Are French local health contracts promising in addressing determinants of diet and physical activity?

Background

There is a consensus on the need to transform the built, economic and socio-cultural environments to promote healthy eating (HE) and physical activity (PA). Yet, limited capacity and the biomedicalisation of public health are often blamed for steering investments towards individual risk factors. In France, local health contracts (LHCs) agreed between a regional health agency (RHA) and a local government could improve health promotion strategies. We examined how LHCs take into account the environmental determinants of HE and PA.

Methods

Using the CLoterreS national census, we analysed a stratified random sample of 53 LHCs with a view to identify if actions target individual (knowledge, skills, etc.) or environmental (interpersonal, organisational, community or political) determinants. To this end, we developed an instrument drawing from different typologies of action and consensus documents to assess the integration of the socioecological approach in programmes. We ran a series of interviews with RHA staff (n = 39) and local actors (n = 23) to put into context our results.

Results

Out of 53 LHCs, 42 included at least one action on HE or PA. For these topics, there was a higher proportion of actions targeting individuals (83% and 76% per contract, respectively) than environments (51% and 58%). For the latter, actions on interpersonal determinants (e.g. family) were the most common. However, we also found instances of actions on more distal ones (e.g. to improve nutrition standards in school canteens and walkability). Contextual factors such as local priorities, past experience with health promotion and the involvement of local actors in needs assessment and action planning may influence such orientations.

Conclusions

LHCs constitute a promising avenue to address the environmental determinants of health-related behaviours. A key feature of this instrument is its capacity to develop intersectoral strategies. Further research will show if LHCs deliver on their action plan.

Key messages

• Local health contracts facilitate the mobilisation of a broad diversity of NGOs and agencies.

• This makes it a promising device for addressing the environmental determinants of HE and PA, provided adequate resources are devoted to stakeholder engagement and local government capacity-building.

Immunoinflammatory processes: Overlapping mechanisms between obesity and eating disorders?

Obesity and eating disorders are conditions that involve eating behaviors and are sometimes comorbid. Current evidence supports alterations in immunoinflammatory processes in both obesity and eating disorders. A plausible hypothesis is that immunoinflammatory processes may be involved in the pathophysiology of obesity and eating disorders. The aim of this review is to highlight the link between obesity and eating disorders, with a particular focus on immunoinflammatory processes. First, the relation between obesity and eating disorders will be presented, followed by a brief review of the literature on their association with immunoinflammatory processes. Second, developmental factors will be discussed to clarify the link between obesity, eating disorders, and immunoinflammatory processes. Genetic and epigenetic risk factors as well as the potential roles of stress pathways and early life development will be presented. Finally, implications of these findings for future research are discussed. This review highlighted biological and developmental aspects that overlap between obesity and EDs, emphasizing the need for biopsychosocial research approaches to advance current knowledge and practice in these fields.

Biomedical detection dogs for the identification of SARS-CoV-2 Infections from axillary sweat and breath samples

A PCR test of a nasal swab is still the "gold standard" for detecting a SARS-CoV-2 infection. However, PCR testing could be usefully complemented by non-invasive, fast, reliable, cheap methods for detecting infected individuals in busy areas (e.g. airports and railway stations) or remote areas. Detection of the volatile, semivolatile and non-volatile compound signature of SARS-CoV-2 infection by trained sniffer dogs might meet these requirements. Previous studies have shown that well-trained dogs can detect SARS-CoV-2 in sweat, saliva and urine samples. The objective of the present study was to assess the performance of dogs trained to detect the presence of SARS-CoV-2 in axillary-sweat-stained gauzes and on expired breath trapped in surgical masks. The samples were provided by individuals suffering from mild-to-severe coronavirus disease 2019 (COVID-19), asymptomatic individuals, and individuals vaccinated against COVID-19. Results: Seven trained dogs tested on 886 presentations of sweat samples from 241 subjects and detected SARS-CoV-2 with a diagnostic sensitivity (relative to the PCR test result) of 89.6% (95% confidence interval (CI): 86.4-92.2%) and a specificity of 83.9% (95% CI: 80.3-87.0%) - even when people with a low viral load were included in the analysis. When considering the 207 presentations of sweat samples from vaccinated individuals, the sensitivity and specificity were respectively 85.7% (95% CI: 68.5-94.3) and 86.0% (95% CI: 80.2-90.3%). The likelihood of a false-positive result was greater in the two weeks immediately after COVID-19 vaccination. Four of the seven dogs also tested on 262 presentations of mask samples from 98 subjects; the diagnostic sensitivity was 83.1% (95% CI: 73.2-89.9) and the specificity was 88.6% (95% CI: 83.3-92.4%). There was no difference (McNemar's test P=0.999) in the dogs' abilities to detect the presence of SARS-CoV-2 in paired samples of sweat-stained gauzes vs. surgical masks worn for only 10 minutes. Conclusion: Our findings confirm the promise of SARS-CoV-2 screening by detection dogs and broaden the method's scope to vaccinated individuals and easy-to-obtain face masks, and suggest that a "dogs + confirmatory rapid antigen detection tests" screening strategy might be worth investigating.

