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R Sabatier

Publications and source records attributed to R Sabatier.

At least 19 recordsLinked to original sources
PubMed2004

Neuroanatomical localisation and clinical correlates of white matter lesions in the elderly.

BACKGROUND: White matter lesions (WML) in elderly people co-occur with hypertension, depression, and cognitive impairment. Little is known about the density and distribution of WML in normal elderly people, whether they occur randomly in the aging brain or tend to cluster in certain areas, or whether patterns of WML aggregation are linked to clinical symptoms. OBJECTIVES: To describe patterns of WML distribution in a large representative population of elderly people using non-inferential cluster analysis; and to determine the extent to which such patterns are associated with clinical symptomatology. METHOD: A population sample of 1077 elderly people was recruited. Multiple analysis of correspondence followed by automatic classification methods was used to explore overall patterns of WML distribution. Correspondence was then sought between these patterns and a range of cerebrovascular, psychiatric, and neurological symptoms. RESULTS: Three distinct patterns of spatial localisation within the brain were observed, corresponding to distinct clusters of clinical symptoms. In particular WML aggregation in temporal and occipital areas was associated with greater age, hypertension, late onset depressive disorder, poor global cognitive function, and overall WML frequency. CONCLUSIONS: WML localisation is not random in the aging brain, and their distribution is associated with age and the presence of clinical symptoms. Age differences suggest there may be patterns of progression across time; however, this requires confirmation from longitudinal imaging studies.

Aged↗
PubMed2002

Large intracoronary thrombi with good TIMI flow during acute myocardial infarction: four cases of successful aggressive medical management in patients without angiographically detectable coronary atherosclerosis.

Four cases of young patients with acute myocardial infarction are discussed in which urgent angiography showed large intracoronary thrombus and TIMI (thrombolysis in myocardial infarction) flow > or = 2 in the infarct related artery. The rest of the coronary tree appeared to be free of detectable atherosclerosis. Percutaneous transluminal coronary angioplasty was not performed and an aggressive antiplatelet/anticoagulant treatment was administered (acetylsalicylic acid, clopidogrel, abciximab, and heparin). In all cases early angiographic control (1-12 days after AMI) showed disappearance of thrombus, no significant residual stenosis, and normal flow. No deterioration of left ventricular function was observed and the clinical course both in hospital and at five months' follow up was uneventful.

Abciximab↗
PubMed2001

A method of age estimation using Raman microspectrometry imaging of the human dentin.

The aim of this work is to establish a correlation between ageing and Raman spectra imaging of human teeth. Raman spectrum of an analysed sample is characteristic of its chemical components. By exploring the different dentinal areas on each tooth, we sought to find a correlation between noticeable variability on Raman spectra and the stages of dentinal evolution with advancing age. A study on 30 teeth analysed by Raman microspectrometry was used to select predictors of age, and it allowed us to determine a regression formula, with age as a dependent variable. Our data were computed by means of a statistical method called partial least squares (PLS) regression. This method was specially adapted for this kind of situation, where we have numerous predictors and relatively few observations. The regression formula was performed on a test sample of four more teeth, and we obtained a correct age estimation, with a mean error of more or less than 5 years. The main benefits of this method was a minimal and non-destructive tooth preparation, which led to an efficient age prediction, for any age group.

Adolescent↗
PubMed2001

Comparison of direct coronary stenting with and without balloon predilatation in patients with stable angina pectoris. BET (Benefit Evaluation of Direct Coronary Stenting) Study Group.

The purpose of this study was to compare the effects of stent placement with and without balloon predilatation on duration of the procedure, reduction of procedure-related costs, and clinical outcomes. Although preliminary trials of direct coronary stenting have demonstrated promising results, the lack of randomized studies with long-term follow-up has limited the critical evaluation of the role of direct stenting in the treatment of obstructive coronary artery disease. Between January and September 1999, 338 patients were randomly assigned to either direct stent implantation (DS+; 173 patients) or standard stent implantation with balloon predilatation (DS-; 165 patients). Baseline clinical and angiographic characteristics were similar in the 2 groups. Procedural success was achieved in 98.3% of patients assigned to DS+ and 97.5% of patients assigned to DS- (p = NS), with a crossover rate of 13.9%. Compared with DS-, DS+ conferred a dramatic reduction in procedure-related cost ($956.4 +/- $352.2 vs $1,164.6 +/- $383.9, p <0.0001) and duration of the procedure (424.2 +/- 412.1 vs 634.5 +/- 390.1 seconds, p < 0.0001). At 6-month follow-up, the incidence of major adverse cardiac events including death, angina pectoris, myocardial infarction, congestive heart failure, repeat angioplasty, or coronary artery bypass graft surgery was 5.3% in DS+ and 11.4% in DS- (p = NS). Multivariate analysis demonstrated that major adverse cardiac events rates were related to stent length of 10 mm (relative risk [RR] 3.25, 95% confidence intervals [CI] 1.36 to 7.78; p = 0.008), stent diameter of 3 mm (RR 2.69, 95% CI 1.03 to 7.06; p = 0.043), and complex lesion type C (RR 2.83, 95% CI 1.02 to 7.85; p = 0.045). Thus, in selected patients, this prospective randomized study shows the feasibility of DS+ with reduction in procedural cost and length, and without an increase in in-hospital clinical events and major adverse cardiac events at 6-month follow-up.

