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R Bordet

Publications and source records attributed to R Bordet.

At least 19 recordsLinked to original sources
PubMed2006

Improvement of gait by chronic, high doses of methylphenidate in patients with advanced Parkinson's disease.

BACKGROUND: Therapeutic management of gait disorders in patients with advanced Parkinson's disease (PD) can sometimes be disappointing, since dopaminergic drug treatments and subthalamic nucleus (STN) stimulation are more effective for limb-related parkinsonian signs than for gait disorders. Gait disorders could also be partly related to norepinephrine system impairment, and the pharmacological modulation of both dopamine and norepinephrine pathways could potentially improve the symptomatology. AIM: To assess the clinical value of chronic, high doses of methylphenidate (MPD) in patients with PD having gait disorders, despite their use of optimal dopaminergic doses and STN stimulation parameters. METHODS: Efficacy was blindly assessed on video for 17 patients in the absence of L-dopa and again after acute administration of the drug, both before and after a 3-month course of MPD, using a Stand-Walk-Sit (SWS) Test, the Tinetti Scale, the Unified Parkinson's Disease Rating Scale (UPDRS) part III score and the Dyskinesia Rating Scale. RESULTS: An improvement was observed in the number of steps and time in the SWS Test, the number of freezing episodes, the Tinetti Scale score and the UPDRS part III score in the absence of L-dopa after 3 months of taking MPD. The L-dopa-induced improvement in these various scores was also stronger after the 3-month course of MPD than before. The Epworth Sleepiness Scale score fell dramatically in all patients. No significant induction of adverse effects was found. INTERPRETATION: Chronic, high doses of MPD improved gait and motor symptoms in the absence of L-dopa and increased the intensity of response of these symptoms to L-dopa in a population with advanced PD.

Aged↗
PubMed2006

Prior TIA, lipid-lowering drug use, and physical activity decrease ischemic stroke severity.

OBJECTIVE: To determine clinical and pharmacologic factors that could influence the initial severity and short-term outcome of cerebral ischemia. METHODS: In a cross-sectional hospital-based study of patients with acute supratentorial ischemic stroke, we systematically collected medical history, previous leisure-time physical activity, current and previous treatments, blood pressure, temperature, blood glucose, fibrinogen, NIH Stroke Scale (NIHSS) score at admission, and outcome at day 8. Factors potentially associated with initial stroke severity and outcome were selected by univariate analyses and then validated in logistic regression analyses with lower severity of stroke at admission (NIHSS 0 to 5) or good outcome at day 8 (modified Rankin Scale 0 to 1, Barthel Index 95 to 100) as dependent variables. RESULTS: In 362 consecutive patients (median age 70 years, range 16 to 97 years; 195 women), independent factors associated with a lower severity at admission were previous leisure-time physical activity (adjusted odds ratio [OR] 1.67, 95% CI 1.07 to 2.66), TIA (adjusted OR 2.28, 95% CI 1.06 to 4.87) and treatment with lipid-lowering drug (adjusted OR 1.76, 95% CI 1.02 to 3.03). Previous treatment with lipid-lowering drug and leisure-time physical activity were also independent factors associated with a good short-term outcome. CONCLUSION: Both regular physical activity and lipid-lowering drugs should be prospectively evaluated to determine whether they reduce the severity of ischemic stroke.

Adolescent↗
PubMed2006

PPAR: a new pharmacological target for neuroprotection in stroke and neurodegenerative diseases.