Identifying SARS-COV-2 infected patients through canine olfactive detection on axillary sweat samples; study of observed sensitivities and specificities within a group of trained dogs

There is an increasing need for rapid, reliable, non-invasive, and inexpensive mass testing methods as the global COVID-19 pandemic continues. Detection dogs could be a possible solution to identify individuals infected with SARS-CoV-2. Previous studies have shown that dogs can detect SARS-CoV-2 on sweat samples. This study aims to establish the dogs’ sensitivity (true positive rate) which measures the proportion of people with COVID-19 that are correctly identified, and specificity (true negative rate) which measures the proportion of people without COVID-19 that are correctly identified. Seven search and rescue dogs were tested using a total of 218 axillary sweat samples (62 positive and 156 negative) in olfaction cones following a randomised and double-blind protocol. Sensitivity ranged from 87% to 94%, and specificity ranged from 78% to 92%, with four dogs over 90%. These results were used to calculate the positive predictive value and negative predictive value for each dog for different infection probabilities (how likely it is for an individual to be SARS-CoV-2 positive), ranging from 10–50%. These results were compared with a reference diagnostic tool which has 95% specificity and sensitivity. Negative predictive values for six dogs ranged from ≥98% at 10% infection probability to ≥88% at 50% infection probability compared with the reference tool which ranged from 99% to 95%. Positive predictive values ranged from ≥40% at 10% infection probability to ≥80% at 50% infection probability compared with the reference tool which ranged from 68% to 95%. This study confirms previous results, suggesting that dogs could play an important role in mass-testing situations. Future challenges include optimal training methods and standardisation for large numbers of detection dogs and infrastructure supporting their deployment.

Public health lessons from the soda taxes enacted in France in 2012 and modified in 2018

Background

In 2016, the WHO officially recommended sugar-sweetened beverage (SSB) taxation as a strategy to reduce consumption, stimulate product reformulation and generate revenues for health-related programmes. This recommendation was based on a number of studies and experiments amongst them the 2012 French SSB tax that was redesigned in 2018. In this presentation, we summarize the lessons learnt from the soda taxes in France and offer insights on their potential public health benefits.

Methods

Our rationale is structured according to the interdisciplinary perspective of the Soda-Tax research consortium (2019-2023), addressing: (1) the soda tax policy change process; (2) the impact on price and purchases; (3) the consumer receptiveness to the tax and; (4) its legal framework and potential application to other foods/nutrients.

Results

Our overview of evidence highlights that the process leading to the enactment of the 2012 tax was initially based on a public health justification that was later set aside in favour of budgetary concerns. The tax, whose rate was flat and low and whose scope was extended to artificially-sweetened drinks containing no added sugar, generated modest effects on SSB consumption. Yet, it was ground breaking and offered an opportunity to appreciate its equity, to document its acceptance through a population-based survey and its legal viability. Six years later, the new tax comes closer to international recommendations: it is framed within the scope of public health action, focuses on SSBs and its rate is indexed to the quantity of added sugar in the drink.

Conclusions

The Soda-Tax project will study the degree of policy learning that may have contributed to the evolution of the 2018 tax, as well as the conditions of its implementation, administratively more complex than the previous one. It will also explore the social acceptability of this new tax and the extent to which it results in higher SSB prices, lower consumption and changes in the market.

Key messages

The design of the 2012 French soda tax was not optimal for public health, but it set a precedent. The 2018 soda tax, closer to international recommendations, deserves further investigation.

