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A Pierson

Publications and source records attributed to A Pierson.

At least 19 recordsLinked to original sources
PubMed2002

Modulation of visual event-related potentials by emotional olfactory stimuli.

The objective of the present study was to determine whether an olfactory prime could modulate behavior and visual event-related potentials (ERPs) obtained in response to a visual stimulation representing female faces. More specifically, we tested the hypothesis that a pleasant odor could have effects on face perception: behavioral effects on subjective emotional estimation of faces, and on associated response times, and electrophysiological effects on the N400 and late positive complex or LPC. Experiments were performed in which subjects had to decide whether the presented face was pleasant or not, while visual ERPs were recorded. Faces were always primed with either a pleasant odor or a neutral olfactory stimulus (pure air). In order to test the effect of subject's awareness, participants were not informed that an odor would be presented in the experimental sessions. Responses were significantly shorter for unpleasant faces. However, no behavioral effects of the pleasant odor on response time or on evaluation of face pleasantness were observed. Late ERPs evoked by faces were modulated by the presence of a pleasant odor, even when subjects were neither warned nor aware of the presence of the odor: in a frontal site and after the diffusion of the odor, the LPC (appearing 550 ms after the presentation of the visual stimulus) evoked by unpleasant faces was significantly more positive than the LPC evoked by pleasant faces. This effect could reflect an enhanced alert reaction to unpleasant faces are preceded by an (incongrous) pleasant odor.

Adult↗
PubMed2002

[School-related injuries: incidence, causes, and consequences].

BACKGROUND: School accidents are frequent but little epidemiological information is available to guide prevention. In this study we examined the incidence, causes, and consequences of school accidents as a function of the pupil's characteristics. METHODS: An epidemiological study was conducted in all 2 396 adolescents attending two secondary school groups. Sociodemographic characteristics of the pupils and data on school accidents during a one-year period were collected using a questionnaire filled out by the school nurse in the presence of the victims. The chi-square independence test, Fisher's exact test and the logistic regression method were used for the statistical analysis. RESULTS: Sports and physical training (SPT) accidents accounted for 52.8% of the accidents, recreation accidents for 12.7% and other accidents for 33.6%. The annual incidence of one accident or more, for all types of accidents combined, was 12.9%, that for two or more accidents 2.3%. The rate of SPT and recreation accidents decreased strongly with age. SPT accidents were more frequent in girls, the other accidents more frequent in boys. Among the SPT accidents, 69.2% occurred under training conditions and 33.7% were caused by another person. Causes mentioned by the victims were: carelessness (26.0%), clumsiness (17.5%), misappreciation of risk (13.8%), tiredness (9.5%), nervous irritation (8.6%), rowdyism (6.0%), disrespect of the teacher's instructions (6.0%). The lesions were: contusions (50.7%), wounds (18.7%), tendinitis (11.7%), wrenches (9.2%), others (7.3%). They differed between age groups, sex, and category of sports. Localizations were mainly: fingers (27.4%), other localizations of the upper limb (20.1%), head (20.6%). A physician was consulted for 19.5% of the accidents and hospitalization followed 2.7%. Absence from school and exemption from SPT were frequent (11.4% and 16.3% respectively). CONCLUSION: The results could be used to inform adolescents so they and their families could become more aware of the risk of school accidents. Prevention should mainly focus on the younger children. An effort must be made regarding risk assessment in order to help the pupils become more careful and responsible during their sports activities. The choice of these activities and the materials used should be made more suitable for adolescents.

Accidents↗
PubMed2000

Information processing deficits in relatives of manic depressive patients.