PPARs (peroxisome-proliferator-activated receptors) are ligand-activated transcriptional factor receptors belonging to the so-called nuclear receptor family. The three isoforms of PPAR (alpha, beta/delta and gamma) are involved in regulation of lipid or glucose metabolism. Beyond metabolic effects, PPARalpha and PPARgamma activation also induces anti-inflammatory and antioxidant effects in different organs. These pleiotropic effects explain why PPARalpha or PPARgamma activation has been tested as a neuroprotective agent in cerebral ischaemia. Fibrates and other non-fibrate PPARalpha activators as well as thiazolidinediones and other non-thiazolidinedione PPARgamma agonists have been demonstrated to induce both preventive and acute neuroprotection. This neuroprotective effect involves both cerebral and vascular mechanisms. PPAR activation induces a decrease in neuronal death by prevention of oxidative or inflammatory mechanisms implicated in cerebral injury. PPARalpha activation induces also a vascular protection as demonstrated by prevention of post-ischaemic endothelial dysfunction. These vascular effects result from a decrease in oxidative stress and prevention of adhesion proteins, such as vascular cell adhesion molecule 1 or intercellular cell-adhesion molecule 1. Moreover, PPAR activation might be able to induce neurorepair and endothelium regeneration. Beyond neuroprotection in cerebral ischaemia, PPARs are also pertinent pharmacological targets to induce neuroprotection in chronic neurodegenerative diseases.

Brain↗
PubMed2006

A recovery model of minimally invasive cardiopulmonary bypass in the rat.

This study was undertaken to develop a rodent (rat) model of cardiopulmonary bypass (CPB) that has been designed to mimic functionally the minimally invasive clinical setting. The circuit is similar to the clinical model in terms of its construction, configuration, material surface area to blood volume ratio, and priming volume to blood ratio. The overall priming volume was 10 mL. Thirty-six male Sprague-Dawley rats (422 +/- 32 g) were anaesthetized while maintaining spontaneous ventilation. Anticoagulation was achieved with heparin (500 IU/kg). Blood arterial pressure was monitored continuously. Normal central temperature was maintained throughout. Intermittent arterial blood gas levels also were monitored. All animals were cannulated in preparation for CPB; however, CPB, utilizing a double roller pump and a flow rate of 100 mL/kg/minute for 60 min, was initiated in only 18 animals, the remaining 18 animals acting as non-CPB controls (Sham). The animals were haemodynamically stable. After the operative procedure, the animals were allowed to recover from the anaesthesia and, after transfer to a recovery facility, were monitored for a period of 1 week. There were no differences between the groups in terms of blood gas analysis and blood pressure data; all animals survived the procedure and had an uneventful follow-up. Differences were found between the CPB animals and the Sham group in terms of TNFalpha used as a marker of inflammatory processes. This trend tends to support this model as an analogue for the clinical scenario for future studies of CPB-related inflammation. Overall, the CPB procedure was easy to perform and was associated with excellent survival. This recovery model is an effective tool to perform pathophysiological studies associated with minimally invasive CPB.

Animals↗
PubMed2005

Lipid lowering agents are associated with a slower cognitive decline in Alzheimer's disease.

BACKGROUND: Data from epidemiological studies and animal models imply that disturbances in cholesterol metabolism are linked to Alzheimer's disease susceptibility. Lipid lowering agents (LLAs) may have implications for the prevention of Alzheimer's disease. OBJECTIVE: To investigate whether LLAs are associated with a slower cognitive decline in Alzheimer's disease. METHODS: An observational study in 342 Alzheimer patients followed in a memory clinic for 34.8 months (mean age 73.5 years, mini-mental state examination score (MMSE) 21.3 at entry); 129 were dyslipaemic treated with LLAs (47% with statins), 105 were untreated dyslipaemic, and 108 were normolipaemic. The rate of cognitive decline was calculated as the difference between the first and last MMSE score, divided by the time between the measurements, expressed by year. Patients were divided into slow and fast decliners according to their annual rate of decline (lower or higher than the median annual rate of decline in the total population). RESULTS: Patients treated with LLAs had a slower decline on the MMSE (1.5 point/year, p = 0.0102) than patients with untreated dyslipaemia (2.4 points/year), or normolipaemic patients (2.6 points/year). Patients with a slower decline were more likely to be treated with LLAs. Logistic regression analysis, with low annual cognitive decline as the dependent variable, showed that the independent variable LLA (treated with or not) was positively associated with the probability of lower cognitive decline (odds ratio = 0.45, p = 0.002). CONCLUSIONS: LLAs may slow cognitive decline in Alzheimer's disease and have a neuroprotective effect. This should be confirmed by placebo controlled randomised trials in patients with Alzheimer's disease and no dyslipaemia.

