Sparse interleaved sampling for high resolution focal construct geometry X-ray tomography

We demonstrate interleaved sampling by multiplexing conical subshells within the tomosynthesis and raster scanning a phantom through a 150 kV shell X-ray beam. Each view comprises pixels sampled on a regular 1 mm grid, which is then upscaled by padding with null pixels before tomosynthesis. We show that upscaled views comprising 1% sample pixels and 99% null pixels increase the contrast transfer function (CTF) computed from constructed optical sections from approximately 0.6 line pairs/mm to 3 line pairs/mm. The driver of our method is to complement work concerning the application of conical shell beams to the measurement of diffracted photons for materials identification. Our approach is relevant to time-critical, and dose-sensitive analytical scanning applications in security screening, process control and medical imaging.

POS1314 VALIDATION OF A PEDIATRIC-SPECIFIC ULTRASOUND SCORING SYSTEM FOR THE EVALUATION OF WRIST, FINGER, AND ANKLE SYNOVITIS

Background

Juvenile Idiopathic Arthritis (JIA) is the most common chronic rheumatic disease in children. Clinical evaluation of arthritis is a subjective measurement. Musculoskeletal ultrasound (MSUS) is increasingly being utilized in children. In order to provide objective assessments of arthritis, reliable and validated MSUS scoring systems are needed. Recently, a joint-specific scoring system for the assessment of arthritis of the pediatric ankle, wrist and finger joints were proposed[1, 2].

Objectives

This study aims to further validate the MSUS scoring system for the assessment of finger, wrist, and ankle arthritis

Methods

JIA patients with finger, wrist, and ankle arthritis as per expert clinician evaluation are eligible for this study. A comprehensive wrist, ankle, and finger (2-5th metacarpal and 2-5th proximal interphalangeal joints) MSUS examination by an American College of Rheumatology MSUS certified pediatric rheumatologist is performed an all enroll subjects. MSUS are scored using the semiquantitative (grade 0 to 3) scoring systems previously proposed. A subset of participants receives an MRI with contrast of the targeted joint immediately after MSUS performance. MRI findings are read for presence of synovitis, tendonitis and enthesitis by a pediatric radiologist with expertise on musculoskeletal imaging. For the analysis of the current report, MRIs were classified as having presence or absence of findings of JIA disease based on the pediatric radiologist expert opinion. MSUS were classified as normal (grade 0 and 1) or abnormal (grade 2 and 3). Cohen’s Kappa Coefficient was used to assess the level of agreement between MSUS (normal and abnormal) and MRI with contrast (absence or presence of disease) for each targeted joint. Tetrachoric Correlation was used to assess the strength of the association. Fisher’s Exact test was used to determine statistical significance at p < 0.05 level.

Results

A total of 52 children aged 2 – 18 years old have been enrolled in this study. To date 20 MSUS of the finger(s), 33 MSUS of the wrist, and 43 MSUS of the ankle joints have been collected. Three MRI of the 2-5 fingers (12 fingers total), 6 MRI of the wrist, and 5 MRI of ankle have been obtained through the study. Preliminary results of this effort reveal that for the ankle joint there is moderate agreement (Kappa coefficient 0.53 (confidence interval (CI)=0.14-0.92)) between MRI and US and a strong positive tetrachoric correlation (0.79) (p = 0.03). While the Kappa coefficient for comparing MRI and US finding on wrist joint indicated moderate agreement (Kappa 0.62 [0.15-1.00]) with a strong tetrachoric correlation (0.83) the Fisher’s exact test indicated a trend rather than statistically significant results (p = 0.07). The Kappa coefficient for MCPs and PIPs joints indicated strong agreement between MRI and US (Kappa 0.83 [CI=0.52-1.00] and 0.80 [CI=0.43-1.00] respectively) and were supported by an almost perfect Tetrachoric Correlation of 0.99 (p < 0.01). We anticipate to complete enrollment of subjects by the summer of 2022. Analysis of collected data is underway.

Conclusion

The strong to moderate association of MSUS with contrast-enhanced MRI, suggest that MSUS can provide an objective and accurate assessment of ankle, wrist and finger arthritis at the bedside. Further refinement and validation of these pediatric-specific MSUS scoring systems may support the use of MSUS as a clinical tool and outcome measure in JIA.

