Leveraging manifold learning techniques to explore white matter anomalies: An application of the TractLearn pipeline in epilepsy.

An accurate description of brain white matter anatomy in vivo remains a challenge. However, technical progress allows us to analyze structural variations in an increasingly sophisticated way. Current methods of processing diffusion MRI data now make it possible to correct some limiting biases. In addition, the development of statistical learning algorithms offers the opportunity to analyze the data from a new perspective. We applied newly developed tractography models to extract quantitative white matter parameters in a group of patients with chronic temporal lobe epilepsy. Furthermore, we implemented a statistical learning workflow optimized for the MRI diffusion data - the TractLearn pipeline - to model inter-individual variability and predict structural changes in patients. Finally, we interpreted white matter abnormalities in the context of several other parameters reflecting clinical status, as well as neuronal and cognitive functioning for these patients. Overall, we show the relevance of such a diffusion data processing pipeline for the evaluation of clinical populations. The "global to fine scale" funnel statistical approach proposed in this study also contributes to the understanding of neuroplasticity mechanisms involved in refractory epilepsy, thus enriching previous findings.

The use of digital dermoscopy in the surveillance of melanocytic skin lesions: A real-life retrospective study comparing university hospital and private practices.

BACKGROUND: Few studies have evaluated the role of digital dermoscopy (DD) in the surveillance of pigmented lesions in real-life practice. PATIENTS AND METHODS: Patients followed with DD by 4 hospital dermatologists (group 1) and 4 private dermatologists (group 2) were retrospectively included if they had had at least 2 DD examinations for a minimum of 4 pigmented lesions. Their characteristics, risk factors, history of excision of benign nevi and melanomas prior to and during the DD follow-up, and characteristics of detected melanomas, were recorded. RESULTS: One hundred and ninety-six patients were included in group 1 and 205 in groups 2. A family history of melanoma (25% vs. 12%, p<0.01), a personal history of melanoma before DD follow-up (47% vs. 15%, p<0.01), and a family (3% vs. 0%, p=0.01) and personal (8% vs. 1%, p<0.01) germline CDKN2a mutation were more frequent in group 1 than in group 2. In both groups, the number of excisions of benign lesions was higher before DD follow-up (380 and 347, respectively) than during DD follow-up (194 and 132). During follow-up, 29 melanomas were detected in group 1, with a median Breslow thickness of 0.4mm, versus 1.3mm for melanomas diagnosed before DD follow-up (p<0.02). In group 2, 4 melanoma and 5 superficial atypical melanocytic proliferations of unknown significance were detected. The median Breslow thickness of newly diagnosed melanomas was 0.35mm vs. 0.6mm before DD follow-up (p=0.1). CONCLUSION: In both populations in real-life practice, DD seemed to allow the detection of thin melanomas and to decrease the rate of "futile" resections.

Artificial intelligence to predict clinical disability in patients with multiple sclerosis using FLAIR MRI.

PURPOSE: The purpose of this study was to create an algorithm that combines multiple machine-learning techniques to predict the expanded disability status scale (EDSS) score of patients with multiple sclerosis at two years solely based on age, sex and fluid attenuated inversion recovery (FLAIR) MRI data. MATERIALS AND METHODS: Our algorithm combined several complementary predictors: a pure deep learning predictor based on a convolutional neural network (CNN) that learns from the images, as well as classical machine-learning predictors based on random forest regressors and manifold learning trained using the location of lesion load with respect to white matter tracts. The aggregation of the predictors was done through a weighted average taking into account prediction errors for different EDSS ranges. The training dataset consisted of 971 multiple sclerosis patients from the "Observatoire français de la sclérose en plaques" (OFSEP) cohort with initial FLAIR MRI and corresponding EDSS score at two years. A test dataset (475 subjects) was provided without an EDSS score. Ten percent of the training dataset was used for validation. RESULTS: Our algorithm predicted EDSS score in patients with multiple sclerosis and achieved a MSE=2.2 with the validation dataset and a MSE=3 (mean EDSS error=1.7) with the test dataset. CONCLUSION: Our method predicts two-year clinical disability in patients with multiple sclerosis with a mean EDSS score error of 1.7, using FLAIR sequence and basic patient demographics. This supports the use of our model to predict EDSS score progression. These promising results should be further validated on an external validation cohort.

Measurement of the potential geographic accessibility from call to definitive care for patient with acute stroke.

