Spatiotemporal image reconstruction to enable high-frame-rate dynamic photoacoustic tomography with rotating-gantry volumetric imagers

Significance

Dynamic photoacoustic computed tomography (PACT) is a valuable imaging technique for monitoring physiological processes. However, current dynamic PACT imaging techniques are often limited to two-dimensional spatial imaging. Although volumetric PACT imagers are commercially available, these systems typically employ a rotating measurement gantry in which the tomographic data are sequentially acquired as opposed to being acquired simultaneously at all views. Because the dynamic object varies during the data-acquisition process, the sequential data-acquisition process poses substantial challenges to image reconstruction associated with data incompleteness. The proposed image reconstruction method is highly significant in that it will address these challenges and enable volumetric dynamic PACT imaging with existing preclinical imagers.

Aim

The aim of this study is to develop a spatiotemporal image reconstruction (STIR) method for dynamic PACT that can be applied to commercially available volumetric PACT imagers that employ a sequential scanning strategy. The proposed reconstruction method aims to overcome the challenges caused by the limited number of tomographic measurements acquired per frame.

Approach

A low-rank matrix estimation-based STIR (LRME-STIR) method is proposed to enable dynamic volumetric PACT. The LRME-STIR method leverages the spatiotemporal redundancies in the dynamic object to accurately reconstruct a four-dimensional (4D) spatiotemporal image.

Results

The conducted numerical studies substantiate the LRME-STIR method's efficacy in reconstructing 4D dynamic images from tomographic measurements acquired with a rotating measurement gantry. The experimental study demonstrates the method's ability to faithfully recover the flow of a contrast agent with a frame rate of 10 frames per second, even when only a single tomographic measurement per frame is available.

Conclusions

The proposed LRME-STIR method offers a promising solution to the challenges faced by enabling 4D dynamic imaging using commercially available volumetric PACT imagers. By enabling accurate STIRs, this method has the potential to significantly advance preclinical research and facilitate the monitoring of critical physiological biomarkers.

In vivo noninvasive systemic myography of acute systemic vasoactivity in female pregnant mice

Altered vasoactivity is a major characteristic of cardiovascular and oncological diseases, and many therapies are therefore targeted to the vasculature. Therapeutics which are selective for the diseased vasculature are ideal, but whole-body selectivity of a therapeutic is challenging to assess in practice. Vessel myography is used to determine the functional mechanisms and evaluate pharmacological responses of vascularly-targeted therapeutics. However, myography can only be performed on ex vivo sections of individual arteries. We have developed methods for implementation of spherical-view photoacoustic tomography for non-invasive and in vivo myography. Using photoacoustic tomography, we demonstrate the measurement of acute vascular reactivity in the systemic vasculature and the placenta of female pregnant mice in response to two vasodilators. Photoacoustic tomography simultaneously captures the significant acute vasodilation of major arteries and detects selective vasoactivity of the maternal-fetal vasculature. Photoacoustic tomography has the potential to provide invaluable preclinical information on vascular response that cannot be obtained by other established methods.

Climate resilience and the human-water dynamics. The case of tomato production in Morocco

In Morocco, droughts are an increasing threat affecting water availability, agricultural production and producers' livelihoods. Moreover, water demand for irrigation has led to overexploitation of the groundwater table causing significant natural resource management challenges. The combination of groundwater changes and increasing drought risk raises concerns about the ability of agricultural producers to be resilient against drought. In this study, we describe the interactions of environmental and socioeconomic processes which influence farmers' livelihoods involved in tomato production in Morocco. Building on system dynamics modelling tools, we aim to improve the understanding of the long-term dynamic behavior of water management and to explore plausible policy scenarios necessary for sustainable and resilient water resource management and agricultural development. Our results show that tomato production is not yet severely impacted by droughts. However, droughts are accelerating the process of groundwater depletion, impacting farmers' livelihoods, by decreasing crop productivity and reducing farmer's revenue over a longer time period, especially since tomatoes are a high-value crop. Therefore, integrated and effective policies are presented as a set of measures for a systemic enhancement of resilience. We conclude that a more radical approach toward water resource conservation and upholding the most vulnerable producers has to be adopted in order to enhance a sustainable and inclusive resilience of the tomato production in Morocco.

