Wellbeing, emotional response and stress among lay responders dispatched to suspected out-of-hospital cardiac arrests

Introduction

The recent 2021 European Resuscitation Council guidelines strongly advocate systems for smartphone-aided dispatch of lay volunteers to out-of-hospital cardiac arrests (OHCAs) to perform CPR and bring automated external defibrillators. Systems alike have been implemented in nearly half of all the European countries and are emerging in around the world. This study aimed to investigate the emotional responses, post-traumatic stress reactions and levels of wellbeing among smartphone-alerted lay responders dispatched to cases of suspected OHCAs.

Methods

Participants rated their emotional responses online, at 90 minutes and at 4–6 weeks after an incident. Level of emotional response was measured in two dimensions: “activation” – from deactivation to activation, and “valence” – from unpleasantness to pleasantness. At 4–6 weeks, WHO wellbeing index and level of post-traumatic stress (PTSD) were also rated. Lay responders were stratified by level of exposure: (Un-exp): unexposed, (Exp-1): tried to reach, and (Exp-2): reached the suspected OHCA.

Results

Altogether, 886 (26%) unexposed and 1389 (64%) exposed responders completed the survey. “Activation” was elevated in the exposed groups: Un-exp: 6.7, Exp-1: 7.4 and Exp-2: 7.5, (p<0.001) and “valence” was highest in the Un-exp group: 6.5, vs. Exp-1: 6.3, and Exp-2: 6.1, (p<0.001). Mean scores for PTSD was below clinical cutoff, Un-exp: 10.4, vs. Exp-1: 8.8 and Exp-2: 9.2 (p=0.007). Wellbeing index showed no differences, Un-exp: 77.7, Exp-1: 77.8 and Exp-2: 78.2 (p=0.963).

Conclusion

Laypersons responding to smartphone alerts to suspected OHCAs rated the experience as high-energy and mostly positive. No harm to lay responders was seen. The responding groups had low post-traumatic stress scores, and high-level general wellbeing at follow-up.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Region Stockholm

Ultra-high field magnetic resonance imaging parameter mapping in the posterior horn of ex vivo human menisci

OBJECTIVE

To investigate the relationship between meniscus magnetic resonance (MR) relaxation parameters and meniscus degradation through quantitative imaging of ex vivo posterior horns of menisci from subjects with and without knee osteoarthritis (OA).

DESIGN

We sampled medial and lateral menisci from ten medial compartment knee OA patients (mean age 63 years) undergoing total knee replacement and from ten deceased donors (references, mean age 51 years). MR relaxation parameters T2*, T2 and T1 of the posterior horn were measured at a 9.4 T scanner. Comparisons were made between OA patients and references (with adjustment for age) as well as between medial and lateral menisci from the same knees.

RESULTS

Mean values (standard deviation) of mean T2* were 13 (3.8), 6.9 (2.3), 7.2 (1.9) and 7.2 (1.7) ms for the medial and lateral patient menisci and the medial and lateral reference menisci, respectively. Corresponding values were 17 (3.7), 9.0 (2.2), 12 (4) and 9.0 (1.3) ms for T2 and 1810 (150), 1630 (30), 1580 (90) and 1560 (50) ms for T1. All three relaxation times were significantly longer in medial OA menisci compared to the other groups. Among medial reference menisci, relaxation times (mainly T1) tended to increase with age.

CONCLUSIONS

MR relaxation times T2*, T2 and T1 in the posterior horn are longer in the medial menisci of patients with end-stage medial compartment knee OA compared to the corresponding lateral menisci and to reference menisci. The meniscus seems to undergo intrasubstance alterations related to both OA and ageing.

Identification and Use of Personalized Genomic Markers for Monitoring Circulating Tumor DNA

Digital PCR techniques are ideally suited for accurately quantifying trace amounts of target DNA sequences, such as tumor-derived mutant DNA that is present in the blood circulation of patients with cancer. Here, we describe an approach marrying low-coverage whole-genome sequencing of tumor tissues, to enumerate chromosomal rearrangement breakpoints, together with droplet digital PCR (ddPCR)-based personalized rearrangement assays to cost-effectively monitor circulating tumor DNA levels at multiple time-points during the clinical course. The method is generally applicable to essentially any cancer patient, as all cancers harbor unstable genomes, and may have uses for measuring minimal residual disease, response to therapy, and early detection of metastasis.

Emotional distress as a predictor of statin non-adherence among Swedish first-time myocardial infarction patients, 2006-2013

BACKGROUND

Emotional distress (depression and anxiety) has been known to affect mortality after a myocardial infarction (MI). One possible mechanism is through medication non-adherence. Few studies have investigated the link between statin adherence and emotional distress, and results are not consistent. We aimed to explore whether emotional distress affects adherence among first-time MI patients younger than 75years old receiving a prescription for the first time.

METHODS

We identified first-MI individuals younger than 75years from the SWEDEHEART national quality registers discharged with a statin prescription. The main exposure was the anxiety/depression portion of the EQ-5D from Interview 1 (6-10weeks post-MI) and Interview 2 (12-14months post-MI). We calculated adherence from the Swedish Prescribed Drugs Register during three observation periods (OP): [1] Interview 1 to Interview 2, [2] one year post Interview 2, and [3] two years post Interview 1.

RESULTS

Emotional distress at Interview 1 was not associated with statin adherence for OP1 (RR: 0.99, 95% CI: 0.98, 1.01). Emotional distress at Interview 2 was associated with lower adherence one year later (RR: 0.95, 95% CI: 0.93, 0.98). Emotional distress at Interview 1 was associated with a small decrease in adherence in the complete OP for adherence (RR: 0.98, 95% CI: 0.96, 0.99).

