Characterization of spatio-temporal dynamics of the constrained network of the filamentous fungus Podospora anserina using a geomatics-based approach

In their natural environment, fungi are subjected to a wide variety of environmental stresses which they must cope with by constantly adapting the architecture of their growing network. In this work, our objective was to finely characterize the thallus development of the filamentous fungus Podospora anserina subjected to different constraints that are simple to implement in vitro and that can be considered as relevant environmental stresses, such as a nutrient-poor environment or non-optimal temperatures. At the Petri dish scale, the observations showed that the fungal thallus is differentially affected (thallus diameter, mycelium aspect) according to the stresses but these observations remain qualitative. At the hyphal scale, we showed that the extraction of the usual quantities (i.e. apex, node, length) does not allow to distinguish the different thallus under stress, these quantities being globally affected by the application of a stress in comparison with a thallus having grown under optimal conditions. Thanks to an original geomatics-based approach based on the use of automatized Geographic Information System (GIS) tools, we were able to produce maps and metrics characterizing the growth dynamics of the networks and then to highlight some very different dynamics of network densification according to the applied stresses. The fungal thallus is then considered as a map and we are no longer interested in the quantity of material (hyphae) produced but in the empty spaces between the hyphae, the intra-thallus surfaces. This study contributes to a better understanding of how filamentous fungi adapt the growth and densification of their network to potentially adverse environmental changes.

Genome-scale phylogeny and comparative genomics of the fungal order Sordariales

The order Sordariales is taxonomically diverse, and harbours many species with different lifestyles and large economic importance. Despite its importance, a robust genome-scale phylogeny, and associated comparative genomic analysis of the order is lacking. In this study, we examined whole-genome data from 99 Sordariales, including 52 newly sequenced genomes, and seven outgroup taxa. We inferred a comprehensive phylogeny that resolved several contentious relationships amongst families in the order, and cleared-up intrafamily relationships within the Podosporaceae. Extensive comparative genomics showed that genomes from the three largest families in the dataset (Chaetomiaceae, Podosporaceae and Sordariaceae) differ greatly in GC content, genome size, gene number, repeat percentage, evolutionary rate, and genome content affected by repeat-induced point mutations (RIP). All genomic traits showed phylogenetic signal, and ancestral state reconstruction revealed that the variation of the properties stems primarily from within-family evolution. Together, the results provide a thorough framework for understanding genome evolution in this important group of fungi.

Prediction and experimental evidence of different growth phases of the Podospora anserina hyphal network

Under ideal conditions, the growth of the mycelial network of a filamentous fungus is monotonous, showing an ever increasing complexity with time. The components of the network growth are very simple and based on two mechanisms: the elongation of each hypha, and their multiplication by successive branching. These two mechanisms are sufficient to produce a complex network, and could be localized only at the tips of hyphae. However, branching can be of two types, apical or lateral, depending on its location on the hyphae, therefore imposing the redistribution of the necessary material in the whole mycelium. From an evolutionary point of view, maintaining different branching processes, with additional energy needs for structure and metabolism, is intriguing. We propose in this work to discuss the advantages of each branching type using a new observable for the network growth, allowing us to compare growth configurations. For this purpose, we build on experimental observations of the Podospora anserina mycelium growth, enabling us to feed and constrain a lattice-free modeling of this network based on a binary tree. First, we report the set of statistics related to the branches of P. anserina that we have implemented into the model. Then, we build the density observable, allowing us to discuss the succession of growth phases. We predict that density over time is not monotonic, but shows a decay growth phase, clearly separated from an other one by a stationary phase. The time of appearance of this stable region appears to be driven solely by the growth rate. Finally, we show that density is an appropriate observable to differentiate growth stress.

GUN Mutants: New Weapons To Unravel Ascospore Germination Regulation in the Model Fungus Podospora anserina

In Podospora anserina as in many other Ascomycetes, ascospore germination is a regulated process that requires the breaking of dormancy. Despite its importance in survival and dispersal, ascospore germination in filamentous fungi has been poorly investigated, and little is known about its regulation and genetic control. We have designed a positive genetic screen that led to the isolation of mutants showing uncontrolled germination, the GUN (Germination UNcontrolled) mutants. Here, we report on the characterization of the gun1SG (Spontaneous Germination) mutant. We show that gun1SG is mutated in Pa_6_1340, the ortholog of Magnaporthe oryzae Pth2, which encodes a carnitine-acetyltransferase (CAT) involved in the shuttling of acetyl coenzyme A between peroxisomes and mitochondria and which is required for appressorium development. Bioinformatic analysis revealed that the mutated residue (I441) is highly conserved among Fungi and that the mutation has a deleterious impact on the protein function. We show that GUN1 is essential for ascospore germination and that the protein is localized both in mitochondria and in peroxisomes. Finally, epistasis studies allowed us to place GUN1 together with the PaMpk2 MAPK pathway upstream of the PaNox2/PaPls1 complex in the regulation of ascospore germination. In addition, we show that GUN1 plays a role in appressorium functioning. The pivotal role of GUN1, the ortholog of Pth2, in ascospore germination and in appressorium functioning reinforces the idea of a common genetic regulation governing both appressorium development and melanized ascospore germination. Furthermore, we characterize the second CAT encoded in P. anserina genome, Pa_3_7660/GUP1, and we show that the function of both CATs is conserved in P. anserina. IMPORTANCE The regulation of ascospore germination in filamentous fungi has been poorly investigated so far. To unravel new genes involved in this regulation pathway, we conducted a genetic screen in Podospora anserina, and we isolated 57 mutants affected in ascospore germination. Here, we describe the Germination UNcontrolled One (gun1SG) mutant, and we characterize the gene affected. GUN1 is a peroxisomal/mitochondrial carnitine-acetyltransferase required for acetyl coenzyme A shuttling between both organelles, and we show that GUN1 is a pleiotropic gene also involved in appressorium functioning similarly to its ortholog, the pathogenesis factor Pth2, in the plant pathogen Magnaporthe oryzae. Given the similarities in the regulation of appressorium development and ascospore germination, we speculate that discovering new genes controlling ascospore germination in P. anserina may lead to the discovery of new pathogenesis factors in pathogenic fungi. The characterization of GUN1, the ortholog of M. oryzae Pth2, represents a proof of concept.