BACKGROUND: The importance of genetic factors in the aetiology of manic-depressive illness (MDI) has been repeatedly confirmed and indicators of vulnerability to the illness in families with affective disorders are needed. Abnormal event-related potentials (ERP) may be markers of genetic vulnerability to mental illness. Long latency and low amplitude of P300 have consistently been reported in schizophrenic patients and their relatives. A few studies have also shown P300 deficits in MDI patients, but no ERP study has been performed on their relatives. METHODS: ERPs were recorded during an auditory oddball task in 19 relatives belonging to families with two or more bipolar patients and in controls with no familial or personal history of affective disorders. The relatives were selected as having no affective disorders on a lifetime basis, but eight had an anxiety disorder. RESULTS: In all relatives, a lower P300 amplitude and a longer P300 latency was found, with much longer reaction time and post-N200 duration till button-press than controls. A lack of P300 amplitude dominance in the right hemisphere was also found in relatives in comparison with controls. There also appeared to be a frontal predominance of ERP abnormalities in relatives. CONCLUSION: We report the first evidence of deficits in reaction time and in P300 amplitude and latency, and a lack of P300 right-sided dominance, in relatives of manic-depressive patients. This pattern may constitute an endophenotypic marker of manic-depressive disorder.

Adult↗
PubMed2000

Focused attention in anhedonia: a P3 study.

Attentional and information processing impairments have been evidenced in nonclinical anhedonic subjects. However, the extent of attentional deficit has not been determined. We studied focused attention, the ability to reject irrelevant or distracting messages, in anhedonic nonclinical subjects. The event-related potentials and behavioral performances of anhedonic subjects were compared with those of control subjects during the Eriksen focused attention task (C.W. Eriksen & B.A. Eriksen, 1974); the task combined one compatible and one incompatible condition, the latter causing an interference. Anhedonic subjects exhibited a smaller P300 and slower reaction times than control subjects. Varying task conditions had different effects on anhedonic subjects and controls, suggesting that anhedonic subjects may have developed a conservative response strategy. In view of previous works, these results suggest that attentional impairment is not ascribed to specific processes, but may involve a more global deficit, that is, a resource allocation deficit.

Adolescent↗
PubMed1999

Frontal reactivity and sensation seeking an ERP study in skydivers.

1. In the line of Zuckerman's studies on sensation seeking and optimal level of arousal, the authors hypothesized that high sensation seeking might be used to compensate for anhedonia due to basal arousal deficit. A population of interest was found with parachutists practicing skydiving, generally described as very high sensation seekers. 2. After clinical assessment of emotional and affective components, amplitudes of the frontal P3 of the ERP were used as indices of arousal. 3. Skydivers presented more negative symptoms (anhedonia and blunted-affect) than controls. This was observed in isolation from any depressive episode, which would suggest the presence of emotional deficit as a trait. As expected, skydivers presented more sensation seeking than controls. These two results taken together could indicate that sensation seeking is an adaptive reaction to anhedonia. 4. ERP results showed that frontal P3 amplitudes were larger in skydivers than in controls, whereas in a previous study we showed the opposite in depressed patients with a similar emotional deficit. This could indicate that the frontal P3 amplitude does not reflect the emotional deficit per se. We suggest that it rather reflects the capacity to use some behaviors which improve automatic attentional processes in order to obtain arousing stimulation that could counterbalance the emotional deficit. Depressions with emotional deficit might be due to the lack of such a capacity.

Adult↗
PubMed1998

Transplantation for acute hepatic failure in children.

BACKGROUND/PURPOSE: Acute liver failure in the pediatric population is a rare but highly lethal health problem. Sometimes it is difficult to predict who will benefit from liver transplantation. The authors report on their experience in the past 8 years at a pediatric transplant center. METHODS: A retrospective chart review was performed on all children referred to the liver transplant (TX) service with the diagnosis of acute hepatocellular dysfunction (AHD) from 1988 to 1996. Presentation, chemistries, and clinical course were evaluated. Statistical analysis was performed using analysis of variance. RESULTS: Twenty-six children underwent evaluation. Seventeen patients fulfilled the criteria for fulminant hepatic failure (FHF). Eleven patients recovered without TX, 14 received a TX, and one died awaiting TX. Of those that received a TX, four died in the early postoperative period and 10 survived (mean follow-up of 4.2 years). There was a wide range in most laboratory values. Serum bilirubin levels, ammonia levels, and coagulation parameters, however, reached statistical significance in patients requiring transplant. The most consistent discriminators of need for transplantation and outcome were neurological findings and multisystem organ failure. Children who recovered without TX had no seizures and minimal encephalopathy. Of the 15 children who were recommended for TX, six had seizures and all had encephalopathy, 12 having grade III or IV. All five nonsurvivors had respiratory failure early in their clinical course, and four of five nonsurvivors also had renal failure. CONCLUSIONS: There is significant overlap in the presentation and laboratory findings of children who present with AHD or FHF. Neurological status was an important discriminator of need for transplantation. Patients who presented with multisystem organ failure, including renal failure and respiratory failure, had 100% mortality rate despite liver transplantation.

