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Biomedical subjects

P Devos

Publications and source records attributed to P Devos.

At least 19 recordsLinked to original sources

Directed forgetting in PTSD: a comparative study versus normal controls.

The most characteristic feature of Post-Traumatic Stress Disorder (PTSD) is the reexperiencing syndrome. The patient's memory seems to be fixed on the traumatic event, which may be due to disturbance of the autobiographic memory. To retrieve memories, others have to be inhibited. These inhibition mechanisms have been studied using the Directed Forgetting Paradigm, which measures the capacity to forget recently processed information and to retain the relevant information. Our hypothesis is that during PTSD, the memory is saturated with traumatic memories, so that the patients are no longer able to use the inhibitory processes. Therefore, during a Directed Forgetting Task (DFT) in which words "to remember" and words "to forget" are given, PTSD patients cannot inhibit the words "to forget", and so recall more words than the controls. We studied 30 patients with PTSD and compared them with 30 healthy controls, using DFT. The results show that the patients remembered significantly fewer words overall, and fewer of the words "to remember" than the controls, both for immediate and final recall. Our results are in favor of a reduction in directed forgetting in patients suffering from PTSD, resulting in difficulty in inhibiting irrelevant information from the overall information. There seems to be a deficit in the inhibitory processes in the memory in PTSD.

Adult↗

[Feeding practices in infants: a 6-month prospective cohort study].

UNLABELLED: The aims of this work were to assess timing of complementary feeding in infants and to precise the underlying factors that may cause inappropriate complementary feeding. PATIENTS AND METHODS: A cohort of 167 newborns, born in the same maternity ward during a 6 week-period, was prospectively analyzed. Only healthy neonates were included in the study. A phone questionnaire was filled at 4 and 6 months of age to evaluate modality of complementary feeding. Multivariate analysis (segmentation tree, analyse by multiple correspondence) was used to study factors associated with inappropriate diversification. RESULTS: Out of the 167 neonates included in the study, 132 mothers could be contacted at 4 months and 116 at 6 months of age. Sixty-seven per cent of mothers started breast feeding at birth. Among these, 33% still breastfed -at least partially- at 4 months and 17% at 6 months. Fifty-two percent of mothers started complementary feeding before 4 months, and 24% of infants received gluten at 4 months of age. Multi-gravida mothers, mothers aged more than 35 years old and mothers who gave infant or follow-up formulae before 4 months, started complementary feeding significantly earlier (P<0.05). Infants who were formula fed received more frequently complementary feeding before the age of 4 months than breast fed infants (57% vs 33%, P<0.05). CONCLUSION: Our study showed that half of infants were introduced solid food too early and allowed to identify a population at risk that could benefit from nutritional intervention programs.

Adult↗

Hospital-acquired pneumonia in critically ill patients: factors associated with episodes due to imipenem-resistant organisms.

BACKGROUND: Inadequate initial antimicrobial therapy represents one of the factors associated with mortality of patients suffering from hospital-acquired pneumonia. According to its wide antimicrobial spectrum, imipenem belongs to the usual antibiotics proposed by current guidelines for such a therapy. However, major changes in the antibiotic susceptibility patterns of bacteria in the intensive care unit (ICU) have occurred. Our goal was to determine the incidence of hospital-acquired pneumonia (HAP) due to imipenem-resistant organism(s) in our ICU and to identify factors associated with such a resistance. PATIENTS AND METHODS: From January 1994 to December 2001, all consecutive patients admitted to our ICU for HAP or exhibiting HAP during their ICU stay were included in an observational cohort. Patients with a bacteriologically documented HAP were studied. For each causative pathogen, imipenem susceptibility was routinely determined. Patients with an HAP episode due to at least one imipenem-resistant causative organism were compared with patients who developed HAP in which all incriminated pathogens were imipenem susceptible. RESULTS: 235 patients were included in our observational cohort. Among them, 168 had an HAP episode with a bacteriologically proven infection. In 42 patients (25%), at least one causative organism was resistant to imipenem. The 44 imipenem-resistant organisms were Staphylococcus aureus (n = 15), Pseudomonas aeruginosa (n = 14), Stenotrophomonas maltophilia (n = 13), and Acinetobacter baumannii (n = 2). Multivariate analysis identified four significant independent factors associated with resistance of causative organism(s) to imipenem: prior use of a fluoroquinolone (AOR = 3.9; 95% CI: 1.8 to 8.8; p < 0.0001), prior use of an aminoglycoside (AOR = 2.6; CI: 1.2 to 5.9; p = 0.02), use of invasive blood pressure monitoring (AOR = 2.7; CI: 1.0 to 7.0; p = 0.04) and bilateral chest X-ray involvement (AOR = 2.6; CI: 1.1 to 5.8; p = 0.02). CONCLUSION: Factors associated with potential inadequacy of imipenem used as the single antibiotic for initial empiric treatment for HAP were identified. When they are present, imipenem should be either combined with antibiotics such as vancomycin and ciprofloxacin or replaced with another broad-spectrum antimicrobial regimen.