The application of the complexity theory to public health interventions: a review of the literature

Background

There is a growing recognition of the limitations of a linear cause-and-effect rationality in planning and evaluating public health interventions. Although this perspective is amenable to programme planning and evaluation, it leaves aside a whole array of mechanisms of change triggered by interactions taking place in complex social systems. Generative causality is one and recognized under a number of works referring to the complexity paradigm. Here we review the state of knowledge on what is often referred to as the complexity theory (CT), and present the results of a review of the literature on its application in public health.

Methods

We searched PubMed for articles, commentaries, editorials published in English, French and Italian, using the keywords 'Complexity Theory' (also plural). We categorized the fields of application of the CT according to the three core WHO's Essential Public Health Operations, i.e., Health Promotion, Prevention and Protection. All papers addressing issues related to health care services (but not prevention) were included in the category “health care services” while others were tagged as “others”.

Results

We found 203 papers meeting our inclusion criteria. The largest share of the research output applying the CT was in health care services (n = 167), followed by Health Promotion (5), Prevention (3) and Protection (2). 26 papers were labelled others. In health promotion/ prevention, applications of the CT have yet to integrate most of its concepts. Most authors tap into both the linear and generative rationality perspectives.

Conclusions

Although regularly deemed as promising in uncovering mechanisms for change triggered by public health intervention, applications of the complexity theory remain uncommon and has made little inroads in the public health domain. This is particularly the case for health promotion where one would assume that participatory community-based interventions would be an incentive to integrate this perspective.

Key messages

Although deemed promising the complexity theory has made little inroads in public health. Health promotion with its participatory community-based interventions can benefit from its application.

Local health contracts as instruments of cross-sectoral collaboration: the French CLoterreS study

Background

Although recognised as essential, the role of local governments in promoting health remains under investigated. Yet their mandate directly impacts living conditions and promotes SDGs. In France, 'local health contracts' (LHCs) mobilise local decision-makers in 4 areas: health promotion, prevention, health care and social care. The CLoterreS study assesses the extent to which LHCs foster health-promoting actions through cross-sectoral collaboration.

Methods

We conducted 49 semi-structured interviews with staff from all Regional health agencies (RHAs) and local stakeholders. We analysed the action plans of a stratified random sample of 53 LHCs from the 165 signed between 2015 and March 2018. We used a validated multidimensional coding tool based on WHO's Essential Public Health Operations and other consensus documents.

Results

LHC's contribution to health promotion through cross-sectoral collaboration depends on a mix of factors. Among barriers, the improvement of access to health care is often a primary driver for local elected officials. However, political will and past experience in establishing 'win-win' relationships with other sectors is an advantage, as well as the fact that RHAs generally make LHCs an instrument to coordinate health promotion efforts instead of ad hoc funding of isolated actions. Overall, 73% of LHCs' actions address living conditions, health promotion or primary prevention. LHCs frequently target behavioural determinants such as physical activity or diet (44 out of 53) with an emphasis on individual or interpersonal targets. A few innovative actions situated at the intersection of urban planning, transportation, recreational or food environments illustrate the potential for further cross-sectoral action on living conditions.

Conclusions

LHCs are vehicles for health promotion. Reinforcing cross-sectoral action implies leadership, resource mobilisation, training and coordination of sectors whose health is not a core priority.

Key messages

In France, Local health contracts (LHCs) are significantly used for health promotion. Cross-sectoral collaboration in this area implies further capacity building beyond the health care sector at the regional and local levels.

How the French Nutri-Score can impact sales of processed-foods? A complex system perspective

Background

Nutri-Score (NS) is France Front-of-Pack Food Labelling System to provide at-a-glance information about the nutritional quality of pre-packaged food products. Based on the Food Standards Agency nutrient profiling system, its algorithm generates a score by taking into account the presence of both the harmful and beneficial contents in food. In this presentation, we report on our analysis of the logic model of NS and on its potential impact on the production and marketing of processed foods.

Methods

We reviewed the scientific and grey literature on NS to identify its potential mechanisms and loci of change. We also appraised the policy against Meadow’s leverage points for system change.