References

[1]Vega-Fernandez P, D.R.D., Oberle E, Bukulmez H, Lin C, Shenoi S, Thatayatikom A, Woolnough L, Corbin K, Benham H, Brunner E, Henrickson M, Ballenger L, Haro S, Schutt C, Proulx-Gauthier J, Janow G, Altaye M, Cassedy A, Roth J, Ting T., Novel Ultrasound Image Acquisition Protocol and Scoring System for the Pediatric Ankle [abstract]. Arthritis Rheumatol, 2020. 72.

[2]Vega-Fernandez, P., et al., The MUSICAL pediatric ultrasound examination - a comprehensive, reliable, time efficient assessment of synovitis. Arthritis Care Res (Hoboken), 2021.

Acknowledgements

Project supported by the Center for Clinical & Translational Science & Training (CCTST) at the University of Cincinnati funded by the National Institutes of Health (NIH) Clinical and Translational Science Award (CTSA) program, grant 2UL1TR001425-05A1 and KL2 (2KL2TR001426-05A); and a Diversity and Health Disparities Award from the Cincinnati Children’s Hospital Medical Center.

Disclosure of Interests

None declared

Organic synthesis associated with serpentinization and carbonation on early Mars

Water-rock interactions are relevant to planetary habitability, influencing mineralogical diversity and the production of organic molecules. We examine carbonates and silicates in the martian meteorite Allan Hills 84001 (ALH 84001), using colocated nanoscale analyses, to characterize the nature of water-rock reactions on early Mars. We find complex refractory organic material associated with mineral assemblages that formed by mineral carbonation and serpentinization reactions. The organic molecules are colocated with nanophase magnetite; both formed in situ during water-rock interactions on Mars. Two potentially distinct mechanisms of abiotic organic synthesis operated on early Mars during the late Noachian period (3.9 to 4.1 billion years ago).

Coastal flood risk within a peri-urban area: Sussex Inlet district, SE Australia

The peri-urban interface (PUI) exhibits characteristic qualities of both urban and rural regions, and this complexity has meant that risk assessments and long-term planning for PUI are lagging, despite these areas representing new developing settlement frontiers. This study aims to address this knowledge gap by modifying an existing approach to quantify and assess flood risk. The risk triangle framework was used to map exposure, vulnerability and biophysical variables; however, in a novel application, the risk triangle framework was adapted by presuming that there is a variation in the degree of exposure, vulnerability and biophysical variables. Within Australia and globally, PUIs are often coastal, and flood risk associated with rainfall and coastal inundation poses considerable risk to communities in the PUI; these risks will be further exacerbated should projections of increasing frequency of extreme rainfall events and accelerating sea-level rise eventuate. An indicator-based approach using the risk triangle framework that maps flood hazard, exposure and vulnerability was used to integrate the biophysical and socio-economic flooding risk for communities in PUI of the St Georges Basin and Sussex Inlet catchments of south-eastern Australia. Integrating the flood risk triangle with future scenarios of demographic and climate change, and considering factors that contribute to PUI flood risk, facilitated the identification of planning strategies that would reduce the future rate of increase in flood risk. These planning strategies are useful for natural resource managers and land use planners across Australia and globally, who are tasked with balancing socio-economic prosperity for a changing population, whilst maintaining and enhancing ecosystem services and values. The indicator-based approach used in this study provides a cost-effective first-pass risk assessment and is a valuable tool for decision makers planning for flood risk across PUIs in NSW and globally.

Mangrove sinkholes (cenotes) of the Yucatan Peninsula, a global hotspot of carbon sequestration

Mangroves are among the most carbon-dense ecosystems on the planet. The capacity of mangroves to store and accumulate carbon has been assessed and reported at regional, national and global scales. However, small-scale sampling is still revealing 'hot spots' of carbon accumulation. This study reports one of these hotspots, with one of the largest-recorded carbon stocks in mangroves associated with sinkholes (cenotes) in the Yucatan Peninsula, Mexico. We assessed soil organic carbon (SOC) stocks, sequestration rates and carbon origin of deep peat soils (1 to 6 m). We found massive amounts of SOC up to 2792 Mg C ha-1, the highest value reported in the literature so far. This SOC is primarily derived from highly preserved mangrove roots and has changed little since its deposition, which started over 3220 years ago (±30 BP). Most cenotes are owned by Mayan communities and are threatened by increased tourism and the resulting extraction and pollution of groundwater. These hot spots of carbon sequestration, albeit small in area, require adequate protection and could provide valuable financial opportunities through carbon-offsetting mechanisms and other payments for ecosystem services.