Acinetobacter baumannii↗

Diagnostic and prognostic values of admission procalcitonin levels in community-acquired pneumonia in an intensive care unit.

BACKGROUND: Measurement of procalcitonin (PCT) has been studied for several years in infectious diseases. Some studies have focused on community-acquired pneumonia (CAP) but only one was conducted in critically ill patients hospitalized in an intensive care unit (ICU). PATIENTS AND METHODS: To determine the diagnostic and prognostic role of PCT in patients admitted in an intensive care unit for severe CAP, 110 patients hospitalized in our unit were prospectively studied. Within 48 hours following ICU admission, PCT serum level was measured with a quantitative method above a threshold value of 0.5 ng/ml. RESULTS: Initially focusing on the diagnostic value of PCT, 20% of the patients had a serum PCT level <0.5 ng/ml, 30% between 0.5 ng/ml and 2 ng/ml, and 50%>/=2 ng/ml. Serum PCT level was higher in microbiologically documented CAP (median=4.9 ng/ml vs 1.5 ng/ml if no bacteria were found; p=0.001), but was not predictive of any specific bacterial agent. Concerning the prognostic value, the serum PCT level was higher for bacteremic patients and/or septic shock patients (4.9 ng/ml vs 1.5 ng/ml; p=0.0003). Moreover, PCT levels were increased in patients who developed, during their ICU stay, infection-related complications (septic shock, multiorgan dysfunction, acute respiratory distress syndrome and disseminated intravascular coagulation). Finally, the initial PCT level was significantly higher in patients who died during the ICU stay (5.6 ng/ml vs 1.5 ng/ml; p<0.0001). Such a relationship was not found with C-reactive protein (CRP). CONCLUSION: In ICU patients admitted for severe CAP, initial PCT values could be an interesting predictor for complications and mortality.

Adult↗

Hyper-osmoregulatory capacity of the Chinese mitten crab (Eriocheir sinensis) exposed to cadmium; acclimation during chronic exposure.

The aim of this study was to evaluate the effects of waterborne cadmium on hyper-osmoregulatory capacity of the Chinese mitten crab Eriocheir sinensis acclimated to freshwater. For this purpose, crabs were submitted to acute (0.5 mg Cd L(-1) for 1, 2 or 3 days), chronic (10 or 50 microg Cd L(-1) for 30 days) or chronic, immediately followed by acute, exposure. While no effect was observed after 1 or 2 days, hemolymph osmolality, Na(+) and Cl(-) concentrations were significantly reduced after 3 days of acute exposure. Under this latter condition, the respiratory anterior gill ultrastructure, Na(+)/K(+)-ATPase and cytochrome c oxidase activities were significantly impaired. In contrast, the osmoregulatory posterior gill was unaffected for all treatments. As a consequence, we suggest that the observed hyper-osmoregulatory capacity impairment is the result of increased dissipative flow of ions and/or water through anterior gills. In contrast to acute exposure, chronic exposure did not induce any observable effect. However, crabs submitted to a known deleterious acute condition (0.5 mg Cd L(-1) for 3 days) directly after chronic exposure to 50 microg Cd L(-1) for 30 days showed normal hyper-osmoregulatory capacity with no change in gill Na(+)/K(+)-ATPase activity, and only little disturbance of anterior gill ultrastructure. These results demonstrate that a chronic cadmium exposure can induce acclimation mechanisms related to osmoregulation in this euryhaline decapod crustacean.