Results

The official adoption of the NS algorithm is instrumental in modifying both consumer food-related behaviours and food industry corporate practices. The algorithm takes 3 forms: 1) the front-of-pack logo indicating an integrated colour/letter score for the product, 2) mobile device applications which help consumers assess the nutritional value of food products even without an affixed logo, 3) nutritional parameters which influence food manufacturing decision-making in the industry. NS can trigger different drivers of corporate practice. From the current uptake trends, small and medium size food manufacturers appear more likely to welcome the NS Logo as a means to stand out against the multinational corporations presently dominating the market. As for the capacity of NS to transform the existing systems of producing and marketing processed foods, we find that it is mostly by changing the flow of information. NS presents new information, previously inaccessible to consumers, to support the population in making healthier food choices by providing a means for nuanced nutritional comparisons between food products of the same category.

Conclusions

We conclude on the potential evolution of Nutri-Score and how its uptake by food corporations may be fostered.

Key messages

Nutri-Score’s impact is through: the front-of-pack logo; nutrition apps; and as a parameter of food industry decision-making. Nutri-Score impacts the flow of information of the processed-food system.

Analysing local public health action plans: development of a tool for the French CLoterreS Study

Background

The potential contribution of local authorities to prevention and health promotion is well recognized. In France, since 2009, Local Health Contracts (LHCs) are mobilising Regional Health Agencies, local elected officials and stakeholders to intervene in 4 areas: health promotion, prevention, health care and social care. LHCs remain poorly documented policy instruments.

Methods

As part of the CLoterreS study, a multidimensional coding tool was developed and tested by two coders to explore the place of prevention and health promotion in LHCs. Its development was based on the WHO conceptual framework for action on the social determinants of health and the Self-assessment tool for the evaluation of essential public health operations in the WHO European Region. Preliminary results concern a random sample of 17 LHCs from as many French regions selected among the 165 LHCs signed between 2015 and March 2018.

Results

On average, the LHCs featured 26 action forms (AF) (min: 5; max: 56). In a LHC, the average proportion of AF addressing either the social determinants of health, living circumstances or other determinants targeted by health protection, promotion or primary prevention interventions (SDoH-HPP-P1) was 79% while 44% of the AF address secondary/tertiary prevention, social care or the organization of health care and services. Among the SDoH-HPP-P1 themes (double coding permitted): psychosocial life circumstances were addressed in the 17 LHCs and concerned, on average, 31% of their AF; material living circumstances were addressed to a lesser extent (16 LHCs, 13%); other key themes include environmental health (12, 14%), mental health (16, 12%), alcohol abuse (15, 11%), drug use (14, 11%), smoking (13, 9%), physical activity (13, 12%), healthy eating (12, 12%).

Conclusions

This work confirms that LHCs are instruments with prevention and health promotion at their core. Explanation of the differing investments in this area across our sample will be further explored.

Key messages

Local Health Contracts are promising instruments to address locally a broad range of health determinants. The CLoterreS analytical tool has proven effective in capturing multiple themes and shedding light on differences between Local Health Contracts’ action plans.

Placental NEGR1 DNA methylation is associated with BMI and neurodevelopment in preschool-age children

Studies have linked maternal pre-pregnancy obesity and hyperglycaemia with metabolic and neurodevelopmental complications in childhood. DNA methylation (DNAm) might enable foetal adaptations to environmental adversities through important gene loci. NEGR1 is involved in both energy balance and behaviour regulation. The aim of this study was to investigate associations between placental DNAm at the NEGR1 gene locus and childhood anthropometric and neurodevelopmental profiles in preschoolers. We analysed 276 mother-child dyads from Gen3G, a prospective birth cohort from Sherbrooke. At 3yo (40.4 ± 3.0 months), we measured body mass index (BMI) and the mothers reported on offspring neurobehavior using the Strengths and Difficulties Questionnaire (SDQ). We quantified DNAm levels at 30 CpGs at the NEGR1 locus using the MethylationEPIC Array in placental biopsies. DNAm at four CpGs located before NEGR1 second exon predicted child's BMI z-score (cg26153364: β=-0.16 ± 0.04; p=0.008, cg23166710: β=0.14 ± 0.08; p=0.03) and SDQ total score (cg04932878: β=0.22 ± 1.0; p= 3.0x10^-4, cg16525738: β=-0.14 ± 0.18; p=0.01, cg23166710: β=-0.13 ± 0.36; p= 0.04), explaining 4.2% (p=0.003) and 7.3% (p= 1.3 x 10^-4) of BMI-z and SDQ variances. cg23166710 was associated with both childhood phenotypes and correlated with NEGR1 placental expression (r=-0.22, p=0.04), suggesting its possible functional role. Together, maternal metabolic characteristics during pregnancy with NEGR1 DNAm levels explained 7.4% (p=4.2 x 10^-4) of BMI-z and 14.2% (p=2.8 x 10^-7) of SDQ variance at 3yo. This longitudinal study suggests that placental NEGR1 DNAm is associated with adiposity and neurodevelopment in preschool children and highlights its potential role in their comorbidity.