P1943Ambient temperature and seasonal effects on blood pressure in 2.6 million Australians

Background

There is evidence that blood pressure (BP) levels vary considerably from season to season, due principally to variation in ambient temperature. This gives the potential for both under- and over-treatment if BP lowering medications are not varied seasonally, but is not acknowledged in clinical guidelines. We will describe the seasonal variation in BP and assess the association between systolic blood pressure (SBP) and outdoor maximum ambient temperature in Australia.

Methods

The primary care data is an extract from MedicineInsight, a national general practice data program developed and managed by NPS MedicineWise, which extracts deidentified data from almost 10% of all Australian general practices. We included patients aged 30–90 years with at least one BP measure recorded from 1 Jan 2010 to 1 Aug 2017. Australian Bureau of Meteorology daily max temperature is linked by matching observation dates and location to nearest weather station. Decomposition of the mean will determine seasonal variation. Multiple linear regression was used to estimate the associations between max temperature and SBP with adjustment for age, sex, socioeconomic index, current smoking, comorbidities, BP lowering medication use, lipid lowering medication use and year of BP measurement.

Results

The study population includes 2.6 million people, mean age 55 years (standard deviation [SD] 16.3). Fifty-five percent are female, over a third of the cohort reside in New South Wales, and 62.4% reside in major Australian cities. The mean (SD) temperature was 23°C (6.6).

There was a mean (SD) of 7 (11.4) BP measurements per person over the study period, median 3 measures (interquartile range 1–8). A quarter had a history of hypertension, 8% had a history of cardiovascular disease, and 8% had a history of diabetes. Twenty-six percent had at least one prescription for BP lowering therapy.

The average monthly SBP for the cohort demonstrated strong seasonal variation with higher values in winter. The population mean varies by 3mmHg SBP between seasons across Australia, ranging from 1.7mmHg in the Northern Territory to 3.5mmHg in South Australia (range of mean maximum temperature 3°C [30–33] and 14°C [15–29] for the capital cities respectively). Each 10°C increase in max outdoor temperature was associated with a 1.8mmHg [95% CI 1.80–1.83] lower mean SBP. The proportion of people with SBP>140mmHg varied by season, irrespective of age, sex and use of BP lowering treatment. For example, among those treated control rates varied between 70 and 81%, and among those not treated between 78 and 85% (Figure).

Blood pressure seasonality in Australia

Conclusions

BP control rates vary considerably by season. These findings have implications for the reliable diagnosis of hypertension, and suggest seasonal adjustments in treatment should be considered for some patients. The clinical and public health relevance of this phenomenon is expected to increase with increasing climate variability.

Acknowledgement/Funding

National Health and Medical Research Council Australia, National Heart Foundation Australia

Organic synthesis on Mars by electrochemical reduction of CO2

The sources and nature of organic carbon on Mars have been a subject of intense research. Steele et al. (2012) showed that 10 martian meteorites contain macromolecular carbon phases contained within pyroxene- and olivine-hosted melt inclusions. Here, we show that martian meteorites Tissint, Nakhla, and NWA 1950 have an inventory of organic carbon species associated with fluid-mineral reactions that are remarkably consistent with those detected by the Mars Science Laboratory (MSL) mission. We advance the hypothesis that interactions among spinel-group minerals, sulfides, and a brine enable the electrochemical reduction of aqueous CO₂ to organic molecules. Although documented here in martian samples, a similar process likely occurs wherever igneous rocks containing spinel-group minerals and/or sulfides encounter brines.

Converse Smith-Martin cell cycle kinetics by transformed B lymphocytes

Recent studies using direct live cell imaging have reported that individual B lymphocytes have correlated transit times between their G1 and S/G2/M phases. This finding is in contradiction with the influential model of Smith and Martin that assumed the bulk of the total cell cycle time variation arises in the G1 phase of the cell cycle with little contributed by the S/G2/M phase. Here we extend these studies to examine the relation between cell cycle phase lengths in two B lymphoma cell lines. We report that transformed B lymphoma cells undergo a short G1 period that displays little correlation with the time taken for the subsequent S/G2/M phase. Consequently, the bulk of the variation noted for total division times within a population is found in the S/G2/M phases and not the G1 phase. Models that reverse the expected source of variation and assume a single deterministic time in G1 followed by a lag + exponential distribution for S/G2/M fit the data well. These models can be improved further by adopting two sequential distributions or by using the stretched lognormal model developed for primary lymphocytes. We propose that shortening of G1 transit times and uncoupling from other cell cycle phases may be a hallmark of lymphocyte transformation that could serve as an observable phenotypic marker of cancer evolution.

