Search PubMed⌕ Search

Biomedical subjects

P Dupont

Publications and source records attributed to P Dupont.

At least 19 recordsLinked to original sources
PubMed2006

A comparison of the effects of citalopram and moclobemide on resting brain perfusion in social anxiety disorder.

INTRODUCTION: The serotonin specific reuptake inhibitor (SSRI) citalopram and the reversible mono-amine oxidase-A inhibitor (RIMA) moclobemide have both been used successfully for the treatment of social anxiety disorder (SAD). In this study we investigate the effects of these compounds on resting brain function using single photon emission computed tomography (SPECT). METHODS: Subjects meeting DSM-IV criteria for SAD underwent regional cerebral blood flow (rCBF) SPECT using Tc-HMPAO at baseline and after 8 weeks of treatment with either citalopram or moclobemide. Using statistical parametric mapping brain SPECT studies were analysed to determine the effects of treatment on rCBF, to compare the effects of citalopram and moclobemide, and to detect correlations between changes in rCBF and clinical response. RESULTS: Subjects received citalopram (n=17) or moclobemide (n=14) as therapy. Subjects in both treatment groups demonstrated a significant improvement of SAD symptoms as measured by the Liebowitz Social Anxiety Scale total score. All subjects demonstrated a decrease in rCBF in the insulae post therapy. Subjects receiving citalopram had decreased superior cingulate rCBF after therapy compared to those receiving moclobemide. CONCLUSION: Both SSRI's and RIMA's decreased rCBF in the insulae during treatment of SAD; an effect that may be consistent with the role of these regions in processing internal somatic cues evoked by emotional stimuli. Citalopram had a greater effect on superior cingulate perfusion, an effect that is consistent with evidence of high levels of 5-HT transporters in this region.

Adult↗
PubMed2006

Correlations of interictal FDG-PET metabolism and ictal SPECT perfusion changes in human temporal lobe epilepsy with hippocampal sclerosis.

BACKGROUND: The pathophysiological role of the extensive interictal cerebral hypometabolism in complex partial seizures (CPS) in refractory mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS) is poorly understood. Our aim was to study ictal-interictal SPECT perfusion versus interictal fluorodeoxyglucose (FDG)-PET metabolic patterns. METHODS: Eleven adults with refractory unilateral mTLE-HS, who were rendered seizure free after epilepsy surgery, were included. All had an interictal FDG-PET and an interictal and ictal perfusion SPECT scan. FDG-PET data were reconstructed using an anatomy-based reconstruction algorithm, which corrected for partial volume effects, and analyzed semi-quantitatively after normalization to white matter activity. Using Statistical Parametric Mapping (SPM), we compared interictal metabolism of the patient group with a control group. We correlated metabolic with ictal perfusion changes in the patient group. RESULTS: Global cerebral grey matter glucose metabolism in patients was decreased 10-25% compared with control subjects. Interictal PET hypometabolism and ictal SPECT hypoperfusion were maximal in the ipsilateral frontal lobe. Ictal frontal lobe hypoperfusion was associated with crossed cerebellar diaschisis. The ipsilateral temporal lobe showed maximal ictal hyperperfusion and interictal hypometabolism, which was relatively mild compared with the degree of hypometabolism affecting the frontal lobes. CONCLUSION: Interictal hypometabolism in mTLE-HS was greatest in the ipsilateral frontal lobe and represented a seizure-related dynamic process in view of further ictal decreases. Crossed cerebellar diaschisis suggested that there is a strong ipsilateral frontal lobe inhibition during CPS. We speculate that surround inhibition in the frontal lobe is a dynamic defense mechanism against seizure propagation, and may be responsible for functional deficits observed in mTLE.

Adult↗
PubMed2006

Severity of primary MPGN, rather than MPGN type, determines renal survival and post-transplantation recurrence risk.

