Computed tomographic angiography measures of coronary plaque in clinical trials: opportunities and considerations to accelerate drug translation

Atherosclerotic coronary artery disease (CAD) is the causal pathological process driving most major adverse cardiovascular events (MACE) worldwide. The complex development of atherosclerosis manifests as intimal plaque which occurs in the presence or absence of traditional risk factors. There are numerous effective medications for modifying CAD but new pharmacologic therapies require increasingly large and expensive cardiovascular outcome trials to assess their potential impact on MACE and to obtain regulatory approval. For many disease areas, nearly a half of drugs are approved by the U.S. Food & Drug Administration based on beneficial effects on surrogate endpoints. For cardiovascular disease, only low-density lipoprotein cholesterol and blood pressure are approved as surrogates for cardiovascular disease. Valid surrogates of CAD are urgently needed to facilitate robust evaluation of novel, beneficial treatments and inspire investment. Fortunately, advances in non-invasive imaging offer new opportunity for accelerating CAD drug development. Coronary computed tomography angiography (CCTA) is the most advanced candidate, with the ability to measure accurately and reproducibly characterize the underlying causal disease itself. Indeed, favourable changes in plaque burden have been shown to be associated with improved outcomes, and CCTA may have a unique role as an effective surrogate endpoint for therapies that are designed to improve CAD outcomes. CCTA also has the potential to de-risk clinical endpoint-based trials both financially and by enrichment of participants at higher likelihood of MACE. Furthermore, total non-calcified, and high-risk plaque volume, and their change over time, provide a causally linked measure of coronary artery disease which is inextricably linked to MACE, and represents a robust surrogate imaging biomarker with potential to be endorsed by regulatory authorities. Global consensus on specific imaging endpoints and protocols for optimal clinical trial design is essential as we work towards a rigorous, sustainable and staged pathway for new CAD therapies.

Anatomic and functional discordance among patients with non-obstructive coronary disease

Background

Non-obstructive coronary artery disease (CAD) is associated with increased adverse cardiovascular (CV) events. However, it is unclear if functional stenosis, as assessed by FFRCT <0.80, further stratifies risk among patients with non-obstructive CAD and which factors contribute to this anatomic-functional discordance (stenosis <50% and FFRCT <0.80).

Purpose

We hypothesized that patients with anatomically non-obstructive CAD by CTA and an abnormal FFRCT value of ≤0.80 have a phenomenon termed anatomic-functional discordance, and this discordance would be associated with increased adverse outcomes.

Methods

Patients in the ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care) Registry who had exclusively non-obstructive CAD (anatomic stenosis <50%) were stratified by FFRCT >0.80 in all coronary vessels (concordant) vs. FFRCT <0.80 in at least one vessel (discordant). Baseline patient demographics, coronary computed tomography angiography findings, downstream testing and clinical outcomes were compared between groups. The primary composite endpoint included revascularization, CV hospitalization, heart failure, arrhythmia, non-fatal myocardial infarction, unplanned hospitalization for an acute coronary syndrome leading to urgent revascularization, and all-cause death.

Results

Among 1,261 patients with non-obstructive CAD, 543 (43.1%) had functional stenosis with FFRCT <0.80. Patients in the discordant group were older, more likely to have hypertension, hyperlipidemia, and had significantly higher indexed left ventricular (LV) mass and significantly lower coronary volume-to-mass ratios when compared with patients in the concordant group. Downstream non-invasive testing was more common among patients with discordance (35.9% vs 20.2%, p<0.0001) and more frequently resulted in a positive downstream test (10.3% vs. 3.3%, p<0.0001). Invasive angiography was also more common among patients with discordance (25.2% vs. 11.6%, p<0.0001). Anatomic-functional discordance was associated with higher rates of CV hospitalization and percutaneous coronary intervention (both p<0.0001), but no significant difference in all-cause death. After adjustment, anatomic-functional discordance was associated with a significantly higher risk of the composite endpoint (adjusted HR 2.79, 95% CI 1.67–4.65), Figure 1. As shown in Figure 2, the more vessels with anatomic-functional discordance, the higher the rate of adverse cardiac events.

Conclusion

Anatomic-functional discordance was present in nearly half of patients with exclusively non-obstructive CAD. The lower coronary volume: LV mass ratio may reflect abnormal coronary physiology at lower thresholds of anatomical stenosis among those with discordance. Compared to patients with concordance, patients with discordance had worse clinical outcomes suggesting that anatomic-functional discordance may stratify risk for adverse CV events among patients with non-obstructive CAD.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): The analysis was an investigator-initiated analysis sponsored by Heart Flow.