Global patterns of care in advanced stage mycosis fungoides/Sezary syndrome: a multicenter retrospective follow-up study from the Cutaneous Lymphoma International Consortium

BACKGROUND

Advanced-stage mycosis fungoides (MF)/Sézary syndrome (SS) patients are weighted by an unfavorable prognosis and share an unmet clinical need of effective treatments. International guidelines are available detailing treatment options for the different stages but without recommending treatments in any particular order due to lack of comparative trials. The aims of this second CLIC study were to retrospectively analyze the pattern of care worldwide for advanced-stage MF/SS patients, the distribution of treatments according to geographical areas (USA versus non-USA), and whether the heterogeneity of approaches has potential impact on survival.

PATIENTS AND METHODS

This study included 853 patients from 21 specialist centers (14 European, 4 USA, 1 each Australian, Brazilian, and Japanese).

RESULTS

Heterogeneity of treatment approaches was found, with up to 24 different modalities or combinations used as first-line and 36% of patients receiving four or more treatments. Stage IIB disease was most frequently treated by total-skin-electron-beam radiotherapy, bexarotene and gemcitabine; erythrodermic and SS patients by extracorporeal photochemotherapy, and stage IVA2 by polychemotherapy. Significant differences were found between USA and non-USA centers, with bexarotene, photopheresis and histone deacetylase inhibitors most frequently prescribed for first-line treatment in USA while phototherapy, interferon, chlorambucil and gemcitabine in non-USA centers. These differences did not significantly impact on survival. However, when considering death and therapy change as competing risk events and the impact of first treatment line on both events, both monochemotherapy (SHR = 2.07) and polychemotherapy (SHR = 1.69) showed elevated relative risks.

CONCLUSION

This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach.

Realizing the promise of The Partnership for Maternal, Newborn and Child Health

Reflecting on Storeng and Béhague ("Lives in the balance": the politics of integration in the Partnership for Maternal, Newborn and Child Health. Health Policy and Planning Storeng and Béhague (2016).) historical ethnography of the Partnership for Maternal, Newborn and Child Health (PMNCH), this commentary provides a more current account of PMNCH's trajectory since its inception in 2005. It highlights PMNCH's distinct characteristics and how it is positioned to play an instrumental role in the current global health landscape.

Predictors of older drivers' involvement in rapid deceleration events

Rapid deceleration occurs when substantial force slows the speed of a vehicle. Rapid deceleration events (RDEs) have been proposed as a surrogate safety measure. As there is concern about crash involvement of older drivers and the effect of age-related declining visual and cognitive function on driving performance, we examined the relationship between RDEs and older driver's vision, cognitive function and driving confidence, using naturalistic driving measures. Participants aged 75 to 94 years had their vehicle instrumented for 12 months. To minimise the chance of identifying false positives, accelerometer data was processed to identify RDEs with a substantial deceleration of >750 milli-g (7.35m/s²). We examined the incidence of RDEs amongst older drivers, and how this behaviour is affected by differences in age; sex; visual function, cognitive function; driving confidence; and declines over the 12 months. Almost two-thirds (64%) of participants were involved in at least one RDE, and 22% of these participants experienced a meaningful decline in contrast sensitivity during the 12 months. We conducted regression modelling to examine associations between RDEs and predictive measures adjusted for (i) duration of monitoring and (ii) distance driven. We found the rate of RDEs per distance increased with age; although, this did not remain in the multivariate model. In the multivariate model, we found older drivers who experienced a decline in contrast sensitivity over the 12 months and those with lower baseline driving confidence were at increased risk of involvement in RDEs adjusted for distance driven. In other studies, contrast sensitivity has been associated with increased crash involvement for older drivers. These findings lend support for the use of RDEs as a surrogate safety measure, and demonstrate an association between a surrogate safety measure and a decline in contrast sensitivity of older drivers.