BACKGROUND: The World Health Organization refers to stroke, the second most frequent cause of death in the world, in terms of pandemic. Present treatments are only effective within precise time windows. Only 10% of thrombolysis patients are eligible. Late assessment of the patient resulting from admission and lack of knowledge of the symptoms is the main explanation of lack of eligibility. METHODS: The aim is the measurement of the time of access to treatment facilities for stroke victims, using ambulances (firemen ambulances or EMS ambulances) and private car. The method proposed analyses the potential geographic accessibility of stroke care infrastructure in different scenarios. The study allows better considering of the issues inherent to an area: difficult weather conditions, traffic congestion and failure to respect the distance limits of emergency transport. RESULTS: Depending on the scenario, access times vary considerably within the same commune. For example, between the first and the second scenario for cities in the north of Rhône county, there is a 10 min difference to the nearest Primary Stroke Center (PSC). For the first scenario, 90% of the population is 20 min away of the PSC and 96% for the second scenario. Likewise, depending on the modal vector (fire brigade or emergency medical service), overall accessibility from the emergency call to admission to a Comprehensive Stroke Center (CSC) can vary by as much as 15 min. CONCLUSIONS: The setting up of the various scenarios and modal comparison based on the calculation of overall accessibility makes this a new method for calculating potential access to care facilities. It is important to take into account the specific pathological features and the availability of care facilities for modelling. This method is innovative and recommendable for measuring accessibility in the field of health care. This study makes possible to highlight the patients' extension of care delays. Thus, this can impact the improvement of patient care and rethink the healthcare organization. Stroke is addressed here but it is applicable to other pathologies.

Reliability of White Matter Microstructural Changes in HIV Infection: Meta-Analysis and Confirmation.

BACKGROUND: Diffusion tensor imaging has been widely used to measure HIV effects on white matter microarchitecture. While many authors have reported reduced fractional anisotropy and increased mean diffusivity in HIV, quantitative inconsistencies across studies are numerous. PURPOSE: Our aim was to evaluate the consistency across studies of HIV effects on DTI measures and then examine the DTI reliability in a longitudinal seropositive cohort. DATA SOURCES: Published studies and investigators. STUDY SELECTION: The meta-analysis included 16 cross-sectional studies reporting fractional anisotropy and 12 studies reporting mean diffusivity in the corpus callosum. DATA ANALYSIS: Random-effects meta-analysis was used to estimate study standardized mean differences and heterogeneity. DTI longitudinal reliability was estimated in seropositive participants studied before and 3 and 6 months after beginning treatment. DATA SYNTHESIS: Meta-analysis revealed lower fractional anisotropy (standardized mean difference, -0.43; P < .001) and higher mean diffusivity (standardized mean difference, 0.44; P < .003) in seropositive participants. Nevertheless, between-study heterogeneity accounted for 58% and 66% of the observed variance (P < .01). In contrast, the longitudinal cohort fractional anisotropy was higher and mean diffusivity was lower in seropositive participants (both, P < .001), and fractional anisotropy and mean diffusivity measures were very stable during 6 months, with intraclass correlation coefficients all >0.96. LIMITATIONS: Many studies pooled participants with varying treatments, ages, and disease durations. CONCLUSIONS: HIV effects on WM microstructure had substantial variations that could result from acquisition, processing, or cohort-selection differences. When acquisition parameters and processing were carefully controlled, the resulting DTI measures did not show high temporal variation. HIV effects on WM microstructure may be age-dependent. The high longitudinal reliability of DTI WM microstructure measures makes them promising disease-activity markers.

[The school doctorand suspected child abuse : towards good practice recommendations in the child's interest]. / Le médecin scolaire et la suspicion de maltraitance à enfant : vers des recommandations de bonnes pratiques dans l'intérêt de l'enfant.

Child maltreatment, including all forms of mal¬treatment, remains a major public health problem in high-income countries. Healthcare professionals only contribute to a small proportion of reports. In French-speaking Belgium, almost 100 % of school-aged children are regularly submitted to periodical school health visits. The school health doctor is well placed to recognize neglected or abused children. Based on international good practice recommendations, this paper proposes means for the detection and management of child abuse in the context of school medicine.