Invasive mammary carcinoma in a black-handed spider monkey (Ateles geoffroyi)

Mammary neoplasia is rare in nonhuman primates other than macaques; records in New World primates are exceedingly rare. We report the pathologic and immunohistochemical features of an invasive carcinoma no special type with neuroendocrine differentiation in a captive, black-handed spider monkey (Ateles geoffroyi).

Fractional flow reserve derived from computed tomography coronary angiography in the assessment and management of stable chest pain: the FORECAST randomized trial

Aims 

Fractional flow reserve (FFR_CT) using computed tomography coronary angiography (CTCA) determines both the presence of coronary artery disease and vessel-specific ischaemia. We tested whether an evaluation strategy based on FFR_CT would improve economic and clinical outcomes compared with standard care.

Methods and results 

Overall, 1400 patients with stable chest pain in 11 centres were randomized to initial testing with CTCA with selective FFR_CT (experimental group) or standard clinical care pathways (standard group). The primary endpoint was total cardiac costs at 9 months. Secondary endpoints were angina status, quality of life, major adverse cardiac and cerebrovascular events, and use of invasive coronary angiography. Randomized groups were similar at baseline. Most patients had an initial CTCA: 439 (63%) in the standard group vs. 674 (96%) in the experimental group, 254 of whom (38%) underwent FFR_CT. Mean total cardiac costs were higher by £114 (+8%) in the experimental group, with a 95% confidence interval from −£112 (−8%) to +£337 (+23%), though the difference was not significant (P = 0.10). Major adverse cardiac and cerebrovascular events did not differ significantly (10.2% in the experimental group vs. 10.6% in the standard group) and angina and quality of life improved to a similar degree over follow-up in both randomized groups. Invasive angiography was reduced significantly in the experimental group (19% vs. 25%, P = 0.01).

Conclusion 

A strategy of CTCA with selective FFR_CT in patients with stable angina did not differ significantly from standard clinical care pathways in cost or clinical outcomes, but did reduce the use of invasive coronary angiography.

Pre-migration TB screening-the first step is always the hardest

As the proportion of foreign-born persons among TB notifications continues to rise, Japan is preparing to introduce pre-migration TB screening for those coming from selected countries, who are intending to stay for more than 90 days. It has announced that the programme will commence in 2020. In this review, the authors examine the experiences from two countries which already have years of experience in operating pre-migration TB screening, namely the United Kingdom and Australia. The authors point out that both countries have developed strong health information system not only to collect and analyse screening results, but also to use the data to effectively monitor and evaluate the screening programme itself. The critical role which health information system plays within pre-migration screening is often overlooked. Here we argue that Japan, as with any other countries planning to introduce pre-migration screening for TB, must also plan for data management.

COVID-19: Exposing and addressing health disparities among ethnic minorities and migrants

COVID-19 disproportionately affects vulnerable and marginalized populations such as ethnic minorities and migrant groups. In this perspective we review the complex interaction of the many factors driving these inequities and suggest several possible solutions to mitigate the negative impact of COVID-19 on these populations.

Tuberculosis in migrants - screening, surveillance and ethics

Tuberculosis (TB) is the leading infectious cause of human mortality and is responsible for nearly 2 million deaths every year. It is often regarded as a ‘silent killer’ because it predominantly affects the poor and marginalized, and disease outbreaks occur in ‘slow motion’ compared to Ebola or coronavirus 2 (COVID-19). In low incidence countries, TB is predominantly an imported disease and TB control in migrants is pivotal for countries to progress towards TB elimination in accordance with the World Health Organisations (WHO’s) End TB strategy. This review provides a brief overview of the different screening approaches and surveillance processes that are in place in low TB incidence countries. It also includes a detailed discussion of the ethical issues related to TB screening of migrants in these settings and the different interests that need to be balanced. Given recognition that a holistic approach that recognizes and respects basic human rights is required to end TB, the review considers the complexities that require consideration in low-incidence countries that are aiming for TB elimination.