Baseline brain function in the preadolescents of the ABCD Study

The Adolescent Brain Cognitive Development (ABCD) Study® is a 10-year longitudinal study of children recruited at ages 9 and 10. A battery of neuroimaging tasks are administered biennially to track neurodevelopment and identify individual differences in brain function. This study reports activation patterns from functional MRI (fMRI) tasks completed at baseline, which were designed to measure cognitive impulse control with a stop signal task (SST; N = 5,547), reward anticipation and receipt with a monetary incentive delay (MID) task (N = 6,657) and working memory and emotion reactivity with an emotional N-back (EN-back) task (N = 6,009). Further, we report the spatial reproducibility of activation patterns by assessing between-group vertex/voxelwise correlations of blood oxygen level-dependent (BOLD) activation. Analyses reveal robust brain activations that are consistent with the published literature, vary across fMRI tasks/contrasts and slightly correlate with individual behavioral performance on the tasks. These results establish the preadolescent brain function baseline, guide interpretation of cross-sectional analyses and will enable the investigation of longitudinal changes during adolescent development.

Indocyanine green dye based bimodal contrast agent tested by photoacoustic/fluorescence tomography setup

Multimodal imaging systems are in high demand for preclinical research, experimental medicine, and clinical practice. Combinations of photoacoustic technology with other modalities including fluorescence, ultrasound, MRI, OCT have been already applied in feasibility studies. Nevertheless, only the combination of photoacoustics with ultrasound in a single setup is commercially available now. A combination of photoacoustics and fluorescence is another compelling approach because those two modalities naturally complement each other. Here, we presented a bimodal contrast agent based on the indocyanine green dye (ICG) as a single signalling compound embedded in the biocompatible and biodegradable polymer shell. We demonstrate its remarkable characteristics by imaging using a commercial photoacoustic/fluorescence tomography system (TriTom, PhotoSound Technologies). It was shown that photoacoustic signal of the particles depends on the amount of dye loaded into the shell, while fluorescence signal depends on the total amount of dye per particle. For the first time to our knowledge, a commercial bimodal photoacoustic/fluorescence setup was used for characterization of ICG doped polymer particles. Additionally, we conducted cell toxicity studies for these particles as well as studied biodistribution over time in vivo and ex vivo using fluorescent imaging. The obtained results suggest a potential for the application of biocompatible and biodegradable bimodal contrast agents as well as the integrated photoacoustic/fluorescence imaging system for preclinical and clinical studies.

1170 Trends in Sleep Apnea Testing Among Veterans Participating in a Rural Health-Focused Telesleep Medicine Program

Introduction

The Department of Veterans Affairs has pioneered the use of home sleep apnea testing (HSAT) across many of its medical centers over the past 15 years. Here we report trends regarding diagnostic sleep apnea testing in rural and urban Veterans served by the TeleSleep Program, a VA telehealth initiative focused on increasing access to sleep care for rural Veterans. Rurality is a risk factor for use of polysomnography and is associated with longer wait times for testing and initiation of PAP therapy.

Methods

We used a VA administrative database search of patients enrolled in sleep medicine clinics from fiscal years (FY) 2016-2019 at 7 TeleSleep Hubs: San Francisco, Portland, Phoenix, Boise, Philadelphia, Spokane, and Pittsburgh. Individual encounters were coded locally and transmitted to VA’s corporate data warehouse. HSAT codes included 95800, 95801, 95806, G0398, G0399, and G0400. Polysomnography codes included 95807, 95808, 95810, and 95811.

Results

Total number of unique Veterans served increased between FY16 and FY19 from 28,941 to 43,044 (149%); rural Veterans served during this time increased from 9,386 to 14,329 (153%). The total number of annual sleep medicine encounters for all Veterans served increased from 89,870 to 138,127 (154%); rural Veteran visits increased from 29,825 to 50,342 (169%). Unique urban Veterans tested by HSAT increased from 2,158 in FY16 to 4,398 in FY19 (203%) while polysomnography decreased from 5,011 to 3,253 (35%). Unique rural Veterans tested by HSAT increased from 1,102 to 2,768 (251%) and polysomnography decreased by 42% (1,565 to 909 Veterans) during this same time.

Conclusion

Among VA sleep medicine programs with TeleSleep funding, HSAT became the most common approach to diagnostic sleep apnea testing, particularly in rural Veterans. Although polysomnography was widely used at the beginning of the TeleSleep Initiative, use declined as HSAT became more widely implemented.

Support

VA Office of Rural Health

Factors associated with antibiotic prescribing for adults with acute conditions: an umbrella review across primary care and a systematic review focusing on primary dental care

INTRODUCTION

One way to slow the spread of resistant bacteria is by improved stewardship of antibiotics: using them more carefully and reducing the number of prescriptions. With an estimated 7%-10% of antibiotic prescriptions globally originating from dental practices and up to 80% prescribed unnecessarily, dentistry has an important role to play. To support the design of new stewardship interventions through knowledge transfer between contexts, this study aimed to identify factors associated with the decision to prescribe antibiotics to adults presenting with acute conditions across primary care (including dentistry).