Stepwise recombination suppression around the mating-type locus in an ascomycete fungus with self-fertile spores

Recombination is often suppressed at sex-determining loci in plants and animals, and at self-incompatibility or mating-type loci in plants and fungi. In fungal ascomycetes, recombination suppression around the mating-type locus is associated with pseudo-homothallism, i.e. the production of self-fertile dikaryotic sexual spores carrying the two opposite mating types. This has been well studied in two species complexes from different families of Sordariales: Podospora anserina and Neurospora tetrasperma. However, it is unclear whether this intriguing association holds in other species. We show here that Schizothecium tetrasporum, a fungus from a third family in the order Sordariales, also produces mostly self-fertile dikaryotic spores carrying the two opposite mating types. This was due to a high frequency of second meiotic division segregation at the mating-type locus, indicating the occurrence of a single and systematic crossing-over event between the mating-type locus and the centromere, as in P. anserina. The mating-type locus has the typical Sordariales organization, plus a MAT1-1-1 pseudogene in the MAT1-2 haplotype. High-quality genome assemblies of opposite mating types and segregation analyses revealed a suppression of recombination in a region of 1.47 Mb around the mating-type locus. We detected three evolutionary strata, indicating a stepwise extension of recombination suppression. The three strata displayed no rearrangement or transposable element accumulation but gene losses and gene disruptions were present, and precisely at the strata margins. Our findings indicate a convergent evolution of self-fertile dikaryotic sexual spores across multiple ascomycete fungi. The particular pattern of meiotic segregation at the mating-type locus was associated with recombination suppression around this locus, that had extended stepwise. This association between pseudo-homothallism and recombination suppression across lineages and the presence of gene disruption at the strata limits are consistent with a recently proposed mechanism of sheltering deleterious alleles to explain stepwise recombination suppression.

Prediction and experimental evidence of the optimisation of the angular branching process in the thallus growth of Podospora anserina

Based upon apical growth and hyphal branching, the two main processes that drive the growth pattern of a fungal network, we propose here a two-dimensions simulation based on a binary-tree modelling allowing us to extract the main characteristics of a generic thallus growth. In particular, we showed that, in a homogeneous environment, the fungal growth can be optimized for exploration and exploitation of its surroundings with a specific angular distribution of apical branching. Two complementary methods of extracting angle values have been used to confront the result of the simulation with experimental data obtained from the thallus growth of the saprophytic filamentous fungus Podospora anserina. Finally, we propose here a validated model that, while being computationally low-cost, is powerful enough to test quickly multiple conditions and constraints. It will allow in future works to deepen the characterization of the growth dynamic of fungal network, in addition to laboratory experiments, that could be sometimes expensive, tedious or of limited scope.

Is the Severity of the Clinical Expression of Anorexia Nervosa Influenced by an Anxiety, Depressive, or Obsessive-Compulsive Comorbidity Over a Lifetime?

Purpose: The relationship between anxiety or depressive comorbidities, their chronology of onset, and the severity of anorexia nervosa (AN) is not well-studied. We hypothesize that the existence of a comorbidity, particularly before the onset of AN, is associated with greater severity of AN. Methods: One hundred seventy-seven subjects were assessed. The prevalence of major depressive disorder (MDD), obsessive-compulsive disorder (OCD), generalized anxiety disorder (GAD), and social phobia (SP) as well as their chronology of onset were studied. The assessment criteria of AN severity were the overall clinical condition, body mass index (BMI) on admission, lowest BMI, intensity of the eating symptoms, age at the onset of AN, illness duration, number of hospitalizations, and quality of life. Results: Patients with AN had the greatest clinical severity when they had a comorbid disorder over their lifetime, such as MDD, GAD, or SP. These comorbidities along with OCD were associated with a higher level of eating symptoms and a more altered quality of life. A profile of maximum severity was associated with a higher prevalence of MDD and GAD. Concerning the chronology of onset, the age at the start of AN was later in cases of MDD or GAD prior to AN. Conclusion: There seems to be an association between severity of AN and both MDD and GAD. The chronology of onset of the comorbidity did not seem to be associated with the severity.

Lignin Degradation and Its Use in Signaling Development by the Coprophilous Ascomycete Podospora anserina

The filamentous fungus Podospora anserina is a good model to study the breakdown of lignocellulose, owing to its ease of culture and genetical analysis. Here, we show that the fungus is able to use a wide range of lignocellulosic materials as food sources. Using color assays, spectroscopy and pyrolysis-gas chromatography mass spectrometry, we confirm that this ascomycete is able to degrade lignin, primarily by hydrolyzing β-O-4 linkages, which facilitates its nutrient uptake. We show that the limited weight loss that is promoted when attacking Miscanthus giganteus is due to a developmental blockage rather than an inefficiency of its enzymes. Finally, we show that lignin, and, more generally, phenolics, including degradation products of lignin, greatly stimulate the growth and fertility of the fungus in liquid cultures. Analyses of the CATΔΔΔΔΔ mutant lacking all its catalases, pro-oxidants and antioxidants indicate that improved growth and fertility of the fungus is likely caused by augmented reactive oxygen species levels triggered by the presence of phenolics.

Cannabis-Associated Psychotic-like Experiences Are Mediated by Developmental Changes in the Parahippocampal Gyrus

OBJECTIVE

Cannabis consumption during adolescence has been reported as a risk factor for psychotic-like experiences (PLEs) and schizophrenia. However, brain developmental processes associated with cannabis-related PLEs are still poorly described.

METHOD

A total of 706 adolescents from the general population who were recruited by the IMAGEN consortium had structural magnetic resonance imaging scans at both 14 and 19 years of age. We used deformation-based morphometry to map voxelwise brain changes between the two time points, using the pairwise algorithm in SPM12b. We used an a priori region-of-interest approach focusing on the hippocampus/parahippocampus to perform voxelwise linear regressions. Lifetime cannabis consumption was assessed using the European School Survey Project on Alcohol and other Drugs (ESPAD), and PLEs were assessed with the Comprehensive Assessment Psychotic-like experiences (CAPE) tool. We first tested whether hippocampus/parahippocampus development was associated with PLEs. Then we formulated and tested an a priori simple mediation model in which uncus development mediates the association between lifetime cannabis consumption and PLEs.

RESULTS

We found that PLEs were associated with reduced expansion within a specific region of the right hippocampus/parahippocampus formation, the uncus (p = .002 at the cluster level, p = .018 at the peak level). The partial simple mediation model revealed a significant total effect from lifetime cannabis consumption to PLEs (b = 0.069, 95% CI = 0.04-0.1, p =2 × 10^-16), as well as a small yet significant, indirect effect of right uncus development (0.004; 95% CI = 0.0004-0.01, p = .026).

CONCLUSION

We show here that the uncus development is involved in the cerebral basis of PLEs in a population-based sample of healthy adolescents.

Neural Correlates of Failed Inhibitory Control as an Early Marker of Disordered Eating in Adolescents

BACKGROUND

Binge eating and other forms of disordered eating behavior (DEB) are associated with failed inhibitory control. This study investigated the neural correlates of failed inhibitory control as a potential biomarker for DEB.

