Search PubMed⌕ Search

Biomedical subjects

P Gautier

Publications and source records attributed to P Gautier.

At least 19 recordsLinked to original sources
PubMed2003

Efficacy of selamectin against biting lice on dogs and cats.

The efficacy of selamectin was evaluated against naturally acquired Trichodectes canis infestations on dogs and against Felicola subrostratus infestations on cats. Twenty dogs and 18 cats were randomly allocated to treatment with either a placebo or selamectin (6 mg/kg), administered topically once only on day 0. The treatment had no adverse effects in either the dogs or the cats. Efficacy was assessed by counting the live lice (adults and nymphs) on each animal by using a coat-parting technique on days -3, 7, 14, 21, 28, 35 and 42 for the dogs, and on days -1, 7, 21, 35 and 42 for the cats. On day 43, the number of live lice on each dog was also assessed by using a whole-body combing technique. Selamectin was 100 per cent effective in killing biting lice on the dogs and cats throughout the period of assessment; the louse counts on the treated dogs and cats were significantly lower than the pretreatment counts (P = 0.0001) and were also significantly lower than on the placebo-treated dogs (P < 0.05) and cats (P = 0.0001). There was a marked reduction in the prevalence of clinical signs associated with ectoparasite infestation in the treated dogs and no clinical signs were observed in any of the treated cats.

Administration, Cutaneous↗
PubMed2002

Cost related to replacement therapy during hospitalization in haemophiliacs with or without inhibitors: experience of six French haemophilia centres.

Replacement therapy in haemophiliacs has a major economic impact on health establishments. We assessed in this prospective study the cost of clotting factor concentrate therapy for haemophilia A or B patients. We compared the overall costs of treated patients with or without inhibitors. In six French haemophilia centres, 278 consecutive hospitalizations were collected and analysed between June 97 and June 99. Haemophilia must be considered as the main cost factor during hospitalization. The severity of bleeds and surgical procedures increase the total cost. Furthermore, the daily and total costs are closely linked to the presence or the absence of inhibitors. This study should enable the hospital administration to evaluate the necessary resources to the clotting factor therapy in haemophiliacs with or without inhibitors during hospitalization.

Adolescent↗
PubMed2001

Electrophysiological effects of dronedarone (SR 33589), a noniodinated amiodarone derivative in the canine heart: comparison with amiodarone.

The electrophysiological effects of dronedarone, a new nonionidated analogue of amiodarone were studied after chronic and acute administration in dog Purkinje fibres, papillary muscle and isolated ventricular myocytes, and compared with those of amiodarone by applying conventional microelectrode and patch-clamp techniques. Chronic treatment with dronedarone (2x25 mg(-1) kg(-1) day p.o. for 4 weeks), unlike chronic administration of amiodarone (50 mg(-1) kg(-1) day p.o. for 4 weeks), did not lengthen significantly the QTc interval of the electrocardiogram or the action potential duration (APD) in papillary muscle. After chronic oral treatment with dronedarone a small, but significant use-dependent V(max) block was noticed, while after chronic amiodarone administration a strong use-dependent V(max) depression was observed. Acute superfusion of dronedarone (10 microM), similar to that of amiodarone (10 microM), moderately lengthened APD in papillary muscle (at 1 Hz from 239.6+/-5.3 to 248.6+/-5.3 ms, n=13, P<0.05), but shortened it in Purkinje fibres (at 1 Hz from 309.6+/-11.8 to 287.1+/-10.8 ms, n=7, P<0.05). Both dronedarone (10 microM) and amiodarone (10 microM) superfusion reduced the incidence of early and delayed afterdepolarizations evoked by 1 microM dofetilide and 0.2 microM strophantidine in Purkinje fibres. In patch-clamp experiments 10 microM dronedarone markedly reduced the L-type calcium current (76.5+/-0.7 %, n=6, P<0.05) and the rapid component of the delayed rectifier potassium current (97+/-1.2 %, n=5, P<0.05) in ventricular myocytes. It is concluded that after acute administration dronedarone exhibits effects on cardiac electrical activity similar to those of amiodarone, but it lacks the 'amiodarone like' chronic electrophysiological characteristics.