Linkages between land cover change, lake shrinkage, and sublacustrine influence determined from remote sensing of select Rift Valley Lakes in Kenya

The Great Rift Valley system is home to many volcanic and tectonic lakes including some of the world's oldest and deepest lakes. These lakes host a rich heritage of biodiversity that is endangered by recent drastic hydrologic changes due to multiple natural and anthropogenic stressors in the catchment areas of some of the lakes. This study utilized Landsat TM, ETM+, and OLI data to conduct a systematic investigation of the relationship between hydrological dynamics in the basins of four Rift Valley lakes (Nakuru, Baringo, Bogoria, and Elementaita) and recent land cover and land-use change. The Modified Normalized Difference Water Index (MNDWI) proved to be more accurate and robust for delineating water surface areas when compared to the output of Normalized Difference Vegetation Index (NDVI) and classification algorithms. NDVI was successful when delineating water surface at Lake Baringo but not in Lakes Bogoria, Nakuru, and Elementaita, whose surfaces were dominated by algae. All the lakes expanded substantially after 2010 submerging surrounding areas leading to disruption of livelihoods, property damage, and displacement of thousands of people. The recent drastic hydrologic changes have multiple causations including land cover and land use change, increase in rainfall, and possible change in geogenic water input due to tectonic activity. The rapid rise in water levels appears to have altered the biogeochemical balance of the hypersaline lakes with severe ramifications on the rich biodiversity that is supported by the lakes.

Estimating Aspergillus fumigatus exposure from outdoor composting activities in England between 2005 and 14

Bioaerosols, ubiquitous in ambient air, are released in elevated concentrations from composting facilities with open-air processing areas. However, spatial and temporal variability of bioaerosols, particularly in relation to meteorology, is not well understood. Here we model relative concentrations of Aspergillus fumigatus at each postcode-weighted centroid within 4 km of 217 composting facilities in England between 2005 and 2014. Facilities were geocoded with the aid of satellite imagery. Data from existing bioaerosol modelling literature were used to build emission profiles in ADMS. Variation in input parameters between each modelled facility was reduced to a minimum. Meteorological data for each composting facility was derived from the nearest SCAIL-Agriculture validated meteorological station. According to our results, modelled exposure risk was driven primarily by wind speed, direction and time-varying emissions factors incorporating seasonal fluctuations in compostable waste. Modelled A.fumigatus concentrations decreased rapidly from the facility boundary and plateaued beyond 1.5-2.0 km. Where multiple composting facilities were within 4 km of each other, complex exposure risk patterns were evident. More long-term bioaerosol monitoring near facilities is needed to help improve exposure estimation and therefore assessment of any health risks to local populations.

Screening for tuberculosis in migrants and visitors from high-incidence settings: present and future perspectives

In most settings with a low incidence of tuberculosis (TB), foreign-born people make up the majority of TB cases, but the distribution of the TB risk among different migrant populations is often poorly quantified. In addition, screening practices for TB disease and latent TB infection (LTBI) vary widely. Addressing the risk of TB in international migrants is an essential component of TB prevention and care efforts in low-incidence countries, and strategies to systematically screen for, diagnose, treat and prevent TB among this group contribute to national and global TB elimination goals.This review provides an overview and critical assessment of TB screening practices that are focused on migrants and visitors from high to low TB incidence countries, including pre-migration screening and post-migration follow-up of those deemed to be at an increased risk of developing TB. We focus mainly on migrants who enter the destination country via application for a long-stay visa, as well as asylum seekers and refugees, but briefly consider issues related to short-term visitors and those with long-duration multiple-entry visas. Issues related to the screening of children and screening for LTBI are also explored.

Cross-border collaboration for improved tuberculosis prevention and care: policies, tools and experiences

As tuberculosis (TB) spreads beyond borders with people movements, several interventions ensuring the continuity of care are essential, although difficult to put in place in the absence of well-defined agreements allowing data sharing and easy referral of patients to appropriate health facilities. This article first sets out general principles for cross-border collaboration and continuity of care. It then presents a series of case studies. Policies and practices on cross-border collaboration in selected low-incidence countries (Australia, Italy, Norway, The Netherlands, the United Kingdom and the United States) are described and critically appraised. Details of the World Health Organization's (WHO's) European Respiratory Society TB Consilium for transborder migration and those of the Health Network's TBNet activities are described. With increasing population movement, including migrants and travellers, it is time to build on good practices and existing tools and to remove legal, financial and social barriers to ensure early diagnosis, full treatment and continuity of care across our world. Data sharing between the sending and the receiving countries is of utmost importance and must be conducted in line with privacy protection rules. Successful implementation of these interventions is key to being on track with the WHO's End TB strategy targets for 2030.