METHODS

Two reviews were undertaken: an umbrella review across primary healthcare and a systematic review in dentistry. Two authors independently selected and quality assessed the included studies. Factors were identified using an inductive thematic approach and mapped to the Theoretical Domains Framework (TDF). Comparisons between dental and other settings were explored. Registration number: PROSPERO_CRD42016037174.

RESULTS

Searches identified 689 publications across primary care and 432 across dental care. Included studies (nine and seven, respectively) were assessed as of variable quality. They covered 46 countries, of which 12 were low and middle-income countries (LMICs). Across the two reviews, 30 factors were identified, with 'patient/condition characteristics', 'patient influence' and 'guidelines & information' the most frequent. Two factors were unique to dental studies: 'procedure possible' and 'treatment skills'. No factor related only to LMICs.

CONCLUSIONS

A comprehensive list of factors associated with antibiotic prescribing to adults with acute conditions in primary care settings around the world has been collated and should assist theory-informed design of new context-specific stewardship interventions.

Modelling of focused ion beam induced increases in sample temperature: a case study of heat damage in biological samples

Ion beam induced heat damage in soft materials and biological samples is not yet well understood in Focused Ion Beam systems (FIBs). The work presented here discusses the physics behind the ion beam - sample interactions and the effects which lead to increases in sample temperature and potential heat damage. A model by which heat damage can be estimated and which allows parameters to be determined that reduce/prevent heat damage was derived from Fourier's law of heat transfer and compared to finite element simulations, numerical modelling results and experiments. The results suggests that ion beam induced heat damage can be prevented/minimised by reducing the ion beam current (local dose rate), decreasing the beam overlap (reduced local ion dose) and by introducing a blur (increased surface cross-section area, reduced local dose) while sputtering, patterning or imaging soft material and nonresin-embedded biological samples using FIBs.

LAY DESCRIPTION

FIB/SEMs, which combine a scanning electron microscope with a focused ion beam in a single device, have found increasing interest biological research. The device allows to cut samples at precisely selected areas and reveal sub surface information as well as preparing transmission electron microscope samples from bulk materials. Preparing biological samples has proven to be challenging due to the induced heat damage. This work explores the physics behind the sample cutting and proposes a model and a method, based on physical principles which allows the user to estimate the induced heat during the cutting process and to select cutting parameters which avoid heat damage in the sample.

Recruiting the ABCD sample: Design considerations and procedures

The ABCD study is a new and ongoing project of very substantial size and scale involving 21 data acquisition sites. It aims to recruit 11,500 children and follow them for ten years with extensive assessments at multiple timepoints. To deliver on its potential to adequately describe adolescent development, it is essential that it adopt recruitment procedures that are efficient and effective and will yield a sample that reflects the nation’s diversity in an epidemiologically informed manner. Here, we describe the sampling plans and recruitment procedures of this study. Participants are largely recruited through the school systems with school selection informed by gender, race and ethnicity, socioeconomic status, and urbanicity. Procedures for school selection designed to mitigate selection biases, dynamic monitoring of the accumulating sample to correct deviations from recruitment targets, and a description of the recruitment procedures designed to foster a collaborative attitude between the researchers, the schools and the local communities, are provided.

Analysis of cervical sagittal alignment variations after lumbar pedicle subtraction osteotomy for severe imbalance: study of 59 cases

OBJECTIVE

To evaluate postoperative changes within the cervical alignment following surgical lumbar correction by pedicle subtraction osteotomy (PSO) in patients affected with sagittal global malalignment disease.

METHODS

This was a monocentric, radiographic, and prospective study. 79 patients, who underwent sagittal correction by PSO, performed an EOS imaging pre- and postoperatively between January 2008 and December 2013 at the University Hospital of Bordeaux. Inclusion criteria were a performed pre- and postoperative EOS imaging and a preoperative C7SVA > 5 cm. Were excluded patients who did not allow EOS with a viewable cervical spine due to hyperkyphosis. The study involved the analysis of pelvic, lumbar, thoracic, cervical, and cranial parameters before and after the surgery.

RESULTS

59 patients met the criteria. Mean follow-up was 38 months. The lumbar PSO significantly improved sagittal alignment including L1S1 lordosis, T1T12 kyphosis, and C7SVA (p < 0.001). We did not reported a significant change within cervical parameters after PSO (C2C7 lordosis 22.7°-21.5° p = 0.64, C1C7 lordosis 50.6°-48.8° p = 0.56, C1C2 angle 28.2°-27.9° p = 0.82, C7 slope stayed constant 32.3°-30.5° p = 0.47, OC2 angle 15.54°-15.56° p = 0.99). However, cranial slope decreased significantly (p < 0.05). We did not find correlation between lumbar lordosis and cervical lordosis variations (R = 0.265). Cervical lordosis was highly correlated with the C7 slope (R = 0.597) and with the Spino Cranial Angle (R = - 0.867).

