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Biomedical subjects

C Faure

Publications and source records attributed to C Faure.

At least 19 recordsLinked to original sources
PubMed1997

The thickness of cholesterol sulfate-containing membranes depends upon hydration.

The ordering of 30 mol % cholesterol (CH) or cholesterol sulfate (CS) on chain deuterated dimyristoylphosphatidylcholine (DMPC) was investigated by 2H-NMR for different hydrations. It is found that: (i) hydration has merely no influence on chain order (chain length) for DMPC-cholesterol systems, (ii) in CS-containing mixtures chain order (length) is greater at low hydration (DMPC-to-water molar ratio, Ri, of 11.3) than in excess water (Ri approximately 500) and (iii) at low hydration the ordering is about the same for CS or CH-containing systems whereas it is not at high hydration. DMPC-CS bilayer thickness is therefore very sensitive to hydration.

Cholesterol Esters↗
PubMed1997

[Esophageal pH-metry. Evaluation of prescriptions at the Robert-Debré Hospital (Paris)].

OBJECTIVES: To record orders for esophageal pH-metry at the Robert-Debré hospital in Paris and to assess the quality and pertinence on the order. METHODS: A prospective survey of all children who underwent pH-metry during the month of February 1996 was conducted. There were 11 children included in the study. RESULTS: Half of the pH-metries were performed in inpatients and half in outpatients including 18% scheduled directly by the exploration unit. The order did not provide any reason for the exploration in 15% of the cases (42% of those scheduled by the unit). When a reason was explained, the order described the clinical context in 86% of the cases but did not give any information on ongoing treatment in 40%. Clinical indications mentioned respiratory or ear-nose-throat disease in 70% of the cases and regurgitations or vomiting in 42%. Pathological reflux was diagnosed in one-third of the explorations. An anti-reflux treatment was prescribed for half of the patients. In reference to the official prescription guidelines in France (Référence Médicale Opposable, RMO), 72% of the orders were pertinent, 10% were questionable, 10% did not comply to official guidelines, and 8% could not be classified due to lack of information. CONCLUSION: These findings point out that the official guidelines may be of questionable value in the hospital setting.

Adolescent↗
PubMed1997

Determination of DMPC hydration in the L(alpha) and L(beta') phases by 2H solid state NMR of D2O.

The number of water molecules bound to the dimyristoylphosphatidylcholine (DMPC) interface was investigated both in the fluid (L(alpha)) and gel (L(beta')) phases by solid state deuterium NMR of D2O. We determined that each DMPC molecule binds 9.7 +/- 0.5 and less than 4.3 +/- 0.5 D2O in the fluid and gel phases respectively. These results are accounted for by considering the number of DMPC binding sites as well as the molecular organization in each phase.

Calorimetry, Differential Scanning↗
PubMed1997

Pericardial reflection around the venous aspect of the heart.

The authors have studied the pericardial recesses of the venous aspect of the heart. They report 107 anatomical dissections on fresh cadavers with the cardiac cavities artificially filled. Variations in the number of the pulmonary vv., in their diameters and their pericardial segments are reported. The characteristics of the oblique sinus, of the postcaval and pulmonary recesses are also reported. These variations define five types of pericardial morphology. A classification is proposed. These results differ from those in the literature, possibly because the pericardial reflection is delineated in diastolic filling of the cavities. These morphometric data are useful in anatomic instruction, imaging of the mediastinum, and the surgery of malignant tumors and pulmonary transplantation.

Adolescent↗
PubMed1997

A critical appraisal of current management practices for infant regurgitation--recommendations of a working party.

Regurgitation is a common manifestation in infants below the age of 1 year and a frequent reason of counselling of general practitioners and paediatricians. Current management starts with postural and dietary measures, followed by antacids and prokinetics. Recent issues such as an increased risk of sudden infant death in the prone sleeping position and persistent occult gastro-oesophageal reflux in a subset of infants receiving milk thickeners or thickened "anti-regurgitation formula" challenge the established approach. Therefore, the clinical practices for management of infant regurgitation have been critically evaluated with respect to their efficacy, safety and practical implications. The updated recommendations reached by the working party on the management of infant regurgitation contain five phases: (1 A) parental reassurance; (1 B) milk-thickening agents; (2) prokinetics; (3) positional therapy as an adjuvant therapy; (4 A) H2-blockers; (4 B) proton pump inhibitors; (5) surgery.