Acclimatization↗

Tissue-specific cadmium accumulation and metallothionein-like protein levels during acclimation process in the Chinese crab Eriocheir sinensis.

Aquatic organisms chronically exposed to cadmium can increase their resistance to a subsequent elevated exposure. In order to investigate mechanisms involved in acclimation process in the Chinese crab Eriocheir sinensis, we compared Cd level as well as metallothionein-like protein (MTLP) content in different tissues after direct acute exposure (i.e. 500 microg Cd L(-1) for 3 days), and after acute following chronic (i.e. 10 or 50 microg Cd L(-1) for 30 days) exposure. Cadmium accumulation occurred in the following order: anterior gill>hepatopancreas>posterior gill>carapace>hemolymph>muscle. As high concentrations as 188 microg Cd g(-1) w.w. were reported in anterior gills and seem to reach a saturation level. In these gills, the highest MTLP induction was observed after a direct acute exposure, for which a correlation with Cd content occurred. However, the Cd-binding potential by MTLPs was exceeded for any exposure condition. In hepatopancreas, the highest Cd level was reported for crabs acclimated during 30 days to 50 microg Cd L(-1) before challenging with an acute exposure. Moreover, we showed that MTLPs were induced during the acclimation process. In this organ, MTLPs are theoretically sufficient to bind all Cd. These results suggest that during a chronic exposure to 50 microg Cd L(-1), Chinese crabs acquire the capacity to hold more cadmium in hepatopancreas where it can be sequestrated by MTLPs. On the contrary, MTLP induction seems to be a rapid response to acute exposure in anterior gill, but is not sufficient to sequester all Cd. Other sequestration and/or detoxification mechanisms must take place in anterior gill to cope with high Cd levels.

Acclimatization↗

[An assessment of stress in adolescent inpatients].

UNLABELLED: Hospitalisation often remains stressful for adolescents. Therefore the improvement of life conditions and management of poorly adolescents during their hospital stay grows into an important concern in the medical staff. However, there is a lack of standardized instruments for an objective and reproducible assessment of problems related to this subject. The Hospital Stress Rating Scale (HSRS), validated in hospitalized adult patients, seems to be an interesting tool allowing an assessment of the level of stress and to specify the stressful factors. SUBJECTS AND METHODS: During ten months, 107 adolescent inpatients, 39 males and 68 females, aged on average 13.5 +/-1.5 years, were included in the study. In addition to the HSRS, in a version adapted for adolescents, two other self-report questionnaires were used: the Toulouse Stress Rating Scale (TSRS), which is a rating scale validated to assess the level of stress and to identify the clinical manifestations of stress in adolescents, and the Toulouse Coping Rating Scale (TCRS), which is a rating scale validated to assess the coping style of adolescents in stressful situations. The sociodemographic and clinical characteristics of the studied subjects were collected by a standardized questionnaire. RESULTS: A significant correlation was found between the HSRS mean total score and the TSRS mean total score. The HSRS item by item analysis showed that the nature of the stressors varied according to the clinical characteristics of the subjects. Lastly, the coping style was found having a significant influence on the level of stress reported by the subjects. CONCLUSION: Even if they were obtained in a relatively small sample, these results show that the HSRS is a useful tool to assess the stress reported by the hospitalized adolescents. Such an instrument may be useful to plan aid and preventive strategies and to assess their impact in hospitalized adolescents.

Adolescent↗

Statistical tools for clinical gait analysis.

Gait analysis studies involve continuous curves of data measured over a gait cycle. Curve analysis and interpretation require adequate statistical methods. Three principal problems may be encountered in clinical practice: (i) the reliability of gait curves for a given patient, (ii) classifying a new subject as belonging to a given population or not and (iii) comparison of two populations (independent or paired). This paper presents three statistical tools for solving these problems: (i) intra-class correlation coefficients, (ii) confidence bands for a population (iii) a combination of analysis of variance and confidence bands for the difference between the means and shows how they can be used in clinical practice.