Angina Pectoris↗
PubMed2001

Initial and follow-up results of the Tenax coronary stent.

The Tenax coronary stent is laser sculpted from high precision 316 L stainless steel using advanced production procedures. An a-SiC: H (hydrogen-rich amorphous silicon carbide) coating reduces its thrombogenicity and improves its biocompatibility. From April to July 1998, 266 stents were implanted in 241 patients (aged 62.7 +/- 10.5 years) in five centers. The clinical indication for intervention was unstable angina (33.2%) and recent myocardial infarction (29.5%) in many cases. Most lesions (53.8%) had complex characteristics (Class B2 or C). The target vessel was the LAD in 42.5% and the right coronary artery in 36.8% of all cases. Four primary stent deployment failures occurred and implantation was successful in 259 (97.4%) of 266 stents. No death and no Q-wave myocardial infarction or emergency CABG occurred during hospital stay. Clinical success, defined as successful deployment without procedural or clinical event, was achieved in 230 (95.4%) of 241 patients. One-year clinical follow-up shows a low need for target lesion revascularization (17/237 [7.1%] patients) and a 15.8% rate of major adverse cardiac events (36/237 patients). The clinical and angiographic outcomes of our study suggest that the hybrid, amorphous hydrogenated silicon carbide coated design is promising and merits further evaluation in larger clinical trials.

Aged↗
PubMed2000

In vitro detection of indirect-acting genotoxins in the comet assay using Hep G2 cells.

The induction of DNA damage by four known promutagens (cyclophosphamide (CP), benzo(a)pyrene (BP), dimethylbenz(a)anthracene and 2-acetylaminofluorene (2AAF) was investigated on Hep G2 using the alkaline single cell electroporesis (SCGE) test, most often referred as the "comet assay". After a 3-day incubation, lysed cells embedded in agarose were electrophoresed under alkaline conditions, dyed with a SYBRgold fluorogen and analysed by the Komet software. Among the comet parameters provided by the image analysis program, statistical analysis did not identify any in particular that could best represent the DNA damages. All promutagens, when compared with the control, caused a statistically significant increase in DNA migration as determined by different parameters such as Olive tail moment, tail extent moment, tail/head or tail length. The data demonstrated the ability and the sensitivity of the comet assay when performed on Hep G2 in the detection of DNA damage induced by promutagens, and its suitability in mutagenicity testing in in vitro short-term assays.

2-Acetylaminofluorene↗
PubMed1999

Tau and apo E in CSF: potential aid for discriminating Alzheimer's disease from other dementias.

To evaluate the usefulness of tau proteins as biological markers in the diagnosis of dementia of the Alzheimer type (DAT), we analyzed the concentration of tau proteins in 253 cerebrospinal fluid (CSF) samples from patients with or without neurological disorders. Our study showed a significant increase of the mean CSF tau concentration in DAT patients compared with that from non-DAT patients. Interestingly, a significative decrease of CSF tau in patients with frontotemporal dementia was found. We also observed a positive correlation between the CSF-tau concentration and the number of apoepsilon4 alleles. The CSF apolipoprotein E concentration was evaluated and revealed no variation between the groups, although we observed a significant correlation between CSF tau and apolipoprotein E in DAT patients.

Age Factors↗
PubMed1999

Direct coronary stenting without balloon predilation in acute coronary syndromes.