Preclinical evaluation of the atraumatic nature of a spring loaded blunt tip coaxial needle in a swine model

PURPOSE

To test in vivo in an animal model the inherent atraumatic characteristics of the spring loaded blunt tip of a coaxial needle (Gangi-SoftGuard®, Apriomed, Sweden) against a conventional sharp stylet coaxial needle.

MATERIAL AND METHODS

The study was conducted on a 40kg male swine that was its own control for a vascular trauma model. The procedure consisted of voluntary attempts to transfix and traverse the artery/aorta under continuous real-time angiogram. Test and control needles were positioned in the region of the intercostal, superior mesenteric and femoral/deep femoral arteries, and in the aorta. Computed tomography (CT) angiogram was performed post trauma to check for bleeding in the form of extravasation of contrast material. One attempt was performed per site and needle, except for the intercostal artery where a second attempt was done with the test needle, resulting in a total of 4 and 5 tests for the control and test needles, respectively.

RESULTS

With the spring loaded blunt tip, no vascular trauma or bleeding was noted in the intercostal, superior mesenteric and femoral arteries, nor in the aorta. Vascular spasm that recovered with time was noted during the second attempt to transfix the same intercostal artery. There were consistent vascular traumas and bleedings with the control needle in all three tested arteries and the aorta, confirmed on angiogram as well as CT angiogram.

CONCLUSION

The atraumatic feature offered by the spring loaded blunt tip prevented vascular trauma during the 5 attempts made to transfix the artery/aorta in a swine.

Evaluation d’impact sur la santé et évaluation d’impact sur l’équité en santé : éventail de pratiques et questions de recherche

L’Evaluation d’Impact sur la Santé (EIS) se développe au niveau international et est encore au stade émergent en France. Elle vise à évaluer les effets positifs et négatifs potentiels d’un projet, d’un programme ou d’une politique sur la santé. L’objectif est de produire des recommandations en direction des décideurs, afin d’en maximiser les effets positifs et d’en diminuer les effets négatifs. L’EIS est un moyen particulièrement intéressant d’action sur les déterminants de la santé au-delà des comportements individuels et du système de santé. Les politiques de logement, de transport, de solidarité, économiques, etc. ont, en effet, des impacts souvent non prévus sur la santé. Au-delà des effets sur la santé, l’EIS doit aussi permettre d’apprécier la distribution de ces effets dans la population.

Si la préoccupation pour l’équité en santé est centrale dans l’EIS, elle reste cependant difficilement traduite en pratique. Face à cette difficulté, des démarches d’évaluation d’impact ont été développées pour renforcer la prise en compte de l’équité à chaque étape de l’EIS ou « Equity Focused Health Impact Assessment », ou prendre en compte les impacts sur les inégalités de santé de façon spécifique. Ainsi, l’Evaluation de l’Impact sur l’Equité en Santé (EIES) semble, par exemple, particulièrement intéressante pour évaluer l’impact sur les inégalités de projets dans le champ sanitaire.

L’EIS et l’EIES posent de nombreuses questions de recherche, notamment autour de la réunion, dans une même démarche, du politique, du citoyen et de l’expert. La participation des populations vulnérables potentiellement affectées par la politique évaluée est une valeur centrale de l’EIS, mais pose des questions d’acceptabilité sociale. La collaboration avec les décideurs politiques est également un enjeu majeur. Les difficultés méthodologiques, notamment de quantification des impacts, peuvent constituer des freins à la promotion de la démarche auprès des décideurs.