La maltraitance infantile représente, dans les pays à haut niveau de revenus, un «problème de santé publique majeur¼, 5 à 10 % des enfants étant concernés, toutes formes de maltraitances confondues. Les professionnels de santé contribuent à une petite proportion seulement des signale¬ments. En Fédération Wallonie-Bruxelles, les bilans de santé scolaire périodiques couvrant près de 100 % des enfants sco¬larisés, le médecin scolaire est bien placé pour le repérage d'enfants exposés à une négligence de soins et/ou à de mauvais traitements. Se basant sur des recommandations de bonne pratique publiées, cet article propose des pistes d'action per¬mettant de contribuer à un meilleur repérage et à une prise en charge adaptée de la maltraitance infantile dans le cadre de la médecine scolaire.

[Early detection to prevent mental illness during adolescence: ethical and theoretical considerations]. / Détection prévenante en santé mentale chez l'adolescent: considérations éthiques et théoriques.

In the face of changes that characterise adolescence, a number of youth experience ill-being, as part of a normal developmental process. For some of them, however, this ill-being may represent early signs of a psychopathological process. Regarding depression and psychosis, such early signs are non-specific, which complicates and delays treatment. In addition, issues such as stigmatization and unfamiliarity with these psychopathologies represent major obstacles to treatment access. Attempts to early detection, which involves identifying risk factors in order to provide support and follow-up, making an effort to take these clinical signs seriously, while at the same time avoiding to mistake a normal developmental process for a pathological condition.

[Vulnerable children detected by the school health service: the forgotten?]. / Enfants en situation de vulnérabilité médico-psycho-sociale repérés par la médecine scolaire: les oubliés du réseau de soins?

The current health needs of children largely exceeds the biomedical model. The school doctor occupies a special position where he can take into account the social determinants of health and identify vulneirable children. After the detection by the school health service, the harmonious development of, the child requires that health professionals cooperate in a "preventive network".

[The "choking game" and asphyxial games: epidemiological and clinical data]. / Le "jeu du foulard" et autres jeux d'asphyxie: données épidémiologiques et cliniques.

Asphyxial games have been played by children and adolescents for generations. What seems to be more recent is an increase in mortality linked to the increasing use of ligatures and "playing" the game alone, as reported by the media. This article summarizes the current epidemiological and clinical data on the subject.

Global Functional Disconnections in Post-anoxic Coma Patient.

Disorders of consciousness have been related to different disconnection patterns as assessed by neuroimaging tools such as PET or fMRI. In this report, we use resting-state functional MRI acquisition and a functional connectivity analysis by graph of brain networks, to investigate the global residual connection pattern in a patient with consciousness disorders following post-anoxic injury. We then compare this pattern with those of a group of twenty controls. We observed that the patient's graph presents multiple disconnections in primary areas and in high-order associative areas. This pattern is consistent with a vegetative state, as reported by other groups. Further, the informations conveyed by this approach are consistent with those provided by PET, fMRI and EP. This new approach presents a very strong potential for diagnosis for consciousness disorder patients since it is applicable very early after the insult.

Decline in breast cancer incidence in the Flemish region of Belgium after a decline in hormonal replacement therapy.

BACKGROUND: Breast cancer incidence rate in Belgian women was as high as 152.7 for 100 000 in 2003 (adjusted on European population). We made an estimation of the contribution of hormone replacement therapy (HRT) on breast cancer incidence from 1999 to 2005 in women aged 50-69 years in Flanders. METHODS: Breast cancer data were extracted from the Belgium Cancer Registry. Drug consumption was computed from drug sales data. The fraction of breast cancers attributable to HRT was calculated by year, using the relative risks of the Million Women Study in the UK. RESULTS: The proportion of women aged 50-69 years using HRT in Flanders increased since 1992, peaked at 20% in 2001, then decreased to 8% in 2008. The incidence of breast cancer in 100 000 women aged 50-69 years in Flanders increased from 332.8 in 1999 to 407.9 in 2003, then decreased to 366.1 in 2005; the variations were mostly noticeable for tumors <20 mm in size. The fraction of breast cancers attributed to HRT peaked at 11% in 2001 and decreased afterward. CONCLUSION: The high level of breast cancer observed in the years 2001-2003 in Flanders can be partly attributed to the use of HRT. Since participation to mammography screening of Flemish women aged 50-69 years was still on the rise in 2003 and never exceeds 62%, the decrease in breast cancer incidence was likely to be due to the decrease in HRT use and not to screening saturation.

Removal of oxyanions from synthetic wastewater via carbonation process of calcium hydroxide: applied and fundamental aspects.