CONCLUSION

Reciprocal changes in cervical spine after PSO are difficult to approach. Maintaining a horizontal gaze involves locoregional mechanisms of compensation adapting to the slope of C7. The cranial system by decreasing the cranial slope allows the gaze alignment and is the first compensation mechanism to get involved after a loss of lumbar lordosis. Restoring optimal C7SVA is necessary to prevent the development of secondary cervical painful symptomatology when the cranial compensation is outdated.

At-a-glance, Emergency department surveillance of thermal burns and scalds, electronic Canadian Hospitals Injury Reporting and Prevention Program, 2013

INTRODUCTION

Although fatality and hospitalization rates for burns in Canada have declined over time, less serious cases still commonly present to the emergency department (ED).

METHODS

The Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) is an injury and poisoning surveillance system administered by the Public Health Agency of Canada, operating in emergency departments of 17 hospitals.

RESULTS

Overall, cases reported in 2013 were scalds and contact burns from hot objects. The leading direct causes of scalds were hot beverages and hot water. The leading causes of contact burns were stoves/ovens and fireplaces/accessories. While the overall proportion of burns was highest among females, males comprised a higher proportion of burns from all mechanisms except scalds.

Suicide and self-inflicted injury hospitalizations in Canada (1979 to 2014/15)

INTRODUCTION

The purpose of this paper is to describe the trends and patterns of self-inflicted injuries, available from Canadian administrative data between 1979 and 2014/15, in order to inform and improve suicide prevention efforts.

METHODS

Suicide mortality and hospital separation data were retrieved from the Public Health Agency of Canada (PHAC) holdings of Statistics Canada's Canadian Vital Statistics: Death Database (CVS:D) (1979 to 2012); Canadian Socio-Economic Information Management System (CANSIM 2011, 2012); the Hospital Morbidity Database (HMDB) (1994/95 to 2010/11); and the Discharge Abstract Database (2011/12 to 2014/15). Mortality and hospitalization counts and rates were reported by sex, 5-year age groups and method.

RESULTS

The Canadian suicide rate (males and females combined, all ages, age-sex standardized rate) has decreased from 14.4/100 000 (n = 3355) in 1979 to 10.4/100 000 (n = 3926) in 2012, with an annual percent change (APC) of -1.2% (95% CI: -1.3 to -1.0). However, this trend was not observed in both sexes: female suicide rates stabilized around 1990, while male rates continued declining over time-yet males still accounted for 75.7% of all suicides in 2012. Suffocation (hanging and strangulation) was the primary method of suicide (46.9%) among Canadians of all ages in 2012, followed by poisoning at 23.3%. In the 2014/15 fiscal year, there were 13 438 hospitalizations in Canada (excluding Quebec) associated with self-inflicted injuries-over 3 times the number of suicides. Over time females have displayed consistently higher rates of hospitalization for self-inflicted injury than males, with 63% of the total. Poisoning was reported as the most frequent means of self-inflicted harm in the fiscal year 2014/15, at 86% of all hospitalizations.

CONCLUSION

Suicides and self-inflicted injuries continue to be a serious - but preventable - public health problem that requires ongoing surveillance.

Abstract PD5-01: Microenvironment microarrays show that microenvironment mediated resistance mechanisms to lapatinib differ between basal and luminal HER2+ cells