Identifying main drivers and testing control strategies for CCHFV spread

Crimean Congo Haemorrhagic Fever (CCHF) is an emerging zoonotic disease. The causative agent is a virus (CCHFV), mainly transmitted by ticks of the species Hyalomma marginatum in Eastern Europe and Turkey. In order to test potential scenarios for the control of pathogen spread, the basic reproduction number (R0) for CCHF was calculated. This calculation was based on a population dynamics model and parameter values from the literature for pathogen transmission. The tick population dynamics model takes into account the major processes involved and gives estimates for tick survival from one stage to the other and number of feeding ticks. It also considers the influence of abiotic (meteorological variables) and biotic factors (host densities) on model outputs, which were compared with data collected in Central Anatolia (Turkey). R0 computation was thereafter used to test control strategies and especially the effect of acaricide treatment. Simulation results indicate that such treatments could have valuable effects provided that the acaricide is applied regularly throughout the spring and summer, and over several years. Furthermore, a sensitivity analysis to abiotic and biotic factors showed that, even though temperature has a strong impact on model outputs, host (mainly hare) densities also play a role. The kind of model we have developed provides insight into the ability of different strategies to prevent and control disease spread and has proved its relevance when associated with field trials.

MRI-Guided Percutaneous Biopsy of Mediastinal Masses Using a Large Bore Magnet: Technical Feasibility

OBJECTIVE

To evaluate the diagnostic accuracy and safety of magnetic resonance imaging (MRI)-guided percutaneous biopsy of mediastinal masses performed using a wide-bore high-field scanner.

MATERIALS AND METHODS

This is a retrospective study of 16 consecutive patients (8 male, 8 female; mean age 74 years) who underwent MRI-guided core needle biopsy of a mediastinal mass between February 2010 and January 2014. Size and location of lesion, approach taken, time for needle placement, overall duration of procedure, and post-procedural complications were evaluated. Technical success rates and correlation with surgical pathology (where available) were assessed.

RESULTS

Target lesions were located in the anterior (n = 13), middle (n = 2), and posterior mediastinum (n = 1), respectively. Mean size was 7.2 cm (range 3.6-11 cm). Average time for needle placement was 9.4 min (range 3-18 min); average duration of entire procedure was 42 min (range 27-62 min). 2-5 core samples were obtained from each lesion (mean 2.6). Technical success rate was 100%, with specimens successfully obtained in all 16 patients. There were no immediate complications. Histopathology revealed malignancy in 12 cases (4 of which were surgically confirmed), benign lesions in 3 cases (1 of which was false negative following surgical resection), and one inconclusive specimen (treated as inaccurate since repeat CT-guided biopsy demonstrated thymic hyperplasia). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in our study were 92.3, 100, 100, 66.7, and 87.5%, respectively.

CONCLUSION

MRI-guided mediastinal biopsy is a safe procedure with high diagnostic accuracy, which may offer a non-ionizing alternative to CT guidance.

[Knowledge of adolescents with inflammatory bowel disease: Results of a multicenter cross-sectional survey]

AIM

To assess knowledge acquired by adolescents about their inflammatory bowel disease (IBD).

METHODS

An anonymous questionnaire was given during consultation to adolescents followed for IBD by pediatricians from 13 hospitals between 1 September 2012 and 1 July 2013. After parental consent, these physicians completed a form at the inclusion of each patient, in which the characteristics of IBD were detailed. The patients mailed back their questionnaire.

RESULTS

A total of 124 patients from 12 to 19 years of age were included with a response rate of 82% (all anonymous); 23% of the patients thought that diet was a possible cause of IBD and 22% that one of the targets of their treatment was to cure their disease for good. Of the patients reported having Crohn disease, 46% knew the anoperineal location and 14% knew that Crohn disease can affect the entire digestive tract. Twenty-five percent of the patients were able to name one side effect of azathioprine (88% had already received this treatment), 24% were able to name one side effect of infliximab (54% had already received this treatment), 70% of the adolescents knew that smoking worsens Crohn disease, 68% declared they had learned about their IBD from their pediatrician, and 81% said they would like to receive more information.

CONCLUSION

Adolescents with IBD have gaps in their general knowledge and the different treatments of their disease. Their main source of information is their pediatrician, warranting the implementation of customized patient education sessions.

