Biomedical subjects

F Vial

Publications and source records attributed to F Vial.

At least 19 recordsLinked to original sources

PubMed2006

Size, charge, and interactions with giant lipid vesicles of quantum dots coated with an amphiphilic macromolecule.

Semiconductor colloidal quantum dots (QDs) are promising fluorescent probes for biology. Initially synthesized in organic solvents, they can be dispersed in aqueous solution by noncovalent coating with amphiphilic macromolecules, which renders the particles hydrophilic and modifies their interactions with other biological compounds. Here, after coating QDs with an alkyl-modified polyacrilic acid, we investigated their colloidal properties in aqueous buffers by electrophoresis, electron microscopy, light scattering, and rate zonal centrifugation. Despite polymer dispersity and variation of the size of the inorganic nanoparticles, the polymer-dot complexes appeared relatively well-defined in terms of hydrodynamic radius and surface charge. Our data show that these complexes contain isolated QD surrounded by a polymer layer with thickness 8-10 nm. We then analyzed their interaction with giant unilamellar vesicles, either neutral or cationic, by optical microscopy. At neutral pH, we found the absence of binding of the coated particles to lipid membrane, irrespective of their lipid composition. An abrupt surface aggregation of the nanoparticles on the lipid membrane was observed in a narrow pH range (6.0-6.2), indicative of critical binding triggered by polymer properties. The overall features of QDs coated with amphiphilic polymers open the route to using these nanoparticles in vivo as optically stable probes with switchable properties.

Coated Materials, Biocompatible↗

PubMed2004

A newborn piglet study of moderate hypoxic-ischemic brain injury by 1H-MRS and MRI.

Cerebral hypoxia-ischemia (HI) is an important cause of perinatal brain damage in the term newborn. The areas most affected are the parasagittal regions of the cerebral cortex and, in severe situations, the basal ganglia. The aim of this study was to show that the newborn piglet model can be used to produce neuropathology resulting from moderate HI insult and to monitor damage for 7 days. Two acute cerebral HI were induced in newborn Large White piglets by reducing the inspired oxygen fraction to 4% and occluding the carotid arteries. Newborn piglets were resuscitated, extubated and monitored for 7 days. (31)P magnetic resonance spectroscopy (MRS) offers the ability to monitor the severity of the HI insults. Lactate (Lac) was detected in the HI group at 2 h, 3 days and 5 days after insult by (1)H MRS. Lac/n-acetylaspartate and Lac/choline and Lac/creatine ratios increased significantly (p < 0.01) in the HI group 2 h after HI insults and remained high over 7 days. For the HI group, mean T(2) values increased significantly in the parietal white matter (subcortical) for 5 days after HI insult [117.5 (+/-7.4) to 158.5 (+/-19.2) at T+3 days, 167.7 (+/-15.4) at T+5 days and 160.9 (+/-10.1) at T+7 days (p < 0.01)]. This newborn piglet model of moderate HI brain injury with reproducible cerebral damage could be use as reference for the study of neuroprotective strategy for a period of 7 days.

Animals↗

PubMed2004

Postoperative analgesia after total knee replacement: the effect of an obturator nerve block added to the femoral 3-in-1 nerve block.

Femoral nerve block (FNB) does not consistently produce anesthesia of the obturator nerve. In this single-blind, randomized, controlled study we added a selective obturator nerve block (ONB) to FNB to analyze its influence on postoperative analgesia after total knee replacement (TKR). Before general anesthesia, 90 patients undergoing TKR received FNB (Group 1), FNB and selective ONB (Group 2), or placebo FNB (Group 3). Postoperative analgesia was further provided by morphine IV via patient-controlled analgesia. Analgesic efficacy and side effects were recorded in the first 6 h after surgery. Adductor strength decreased by 18% +/- 9% in Group 1 and by 78% +/- 22% in Group 2 (P < 0.0001). Total morphine consumption was reduced in Group 2 compared with Groups 1 and 3 (P < or = 0.0001). Patients in Group 2 reported lower pain scores than those in Groups 1 and 3 (P = 0.0003). The incidence of nausea was more frequent in Groups 1 and 3 (P = 0.01). We conclude that FNB does not produce complete anesthesia of the obturator nerve. Single-shot FNB does not provide additional benefits on pain at rest over opioids alone in the early postoperative period. The addition of an ONB to FNB improves postoperative analgesia after TKR.

Aged↗

PubMed2003

[General anaesthesia for Caesarean section in a patient with pulmonary atresia and an intact intraventricular septum].