CONCLUSION

Emotional distress was marginally, but independently, associated with lower adherence to statin two years after the MI. Our study suggests that emotional distress may be an important factor for long-term statin adherence, and, thus, may play a clinically important role in long-term outcome.

Interconnectivity imaged in three dimensions: Nano-particulate silica-hydrogel structure revealed using electron tomography

We have used Electron Tomography (ET) to reveal the detailed three-dimensional structure of particulate hydrogels, a material category common in e.g. controlled release, food science, battery and biomedical applications. A full understanding of the transport properties of these gels requires knowledge about the pore structure and in particular the interconnectivity in three dimensions, since the transport takes the path of lowest resistance. The image series for ET were recorded using High-Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM). We have studied three different particulate silica hydrogels based on primary particles with sizes ranging from 3.6nm to 22nm and with pore-size averages from 18nm to 310nm. Here, we highlight the nanostructure of the particle network and the interpenetrating pore network in two and three dimensions. The interconnectivity and distribution of width of the porous channels were obtained from the three-dimensional tomography studies while they cannot unambiguously be obtained from the two-dimensional data. Using ET, we compared the interconnectivity and accessible pore volume fraction as a function of pore size, based on direct images on the nanoscale of three different hydrogels. From this comparison, it was clear that the finest of the gels differentiated from the other two. Despite the almost identical flow properties of the two finer gels, they showed large differences concerning the accessible pore volume fraction for probes corresponding to their (two-dimensional) mean pore size. Using 2D pore size data, the finest gel provided an accessible pore volume fraction of over 90%, but for the other two gels the equivalent was only 10-20%. However, all the gels provided an accessible pore volume fraction of 30-40% when taking the third dimension into account.

Size and property bimodality in magnetic nanoparticle dispersions: single domain particles vs. strongly coupled nanoclusters

The widespread use of magnetic nanoparticles in the biotechnical sector puts new demands on fast and quantitative characterization techniques for nanoparticle dispersions. In this work, we report the use of asymmetric flow field-flow fractionation (AF4) and ferromagnetic resonance (FMR) to study the properties of a commercial magnetic nanoparticle dispersion. We demonstrate the effectiveness of both techniques when subjected to a dispersion with a bimodal size/magnetic property distribution: i.e., a small superparamagnetic fraction, and a larger blocked fraction of strongly coupled colloidal nanoclusters. We show that the oriented attachment of primary nanocrystals into colloidal nanoclusters drastically alters their static, dynamic, and magnetic resonance properties. Finally, we show how the FMR spectra are influenced by dynamical effects; agglomeration of the superparamagnetic fraction leads to reversible line-broadening; rotational alignment of the suspended nanoclusters results in shape-dependent resonance shifts. The AF4 and FMR measurements described herein are fast and simple, and therefore suitable for quality control procedures in commercial production of magnetic nanoparticles.

Cognitive reserve lessens the burden of white matter lesions on executive functions in bipolar disorder

BACKGROUND

The concept of cognitive reserve (CR) hypothesizes that intellectually stimulating activities provide resilience against brain pathology/disease. Whereas brain abnormalities and cognitive impairment are frequently reported in bipolar disorder (BD), it is unknown whether the impact of brain alterations can be lessened by higher CR in BD.

METHOD

We tested if higher CR would reduce the influence of total volumes of deep white matter hypointensities (WMH), ventricular cerebrospinal fluid (CSF), and prefrontal cortex on memory, executive, and attention/speed functions in patients with BD (n = 75). Linear regression models with interaction terms for CR and brain volumes were applied to directly test if CR reduces the influence of brain pathology on cognitive domains.

RESULTS

CR reduced the influence of total volumes of deep WMH (β = -0.38, Q = 0.003) and ventricular CSF (β = -41, Q = 006) on executive functions.

CONCLUSIONS

The interactions between CR and total volumes of deep WMH/ventricular CSF appear to account for executive functioning in BD. The results suggest that the concept of CR is applicable in BD. Higher reserve capacity in BD alters the relationship between brain pathology and clinical presentation.

Targeted sequencing of BRCA1 and BRCA2 across a large unselected breast cancer cohort suggests that one-third of mutations are somatic

We carried out targeted sequencing of BRCA1/2 in an unselected cohort of patients diagnosed with primary breast cancer within a population without strong founder mutations. Eleven percent of cases harbored a germline or somatic BRCA1/2 mutation, and the ratio of germline versus somatic mutation was 2 : 1. This has implications for treatment, genetic counseling, and interpretation of tumor-only testing.

Background

A mutation found in the BRCA1 or BRCA2 gene of a breast tumor could be either germline or somatically acquired. The prevalence of somatic BRCA1/2 mutations and the ratio between somatic and germline BRCA1/2 mutations in unselected breast cancer patients are currently unclear.

Patients and methods

Paired normal and tumor DNA was analyzed for BRCA1/2 mutations by massively parallel sequencing in an unselected cohort of 273 breast cancer patients from south Sweden.

Results

Deleterious germline mutations in BRCA1 (n = 10) or BRCA2 (n = 10) were detected in 20 patients (7%). Deleterious somatic mutations in BRCA1 (n = 4) or BRCA2 (n = 5) were detected in 9 patients (3%). Accordingly, about 1 in 9 breast carcinomas (11%) in our cohort harbor a BRCA1/2 mutation. For each gene, the tumor phenotypes were very similar regardless of the mutation being germline or somatically acquired, whereas the tumor phenotypes differed significantly between wild-type and mutated cases. For age at diagnosis, the patients with somatic BRCA1/2 mutations resembled the wild-type patients (median age at diagnosis, germline BRCA1: 41.5 years; germline BRCA2: 49.5 years; somatic BRCA1/2: 65 years; wild-type BRCA1/2: 62.5 years).