METHODS

The study used prospective longitudinal data from the European IMAGEN study adolescent cohort. Participants completed baseline assessments (questionnaires and a brain scan [functional magnetic resonance imaging]) at 14 years of age and a follow-up assessment (questionnaires) at 16 years of age. Self-reported binge eating and/or purging were used to indicate presence of DEB. Neural correlates of failed inhibition were assessed using the stop signal task. Participants were categorized as healthy control subjects (reported no DEB at both time points), maintainers (reported DEB at both time points), recoverers (reported DEB at baseline only), and developers (reported DEB at follow-up only). Forty-three individuals per group with complete scanning data were matched on gender, age, puberty, and intelligence (N = 172).

RESULTS

At baseline, despite similar task performance, incorrectly responding to stop signals (failed inhibitory control) was associated with greater recruitment of the medial prefrontal cortex and anterior cingulate cortex in the developers compared with healthy control subjects and recoverers.

CONCLUSIONS

Greater recruitment of the medial prefrontal and anterior cingulate regions during failed inhibition accords with abnormal evaluation of errors contributing to DEB development. As this precedes symptom onset and is evident despite normal task performance, neural responses during failed inhibition may be a useful biomarker of vulnerability for DEB. This study highlights the potential value of prospective neuroimaging studies for identifying markers of illness before the emergence of behavior changes.

Patients' high acceptability of a future therapeutic HIV vaccine in France: a French paradox?

Background

France is the European country with the lowest level of confidence in vaccines. Measurement of patients’ acceptability towards a future therapeutic HIV vaccine is critically important. Thus, the aim of this study was to evaluate patients’ acceptability of a future therapeutic HIV vaccine in a representative cohort of French patients living with HIV-AIDS (PLWHs).

Methods

This multicentre study used quantitative and qualitative methods to assess PLWHs’ opinions and their potential acceptance of a future therapeutic HIV vaccine. Cross-sectional study on 220 HIV-1 infected outpatients, aged 18–75 years.

Results

The participants’ characteristics were similar to those of the overall French PLWH population. Responses from the questionnaires showed high indices of acceptance: the mean score for acceptability on the Visual Analog Scale VAS was 8.4 of 10, and 92% of patients agreed to be vaccinated if a therapeutic vaccine became available. Acceptability depended on the expected characteristics of the vaccine, notably the duration of its effectiveness: 44% of participants expected it to be effective for life. This acceptance was not associated with socio-demographic, clinical (mode of contamination, duration of disease), quality of life, or illness-perception parameters. Acceptability was also strongly correlated with confidence in the treating physician.

Conclusion

The PLWHs within our cohort had high indices of acceptance to a future therapeutic HIV vaccine.

Trial registration

This study was retroactively registered on ClinicalTrials.gov with ID: NCT02077101 in February 21, 2014.

High-intensity exercise is associated with a better nutritional status in anorexia nervosa

OBJECTIVE

Our aim is to investigate the links between duration and intensity of exercise and the nutritional status in terms of body composition in acute anorexia nervosa (AN) patients.

METHOD

One hundred ninety-one hospitalized women suffering from AN were included. Exercise duration and intensity were assessed using a semistructured questionnaire. Body composition was measured using bioelectrical impedance. Linear multiple regression analyses were carried out using body mass index, fat-free mass index, and fat mass index as dependent variables and including systematically exercise duration, exercise intensity, and other confounding variables described in the literature that were significantly associated with each dependent variable in univariate analysis.

RESULTS

A lower BMI was linked to lower exercise intensity, AN restrictive type, and presence of amenorrhea. A lower FFMI was linked to lower exercise intensity, older age, AN restrictive type, and premenarchal AN. Duration of exercise was not linked to the nutritional status.

CONCLUSIONS

Exercising at higher intensity in AN is associated with a better nutritional status, thus, a better resistance to starvation. The impact of therapeutic physical activity sessions, adapted in terms of exercise intensity and patient's clinical status, should be evaluated during nutrition rehabilitation.

Real-life experience of quality of life, treatment satisfaction, and adherence in patients receiving oral anticoagulants for atrial fibrillation

INTRODUCTION

Direct oral anticoagulants (DOACs) have shown noninferiority to vitamin K antagonists (VKA) in stroke prevention in patients with atrial fibrillation. DOAC treatment may be less demanding than VKA, improving quality of life. To date, there have been no studies of the real-life experience of outpatients receiving anticoagulation therapy for atrial fibrillation in France.

METHODS

An observational descriptive real-life epidemiological study used three validated questionnaires (EQ-5D, PACT-Q2, and MMAS-8 French Translation) to assess quality of life, treatment satisfaction, and adherence, respectively, in 200 patients managed on an outpatient basis for atrial fibrillation who were receiving anticoagulation therapy by VKA or DOAC for at least 3 months. Patients were distributed between four groups: primary VKA (P-VKA), switch from VKA to DOAC (S-DOAC), primary DOAC (P-DOAC), and switch from DOAC to VKA (S-VKA).

RESULTS

Two hundred patients responded to the questionnaires: 89, 50, 52, and 9 in the P-VKA, S-DOAC, P-DOAC and S-VKA groups, respectively. Only the first three groups were compared statistically, because of the small size of the S-VKA group. Quality of life and satisfaction were good in all three groups, with no significant difference in quality of life but significantly greater satisfaction with respect to the "convenience" and "satisfaction" dimensions for DOACs (S-DOAC and P-DOAC groups versus P-VKA group; p<0.001, for both dimensions). Adherence did not significantly differ between groups.

CONCLUSION

The experience of patients under oral anticoagulation therapy for atrial fibrillation managed on an outpatient basis was good, with comparable quality of life under DOACs and VKA, and significantly greater satisfaction under DOACs, without impact on adherence. Taking account of patient preference in "shared decision-making" for the choice of type of anticoagulant could improve the patients' experience of treatment.

Assessment of Health-Related Quality of Life among People Living with HIV in Xinjiang, West China

In total, 679 HIV-positive patients from 4 clinics in Urumqi city were given structured questionnaires by the doctors or nurses treating them. Health-related quality of life (HRQL) was assessed using the Chinese Patient-Reported Outcome Quality of Life-HIV questionnaire versions in Mandarin and Uyghur. This tool has been used in other parts of China and several countries. Compared to France, Australia, United States, Brazil, Thailand, Cambodia, Senegal, and Central-Southern China (CS China), the HRQL was significantly lower among HIV-positive patients in Xinjiang, with regard to the dimension of treatment impact and general health score. The health concern was similar to Brazil and Cambodia but lower than other countries and CS China. Our findings showed high stigmatization: 86% of the patients were afraid to tell others they were HIV positive and 69% often felt or always felt depressed. Only 1% of the patients were on antidepressant treatment.

Barriers to publishing in biomedical journals perceived by a sample of French researchers: results of the DIAzePAM study

Background

As publishing is essential but competitive for researchers, difficulties in writing and submitting medical articles to biomedical journals are disabling. The DIAzePAM (Difficultés des Auteurs à la Publication d’Articles Médicaux) survey aimed to assess the difficulties experienced by researchers in the AP-HP (Assistance Publique – Hôpitaux de Paris, i.e., Paris Hospitals Board, France), the largest public health institution in Europe, when preparing articles for biomedical journals. The survey also aimed to assess researchers’ satisfaction and perceived needs.