Action Potentials↗
PubMed2001

Intrathecal ropivacaine and clonidine for ambulatory knee arthroscopy: a dose-response study.

BACKGROUND: The aim of this study was to evaluate the association of a small dose of intrathecal ropivacaine with small doses of intrathecal clonidine for ambulatory surgery. METHODS: One hundred twenty patients, classified as American Society of Anesthesiologists physical status I and scheduled for knee arthroscopy, were studied. Patients were randomly assigned to receive 4 ml of one of the following double-blinded isobaric intrathecal solutions: 8 mg of ropivacaine (group 1; n =30); 8 mg ropivacaine plus 15 microg clonidine (group 2; n =30); 8 mg ropivacaine plus 45 microg clonidine (group 3; n =30); and 8 mg ropivacaine plus 75 microg clonidine (group 4; n =30). The level and duration of sensory anesthesia were recorded, along with the intensity and duration of motor block. Patient and surgeon were interviewed to evaluate the quality of anesthesia. RESULTS: Intrathecal ropivacaine (8 mg alone) produced short sensory anesthesia and motor blockade (132 +/- 38 min and 110 +/- 35 min; mean +/- SD). However, the quality of anesthesia was significantly lower than in any other group (P < 0.05). Ropivacaine (8 mg) plus 75 microg clonidine produced significantly longer sensory and motor anesthesia (195 +/- 40 min and 164 +/- 38 min; P < 0.05). However, this was associated with systemic effects, such as sedation and reduction of arterial blood pressure. Ropivacaine (8 mg) plus 15 microg clonidine did not prolong sensory or motor blockade, afforded high quality anesthesia, and was not associated with detectable systemic effects. CONCLUSION: Small-dose intrathecal clonidine (15 microg) plus 8 mg intrathecal ropivacaine produces adequate and short-lasting anesthesia for knee arthroscopy.

Adrenergic alpha-Agonists↗
PubMed2000

The comparative toxicity of ropivacaine and bupivacaine at equipotent doses in rats.

We compared the toxicity of systemic local anesthetics bupivacaine and ropivacaine administered at equivalent and equipotent doses. In the first experiments, 18 male Wistar rats were anesthetized with thiopental and maintained under positive controlled ventilation. Electrocardiogram, electroencephalogram, and invasive arterial blood pressure were continuously recorded. The animals were randomly assigned to receive 3 mg x kg(-1) x min(-1) bupivacaine, 3 mg x kg(-1) x min(-1) ropivacaine IV (equivalent group), or 4.5 mg x kg(-1) x min(-1) ropivacaine (equipotent group). The timing of the occurrence of local anesthetic-induced toxic events (defined as the first QRS modification, dysrhythmia, seizures, moderate and severe bradycardia and hypotension, final systole) was recorded and the dose calculated. Eighteen additional rats, treated according to the same protocol were killed at the time of moderate, severe, and final hypotension for blood sampling and plasma bupivacaine and ropivacaine concentration measurement. In a third experiment, 15 awake rats (5 per group) received IV bupivacaine or ropivacaine (same infusion as in the first experiments) until seizure. At this moment, rats were allowed to recover from local anesthetic intoxication. In the first experiment, except for the first QRS modification, all the other toxic manifestations occurred at significantly larger doses (P<0.05) in the two ropivacaine groups in comparison to the bupivacaine group. In awake rats, all the animals intoxicated by ropivacaine easily recovered. In the bupivacaine group, two animals required cardiopulmonary resuscitation before any seizure activity could be detected, and only three rats survived. We conclude that, in the model used, ropivacaine, even at an equipotent dose, is less toxic than bupivacaine.

Amides↗
PubMed2000

Hemodynamic and antiadrenergic effects of dronedarone and amiodarone in animals with a healed myocardial infarction.