Antacids↗
PubMed1997

Ultrasonographic assessment of inflammatory bowel disease in children: comparison with ileocolonoscopy.

OBJECTIVES: To determine the feasibility and value of transabdominal ultrasonography of the terminal ileum and colon of children with inflammatory bowel disease (IBD) and to compare the findings with those of ileocolonoscopy. STUDY DESIGN: Thirty-eight patients ranging in age from 4 to 18 years who underwent ileocolonoscopy for management of IBD or for diagnosis were studied prospectively. Twenty-one patients had Crohn disease, nine had ulcerative colitis, and eight served as control subjects. Transabdominal ultrasonography was performed on the day before ileocolonoscopy. Ultrasonographic findings were compared with the results of ileocolonoscopy, used as the reference method. RESULTS: Peristalsis was recorded in all segments of the control subjects; the thickness of the terminal ileum was always less than 2.5 mm, and that of the large bowel, 2 mm or less. In the two patient subgroups, the thickness range of affected ileal and colonic segments was similar, but values were significantly different from those of the control subjects (chi-square test, p <0.0001). The overall sensitivity of the method was 88%, and the specificity, 93%. CONCLUSION: Transabdominal ultrasonography should prove to be a useful clinical and investigational technique, although further studies are needed to assess its value in the treatment of children with IBD.

Adolescent↗
PubMed1997

[Hypertrophic cardiomyopathy complicating a prolonged corticotherapy for hemorrhagic rectocolitis].

BACKGROUND: The cardiac side-effects of corticosteroid therapy are very uncommon. CASE REPORT: A girl with ulcerative colitis developed at the age of 8 years an acute digestive episode despite prednisolone and total parenteral nutrition. The patient was then given intravenous methylprednisolone (2 mg/kg/d). Polypnea appeared 25 days later while blood pressure remained normal. Echocardiography revealed a cardiac hypertrophy associated with a systolic anterior motion of the mitral valve. Cardiac symptoms and echography findings returned to normal after reduction of corticosteroid therapy and its administration via the oral route. CONCLUSION: Hypertrophic cardiomyopathy has been described in preterms treated with dexamethasone for bronchopulmonary dysplasia. It is exceptional in older children under corticosteroid therapy and its mechanism remains unknown.

Cardiomyopathy, Hypertrophic↗
PubMed1997

[Long QT syndrome under cisapride in neonates and infants].

BACKGROUND: Cisapride is frequently used in the newborn and infant for treatment of gastroesophageal reflux. Twisting-spikes have been reported in adults due to overdosage or therapeutic interaction. We report seven cases of QT prolongation in infants treated with cisapride. PATIENTS AND METHODS: Seven children (one full-term, two mature preterms, four preterm babies), aged (mean, range) 41.8 +/- 21 days (14-79) weighing 2.1 +/- 1.1 kg (1.2-4), free from any cardiac abnormality, except one patent ductus arteriosus, have been studied by ECG and Holter monitoring. They received cisapride at a mean dose of 1.31 +/- 0.2 mg/kg/d (between 1 and 1.7 mg/kg/d). RESULTS: The corrected QT (QTc: N < 450 ms) was increased to 486 ms (450-540) with a notched T-wave pattern. No arrhythmia was detected. In five cases, cisapride was stopped and changed to metoclopramide. Cisapride dosage was reduced to 0.8 mg/kg/d in the two others. No other therapeutic modification was done. A control ECG performed 48 hours after therapeutic changes showed a QTc shortening of 74 +/- 18 ms (45-90) and the disappearance of the notches independent of any heart rate changes, leading to normal QTc values: 413 +/- 21 ms (390-440). CONCLUSION: High cisapride dosage in preterm, newborns and infants seems to favor QT prolongation which is reversible when dosage is reduced or drug is stopped. The use of cisapride in combination with other drugs known to increase QT should be done with extreme caution.

Anti-Ulcer Agents↗
PubMed1997

Computer assisted spine surgery.