Cell lines represent a valuable model system for the study of breast cancer, as they capture the cellular diversity, mutational spectrum, expression subtypes, and genomic alterations that are observed in clinical specimens. However, like any model system, cell lines are imperfect, particularly when it comes to capturing the effects of the myriad of signals and interactions they encounter in their microenvironment (ME). We are utilizing a technology known as microenvironment microarrays (MEMA) to begin to unravel the consequences of interactions of breast cancer cells with the ME. MEMA consist of thousands of unique combinations of insoluble matrix proteins that are printed to form growth pads with ligands added to the media. Cells are grown on the MEMA spots and the effects of the specific ME that they are exposed to can be read out using immunofluorescent stains of interest. When combined with automated imaging and sophisticated image processing and analysis, the MEMA platform enables the identification of specific ME conditions that alter the phenotypes of cells. We have applied MEMA to understand both baseline responses to the ME as well as how the ME might mediate response to therapeutics. We performed a pilot experiment to investigate the effects of the ME on the response to the HER2-targeted inhibitor lapatinib. We found that HCC1954 cells continued to proliferate robustly in the presence of HGF when treated with 500 nM lapatinib. In contrast, AU565 cells were proliferative in the presence of NRG1 and lapatinib, but not HGF. Focused follow up studies showed that HGF is effective in rescuing only basal HER2+ cells, while NRG1 is effective in rescuing only luminal subtype HER2+cells. Rescue with the relevant growth factor was also observed in 3-d matrigel studies, showing this was not an artifact of the 2-d culture system. We investigated the effects of drug combinations using lapatinib plus drugs that target either MET (Crizotinib) or HER3-HER2 dimers (pertuzumab). These drug combinations were able to overcome the resistance mediated by HGF and NRG1 in basal and luminal cells respectively. We found the effectiveness of pertuzumab particularly interesting, given that lapatinib should still be inhibiting HER2 kinase activity. Parallel studies found that inhibitors targeting other kinase receptors such as IGF1R partially restored sensitivity to HER2 in the presence of NRG1, suggesting a role for such receptors in the resistance. Immunoprecipitation studies showed that IGF1R co-immunoprecipitated with HER2/HER3 when pertuzumab was absent, but that additional of pertuzumab abrogated the binding of IGF1R to HER3, suggesting the formation of HER2-dependent higher order structures that can signal even when HER2 is inhibited. These studies highlight the importance of understanding the effects of the ME on cancer cells, and demonstrate the differences between ME factors that can confer resistance to HER2 targeted inhibitors in basal and luminal HER2+ cells. These findings suggest that both subtype and ME composition may be important in determining response to combinatorial treatments and may be useful to inform clinical decision making.

Citation Format: Korkola JE, Watson S, Smith R, Thompson W, Dame M, Liby T, Bucher E, Sudar D, Nederlof M, Heiser L, Gray JW. Microenvironment microarrays show that microenvironment mediated resistance mechanisms to lapatinib differ between basal and luminal HER2+ cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD5-01.

The use of magnetically-controlled growing rods to treat children with early-onset scoliosis: early radiological results in 19 children

AIMS

We undertook a prospective non-randomised radiological study to evaluate the preliminary results of using magnetically-controlled growing rods (MAGEC System, Ellipse technology) to treat children with early-onset scoliosis.

PATIENTS AND METHODS

Between January 2011 and January 2015, 19 children were treated with magnetically-controlled growing rods (MCGRs) and underwent distraction at three-monthly intervals. The mean age of our cohort was 9.1 years (4 to 14) and the mean follow-up 22.4 months (5.1 to 35.2). Of the 19 children, eight underwent conversion from traditional growing rods. Whole spine radiographs were carried out pre- and post-operatively: image intensification was used during each lengthening in the outpatient department. The measurements evaluated were Cobb angle, thoracic kyphosis, proximal junctional kyphosis and spinal growth from T1 to S1.

RESULTS

The mean pre-, post-operative and latest follow-up Cobb angles were 62° (37.4 to 95.8), 45.1° (16.6 to 96.2) and 43.2° (11.9 to 90.5), respectively (p < 0.05). The mean pre-, post-operative and latest follow-up T1-S1 lengths were 288.1 mm (223.2 to 351.7), 298.8 mm (251 to 355.7) and 331.1 mm (275 to 391.9), respectively (p < 0.05). In all, three patients developed proximal pull-out of their fixation and required revision surgery: there were no subsequent complications. There were no complications of outpatient distraction.

CONCLUSIONS

Our study shows that MCGRs provide stable correction of the deformity in early-onset scoliosis in both primary and revision procedures. They have the potential to reduce the need for multiple operations and thereby minimise the potential complications associated with traditional growing rod systems. Cite this article: Bone Joint J 2016;98-B:1240-47.

Impulse responses of visible phototubes used in National Ignition Facility neutron time of flight diagnostics

Neutron-induced visible scintillation in neutron time of flight (NToF) diagnostics at the National Ignition Facility (NIF) is measured with 40 mm single stage micro-channel plate photomultipliers and a 40 mm vacuum photodiode, outside the neutron line of sight. In NIF experiments with 14 MeV neutron yields above Y > 10 × 10¹⁵ these tubes are configured to deliver of order 1 nC of charge in the nominally 5 ns NToF into a 50 Ω load. We have examined a number of 40 mm tubes manufactured by Photek Ltd. of St. Leonards on Sea, UK, to determine possible changes in the instrument impulse response as a function of signal charge delivered in 1 ns. Precision NToF measurements at approximately 20 m require that we characterize changes in the impulse response moments to <40 ps for the first central moment and ∼2% rms for the square root of the second central moment with ∼500 ps value. Detailed results are presented for three different diode configurations.