Towards new material biomarkers for fracture risk

Osteoporosis is a prevalent bone condition, characterised by low bone mass and increased fracture risk. Currently, the gold standard for identifying osteoporosis and increased fracture risk is through quantification of bone mineral density (BMD) using dual energy X-ray absorption (DEXA). However, the risk of osteoporotic fracture is determined collectively by bone mass, architecture and physicochemistry of the mineral composite building blocks. Thus DEXA scans alone inevitably fail to fully discriminate individuals who will suffer a fragility fracture. This study examines trabecular bone at both ultrastructure and microarchitectural levels to provide a detailed material view of bone, and therefore provides a more comprehensive explanation of osteoporotic fracture risk. Physicochemical characterisation obtained through X-ray diffraction and infrared analysis indicated significant differences in apatite crystal chemistry and nanostructure between fracture and non-fracture groups. Further, this study, through considering the potential correlations between the chemical biomarkers and microarchitectural properties of trabecular bone, has investigated the relationship between bone mechanical properties (e.g. fragility) and physicochemical material features.

Mangrove Sedimentation and Response to Relative Sea-Level Rise

Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions, related primarily to elevation and hydroperiod, influence mangrove distributions; this review considers how these distributions change over time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks, and tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas measurements made using surface elevation tables and marker horizons provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in a continuing decline in their extent throughout the tropics.

Rat Cytomegalovirus Vaccine Prevents Accelerated Chronic Rejection in CMV-Naïve Recipients of Infected Donor Allograft Hearts

Cytomegalovirus accelerates transplant vascular sclerosis (TVS) and chronic rejection (CR) in solid organ transplants; however, the mechanisms involved are unclear. We determined the efficacy of a CMV vaccine in preventing CMV-accelerated rat cardiac allograft rejection in naïve recipients of CMV+ donor hearts. F344 donor rats were infected with RCMV 5 days prior to heterotopic cardiac transplantation into CMV-naïve or H2 O2 -inactivated RCMV-vaccinated Lewis recipients. Recipients of RCMV-infected donor hearts rejected at POD59, whereas vaccinated recipients exhibited a significantly prolonged time to rejection-POD97, similar to recipients of uninfected donor hearts (POD108). Although all of the donor hearts were preinfected, the vaccinated recipients had lower graft and PBMC viral loads at POD 7 compared to unvaccinated controls. Adoptive T cell and passive antibody transfers from vaccinated Lewis rats into naïve recipients demonstrate that both T-cell and B-cell arms of the adaptive immune response provide protection against CMV-accelerated rejection. Similar findings were obtained when testing three different adjuvants in passive transfer experiments. We have determined that the timing of the vaccine prior to transplantation and the specific adjuvant play critical roles in mediating anti-viral responses and promoting graft survival. CMV vaccination prior to transplantation may effectively increase graft survival.

Intra-crystalline protein diagenesis (IcPD) in Patella vulgata. Part I: Isolation and testing of the closed system

This study successfully isolates a fraction of intra-crystalline proteins from shells of the marine gastropod Patella vulgata and assesses the suitability of these proteins for IcPD (Intra-crystalline Protein Diagenesis) geochronology. We discuss the mineralogical composition of this gastropod, investigated for the first time by X-ray diffraction mapping, and use the results to inform our sampling strategy. The potential of the calcitic rim and of a bulk sample (containing both apex and rim) of the shell to act as stable repositories for the intra-crystalline proteins during diagenesis is examined. The composition and the diagenetic behaviour of the intra-crystalline proteins isolated from different locations within the shell are compared, highlighting the necessity of targeting consistent sampling positions. We induced artificial diagenesis of both intra-crystalline and whole-shell proteins by conducting high-temperature experiments in hydrous environment; this allowed us to quantify the loss of amino acids by leaching and therefore evaluate the open- or closed-system behaviour of the different fractions of proteins. The results obtained provide further confirmation that patterns of diagenesis vary according to the protein sequence, structure, and location within or outside the intra-crystalline fraction. As Patella is frequently found in the fossil record, both in archaeological and geological contexts, the application of IcPD geochronology to this biomineral opens up the possibility to obtain reliable age information from a range of sites in different areas of the world.

microRNA biogenesis and turnover in plants

microRNAs (miRNAs) are short RNAs that regulate gene expression in eukaryotes. The biogenesis and turnover of miRNAs determine their spatiotemporal accumulation within tissues. miRNA biogenesis is a multistep process that entails transcription, processing, nuclear export, and formation of the miRNA-ARGONAUTE complex. Factors that perform each of these steps have been identified. Generation of mature miRNAs from primary transcripts, i.e., miRNA processing, is a key step in miRNA biogenesis. Our understanding of miRNA processing has expanded beyond the enzyme that performs the reactions, as more and more additional factors that impact the efficiency and accuracy of miRNA processing are uncovered. In contrast to miRNA biogenesis, miRNA turnover is an important but poorly understood process that contributes to the steady-state levels of miRNAs. Enzymes responsible for miRNA degradation have only recently been identified. This review describes the processes of miRNA maturation and degradation in plants.