BACKGROUND: This prospective, observational study was designed to evaluate the feasibility and the safety of a new strategy for stenting in acute coronary syndromes: direct stent implantation without predilation of the culprit lesion. This strategy might reduce both the cost of the procedure and the rate of no-reflow, a phenomenon that is more frequently observed during dilation of unstable plaques. METHODS AND RESULTS: Between September 1997 and March 1998, 122 carefully selected patients with unstable angina or acute myocardial infarction were included in this study. Highly calcified lesions and vessels with excessive proximal tortuosity were excluded. The procedure was successful in 96% of cases. In 5 cases the stent failed to pass through the stenosis and was successfully retrieved in the guiding catheter in 3 cases. In 2 cases the stent was lost in the peripheral circulation. Transient no-reflow occurred in only 3 cases and was rapidly reversed by rescue use of an intracoronary bolus injection of a glycoprotein IIb/IIIa receptor inhibitor in 2 cases. A patient treated by primary angioplasty with cardiogenic shock on admission died 48 hours after the initial procedure because of irreversible cardiac failure. One-month clinical follow-up was obtained by telephone for all patients; no major coronary events occurred during this period. CONCLUSIONS: Direct coronary stenting without balloon predilation can be safely performed in acute coronary syndrome-related lesions in selected patients. A randomized, controlled study is warranted to confirm the promising results of this pilot study, especially regarding the low rate of the no-reflow phenomenon.

Aged↗
PubMed1999

A new approach for clinical biological assay comparison and standardization: application of principal component analysis to a multicenter study of twenty-one carcinoembryonic antigen immunoassay kits.

BACKGROUND: Principal component analysis (PCA) is a powerful mathematical method able to analyze data sets containing a large number of variables. To our knowledge, this method is applied here for the first time in the field of medical laboratory analysis. METHODS: PCA was used to evaluate the results of a blind comparative study of 21 carcinoembryonic antigen (CEA) reagent kits used to determine CEA concentration in a panel of sera from 80 patients. RESULTS: The mathematical technique first eliminated the variations attributable to the use of different calibrators. The PCA representation then gave a global view of the dispersion of the kits and allowed the identification of a main homogeneous group and of some discrepant kits. CONCLUSIONS: PCA applied to the in vitro diagnostic reagent field could contribute to the standardization process and improve the quality of medical laboratory analyses. A standardization method using a panel of patient sera is proposed.

Biomarkers, Tumor↗
PubMed1993

Dose-related effect of moxisylyte on maximal urethral closing pressure in patients with spinal cord injuries.

The effects of single intravenous doses of 0.25, 0.50, and 0.75 mg/kg moxisylyte on maximum urethral closure pressure were evaluated in a placebo-controlled double-blind experiment in 20 patients with spinal cord injuries. Pharmacodynamic testing was performed until 30 minutes, and blood pressure was assessed until 60 minutes. Our findings showed a dose-dependent decrease in maximum urethral closure pressure. At each individual time point, the three doses differed significantly from placebo. Ten minutes after dose administration the maximum effect (48% decrease) was obtained with 0.75 mg/kg. A significant difference in favor of the highest dose was shown from 15 to 20 minutes after administration. According to these findings and because 0.75 mg/kg was as well tolerated as the two other doses, such a drop in pressure indicates that the alpha-blocking agent moxisylyte may be an effective means of decreasing urethral resistance, with obvious implications for the management of urinary obstruction.

Adolescent↗
PubMed1993

Inhibition of gastric acid secretion by oxyntomodulin and its 19-37 fragment in the conscious rat.

Oxyntomodulin (Oxm) is a hormone, released from the intestine during digestion. Its target tissue is the gastric mucosa, where it inhibits acid secretion. It contains the 29-amino acid glucagon moiety, extended at its COOH-terminal end by an octapeptide. The glucagon moiety contains a basic doublet (Arg17-Arg18). Our working hypothesis was that the mode of action of Oxm may imply a processing of the molecule at the Arg-Arg doublet, releasing Oxm-(19-37). We compared the effect of Oxm with that of Oxm-(19-37) on gastric acid secretion in the conscious rat provided with a chronic gastric fistula. The acid secretion was plateau stimulated by a perfusion of either pentagastrin or histamine. Whereas Oxm or Oxm-(19-37) had no effect on basal acid secretion, both peptides inhibited pentagastrin (0.5 micrograms.kg-1.h-1)- and histamine (0.4 mg.kg-1.h-1)-stimulated acid secretion in a dose-dependent manner. When the metabolic clearance rate for each peptide was taken into account, the 19-37 fragment was as potent as the whole Oxm, regardless of the type of stimulant. When the dose of pentagastrin was increased from 0.175 to 1.1 micrograms.kg-1.h-1, the extent of inhibition induced by Oxm (40 pmol/kg) also increased. In contrast, when the dose of histamine was increased from 0.25 to 1.2 mg.kg-1.h-1, the extent of inhibition induced by Oxm (40 pmol/kg) decreased. Oxm-(19-37) (70-140 pmol/kg) displayed the same behavior as the whole molecule under both types of stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

HIV: a testing dilemma.

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Acquired Immunodeficiency Syndrome↗
PubMed1988

AIDS: is race an issue?

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Acquired Immunodeficiency Syndrome↗