Conclusions

In a population without strong germline founder mutations, the likelihood of a BRCA1/2 mutation found in a breast carcinoma being somatic was ∼1/3 and germline 2/3. This may have implications for treatment and genetic counseling.

Serial monitoring of circulating tumor DNA in patients with primary breast cancer for detection of occult metastatic disease

Metastatic breast cancer is usually diagnosed after becoming symptomatic, at which point it is rarely curable. Cell-free circulating tumor DNA (ctDNA) contains tumor-specific chromosomal rearrangements that may be interrogated in blood plasma. We evaluated serial monitoring of ctDNA for earlier detection of metastasis in a retrospective study of 20 patients diagnosed with primary breast cancer and long follow-up. Using an approach combining low-coverage whole-genome sequencing of primary tumors and quantification of tumor-specific rearrangements in plasma by droplet digital PCR, we identify for the first time that ctDNA monitoring is highly accurate for postsurgical discrimination between patients with (93%) and without (100%) eventual clinically detected recurrence. ctDNA-based detection preceded clinical detection of metastasis in 86% of patients with an average lead time of 11 months (range 0–37 months), whereas patients with long-term disease-free survival had undetectable ctDNA postoperatively. ctDNA quantity was predictive of poor survival. These findings establish the rationale for larger validation studies in early breast cancer to evaluate ctDNA as a monitoring tool for early metastasis detection, therapy modification, and to aid in avoidance of overtreatment.

Mutation Screening of 1,237 Cancer Genes across Six Model Cell Lines of Basal-Like Breast Cancer

Basal-like breast cancer is an aggressive subtype generally characterized as poor prognosis and lacking the expression of the three most important clinical biomarkers, estrogen receptor, progesterone receptor, and HER2. Cell lines serve as useful model systems to study cancer biology in vitro and in vivo. We performed mutational profiling of six basal-like breast cancer cell lines (HCC38, HCC1143, HCC1187, HCC1395, HCC1954, and HCC1937) and their matched normal lymphocyte DNA using targeted capture and next-generation sequencing of 1,237 cancer-associated genes, including all exons, UTRs and upstream flanking regions. In total, 658 somatic variants were identified, of which 378 were non-silent (average 63 per cell line, range 37–146) and 315 were novel (not present in the Catalogue of Somatic Mutations in Cancer database; COSMIC). 125 novel mutations were confirmed by Sanger sequencing (59 exonic, 48 3’UTR and 10 5’UTR, 1 splicing), with a validation rate of 94% of high confidence variants. Of 36 mutations previously reported for these cell lines but not detected in our exome data, 36% could not be detected by Sanger sequencing. The base replacements C/G>A/T, C/G>G/C, C/G>T/A and A/T>G/C were significantly more frequent in the coding regions compared to the non-coding regions (OR 3.2, 95% CI 2.0–5.3, P<0.0001; OR 4.3, 95% CI 2.9–6.6, P<0.0001; OR 2.4, 95% CI 1.8–3.1, P<0.0001; OR 1.8, 95% CI 1.2–2.7, P = 0.024, respectively). The single nucleotide variants within the context of T[C]T/A[G]A and T[C]A/T[G]A were more frequent in the coding than in the non-coding regions (OR 3.7, 95% CI 2.2–6.1, P<0.0001; OR 3.8, 95% CI 2.0–7.2, P = 0.001, respectively). Copy number estimations were derived from the targeted regions and correlated well to Affymetrix SNP array copy number data (Pearson correlation 0.82 to 0.96 for all compared cell lines; P<0.0001). These mutation calls across 1,237 cancer-associated genes and identification of novel variants will aid in the design and interpretation of biological experiments using these six basal-like breast cancer cell lines.

Contralateral breast cancer can represent a metastatic spread of the first primary tumor: determination of clonal relationship between contralateral breast cancers using next-generation whole genome sequencing

Introduction

By convention, a contralateral breast cancer (CBC) is treated as a new primary tumor, independent of the first cancer (BC1). Although there have been indications that the second tumor (BC2) sometimes may represent a metastatic spread of BC1, this has never been conclusively shown. We sought to apply next-generation sequencing to determine a “genetic barcode” for each tumor and reveal the clonal relationship of CBCs.

Methods

Ten CBC patients with detailed clinical information and available fresh frozen tumor tissue were studied. Using low-coverage whole genome DNA-sequencing data for each tumor, chromosomal rearrangements were enumerated and copy number profiles were generated. Comparisons between tumors provided an estimate of clonal relatedness for tumor pairs within individual patients.

Results

Between 15–256 rearrangements were detected in each tumor (median 87). For one patient, 76 % (68 out of 90) of the rearrangements were shared between BC1 and BC2, highly consistent with what has been seen for true primary-metastasis pairs (>50 %) and thus confirming a common clonal origin of the two tumors. For most of the remaining cases, BC1 and BC2 had similarly low overlap as unmatched randomized pairs of tumors from different individuals, suggesting the CBC to represent a new independent primary tumor.

Conclusion

Using rearrangement fingerprinting, we show for the first time with certainty that a contralateral BC2 can represent a metastatic spread of BC1. Given the poor prognosis of a generalized disease compared to a new primary tumor, these women need to be identified at diagnosis of CBC for appropriate determination of treatment. Our approach generates a promising new method to assess clonal relationship between tumors. Additional studies are required to confirm the frequency of CBCs representing metastatic events.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0608-x) contains supplementary material, which is available to authorized users.