Analysis of Variance↗
PubMed1998

Results of transplantation for acute and chronic hepatic allograft rejection.

BACKGROUND/PURPOSE: Transplantation for rejection is a requirement in liver transplant recipients when allograft failure is imminent. The authors evaluated the outcome of these children and their allografts. METHODS: The medical records of 129 children who received a liver transplant were reviewed retrospectively. Twelve children required transplantation for biopsy-proven rejection--10 chronic and two acute. Overall patient and graft survival were compared with children receiving primary liver transplants. The current allograft function of the patients undergoing transplants was also reviewed. Statistical significance was determined by Fisher's Exact test. RESULTS: Twelve children received at least one retransplant for biopsy-proven rejection. Graft survival at 1 year was 58% (v 79% for primary transplants) and patient survival was 83% (vs 89%). Two allografts were lost because of primary allograft nonfunction. Three additional allografts were lost-two to recurrent rejection and one to hepatic artery thrombosis. Two patients who lost a second transplant to rejection required a total of seven transplants to treat rejection. Two children died, one of primary nonfunction and one of adenovirus pneumonia. The 10 surviving patients all have excellent graft function (total bilirubin, 0.74 +/- 0.38, aspartate aminotransferase, 40 +/- 22). CONCLUSION: These data suggest that transplantation for rejection can be accomplished safely with a patient survival rate comparable to primary liver transplantation; however, graft loss is excessive and underscores the need for more adequate immunosuppression.

Adolescent↗
PubMed1997

Reduced cyclosporine absorption preceded acute allograft rejection in a child with a liver transplant.

This case report correlates impaired cyclosporine absorption from the traditional oral formulation in a 9-year-old liver transplant recipient with subsequent acute allograft rejection. Although impaired absorption in this patient was documented by cyclosporine pharmacokinetic profiling (steady-state area under the cyclosporine concentration-time curve or AUC), no indication was evident from the pre-dose cyclosporine trough level, which was within the typical target range of blood concentrations. However, when the subject received the microemulsion formulation of cyclosporine the AUC value reflected an adequate absorption pattern. We recommend that if malabsorption is suspected in the de novo pediatric liver transplant patient, then single-sample pre-dose trough cyclosporine levels should not be relied on as an indicator of sufficient immunosuppression and that a limited sampling strategy be used to confirm or rule out impaired absorption.

Absorption↗
PubMed1997

Split liver transplantation benefits the recipient of the 'leftover liver'.