Use of dispersion modelling for Environmental Impact Assessment of biological air pollution from composting: Progress, problems and prospects

With the increase in composting asa sustainable waste management option, biological air pollution (bioaerosols) from composting facilities have become a cause of increasing concern due to their potential health impacts. Estimating community exposure to bioaerosols is problematic due to limitations in current monitoring methods. Atmospheric dispersion modelling can be used to estimate exposure concentrations, however several issues arise from the lack of appropriate bioaerosol data to use as inputs into models, and the complexity of the emission sources at composting facilities. This paper analyses current progress in using dispersion models for bioaerosols, examines the remaining problems and provides recommendations for future prospects in this area. A key finding is the urgent need for guidance for model users to ensure consistent bioaerosol modelling practices.

Tuberculosis notifications in Australia, 2014

In 2014, the National Notifiable Diseases Surveillance System received 1,339 tuberculosis (TB) notifications, representing a rate of 5.7 per 100,000 population. Australia has achieved and maintained good tuberculosis (TB) control since the mid-1980s, sustaining a low annual TB incidence rate of approximately 5 to 6 cases per 100,000 population. The number of multi-drug resistant TB (MDR-TB) cases diagnosed in Australia is low by international standards, with approximately 1-2% of notifications per year being classified as MDR-TB. Australia's overseas-born population continued to represent the majority (86%) of TB notifications and Australia's Aboriginal and Torres Strait Islander population continue to record TB rates around 6 times higher than the Australian born non Indigenous population. Whilst Australia has achieved excellent and sustained control of TB in Australia, sustained effort is still required to reduce rates further and contribute to the achievement of the World Health Organization's goal to end the global TB epidemic by 2035.

Capacity strengthening through pre-migration tuberculosis screening programmes: IRHWG experiences

Effective tuberculosis (TB) prevention and care for migrants requires population health-based approaches that treat the relationship between migration and health as a progressive, interactive process influenced by many variables and addressed as far upstream in the process as possible. By including capacity building in source countries, pre-migration medical screening has the potential to become an integral component of public health promotion, as well as infection and disease prevention, in migrant-receiving nations, while simultaneously increasing capabilities in countries of origin. This article describes the collaborative experiences of five countries (Australia, Canada, New Zealand, United Kingdom and the United States of America, members of the Immigration and Refugee Health Working Group [IRHWG]), with similar pre-migration screening programmes for TB that are mandated. Qualitative examples of capacity building through IRHWG programmes are provided. Combined, the IRHWG member countries screen approximately 2 million persons overseas every year. Large-scale pre-entry screening programmes undertaken by IRHWG countries require building additional capacity for health care providers, radiology facilities and laboratories. This has resulted in significant improvements in laboratory and treatment capacity, providing availability of these facilities for national public health programmes. As long as global health disparities and disease prevalence differentials exist, national public health programmes and policies in migrant-receiving nations will continue to be challenged to manage the diseases prevalent in these migrating populations. National TB programmes and regulatory systems alone will not be able to achieve TB elimination. The management of health issues resulting from population mobility will require integration of national and global health initiatives which, as demonstrated here, can be supported through the capacity-building endeavours of pre-migration screening programmes.

Effectiveness and safety of bedaquiline-containing regimens in the treatment of MDR- and XDR-TB: a multicentre study

Large studies on bedaquiline used to treat multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) are lacking. This study aimed to evaluate the safety and effectiveness of bedaquiline-containing regimens in a large, retrospective, observational study conducted in 25 centres and 15 countries in five continents.428 culture-confirmed MDR-TB cases were analysed (61.5% male; 22.1% HIV-positive, 45.6% XDR-TB). MDR-TB cases were admitted to hospital for a median (interquartile range (IQR)) 179 (92-280) days and exposed to bedaquiline for 168 (86-180) days. Treatment regimens included, among others, linezolid, moxifloxacin, clofazimine and carbapenems (82.0%, 58.4%, 52.6% and 15.3% of cases, respectively).Sputum smear and culture conversion rates in MDR-TB cases were 63.6% and 30.1%, respectively at 30 days, 81.1% and 56.7%, respectively at 60 days; 85.5% and 80.5%, respectively at 90 days and 88.7% and 91.2%, respectively at the end of treatment. The median (IQR) time to smear and culture conversion was 34 (30-60) days and 60 (33-90) days. Out of 247 culture-confirmed MDR-TB cases completing treatment, 71.3% achieved success (62.4% cured; 8.9% completed treatment), 13.4% died, 7.3% defaulted and 7.7% failed. Bedaquiline was interrupted due to adverse events in 5.8% of cases. A single case died, having electrocardiographic abnormalities that were probably non-bedaquiline related.Bedaquiline-containing regimens achieved high conversion and success rates under different nonexperimental conditions.