Abstract 4805: Whole genome sequencing of primary breast cancers and matched distant metastases

Metastatic disease is the main cause of death for breast cancer patients, but it is still unclear whether primary tumor characteristics are predictive of the metastasis phenotype. Our aim was to investigate, by analyzing chromosomal structural variation, the clonal similarities between primary breast tumors and their matched distant metastases. For 11 patients, we performed low-coverage (∼10x) whole-genome sequencing on 11 primary breast tumors and 13 matched distant metastases to enumerate chromosomal rearrangements. The tumor genomes (n = 24) harbored a median of 85 (range 18-405) chromosomal rearrangements per tumor, with a median of 82 (26-310) in primaries compared to 87 (18-405) in distant metastases. Similarity between tumors was assessed based on presence or absence of chromosomal rearrangements. Concordance between matched primaries and distant metastases from the same patient was high, with a median of 89% rearrangements being shared (range 61-100%). Nearly all of the rearrangements were patient-specific, with very little overlap when comparing all possible pairings of tumors from different patients (median 3%). The tumors exhibited different genomic patterns of rearrangements: some carried events scattered throughout the genome while other tumors had events in densely clustered foci - chromothripsis-like hotspots - at a few chromosomal locations. Irrespective of the type of rearrangement profile of the tumor genomes, the patterns were highly conserved between the primary tumor and metastasis from the same patient, although in general metastases acquired additional rearrangement events. Our study suggests that analysis of structural variation in tumor genomes could be useful for identifying tumor origin, facilitating cancer detection via measurement of rearrangements in circulating tumor DNA, and estimating degree of relatedness between primary tumors and metastases. Moreover, our finding that distant metastases have a close clonal relationship to the primary tumor at the level of chromosomal structure is most consistent with chromosomal rearrangements being early events in breast cancer progression that remain stable during the development from a primary tumor to its distant metastasis.

Citation Format: Man-Hung Tang, Malin Dahlgren, Christian Brueffer, Christof Winter, Yilun Chen, Eleonor Olsson, Martin Sjöström, Pär-Ola Bendahl, Emma Niméus-Malmström, Lao H. Saal, Åke Borg, Sofia K. Gruvberger-Saal. Whole genome sequencing of primary breast cancers and matched distant metastases. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4805. doi:10.1158/1538-7445.AM2015-4805

Cancer-associated fibroblasts expressing CXCL14 rely upon NOS1-derived nitric oxide signaling for their tumor-supporting properties

Cancer-associated fibroblasts (CAF) stimulate tumor growth and metastasis. Signals supporting CAF function are thus emerging as candidate therapeutic targets in the tumor microenvironment. The chemokine CXCL14 is a potent inducer of CAF protumorigenic functions. This study is aimed at learning how the protumoral functions of CXCL14-expressing CAF are maintained. We found that the nitric oxide synthase NOS1 is upregulated in CXCL14-expressing CAF and in fibroblasts stimulated with CXCL14. Induction of Nos1 was associated with oxidative stress and occurred together with activation of NRF2 and HIF1α signaling in CXCL14-expressing CAF. Genetic or pharmacologic inhibition of NOS1 reduced the growth of CXCL14-expressing fibroblasts along with their ability to promote tumor formation following coinjection with prostate or breast cancer cells. Tumor analysis revealed reduced macrophage infiltration, with NOS1 downregulation in CXCL14-expressing CAF and lymphangiogenesis as a novel component of CXCL14-promoted tumor growth. Collectively, our findings defined key components of a signaling network that maintains the protumoral functions of CXCL14-stimulated CAF, and they identified NOS1 as intervention target for CAF-directed cancer therapy.

Molecular and genetic diversity in the metastatic process of melanoma

Diversity between metastatic melanoma tumours in individual patients is known; however, the molecular and genetic differences remain unclear. To examine the molecular and genetic differences between metastatic tumours, we performed gene-expression profiling of 63 melanoma tumours obtained from 28 patients (two or three tumours/patient), followed by analysis of their mutational landscape, using targeted deep sequencing of 1697 cancer genes and DNA copy number analysis. Gene-expression signatures revealed discordant phenotypes between tumour lesions within a patient in 50% of the cases. In 18 of 22 patients (where matched normal tissue was available), we found that the multiple lesions within a patient were genetically divergent, with one or more melanoma tumours harbouring 'private' somatic mutations. In one case, the distant subcutaneous metastasis of one patient occurring 3 months after an earlier regional lymph node metastasis had acquired 37 new coding sequence mutations, including mutations in PTEN and CDH1. However, BRAF and NRAS mutations, when present in the first metastasis, were always preserved in subsequent metastases. The patterns of nucleotide substitutions found in this study indicate an influence of UV radiation but possibly also DNA alkylating agents. Our results clearly demonstrate that metastatic melanoma is a molecularly highly heterogeneous disease that continues to progress throughout its clinical course. The private aberrations observed on a background of shared aberrations within a patient provide evidence of continued evolution of individual tumours following divergence from a common parental clone, and might have implications for personalized medicine strategies in melanoma treatment.

Estimation of mass thickness response of embedded aggregated silica nanospheres from high angle annular dark-field scanning transmission electron micrographs

In this study, we investigate the functional behaviour of the intensity in high-angle annular dark field scanning transmission electron micrograph images. The model material is a silica particle (20 nm) gel at 5 wt%. By assuming that the intensity response is monotonically increasing with increasing mass thickness of silica, an estimate of the functional form is calculated using a maximum likelihood approach. We conclude that a linear functional form of the intensity provides a fair estimate but that a power function is significantly better for estimating the amount of silica in the z-direction. The work adds to the development of quantifying material properties from electron micrographs, especially in the field of tomography methods and three-dimensional quantitative structural characterization from a scanning transmission electron micrograph. It also provides means for direct three-dimensional quantitative structural characterization from a scanning transmission electron micrograph.