The hemodynamic and antiadrenergic effects of dronedarone, a noniodinated compound structurally related to amiodarone, were compared with those of amiodarone after prolonged oral administration, both at rest and during sympathetic stimulation in conscious dogs with a healed myocardial infarction. All dogs (n = 6) randomly received orally dronedarone (10 and 30 mg/kg), amiodarone (10 and 30 mg/kg), and placebo twice daily for 7 days, with a 3-week washout between consecutive treatments. Heart rate (HR), mean arterial pressure (MBP), positive rate of increase of left ventricular pressure (+LVdP/dt), echocardiographically assessed left ventricular ejection fraction (LVEF), and fractional shortening (FS), as well as chronotropic response to isoproterenol and exercise-induced sympathetic stimulation were evaluated under baseline and posttreatment conditions. Resting values of LVEF, FS, +LVdP/dt, and MBP remained unchanged whatever the drug and the dosing regimen, whereas resting HR was significantly and dose-dependently lowered after dronedarone and to a lesser extent after amiodarone. Both dronedarone and amiodarone significantly reduced the exercise-induced tachycardia and, at the highest dose, decreased the isoproterenol-induced tachycardia. Thus, dronedarone and amiodarone displayed a similar level of antiadrenergic effect and did not impair the resting left ventricular function. Consequently, dronedarone might be particularly suitable for the treatment and prevention of various clinical arrhythmias, without compromising the left ventricular function.

Adrenergic Antagonists↗
PubMed2000

Inhibitory effects of dronedarone on muscarinic K+ current in guinea pig atrial cells.

Dronedarone (SR33589), an amiodarone-like noniodinated antiarrhythmic agent, is undergoing clinical trials in atrial fibrillation. Because vagal activation plays a role in the pathophysiology of supraventricular arrhythmias, we have assessed the ability of dronedarone (0.01, 0.1, and 1 microM), compared with amiodarone (0.1, 1, and 10 microM) to inhibit the muscarinic acetylcholine receptor-operated K+ current (I(K(ACh))) in single cells isolated from guinea pig atria (patch-clamp technique). I(K(ACh)) was activated by extracellular application of carbachol (10 microM) or by intracellular loading with GTP-gamma-S (100 microM). Dronedarone and amiodarone reduced the carbachol-induced I(K(ACh)) with an IC50 (concentration required for 50% inhibition) slightly above 10 nM and 1 microM, respectively. Dronedarone also inhibited the GTP-gamma-S induced K+ current by 28% and 58% at 0.01 and 0.1 microM, respectively. These data suggest that dronedarone inhibits I(K(ACh)) by depressing the function of K(ACh) channel itself or associated GTP-binding proteins. Compared with amiodarone, dronedarone is approximately 100 times more potent on I(K(ACh)) and seems more selective in inhibiting I(K(ACh)) with respect to its antagonism of other inward and outward currents reported in the literature. This relative high potency of dronedarone to reduce I(K(ACh)) may be involved, at least in part, in the antiarrhythmic action of dronedarone against atrial fibrillation.

Amiodarone↗
PubMed2000

Switching behavior and electro-optical properties of liquid crystals in nematic gels

Anisotropic nematic gels are prepared via in situ polymerization of diacrylate monomers in an orientated nematic liquid crystal (LC) matrix. The switching behavior of the LC molecules under electric field is probed in polarized Raman spectroscopy and straight theta-2straight theta elastic light scattering experiments. The electro-optical characteristics of the gels are directly related to the electric field dependence of the fraction of switched molecules. The electro-optical contrast relates to the coexistence of switched LC domains and LC domains anchored to the polymer network.

Journal Article↗
PubMed2000

Cellular and in vivo electrophysiological effects of dronedarone in normal and postmyocardial infarcted rats.