Effects of hair sprays on colour perception: a hyperspectral imaging approach to shine and chroma on heads

OBJECTIVES

Hair sprays apply fixative ingredients to provide hold to a hair style as well as weather resistance and optical properties such as shine. Generally, sprays distribute fine particles containing polymeric ingredients to form a thin film on the surface of hair. Different hair types require different strengths of the formed deposit on the hair surface. The present study shows how sprays also alter the visibility of the hair colour by altering the surface topology of the hair fibres.

METHODS

Hyperspectral imaging is used to map spectral characteristics of hair on mannequins and panelists over the curvature of heads. Spectral and spatial characteristics are measured before and after hair spray applications. The hair surface is imaged by SEM to visualize the degree of cuticle coverage. Finally, the perception of hair colour was evaluated on red-coloured mannequins by consumer questionnaire.

RESULTS

Hair sprays deposit different degrees of fixatives, which lead to a progressive leveling of the cuticle natural tilt angle with respect to the fibre axis. As a result, shine is progressively shifting towards the region of hair colour visibility and decreases the perceived colour of hair seen by consumers. Lighter sprays show thinner film formation on the hair surface and less of a shine shift than strong hold hair sprays.

CONCLUSIONS

Hair sprays are generally employed for hair style hold and weather resistance and considered without effect on hair colour. Our approach shows that spray-deposited films can affect colour perception by altering the microstructure of the hair surface. Thin films deposited on the hair fibre surface can partially fill gaps between cuticles, which reduces the cuticle natural angle. This partial erasure results in a angle shift of the shine regions towards the angle of internal reflection, thus decreasing the perceived hair colour regions as experienced by a group of consumers.

Fall-related injuries among Canadian seniors, 2005-2013: an analysis of the Canadian Community Health Survey

INTRODUCTION

We describe the epidemiology and trends of fall-related injuries among Canadian seniors aged 65 years and older by sex and age, as well as the circumstances and consequences of their injuries.

METHODS

We analyzed nationally representative data from the 2005, 2009/2010 and 2013 samples of the Canadian Community Health Survey to calculate the number and rates of fall-related injuries for each survey year. Where possible, we combined data from two or more samples to estimate the proportion of fall-related injuries by type of injury, part of body injured, type of activity and type of treatment.

RESULTS

The rate of fall-related injuries among seniors increased from 49.4 to 58.8 per 1000 population between 2005 and 2013, during which the number of fall-related injuries increased by 54% overall. Women had consistently higher rates than men across all survey years, while rates increased with advancing age. The upward trend in fall-related injury rates was more prominent among women and younger age groups. The most common type of injury was broken or fractured bones (37%), and the shoulder or upper arm (16%) was the most commonly injured body part. Many fall-related injuries occurred while walking on a surface other than snow or ice (45%). Over 70% of seniors seeking treatment for their injuries visited a hospital emergency department.

CONCLUSION

Given the increase in both the number and rates of fall-related injuries over time, there is a need to continue monitoring trends and injury patterns associated with falls.

Status report - The Canadian Hospitals Injury Reporting and Prevention Program: a dynamic and innovative injury surveillance system

This status report on the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), an emergency department-based injury and poisoning surveillance system, describes the result of migrating from a centralized data entry and coding process to a decentralized process, the web-based eCHIRPP system, in 2011. This secure system is improving the CHIRPP's overall flexibility and timeliness, which are key attributes of an effective surveillance system. The integrated eCHIRPP platform enables near real-time data entry and access, has user-friendly data management and analysis tools, and allows for easier communication and connectivity across the CHIRPP network through an online collaboration centre. Current pilot testing of automated data monitoring and trend analysis tools-designed to monitor and flag incoming data according to predefined criteria (for example, a new consumer product)-is revealing eCHIRPP's potential for providing early warnings of new hazards, issues and trends.

Escorts' knowledge of their duty of care to patients who have undergone intravenous sedation

AIM

To assess escorts' understanding of their responsibilities to the patient 24 hours following dental treatment under intravenous sedation.

STANDARDS

One hundred per cent of escorts: have been informed of their duties, have read the information sheet, expect at least a one hour appointment, identify the hazardous activities patients should avoid following sedation, travel by private transport, are aware that medications are taken as normal, should have care in place 24 hours following sedation.

METHOD

This was a prospective questionnaire-based audit. Questionnaires were handed to escorts of patients receiving treatment under intravenous sedation in Newcastle Dental Hospital sedation department.

