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Biomedical subjects

B Falissard

Publications and source records attributed to B Falissard.

36 records · Page 2Linked to original sources
PubMed2000

Sleep and alertness in children with ADHD.

OBJECTIVE: To evaluate sleep and alertness and to investigate the presence of possible underlying sleep/wake disorders in children with attention-deficit/hyperactivity disorder (ADHD). METHOD: After 3 nights of adaptation in a room reserved for sleep studies in the department of child psychiatry, children underwent polysomnography (PSG) followed by the Multiple Sleep Latency Test (MSLT) and reaction time tests (RT) during the daytime. Thirty boys diagnosed as having ADHD (DSM-IV), aged between 5 and 10 years, and 22 age- and sex-matched controls participated in the study. All children were medication-free and showed no clinical signs of sleep and alertness problems. RESULTS: No significant differences in sleep variables were found between boys with ADHD and controls. The mean latency period was shorter in children with ADHD. Significant differences were found for MSLT 1, 2 and 3 (p < .05). Mean reaction time was longer in children with ADHD, with significant differences in all tests (p < .05). Number and duration of sleep onsets measured by the MSLT correlated significantly with the hyperactivity-impulsivity and inattentive-passivity indices of the CTRS and CPRS. CONCLUSION: Children with ADHD were more sleepy during the day, as shown by the MSLT, and they had longer reaction times. These differences are not due to alteration in the quality of nocturnal sleep. The number of daytime sleep onsets and the rapidity of sleep-onsets measured as MSLT were found to be pertinent physiological indices to discriminate between ADHD subtypes. These results suggest that children with ADHD have a deficit in alertness. Whether this deficit is primary or not requires further studies.

Adult↗
PubMed1999

Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. A randomized, controlled trial.

BACKGROUND: Chlorhexidine is better than povidone-iodine for care of catheter sites, but it is not known whether chlorhexidine is superior in reducing blood culture contamination. OBJECTIVE: To determine whether alcoholic chlorhexidine is a more effective skin antiseptic for collection of blood cultures than aqueous povidone-iodine. DESIGN: Randomized, controlled trial. SETTING: Three adult intensive care units in a French university hospital. PATIENTS: 403 adults who had at least one blood culture drawn through a peripheral vein. INTERVENTIONS: Patients were randomly assigned to receive skin preparation with an aqueous solution of 10% povidone-iodine or an alcoholic solution of 0.5% chlorhexidine before phlebotomy. MEASUREMENTS: Contamination rates of blood cultures. RESULTS: Of 2041 blood cultures collected in 403 patients, 124 yielded pathogens. Chlorhexidine reduced the incidence of blood culture contamination more than povidone-iodine (14 of 1019 cultures [1.4%] compared with 34 of 1022 cultures [3.3%]; odds ratio, 0.40 [95% CI, 0.21 to 0.75]; P = 0.004). CONCLUSION: Skin preparation with alcoholic chlorhexidine is more efficacious than skin preparation with aqueous povidone-iodine in reducing contamination of blood cultures.

Adult↗
PubMed1999

"Silent" presentation of veno-occlusive disease after liver transplantation as part of the process of cellular rejection with endothelial predilection.

Hemorrhagic centrilobular necrosis and fibrous stenosis of hepatic venules, suggesting veno-occlusive disease (VOD) have rarely been observed after orthotopic liver transplantation (OLT). The aim of this study was to determine the prevalence of this syndrome after OLT in relation to the course with particular reference to acute rejection and to azathioprine administration. VOD was identified in 19 of 1,023 patients transplanted over a 9-year period. VOD occurred at a median of 30 days posttransplantation, without clear cut clinical evidence for hepatic vein outlet obstruction. Seventeen of the 19 patients had an episode of acute rejection before or at the time of VOD. These episodes were compared with that of patients without VOD. In patients with VOD, portal inflammation and endothelialitis were enhanced (P =.014 and P =.048) and endothelialitis was also higher than bile duct damage (P =.03). The incidence of a centrilobular endothelialitis for both groups was not different although an increased trend was observed in the study group (64% vs. 46%; P =.18). The incidence of persistent rejection was similar between both groups (47% vs. 41%). The incidence of chronic rejection was higher in the study group (29% vs. 10%; P =. 04). All patients with VOD received azathioprine as part of immunosuppressive regimen. Despite azathioprine withdrawal, zone 3 changes persisted in 57% of patients. In conclusion, the incidence of VOD was 1.9% after OLT. The association of prominent endothelial involvement and VOD with acute rejection in most cases suggests an immunological phenomenon.