Removal of oxyanions (selenite, selenate, arsenate, phosphate and nitrate) during calcite formation was experimentally studied using aqueous carbonation of calcium hydroxide under moderate pressure (P(CO2) congruent with 20 bar) and temperature (30 degrees C). The effects of Ca(OH)(2) dose (10 and 20 g), Ca(OH)(2) source (commercial pure material or alkaline paper mill waste) and oxyanion initial concentration (from 0 to 70 mg atom/L) were investigated for this anisobaric gas-liquid-solid system. The Ca(OH)(2) carbonation reaction allowed successfully the removal of selenite (>90%), arsenate (>78%) and phosphate (congruent with 100%) from synthetic solutions. Conversely, nitrate and selenate had not any physicochemical affinity/effect during calcite formation. The rate of CO(2) transfer during calcite formation in presence of oxyanions was equal or slower than for an oxyanion-free system, allowing to define a retarding kinetic factor RF that can vary between 0 (no retarding effect) to 1 (total inhibition). For selenite and phosphate RF was quite high, close to 0.3. A small retarding effect was detected for arsenate (RF approximately 0.05) and no retarding effect was detected for selenate and nitrate (RF approximately 0). In general, RF depends on the oxyanion initial concentration, oxyanion nature and Ca(OH)(2) dose. The presence of oxyanions could also influence the crystal morphology and aggregation/agglomeration process. For example, a c-axis elongation of calcite crystals was clearly observed at the equilibrium, for calcite formation in presence of selenite and phosphate. The oxyanions removal process proposed herein was inspired on the common physicochemical treatment of wastewater using calcium hydroxide (Ca(OH)(2)). The particularity, for this novel method is the simultaneous calcium hydroxide carbonation with compressed carbon dioxide in order to stabilise the solid matter. This economical and ecological method could allow the removal of various oxyanions as well as the ex situ mineral sequestration of CO(2); particularly, when the Ca(OH)(2) source comes from alkaline solid waste.

Mineral sequestration of CO(2) by aqueous carbonation of coal combustion fly-ash.

The increasing CO(2) concentration in the Earth's atmosphere, mainly caused by fossil fuel combustion, has led to concerns about global warming. A technology that could possibly contribute to reducing carbon dioxide emissions is the in-situ mineral sequestration (long term geological storage) or the ex-situ mineral sequestration (controlled industrial reactors) of CO(2). In the present study, we propose to use coal combustion fly-ash, an industrial waste that contains about 4.1 wt.% of lime (CaO), to sequester carbon dioxide by aqueous carbonation. The carbonation reaction was carried out in two successive chemical reactions, first, the irreversible hydration of lime. second, the spontaneous carbonation of calcium hydroxide suspension. A significant CaO-CaCO(3) chemical transformation (approximately 82% of carbonation efficiency) was estimated by pressure-mass balance after 2h of reaction at 30 degrees C. In addition, the qualitative comparison of X-ray diffraction spectra for reactants and products revealed a complete CaO-CaCO(3) conversion. The carbonation efficiency of CaO was independent on the initial pressure of CO(2) (10, 20, 30 and 40 bar) and it was not significantly affected by reaction temperature (room temperature "20-25", 30 and 60 degrees C) and by fly-ash dose (50, 100, 150 g). The kinetic data demonstrated that the initial rate of CO(2) transfer was enhanced by carbonation process for our experiments. The precipitate calcium carbonate was characterized by isolated micrometric particles and micrometric agglomerates of calcite (SEM observations). Finally, the geochemical modelling using PHREEQC software indicated that the final solutions (i.e. after reaction) are supersaturated with respect to calcium carbonate (0.7 < or = saturation index < or = 1.1). This experimental study demonstrates that 1 ton of fly-ash could sequester up to 26 kg of CO(2), i.e. 38.18 ton of fly-ash per ton of CO(2) sequestered. This confirms the possibility to use this alkaline residue for CO(2) mitigation.

Stress-driven phase transformation and the roughening of solid-solid interfaces.

The application of stress to multiphase solid-liquid systems often results in morphological instabilities. Here we propose a solid-solid phase transformation model for roughening instability in the interface between two porous materials with different porosities under normal compression stresses. This instability is triggered by a finite jump in the free energy density across the interface, and it leads to the formation of fingerlike structures aligned with the principal direction of compaction. The model is proposed as an explanation for the roughening of stylolites-irregular interfaces associated with the compaction of sedimentary rocks that fluctuate about a plane perpendicular to the principal direction of compaction.

[First-generation immigrant adolescents' physical and mental health and behaviors]. / La santé physique, mentale et les comportements de santé des adolescents immigrants de première génération.