Methods

A 39-item electronic questionnaire based on qualitative interviews was addressed by e-mail to all researchers registered in the AP-HP SIGAPS (Système d’Interrogation, de Gestion et d’Analyse des Publications Scientifiques) bibliometric database.

Results

Between 28 May and 15 June 2015, 7766 researchers should have received and read the e-mail, and 1191 anonymously completed the questionnaire (<45 years of age: 63%; women: 55%; physician: 81%; with PhD or Habilitation à Diriger des recherches––accreditation to direct research––: 45%). 94% of respondents had published at least one article in the previous 2 years. 76% of respondents felt they were not publishing enough, mainly because of lack of time to write (79%) or submit (27%), limited skills in English (40%) or in writing (32%), and difficulty in starting writing (35%). 87% of respondents would accept technical support, especially in English reediting (79%), critical reediting (63%), formatting (52%), and/or writing (41%), to save time (92%) and increase high-impact-factor journal submission and acceptance (75%). 79% of respondents would appreciate funding support for their future publications, for English reediting (56%), medical writing (21%), or publication (38%) fees. They considered that this funding support could be covered by AP-HP (73%) and/or by the added financial value obtained by their department from previous publications (56%).

Conclusions

The DIAzePAM survey highlights difficulties experienced by researchers preparing articles for biomedical journals, and details room for improvement.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-017-0371-z) contains supplementary material, which is available to authorized users.

Safety and efficacy of direct-acting antivirals for the treatment of chronic hepatitis C in a real-world population aged 65 years and older

The availability of direct-acting antiviral agents (DAA) regimens has expanded the pool of patients eligible for treatment. However, data on the virologic response and tolerability of DAAs in elderly patients are lacking. We evaluated the efficacy and safety of DAAs in patients with advanced fibrosis/cirrhosis in real-life practice with the focus on those aged ≥65 years. Between January and December 2015, all consecutive patients with HCV-related advanced fibrosis/cirrhosis treated with DAA at eleven tertiary referral centres in Emilia Romagna (Italy) were enrolled. Regimen choice was based on viral genotype and stage of disease, according to guidelines. The primary end point was sustained virologic response 12 weeks after the end of treatment (SVR12). Overall, 282 of 556 (50.7%) patients evaluated were elderly, most of them with cirrhosis. Antiviral therapy was stopped prematurely in four (1.4%) patients. Two patients, both with cirrhosis, died during treatment due to worsening of liver/renal function. SVR12 was achieved by 94.7% and was comparable to that obtained in patients aged <65 (P=.074). Similar data were also reported in subgroup of patients aged ≥75 years. All patients with advanced fibrosis achieved virologic response. SVR12 was 80.8% in Child-Pugh-Turcotte (CTP)-B cirrhosis and 95.4% in CTP-A (P=.013). According to genotype, the SVR12 was achieved in 172 of 181 (95%) with genotype 1b cirrhosis and in 44 of 48 (91.7%) with genotype 2 cirrhosis. In conclusions, in a real-world setting, DAAs are safe and effective in elderly patients with HCV-related advanced fibrosis/cirrhosis, but SVR12 is lower with worsening CTP class.

Results and limitations of humeral head resurfacing: 105 cases at a mean follow-up of 5 years

BACKGROUND

The objective of this study was to assess clinical and computed-tomography (CT) outcomes at least 2 years after humeral head resurfacing to treat concentric gleno-humeral osteoarthritis.

HYPOTHESIS

Humeral head resurfacing provides similar outcomes to those achieved with stemmed humeral head implants.

MATERIALS AND METHODS

This single-centre retrospective study included 40 Copeland™ and 65 Aequalis™ humeral resurfacing heads implanted between 2004 and 2012. Mean patient age at diagnosis was 64 years. The diagnoses were osteoarthritis with an intact (68%) or torn (21%) rotator cuff, avascular necrosis (5%), osteoarthritis complicating chronic instability (3%), post-traumatic osteoarthritis (2%), and chronic inflammatory joint disease (1%). Validated clinical scores, radiographs, and CT before surgery and at last follow-up were compared.

RESULTS

During the mean follow-up of 56 months, complications occurred in 24 implants. Revision surgery with reverse shoulder replacement was required in 18 cases, after a mean of 43.6 months, to treat glenoid wear or a rotator cuff tear. At last follow-up, for the implants that did not require revision surgery, the mean Constant score was 64/100. The implants had a mean varus of 5° and mean retroversion of -13.3°. The mean increase in glenoid cavity depth was 2.4mm. Mean increases in medial and lateral humeral offset were 1.9mm and 2.7mm, respectively. Pre-operative factors significantly associated with failure were rotator cuff tear (P=0.017) and glenoid erosion (P=0.001).

DISCUSSION

We found a high failure rate related to glenoid wear or progressive rotator-cuff impairment, although CT showed no evidence of implant malposition or overstuffing. Previous studies of stemmed humeral head implants showed better outcomes. Given the low medium-term prosthesis survival rate, we now reserve humeral head resurfacing for concentric osteoarthritis without glenoid erosions or rotator cuff damage.

LEVEL OF EVIDENCE

IV, retrospective study.

Validation and Factor Structure of the French-Language Version of the Emotional Appetite Questionnaire (EMAQ)

The concept of Emotional Eating (EE) is increasingly considered to be implicated in overeating and obesity, and in different subtypes of eating disorders. Among the self-report questionnaires assessing EE, the Emotional Appetite Questionnaire (EMAQ) includes recent advances in this area: it evaluates a broad range of emotions and situations both positive and negative, and the way they modulate food intake (decrease, stability, or increase). The main objective of our study was to further investigate the psychometric properties of the French version of the EMAQ in a large sample of students. Participants completed the EMAQ (n = 679), the DEBQ (Dutch Eating Behavior Questionnaire) (n = 75) and the CIDI-eating disorders screening (Composite International Diagnostic Interview) (n = 604). Factorial structure, reliability, and validity of the EMAQ were tested. Factorial analyses supported a two-factor (Positive and Negative) structure. The internal consistency indices were satisfactory and results suggest good test–retest reliability for the scale. Convergent and discriminant validity were confirmed from the significant correlations observed between the EMAQ scores and the DEBQ-EE subscale scores. Regarding associations with weight, whereas EMAQ negative scores were positively correlated with BMI, EMAQ positive scores were negatively correlated with BMI. Finally, EMAQ scores differed significantly depending on gender and risk for bulimia nervosa. This study supports the validity and the reliability of the EMAQ, which appears to be a promising instrument to better understand individual differences that could modulate food intake.