Sensitivity of predicted bioaerosol exposure from open windrow composting facilities to ADMS dispersion model parameters

Bioaerosols are released in elevated quantities from composting facilities and are associated with negative health effects, although dose-response relationships are not well understood, and require improved exposure classification. Dispersion modelling has great potential to improve exposure classification, but has not yet been extensively used or validated in this context. We present a sensitivity analysis of the ADMS dispersion model specific to input parameter ranges relevant to bioaerosol emissions from open windrow composting. This analysis provides an aid for model calibration by prioritising parameter adjustment and targeting independent parameter estimation. Results showed that predicted exposure was most sensitive to the wet and dry deposition modules and the majority of parameters relating to emission source characteristics, including pollutant emission velocity, source geometry and source height. This research improves understanding of the accuracy of model input data required to provide more reliable exposure predictions.

Hydration education: developing, piloting and evaluating a hydration education package for general practitioners

OBJECTIVES

To (1) assess the hydration knowledge, attitudes and practices (KAP) of doctors; (2) develop an evidence-based training package; and (3) evaluate the impact of the training package.

DESIGN

Educational intervention with impact evaluation.

SETTING

Cambridgeshire, UK.

PARTICIPANTS

General practitioners (GPs (primary care physicians)).

INTERVENTIONS

Hydration and healthcare training.

MAIN OUTCOME MEASURES

Hydration KAP score before and immediately after the training session.

RESULTS

Knowledge gaps of doctors identified before the teaching were the definition of dehydration, European Food Safety Authority water intake recommendations, water content of the human body and proportion of water from food and drink. A face-to-face teaching package was developed on findings from the KAP survey and literature search. 54 questionnaires were completed before and immediately after two training sessions with GPs. Following the training, total hydration KAP scores increased significantly (p<0.001; median (25th, 75th centiles); 32 (29, 34)). Attendees rated the session as excellent or good (90%) and reported the training was likely to influence their professional practice (100%).

CONCLUSIONS

The training package will continue to be developed and adapted, with increased focus on follow-up strategies as well as integration into medical curricula and standards of practice. However, further research is required in the area of hydration care to allow policymakers to incorporate hydration awareness and care with greater precision in local and national policies.

Proceedings of the inaugural International Summit for Medical Nutrition Education and Research

Medical Nutrition Education (MNE) has been identified as an area with potential public health impact. Despite countries having distinctive education systems, barriers and facilitators to effective MNE are consistent across borders, demanding a common platform to initiate global programmes. A shared approach to supporting greater MNE is ideal to support countries to work together. In an effort to initiate this process, the Need for Nutrition Education/Innovation Programme group, in association with their strategic partners, hosted the inaugural International Summit on Medical Nutrition Education and Research on August 8, 2015 in Cambridge, UK. Speakers from the UK, the USA, Canada, Australia, New Zealand, Italy, and India provided insights into their respective countries including their education systems, inherent challenges, and potential solutions across two main themes: (1) Medical Nutrition Education, focused on best practice examples in competencies and assessment; and (2) Medical Nutrition Research, discussing how to translate nutrition research into education opportunities. The Summit identified shared needs across regions, showcased examples of transferrable strategies and identified opportunities for collaboration in nutrition education for healthcare (including medical) professionals. These proceedings highlight the key messages presented at the Summit and showcase opportunities for working together towards a common goal of improvement in MNE to improve public health at large.

The epidemiology of tuberculosis in children in Australia, 2003-2012

OBJECTIVE

To describe the burden of and trends in paediatric tuberculosis (TB) in Australia between 2003 and 2012.

DESIGN

A retrospective analysis of TB data from the National Notifiable Diseases Surveillance System (NNDSS) on TB in children (under 15 years of age) during the 10-year period, 2003-2012.