Evaluation of skin displacement in the equine neck

Kinematic studies, using reflective skin markers, are commonly used to investigate equine joint motion in equitation science and for rehabilitation purposes. In order to interpret the registrations accurately, the degree of skin displacement has been described for the limbs and back, but not yet for the neck. The aim of the present study was to measure sagittal plane skin displacement in the equine neck. Radiopaque skin markers were applied to the skin over the first six cervical vertebrae of six healthy horses. Latero-lateral radiographs were taken in three standardised neck positions in the sagittal plane: control (horizontal neck), ‘on the bit’ and ‘nose to carpus’. The scales of the images were normalised and calculation of skin displacement was done by use of a coordinate system, dividing the displacement along an x-axis parallel to the vertebra's longitudinal axis and a y-axis perpendicular to the x-axis. Mixed models analysis was employed to study the differences in distances in x- and y-directions, and statistical significance was set to PÃ0.05. Between control and ‘nose to carpus’ positions, there were significant differences in skin marker locations, relative to the underlying vertebrae, in the x-direction for C1-6, and in y-direction for C3-6. Between normal and ‘on the bit’ positions, there were significant difference in both x- and y-directions for C6. Differences in marker locations along x- and y-axes, respectively, were 3±9 mm and 44±14 mm. The outcome of this study indicates that skin displacement should be considered when investigating equine neck motion with skin marker methodology.

Anisotropic two-dimensional electron gas at the LaAlO₃/SrTiO₃ (110) interface

The observation of a high-mobility two-dimensional electron gas between two insulating complex oxides, especially LaAlO₃/SrTiO₃, has enhanced the potential of oxides for electronics. The occurrence of this conductivity is believed to be driven by polarization discontinuity, leading to an electronic reconstruction. In this scenario, the crystal orientation has an important role and no conductivity would be expected, for example, for the interface between LaAlO₃ and (110)-oriented SrTiO₃, which should not have a polarization discontinuity. Here we report the observation of unexpected conductivity at the LaAlO₃/SrTiO₃ interface prepared on (110)-oriented SrTiO₃, with a LaAlO₃-layer thickness-dependent metal-insulator transition. Density functional theory calculation reveals that electronic reconstruction, and thus conductivity, is still possible at this (110) interface by considering the energetically favourable (110) interface structure, that is, buckled TiO₂/LaO, in which the polarization discontinuity is still present. The conductivity was further found to be strongly anisotropic along the different crystallographic directions with potential for anisotropic superconductivity and magnetism, leading to possible new physics and applications.

Although LaAlO₃ and SrTiO₃ are both insulators, when they are brought together at a (100) interface, a highly conducting two-dimensional electron gas forms between them. Annandi et al. show that this also happens at a (110) interface, counter to expectations that it should not.

Abstract LB-77: Measurement of tumor-specific chromosomal rearrangements in serial blood samples to monitor breast cancer burden and detect occult metastasis

Malignant cells release into the blood circulation their naked DNA, a potential biomarker containing tumor-specific chromosomal rearrangements. These tumor-derived rearrangements can be detected and quantified in cell-free blood plasma for information on minimal residual disease, treatment response, and detection of occult metastasis. Advances in high-throughput sequencing now allows for timely and affordable enumeration of tumor-specific chromosomal rearrangements in tumor types that have no pathognomonic DNA changes, such as breast cancer. We investigated whether individualized tumor-specific chromosomal rearrangements could meet clinical sensitivity and specificity criteria to serve as robust breast cancer biomarkers in serial blood plasma samples. To this end, we studied a retrospective cohort of 35 patients with early breast cancer for which frozen primary tumor specimens were available and blood plasma samples had been biobanked at diagnosis (prior to surgery) and at regular time intervals during the clinical course. Nine patients were relapse-free at 7-years follow-up and 26 patients had metastatic disease detected clinically between 1.1 to 5.7 years after diagnosis. HiSeq paired-end sequencing of the primary tumor DNA to 1.8 to 8-fold genome coverage (average 3.9x) identified 27 to 417 chromosomal rearrangements per tumor (average 134). For rearrangements confirmed to be somatic, droplet digital PCR (ddPCR) assays were designed for their quantification in the DNA isolated from cell-free blood plasma. Tumor and matched normal DNA were used as positive and negative controls. In the ddPCR analysis of 15 patients thus far, monitoring 2 to 6 rearrangements per patient, our method exhibits 100% sensitivity and 100% specificity for post-surgical molecular detection of tumor-specific rearranged DNA in the plasma from patients with and without confirmed clinical recurrence. Furthermore, the time-point of our molecular detection of recurrent disease preceded symptoms and clinical detection in nearly all patients (an average lead time of 9 months; range 0 to 28 months). Our results demonstrate that identification of tumor-specific chromosomal rearrangements and subsequent serial analysis of genomic aberrations in blood is a highly sensitive and specific method for monitoring tumor burden and relapse in early breast cancer. Given that the cost of such analyses is comparable to medical procedures such as CT scans, our approach shows great promise as a clinical test for routine cancer management.