Assessment of quality of life, satisfaction with anticoagulation therapy, and adherence to treatment in patients receiving long-course vitamin K antagonists or direct oral anticoagulants for venous thromboembolism

INTRODUCTION

Direct oral anticoagulants (DOACs) have shown non-inferiority and ease of use compared to vitamin K antagonists (VKA) in the treatment of venous thromboembolism (VTE). No study so far has been directed toward real-life experience of outpatients receiving anticoagulants for VTE in France.

METHODS

This is an observational descriptive real-life epidemiological study, using three validated questionnaires (Morisky Medication Adherence Scale-8, EQ-5D, and part 2 of the Perception of Anticoagulant Treatment Questionnaire), to assess adherence, quality of life, and satisfaction in 100 VTE outpatients receiving anticoagulation therapy by VKA (primary or switched from DOAC to VKA) or by DOAC (primary or switched from VKA to DOAC).

RESULTS

Patients were very much satisfied with their treatment in both DOAC and VKA groups. Despite advantages of DOACs, therapeutic adherence was only moderate. The best adherence scores were observed in the primary VKA switched to DOAC for at least 3 months (S-DOAC) subgroup. Quality of life was better in the DOAC group mainly because of the absence of the requirement for blood testing. Most of the complaints concerned the pain/discomfort dimension in the VKA group and anxiety/depression dimension in the DOAC group.

CONCLUSION

Patients were satisfied with their anticoagulant treatment, especially when they were involved in choosing the anticoagulant, and the treatment suited them. Quality of life of patients in the DOAC group was better than in the VKA group, but adherence remains to be improved. This study highlights the importance of the physician-patient relationship, pretreatment initiation, and follow-up of any anticoagulation therapy throughout.

The International development of PROQOL-HCV: An instrument to assess the health-related quality of life of patients treated for Hepatitis C virus

BACKGROUND

Hepatitis C virus (HCV) compromises Health-related Quality of Life (HRQL) with detriments to Physical, Mental and Social health domains. Treatment with interferon and ribavirin is associated with side effects which further impair HRQL. New treatments appear potent, effective and tolerable. However, Patient Reported Outcomes instruments that capture the impact on HRQL for people with hepatitis C are largely non-specific and will be needed in the new treatment era. Therefore, we developed a conceptually valid multidimensional model of HCV-specific quality of life and pilot survey instrument, the Patient Reported Outcome Quality of Life survey for HCV (PROQOL-HCV).

METHODS

HCV patients from France (n = 30), Brazil (n = 20) and Australia (n = 20) were interviewed to investigate HCV-HRQL issues raised in the scientific literature and by treatment specialists. Interviews were recorded, transcribed and translated into English and French.

RESULTS

Fifteen content dimensions were derived from the qualitative analysis, refined and fitted to four domains: (1) Physical Health included: fatigue, pain, sleep, sexual impairment and physical activity; (2) Mental Health: psychological distress, psychosocial impact, and cognition; (3) Social Health: support, stigma, social activity, substance use; (4) TREATMENT: management, side effects, and fear of treatment failure. The impact of some dimensions extended beyond their primary domain including: physical activity, cognition, sleep, sexual impairment, and the three treatment dimensions. A bank of 300 items was constructed to reflect patient reports and, following expert review, reduced to a 72-item pilot questionnaire.

CONCLUSION

We present a conceptually valid multidimensional model of HCV-specific quality of life and the pilot survey instrument, PROQOL-HCV. The model is widely inclusive of the experience of hepatitis C and the first to include the treatment dimension.

A Three-Item Instrument for Measuring Daytime Sleepiness: The Observation and Interview Based Diurnal Sleepiness Inventory (ODSI)

STUDY OBJECTIVES

We aimed to develop a new three-item assessment tool for daytime sleepiness in older adults, the Observation and interview-based Diurnal Sleepiness Inventory (ODSI) and determine its validity, internal consistency, test-retest reliability, and optimal cutoff score.

METHODS

A total of 133 elderly subjects including 73 patients with obstructive sleep apnea (OSA) (mean age, 79 y) and 60 controls (mean age, 80 y) were consecutively enrolled and answered all questionnaires. The ODSI questionnaire was validated using the Epworth Sleepiness Scale considered as a gold standard. Reliability, validity, and cut-points were tested.

RESULTS

The ODSI has acceptable validity, internal consistency, and test-retest reliability properties. The ODSI has internal consistency and a reliability coefficient (Pearson rho) of 0.70 for its three items, which suggests strong reliability. The estimated sensitivity and specificity were 0.842 with 95% confidence interval [0.624; 0.945] and 0.851 [0.761; 0.911], respectively. The consistency of summated scale scores during test and retest sessions was high (r = 0.970, 95% bootstrap confidence interval [0.898; 0.991]). Receiver operating characteristic analysis suggests that a cut-point of 6 is effective for identifying older adults with excessive levels of daytime sleepiness.

CONCLUSIONS

The ODSI is a brief, valid, easy-to-administer three-item assessment that can screen for excessive daytime sleepiness among elderly patients with OSA.

Developmental Coordination Disorder, An Umbrella Term for Motor Impairments in Children: Nature and Co-Morbid Disorders

Background: Developmental Coordination Disorder (DCD) defines a heterogeneous class of children exhibiting marked impairment in motor coordination as a general group of deficits in fine and gross motricity (subtype mixed group) common to all research studies, and with a variety of other motor disorders that have been little investigated. No consensus about symptoms and etiology has been established.

Methods: Data from 58 children aged 6 to 13 years with DCD were collected on DSM-IV criteria, similar to DSM-5 criteria. They had no other medical condition and inclusion criteria were strict (born full-term, no medication, no occupational/physical therapy). Multivariate statistical methods were used to evidence relevant interactions between discriminant features in a general DCD subtype group and to highlight specific co-morbidities. The study examined age-calibrated standardized scores from completed assessments of psychological, neuropsychological, and neuropsychomotor functions, and more specifically the presence of minor neurological dysfunctions (MND) including neurological soft signs (NSS), without evidence of focal neurological brain involvement. These were not considered in most previous studies.

Results: Findings show the salient DCD markers for the mixed subtype (imitation of gestures, digital perception, digital praxia, manual dexterity, upper, and lower limb coordination), vs. surprising co-morbidities, with 33% of MND with mild spasticity from phasic stretch reflex (PSR), not associated with the above impairments but rather with sitting tone (p = 0.004) and dysdiadochokinesia (p = 0.011). PSR was not specific to a DCD subtype but was related to increased impairment of coordination between upper and lower limbs and manual dexterity. Our results highlight the major contribution of an extensive neuro-developmental assessment (mental and physical).