When inserting screws into a vertebral pedicle, the surgeon usually exposes the back part of the vertebra and uses his or her anatomic knowledge to align the drill in the proper direction. A slight error in direction may result in an important error in the position of the tip of the screw. This is done with no direct visibility of crucial structures (spinal cord, pleura, vessels). Statistical analysis of a series of surgical procedures has shown that 10% to 40% of the screws are not installed correctly. To reduce the risk of complication, a computer assisted method is proposed that enables the surgeon to place a screw at a position preoperatively defined in 3 dimensions using computed tomography images. This allows the surgeon to align a standard surgical drill with the optimal position and direction. The depth of the pilot hole during drilling also is monitored by the system to prevent penetration of the anterior cortex of the vertebral body. Using this procedure, in vitro tests were performed and showed that an accuracy of less than 1 mm can be obtained. Clinical trials were done in 10 patients who suffered severe scoliosis or spondylolisthesis. The trajectory of the holes drilled in L2, L3, L4, and L5 vertebrae were checked for all clinical tests. Postoperative radiographs and computed tomography scans showed that the screws were well inserted in each plane for each pedicle. This technique also can be used to perform osteosynthesis at the thoracic and cervical levels.

Adult↗
PubMed1997

[Chronic external instability of the ankle. Contribution of dynamic radiographies, x-ray computed tomography and x-ray computed tomographic arthrography].

We retrospectively evaluated the anterior talo fibular ligament and the tarsal sinus of 17 patients who had complained of chronic ankle external instability. This study based on both surgery and CT-arthrography findings shows the pathologic or normal aspects of the talo-fibular anterior ligament (normal, lax, fibrosis residue, ruptured). It confirms the good anatomic analysis of the tarsal sinus, in particular the anterior talo-calcaneal interosseous ligament and the search for fibrosis. We underline that capsular distension due to subtalar laxity is not detected with medical imaging. Compared with surgery (all patients), CT arthrography demonstrated the different aspects of the anterior talo fibular ligament injuries (normal, lax, discontinuous).

Adolescent↗
PubMed1996

Evidence for 5-HT1D beta but not 5-HT1D alpha receptor subtype expression in canine large coronary arteries and saphenous vein.

OBJECTIVE: 5-Hydroxytryptamine1D (5-HT1D) receptors are believed to play a major role in the vasoconstriction of vascular smooth muscle in human coronary arteries. However, unequivocal evidence as to which subtype of this receptor (5-HT1D alpha or 5-HT1D beta) is involved in these vasoconstrictory effects is lacking. The aim of this study was to identify in the dog the 5-HT1D receptor subtype encoding mRNAs expressed in several large coronary arteries and in the saphenous vein. METHODS: Degenerate oligonucleotide primers that selectively recognized only mammalian 5-HT1D alpha and 5-HT1D beta receptor sequences were used in RT-PCR experiments to study 5-HT1D receptor subtype expression in endothelium-denuded saphenous vein and large coronary arteries from beagle and alsatian dogs. Resulting PCR products were analysed and identified by Southern blots and sequencing. RESULTS: An identical PCR product whose sequence closely resembles that of the human 5-HT1D beta receptor (98% amino acid identity) was obtained from reverse-transcribed RNA isolated from either saphenous vein or coronary arteries, irrespective of dog race. Absence of 5-HT1D alpha expression was confirmed by Southern blot analysis. Control experiments using canine genomic DNA as template illustrated, nonetheless, that the primers chosen could amplify both 5-HT1D alpha and 5-HT1D beta sequences. CONCLUSION: Using RT-PCR, we isolated from dog vascular smooth muscle a cDNA fragment whose nucleotide sequence would encode a previously-unreported canine homologue of the 5-HT1D beta receptor. We illustrated that this subtype is the only 5-HT1D receptor subtype expressed in dog saphenous vein and large coronary arteries. The implications of these findings are discussed in light of results from functional studies of 5-HT1-like receptor-mediated effects in these canine blood vessels.

Amino Acid Sequence↗
PubMed1996

Pharmacological profile of benzodiazepine site ligands with recombinant GABAA receptor subtypes.

Using [3H]flumazenil as a probe we investigated how benzodiazepine site pharmacology of alpha beta gamma ternary combinations of GABAA receptors can be influenced upon expression of different isoforms of alpha, beta and gamma subunits. The nature of the beta subunit did not alter the pharmacology of this site in that the affinities of alpha 5-containing GABAA receptors for various benzodiazepine modulatory ligands were essentially unchanged upon a comparison of different beta-variant forms (alpha 5 beta 1 gamma 2, alpha 5 beta 2 gamma 2 and alpha 5 beta 3 gamma 2). In contrast, both alpha and gamma variants contributed to notable differences in benzodiazepine site pharmacology. Thus alpha 1 beta 2 gamma 2, alpha 3 beta 2 gamma 2 and alpha 5 beta 2 gamma 2 receptors showed high, intermediate and low affinities for zolpidem, respectively. Exchanging gamma 2 for gamma 3 reduced the affinities of alpha 1 beta 2 gamma and alpha 3 beta 2 gamma receptors for zolpidem by factors of > 150 and > 5.8, respectively. The alpha 1 beta 2 gamma 3, alpha 3 beta 2 gamma 3 and alpha 5 beta 2 gamma 3 receptors exhibited, in contrast, higher affinity for CL218872 than their corresponding gamma 2 receptors. The information on these different recombinant GABAA receptor pharmacological profiles should help in the elucidation of native GABAA receptor subtype diversity.

