulmonary fibrosis and the role of biomarkers

BACKGROUND AND OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) patients report fatigue, possibly reflecting sleep disturbance, but little is known about sleep-related changes. We compared ventilation and gas exchange during sleep and exercise in a cohort of IPF patients, and evaluated associations with selected biological markers.

METHODS

Twenty stable IPF patients (aged 67.9 ± 12.3 [SD]) underwent overnight polysomnography following an acclimatization night. Cardiopulmonary exercise testing was performed and inflammatory markers measured including TNF-α, IL-6, CXCL8, C-C motif ligand 18 (CCL-18) and C-reactive protein (CRP) RESULTS: Nine patients had sleep-disordered breathing (SDB) with an apnea-hypopnea frequency (AHI) ≥ 5/h, but only two had Epworth sleepiness score ≥ 10, thus having an obstructive sleep apnea syndrome. Sleep quality was poor. Transcutaneous carbon dioxide tension (PtcCO2) rose by 2.56 ± 1.59 kPa overnight (P = 0.001), suggesting hypoventilation. Oxygen saturation (SaO2) was lower during sleep than exercise (P < 0.01), and exercise variables correlated with resting pulmonary function. CCL-18 and CRP levels were elevated and correlated with PtcCO2 rise during sleep (P < 0.05). CCL-18 negatively correlated with diffusion capacity of carbon monoxide (DLCO), arterial oxygen (PaO2) and mean arterial carbon dioxide (PaCO2) (P < 0.05) and CRP negatively correlated with DLCO, PaO2, sleep SaO2 and oxygen uptake (VO2) during exercise (P < 0.05).

CONCLUSIONS

IPF patients desaturate more during sleep than exercise; thus, nocturnal pulse oxymetry could be included in clinical assessment. CCL-18 and CRP levels correlate with physiological markers of fibrosis.

Clinically relevant heterotopic ossification after elbow fracture surgery: a risk factors study

BACKGROUND

Heterotopic ossification (HO) is a common complication of elbow fracture surgery that can significantly impair function and range of motion (ROM). Whereas numerous studies have assessed HO after hip trauma or replacement surgery, few data have been reported on the prevalence and risk factors of HO after elbow fractures.

HYPOTHESIS

Our objective was to investigate the prevalence and risk factors of clinically relevant HO after elbow fracture surgery under the hypothesis that the ability to identify high-risk patients would improve treatment tailoring and assist in meeting patient expectations.

MATERIALS AND METHODS

We retrospectively included consecutive patients who had surgery for elbow injuries between January 2007 and December 2011. Patient demographics, operative details, and radiographs were reviewed.

RESULTS

Of 124 elbows in 122 patients, 38 (30.6%) had HO and 26 (21%) clinically relevant HO. The prevalence of clinically relevant HO was highest in floating elbow injury, followed by combined olecranon and radial head fractures, types A and B distal humerus fractures, and terrible triad injury. By multiple logistic regression, factors that independently predicted clinically relevant HO were fracture-dislocation (OR, 4.87; 95%CI, 1.78-13.29; P=0.002) and longer time to surgery (P<0.05). Of the 26 patients with clinically relevant HO, 6 (23%) eventually required revision elbow surgery to improve ROM.

DISCUSSION

HO of the elbow occurred in almost one-third of our patients with surgically treated elbow fractures. Fracture-dislocation of the elbow and longer time to surgery independently predicted HO responsible for ROM loss. Clinically relevant HO was associated with significant morbidity.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Challenges to delivery of isoniazid preventive therapy in a cohort of children exposed to tuberculosis in Timor-Leste

OBJECTIVES

To evaluate the number and geographic location of children aged <5 years exposed to sputum smear-positive tuberculosis (TB) in Timor-Leste, to determine the proportion evaluated for isoniazid preventive therapy (IPT) and to review the programmatic challenges present in delivering IPT to this cohort.