Previous studies suggested that membranoproliferative glomerulonephritis (MPGN) type II has a worse renal survival and an unacceptable risk of recurrence post transplantation. We hypothesised that other factors may determine this risk. We analysed all cases (n=70) of MPGN diagnosed by renal biopsy in Ireland from 1972 to 1995. We used Cox regression analysis to determine factors that were independently predictive of renal failure. MPGN II had more crescent formation and mesangial proliferation (P<0.05). Mean follow-up duration was 13.8 years, during which time 41 (58.6%) developed end-stage renal failure (ESRF). The median time to ESRF was 8.3 years (95% confidence interval 5.7-10.9) and 5-, 10-, and 20-year probabilities of ESRF were 32, 54, and 70%, respectively. Multivariate analysis revealed that severity of interstitial fibrosis (P<0.05), crescent formation (P<0. 01) and mesangial proliferation (P<0.05) were independently associated with ESRF. Decade of diagnosis, age, MPGN type, and creatinine or complement level at baseline did not predict renal survival in this model. In 21 (49%) of the 43 renal transplants, MPGN recurred. Younger age at initial diagnosis (P<0.01) and the presence of crescents on the original biopsy (P<0.005) were independently associated with recurrence on multivariate analysis. MPGN type was not associated with recurrence in this model. Contrary to previous reports, after controlling for crescent formation, MPGN II was not associated with more ESRF or recurrence in the allograft. It is therefore the more aggressive glomerular changes associated with MPGN II, rather than the disease type per se, that determine outcome.

Adolescent↗
PubMed2006

[Tricuspid valve endocarditis after umbilical piercing].

We report a case of a 16 years old girl who was affected by a septicemia with a septic arthritis of the wrist and a tricuspid endocarditis, 3 months after a navel piercing. The blood culture and the liquid of puncture showed Staphylococcus aureus. A treatment prolonged by intravenous antibiotics permitted a progressive regression of endocarditis, without surgical intervention. The piercing must be achieved in conditions of strict asepsis, it must be advised against to the patient with congenital heart disease. In case of realization of a piercing an antibiotic prophylaxis must be achieved, while using preference pristinamycin in case of cutaneous piercing and amoxicillin in case of mucous piercing. Indeed, infective endocarditis after body piercing are more often brought back with a generally sterner evolution that in our observation.

Adolescent↗
PubMed2005

[Low-level resistance to fluoroquinolones conferred by efflux overproduction in Pseudomonas aeruginosa: clinical significance and routine detection].

The aim of this study was (i) to assess the impact of stable overproduction of efflux systems MexAB-OprM and MexXY-OprM on the bacteriostatic activities of fluoroquinolones in clinical Pseudomonas aeruginosa strains and (ii) to find a convenient test for screening isolates with a low level resistance to fluoroquinolones. The minimal inhibitory concentrations (MICs) of ciprofloxacin and levofloxacin were determined for clinical isolates of P. aeruginosa overexpressing MexAB-OprM or MexXY-OprM. Efflux pumps derepression was associated with a modest two- to fourfold increase in resistance to the tested fluoroquinolones. Clinical significance of low level resistance conferred by the efflux mechanism was evaluated with a Monte Carlo simulation with various fluoroquinolone regimens. With this model, low levels of resistance to ciprofloxacin (MIC > or =0.25 mg/L) or levofloxacin (MIC > or =1 mg/L) such as those due to overproduced MexAB-OprM or MexXY-OprM were predicted to result in poor clinical outcomes. Altogether these data strongly suggest that when derepressed MexAB-OprM or MexXY-OprM provides P. aeruginosa with a resistance that may be sufficient to impair the efficacy of single therapy with highly potent fluoroquinolones such as ciprofloxacin and levofloxacin. Routine detection of clinical strains that displayed low-level resistance to fluoroquinolones with a Mueller Hinton agar containing 0.20 mg/L of ciprofloxacin will help clinician in his therapeutical choice.

Anti-Infective Agents↗
PubMed2005

[Acute myocarditis with Toxoplasma gondii. A case report in a newborn].

Acute myocarditis with Toxoplasma Gondii in immunocompetent patients is rare and the paediatric cases touch old children. These myocarditis lead sometimes cardiac insufficiency and sometimes mimic a myocardial infarction. The evolution is often favorable, even when there is no pest-destroying treatment. We report a case of myocarditis toxoplasma Gondii with which has occurred in a 11 month and half old infant, whose evolution was favorable with a symptomatic and pest-destroying treatment. The interest of this observation is related to the scarcity of acute myocarditis caused by toxplasmosis in infant without immunoinsufficiency.

Acute Disease↗
PubMed2004

Evaluation of hypoxia in an experimental rat tumour model by [(18)F]fluoromisonidazole PET and immunohistochemistry.