Adult↗
PubMed1999

Abnormal psychosocial situations among inpatients from a child and adolescent psychiatric department in a teaching hospital in France.

In order to examine the relationships between Associated Abnormal PsychoSocial Situations and psychiatric disorders in children and adolescents, an exploratory analysis using Axis V of the ICD-10 was performed on 1050 child and adolescent psychiatric inpatients. A logistic regression analysis was completed with respect to four groups of DSM-III-R diagnostic categories (Emotional Disorders, Disruptive Behavior Disorders, Specific Developmental Disorders, Non Specific Developmental Disorders). AAPSS were more frequently found in children and adolescents with Emotional Disorders or Disruptive Behavior Disorders than in those with Developmental Disorders but there was no diagnostic specificity in the distribution of AAPSS.

Adolescent↗
PubMed1997

Further epidemiological evidence for anticipation in schizophrenia.

Anticipation describes an inheritance pattern within a pedigree in which disease severity increases, and/or age at onset decreases, in successive generations. This phenomenon has been described in different samples of schizophrenic subjects, and could explain many inconsistencies in the inheritability of schizophrenia. Anticipation is, however, subject to numerous and significant biases, partially controlled by different methodologies used in different studies. We analyzed the anticipation effect on an original sample of schizophrenic patients (n = 57) who had at least one other schizophrenic in their family belonging to another generation (father/mother, uncle/aunt, son/daughter). We tested the anticipation effect according to previously published methodologies, such as percentages of parent-child pairs showing negative versus positive anticipation, comparison of anticipation limited to parent-child or uncle-nephew pairs, anticipation analysis on the basis of families with unilineal origins only, and comparison of the age at onset-survival distribution of the two generations. The 31 schizophrenic subjects who belonged to the younger generation had a significantly earlier age at onset (24.58 years) than the 26 schizophrenic subjects who belonged to the older generation (36.46 years). Whatever the method used to control biases, we significantly found earlier age at onset for schizophrenic patients from the younger generation. There is strong evidence for the existence of the anticipation effect in schizophrenia in our sample, as well as in various others, which may elucidate numerous inconsistencies in clinical and epidemiological data which characterize schizophrenia. Looking for expanded trinucleotide repeats is thus the next step to detect the gene(s) that are potentially involved.

Adult↗
PubMed1996

TCR alpha beta gene usage for myelin basic protein recognition in healthy monozygous twins.

The pathogenic role of myelin basic protein (MBP)-specific T lymphocytes in multiple sclerosis (MS) has been suggested by the encephalitogenicity of MBP-specific T cells in experimental allergic encephalomyelitis (EAE). In humans, extensive analysis of TCRs involved in MBP recognition has led to conflicting results, varying from an intra- and/or interindividual restriction to high diversity in TCRAV/TCRBV gene usage. We previously established MBP-specific T cell lines (TCLs) from healthy monozygous twins and characterized their fine epitope specificity. In this study, we report on the TCR alpha beta gene usage of 52 of these MBP TCLs that are specific for epitopes recognized by both co-twins within the same pair. High overall diversity in the TCR alpha and TCR beta genes used for recognition of this self-Ag, MBP, was observed. Variable genes belonging to 19 different TCRAV and 16 different TCRBV subfamilies are expressed by the 52 TCLs herein studied. In co-twins, TCLs utilized genes belonging to common TCRAV and/or TCRBV gene subfamilies in 7 of 13 instances of shared epitope recognition. Statistical analysis of intrapair concordance for TCR gene usage for the recognition of a given peptide did not show any significant deviation from values that would be anticipated in the absence of genetic background effect.

Amino Acid Sequence↗
PubMed1996

Anticipation in schizophrenia: new light on a controversial problem.