Discussion: The present study provides important new evidence in favor of a complete physical neuropsychomotor assessment, including neuromuscular tone examination, using appropriate standardized neurodevelopmental tools (common tasks across ages with age-related normative data) in order to distinguish motor impairments gathered under the umbrella term of developmental coordination disorders (subcortical vs. cortical). Mild spasticity in the gastrocnemius muscles, such as phasic stretch reflex (PSR), suggests disturbances of the motor pathway, increasing impairment of gross and fine motricity. These findings contribute to understanding the nature of motor disorders in DCD by taking account of possible co-morbidities (corticospinal tract disturbances) to improve diagnosis and adapt treatment programmes in clinical practice.

A reduced factor structure for the PROQOL-HIV questionnaire provided reliable indicators of health-related quality of life

OBJECTIVES

To identify a simplified factor structure for the PROQOL-human immunodeficiency virus (HIV) questionnaire to improve the measurement of the health-related quality of life (HRQL) of HIV-positive patients in clinical care and research settings.

STUDY DESIGN AND SETTING

HRQL data were collected using the eight-dimension PROQOL-HIV questionnaire from 2,537 patients (VESPA2 study). Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) validated a simpler four-factor structure and assessed measurement invariance (MI). Multigroup analysis assessed the effect of sex, age, and antiretroviral therapy (ART) on the resulting factor scores. Correlations with symptom and Short Form (SF)-12 self-reports assessed convergent validity.

RESULTS

Item analysis, EFA, and CFAs confirmed the validity [comparative fit index (CFI), 0.948; root mean square error of approximation, 0.064] and reliability (α's ≥ 0.8) of four dimensions: physical health and symptoms, health concerns and mental distress, social and intimate relationships, and treatment-related impact. Strong MI was demonstrated across sex and age (decrease in CFI <0.01). A multiple-cause multiple-indicator model indicated that HRQL correlated as expected with sex, age, and the ART status. Correlations of HRQL, symptom reports, and SF-12 scores evidenced convergent validity criterion.

CONCLUSION

The simplified factor structure and scoring scheme for PROQOL-HIV will allow clinicians to monitor with greater reliability the HRQL of patients in clinical care and research settings.

Type 1 and type 2 autoimmune hepatitis in adults share the same clinical phenotype

BACKGROUND

Autoimmune hepatitis (AIH) is historically classified into type 1 and type 2 on the basis of the autoantibody profile, anti-nuclear and/or anti-smooth muscle antibodies being the serological markers of type 1 AIH, whereas anti-liver/kidney microsomal antibody type 1 and/or anti-liver cytosol antibody type 1 characterise type 2 AIH.

AIM

To evaluate whether such a distinction is justified on the basis of different expression of the disease in adults.

METHODS

Twenty-six adult patients with type 2 AIH and 52 age- and sex-matched patients with type 1 AIH, representative of the entire cohort of adults with type 1 AIH, were compared at onset and during follow-up.

RESULTS

At diagnosis, median age was 26 years (range 17-53), female sex 86%, acute presentation 43%, severe liver histology 54%, cirrhosis 14%, complete response to treatment 52%, progression of the disease 17%, and median disease duration 72 months (range 12-280). HLA-DRB1*0301 was present in 26%, HLA-DRB1*0401 in 23% and HLA-DRB1*0701 in 25%. Clinical presentation, biochemical parameters, severe liver histology, genetic profile, response rate and progression of the disease were identical between type 1 and type 2 AIH.

CONCLUSION

There is not enough clinical, biochemical, histological or genetic reason to subdivide adults with autoimmune hepatitis into type 1 and type 2 on the basis of the autoantibody profile, and the term 'autoimmune hepatitis' without qualification should be preferred.

Alexithymia, a compounding factor for eating and social avoidance symptoms in anorexia nervosa

Socio-affective difficulties, in particular difficulties in representing, communicating and feeling emotions, may play a critical role in anorexia nervosa (AN). The aim of this longitudinal study was to explore the links between alexithymia and two types of difficulties in AN: eating symptoms and social avoidance. Sixty adolescent girls with AN were recruited following hospitalisation in a specialised department. They completed self-administered questionnaires of alexithymia (TAS-20), of central symptoms of the eating disorders (EDI), and of anxious and depressive affects (SCL-90). Anxiety and social avoidance were assessed in the course of a standardised interview (LSAS). These measures were performed at inclusion, and at 6-, 12- and 18-months' follow-up. The relationship between TAS-20 and EDI or LSAS total scale scores across the four time points was assessed using mixed-effects models, including anxiety, depression, BMI, anorexia subtype, and age as co-factors. Partial least square regression was used to refine this multivariate analysis at subscale level, at inclusion and 18 months. Robust associations between TAS-20 and EDI scores were found, independently from anxious and depressive scores, nutritional state and AN subtype. These effects appeared more particularly linked to the implication of the dimensions difficulties identifying and describing feelings, interpersonal mistrust, feelings of inadequacy and interoceptive awareness deficit. There was also a durable association between alexithymia and social anxiety and avoidance, after adjusting for the confounding effects of depression, and anxiety, and the state of starvation. Difficulties in describing feelings appeared particularly involved here. Thus alexithymia does appear as a factor in the persistence of disorders in AN, and difficulties identifying and describing feelings could compound the social difficulties and major the relational isolation of these patients.

Psychometric assessment of health-related quality of life and symptom experience in HIV patients treated with antiretroviral therapy

PURPOSE

Symptoms which are found to cluster consistently can have synergistic effects on patient outcomes and therefore may serve to predict morbidity or disentangle disease progression from comorbid conditions. Self-report HIV-specific symptom and HRQL measures were jointly analyzed in HIV-positive patients under different antiretroviral treatment regimens.

METHODS

The responses of N = 365 patients from four countries to the 9-item Physical Health and Symptom dimension of the PROOQL-HIV questionnaire and an HIV Symptom checklist were analyzed. Item response modeling and multidimensional scaling were used to derive HRQL scores free of any differential item functioning related to gender and target language and to summarize symptom co-expression in patients under protease inhibitor treatment(PI, N = 164, 45%) versus other medication (Non-PI).

RESULTS

Women reported poorer HRQL (p = 0:037), and HRQL did not differ between the target languages of French, English, and Thai. Fatigue, muscular pain, or difficulties falling asleep was the most frequently reported symptoms [35%). PI versus Non-PI patients exhibited different pattern of symptoms with lipodystrophy-related and gastrointestinal symptoms forming well-separated clusters in the PI group. A higher number of symptoms were associated with lower HRQL (p < 0:001), and patients taking PIs reported lower HRQL (p = 0:003). Patients in both groups who reported fatigue, sexual dysfunction, or several lipodystrophy-related symptoms had poorer quality of life.

The influence of eating disorders on mothers' sensitivity and adaptation during feeding: a longitudinal observational study

BACKGROUND

Parents with past and current eating disorders (ED) have been shown to report troubles nourishing their infants. This could increase the risk of infant feeding problems linked to maternal anxiety and depression. It is not clear how mothers' eating difficulties before pregnancy and at the time of birth can affect infant's feeding. We aimed to specify the impact of eating disorders on mothers' adaptation and sensitivity to their offspring during feeding, by comparing a population of mothers with eating disorders and controls.