This study aimed to evaluate tumour hypoxia by comparing [(18)F]Fluoromisonidazole uptake measured using positron emission tomography ([(18)F]FMISO-PET) with immunohistochemical (IHC) staining techniques. Syngeneic rhabdomyosarcoma (R1) tumour pieces were transplanted subcutaneously in the flanks of WAG/Rij rats. Tumours were analysed at volumes between 0.9 and 7.3 cm(3). Hypoxic volumes were defined using a 3D region of interest on 2 h postinjection [(18)F]FMISO-PET images, applying different thresholds (1.2-3.0). Monoclonal antibodies to pimonidazole (PIMO) and carbonic anhydrase IX (CA IX), exogenous and endogenous markers of hypoxia, respectively, were used for IHC staining. Marker-positive fractions were microscopically measured for each tumour, and hypoxic volumes were calculated. A heterogeneous distribution of hypoxia was observed both with histology and [(18)F]FMISO autoradiography. A statistically significant correlation (P<0.05) was obtained between the hypoxic volumes defined with [(18)F]FMISO-PET and the volumes derived from the PIMO-stained tumour sections (r=0.9066; P=0.0001), regardless of the selected threshold between 1.4 and 2.2. A similar observation was made with the CA IX staining (r=0.8636; P=0.0006). The relationship found between [(18)F]FMISO-PET and PIMO- and additionally CA IX-derived hypoxic volumes in rat rhabdomyosarcomas indicates the value of the noninvasive imaging method to measure hypoxia in whole tumours.

Animals↗
PubMed2004

Dopamine transporter SPECT using fast kinetic ligands: 123I-FP-beta-CIT versus 99mTc-TRODAT-1.

A comparative study was carried out on two promising presynaptic dopamine transporter single-photon emission tomography (SPECT) radioligands with a fast pharmacokinetic profile, 123I-FP-beta-CIT (FP) and 99mTc-TRODAT-1 (TR), in order to assess their differential diagnostic power in early parkinsonism and their sensitivity for detection of disease progression. This cross-sectional study was conducted on 96 patients with early-stage parkinsonism referred in a tertiary clinical setting. Mean disease duration was 2.0+/-1.3 years, and patients had a modified Hoehn and Yahr (H&Y) stage of 1-2 (average 1.2). Forty-seven patients received TR, and 49 received FP. In both groups, ten patients with normal presynaptic function were included as a control population; all other patients were clinically diagnosed as having idiopathic Parkinson's disease. Groups were matched for gender, age, disease duration and modified H&Y stage. Triple-head gamma camera SPECT was analysed using a semiquantitative index of transporter binding (BI). Discriminant analysis with cross-validation resulted in a maximal classification accuracy for FP of 93% (sensitivity 95% and specificity 86%) for the contralateral putamen BI. For TR, the corresponding values were 87% accuracy, 92% sensitivity and 70% specificity. For FP, disease duration was correlated with both the putamen BI (-8.8%/year, rho=-0.41, P=0.025) and the putamen/caudate ratio (-7.4%/year, rho=-0.51, P=0.004), but for TR no significant correlation was found (all P values >0.5). In conclusion, both FP and TR show high sensitivity in a clinically relevant setting, but FP has superior accuracy for early differential diagnosis of idiopathic parkinsonism and non-degenerative extrapyramidal disorders, as well as better sensitivity for disease follow-up.

Aged↗
PubMed2004

[Delayed post effort muscle soreness].

Muscle intolerance to exercise may result from different processes. Diagnosis involves confirming first the source of pain, then potential pathological myalgia. Delayed-onset muscle soreness (DOMS), commonly referred as tiredness, occurs frequently in sport. DOMS usually develops 12-48 h after intensive and/or unusual eccentric muscle action. Symptoms usually involve the quadriceps muscle group but may also affect the hamstring and triceps surae groups. The muscles are sensitive to palpation, contraction and passive stretch. Acidosis, muscle spasm and microlesions in both connective and muscle tissues may explain the symptoms. However, inflammation appears to be the most common explanation. Interestingly, there is strong evidence that the progression of the exercise-induced muscle injury proceeds no further in the absence of inflammation. Even though unpleasant, DOMS should not be considered as an indicator of muscle damage but, rather, a sign of the regenerative process, which is well known to contribute to the increased muscle mass. DOMS can be associated with decreased proprioception and range of motion, as well as maximal force and activation. DOMS disappears 2-10 days before complete functional recovery. This painless period is ripe for additional joint injuries. Similarly, if some treatments are well known to attenuate DOMS, none has been demonstrated to accelerate either structural or functional recovery. In terms of the role of the inflammatory process, these treatments might even delay overall recovery.