We report the case of a 22-year-old primigravida patient presenting pulmonary atresia with intact ventricular septum, a rare congenital heart disease. Caesarean delivery was performed at 32 weeks of gestation because of moderate maternal function deterioration and foetal growth restriction. General anaesthesia was used because of the presence of lumbar Harrington rods. The administration of etomidate, celocurine and a continuous perfusion of remifentanil right from induction ensured haemodynamic stability and a rapid emergence and recovery.

Adult↗

PubMed2002

[Antipublic antibodies and pregnancy: use of iron sucrose in autologous blood donation with cryopreservation].

An autologous blood donation with cryopreservation in a pregnant woman with natural antibody against a high frequency alloantigen is reported. A natural anti Gerbich antibody and a rare erythrocyte phenotype at high risk of polyimmunization was discovered during the third month of pregnancy. This leads to recommend the constitution of an autologous blood reserve. Before first sampling a moderate iron deficiency anaemia (10.3 g.dL-1) was treated with 600 mg of intravenous iron sucrose. Four blood packs of 350 mL were taken; after every sampling 200 mg of iron sucrose were injected intravenously. No maternal or foetal adverse effects occurred. Five weeks before delivery, an autologous blood reserve consisting in 4 cryopreserved red cells packs and 4 fresh frozen plasma was constituted. Epidural analgesia was used for delivery. No haemorrhage occurred. The reserve was not used and remained available for future use (one year for fresh frozen plasma and without limit for red cells).

Adult↗

PubMed2001

[Oculomotor paralysis and spinal anesthesia].

We describe a case of a parturient scheduled for Caesarean section in whom diplopia from abducens (sixth cranial) nerve palsy followed spinal anaesthesia performed with a 25 gauge Whitacre needle. After delivery, the patient experienced neckache, diplopia and postural headache successively. These symptoms were related to the dural puncture. Despite two consecutive epidural blood patches, no improvement of diplopia was observed. In 8 months, the nerve palsy had completely resolved.

Abducens Nerve Diseases↗

PubMed2000

[Postoperative pain and surgical treatment of trapeziometacarpal osteoarthritis of the thumb after ambulatory surgery].

OBJECTIVE: The course of pain and the incidence of the side effects from analgesics were evaluated for 15 days in 26 consecutive outpatients who underwent a surgical cure of trapeziometacarpal osteoarthritis of the thumb under regional block. STUDY DESIGN: Prospective study. METHODS: The analgesic regimen prescribed at discharge consisted on a regular administration of a combination of ketoprofen (50 mg.6.h-1) plus the association of acetaminophen and propoxyphene (two tablets.6.h-1). Patients were asked to evaluate their pain using a numerical rating scale graduated from 0 to 10. Data were collected during a telephone interview at day 4, 8 and 15. RESULTS: Overall, patients scrupulously followed the medical prescription. At day four, 80% of patients still needed analgesics. The mean period during which NSAID, acetaminophen and propoxyphene were maintained was 4 and 6 days respectively. Fifty percent of patients reported severe pain during postoperative day 1 and 2. Moderate pain was reported at day 3 and 4 in respectively 54% and 42% of cases. Beyond this period, most patients indicated pain of weak intensity (71% at day 8). Epigastric pain has been noticed for 27% of patients. CONCLUSION: The surgical correction of trapeziometacarpal osteoarthritis of the thumb is frequently performed according to an ambulatory setting. The fact that 50% of patients reported severe pain during the early postoperative period emphasize the inadequacy of our postoperative pain management for this surgical procedure.

Acetaminophen↗

PubMed1993

[Unexplained chronic diarrhea, apropos of 4 new cases under Cyclo 3 fort and review of the literature].

We report 4 cases of chronic diarrhoea in patients treated with Cylclo 3 fort. This side-effect was not mentioned in the French list of therapeutic drugs until 1992. The diarrhoea was without faeces and without glairy mucus or blood. Symptomatic treatments were totally ineffective. The diarrhoea itself was well tolerated, but 3 patients lost weight, with hypokalaemia in 2 of them, and 1 had regressive acute renal failure. The time elapsed between the first dose of Cyclo 3 fort and the diarrhoea ranged from 1 to 3 months, and it took 5 months to make the aetiological diagnosis. Two patients were hospitalized. Withdrawal of the drug always resulted in cure. One patient taking enemas developed a regressive subocclusion of the bowel. The physiopathological mechanism of this diarrhoea is unknown. These cases are similar to the 5 other cases reported in the literature.

Acute Kidney Injury↗

PubMed1983