Evaluation of an image-based tracking workflow with Kalman filtering for automatic image plane alignment in interventional MRI

Recently, a workflow for magnetic resonance (MR) image plane alignment based on tracking in real-time MR images was introduced. The workflow is based on a tracking device composed of 2 resonant micro-coils and a passive marker, and allows for tracking of the passive marker in clinical real-time images and automatic (re-)initialization using the microcoils. As the Kalman filter has proven its benefit as an estimator and predictor, it is well suited for use in tracking applications. In this paper, a Kalman filter is integrated in the previously developed workflow in order to predict position and orientation of the tracking device. Measurement noise covariances of the Kalman filter are dynamically changed in order to take into account that, according to the image plane orientation, only a subset of the 3D pose components is available. The improved tracking performance of the Kalman extended workflow could be quantified in simulation results. Also, a first experiment in the MRI scanner was performed but without quantitative results yet.

[Public health program planning through the capabilities lens]

As a theory of distributive justice, Amartya Sen's theory of capabilities questions the choices and decisions associated with the development and planning of public health programs. In this paper, the authors describe Sen's approach and explore its implications for public health by applying it to the case of tobacco control programs. Based on the tobacco control objectives set by the WHO and on the MPOWER package of measures, they notice that the translation of the objectives in capabilities call for a greater attention to the conditions of living of the different population groups. It also put into doubt the measures restricting access to tobacco products that do not account for their differing impacts on adults. The authors conclude that this ethical perspective is likely to be controversial as it may rank freedom as a value that overrides health.

Towards a Hall effect magnetic tracking device for MRI

This paper presents the first prototype of a magnetic tracking device for Magnetic Resonance Imaging. The unique relationship between the space coordinates of a MRI scanner bore and the magnetic field gradients used in MRI allows building a localization system based on an accurate measurement of these gradients. These gradients are measured thanks to a 3D Hall device with a footprint of only 50µm(2), integrated with its specific conditioning circuit in a low cost, low voltage 0.35µm CMOS process. The first experimental results show that a sub-millimeter localization is possible. It opens the way to the development of MRI compatible magnetic tracking systems integrable in a surgical tool.

Evaluation of an image-based tracking workflow using a passive marker and resonant micro-coil fiducials for automatic image plane alignment in interventional MRI

In this paper, an original workflow is presented for MR image plane alignment based on tracking in real-time MR images. A test device consisting of two resonant micro-coils and a passive marker is proposed for detection using image-based algorithms. Micro-coils allow for automated initialization of the object detection in dedicated low flip angle projection images; then the passive marker is tracked in clinical real-time MR images, with alternation between two oblique orthogonal image planes along the test device axis; in case the passive marker is lost in real-time images, the workflow is reinitialized. The proposed workflow was designed to minimize dedicated acquisition time to a single dedicated acquisition in the ideal case (no reinitialization required). First experiments have shown promising results for test-device tracking precision, with a mean position error of 0.79 mm and a mean orientation error of 0.24°.

Spironolactone-related inhibitors of type II 17beta-hydroxysteroid dehydrogenase: chemical synthesis, receptor binding affinities, and proliferative/antiproliferative activities

The family of 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) catalyzes the formation and inactivation of testosterone (T), dihydrotestosterone (DHT), and estradiol (E2), thus playing a crucial role in the regulation of active steroid hormones in target tissues. Among the five known 17beta-HSD enzymes, type II catalyzes the oxidation of E2 into estrone (E1), T into androstenedione, DHT into androstanedione, and 20alpha-dihydroprogesterone into progesterone. Specific inhibitors are thus an interesting means to study the regulation and to probe the structure of type II 17beta-HSD. In this context, we have efficiently synthesized a series of 7alpha-thioalkyl and 7alpha-thioaryl derivatives of spironolactone that inhibit type II 17beta-HSD. These new C19-steroidal inhibitors possess two important pharmacophores, namely 17-spiro-gamma-lactone and a bulky side-chain at the 7alpha-position. It was found that a para-substituted benzylthio group at the 7alpha-position enhances the inhibitory potency of spironolactone derivatives on type II 17beta-HSD. In fact, the compound with a para-hydroxy-benzylthio group showed an IC50 value of 0.5 microM against type II 17beta-HSD, whereas the compound with a para-[2-(1-piperidinyl)-ethoxy]-benzylthio group inhibited this enzyme with an IC50 value of 0.7 microM. The latter inhibitor is more selective than the former because it did not show any inhibitory potency against P450 aromatase as well as any affinity towards four steroid receptors (AR, PR, GR, ER). As a result, this inhibitor did not show any proliferative effect on androgen-sensitive Shionogi cells and estrogen-sensitive ZR-75-1 cells. These findings contribute to a better knowledge of the structure of type II 17beta-HSD and offer an interesting tool to study the regulation of this enzyme in several biological systems.

