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Biomedical subjects

P de Vernejoul

Publications and source records attributed to P de Vernejoul.

At least 19 recordsLinked to original sources
PubMed1996

Assessment of reversible dyssynergic segments after acute myocardial infarction: Dobutamine echocardiography versus thallium-201 single photon emission computed tomography.

Only a moderate degree of concordance has been reported between stress-redistribution-reinjection thallium-201 single photon emission computed tomography (SPECT) and dobutamine echocardiography for the identification of myocardial viability after acute myocardial infarction. SPECT with rest-reinjection performed 4 hours after exercise testing and digitized two-dimensional (2-D) ultrasound reconstruction of the left ventricle at baseline and after low-dose dobutamine (5 to 10 microg/kg/min) infusion were compared in 50 patients > or = 8 days (12 +/- 7 days) after acute myocardial infarction. Five patients were excluded because of technically inadequate echocardiograms. Both SPECT and dobutamine echocardiography were assessed in a 16-segment model and interpreted in the remaining 45 patients. Digitized 2-D reconstruction of the left ventricle in each wall motion was scored from 1 (normal) to 4 (dyskinesia). Myocardial viability was identified on ultrasound wall-motion improvement of one or more grades from baseline to echocardiography performed > or = 30 days (60 +/- 41 days) after systematic revascularization procedure of the infarct-related artery. Reversible defect under thallium-201 SPECT and wall-motion improvement under dobutamine echocardiography were concordant in 163 (69 percent) of the 235 baseline dyssynergic segments and in 30 (67 percent) patients. Myocardial viability was identified after angioplasty (n=37) or surgery (n=8) in 29 patients and 109 segments. Positive and negative predictive values per patient in the diagnosis of myocardial viability were 86 percent and 57 percent, respectively, for stress thallium-201 SPECT with reinjection, and 100 percent and 62 percent for dobutamine echocardiography. Positive and negative predictive values per segment were 80 percent and 69 percent for the isotopic method and 91 percent and 70 percent for dobutamine echocardiography. We conclude that dobutamine echocardiography and stress thallium-201 SPECT with reinjection have similar accuracies to identify myocardial viability after acute myocardial infarction, with excellent positive but relatively low negative predictive values.

Adrenergic beta-Agonists↗
PubMed1996

[Tolerance of amlodipine in left ventricular dysfunction of ischemic origin].

The aim of this study was to assess the effects of amlodipine on left ventricular function at rest and on effort, at least 30 days after myocardial infarction. The 30 patients included in the study had resting isotopic ejection fractions of 40 to 60%. At inclusion and after 15 days treatment with 10 mg of amlodipine, the patients underwent exercise stress testing with a standard Bruce protocol and resting and exercise isotopic left ventricular ejection fractions were measured. The association of betablockers was allowed but vasodilator therapy was prohibited. During the second exercise stress test, the duration of exercise increased (437 +/- 167 to 518 +/- 154 s; p < 0.002) and the work level rose from 140 +/- 56 to 169 +/- 60 Watts; p < 0.04. The number of electrically positive tests did not change significantly (33 vs 26.7%; NS). The resting ejection fraction did not increase after 15 days treatment with amlodipine (47.4 +/- 6.7 vs 48.3 +/- 8.9%; NS). Similar results were observed with respect to the exercise ejection fraction (51.4 +/- 10.4 vs 52.6 +/- 8.6%; NS). These patients may however be divided into two subgroups. In the first subgroup of 10 patients, the resting ejection fraction rose by more than 5% with amlodipine whereas the exercise ejection fraction remained unchanged (54.4 +/- 7.7% vs 54.5 +/- 7.5% with amlodipine). In the second subgroup of 20 patients, the resting ejection fraction decreased slightly with amlodipine (48 +/- 6.9% vs 45.3 +/- 8%; p = 0.04) but increased significantly on exercise (45.3 +/- 8% vs 51.7 +/- 9.1%; p < 0.0002). Therefore, amlodipine, a new generation calcium antagonist, does not induce any deleterious effect after myocardial infarction with mild left ventricular dysfunction.

Adult↗
PubMed1994

Usefulness of radionuclide ventriculography during transesophageal atrial pacing in the diagnosis of coronary artery disease.