RESULTS

Of 104 responses, 91.3% of escorts were informed about their duties and 79.8% had read the information sheet prior to the appointment. Boiling a kettle and Internet use were the most selected hazardous activities that escorts deemed safe for patients to carry out postoperatively (19.2%, 23.0%.) Private transport home was mainly used (car 73.1%, taxi 24.9%.) Following sedation, 93.3% of patients had an escort for 24 hours.

CONCLUSION

Escorts' basic knowledge fell short of the standard. Improvements are needed to ensure patient safety.

RECOMMENDATIONS

At the pre-assessment, the patient might be given an information sheet solely for the escort and encouraged to explain this to the escort. More comprehensive information listing activities hazardous to the patient 24 hours following sedation and emphasising that taking medications as normal preoperatively could be available on the treatment day. Transport information in the appointment letter might improve access. A Trust website link, a DVD and posters in the waiting room could further inform.

Report summary - Injury in Review, 2012 Edition: Spotlight on Road and Transport Safety

Injury in Review, 2012 Edition: Spotlight on Road and Transport Safety, the first national public health report of its kind, synthesizes road- and transport-related injury statistics from a variety of sources. It profiles injury patterns among Canadians aged up to 24 years, explains risks and protective factors, and makes recommendations for action. The findings inform the development of targeted injury prevention efforts.

Report summary - injury in review, 2012 edition: spotlight on road and transport safety

Injury in Review, 2012 Edition: Spotlight on Road and Transport Safety, the first national public health report of its kind, synthesizes road- and transport-related injury statistics from a variety of sources. It profiles injury patterns among Canadians aged up to 24 years, explains risks and protective factors, and makes recommendations for action. The findings inform the development of targeted injury prevention efforts.

Assisted reproductive technology treatment outcomes

Information on the outcomes of ART treatments in Ireland is not readily available to Irish practitioners. The data for hospital affiliated clinics has been made available for many years and is included in the hospital reports. We present a 10-year analysis of the Irish ART results voluntarily reported by six out of seven IVF clinics. The data was collected from published ESHRE reports and from results (2007-8) not yet published. Data collected included: number of clinics and ART cycles, female age, clinical and multiple pregnancy rates and treatment complications. The clinical pregnancy rate per embryo transfer was 31.7% for IVF and 29.8% for ICSI. The proportion of singleton, twin and triplet deliveries for IVF and ICSI combined was 75%, 23.35% and 1.64%. The rate of ovarian hyperstimulation was 0.8%. ART practice in Ireland is safe, effective and responsible. Financial and societal savings could result from the introduction of state funded IVF with compulsory eSET where recommended.

Multiresidue mycotoxin analysis in wheat, barley, oats, rye and maize grain by high-performance liquid chromatography-tandem mass spectrometry

A method has been developed for the simultaneous analysis of 22 mycotoxins in wheat, barley, oats, rye and maize grain. Analysis is carried out with liquid chromatography-electrospray ionisation tandem mass spectrometry. The compounds included in this analysis are aflatoxins, sterigmatocystin, cyclopiazonic acid, tricothecenes, ochratoxin A, fumonisins, zearalonone, and ergot alkaloids. Sample extraction (2 g) with acetonitrile:water (8 ml, 80:20) was carried out for 2 min using a commercial sample preparation apparatus (Stomacher®). The extract was then centrifuged, filtered and analysed. Extraction of fumonisins from maize (2 g) was optimised by first extracting the maize with acetonitrile: water (5 ml, 80:20) followed by the addition of water (3 ml), which permitted extraction of the 22 mycotoxins, including the fumonisins. Chromatography was carried out with a minicolumn (7.5×2.1 mm, 5 µm) (5 µl sample injection) and in 11 min, including column reconditioning. Analysis was carried out with 2 MRM transitions for the precursor ions. All method detection limits were below current maximum Canadian residue limits. Matrix effects for each compound in each of the 5 matrices were estimated and ranged from 70 to 149%, but most were 100±10%. Accuracy, repeatability and ruggedness were established. Proficiency samples from FERA (Food and Environment Research Agency, Sand Hutton, York, UK) were tested and are reported. Finally, 100 field samples of the various grains were tested with this method and are reported with the observation of numerous mycotoxins in all matrices, including ergotamine in winter wheat.