Aged↗
PubMed2004

[Central dopamine receptors: general considerations (Part 1)].

Specific protein G-coupled receptors mediate the effects of dopamine in its projection areas. Five dopaminergic receptors have been cloned, characterized and classified in two families, the D1-like family (D1- and D5-receptor subtypes) and the D2-like family (D2-, D3- and D4-receptor subtypes). These five dopamine receptor subtypes are characterized by their diversity in terms of transduction, distribution, pharmacology, functions, and regulation, leading to pleiotropic pathophysiological and pharmacological involvements in neuropsychiatric disorders underlain by a deregulation of the dopaminergic system.

Animals↗
PubMed2004

[Central dopaminergic receptors (Part II): pathophysiological and therapeutic considerations].

The five subtypes of dopaminergic receptors exhibit different transduction, cerebral localization, regulation, pharmacological, and physiological roles, explaining their multiple pathophysiological implications in different neuropsychiatric conditions which result, at least in part from anomalous dopaminergic neurotransmission: Parkinson's disease, schizophrenia, addiction, migraine, mode disorders, Gilles de la Tourette disease, hyperactivity syndrome with attention deficit. The wide range of pharmacological implications explains the diversity of the therapeutic approaches perspectives for development of new drugs for these neuropsychiatric conditions.

Attention Deficit Disorder with Hyperactivity↗
PubMed2004

[Drug-resistant partial epilepsy: pharmacological criteria].

Despite the number of new antiepileptic drugs marketed in the last decade, one third of epilepsies have remained refractory to medical treatment. The term of pharmacoresistance remains controversial and a diagnosis algorithm should be proposed to distinguish pseudoresistance related to the pathology and patient or to the treatment. Beyond resistance to the first prescribed antiepileptic, a lack of response to the sequential use of several monotherapies or antiepileptic drug associations should lead to the diagnosis of drug-resistance, when all causes of pseudoresistance have been ruled out. The presence of predicting factors or etiological factors should also be integrated into this decisional algorithm. Such a diagnostic process identifying real drug-resistant epilepsy is necessary to progress in knowledge of the pathophysiology and in treatment strategy of this category of epilepsy.

Anticonvulsants↗
PubMed2003

Heart rate variability and Parkinson's disease severity.

Heart rate variability (HRV) decrease in Parkinson's disease (PD) could only be a consequence of reduce motor activity besides of being a marker of cardiovascular dysautonomia. Under continuously recorded and standardised motor activity, we studied thirty patients compared to controls in 3 PD stages: group I: less than 2 year-evolution, slight impaired without L-dopa; group II: mildly impaired with L-dopa; group III: advanced PD with motor complications. No difference was observed between group I and controls. The diurnal low frequency power (LF) and the ratio of LF/high frequency (HF) power decreased in groups II and III. The nocturnal vagal indicators: HF power and pNN50 were decreased in group III. Those parameters were correlated with Off-drug-motor handicap, suggesting an evolutive HRV decrease with disease severity but not with On-drug-motor activity. The low LF despite the higher motor activity in group III, due to dyskinesias, suggested a defective cardiovascular up-regulation.

Autonomic Nervous System Diseases↗
PubMed2002

[Continuous dopaminergic stimulation, pulsatile dopaminergic stimulation].

Levodopa is the gold standard treatment for Parkinson's disease. The therapeutic effect may however be compromised by the inevitable risk of motor complications, with fluctuating motor control and dyskinesia, particularly in the younger patient. The Multiple pathophysiological mechanisms are undoubtedly involved but pulsed dopaminergic stimulation appears to play a determining role. This underlines the importance of a treatment which achieves a most stable and physiological dopaminergic stimulation as possible. Dopaminergic agonists provide a promising alternative. Another possibility is to modulate the peripheral kinetics of levodopa as soon as it is introduced using catechol-O-methyl transferase inhibitors.

Antiparkinson Agents↗
PubMed2001

The dopamine D3 receptor and drug addiction.