Radionuclide ventriculography before, during, and after atrial transesophageal pacing was carried out in 15 patients with suspected coronary artery disease (CAD) and without myocardial infarction. All patients underwent coronary angiography. Ten patients (group 1) had a coronary lesion > 50% on at least one of the main coronary arteries. Five patients (group 2) had normal coronary arteries. Radionuclide left ventricular ejection fraction (LVEF) before pacing was 56 +/- 3% in group 1 and 59 +/- 3% in group 2 (NS). Radionuclide ventriculography during pacing was 45 +/- 4% in group 1 (P < 0.0001 vs basal in group 1) and 45 +/- 6% in group 2 (P < 0.01 vs basal in group 2, NS vs group 1 during pacing). Immediate postpacing ejection fraction did not differ in the two groups and was identical to the prepacing value. A quantitative regional wall motion analysis was performed in 105 segments. Regional radionuclide ventriculography was calculated in each segment as follows: end-diastolic counts-end-systolic counts/end-diastolic counts. The relative decrease in regional LVEF during pacing was more important in the 39 segments related to a narrowed vessel than in the 66 segments related to normal coronary artery (32 +/- 13% vs 13 +/- 10%, P < 0.0001). A more than 20% relative decrease in at least one segment during pacing occurred in 10 patients in group 1 (sensitivity 100%) and in 2 patients in group 2 (specificity 60%). In conclusion, global radionuclide ventriculography during transesophageal atrial pacing decreases in patients with and without CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Value of linsidomine (SIN 1) in the evaluation of myocardial viability by 201-Tl scintigraphy after exertion].

201Tl scintigraphy can be used to determine exercise-induced ischemia and the viability of the hypoperfused myocardium as a function of radiotracer redistribution. Redistribution is calculated by differential analysis of the normalized circumferential curves of activity. Intravenous injection of linsidomine (SIN 1) a patent coronary vasodilatator, gives more reliable results than conventional imaging at the 4th h, and compares favourably with the results obtained at the 24th h after reinjection of 201 Tl. Linsidomine provides images in 60 to 90 min, in stable clinical conditions.

Adult↗
PubMed1989

[Measurement by isotope study of the cardiac output in the elderly].

Cardiac output and haemodynamic volumetric values (stroke volume, stroke index, left ventricular end-diastolic volume, blood volume, mean corpuscular volume and packed red cell volume) were measured in a population of 69 very old subjects (80 to 102 years) whose heart was regarded as normal on the basis of criteria determined, by radiocardiography and radionuclide ventriculography. These harmless and non-invasive techniques provided reference values in subjects of a seldom explored age group. Altogether, these values were lower than those of younger adults, and they decreased with age. Their reliability is due to the fact that they were obtained by true measurement and not by extrapolation of results observed in adults.

Age Factors↗
PubMed1987

Intracorneal correction of aphakia: paraxial approach at null incidence.

The technique of intracorneal implantation, recently proposed by de Laage de Meux and Cinquin [Implants, 2, 26 (1984)] for the correction of aphakia, is analyzed in terms of geometrical optics. The analysis is done by using matrix optics and by assuming a null incidence. The characteristics (diameter, radii of curvature, axial thickness) of the hard or soft lens to be implanted are determined and given. The aniseikonia of such lenses is shown to be nearly the same as that of contact lenses.

Aphakia↗
PubMed1987

Chronorhythms of the circulating erythrocytes and leukocytes--correlation with the E.S.R. cycles.

2750 healthy and fasting subjects, 20-30 years old, were studied over a half-year period in 1980. Considering the mean day value as a basic piece of information for statistics, the Erythrocyte Sedimentation Rate (E.S.R.) and the blood counts (erythrocytes, leukocytes, polymorphonuclears, lymphocytes, monocytes and eosinophils) were compared. The timeless relation between E.S.R. and each cell type number or percentage is rectilinear. The stronger slope and relation apply to the polymorphonuclears (PMN) or to the overall leukocytes. The chronological normalized variations of the E.S.R. and of the PMN or leukocyte number or percentage are highly correlated. E.S.R. is less correlated with monocytes, eosinophils and Lymphocytes. Contrary to what could have been expected, the erythrocyte situation is but an intermediate one. The spectra derived from the time variations show that all the cell types, whatever they are, are to be taken into account to explain the E.S.R. value and variation with time, even if, for a given cell type, the correlation and timeless relation were but faint ones. Each cell type has a specific spectrum. Erythrocytes are subject to low frequency variations (316-158 days). PMNs oscillate with time within the medium frequency range (90 days). Lymphocytes, monocytes and eosinophils fluctuate more quickly (53 days).