Stability of cyclopiazonic acid in solution

Cyclopiazonic acid (CPA) is an important mycotoxin given its toxicity and prevalence in foods and feeds. There is tremendous interest in developing analytical methods that include CPA as part of a multi-residue mycotoxin routine, but there appears to be considerable difficulty in analysing it using liquid chromatography with electrospray ionisation tandem mass spectrometry (LC-MS/MS). During the development of a multi-residue method for mycotoxins including CPA, a number of issues were discovered under routine and common analytical conditions that have an impact on the determination of CPA, including: (1) at the ng/ml level CPA reacts with ambient oxygen from the headspace of the vial, an effect that decreases its concentration linearly; (2) CPA readily adsorbs to plastic in a reversible fashion; (3) CPA is acid hydrolysed with formic acid; (4) CPA reacts with the column stationary phase affecting chromatographic parameters; and (5) CPA presents significant carry-over issues. In an effort to find solutions to these problems we found that CPA can be protected from reacting with oxygen by adding 1 µg/ml ascorbic acid and that its carry-over can be reduced to a negligible level by injecting ammonia between injections of solutions containing CPA, even with formic acid in the mobile phase. Chromatographic conditions for CPA have been optimised in consideration of all of the aforementioned concerns.

Excision of pre-ulcerative forms of Buruli ulcer disease: a curative treatment?

BACKGROUND

Previous investigations have revealed that Mycobacterium ulcerans is extensively distributed spatially throughout ulcerative lesions, including in the margins of excised tissue. In contrast, bacilli in pre-ulcerative lesions are assumed to be concentrated in the center of the lesion. In order to assess the extent to which the surgical excision of pre-ulcerative lesions is capable of removing all infected tissue, we subjected the excision margins of pre-ulcerative lesions to laboratory analysis.

PATIENTS AND METHODS

Eleven patients with laboratory-confirmed pre-ulcerative lesions were included in the study. The diameter of the lesion and excised tissue and the "surgical distance" between the border of the lesion and excision margin were measured. The entire excision margin was cut into segments and subjected to IS2404 PCR.

RESULTS

The results from the PCR analysis on the samples of excision margins were highly significantly associated with the surgical distance (p < 0.001). The margin samples of nodules were significantly more often PCR positive than the plaques (p = 0.025). The size of the lesion and the size of the excised tissue did not significantly influence the PCR results. Statistically, a surgical distance of more than 9 mm was found to reduce the risk of remaining infected tissue to less than 10%, that of 13 mm to reduce the risk to less than 5%, and that of 25 mm to reduce the risk to nearly 0%.

CONCLUSION

The results of this study show that in preulcerative Buruli ulcer disease, bacilli may extend beyond the actual size of the lesion and that there is a strong correlation between the presence of M. ulcerans in the margin samples and the surgical distance. Excision with a surgical distance of 25 mm avoided the risk of remaining mycobacteria in this study. However, no recurrences occurred in the patients with M. ulcerans-positive excision margins. The need of postoperative antimycobacterial treatment in these patients remains to be determined.

The effect of the hypohydration on the lactate threshold in a hot and humid environment

AIM

The purpose of this study was to investigate the effect of hypohydration (HH) on the lactate threshold (LT) in a hot and humid environment.

METHODS

Ten apparently healthy males (age 25+/-3 yrs; height 1.8+/-0.04 m; mass 78+/-12 kg; VO2peak 3.7+/-0.4 L/min) underwent four randomly assigned maximal treadmill tests. Two trials were at room temperature (22+/-1 degrees C; RH = 50%) under two different hydration conditions: euhydrated (EH-RM) and hypohydrated (HH-RM), and two trials were performed in a warm chamber (37+/-0.5 degrees C; RH = 70%) under two different hydration conditions: euhydrated (EH-HT) and hypohydrated (HH-HT). The desired HH level (2-4%) was accomplished in the 24+ hours before testing by fluid restriction. Mean HH was 2.6+/-1.0% body weight. Capillary blood samples were collected at the end of each stage and analyzed for lactic acid (LA). LA concentrations were plotted for each exercise stage, and the LT was determined by visual inspection as the highest exercise stage at which blood LA concentration began to increase above each individual's resting levels. LT and body temperature were analyzed with a two-way repeated measures ANOVA (P < 0.05).

RESULTS

During the trials in the warm chamber, the LT occurred at a significantly earlier stage compared to the thermoneutral environment (4.4+/-0.09 vs 5.8+/-0.10) and with a significantly lower oxygen consumption (2.38+/-0.09 L.min(-1) vs 2.86+/-0.13 L.min(-1)). Body temperature at the LT was significantly higher in the heat trials compared to room temperature (38.7+/-0.12 degrees C vs 37.6+/-0.14 degrees C). LT determination was not significantly altered by hydration.

CONCLUSION

These results suggest that during progressive incremental maximal treadmill exercise, moderate HH does not affect the LT, whereas exercise in a hot and humid environment induces a downward shift in the LT. The elevated body temperature during the heat trials suggests that body temperature may affect running performance associated with the LT.