Abstract P3-06-28: Use of the MiCK drug-induced apoptosis assay improves clinical outcomes in recurrent breast cancer (BRCA)

Background: The microculture kinetic (MiCK) assay (Correct Chemo™) correlates with outcomes in acute myelocytic leukemia and ovarian cancer (Cancer Research, in press). A prior trial suggested that its use in breast cancer could improve clinical outcomes (Cancer, in press). This study was designed to correlate MiCK assay results with clinical outcomes in recurrent or metastatic BRCA.

Methods: 30 patients with recurrent or metastatic breast cancer in 4 different institutions were evaluated. Each patient (pt) had a BRCA biopsy sent to a central laboratory, tumor cells were purified to over 90% homogeneity, and were then cultured with individual drugs or drug combinations. The induction of apoptosis was measured every five minutes continuously for 48 hours. The amount of apoptosis was expressed in kinetic units (KU), and results were sent to the attending oncologist within 72 hours of submission. Physicians were free to choose any treatment plan for the pts, and were free to add hormonal therapy or biotherapy. Clinical results were evaluated by oncologists using clinical criteria and the results of the MiCK assay were correlated with outcomes of complete (CR) or partial (PR) response, time-to-relapse (TTR), and overall survival (OS).

Results: Median age was 57 years, and number of lines of prior therapy was a median of 2 (range 1–8). Median ECOG performance status was 1. The total number of drugs tested in the assay was a median of 12 (range 3–31). The MiCK assay was used to help select therapy in 22 pts (73%). There was change between drugs originally planned before MiCK assay and drugs used after MiCK in 15 pts (50%). The best therapy from the MiCK assay was used for treatment in 16 pts (53%). In five pts (17%), a single drug was used in place of a combination. Generic drugs were used in place of proprietary drugs in nine pts (30%). Hormonal therapy was added to drugs selected based on the MiCK assay in seven pts (23%), and bio-therapy drugs were added to chemotherapy drugs in eight pts (27%). If the MiCK results were used to help select therapy, eight pts had a CR or PR (27%), compared to 0 pts with CR or PR if MiCK was not used (p = 0.04). If the MiCK assay was used to determine therapy, 17 pts (59%) had a CR, PR or stable disease compared to only 2 pts (6.9%) in whom the MiCK assay was not used (p &lt; 0.01). The TTR was significantly longer if the MiCK assay was used to select chemotherapy, 7.4 months, compared to only 2.2 months if the MiCK assay was not used (p &lt; 0.01). There was a trend toward longer survival if the MiCK assay was used, 16.8 months, compared to 13.1 months if the MiCK assay was not used, but the difference was not statistically significant (p = 0.3). If the best chemotherapy from the MiCK assay was used, there were trends for increased TTR (7.3 vs 3.9 mo if best not used p = 0.13) and increased rate of CR or PR or stable (54% vs 17% p = 0.11).

Conclusions: Use of the MiCK assay to determine chemotherapy was associated with a higher response rate and a longer time to relapse in pts with recurrent or metastatic BRCA. It is possible that OS is also improved, but longer follow up is needed. There was a trend for improved outcomes if the best chemotherapy based on the MiCK assay was used.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-28.

Bone mineral crystallisation kinetics

The kinetics of bone apatite crystallisation are examined using a novel approach to obtain quantitative, direction dependence features such as growth rate and activation energy. X-ray diffraction was employed for analysis of bovine, porcine and 'anorganic' bone specimens. Apatite coherence length was utilised as the independent variable within a Johnson-Mehl-Avrami (JMA) model. A direction averaged crystallisation activation energy of 183 ± 8 kJ mol(-1) was observed for the three bone groups. The Johnson-Mehl-Avrami 'n' exponent decreased with increasing temperature for all bone groups, indicating that apatite crystallisation changes to a diffusion limited process at higher temperatures. The results revealed little evidence to support any organic component 'protective' effect, and, on the contrary indicated that the organic matrix promotes apatite crystallisation.