Citation Format: Eleonor Olsson, Christof Winter, Anthony George, Yilun Chen, Man-Hung Eric Tang, Malin Dahlgren, Ralph Schulz, Mårten Fernö, Carsten Rose, Jillian Howlin, Christian Ingvar, Lisa Rydén, Åke Borg, Sofia K. Gruvberger-Saal, Helena Jernström, Lao H. Saal. Measurement of tumor-specific chromosomal rearrangements in serial blood samples to monitor breast cancer burden and detect occult metastasis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-77. doi:10.1158/1538-7445.AM2013-LB-77

STC1 expression by cancer-associated fibroblasts drives metastasis of colorectal cancer

Platelet-derived growth factor (PDGF) receptor signaling is a major functional determinant of cancer-associated fibroblasts (CAF). Elevated expression of PDGF receptors on stromal CAFs is associated with metastasis and poor prognosis, but mechanism(s) that underlie these connections are not understood. Here, we report the identification of the secreted glycoprotein stanniocalcin-1 (STC1) as a mediator of metastasis by PDGF receptor function in the setting of colorectal cancer. PDGF-stimulated fibroblasts increased migration and invasion of cocultured colorectal cancer cells in an STC1-dependent manner. Analyses of human colorectal cancers revealed significant associations between stromal PDGF receptor and STC1 expression. In an orthotopic mouse model of colorectal cancer, tumors formed in the presence of STC1-deficient fibroblasts displayed reduced intravasation of tumor cells along with fewer and smaller distant metastases formed. Our results reveal a mechanistic basis for understanding the contribution of PDGF-activated CAFs to cancer metastasis.

Electrical and structural properties of ABO3/SrTiO3 interfaces

Electrical transport and microstructure of interfaces between nm-thick films of various perovskite oxides grown by pulsed laser deposition (PLD) on TiO2- terminated SrTiO3 (STO) substrates are compared. LaAlO3/STO and KTaO3/STO interfaces become quasi-2DEG after a critical film thickness of 4 unit cell layers. The conductivity survives long anneals in oxygen atmosphere. LaMnO3/STO interfaces remain insulating for all film thicknesses and NdGaO3/STO interfaces are conducting but the conductivity is eliminated after oxygen annealing. Medium-energy ion spectroscopy and scanning transmission electron microscopy detect cationic intermixing within several atomic layers from the interface in all studied interfaces. Our results indicate that the electrical reconstruction in the polar oxide interfaces is a complex combination of different mechanisms, and oxygen vacancies play an important role.

CD44 isoforms are heterogeneously expressed in breast cancer and correlate with tumor subtypes and cancer stem cell markers

Background

The CD44 cell adhesion molecule is aberrantly expressed in many breast tumors and has been implicated in the metastatic process as well as in the putative cancer stem cell (CSC) compartment. We aimed to investigate potential associations between alternatively spliced isoforms of CD44 and CSCs as well as to various breast cancer biomarkers and molecular subtypes.

Methods

We used q-RT-PCR and exon-exon spanning assays to analyze the expression of four alternatively spliced CD44 isoforms as well as the total expression of CD44 in 187 breast tumors and 13 cell lines. ALDH1 protein expression was determined by IHC on TMA.

Results

Breast cancer cell lines showed a heterogeneous expression pattern of the CD44 isoforms, which shifted considerably when cells were grown as mammospheres. Tumors characterized as positive for the CD44⁺/CD24^- phenotype by immunohistochemistry were associated to all isoforms except the CD44 standard (CD44S) isoform, which lacks all variant exons. Conversely, tumors with strong expression of the CSC marker ALDH1 had elevated expression of CD44S. A high expression of the CD44v2-v10 isoform, which retain all variant exons, was correlated to positive steroid receptor status, low proliferation and luminal A subtype. The CD44v3-v10 isoform showed similar correlations, while high expression of CD44v8-v10 was correlated to positive EGFR, negative/low HER2 status and basal-like subtype. High expression of CD44S was associated with strong HER2 staining and also a subgroup of basal-like tumors. Unsupervised hierarchical cluster analysis of CD44 isoform expression data divided tumors into four main clusters, which showed significant correlations to molecular subtypes and differences in 10-year overall survival.

Conclusions

We demonstrate that individual CD44 isoforms can be associated to different breast cancer subtypes and clinical markers such as HER2, ER and PgR, which suggests involvement of CD44 splice variants in specific oncogenic signaling pathways. Efforts to link CD44 to CSCs and tumor progression should consider the expression of various CD44 isoforms.

High white matter lesion load is associated with hippocampal atrophy in mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) is a heterogeneous condition suggested as a prodromal state of Alzheimer's disease (AD) and subcortical vascular dementia (SVD). Recent findings suggest that white matter lesions (WML) may be associated with hippocampal atrophy. The objective of the study was to examine hippocampal and WML volumes in MCI patients and to examine if WML were linked to hippocampal atrophy.

METHODS

The Gothenburg MCI study is a clinically based longitudinal study with biennial clinical assessments. The participants (n = 166) consist of 92 patients with stable MCI, 30 patients with converting MCI, and 44 healthy controls. WML volumes was measured manually using MRIcron. Automated segmentation of hippocampal and total white matter volumes was performed using FreeSurfer.

RESULTS

The patients converting from MCI to dementia had reduced hippocampal volume. Stable MCI patients had fewer WML and converting MCI patients had more WML compared to controls. Hippocampal volume was only correlated to WML volume (ρ = 0.57; p < 0.01) in the quartile (n = 42) with the most WML.

CONCLUSIONS

Hippocampal atrophy is present in both AD and SVD. Hippocampal volume was associated with WML volume only in the high WML quartile, suggesting that the WML volume must reach a threshold before hippocampal atrophy is seen.

FC14-02 - Biological stress markers, executive functions and self-perceived stress in adults with ADHD (attention-deficit /hyperactivity disorder)

Introduction

The management of normal daily tasks may be complicated for adults with ADHD (attention-deficit/hyperactivity disorder) due to executive dysfunctions. ADHD may thus increase the risk of chronic stress in everyday life.

Objective

To study endocrinological and psycho physiological stress markers in adults with ADHD in association to performance in test of executive functions (EF) and self-perceived stress.

Methods

Cardiovascular stress markers were assessed in 30 adults with ADHD with no psychoactive medication, and 30 healthy controls during: (1) non-stress baseline; (2) cognitive stress; and (3) non-stress recovery. The Visual Analogues Scale was used to assess self-perceived stress. Salivary cortisol was measured pre- and post-experiment. To measure stress in everyday life we assessed diurnal cortisol values, stressors and self-ratings of stress.