RESULTS

TB notifications in Australia during the study period included 538 children (range, 37-66 cases per year), representing 4.6% of the total TB case load during the period (range, 3.8%-5.8% each year). Place of birth was recorded for 524 patients (97.4%); of these, 230 (43.9%) were born in Australia, 294 (56.1%) overseas. The average annual notification rate was 1.31 (95% CI, 1.20-1.43) cases per 100 000 child population. The rate was higher for overseas-born than for Australian-born children (9.57 [95% CI, 8.51-10.73] v 0.61 [95% CI, 0.53-0.69] cases per 100 000 children. The overall rate was highest among those aged 0-4 years. The annual notification rate was three times higher for Indigenous children than for non-Indigenous Australian-born children. Of 427 patients (79.4% of total) for whom the method of case detection was recorded, 37.0% were detected by contact screening, 8.7% by post-arrival immigration screening, and 54.3% by passive case detection. Pulmonary TB was the most common diagnostic classification (64.7% of patients). The most common risk factors were close contact with a TB case and recent residence in a country with a high incidence of TB. Treatment outcomes were satisfactory; 89.4% of children had completed treatment or were cured.

CONCLUSIONS

The burden of paediatric TB in Australia is low but has not changed over the past decade. The highest rates are among children born overseas, emphasising the important role of immigration screening as Australia aspires to eliminate TB.

Tuberculosis notifications in Australia, 2012 and 2013

The National Notifiable Diseases Surveillance System received 1,317 tuberculosis (TB) notifications in 2012 and 1,263 notifications in 2013. This represents a rate of 5.8 per 100,000 population in 2012 and 5.5 per 100,000 population in 2013 and a reversal of the upward trend in TB incidence reported since 2007. In 2012 and 2013, Australia's overseas-born population continued to represent the majority of TB notifications with an incidence rate of 19.5 per 100,000 and 18.4 per 100,000 respectively. The incidence of TB in the Australian-born Indigenous population has fluctuated over the last decade; however, it remained reasonably steady in 2012 and 2013 with an incidence rate of 4.5 per 100,000 and 4.6 per 100,000 respectively. The incidence of TB in the Australian-born non-Indigenous population has continued to remain low at 0.7 per 100,000 in 2012 and 0.8 per 100,000 in 2013. Australia continued to record only a small number of multi-drug resistant TB cases nationally (2012: n=20; 2013: n=22) of which nearly all were identified in the overseas-born population. This report demonstrates excellent and sustained control of TB in Australia and reflects Australia's commitment to reducing the global burden of TB.

Cocaine-induced transmural myocardial infarction in a Yorkshire swine with normal coronary arteries: Evidence for microvascular and/or epicardial coronary artery spasm

Cocaine-induced myocardial infarction with normal coronary arteries is well documented in humans. The exact mechanism of action remains speculative. We report one case of cocaine-induced myocardial infarction with normal coronaries in one swine. Systemic hemodynamics and angiographic, electrocardiographic, echocardiographic, and histopathologic data are presented. Intravenous cocaine (1, 3, 10 mg/kg) produced significant decreases in mean arterial pressure, heart rate, stroke volume, coronary blood flow, and coronary reserve, whereas pulmonary artery diastolic pressure and coronary vascular resistances increased. Left anterior descending and left circumflex coronary artery cross-sectional area decreased by 31% and 64%, respectively, without localized vasospasm. Electrocardiographic changes occurred (3 mm ST elevation in leads II, III, AVF). Peak creatine phosphokinase was 17,220 IU/L. The echocardiogram revealed severe hypokinesis of the inferior wall and normal ventricular function. The animal survived the acute phase of the infarction and the swine was restudied 12 weeks later. Upon rechallenge, systemic and coronary hemodynamics shoved changes similar to those in the previous study. The swine developed ventricular fibrillation and expired after the 10 mg/kg cocaine dose. Macroscopic examination of the external surface of the heart revealed marked diffuse fibrosis in the posteroinferior and lateral left ventricular wall. Our data suggest that the infarct induced by cocaine may have resulted from severe vasoconstriction or spasm at the level of the microcirculation, and/or the epicardial coronary arteries, which shoved slight but significant narrowing throughout their lengths.