Monaural conductive hearing loss alters the expression of the GluA3 AMPA and glycine receptor α1 subunits in bushy and fusiform cells of the cochlear nucleus

The impact of conductive hearing loss (CHL), the second most common form of hearing loss, on neuronal plasticity in the central auditory pathway is unknown. After short-term (1 day) monaural earplugging, the GluA3 subunits of the AMPA receptor (AMPAR) are upregulated at auditory nerve synapses on the projection neurons of the cochlear nucleus; glycine receptor α1 (GlyRα1) subunits are downregulated at inhibitory synapses in the same neuronal population. These data suggest that CHL affects receptor trafficking at synapses. We examined the impact of 7 days of CHL on the general expression of excitatory and inhibitory receptors by quantitative biochemistry and immunohistochemistry, using specific antibodies to detect AMPAR subunits (GluA1, GluA2, GluA2/3, and GluA4), GlyRα1, and the GABA(A) receptor subunits β2/3. Following monaural earplugging and an elevation of the hearing threshold by approximately 35 dB, the immunolabeling of the antibody for the GluA2/3 subunits but not the GluA2 subunit increased on bushy cells (BCs) and fusiform cells (FCs) of the ipsilateral ventral and dorsal cochlear nuclei. These same cell types showed a downregulation of the GlyRα1 subunit. Similar results were observed in the contralateral nuclei. The expression levels of GABA(A) β2/3 were unchanged. These findings suggest that, following longer periods of monaural conductive hearing loss, the synthesis and subsequent composition of specific glutamate and glycine receptors in projection neurons and their synapses are altered; these changes may contribute to abnormal auditory processing.

Effects of the interactions of classical swine fever virus Core protein with proteins of the SUMOylation pathway on virulence in swine

Here we have identified host cell proteins involved with the cellular SUMOylation pathway, SUMO-1 (small ubiquitin-like modifier) and UBC9, a SUMO-1 conjugating enzyme that interact with classical swine fever virus (CSFV) Core protein. Five highly conserved lysine residues (K179, K180, K220, K221, and K246) within the CSFV Core were identified as putative SUMOylation sites. Analysis of these interactions showed that K179A, K180A, and K221A substitutions disrupt Core-SUMO-1 binding, while K220A substitution precludes Core-UBC9 binding. In vivo, Core mutant viruses (K179A, K180A, K220A, K221A) and (K220A, K221A) harboring those substitutions were attenuated in swine. These data shows a clear correlation between the disruption of Core protein binding to SUMO-1 and UBC9 and CSFV attenuation. Overall, these data suggest that the interaction of Core with the cellular SUMOylation pathway plays a significant role in the CSFV growth cycle in vivo.

Associations between exercise-induced pulmonary haemorrhage, right ventricular dimensions and atrioventricular valve regurgitation in conditioned National Hunt racehorses

REASONS FOR PERFORMING STUDY

Exercise-induced pulmonary haemorrhage (EIPH) and tricuspid (TR) and mitral valve regurgitation (MR) are conditions with high prevalence in conditioned Thoroughbreds. Stress failure of pulmonary capillaries, leading to EIPH, is most likely when pulmonary vascular pressure is increased, and mitral regurgitation can result in pulmonary venous hypertension.

HYPOTHESIS

There might be an association between MR and EIPH and the right ventricle (RV) of horses known to suffer repeated episodes of EIPH, as their hearts would be subject to higher pulmonary vascular pressures and cardiac output during training and hence increased RV afterload and preload.

METHODS

An echocardiographic and auscultation study was conducted in 121 race-fit National Hunt Thoroughbreds. Cardiac auscultation and echocardiography were performed. A guided M-mode image of the RV just below the tricuspid valve was obtained from a right parasternal location and colour flow Doppler (CFD) used to interrogate the tricuspid valve and right atrium. The mitral valve was similarly examined from the left hemithorax. Severity of TR and MR by CFD was graded. Binary data on EIPH, based on whether the horse was perceived to have a clinically significant problem with EIPH, were determined retrospectively for each horse by the horses' primary care veterinary surgeon from medical and other records. Data were analysed using a standard logistic regression analysis approach.

RESULTS

EIPH was significantly and positively associated with the systolic and diastolic dimensions of the RV (P = 0.017 and 0.011 respectively) and this association was not sensitive to the effects of age or weight. There were no significant associations between EIPH and TR or MR by auscultation or CFD (TR: auscultation P = 0.1; CFD P = 0.2 and MR: auscultation P = 0.07; CFD P = 0.37).

