Ahmed Jebrane

Using a Multi-Locus Microsatellite Typing method improved phylogenetic distribution of Candida albicans isolates but failed to demonstrate association of some genotype with the commensal or clinical origin of the isolates.

The dimorphic yeast Candida albicans is a component of the normal microflora at the mucosal surfaces of healthy individuals. It possesses an array of phenotypic properties considered as virulence traits that contribute to pathogenicity of the yeast in immuno-compromised patients. We addressed the question of the pathogenicity of lineages of C. albicans with regard to their genotype in three series of C. albicans isolates (a series of commensal isolates collected in healthy individuals, a group of bloodstream isolates and a group of non-bloodstream clinical isolates) using a Multi-Locus Microsatellite Typing (MLMT) approach based on the analysis of the polymorphism of 11 microsatellite loci. The MLMT analysis of the three series, corresponding to 174 C. albicans isolates, gave a 100% typability to the method, with a DP index of 0.999. The UPGMA analysis showed that the isolates segregated in eight phylogenetic groups. Interestingly, the clustering was comparable when using NJ and MS-tree algorithms and a good concordance index of the clustering was observed with MLST. All in all our data strongly indicated MLMT as a reliable tool for DNA-typing studies in C. albicans. Isolates from healthy and non-healthy individuals segregated at the same proportions into the eight phylogenetic groups, suggesting that isolates of different origin share the same overall pathogenicity. Surprisingly allelic frequencies at the HIS3 microsatellite differed significantly in commensal isolates (group A) from pooled groups B and C (clinical isolates), raising the possibility that some individual alleles at the HIS3 microsatellite may be associated with distinct pathogenic profiles in C. albicans.

A prospective analysis of the genotypic diversity and dynamics of the Candida albicans colonizing flora in neutropenic patients with de novo acute leukemia

This study was aimed at investigating the dynamics and heterogeneity of C. albicans flora in patients with de novo acute leukemia. Its findings suggest that genetic evolution of the colonizing C. albicans flora is uncommon in patients with acute leukemia. Background Genotyping studies have shown heterogeneity of Candida albicans flora in patients with human immunodeficiency virus infection, with possible co-existence of multiple clones with distinct resistance patterns. We report the result of a prospective study aimed at investigating the dynamics and heterogeneity of C. albicans flora in patients with de novo acute leukemia. Design and Methods Between 2001 and 2003, 66 consecutive adults with newly diagnosed acute leukemia were monitored for Candida colonization. From 19 patients with repeated multi-site C. albicans colonization, eight were randomly selected and multiple isolates from each individual mucosal site were genotyped sequentially over time using microsatellite markers. Results Despite topical use of polyenes, 60.6% of the patients were colonized repeatedly and at multiple sites. Altogether, 2,730 peripheral samples were cultured, 379 (13.9%) of which yielded yeasts. C. albicans was the most common species recovered (68%). From eight randomly selected patients colonized with C. albicans, 429 isolates were genotyped. Seven patients carried a unique genotype which was identical in all body niches and over the period of study. In one case, minor genotypic differences were observed. None of the patients shared C. albicans clones with identical genotypic profiles. Candidemia occurred in one of eight patients and the blood strain genotype did not differ from those of colonizing isolates. The genotypic profile was not altered by topical and/or systemic use of antifungal agents in any of the patients. Conclusions In patients with de novo acute leukemia, genetic evolution of the colonizing C. albicans flora and selection of variants or replacement of the original strain upon antifungal drug pressure or nosocomial transmission are rare events.

Diagnostic profiles determined by the C.A.R.T procedure: IBD patients and fatigue

Fatigue is common in IBD. It remains a complex phenomenon with primary factors related to the disease and secondary factors (depression, anxiety, sleep disturbances, pain) whose respective importance and organization are difficult to determine. By using the C.A.R.T. procedure, the diagnostic variables of 108 IBD-related fatigue patients were determined globally, according to their sex and the clinical activity of their disease. Results underline the diversity of diagnostic profiles in which psychological variables have significant influence. It is important to consider fatigue according to profiles that best illustrate its complexity and allow for identifying better potentially remediable factors.