Contractile effects of vanadate on aorta rings from virgin and pregnant rats

The present study was undertaken to characterize the contractile effects of vanadate on thoracic aorta rings from virgin and term-pregnant rats. Vanadate caused concentration-dependent contraction in rat aortic rings with an EC50 (concentration producing 50% maximum response) of 0.10 mM. Contractions in response to vanadate were equivalent to the ones measured with 1 microM phenylephrine. The effects of vanadate were not affected by indomethacin (up to 10 microM), an inhibitor of prostanoid cyclooxygenase, but were blocked in a concentration-dependent manner by staurosporine (0.1-1.0 microM), an inhibitor of protein kinase C. Vanadate exhibited a significant decrease of contractile responses in aorta of pregnant as compared to virgin rats. When aortic rings were bathed in presence of different concentrations of vanadate, the concentration-response curve to phenylephrine was shifted to the left, but maximum response was not affected. The potentiation of the contractions to phenylephrine by vanadate was significantly more prominent in aorta of virgin than of pregnant rats. These results suggest that the contractile effect of vanadate on rat aorta is independent of endogenous prostanoids and may be mediated by protein kinase C-dependent pathway. These results also show that the contractile response to vanadate on the rat aorta is impaired during pregnancy.

Quantitative assessment of average velocity in inferior vena cava by phase-display MR imaging: pulsed Doppler correlation

A technique for measuring average velocity in the inferior vena cava (IVC) by using phase-display magnetic resonance (MR) imaging is described. Fifteen healthy subjects were imaged, and the velocities and spectra obtained by MR were compared with pulsed Doppler results. Distortions of the "zebra-striped" images obtained along the axis of the vessel were measured at the same level of the IVC as in pulsed Doppler. Measurements of average velocities in the IVC made by the two methods were very similar, and velocity curves obtained during the cardiac cycle were superimposable. Phase-display MR imaging has the potential to noninvasively assess blood flow in large vessels as accurately as pulsed Doppler.

Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging

Intravoxel incoherent motion (IVIM) imaging is a method the authors developed to visualize microscopic motions of water. In biologic tissues, these motions include molecular diffusion and microcirculation of blood in the capillary network. IVIM images are quantified by an apparent diffusion coefficient (ADC), which integrates the effects of both diffusion and perfusion. The aim of this work was to demonstrate how much perfusion contributes to the ADC and to present a method for obtaining separate images of diffusion and perfusion. Images were obtained at 0.5 T with high-resolution multisection sequences and without the use of contrast material. Results in a phantom made of resin microspheres demonstrated the ability of the method to separately evaluate diffusion and perfusion. The method was then applied in patients with brain and bone tumors and brain ischemia. Clinical results showed significant promise of the method for tissue characterization by perfusion patterns and for functional studies in the evaluation of the microcirculation in physiologic and pathologic conditions, as, for instance, in brain ischemia.

MR imaging of intravoxel incoherent motions: application to diffusion and perfusion in neurologic disorders

Molecular diffusion and microcirculation in the capillary network result in a distribution of phases in a single voxel in the presence of magnetic field gradients. This distribution produces a spin-echo attenuation. The authors have developed a magnetic resonance (MR) method to image such intravoxel incoherent motions (IVIMs) by using appropriate gradient pulses. Images were generated at 0.5 T in a high-resolution, multisection mode. Diffusion coefficients measured on images of water and acetone phantoms were consistent with published values. Images obtained in the neurologic area from healthy subjects and patients were analyzed in terms of an apparent diffusion coefficient (ADC) incorporating the effect of all IVIMs. Differences were found between various normal and pathologic tissues. The ADC of in vivo water differed from the diffusion coefficient of pure water. Results were assessed in relation to water compartmentation in biologic tissues (restricted diffusion) and tissue perfusion. Nonuniform slow flow of cerebrospinal fluid appeared as a useful feature on IVIM images. Observation of these motions may significantly extend the diagnostic capabilities of MR imaging.