Adult↗

Hip-flexed postures do not affect local anaesthetic spread following induction of epidural analgesia for labour.

Hip-flexed postures enlarging the pelvic diameter are used to improve the obstetric course of labour. Although most investigations show that lateral and sitting positions do not affect the spread of epidural analgesia, the effect of recently introduced hip-flexed postures has yet to be confirmed. This prospective randomised study included 93 parturients. Ropivacaine 0.1% 12 mL plus sufentanil 0.5 micrograms/mL was administered epidurally over a period of 6 min in one of four postures: sitting, right hip-flexed left lateral position, left hip-flexed right lateral position and supine 30 degrees lateral tilt as a control group. Left and right cephalad and sacral epidural spread were measured every 2 min over a period of 30 min. Pain relief, motor blockade and maternal and fetal side effects were noted. The total epidural spread was 15+/-0.3 dermatomes and the upper level of thermo-algesic blockade T7-T8 (range T3 to T10) in all groups. There were no differences between groups in left or right total spread or upper level of epidural blockade, time to maximal block or pain relief. There was no motor block nor any maternal or fetal side effects. The power of the study (1 - beta) was 93%. We conclude that, for the three hip-flexed postures tested, position does not influence local anaesthetic spread or symmetry of thermo-algesic blockade after induction of obstetric epidural analgesia.

Adult↗

Uptake of cadmium through isolated perfused gills of the Chinese mitten crab, Eriocheir sinensis.

Using the perfusion method, we compared cadmium accumulation and influx across the gills of the euryhaline Chinese mitten crab Eriocheir sinensis, exposed to 4.8 microM cadmium in the incubation medium (OUT). Cadmium influx was not observed across posterior gills while it ranged from 0.15 to 6.82 nmol Cd g(-1) gill w.w. h(-1) across anterior ones. For these respiratory gills, a strong increase (40 times) was observed when calcium was removed in both incubation and perfusion media while the lack of sodium in the perfusion medium resulted in a 46 times decrease. For crabs acclimated 15 days to artificial seawater, cadmium influx across anterior gills showed a 21 times decrease when compared with freshwater acclimated ones. On the other hand, after 3 h of perfusion, we detected cadmium accumulation in both types of gills, ranging from 3.8 to 68 nmol Cd g(-1) gill w.w. in anterior gills and from 2.1 to 39 nmol Cd g(-1) gill w.w. in posterior ones. Such accumulations represent between 61.3 and 100% of the total uptake of cadmium through the gills. From these results, we suggest that cadmium can penetrate more easily into the hemolymph space through the 'respiratory' type epithelium present in the anterior gills but absent in the posterior ones. This metal uptake is likely to occur at least in part through the same pathways as calcium. On the contrary, cadmium seems to be sequestered inside the posterior gills, perhaps in the cuticle of the salt-transporting type epithelium.

Animals↗

Risk factors of early and late complications in patients undergoing endovascular aneurysm repair.

OBJECTIVES: to identify pre-operative factors that could predict complications following from transluminal repair of abdominal aortic aneurysms (AAA). METHODS: during a 5-year period, 96 consecutive patients underwent elective endovascular treatment of a AAA. In all patients, helical CT and/or Magnetic Resonance Imaging (MRI), and plain abdominal roentgenogram were performed at 1, 3, 6, 12, 18, and 24 months and yearly thereafter. Angiography was performed systematically 1 year after the stent-graft implantation, or earlier if helical CT or MRI diagnosed an increase in the maximal transverse diameter or a high flow endoleak. RESULTS: early (<30 days) morbidity (12%) was significantly increased by pre-operative renal insufficiency (p < 0.01). Early mortality (2%) correlated with ASA score (p = 0.01). Median follow-up was 27 months (range 3-66). Mortality (12%) during follow-up was correlated to the pre-operative coronary status (p = 0.01). A type I endoleak was diagnosed in 18 patients (19%). Common iliac artery diameter was correlated with the presence of type I endoleak (p < 0.001). A type II endoleak was diagnosed in 47 (49%) patients. The diagnostic of type II endoleak was significantly increased (p = 0.001) in patients with pre-operative patent IMA associated with more than four patent lumbar arteries. The anatomic characteristics of the aneurysm were correlated to the additional endovascular procedures during stentgraft implantation (p = 0.01), and to the implantation of a complementary iliac limb extension during follow-up (p = 0.01). CONCLUSIONS: the risk factors determined by this statistical analysis could help surgeons to select more accurately patients suitable for endovascular treatment.