OBJECTIVE: Anticipation, recently found in several neuropsychiatric disorders, is an inheritance pattern within a pedigree in which disease severity increases or age at onset decreases in successive generations. Demonstration of genetic anticipation in schizophrenia could be of heuristic value, since unstable trinucleotide repeat DNA is known to be the biological basis of anticipation. However, to overcome one of the major ascertainment biases that might mimic anticipation--namely, the fact that patients in different generations are not interviewed at the same age, resulting in a greater chance of finding a later age at onset in the older generation--a new method of investigating anticipation was used. METHOD: The study subjects were 97 systematically ascertained schizophrenic patients belonging to 24 families with at least two generations affected who were identified during a 1-year prevalence study in a limited geographical area of Reunion Island (Indian Ocean). A method of calculating expected age at onset according to age at interview was used in the analyses. RESULTS: In the younger generation of patients, the observed age at onset (21.80 years) was earlier than the expected age at onset (24.95 years), demonstrating anticipation, even when five additional biases that can mimic this genetic effect--the proband effect, the presence of an affected father or mother, the bilineality of the illness, the fertility effect, and the cohort effect--were taken into account. CONCLUSIONS: Evidence for anticipation was demonstrated in this group of schizophrenic patients. This may help the search for pathological genes implicated in the genesis of schizophrenia.

Adult↗
PubMed1996

[The center effect in multicenter studies: fixed or random?].

The multiplication of multicentric clinical studies leads to a generalization of the use of a center effect in statistical analyses. In the simple situation where the dependent variable is quantitative and there is only a simple factor of interest, the formalisation of such a protocol corresponds to a two way ANOVA (with the factor of interest and the center factor) with generally a term of interaction. Even such a simple situation leads to interrogations, one of them being to determine whether the centre effect is fixed or random. In the first situation, the conclusion of the study will concern only the centres evaluated in the study, while in the second, the conclusion will concern the whole population from which the centers have been randomly selected. Such a generalizability has a cost: a loss of power in determining the effect of the factor of interest (the loss being as important as the interaction factor of interest x centre factor is large) and the necessity of sophisticated statistical software. This paper will focus on successively: the notion of ANOVA, of fixed or random effect (with the conceptual, formal and numerical differences that distinguish these two approaches). A numerical example is proposed.

Analysis of Variance↗
PubMed1993

The succession procedure for interim analysis: extensions for early acceptance of Ho and for flexible times of analysis.

The succession procedure is a new method for group sequential analysis based on a succession of significant tests. In this paper, the procedure is extended by the addition of a lower boundary, which allows the early acceptance of the null hypothesis Ho according to the stochastic curtailing approach. The succession procedure is also adapted to the type I error spending rate function alpha *(t), leading to the method of semisequential analysis for which the times of analysis need not be specified in advance.

Algorithms↗
PubMed1992

A new procedure for group sequential analysis in clinical trials.

Since Pocock (1977, Biometrika 64, 191-199), many methods have been developed for group sequential analysis of clinical trials. However, these methods remain underemployed partly because of inconsistencies of sequential testing [Berry (1987, The Statistician 36, 181-189)]. This paper considers a new approach, which, by requiring that a succession of interim analyses be significant at the alpha level, both preserves the overall significance level alpha and does not present some of the inconsistencies of the previous methods. Results are obtained for a normal or binary response and for survival data. A comparison with the usual group sequential testing is also presented.

Analysis of Variance↗
PubMed1991

Some extensions to a new approach for interim analysis in clinical trials.

There already exists many methods for group sequential analysis of clinical trials. A new approach suggests to preserve the overall type I error alpha by requiring that a succession of interim analyses be significant at the alpha level. In this paper, this procedure is extended. A rule for early acceptance of H0 is presented, with an extension for flexible number and times of analyses. A real example is given.

Clinical Trials as Topic↗
PubMed1991

[Interim analysis in therapeutic trials: a brief survey of current developments].

It is often interesting to introduce, in the plan of a clinical trial, the possibility to make interim analyses. However, this induces an increase of type one error and it is thus necessary to use appropriate statistical methods. Usual group sequential procedures are mentioned, just as more recent approaches like flexible methods with free number and time of analyses, or like the succession procedure.

Clinical Trials as Topic↗
PubMed1989

A program running under MS-DOS for the analysis of epidemiologic stratified or matched data.