METHODS

A total of 256 consecutive sputum smear-positive TB index cases diagnosed at Bairo Pite Clinic between August 2013 and July 2014 were interviewed about places of residence and household contacts <5 years of age in the 3 months preceding diagnosis. Attendance of these contacts for screening and the outcome of screening were recorded prospectively.

RESULTS

The majority (225 of 256, 88%) of index cases resided in Dili, but 73 of 225 (32%) of these also had a second address outside the capital. A total of 255 contacts were identified; 172 of 255 (67%) of whom lived in Dili district and 83 of 255 (33%) of whom resided in remote districts. Only 66 of 255 (26%) contacts attended for evaluation for IPT, of whom 46 of 255 (18%) started IPT and nine of 255 (3.5%) were diagnosed with TB. Attendance was significantly less likely when the index case was not the parent of the child contact.

CONCLUSIONS

Sputum smear-positive pulmonary TB cases frequently result in household exposure of children <5 years in Timor-Leste, and provision of IPT is suboptimal. Contacts are located in diverse and distant locations. Further studies to delineate access barriers to IPT and review programmatic models that will facilitate IPT scale up in Timor-Leste are needed.

Barriers and facilitators to dog walking in New England

Dog walking may increase physical activity among dogs and their owners. Understanding barriers and facilitators to walking the dog is critical to developing interventions to increase dog walking. This study aimed to confirm previously identified barriers and facilitators of dog walking, and to identify unique factors that may be relevant to dog walking in cities with variable weather. This mixed methods study used focus groups to identify barriers and facilitators associated with dog walking and a survey to examine which factors were associated with dog walking. Focus group participants described barriers, such as lack of time, weather, lack of places to walk and the dog's bad behaviour. Facilitators included enjoyment, dog walking norms (defined as the participant's perception of how much the veterinarian, other dog owners, and their family think they should walk the dog), and socialisation opportunities. A hierarchical regression analysis of survey data revealed that the participant's perception of dog walking norms was associated with increased frequency and duration of dog walking, while weather, work and family commitment barriers were associated with a reduced frequency and duration of dog walking. Family, community and veterinarian dog walking norms, inclement weather, and lack of time due to work obligations emerged as important correlates of dog walking. Interventions that aim to increase physical activity by encouraging dog walking may benefit from incorporating strategies that address facilitators (family support) and barriers (time and weather) to walking the dog.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Overexpression of corticotropin releasing factor in the central nucleus of the amygdala advances puberty and disrupts reproductive cycles in female rats

Prolonged exposure to environmental stress activates the hypothalamic-pituitary-adrenal (HPA) axis and generally disrupts the hypothalamic-pituitary-gonadal axis. Because CRF expression in the central nucleus of the amygdala (CeA) is a key modulator in adaptation to chronic stress, and central administration of CRF inhibits the hypothalamic GnRH pulse generator, we tested the hypothesis that overexpression of CRF in the CeA of female rats alters anxiety behavior, dysregulates the HPA axis response to stress, changes pubertal timing, and disrupts reproduction. We used a lentiviral vector to increase CRF expression site specifically in the CeA of preweaning (postnatal day 12) female rats. Overexpression of CRF in the CeA increased anxiety-like behavior in peripubertal rats shown by a reduction in time spent in the open arms of the elevated plus maze and a decrease in social interaction. Paradoxically, puberty onset was advanced but followed by irregular estrous cyclicity and an absence of spontaneous preovulatory LH surges associated with proestrous vaginal cytology in rats overexpressing CRF. Despite the absence of change in basal corticosterone secretion or induced by stress (lipopolysaccharide or restraint), overexpression of CRF in the CeA significantly decreased lipopolysaccharide, but not restraint, stress-induced suppression of pulsatile LH secretion in postpubertal ovariectomized rats, indicating a differential stress responsivity of the GnRH pulse generator to immunological stress and a potential adaptation of the HPA axis to chronic activation of amygdaloid CRF. These data suggest that the expression profile of this key limbic brain CRF system might contribute to the complex neural mechanisms underlying the increasing incidence of early onset of puberty on the one hand and infertility on the other attributed to chronic stress in modern human society.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.