Hedonic and reinforcing properties of drugs of abuse are closely related to brain dopamine neuron activity. All these drugs increase dopamine release in the shell of the nucleus accumbens, a brain region in which neurons co-express the D1 (D1R) and D3 (D3R) dopamine receptor subtypes, that converging pharmacological, human post-mortem and genetic studies suggest to be implicated in drug addiction. The D3R through a cross-talk with the D1R, is involved in induction and expression of behavioral sensitization to levodopa in rats bearing unilateral lesions of dopamine neurons. Behavioral sensitization, a cardinal feature of addiction arises from repeated administration of drugs of abuse thought to play a role in intensification of reinforcing efficacy of these drugs observed under certain conditions. Stimulation of the D3R also appears to enhance the reinforcing effect of cocaine in rats. By interacting with these processes, D3R agents have potential therapeutic applications for treating drug addiction. BP 897 (N-[4-(4-(2-methoxyphenyl)piperazin-1-yl) butyl] naphtalen 2-carboxamide dichlorhydrate), a partial and highly selective D3R agonist in vitro, behaves as an agonist or an antagonist in vivo depending on the response considered. BP 897 has the unprecedented property to reduce cocaine-seeking behavior induced by presentation of a cocaine-associated cue, without having any intrinsic reinforcing effect. As drug-associated cues maintain drug-seeking in animals and elicit craving and relapse in humans, D3R agents like BP 897 may represent new medications for drug addiction, with minimal liability to maintaining dependence.

Journal Article↗
PubMed2001

Analysis of the direct cost of adverse drug reactions in hospitalised patients.

The hospitalised patients in a cardiological hospital (Lille, France) over an 18-month period were subjected to a prospective high-intensity adverse drug reaction (ADR) monitoring in order to assess the additional financial resource utilisation associated with ADRs and analyse the distribution of excess of cost according to ADR nature and therapeutic classes. Over 18 months, among the 16,916 hospitalised patients, 371 verified ADRs detected by self-report stimulated by a special unit of nurses and pharmacologists occurred in 336 patients with an overall ADR rate of 2.2%. This rate increased with age. The most common reactions were cutaneous events (24%), cardiovascular events (21%), metabolic disorders (12%), coagulation disorders (10%) and nervous system impairment (10%). The most common drug classes involved were cardiovascular agents (36%), contrast media (20%), drugs affecting blood clotting (13%) and anti-infectives (14%). Increased ADR-induced costs result especially from prolongation of length of stay and cost increase was evaluated at Euro 4150 per ADR. Among the 371 ADRs, 134 ADRs, which were significantly more severe, induced a prolongation of length of stay. Renal insufficiency and cardiovascular events were significantly over-represented in this sub-group. The most common ADR-inducing drugs associated with a prolongation of length of stay are cardiovascular agents and drugs affecting blood clotting. In contrast, cutaneous ADRs were significantly over-represented in the group of ADRs without prolongation of length of stay. The severity and substantial costs of ADRs in hospital justify investments to prevent these events. Nevertheless, only a portion of ADRs induces cost increases, suggesting that prevention efforts should focus on this limited category of ADRs.

Adult↗
PubMed2001

Beneficial effect of glycoprotein IIb/IIIa inhibitor (AZ-1) on endothelium in Escherichia coli endotoxin-induced shock.