We studied the effects of dronedarone (SR 33589) on the action potentials, membrane ionic currents, and arrhythmic activity in control rats and in rats after myocardial infarction, a model known to develop anomalous electrical activity. Dronedarone increased action potential duration in normal hearts. It had little effect on the action potentials that were already prolonged in the postmyocardial infarcted (PMI) rats. Particularly, dronedarone reduced the late sustained K(+) current, I(K) (or Isus) by 69%. Dronedarone induced only a tonic block of I(K). Similar relative inhibitions of I(K) by dronedarone were obtained in young, sham, and PMI rats, even if I(K) was less in sham than in young and further reduced in PMI rats. The EC(50) values were 0.78 and 0.85 microM in sham and PMI rats. Dronedarone induced a weak increase in the fast transient outward current, I(to). Time-to-peak and inactivation time constant of I(to) were decreased by dronedarone that also induced a marked slowing of I(to) recovery from inactivation. Similar effects were observed on the reduced I(to) recorded in PMI rats. Holter monitoring study in control, unthetered animals showed that dronedarone had no proarrhythmic effect. On rats, which after myocardial infarction exhibited ventricular premature beats, dronedarone significantly decreased beat occurrence during the 7-day treatment; this effect was sustained for two more weeks. Thus, dronedarone exerts antiarrhythmic effects on PMI rat heart. Its effects are attributable for the most part to the inhibition of outward K(+) currents and the increase in effective refractory period.

Action Potentials↗
PubMed1999

A double-blind comparison of 0.125% ropivacaine with sufentanil and 0.125% bupivacaine with sufentanil for epidural labor analgesia.

BACKGROUND: This study intends to evaluate the benefits of the administration of intermittent bolus doses of ropivacaine (0.125%) compared with bupivacaine (0.125%) after addition of sufentanil for analgesia during labor. METHODS: One hundred thirty American Society of Anesthesiologists physical status 1 or 2 parturients were studied. The 90 initial patients were assigned randomly to receive 10 ml bupivacaine, 0.125%, plus 7.5 microg sufentanil (initial bupivacaine 0.125% group) or ropivacaine, 0.125%, plus 7.5 microg sufentanil (ropivacaine 0.125% group). Forty additional patients were recruited and received 0.125% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.125% group) or 0.100% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.100% group). The duration of analgesia, visual analogue scores for pain, motor blockade (using a six-point modified Bromage scale), patient satisfaction scores, nausea, pruritus, heart rate, and blood pressure were recorded. RESULTS: Bupivacaine 0.125% and ropivacaine 0.125% coadministered with sufentanil provided rapid and complete analgesia. Onset of analgesia occurred after +/-15 min and lasted +/-90 min. After the third epidural injection, patients in the ropivacaine group experienced significantly less severe motor blockade than patients in the initial bupivacaine 0.125% group. At this point, 93% of the patients in the ropivacaine group were free from motor impairment versus 66% in the bupivacaine group (P<0.05). Comparable levels of motor blockade were obtained in both additional groups. Patients' evaluation of their analgesia was worst in the bupivacaine 0.100% group. CONCLUSIONS: Ropivacaine 0.125% with sufentanil affords reliable analgesia with minimal motor blockade.

Adult↗
PubMed1999

Epidural clonidine or bupivacaine as the sole analgesic agent during and after abdominal surgery: a comparative study.

BACKGROUND: The rationale of this study was to compare high-dose epidural clonidine with a more commonly used agent, such as bupivacaine. This was performed to give a more objective idea of the relative analgesic potency of epidural clonidine. METHODS: Sixty patients undergoing intestinal surgery during propofol anesthesia were studied. At induction, the patients received epidurally a dose of 10 micrograms/kg [corrected] clonidine in 7 ml saline followed by an infusion of 6 micrograms [corrected] x kg(-1) x h(-1) (7 ml/h) (group 1, n = 20), a dose of 7 ml bupivacaine, 0.5%, followed by 7 ml/h bupivacaine, 0.25% (group 2, n = 20), or a dose of 7 ml bupivacaine, 0.25%, followed by 7 ml/h bupivacaine, 0.125% (group 3, n = 20). Intraoperatively, increases in arterial blood pressure or heart rate not responding to propofol (0.5 mg/kg) were treated with intravenous alfentanil (0.05 mg/kg). Additional doses of propofol were given to maintain an adequate bispectral index. The epidural infusions were maintained for 12 h. In cases of subjective visual analogue pain scores up to 5 cm at rest or up to 8 cm during coughing, the patients were given access to a patient-controlled analgesia device. RESULTS: During anesthesia, patients in group 1 required less propofol than those in groups 2 and 3 (78 [36-142] mg vs. 229 [184-252] mg and 362 [295-458] mg; P < 0.05) and less alfentanil than patients in group 3 (0 [0-0] mg vs. 11 [6-20] mg; P < 0.05). Analgesia lasted 380 min (range, 180-645 min) in group 1 versus 30 min (range, 25-40 min) in group 2 and 22 min (range, 12.5-42 min) in group 3 (P < 0.05). There was no suggestion of a hemodynamic difference among the three groups except for heart rates that were significantly reduced in patients in group 1. Sedation scores were significantly higher in this group during the first 2 h postoperatively. CONCLUSION: Our results show that high doses of epidural clonidine potentiate general anesthetics and provide more efficient postoperative analgesia than the two bupivacaine dosage regimens investigated.