The division of a single hepatic allograft to create two reduced-size grafts has been reported with decreased graft survival (50%) resulting in decreased enthusiasm for this approach. The authors reviewed their experience with 12 recipients of this procedure to evaluate the outcome of the children electively undergoing transplant with the "leftover liver." A retrospective review of six pairs of children receiving part of one hepatic allograft included donor anatomy, recipient operation, and allograft and patient outcomes. Recipient pairs were selected according to blood type compatibility, medical priority, and size restrictions of the larger right lobe and the smaller left lateral segment. Patient and graft survival were compared with elective and urgent patients undergoing whole or reduced-size transplants. Six donors weighed 71.8 +/- 17.4 kg and were 22.6 +/- 11.0 years of age. Recipients of the right lobe were 11.8 +/- 4.2 years of age and weighed 41.9 +/- 14 kg. Recipients of the left lateral segment were 1.81 +/- 1.1 years of age and weighed 9.85 +/- 1.82 kg. Six patients were initially offered the donor allograft because of their hospitalization, critical illness or waiting time. Six additional patients electively underwent transplantation with the leftover liver. Donor organs were screened for normal arterial anatomy. Division of the allograft was performed on the back table in the falciform groove. Generally the left lateral segment graft received the major portion of the hepatic artery and the right lobe the major portion of the portal vein. Five of six (83%) elective patients, two receiving the right lobe and three receiving the left lateral segment had prompt recovery and left the hospital without surgical complication. One recipient of a right lobe transplant died from primary allograft nonfunction. These results are not different from the outcomes of all elective patients who underwent transplantation with whole or reduced-sized transplants in the same program. The authors conclude that split liver transplantation benefits the stable patient who electively receives the liver leftover after reducing the size of a large donor liver for a critically ill child.

Child↗
PubMed1996

Heterogeneity of information-processing alterations according to dimensions of depression: an event-related potentials study.

To identify alterations in elementary cognitive operations according to dimensions of depression, two stages of information processing, namely the response choice and the motor preparation stages, were explored using an event-related potential paradigm in two subgroups of depressed patients (retarded and blunted affect versus anxious-agitated and impulsive) compared to controls. Two results are common to all depressed patients: a slow encoding of stimuli (P1 wave) and a prolonged processing of stimulus-response compatibility (after P3b). This is compensated by a global velocity increase in stimulus evaluation or decision making (P3b) in anxious-agitated patients or, on the contrary, cumulated with its velocity decrease in retarded-blunted-affect patients. Such results could provide an explanation for the massive retardation observed in blunted-affect patients, contrary to anxious-agitated patients, whose normal reaction times may come from a very high energetical involvement at the P3b level. Results as a whole suggest that impairments in blunted-affect patients concern effort mechanisms, whereas those in anxious-agitated patients concern perceptual processes.

Adult↗
PubMed1996

Cognitive and emotional deficits in early stages of HIV infection: an event-related potentials study.

1. In order to inventory different Event-Related Potentials (ERP) modifications in HIV-infection the authors have evaluated 23 HIV-positive subjects and 12 HIV-negative subjects. ERP were recorded during an auditory oddball task. 2. Electrophysiological results showed that the latency of the N100 component of the ERP was significantly increased in HIV-positive subjects compared to the HIV-negative subjects. The latency of the N200 component of the ERP showed a similar tendency which just failed to reach significance when considering HIV-positive subjects vs HIV negative subjects. This result was in agreement with the literature which reported increased latencies in HIV infection. 3. Considering all subjects the authors have observed a correlation between the amplitude of the P300 and the emotional deficit. This correlation was stronger in subjects who presented an emotional deficit and was independent of any other psychopathological symptom. 4. The use of ERP appeared to be a sensitive technique to detect subclinical manifestations in HIV asymptomatic subjects and therefore would help to identify subjects at higher risk for developing cognitive impairments.

Adult↗
PubMed1995

Absorption characteristics of a microemulsion formulation of cyclosporine in de novo pediatric liver transplant recipients.