Towards tuberculosis elimination: an action framework for low-incidence countries

This paper describes an action framework for countries with low tuberculosis (TB) incidence (<100 TB cases per million population) that are striving for TB elimination. The framework sets out priority interventions required for these countries to progress first towards "pre-elimination" (<10 cases per million) and eventually the elimination of TB as a public health problem (less than one case per million). TB epidemiology in most low-incidence countries is characterised by a low rate of transmission in the general population, occasional outbreaks, a majority of TB cases generated from progression of latent TB infection (LTBI) rather than local transmission, concentration to certain vulnerable and hard-to-reach risk groups, and challenges posed by cross-border migration. Common health system challenges are that political commitment, funding, clinical expertise and general awareness of TB diminishes as TB incidence falls. The framework presents a tailored response to these challenges, grouped into eight priority action areas: 1) ensure political commitment, funding and stewardship for planning and essential services; 2) address the most vulnerable and hard-to-reach groups; 3) address special needs of migrants and cross-border issues; 4) undertake screening for active TB and LTBI in TB contacts and selected high-risk groups, and provide appropriate treatment; 5) optimise the prevention and care of drug-resistant TB; 6) ensure continued surveillance, programme monitoring and evaluation and case-based data management; 7) invest in research and new tools; and 8) support global TB prevention, care and control. The overall approach needs to be multisectorial, focusing on equitable access to high-quality diagnosis and care, and on addressing the social determinants of TB. Because of increasing globalisation and population mobility, the response needs to have both national and global dimensions.

Tuberculosis notifications in Australia, 2011

The National Notifiable Diseases Surveillance System received 1,385 tuberculosis (TB) notifications in 2011, representing a rate of 6.2 cases per 100,000 population. While Australia has maintained a rate of 5 to 6 cases per 100,000 for TB since the mid-1980s, there has been a steady increase in incidence over the past decade. In 2011, Australia's overseas-born population continued to represent the majority of TB notifications (88%) with a notification rate of 20.2 per 100,000. The incidence of TB in the Australian-born Indigenous population has fluctuated over the last decade and showed no clear trend; however, in 2011 the notification rate was 4.9 per 100,000, which is a notable decrease from the 7.5 per 100,000 recorded in 2010. The incidence of TB in the Australian-born non-Indigenous population has continued to remain low at 0.9 per 100,000. Australia continued to record only a small number of multi-drug-resistant TB (MDR-TB) cases nationally (n=25), all of which were identified in the overseas-born population. To ensure that Australia can retain its low TB rate and work toward reducing rates further, it is essential that Australia maintains good centralised national TB reporting to monitor trends and identify at-risk populations, and continues to contribute to global TB control initiatives.

The impact of prolonged violent video-gaming on adolescent sleep: an experimental study

Video-gaming is an increasingly prevalent activity among children and adolescents that is known to influence several areas of emotional, cognitive and behavioural functioning. Currently there is insufficient experimental evidence about how extended video-game play may affect adolescents' sleep. The aim of this study was to investigate the short-term impact of adolescents' prolonged exposure to violent video-gaming on sleep. Seventeen male adolescents (mean age = 16 ± 1 years) with no current sleep difficulties played a novel, fast-paced, violent video-game (50 or 150 min) before their usual bedtime on two different testing nights in a sleep laboratory. Objective (polysomnography-measured sleep and heart rate) and subjective (single-night sleep diary) measures were obtained to assess the arousing effects of prolonged gaming. Compared with regular gaming, prolonged gaming produced decreases in objective sleep efficiency (by 7 ± 2%, falling below 85%) and total sleep time (by 27 ± 12 min) that was contributed by a near-moderate reduction in rapid eye movement sleep (Cohen's d = 0.48). Subjective sleep-onset latency significantly increased by 17 ± 8 min, and there was a moderate reduction in self-reported sleep quality after prolonged gaming (Cohen's d = 0.53). Heart rate did not differ significantly between video-gaming conditions during pre-sleep game-play or the sleep-onset phase. Results provide evidence that prolonged video-gaming may cause clinically significant disruption to adolescent sleep, even when sleep after video-gaming is initiated at normal bedtime. However, physiological arousal may not necessarily be the mechanism by which technology use affects sleep.

Frequency stabilization of an external-cavity diode laser to metastable argon atoms in a discharge

A laser stabilization scheme using magnetic dichroism in a RF plasma discharge is presented. This method has been used to provide a frequency stable external-cavity diode laser that is locked to the 4s[3/2](2) → 4p[5/2](3) argon laser cooling transition at 811.53 nm. Using saturated absorption spectroscopy, we lock the laser to a Doppler free peak which gave a locking range of 20 MHz when the slope of the error signal was maximized. The stability of the laser was characterized by determining the square root Allan variance of laser frequency fluctuations when the laser was locked. A stability of 129 kHz was measured at 1 s averaging time for data acquired over 6000 s.