Abdomen↗
PubMed1998

Expression and function of tap in the gustatory and olfactory organs of Drosophila.

We have recently described the identification of a gene, tap, which encodes a bHLH protein expressed in one neuron of each larval chemosensory organ. Here we show that tap is expressed at a late stage in the development of one type of adult chemosensory organ, the gustatory bristles of the leg, wing and proboscis. We also show that tap is expressed very early in the development of a second type of chemosensory receptors, the olfactory organs of the antenna. The results of behavioral experiments suggest that the ectopic expression of tap affects the response to sugar and salt.

Animals↗
PubMed1997

tap, a Drosophila bHLH gene expressed in chemosensory organs.

We have isolated a Drosophila bHLH gene, tap, that is expressed in a small subset of neurons when they undergo differentiation. In the peripheral nervous system, tap is expressed exclusively in one of the neurons that innervate each larval chemosensory organ, possibly controlling the specific properties of that neuron. Sequence comparisons suggest that tap is most closely related to two bHLH genes identified in several vertebrate species, neurogenin and neuroD, which are involved respectively in neural determination and in neuronal differentiation.

Amino Acid Sequence↗
PubMed1994

SR47063, a potent channel opener, activates KATP and a time-dependent current likely due to potassium accumulation.

(i) We studied the effects of a new cromakalim analogue, SR47063, in guinea-pig ventricular cells. The experiments were carried out in whole-cell patch clamp with internal and external solutions supposedly similar to the physiological ones. (ii) SR47063 reversibly activated a time-independent current reversing near the potassium equilibrium potential, and a time-dependent current reversing at a more positive potential. Both currents were blocked by application of glibenclamide. (iii) The time-independent and the time-dependent currents were activating for the same concentration of agonist in every cell, this concentration being very different from cell to cell. (iv) The amplitude of the time-dependent current was shown to depend directly neither on agonist concentration nor on potential, but rather on the amplitude of the current flowing during the prepulse before the test pulse. (v) We conclude that SR47063 is a potent KATP channel opener acting at concentrations lower than one micromolar, and that the time-dependent current is likely due to accumulation and depletion of potassium in restricted areas of the cells.

Adenosine Triphosphate↗
PubMed1994

[Mesentric venous thrombosis. Risk factors, treatment and outcome. An analysis of 18 cases].