Exercise↗
PubMed2004

Lipid and apoprotein changes during atorvastatin up-titration in hemodialysis patients with hypercholesterolemia: a placebo-controlled study.

BACKGROUND: Patients with end-stage renal disease commonly present with an atherogenic lipid profile characterized by the accumulation of triglyceride-rich, apoprotein B-containing "remnant" lipoproteins, small dense low-density lipoprotein, and low levels of high-density lipoprotein. They are at increased cardiovascular risk and may benefit from drastic lipid-lowering treatment with atorvastatin, a potent, broadacting lipid regulator. This study aims to assess the effects of atorvastatin on the lipid profile in hemodialysis patients, to determine wether atorvastatin is also effective at lowering lipid levels in this particular high-risk subgroup. METHODS: In this randomized, placebo-controlled, double-blind study in hemodialysis patients with hypercholesterolemia (n = 42, mean total cholesterol 243 +/- 33 mg/dl (6.3 +/- 0.8 mmol/l)), the efficacy of 4-weekly increasing doses of atorvastatin (10 - 40 mg daily) was investigated. Lipids and apoproteins were measured in plasma and isolated lipoprotein fractions. RESULTS: Mean total cholesterol and low-density lipoprotein cholesterol progressively decreased with increasing doses of atorvastatin (total cholesterol -33%, low-density lipoprotein cholesterol -43% after 12 weeks), while high-density lipoprotein cholesterol remained unchanged. Plasma levels of apoprotein B and apoprotein E were also significantly reduced by atorvastatin 10 mg, while up-titration to 20 and 40 mg daily provided additional benefits by lowering triglycerides and apoprotein C-III. At week 12, the fraction of small dense low-density lipoprotein was significantly reduced from 23% - 18%, and apoprotein B-containing intermediate-density lipoproteins were no longer detectable. CONCLUSION: In conclusion, atorvastatin not only treated hypercholesterolemia but also favorably affected the uremic lipid profile in patients on hemodialysis. Atorvastatin 4-weekly dose escalation up to 40 mg daily was well-tolerated. Further prospective studies are needed to evaluate the impact of this improved lipid profile on morbidity and mortality.

Aged↗
PubMed2003

18FDG-Positron emission tomography for the early prediction of response in advanced soft tissue sarcoma treated with imatinib mesylate (Glivec).

Imatinib mesylate (Glivec, formerly STI571) is the first effective systemic treatment for gastrointestinal stromal tumours (GISTs). Major changes in tumour volume, however, tend to occur late after the start of treatment. The aim of this study was to evaluate if [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) can be used for the early evaluation of response to imatinib mesylate treatment in soft-tissue sarcomas (STS). 21 patients (17 GIST, 4 other STS) underwent FDG-PET imaging prior to and 8 days after the start of treatment. PET response (European Organization for Research and Treatment (EORTC) guidelines) was observed in 13 GISTs (11 Complete Responders, 2 partial responders. Subsequent computerised tomography (CT) response Response Evaluation Criteria in Solid Tumours (RECIST) was observed in 10 of these patients after a median follow up of 8 weeks. Stable or progressive disease was observed on PET in 8 patients and none of them achieved a response on CT. PET response was also associated with a longer progression-free survival (PFS) (92% versus 12% at 1 year, P=0.00107). We conclude that FDG-PET is an early and sensitive method to evaluate an early response to imatinib treatment.

Adult↗
PubMed2003

Cerebral regions processing first- and higher-order motion in an opposed-direction discrimination task.