A comparative examination of tuberculosis immigration medical screening programs from selected countries with high immigration and low tuberculosis incidence rates

BACKGROUND

Tuberculosis (TB) in migrants is an ongoing challenge in several low TB incidence countries since a large proportion of TB in these countries occurs in migrants from high incidence countries. To meet these challenges, several countries utilize TB screening programs. The programs attempt to identify and treat those with active and/or infectious stages of the disease. In addition, screening is used to identify and manage those with latent or inactive disease after arrival. Between nations, considerable variation exists in the methods used in migration-associated TB screening. The present study aimed to compare the TB immigration medical examination requirements in selected countries of high immigration and low TB incidence rates.

METHODS

Descriptive study of immigration TB screening programs.

RESULTS

16 out of 18 eligible countries responded to the written standardized survey and phone interview. Comparisons in specific areas of TB immigration screening programs included authorities responsible for TB screening, the primary objectives of the TB screening program, the yield of detection of active TB disease, screening details and aspects of follow up for inactive pulmonary TB. No two countries had the same approach to TB screening among migrants. Important differences, common practices, common problems, evidence or lack of evidence for program specifics were noted.

CONCLUSIONS

In spite of common goals, there is great diversity in the processes and practices designed to mitigate the impact of migration-associated TB among nations that screen migrants for the disease. The long-term goal in decreasing migration-related introduction of TB from high to low incidence countries remains diminishing the prevalence of the disease in those high incidence locations. In the meantime, existing or planned migration screening programs for TB can be made more efficient and evidenced based. Cooperation among countries doing research in the areas outlined in this study should facilitate the development of improved screening programs.

Pediatric tuberculosis immigration screening in high-immigration, low-incidence countries

BACKGROUND

Tuberculosis (TB) screening in migrant children, including immigrants, refugees and asylum seekers, is an ongoing challenge in low TB incidence countries. Many children from high TB incidence countries harbor latent TB infection (LTBI), and some have active TB disease at the point of immigration into host nations. Young children who harbor LTBI have a high risk of progression to TB disease and are at a higher risk than adults of developing disseminated severe forms of TB with significant morbidity and mortality. Many countries have developed immigration TB screening programs to suit the needs of adults, but have not focused much attention on migrant children.

OBJECTIVE

To compare the TB immigration medical examination requirements in children in selected countries with high immigration and low TB incidence rates.

DESIGN

Descriptive study of TB immigration screening programs for systematically selected countries.

RESULTS

Of 18 eligible countries, 16 responded to the written survey and telephone interview.

CONCLUSION

No two countries had the same approach to TB screening among migrant children. The optimal evidenced-based manner in which to screen migrant children requires further research.

The effect of presleep video-game playing on adolescent sleep

STUDY OBJECTIVES

Video-game use before bedtime has been linked with poor sleep outcomes for adolescents; however, experimental evidence to support this link is sparse. The present study investigated the capacity of presleep video-game playing to extend sleep latency and reduce subjective feelings of sleepiness in adolescents. The arousing psychophysiologic mechanisms involved and the impact of presleep video-game playing on sleep architecture were also explored.

METHOD

Thirteen male adolescent "evening types" (mean age = 16.6 years, SD = 1.1) participated in a counterbalanced, within-subjects design with experimental (active video gaming) and control (passive DVD watching) conditions. The experiment was conducted in the Flinders University Sleep Research Laboratory.

RESULTS

Relative to the control condition, presleep video-game playing increased sleep-onset latency (Z= 2.45, p= .01) and reduced subjective sleepiness (Z = 2.36, p = .02)-but only slightly. Video gaming was related to changes in cognitive alertness (as measured by a power: p < 0.01) but not physiologic arousal (as measured by heart rate: p > 0.05). Contrary to previous findings, sleep architecture was unaffected (both rapid eye movement and slow wave sleep: p > 0.05).

CONCLUSIONS

Results suggest the direct effect of presleep video-game playing on adolescent sleep may be more modest than previously thought, suggesting that surveys linking stimulating presleep activities to poor sleep need substantiating with empirical evidence.