Animals↗
PubMed1996

[Sleeping position, prevention of sudden death syndrome and gastroesophageal reflux].

Based on results of epidemiological studies, dorsal or lateral sleeping positions are now recommanded in the prevention of sudden infant death syndrome (SIDS). This raises an ethical question about the attitude towards the ventral positioning therapy for gastroesophageal reflux (GOR). The consensus conference considers that the ventral position should only be recommanded in GOR when the benefit appears to outweigh the risk of SIDS that it induces. The conference proposes that for infants with simple uncomplicated reflux, sleeping in the prone position should not be introduced in the first line treatment. Prone positioning should be restricted to complicated cases resistant to dietary and medical measures.

Gastroesophageal Reflux↗
PubMed1996

Comparative effects of cholesterol and cholesterol sulfate on hydration and ordering of dimyristoylphosphatidylcholine membranes.

The comparative effect of cholesterol (CH) versus cholesterol sulfate (CS) on dimyristoylphosphatidylcholine (DMPC) membranes has been investigated by optical microscopy, freeze-fracture electron microscopy, x-ray diffraction, and solid state 2H and 31P nuclear magnetic resonance (NMR). The sulfate analogue extends the lamellar phase domain toward high water contents, and substitution of 30 mol % CH by CS in DMPC lamellae induces the trapping of 30 wt % additional water. The greater swelling of the CS-containing systems is evidenced by determination of lamellar repeat distances at maximal hydration: 147 +/- 4 A and 64 +/- 2 A in the presence of CS and CH, respectively. 2H-NMR of heavy water demonstrates that CS binds approximately 12 more water molecules at the interface than CH whereas NMR of deuterium-labeled DMPC chains reveals that 30 mol % CS orders the membrane as 15 mol % CH at high temperature and disorders much more than CH at low temperatures. The various effects of CS versus CH are discussed by taking into account attractive Van der Waals forces and repulsive steric/electrostatic interactions of the negatively charged sulfate group.

Binding Sites↗
PubMed1996

Resting energy expenditure before and after surgical resection of gut lesions in pediatric Crohn's disease.

In pediatric Crohn's disease (CD), resection of gut lesions is necessary to remove stenoses and when frequent relapses occur despite nutritional support and medical treatment. After surgery, improved nutritional status and accelerated growth usually follow increased nutritional intake and lower doses of steroids. The aim of this study was to compare energy balance before and after surgery while nutritional intake and steroid therapy were unchanged. Eleven patients, aged 14.5 +/- 2.5 years and with mildly active CD, were explored 1 week before and 1 month after gut resection for stenosis (n = 7) and medical treatment failure (n = 4). Eleven matched children participated in the study as controls. Disease activity was assessed by the Pediatric Crohn's Disease Activity Index and serum orosomucoid concentration. Resting energy expenditure (REE) was measured by indirect calorimetry, and fat-free body mass (FFM) was measured by anthropometry. The patients' mean REE decreased from 46.6 +/- 10.5 kcal/kg FFM/day before surgery to 42.6 +/- 10.3 kcal/kg FFM/day after surgery, while the controls' mean REE was 39 +/- 7 kcal/kg FFM/day (analysis of variance, p = 0.02). After surgery, body weights were not significantly different, but the mean protein oxidation rate was reduced and arm muscle area was increased. Changes in REE per kilogram of FFM per day were not correlated with changes in orosomucoid serum concentrations (r2 = 0.35; p = 0.4). In conclusion, in children with mildly active CD, while nutritional intake and steroid therapy were maintained at preoperative levels, a significant decrease in REE and improved nitrogen utilisation were observed 1 month after resection of the CD gut lesion. This finding suggests better use of energy substrates when CD lesions are removed.

Adolescent↗