Personality and fatigue perception in a sample of IBD outpatients in remission: A preliminary study

BACKGROUND AND AIMS Fatigue is considered as a feature of IBD. Nevertheless, medical variables would partly explain this complex phenomenon. Psychological variables would be especially connected to fatigue for patients in remission. Moreover, personality is known to be linked to the fatigue of patients with CFS. This preliminary study aimed to determine if personality dimensions are linked to the perception of fatigue in IBD. METHODS 81 IBD outpatients in remission completed the MFI (fatigue); ISI, EES (sleep disturbances); TCI-R (personality); HADS (depression and anxiety). Medical data were collected (ferritin, C-reactive protein, number of flare-ups, number of hospitalizations, duration of the disease and surgical sequelae). RESULTS With the exception of surgical sequelae, none of the medical variables was linked to fatigue perception. Anxiety and sleep disturbances were the most continuously connected to fatigue perception. Significant relationships were observed between personality categorization on Persistence, Self-Directness and the level of fatigue. CONCLUSION In order to improve vitality in IBD patients in remission, identification and treatment of psychological aspects should become a dimension of disease management. Fatigue should not be considered only as a direct feature of IBD.

Relationships between Coping Strategies and Defense Mechanisms in Sport Performance

In an exploratory study, the relationships between two major concepts in psychological adjustment, coping strategies, and defense mechanisms were investigated. Sport competition is an example of a real-world context in which peoples responses to stressful situations can be investigated. The extent to which participants reported different uses of coping strategies and defense mechanisms was assessed in terms of performance. 26 elite kayakers were classified into one of two groups, depending on the discrepancy between their standard performance and their performance in competition. Correlations were found among the coping strategies of seeking social support, positive reappraisal/planful problem solving, and mature defenses and between the coping strategy of distancing/avoidance and immature defenses. The results of multivariate and univariate analyses confirmed a significantly different use of coping strategies and defense mechanisms between the two performance groups. In light of these findings, certain recommendations in terms of methodology and application are warranted. Coping strategies and defense mechanisms should be studied to improve adjustment to sport performance.

Empirical and theoretical study of atelostomate (Echinoidea, Echinodermata) plate architecture: using graph analysis to reveal structural constraints

Abstract. Describing patterns of connectivity among organs is essential for identifying anatomical homologies among taxa. It is also critical for revealing morphogenetic processes and the associated constraints that control the morphological diversification of clades. This is particularly relevant for studies of organisms with skeletons made of discrete elements such as arthropods, vertebrates, and echinoderms. Nonetheless, relatively few studies devoted to morphological disparity have considered connectivity patterns as a level of morphological organization or developed comparative frameworks with proper tools. Here, we analyze connectivity patterns among apical plates in Atelostomata, the most diversified clade among irregular echinoids. The clade comprises approximately 1600 fossil and Recent species (e.g., 25% of post-Paleozoic species of echinoids) and shows high levels of morphological disparity. Plate connectivity patterns were analyzed using tools and statistics of graph theory. To describe and explore the diversity of connectivity patterns among plates, we symbolized each pattern as a graph in which plates are coded as nodes that are connected pairwise by edges. We then generated a comparative framework as a morphospace of connections, in which the disparity of plate patterns observed in nature was mapped and analyzed. Main results show that apical plate patterns are both highly disparate between and within atelostomate groups and limited in number; overall, they also constitute small, compact, and simple structures compared to possible random patterns. Main traits of the evolution of apical plate patterns reveal the existence of strong morphogenetic constraints that are phylogenetically determined. In contrast, evolutionary radiations within atelostomates were accompanied by a clear increase in disparity, suggesting a release of some constraints at the origin of clades.

The causal representation of outpatients with Crohn’s disease: is there a link between psychological distress and clinical disease activity?

Objectives: Because of the fluctuating and occasional character of Crohn’s disease (CD), patients have to cope with a changeable condition of health. Personal perceived control is known to be an important element of adaptation to their medical condition. The objectives of this work are to determine if perceived personal control is predictive of the clinical activity of the disease and of psychological distress (depression, anxiety). Methods: The Hospital Anxiety Depression Scale (HADS), the causal dimension scale and the Clinical Global Impression (CGI; assessing perceived severity) were administered to 160 patients affected by Crohn’s disease. Indicators of inflammation (CRP), disease duration and clinical activity of the disease were also asessed. Results: Globally, CD patients perceive their disease as being personally neither controllable nor uncontrollable. Whereas psychological distress is significantly higher when the disease is active, the relationship between the variables appears complex. The feeling of personal control is explained by the clinical activity of the disease (p=.0001) and by the perception that CD is unstable (p<.00001) and globally impacts the life of patients (p=.001). Nevertheless perception of personal control does not explain the clinical activity of the disease. Finally, psychological distress is explained by the perception that the medical team is unable to control the disease (p=.00001) and by the global consequences of the disease on life (p<.005). Conclusions: Psychological treatments should take these dimensions into account so as to improve the well-being and medical conditions of patients.