Results

The group with ADHD showed higher self-perceived stress but attenuated or atypical cardiovascular stress reactivity during experimentally induced stress, and stress reactivity predicted performance in the executive test. Baseline cardiovasular values did not differ from the controls. The diagnosis of ADHD significantly increased the risk of belonging to the group with high post-stress cortisol levels. The two groups were comparable with respect to overall diurnal cortisol levels and rhythm. The ADHD group reported significantly higher self-perceived stress and these values correlated with level of stressors in everyday life.

Conclusions

The overall baseline values in biological stress markers may be comparable between adults with ADHD and healthy controls, while the stress reactivity and recovery pattern may differ between the two groups.

Electrical Properties of Nanocrystalline Tungsten Trioxide

Tungsten oxide is a material of significant interest for applications in several areas. It can, for example, be used as the electrochromic film in smart windows. Tungsten trioxide nanoparticles were produced using an advanced gas evaporation unit in which the tungsten was oxidized in low pressure ambient air. The tungsten trioxide particles were formed via vapor condensation and were deposited by gas deposition technique to avoid coagulation effects. The average size of the primary particles was around 5 nm, depending on the heating power and the pressure. The particles exhibited a body centred cubic structure. The impedance spectrum of particle deposits showed resonance and negative capacitance effects. The correlation between fabrication conditions, structure and impedance spectrum is discussed.

Temperature Dependence of the Electrical Resistivity in Nanocrystalline Gold Films Made by Advanced GaS Deposition

Nanocrystalline thin Au films with grain size 10 - 76 nm have been analyzed regarding the temperature dependence of the electrical resistivity. A sudden change in the power function, ρ α Tn, was found at ∼10 K, where n = 1.7 in the range 5 - 10 K and n = 3.3 in the range 10 - 15 K. This effect disappears after annealing at 773 K for 0.5 h in air at atmospheric pressure. After the annealing the grain size was ∼ 100 nm. This is an indication of interference between electron-phonon scattering and electron-grain boundary scattering in nanocrystalline materials at low temperatures.

The temperature coefficient of resistivity, TCR, increased with increasing grain size at any temperature and the position of the maximum TCR was shifted towards lower temperatures with increasing grain size.

Soft nanostructuring of YBCO Josephson junctions by phase separation

We have developed a new method to fabricate biepitaxial YBa2 Cu3 O7-δ (YBCO) Josephson junctions at the nanoscale, allowing junctions widths down to 100 nm and simultaneously avoiding the typical damage in grain boundary interfaces due to conventional patterning procedures. By using the competition between the superconducting YBCO and the insulating Y2 BaCuO5 phases during film growth, we formed nanometer sized grain boundary junctions in the insulating Y2 BaCuO5 matrix as confirmed by high-resolution transmission electron microscopy. Electrical transport measurements give clear indications that we are close to probing the intrinsic properties of the grain boundaries.

Electron backscattering diffraction and X-ray diffraction studies of interface relationships in Sr3Ru2O7/Sr2RuO4 eutectic crystals

Sr3Ru2O7/Sr2RuO4 eutectic system is investigated by electron backscattering diffraction (EBSD) and X-ray diffraction (XRD). The eutectic growth enables the solidification of the two phases in an ordered lamellar pattern extending along the growth direction, namely the b-axis direction. The eutectic material thus provides in the a-c plane two distinct interfaces having different microstructures with respect to the growth direction. Our analysis shows that, across the inplane c-axis direction (characterized by a poor lattice matching), the b-axis orientation is not constant at the individual interfaces, showing an orientation spread of about 5°. However, across the in-plane a-axis direction (characterized by a good lattice matching), the b-axis orientation does not change within a few tenths of degree (about 0.25°). Such information at nanoscale is also verified on a macroscopic level by standard XRD investigation.

Combination of hippocampal volume and cerebrospinal fluid biomarkers improves predictive value in mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) is a heterogeneous condition, and the prognosis differs within the group. Recent findings suggest that hippocampal volumetry and CSF biomarkers can be used to predict which MCI patients have an underlying neurodegenerative disorder.

OBJECTIVE

To examine the combined predictive value of hippocampal volume and CSF levels of total tau (T-tau) and beta-amyloid(42) (Abeta(42)) in stable and converting MCI patients. The participants (n = 68) included patients with MCI at baseline and who converted to dementia by the time of the 2-year follow-up (n = 21), stable MCI patients (n = 21) and healthy controls (n = 26).

METHODS

The Göteborg MCI study is a clinically based longitudinal study with biannual clinical assessments. Hippocampal volumetry was performed manually, based on data from the 0.5-tesla MRI investigations at baseline. Baseline CSF levels of T-tau and Abeta(42) were measured using commercially available, enzyme-linked immunosorbent assays.

RESULTS

The converting MCI group had significantly smaller left hippocampi, lower CSF Abeta(42) and higher T-tau compared to both the stable MCI group and the healthy controls. Multivariate analysis revealed that a combination of the variables outperformed the prognostic ability of the separate variables.

CONCLUSIONS

Hippocampal volumes supplement the prognostic accuracy of CSF Abeta(42) and T-tau in MCI.