CONCLUSIONS AND CLINICAL RELEVANCE

This study was limited by the method used to classify EIPH, but there was no association between EIPH and horse age, weight, TR or MR in this population of Thoroughbreds. Nevertheless, RV internal dimension was greater in horses obviously affected by EIPH, suggesting that factors resulting in EIPH may directly or indirectly affect RV remodelling in athletic horses.

Measurements of right ventricular internal dimensions and their relationships to severity of tricuspid valve regurgitation in National Hunt Thoroughbreds

REASONS FOR PERFORMING STUDY

The effect of tricuspid valve regurgitation (TR) in right ventricular (RV) chamber size has not been reported.

METHODS

An echocardiographic and auscultation study was conducted on 394 race-fit National Hunt Thoroughbreds (TBs) in 4 training yards. Auscultation was performed on each horse and audible murmurs of TR graded using a 1-6 scale. Echocardiography was also performed and standard, 2-dimensional (2D), short (SA) and long axis (LA) images of the RV obtained from a right parasternal location. An m-mode image was recorded from an SA view of the RV just below the level of the tricuspid valve. Colour flow Doppler (CFD) echocardiography was used to interrogate the tricuspid valve and right atrium. If retrograde flow was visible, representative recordings were also acquired. Severity of TR by CFD was graded using a subjective 1-9 scale. Measurements of RV chamber size in systole and diastole were made from archived 2D, LA, SA and m-mode images by a single observer unaware of the auscultation and CFD findings. To determine day-to-day repeatability of RV measurements from each imaging plane and of TR by CFD, 5 horses were examined on 5 consecutive days using an identical echocardiographic protocol. Images from 30 horses in the original dataset were also measured on a second occasion to determine the intra-observer repeatability.

RESULTS

There were significant positive correlations between the severity of TR by CFD and RV internal diameter from each image plane. In contrast, there were no significant associations between grade of TR by auscultation and any RV dimension. Data also showed that only RV measurements derived from M-mode images have acceptable intraobserver repeatability and similarly the M-mode measurements had the best overall day-to-day repeatability.

CONCLUSIONS AND CLINICAL RELEVANCE

Data showed that TR assessed by CFD was positively associated with the diastolic and systolic dimensions of the RV, but failed to demonstrate a positive association between the presence of a murmur of TR and RV chamber size. M-mode and 2D echocardiography provided moderately reliable and repeatable methods for obtaining measurements of RV internal dimensions. M-mode images provide the most reliable and repeatable measurements, particularly for less experienced operators.

Risk factors for epistaxis on British racecourses: evidence for locomotory impact-induced trauma contributing to the aetiology of exercise-induced pulmonary haemorrhage

REASONS FOR PERFORMING STUDY

The proposed biological mechanisms for exercise-induced pulmonary haemorrhage (EIPH) are many and varied. Better knowledge of risk factors should lead to achievable measures to reduce the incidence.

OBJECTIVES

To identify risk factors associated with epistaxis following racing in UK Thoroughbreds, to gain possible insights into the pathogenesis of the condition and to investigate the association between epistaxis and race finishing position.

METHODS

The association of epistaxis occurring on UK racecourses between 1996 and 1998 with a wide range of race-, horse- and start-level variables was examined in multivariable mixed effect logistic regression analyses. Four multivariable analyses were conducted, one for all race types considered collectively and one each for flat, hurdle and steeplechase race types considered separately.

RESULTS

Risk of epistaxis was significantly increased for hurdle and steeplechase race types compared to both flat and National Hunt flat races. In 3 of the 4 final models, there was a significant biological trend for increasing risk of epistaxis with increasing ground hardness ('going') and accumulated years spent racing. However, in flat races epistaxis was such a rare outcome (0.33 cases per 1000 starts) that this subset analysis had insufficient power to measure the detectable effect of 'going' as statistically significant. Horses with epistaxis were significantly more likely to have a poorer finishing position than those without blood at the nostrils.

CONCLUSIONS

Findings were consistent with the theory that locomotory impact-induced trauma contributes to exercise-induced epistaxis. Further validation of this hypothesis through application of similar methods to endoscopically visible EIPH and through biomechanical studies is warranted.

POTENTIAL RELEVANCE

Knowledge of significant risk factors should allow formulation of practical measures, such as track watering, to reduce the risks of EIPH and epistaxis in racehorses.