In pediatric liver transplant recipients, oral cyclosporine (CsA) therapy may be complicated by impaired or delayed absorption during the initial weeks posttransplant. Neoral (NL) is a microemulsion preconcentrate formulation of CsA expected to increase the rate and extent of absorption of CsA and have less pharmacokinetic variability. The absolute bioavailability (F) of CsA from NL was compared with that of the currently marketed Sandimmune (SM) formulation in a double-blind, crossover study conducted in 9 pediatric liver transplant recipients (age 6 months to 11 years) between 8 and 20 days posttransplant. After determination of CsA pharmacokinetics for a steady-state intravenous dose, patients were randomized to receive a single oral dose of NL or SM in period I and the alternative formulation in period II. Clearance (Clt) and volume of distribution (Vss) values (mean +/- s.d.) calculated from the i.v. dose were similar to that previously reported for pediatric patients (Clt = 12.0 +/- 1.3 ml/min/kg; Vss = 2.2 +/- 0.2 L/kg). Mean F (+/- SD) for NL was significantly higher than SM (NL = 37.6 +/- 14.6%; SM = 24.7 +/- 8.0%; P = 0.05). Although not reaching statistical significance, the observed maximum blood concentration (Cmax) was higher, and the time to Cmax (Tmax) was shorter for NL in 8 or 9 patients. There were no significant correlations between age and any pharmacokinetic parameter for the group as a whole--however, there were statistically significant correlations between age and F for NL (r = 0.87; P = 0.02), and for age and Vss (r = 0.91; P = 0.01) for the 6 patients aged 2 years or less. In this pediatric liver transplant population, Neoral demonstrated improved absorption (% increase in F) compared to Sandimmune. In liver transplant recipients aged 2 years or less, absorption of Neoral may be a function of age and/or bowel length.

Administration, Oral↗
PubMed1994

Loss of control of pre-motor activation in anxious agitated and impulsive depressives. A clinical and ERP study.

1. Current research uses a variety of traditional validation methods in order to test the clinical expression of biological models in psychiatry. The application of these methods has resulted in a paradoxical situation which requires the definition of new objectives in biological and pharmacoclinical research: the biological specificity of new psychotropic drugs does not assume any congruence between their pharmacological and their therapeutic effects, but raises the question of the relationship between biological systems and clinical symptomatology. The dimensional description of psychopathological disorders may be more appropriate to biological studies in psychiatry. 2. A study was undertaken on a population of twenty-one in-patients fulfilling the DSM III-R criteria for major depressive episode. They were divided into two groups on the basis of contrasting clinical dimensions: anxious-agitation and impulsiveness versus retardation and affective blunting. 3. Significant clinical differences between the two groups on mood profiles were echoed by contrasts in event-related potentials during a go-nogo task: only anxious agitated and impulsive patients developed an abnormal cortical activity, as measured by contingent negative variation (CNV), in the nogo condition. 4. This paper suggests how a paradigm with control of motor action leads to specify premotor activation abnormalities in the agitated impulsive depression subtype.

Adult↗
PubMed1991

[Pseudarthrosis of the humeral shaft. Apropos of 58 cases].

We report 58 cases of humeral shaft non union following 28 times an orthopaedic treatment where persisted a space between the two fragments and 30 times an osteosynthesis but only 6 where satisfying. The sery contains 2 infected non union, dried in several months and 3 pseudarthrosis we did not operate because they were not inconvenienced. Among the 53 aseptic pseudoarthrosis the union has been to obtained after one operation for 42, two operations for 6 and three operations for 5. We analyse the consecutive mistakes having brought to the failures. We confirm that only an osteosynthesis not sufficient and that an associate graft is necessary. It could be an osteoperiosteum decortication, a spongious graft or a tibial graft (this last one is more safe but reserved to the iterative cases of the one with a big defect). The long evolution (more than a year for half at the cases) explains the fragment repercussions on shoulder or elbow.

Adolescent↗
PubMed1989

[Anhedonia in psychiatry: a review].

Anhedonia, the loss of the capacity of feeling pleasure, was first introduced at the end of the last century by a French psychologist, Ribot, and has been the object of much research, essentially in English, for the last decades, in schizophrenia, in depression, in schizoid disorders. After considering the problems of quantitative evaluation, we review the literature and conclude that anhedonia appears to be a multi-morphological symptom and the are probably several types of anhedonia, which shows the necessity of developing more specific reliable evaluation instruments and of diversifying the approaches. We show the utility, in particular, of a psychophysiological approach using endogenous Evoked Potentials. Then several research directions in psychiatry are discussed: what place has anhedonia in the negative form of schizophrenia? Does anhedonia constitute a specific marker of certain endogenous depressions? Does it constitute a personality trait that predisposes to morbidity?

Affective Symptoms↗