Eighteen patients with an acute thrombosis of the splanchnic veins were reviewed. Most of apparently idiopathic cases of splanchnic vein thrombosis are related to an increased coagulation related to a congenital or acquired defect of haemostasis. The aim of this study was to assess the effects of a new and effective treatment. Nine male and 9 female patients (range of age: 19 to 81 years) experienced a mesenteric venous thrombosis. There were 14 mesenteric vein thromboses with infarction, two transient mesenteric venous ischaemias without bowel infarction and two acute thromboses of the splanchnic veins without bowel ischaemia. A coagulopathy was detected in seven patients: oral contraception, protein C (PC) or antithrombin III (AT III) congenital deficiencies, acquired deficiency of AT III, PC and protein S (PS), polycythaemia in the post-partum period and primary myeloproliferative disorder. No coagulopathy was associated with thrombosis in eight cases: mesenteric haematoma, splenomegaly, cirrhosis, appendicectomy, cholescytectomy, chronic heart failure, treatment with beta-adrenergic receptor antagonist and digitalis, stenosis of the portal anastomosis after liver transplantation. Twelve patients required surgery: eight intestinal bowel resections with immediate anastomosis, four resections without immediate anastomosis. Only one patient underwent a second look for a repeat bowel resection. No death occurred in the early postoperative period and 17 out of 18 patients were alive after 12 years. An oral anticoagulant therapy was undertaken from two months to seven years. However, three patients suffered a recurrent thrombosis. Two of them required a long-term anticoagulation. Six patients experienced a portal hypertension and oral anticoagulants were discontinued in three of them because of bleeding oesophageal varices. Six patients were treated only by unfractionated heparin (UFH) or low molecular weight heparin (LMWH) followed by oral anticoagulants. After laparotomy, two were only treated with UFH without any bowel resection, as mesenteric venous ischaemia was too extensive. These observations suggest that the choice between an appropriate medical or surgical treatment is important and must be discussed. Since 1989, the therapeutic choice has been modified by ultrasonography and contrast enhanced computed tomographic scan which confirms diagnosis, allows to follow up and check the effects of anticoagulation and to choose the time for surgery. When the diagnosis is established and the patient's risk is low, the IU . kg(-1) . d(-1) to obtain an antifactor Xa activity between 0.3 and 0.6 antiXa IU mL(-1). When the diagnosis is uncertain and the patient's risk if high a laparotomy is required.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

[Venous thromboembolic disease in a geriatric environment. Importance of its detection and treatment].

The elderly population is particularly exposed to risk of venous thromboembolism because the risk of thrombosis increases with age but also because of the side effects of anticoagulant therapy. Clinical signs are neither sensitive nor specific and systematic screen for deep vein thrombosis in elderly patients could be justified using noninvasive techniques such as echo-Doppler or assay of D-Dimers. The aim of this study was to determine the prevalence of venous thrombosis diagnosed by echo-Doppler screening in a population of institutionalized elderly subjects. The frequency of risk factors and the cost of screening and subsequent health care were also evaluated. This study included 96 patients who underwent systematic echo-Doppler measurements. Clinical, biological and echographic data were recorded on individual file-cards for analysis. The prevalence of deep vein thrombosis diagnosis was 13.5% (13/96). All the deep vein thromboses discovered were in the popliteal area. No high risk group was found and there was found and there was no significant link with clinical signs or the level of D-Dimers. The cost of diagnosis and treatment in the particular conditions of our study were 5000 and 10,700 FRF respectively for each deep vein thrombosis diagnosed. The cost of diagnostic screening and treatment should be considered in light of the life expectancy and quality of life in this population. Thus in elderly institutionalized subjects, it would appear not to be reasonable to undertake systematic screening for venous thrombosis using echo-Doppler or D-Dimer assay.

Aged↗
PubMed1993

Free cortisol in serum assayed by temperature-controlled ultrafiltration before fluorescence polarization immunoassay.

A method is described for a temperature-controlled ultrafiltration procedure to measure free cortisol in serum. A special thermometer with a sensor was developed, measuring the temperature directly in the ultrafiltration device. The sensor is screwed on the axis of the centrifuge rotor, and the centrifuge is placed in a temperature-controlled box so that the temperature of the sample is kept at 37 degrees C +/- 0.1 degrees C. The overall CV of the free cortisol assay ranges from 2.2% to 11.4%, of which the ultrafiltration contributes only 2.2-3.6%. Increasing amounts of cortisol-binding protein, as found in women using estrogen-containing oral contraceptives, have minor but significant effects on the free cortisol concentrations in serum. Serum free cortisol concentrations in a reference population (n = 114; central 95 percentiles) were 12-43 nmol/L (4-9.5% of total cortisol); in the group of the oral-contraceptive users (n = 27), the reference interval was 11-53 nmol/L (1.5-4.5%).

Blood Preservation↗