Aged↗

A preprocessing method for improving data mining techniques. Application to a large medical diabetes database.

The Knowledge Discovery in Databases (KDD) methodology seems to be attractive on the analyze of large clinical databases. In the KDD process, the preprocessing step (data cleaning and handling of missing values) is paramount since it conditions the quality of the results obtained by data mining procedures and represents about 80% of the whole project time. The aims of the present study were to analyze this step and provide tools to handle inconsistent data and missing values. We have broken down the process into 3 main stages: data cleaning--explanatory study of missing values--choice of the procedure used for handling missing values. The data cleaning stage was based on a system of logical rules to correct mistakes and on cluster analysis to discard the poorly filled files. The missing-data mechanism was analyzed by means of multivariate statistical procedures. Two methods to deal with missing values were compared: imputation by the most common value (mode) and imputation using decision trees. This study was performed on a large medical diabetes database (23,601 patients) including numerous missing values. A system of logical rules allowed to correct mistakes on essential parameters (for example, the type of diabetes). Cluster analysis allowed to identify 10% of poorly filled files. After multivariate analysis, the missing-data mechanism could be considered as random. For variables with low number of missing values (< 10%) and categories (< 4), imputation using decision trees provided better results than imputation by mode.

Data Interpretation, Statistical↗

SIGAPS: a prototype of bibliographic tool for medical research evaluation.

Evaluation of research activity is extremely important but remains a complex domain. There's no standardized methods and evaluation is often based on the scientific publications. It is easy to identify, for a researcher, all the publications realized over a given period of time. At the level of an important establishment like an University Hospital, with about 500 researchers, this sort of inventory is very difficult to realize: we have to list the researchers, to list their publications, to determine the quality of articles produced, to store retrieved data and to calculate summary statistics. We have developed a full-Web prototype, using free software which, for a given researchers' list, interrogates the Pubmed server, downloads the found references and stores them in a local database. They are then enriched with local data which allow the realization of more or less complex analyses, the automatic production of reports, or keyword search. This tool is very easy to use, allowing for immediate analysis of publications of a researcher or a research team. This tool will allow to identify those active teams to be maintained or emergent teams to be supported. It will also allow to compare candidate profiles for appointments to research posts.

Biomedical Research↗

Effects of atrazine on osmoregulation in the Chinese mitten crab, Eriocheir sinensis.

This study integrates results from acute contamination with atrazine of isolated perfused gills, and from in vivo chronic contamination of euryhaline Chinese mitten crabs, Eriocheir sinensis, acclimated to freshwater. Atrazine 1 mg/l in contact with the basolateral membrane (IN) increases the transepithelial potential difference (TEP) from -20.8 +/- 4.9 to -29.7 +/- 3.8 mV in isolated perfused posterior gills (P < 0.01). This effect is only partially explained by a modification of Na(+) and Cl(-) active influxes. No TEP modification is detected when atrazine is added (OUT) indicating that molecular mechanisms located on the basolateral membrane are likely to be the only ones affected. Another explanation would be that cuticular barrier prevents atrazine penetration into the gill. Haemolymph osmolarity, Na(+) and Cl(-) concentrations of crabs living in freshwater contaminated with atrazine 1 mg/l during 14 days are not significantly modified. We conclude that although atrazine can disturb osmoregulatory mechanisms of isolated gills, this pollutant would be of minor importance in affecting osmoregulatory capacities of the Chinese mitten crab in natural conditions.

Animals↗

Hospital-acquired pneumonia: microbiological data and potential adequacy of antimicrobial regimens.