METHODS

Twenty-eight women agreed to participate in interviews and filmed mother-baby interactions. Pregnant women consulting at an obstetric unit for care follow-up were screened and tested for symptoms of eating disorders with the EDE-Q Questionnaire (Eating Disorders Examination Questionnaire) and the EDE Interview (Eating Disorders Examination Interview). Infant functional troubles and mothers' sensitivity were investigated through the Symptom Check List. Reciprocal adaptation during feeding with their new-borns was filmed and analysed with the Chatoor Infant Feeding Scale. Before pregnancy, two women suffered from anorexia, three suffered from bulimia, three had binge eating symptoms and two were diagnosed with EDNOS (Eating Disorders Not Otherwise Specified).

RESULTS

Mothers suffering from ED tended to show more difficult interactive patterns in terms of dyadic reciprocity when feeding their babies compared with mothers with no symptoms of eating disorders. In the interviews, other than the behavioural data gathered, ED mothers expressed feeling more dissatisfaction and uneasiness during feeding.

CONCLUSIONS

Pregnancy seems to be an useful period for interviewing women on eating disorders, allowing for the design and implementation of prevention programmes based on mothers' narratives and infant/mother observations and treatment.

Electronic versus paper-based assessment of health-related quality of life specific to HIV disease: reliability study of the PROQOL-HIV questionnaire

BACKGROUND

Electronic patient-reported outcomes (PRO) provide quick and usually reliable assessments of patients' health-related quality of life (HRQL).

OBJECTIVE

An electronic version of the Patient-Reported Outcomes Quality of Life-human immunodeficiency virus (PROQOL-HIV) questionnaire was developed, and its face validity and reliability were assessed using standard psychometric methods.

METHODS

A sample of 80 French outpatients (66% male, 52/79; mean age 46.7 years, SD 10.9) were recruited. Paper-based and electronic questionnaires were completed in a randomized crossover design (2-7 day interval). Biomedical data were collected. Questionnaire version and order effects were tested on full-scale scores in a 2-way ANOVA with patients as random effects. Test-retest reliability was evaluated using Pearson and intraclass correlation coefficients (ICC, with 95% confidence interval) for each dimension. Usability testing was carried out from patients' survey reports, specifically, general satisfaction, ease of completion, quality and clarity of user interface, and motivation to participate in follow-up PROQOL-HIV electronic assessments.

RESULTS

Questionnaire version and administration order effects (N=59 complete cases) were not significant at the 5% level, and no interaction was found between these 2 factors (P=.94). Reliability indexes were acceptable, with Pearson correlations greater than .7 and ICCs ranging from .708 to .939; scores were not statistically different between the two versions. A total of 63 (79%) complete patients' survey reports were available, and 55% of patients (30/55) reported being satisfied and interested in electronic assessment of their HRQL in clinical follow-up. Individual ratings of PROQOL-HIV user interface (85%-100% of positive responses) confirmed user interface clarity and usability.

CONCLUSIONS

The electronic PROQOL-HIV introduces minor modifications to the original paper-based version, following International Society for Pharmacoeconomics and Outcomes Research (ISPOR) ePRO Task Force guidelines, and shows good reliability and face validity. Patients can complete the computerized PROQOL-HIV questionnaire and the scores from the paper or electronic versions share comparable accuracy and interpretation.

Levels of autistic traits in anorexia nervosa: a comparative psychometric study

BACKGROUND

A number of characteristics associated with Autism Spectrum Disorders (ASD) are over-represented among patients with Anorexia Nervosa (AN) as well as among relatives of these patients. Yet the co-occurrence of autistic traits in AN has not been fully explored and no previous study has directly compared self-reported evaluations of cognitive and socio-affective skills in AN and ASD.

METHODS

We aimed to determine the degree of overlap between AN and ASD from scores on questionnaires classically used to measure ASD impairments. Fifteen AN participants, 15 ASD participants and two groups of matched controls completed a battery of self-reports measuring: autistic traits (Autism-Spectrum Quotient), empathy (Empathy Quotient-short and Interpersonal Reactivity Index), systemizing (Systemizing Quotient-short) and alexithymia (Bermond-Vorst Alexithymia Questionnaire-B). Univariate comparisons of mean totalled scores were performed on each measure (patients vs. controls, and AN vs. ASD), and a Principal Component Analysis was used to study subject proximities in a reduced-factor space constructed from AQ, BVAQ-B and IRI subscales.

RESULTS

These analyses revealed similarities in a few cognitive domains (Attention Switching, Perspective Taking and Fantasy, lack of emotional introspection) and in some nonspecific affective dimensions (depression and feelings of distress), but also marked dissimilarities in social skills (the ability to communicate emotions to others, empathizing).

CONCLUSION

The AN and ASD participants reported similar needs for sameness, and similar difficulties understanding their emotions and taking the perspective of another, but contrasting abilities to feel concerned in interpersonal situations. Our mixed findings encourage further exploration of transdiagnostic similarities and associations between these disorders.

Investigating emotional impairments in adults with autism spectrum disorders and the broader autism phenotype

There is an increasing interest in the socio-affective atypicalities observed in adults with autism spectrum disorder (ASD). The aim of this study was to further explore emotional responsiveness in adults with ASD using well-validated self-reports of alexithymia and to determine whether anhedonic features are part of a broader autism phenotype (BAP). Participants comprised 38 adults with ASD, 87 parents of ASD individuals and 47 typical controls. All participants completed the Autism Spectrum Quotient (AQ), the 20-item Toronto Alexithymia Scale, and the Bermond-Vorst Alexithymia Questionnaire, as well as the Chapman Physical and Social Anhedonia Scales. The ASD group differed from controls and parents on most measures, with the exception of physical and social anhedonia, relative to parents. Parents differed from controls on social anhedonia, and a higher proportion of parents were classed as alexithymic, relative to controls. Cluster analysis revealed that some parents share more similarities with ASD participants than with controls. The results suggest that socio-affective impairments characteristic of ASD are part of the BAP.

HIV-related stigma and physical symptoms have a persistent influence on health-related quality of life in Australians with HIV infection

BACKGROUND

The health-related quality of life (HRQL) of people living with HIV infection is an important consideration in HIV management. The PROQOL-HIV psychometric instrument was recently developed internationally as a contemporary, discriminating HIV-HRQL measure incorporating influential emotional dimensions such as stigma. Here we present the first within-country results of PROQOL-HIV using qualitative and quantitative data collected from a West Australian cohort who participated in the development and validation of PROQOL-HIV, and provide a comprehensive picture of HRQL in our setting.