The objectives of this article are to: a) review literature about physical, mental health and behaviors of first generation immigrant adolescents and its evolution; b) compare first and second generations immigrant adolescents'health. Studies usually compare first generation and others adolescents groups: 1) first generation adolescents shows better physical health and behaviors than second generation; 2) first generation adolescents shows variable results for mental health compared to second generation and host adolescents according to the studies; 3) a degradation of physical health and behaviors is observed with the time passed in the host country. These results show necessity of a precocious evaluation of first generation adolescents' needs for a good planification of health promotion and prevention actions to preserve their health advantage at arrival.

[The Cancer Registry of the Jules Bordet Institute, a new tool for the institution and its researchers. Description of cases incident in 2000-2001]. / Le Registre du Cancer de l'Institut Bordet, un nouvel outil à la disposition de l'institution et de ses chercheurs. Présentation des cas d'incidence en 2000 et 2001.

A hospital Cancer Registry has recently been initiated at the Jules Bordet Institute. The collected information allows to report pathology items such as incidence date, site, morphology and stage. It permits to describe the therapeutic choices, which, broken down by organ and stage, can be compared to guidelines in a process assessment. The objectives of this registry are institutional (statistical and organisational finalities as well as quality control ones), extra-institutional (participation to the public network of cancer registration), and scientific (providing the researchers a common database that can be queried using multiple criteria to be completed by further detailed data). This paper reports on 3,587 incident cancer cases in 2000 and 2001 which were managed at the Jules Bordet Institute for the primary episode. Cancers in women represent 64.3% of all records, for only 35.7% of men, while in the Belgian National Cancer Registry, the proportion is reversed to 46.7% of women and 53.3% of men. The distribution of cancer by site is also quite different in our hospital registry where breast cancer in women, melanoma in both sexes, lung cancer and head and neck cancers in men are over-represented compared to the general population, while colorectal cancer is underrepresented in both sexes.

[Newly immigrant adolescents health and quality of life in Belgium: screening and prevention in school medicine]. / Santé et qualité de vie des adolescents récemment immigrés en Belgique: dépistage et prévention en médecine scolaire.

OBJECTIVES: Little is known so far about the health of newly immigrant adolescents. The present study aimed to evaluate their health and quality of life (QoL) and to reinforce prevention and health promotion in school medicine. METHODS: One hundred and fifty-eight adolescents (mean age: 15,4 years) from 37 nationalities were included in the study in two health centers in Brussels. This study was carried out by medical records analysis and administration of a questionnaire about health and QoL (VSP-A) in several languages. RESULTS: The results showed adolescents in good physical health. Nevertheless their quality of life deteriorated over time in Belgium. The QoL was significantly lower for adolescents without social support: 48,0 (SD=13,5) vs 60,6 (SD=11,1) compared with adolescents with social support - i.e. with one resource person - on a scale from 0 to 100. Adolescents had many subjective health problems, like "the future" cited by half of them. CONCLUSION: This study shows the importance of developping a specific approach to newly immigrant adolescents health and the contribution of school medicine in the identification of biological, psychological and social needs and hightlights the preventive answers carried out by school medicine.

Helicity conservation in gauge boson scattering at high energy.

We remark that the high energy gauge boson scattering processes involving two-body initial and final states satisfy certain selection rules described as helicity conservation of the gauge boson amplitudes (GBHC). These rules are valid at the Born level, as well as at the level of the leading and subleading 1-loop logarithmic corrections, in both the standard model and the minimal supersymmetric standard model (MSSM). A "fermionic equivalence" theorem is also proved, which suggests that GBHC is valid at all orders in the MSSM at sufficiently high energies, where the mass suppressed contributions are neglected.

Primary stenting for the acute treatment of carotid artery dissection.

OBJECTIVES: To review and evaluate our experience with carotid artery stenting in the acute treatment of carotid artery dissection (CAD). PATIENTS AND METHODS: Reviewing the charts of our hospital between 2000 and 2001, we found two consecutive patients who benefited from primary stenting for the acute treatment of spontaneous extracranial internal CAD. RESULTS: Primary stenting of the internal carotid artery was successful in both cases without any post-operative complications. Clinical and US duplex scan follow-up confirmed the absence of neurological symptoms and the patency of the internal carotid artery with complete disappearance of the dissection at 36 and 42 months after the procedure, respectively. CONCLUSION: Despite the small number of patients, primary stenting for acute CAD seems to be safe and effective.