Adequate antimicrobial therapy is a main approach employed to decrease the mortality associated with hospital-acquired pneumonia (HAP). All methods that optimise empirical treatment without increasing antibiotic selective pressure are relevant. Categorisation of patients according to HAP time of onset, severity and risk factors (American Thoracic Society (ATS) classification) or duration of mechanical ventilation and prior antibiotics (Trouillet's classification) are two such methods. The aim of this study was to catagorise patients with HAP according to these classifications and to determine the frequency of resistant pathogens and the most adequate antimicrobial regimens in each group. A total 124 patients with bacteriologically proven HAP were studied. The ATS classification categorised patients by increasing frequency of resistant pathogens from 0-30.3%. The ATS empirical antibiotic recommendations appeared valid but proposed combinations including vancomycin for 72.5% of patients. Trouillet's classification categorised patients into four groups with a frequency of resistant pathogens from 4.9-35.6%. Vancomycin was proposed for 48.5% of patients. The American Thoracic Society classification appears to be more specific than Trouillet's for predicting the absence of resistant causative pathogens in hospital-acquired pneumonia but could lead to a greater use of vancomycin. Stratification combining the two classifications is an interesting alternative.

Aged↗

[Criteria for percutaneous non-closure of interatrial communications of the ostium secundum type by the Amplatzer septal occluder].

The aim of the study is to recognise the criteria preventing the percutaneous closure of an interatrial communication of the ostium secundum type for the Amplatzer septal occluder device. From January 1999 to December 2000, 121 consecutive patients with an average age of 24.8 +/- 19 years affected with an interatrial communication of the ostium secundum type underwent echocardiographic examination with transthoracic Doppler to evaluate the maximal diameter of the communication, the border dimensions, and the length of the interatrial septum; 92.5% of them underwent haemodynamic investigation to evaluate the shunt and the stretched diameter. Comparison of the umbrella group averages with the surgical group was performed by the Student test, and the frequencies by the Chi 2 test. ROC curves were drawn for the numeric parameters. After these 2 examinations, 68 patients underwent an attempt at percutaneous closure with 61 successful (84.7%) and 53 had a surgical closure straight off. The surgical group was younger, with a more significant shunt and a wider communication. The criteria for non-closure apart from abnormal pulmonary venous reflux were: insufficient border (59% of cases), diameter too wide (16%), multiperforate septum (16%) and insufficient septum length (9%). Percutaneous closure could be performed in 2/3 of interatrial communications without abnormal pulmonary venous reflux. Candidates for surgery were younger, with a more significant shunt and a wider diameter. In retrospect 8 patients of the surgical group could have had percutaneous closure and 7 patients of the umbrella group could have been sent straight for surgery.

Adolescent↗

Factor VII, tissue factor pathway inhibitor, and monocyte tissue factor in diabetes mellitus: influence of type of diabetes, obesity index, and age.

Changes of the tissue factor (TF) pathway of blood coagulation have been described in diabetes and could be involved in its vascular complications. In order to evaluate the influence of the type of diabetes and of the obesity index and age on these changes, factor VII coagulant activity, factor VII antigen, activated factor VII, monocyte TF expression, and plasma Tissue Factor Pathway Inhibitor (TFPI) were examined in 18 Type 1 and 16 Type 2 diabetic patients compared to non-diabetic control subjects matched for age, sex, and obesity index (Types 1 and 2 controls, respectively). Multicomplicated patients were excluded. FVIIc, FVIIAg, and FVIIa were higher in Type 2 diabetic patients and controls than in Type 1 diabetic patients and controls (P< .03). However, FVIIc and FVIIAg were lower in diabetic patients than in their matched controls (P< .03). Monocyte expression of TF was not different between Types 1 and 2 diabetic patients and their matched controls except for LPS-stimulated monocyte TF activity which was lower in Type 2 diabetic patients than in Type 2 controls (P< .05). Plasma TFPI was slightly but significantly higher in Type 1 diabetic patients than in Type 1 controls (P= .01) and was correlated to glycemia. However, both in Type 2 diabetic patients and controls, TFPI was higher than in Type 1 controls and was correlated with BMI (P< .0003). These results indicate that in not multicomplicated patients, the increase of FVII and TFPI was highly dependent on obesity index and age rather than on diabetes by itself.

Adult↗