METHODS

We carried out a secondary analysis of data from Australian patients who participated in the international study: 15 in-depth interviews were conducted and 102 HRQL surveys using the PROQOL-HIV instrument and a symptom questionnaire were administered. We employed qualitative methods to extract description from the interview data and linear regression for exploration of the composite and sub-scale scores derived from the survey.

RESULTS

Interviews revealed the long-standing difficulties of living with HIV, particularly in the domains of intimate relationships, perceived stigma, and chronic ill health. The novel PROQOL-HIV instrument discriminated impact of treatment via symptomatology, pill burden and treatment duration. Patients demonstrated lower HRQL if they were: newly diagnosed (p=0.001); naive to anti-retroviral treatment (p=0.009); reporting depression, unemployment or a high frequency of adverse symptoms, (all p<0.001). Total HRQL was notably reduced by perceived stigma with a third of surveyed patients reporting persistent fears of both disclosing their HIV status and infecting others.

CONCLUSIONS

The analysis showed that psychological distress was a major influence on HRQL in our cohort. This was compounded in people with poor physical health which in turn was associated with unemployment and depression. People with HIV infection are living longer and residual side effects of the earlier regimens complicate current clinical management and affect their quality of life. However, even for the newly diagnosed exposed to less toxic regimens, HIV-related stigma exerts negative social and psychological effects. It is evident that context-specific interventions are required to address persistent distress related to stigma, reframe personal and public perceptions of HIV infection and ameliorate its disabling social and psychological effects.

Refining developmental coordination disorder subtyping with multivariate statistical methods

BACKGROUND

With a large number of potentially relevant clinical indicators penalization and ensemble learning methods are thought to provide better predictive performance than usual linear predictors. However, little is known about how they perform in clinical studies where few cases are available. We used Random Forests and Partial Least Squares Discriminant Analysis to select the most salient impairments in Developmental Coordination Disorder (DCD) and assess patients similarity.

METHODS

We considered a wide-range testing battery for various neuropsychological and visuo-motor impairments which aimed at characterizing subtypes of DCD in a sample of 63 children. Classifiers were optimized on a training sample, and they were used subsequently to rank the 49 items according to a permuted measure of variable importance. In addition, subtyping consistency was assessed with cluster analysis on the training sample. Clustering fitness and predictive accuracy were evaluated on the validation sample.

RESULTS

Both classifiers yielded a relevant subset of items impairments that altogether accounted for a sharp discrimination between three DCD subtypes: ideomotor, visual-spatial and constructional, and mixt dyspraxia. The main impairments that were found to characterize the three subtypes were: digital perception, imitations of gestures, digital praxia, lego blocks, visual spatial structuration, visual motor integration, coordination between upper and lower limbs. Classification accuracy was above 90% for all classifiers, and clustering fitness was found to be satisfactory.

CONCLUSIONS

Random Forests and Partial Least Squares Discriminant Analysis are useful tools to extract salient features from a large pool of correlated binary predictors, but also provide a way to assess individuals proximities in a reduced factor space. Less than 15 neuro-visual, neuro-psychomotor and neuro-psychological tests might be required to provide a sensitive and specific diagnostic of DCD on this particular sample, and isolated markers might be used to refine our understanding of DCD in future studies.

Significant correlation between a set of genetic polymorphisms and a functional brain network revealed by feature selection and sparse Partial Least Squares

Brain imaging is increasingly recognised as an intermediate phenotype to understand the complex path between genetics and behavioural or clinical phenotypes. In this context, a first goal is to propose methods to identify the part of genetic variability that explains some neuroimaging variability. Classical univariate approaches often ignore the potential joint effects that may exist between genes or the potential covariations between brain regions. In this paper, we propose instead to investigate an exploratory multivariate method in order to identify a set of Single Nucleotide Polymorphisms (SNPs) covarying with a set of neuroimaging phenotypes derived from functional Magnetic Resonance Imaging (fMRI). Recently, Partial Least Squares (PLS) regression or Canonical Correlation Analysis (CCA) have been proposed to analyse DNA and transcriptomics. Here, we propose to transpose this idea to the DNA vs. imaging context. However, in very high-dimensional settings like in imaging genetics studies, such multivariate methods may encounter overfitting issues. Thus we investigate the use of different strategies of regularisation and dimension reduction techniques combined with PLS or CCA to face the very high dimensionality of imaging genetics studies. We propose a comparison study of the different strategies on a simulated dataset first and then on a real dataset composed of 94 subjects, around 600,000 SNPs and 34 functional MRI lateralisation indexes computed from reading and speech comprehension contrast maps. We estimate the generalisability of the multivariate association with a cross-validation scheme and demonstrate the significance of this link, using a permutation procedure. Univariate selection appears to be necessary to reduce the dimensionality. However, the significant association uncovered by this two-step approach combining univariate filtering and L1-regularised PLS suggests that discovering meaningful genetic associations calls for a multivariate approach.

Subtypes of developmental coordination disorder: research on their nature and etiology

Children with Developmental Coordination Disorder (DCD) are a group embracing clumsiness and developmental dyspraxia. Our study provides a better understanding of the nature of DCD and its etiology, and identifies subtypes of dyspraxia. Forty-three children with DCD (5-15 years) were enrolled on the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV-TR]; American Psychiatric Association, 2000) criteria. Extensive standardized evaluations were conducted. We distinguished from two patterns of "pure" developmental dyspraxia: ideomotor and visual-spatial/visual-constructional, and mix dyspraxia with more co-morbidities. Our study provides a better understanding of the nature of DCD, and sheds light on its etiology and brain dysfunction, so as to identify subtypes of developmental DCD/dyspraxia with specific clinical criteria.

Superposition catastrophe and form-motion binding

Numerous studies indicate that perceiving global object motion results from the integration of local component motions across space and time. Less attention has been paid to the issue of motion selection, necessary to avoid spurious associations of component motions belonging to different objects and to solve the so-called "superposition catastrophe problem" (F. Rosenblatt, 1961). We address this issue using outlines of geometrical shapes moving behind apertures that concealed their vertices such that recovering their global motion requires the selection and integration of some, but not all, component motions. Depending on which local motions are selected for motion integration, these stimuli yield the perception of either expansion/contraction, of global translation, or of segments moving independently. We show that the selection process depends on local and global stimulus parameters, including the local direction of figure's line-endings or the spatial configuration of component motions. In contrast, motion selection depends less on the width-i.e., spatial frequency content-or polarity of the edges. Finally, synchronous temporal modulation of component motions in the gamma range has little effect on motion selection. These results indicate that selecting component motions for motion integration is primarily determined by form constraints. As a consequence, current models assuming that mutually consistent component motions are bounded in a velocity space-lacking spatial organization should be revised to account for the present data. Alternately, interactions between visual areas selectively processing form and motion could be introduced in order to account for the perceptual binding of moving objects.