Breslow and Day's method for computing the conditional likelihood of the logistic model in case of stratified samples requires, at each iteration the generation, for each stratum, of all the permutations of nc elements drawn from a total of nc + nt elements, where nc and nt are respectively the numbers of the cases and of the controls. This procedure rapidly proves costly in time as nc and nt increase, and also when nc and nt differ from one stratum to the next. The use of this technique on microcomputers is therefore limited. Presented here is an algorithm written in FORTRAN, based on a binary representation of the possible permutations, which readily permits the implementation of Breslow and Day's model on a microcomputer.

Algorithms↗
PubMedDate not supplied

[Patients with a complete or partial remission of Major Depressive Episode as part of Recurrent Major Depressive Disorder: description of ECLAIR study population].

Some guidelines and expert consensus consider the way of care management practices for the recurrent depressive disorder, particularly according to different identified risk factors for recurrence. But, few data are available about the way that these risk factors influence the care management of depressive recurrent patients during the partial or complete remission phase. Eclair study is a longitudinal observatory multicentric and national study, which describes the different risk factors that influence the psychiatrist decision about the following of patients suffering form Major Depressive Disorder (at least 3 Major Depressive Episode (MDE) according to DSM IV). This article presents the inclusion data (V0) of patients, with a focus on their demography characteristics and history of trouble, diagnosis, symptomatology evaluation (with CGI-S, HAM-D, Carroll scale and Sheehan scale) and Cloninger's personality questionnaire (TCI). A total of 596 patients with a recurrent depression either on partial remission (PaR) or complete remission (ToR) to their last episode at the selection, have been included. Complete remission was defined by the presence of a maximum of two criteria of MDE (according to DSM IV) excepted depressed mood and diminished interest or pleasure during at least two months with a HAM-D (17 items) score < 7 and partial remission was defined by the persistence of depressed symptoms but not sufficient to complete a diagnosis of MDE (according to DSM IV) associated with a HAM-D (17 items) score between 8 and 13 included. Mean HAM-D scores at V0 were 10.3 +/- 1.6 for PaR group and 4.0 +/- 1.9 for the ToR group. Free time since last episode was 6.5 +/- 10.5 months in ToR group and 11.2 +/- 16.9 months in PaR group (n = 385). Residual symptomatology between prior episodes was systematically present for 47.6% patients in PaR group, and for 26.7% patients ToR group. The feel to have a stressful daily life persisted for 62.5% of patient in PaR group and 34.3% in ToR group; 70.3% patients in PaR group and 57.9% patients in ToR group reported persistence of causal factor. The main collected risk factors for recurrence were the number of prior depressive episodes (64.9%), familial conflict existence (52.9%) and recent events of life (45.1%). In the TCI, a significant difference in comparison with the French normative data has been found for 3 dimensions: Harm Avoidance, Cooperativeness and Self-Directedness. Some differences were obtained for Novelty Seeking, Reward Dependence, and Self-Transcendence, but without sufficient clinical significance.This study confirms various characteristics about the unipolar depressive disorder, particularly the high risk of recurrence in patients with high number of previous episodes. In the research of predictive depressive recurrence signs, it would be interesting to focus on discriminating elements between complete remitted patients and partial remitted patients.

Adult↗
PubMedDate not supplied

Assessment of anxiety disorders in asthmatic children.

The study's objective was to determine whether the State Trait Anxiety Inventory for Children, Trait version (STAIC), is suitable for the assessment of DSM-IV anxiety disorders in asthmatic children and adolescents. Ninety-two outpatients were given a semistructured diagnostic interview. They completed STAIC; another questionnaire about anxiety, the Echelle Comportementale d'Anxiété et de Peurs (ECAP); and the Child Depression Inventory. The parents filled in the Child Behavior Check-List (CBCL) and the Conners Parent Rating Scale (CPRS). A group of healthy children was assessed with STAIC. Thirty asthmatic children had anxiety disorders. They had significantly higher STAIC scores than the nonanxious asthmatic and the nonasthmatic children. STAIC scores were independent of age and sex and were correlated with ECAP, CPRS anxiety subscore, CBCL total score, internalizing score, and CBCL anxiety-depression subscore. Internal consistency was 0.75. With a threshold value of 34 for anxiety disorders, this method had a sensitivity of 73% and a specificity of 70%. STAIC was thus a useful method for anxiety disorder screening in a pediatric population.

Adolescent↗