OBJECTIVE: To investigate the effects of AZ-1, a murine monoclonal antiglycoprotein-IIb/IIIa antibody, on endothelium and on hemostasis in a rabbit endotoxic shock model. DESIGN: Prospective laboratory study. SETTING: University laboratory. SUBJECTS: Thirty-five male New-Zealand rabbits. INTERVENTIONS: In vitro vascular reactivity, endothelium CD31-PECAM1 immunohistochemistry, plasma coagulation factors, and monocyte tissue factor determination were performed 1 day and/or 5 days after onset of endotoxic shock (0.5 mg/kg, intravenous bolus,Escherichia coli lipopolysaccharide) with or without treatment by AZ-1 (0.5 mg/kg intravenously) given 1 hr after lipopolysaccharide injection. MEASUREMENTS AND MAIN RESULTS: Metabolic acidosis and coagulation activation confirmed the presence of shock. AZ-1 treatment improved endothelial-dependent relaxation at 1 day (maximal effect = 87.2 +/- 4.0% vs. 60.9 +/- 5.2% in the nontreated group, p <.05) and at 5 days (maximal effect = 84.5 +/- 3.5% vs. 56.6 +/- 8.2% in the nontreated group, p <.05). Endotoxin-induced endothelial injury was decreased significantly by AZ-1 at 1 day (6.4 +/- 1.9% vs. 10.3 +/- 0.8% in the nontreated group, p <.05) and at 5 days (6.3 +/- 2.0% vs. 20.2 +/- 1.2% in the nontreated group, p <.05). Monocyte tissue factor expression was significantly reduced at 5 days. CONCLUSIONS: These data indicate that potent inhibition of platelet function via antiglycoprotein-IIb/IIIa receptor blockade can inhibit coagulation activation and protect against endothelial dysfunction and histologic injury in endotoxin-induced shock.

Animals↗
PubMed2000

Basic fibroblast growth factor increases tissue factor expression in circulating monocytes and in vascular wall.

BACKGROUND: Basic fibroblast growth factor (bFGF) promotes vascular repair and angiogenesis and can induce in vitro tissue factor (TF), a potent agent initiating thrombogenesis, which probably plays a role in angiogenesis. We investigated whether bFGF administration induced TF expression by monocytes and vascular cells. METHODS AND RESULTS: We studied TF expression in normally fed (n=16) and cholesterol-fed (2% for 6 weeks, n=16) rabbits. Animals were then randomized to receive intravenous bFGF (2.5 microg twice weekly for 3 weeks) or saline injections. TF expression was evaluated in mononuclear cells from arterial blood and in aortic sections by an immunohistochemical assay using a monoclonal anti-rabbit TF antibody (activator protein 1). Monocyte TF expression was increased by bFGF administration in both normal and hypercholesterolemic rabbits (129+/-45 versus 19+/-3 mU TF/1000 monocytes, P<0.05, and 31+/-12 versus 7+/-1 mU TF/1000 monocytes, P<0.005, respectively) and was further increased by stimulation of monocytes by endotoxin in vitro. TF expression was lower in hypercholesterolemic rabbits than in normal rabbits. In the media of the vascular wall, bFGF induced strong TF expression in normal rabbits and only weak TF expression in hypercholesterolemic ones. CONCLUSIONS: This study demonstrates that systemic administration of bFGF induces an impressive increase of TF expression in circulating monocytes and in the vascular wall in normal and to a lower extent in hypercholesterolemic rabbits. The significance of this observation in terms of inducing thrombosis in vivo needs clarification.

Animals↗
PubMed2000

Differential role of nitric oxide pathway and heat shock protein in preconditioning and lipopolysaccharide-induced brain ischemic tolerance.

The purposes of this study were to investigate the role of nitric oxide (NO), nitric oxide synthase (NOS), and 70 kDa heat shock protein in brain ischemic tolerance induced by ischemic preconditioning and lipopolysaccharide. Focal cerebral ischemia was induced in rats by intraluminal middle cerebral artery occlusion. Infarct volume was significantly reduced (1) in rats subjected to 3 min ischemia 72 h prior to 60 min ischemia; (2) in rats administered lipopolysaccharide (0.5 mg/kg; i.p.) 72 h prior to 60 min ischemia compared with controls. The beneficial effect of ischemic preconditioning was unchanged despite prior administration of nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor. Conversely, the protective effect of lipopolysaccharide was nullified by L-NAME. Using immunohistochemical techniques, we observed that (1) ischemic preconditioning but not lipopolysaccharide induces the expression of 70 kDa heat shock protein in cerebral cortex and (2) lipopolysaccharide induces early increased expression of endothelial NOS in cerebral blood vessels. The results suggest that (1) endothelium-derived NO plays a role of a trigger in the brain tolerance induced by lipopolysaccharide, and (2) 70 kDa heat shock protein is involved in the protection afforded by ischemic preconditioning but not by lipopolysaccharide.

Animals↗