Using PET, we studied the processing of different types of motion in an opposed-direction discrimination task. We used first-order motion and two types of higher-order motion (presented as moving gratings with stripes defined by flickering texture and kinetic boundaries, respectively). In these experiments, we found that all types of motion activate a common set of cortical regions when comparing a direction discrimination task to a detection of the dimming of the fixation point. This set includes left hV3A, bilateral hMT/V5+ and regions in the middle occipital gyrus, bilateral activations in the posterior and anterior parts of the intraparietal sulcus, bilateral precentral gyrus, medial frontal cortex and regions in the cerebellum. No significant differences were observed between different types of motion, even at low statistical thresholds. From this we conclude that, under our experimental conditions, the same cerebral regions are involved in the processing of first-order and higher-order motion in an opposed-direction discrimination task.

Acoustic Stimulation↗
PubMed2003

SPECT perfusion changes during complex partial seizures in patients with hippocampal sclerosis.

Cerebral perfusion changes reliably reflect changes in neuronal activity. Our aim was to obtain new insights into the pathophysiology of complex partial seizures (CPS) in patients with hippocampal sclerosis (HS) using interictal and ictal single photon emission computed tomography (SPECT). We studied 24 patients with refractory temporal lobe epilepsy (TLE) associated with HS. All had an interictal and ictal SPECT with early injection during a CPS. Images were normalized and co-registered. Using statistical parametric mapping (SPM99), brain regions with significant ictal perfusion changes were determined. To assess possible interrelationships between these regions, Pearson correlation coefficients were calculated. The temporal lobe ipsilateral to the seizure focus, the border of the ipsilateral middle frontal and precentral gyrus, both occipital lobes and two small regions in the contralateral postcentral gyrus showed ictal hyperperfusion. The frontal lobes, contralateral posterior cerebellum and ipsilateral precuneus showed hypoperfusion. Further exploratory analysis suggested an association between ipsilateral temporal lobe hyperperfusion and ipsilateral frontal lobe hypoperfusion, and an inverse association between seizure duration and hyperperfusion in the ipsilateral anterior cerebellum and contralateral postcentral gyrus. We conclude that there is a network of perfusion changes during CPS in patients with HS. Studying a particular seizure type in patients with HS with peri-ictal SPECT performed during a defined time window will allow further analysis of the cerebral network activities, and excitatory, inhibitory and gating mechanisms during seizures associated with HS.

Adult↗
PubMed2003

De novo cryptogenic refractory multifocal febrile status epilepticus in the young adult: a review of six cases.

BACKGROUND: Status epilepticus (SE) is a common neurological emergency. In around 10 percent, the etiology of SE is not clear, i.e. cryptogenic SE. AIM: To describe six young adult patients with de novo cryptogenic multifocal febrile SE with poor outcome. METHODS: Retrospective chart review. RESULTS: We describe six patients who presented with de novo SE. All were young adults with an unremarkable previous medical history. In all except one, the family history for epilepsy was negative. All had a febrile illness in the week preceding SE. Investigations were unable to reveal the underlying etiology. SE proved refractory to conventional antiepileptic drug treatment (AED) and anesthesia was required to control seizures. Seizures during SE or ensuing epilepsy were multifocal. Brain pathology in four patients was normal in two and showed changes secondary to seizures in two. Outcome was poor in all cases: one patient died during the course of SE, another patient remained with severe mental and physical disability as well as refractory epileptic seizures, the other four developed refractory multifocal epilepsy. One of these patients died a sudden unexpected death in epilepsy (SUDEP) and one drowned during a seizure. CONCLUSIONS: Six patients were reviewed who presented with de novo cryptogenic multifocal refractory febrile SE. The possible etiologies are discussed. Based on the similarities in these cases, a distinct refractory SE syndrome might be assumed. Further prospective studies will, however, be required to validate this hypothesis as well as to elucidate its etiology and optimize treatment.

Adolescent↗
PubMed2002

[A new cause of false positives when analyzing expired air carbon monoxide].

INTRODUCTION: Measurement of expired air carbon monoxide expired is an essential examination to be conducted in smokers during consultation. However, this can be the source of errors, such as that identified in the case report we present here. OBSERVATION: A 65 year-old man, wishing to stop smoking, consumed a large quantity of polyol-rich sweets and exhibited increased expired air carbon monoxide levels, intestinal gases and increased volume of his liver. All these signs regressed when he stopped taking the sweets. COMMENTS: The production of intestinal gases related to polyol and isomalt contained in some products may be the cause of error in the measurement of expired air carbon monoxide.

Aged↗