Cationic disorder and phase segregation in LaAlO3/SrTiO3 heterointerfaces evidenced by medium-energy ion spectroscopy

Medium-energy ion spectroscopy (MEIS) has been used to study the depth profile and deduce the distribution of possible cationic substitutions in LaAlO3/SrTiO3 (LAO/STO) heterointerfaces. Analysis of La and Sr peaks in aligned and random MEIS spectra indicates that the surface layers of LAO on an STO substrate are not homogeneous and stoichiometric if the film thickness is less than 4 unit cell layers. This is possibly caused by a redistribution of La and Sr at the interface. Kelvin probe force microscopy reveals an inhomogeneous distribution of the surface potential in a 4 unit cell LAO film, indicating micrometer-sized regions of different compositions. Our findings provide a novel view on the microstructural origin of the electrically conductive interfaces.

Small baseline volume of left hippocampus is associated with subsequent conversion of MCI into dementia: the Göteborg MCI study

BACKGROUND

Earlier studies have reported that hippocampal atrophy can to some extent predict which patients with mild cognitive impairment (MCI) will subsequently convert to dementia, and that converters have an enhanced rate of hippocampal volume loss.

OBJECTIVE

To further validate the hypothesis that hippocampal atrophy predicts conversion from MCI to dementia, to relate baseline hippocampal volume to different forms of dementia, and to investigate the role of hippocampal side differences and rate of volume loss over time.

PATIENTS

The subjects (N=68) include patients with MCI at baseline and progression to dementia at the two-year follow-up (N=21), stable MCI patients (N=21), and controls (N=26). Among the progressing patients, 13 were diagnosed as having AD.

METHODS

The Göteborg MCI study is a clinically based longitudinal study with biannual clinical assessments. Hippocampal volumetry was performed manually on the MRI investigations at baseline and at the two-year follow-up.

RESULTS

Hippocampal volumetry could predict conversion to dementia in both the AD and the non-AD subgroup of converters. Left hippocampal volume in particular discriminated between converting and stable MCI. Cut off points for individual discrimination were shown to be potentially useful. The converting MCI group had a significantly higher rate of hippocampal volume loss as compared to the stable MCI group.

CONCLUSIONS

In MCI patients, hippocampal volumetry at baseline gives prognostic information about possible development of AD and non-AD dementia. Contrary to earlier studies, we found that left hippocampal volume has the best predictive power. Reliable predictions appear to be possible in many individual cases.

The molecular signature of MDS stem cells supports a stem-cell origin of 5q myelodysplastic syndromes

Global gene expression profiling of highly purified 5q-deleted CD34+CD38(-)Thy1+ cells in 5q- myelodysplastic syndromes (MDSs) supported that they might originate from and outcompete normal CD34+CD38(-)Thy1+ hematopoietic stem cells. Few but distinct differences in gene expression distinguished MDS and normal stem cells. Expression of BMI1, encoding a critical regulator of self-renewal, was up-regulated in 5q- stem cells. Whereas multiple previous MDS genetic screens failed to identify altered expression of the gene encoding the myeloid transcription factor CEBPA, stage-specific and extensive down-regulation of CEBPA was specifically observed in MDS progenitors. These studies establish the importance of molecular characterization of distinct stages of cancer stem and progenitor cells to enhance the resolution of stage-specific dysregulated gene expression.

High-resolution genomic profiles of breast cancer cell lines assessed by tiling BAC array comparative genomic hybridization

A BAC-array platform for comparative genomic hybridization was constructed from a library of 32,433 clones providing complete genome coverage, and evaluated by screening for DNA copy number changes in 10 breast cancer cell lines (BT474, MCF7, HCC1937, SK-BR-3, L56Br-C1, ZR-75-1, JIMT1, MDA-MB-231, MDA-MB-361, and HCC2218) and one cell line derived from fibrocystic disease of the breast (MCF10A). These were also characterized by gene expression analysis and found to represent all five recently described breast cancer subtypes using the "intrinsic gene set" and centroid correlation. Three cell lines, HCC1937 and L56BrC1 derived from BRCA1 mutation carriers and MDA-MB-231, were of basal-like subtype and characterized by a high frequency of low-level gains and losses of typical pattern, including limited deletions on 5q. Four estrogen receptor positive cell lines were of luminal A subtype and characterized by a different pattern of aberrations and high-level amplifications, including ERBB2 and other 17q amplicons in BT474 and MDA-MB-361. SK-BR-3 cells, characterized by a complex genome including ERBB2 amplification, massive high-level amplifications on 8q and a homozygous deletion of CDH1 at 16q22, had an expression signature closest to luminal B subtype. The effects of gene amplifications were verified by gene expression analysis to distinguish targeted genes from silent amplicon passengers. JIMT1, derived from an ERBB2 amplified trastuzumab resistant tumor, was of the ERBB2 subtype. Homozygous deletions included other known targets such as PTEN (HCC1937) and CDKN2A (MDA-MB-231, MCF10A), but also new candidate suppressor genes such as FUSSEL18 (HCC1937) and WDR11 (L56Br-C1) as well as regions without known genes. The tiling BAC-arrays constitute a powerful tool for high-resolution genomic profiling suitable for cancer research and clinical diagnostics.

Motor function in subjects with mild cognitive impairment and early Alzheimer's disease

Basic mobility, balance, gait and dual-task performance were characterised in 140 consecutive subjects referred to a multidisciplinary university hospital in a geriatric setting for cognitive symptoms and possible dementia. After completion of an extensive diagnostic evaluation, subjects were classified into four diagnostic categories: no cognitive impairment, mild cognitive impairment, Alzheimer's disease (AD) and other dementia. Mean age was 57 +/- 9.2, 60 +/- 7.3, 68 +/- 9.9 and 64 +/- 10.5, respectively. Data on motor function, medication use and presence of white matter changes were evaluated and compared between the diagnostic groups. Motor function seems to be affected in very mild AD but not in mild cognitive impairment, as assessed with performance-based tests. AD subjects were slowed and had difficulties in dual-task performance requiring concurrently performing a cognitive task while walking.