Adult↗
PubMed1987

[Circumferential analysis of digitalized gamma angiocardiography by assessment of regional left ventricular contraction].

After acquisition of a digital equilibrium gamma-angiocardiographie, circumferential analysis of end-diastolic and end-systolic frames gives 120 points diastolic and systolic curves. Their difference represents systolic volume and leads to regional left ventricular ejection fraction assessment at the considered radius level. The circumferential analysis evolute gives the regional left ventricular ejection fraction representative curves which allows especially differential diagnosis between left ventricular akinesia and dyskinesia.

Angiocardiography↗
PubMed1986

Evaluation of allograft perfusion by radionuclide first-pass study in renal failure following renal transplantation.

To assess the diagnostic value of indices measured on a first-pass curve, we performed 72 radionuclide renal first-pass studies (RFP) in 21 patients during the early weeks following renal allograft transplantation. The diagnosis was based on standard clinical and biochemical data and on fine needle aspiration biopsy (FNAB) of the transplant. Aortic and renal first-pass curves were filtered using a true low-pass filter and five different indices of renal perfusion were computed, using formulae from the literature. Statistical analysis performed on the aortic and renal indices indicated excellent reproducibility of the isotopic study. Although renal indices presented a rather large scatter, they all discriminated well between normal and rejection. Three indices have a particularly good diagnostic value. In the discrimination between rejection and Acute Tubular Necrosis (ATN), only one index gave satisfying results. The indices, however, indicate that there are probably ATN with an alternation of renal perfusion and rejection episodes where perfusion is almost intact. We conclude that radionuclide first-pass study allows accurate and reproducible quantitation of renal allograft perfusion. The measured parameters are helpful to followup the course of a post-transplantation renal failure episode and to gain more insight into renal ischemia following transplantation.

Acute Kidney Injury↗
PubMed1986

Pulmonary calcifications in children on dialysis.

Pulmonary calcifications are known to occur in patients with chronic renal failure. Recently, scintigrams with bone-seeking radionuclides have been used to detect subclinical pulmonary calcium deposits. We studied 18 children on maintenance dialysis without evidence of pulmonary calcification on chest X-ray. Four children (22.2%) had a positive technetium 99m hydroxymethylene diphosphate scan (group 1), and 14 children had a negative scan (group 2). Mean serum aluminum levels were 2.68 +/- 0.30 mumol/l (mean +/- SD) in group 1 as compared to 1.66 +/- 0.72 in group 2 (p less than 0.01). No significant difference was found between the groups with respect to serum levels of calcium, phosphorus, bicarbonate, magnesium and the calcium-phosphorus product as well as parathyroid hormone and vitamin D levels. The patients with pulmonary calcifications were on dialysis a significantly longer time than those of group 2 (62 +/- 15 versus 35.7 +/- 23 months; p less than 0.01). These data show that pulmonary calcification occurs with high frequency in children undergoing long-term dialysis. They seem to be related to high serum aluminum levels. We propose that pulmonary scintigrams with bone-seeking radionuclides be used routinely for the diagnosis and follow-up of uremic pulmonary calcification.

Adolescent↗
PubMed1986

Erythrocyte sedimentation rate of healthy subjects--chronological aspects.

Thanks to an elaborated mathematical approach, based on statistics and signal processing, the chronological changes of the Erythrocyte Sedimentation Rate (ESR) of young healthy subjects, considered from a collective point of view, have been discriminated into genuine and well-defined rhythms. These rhythms are tied up either to natural (year, season) or 'social' (month, week, holidays) cycles, or to some other causes, still unknown and possibly intrinsic (such is probably the case of a 26.5-day strongly marked period). The solar induced time variation strictly obeys a frequency modulation law, the relative amplitude of which is 10 per cent. Two axes of symmetry are found, centered on 8 August and 8 February. The rhythm is roughly in accordance with seasons. The modulation frequency is maximum at summer time. Oscillations of the ESR are observed during the week and the month. Fridays and the last fortnight of each month appear to be low ESR time.

Adult↗
PubMed1986

[Radioisotopic quantification of kidney function using Tc-99m-DMSA. Comparison with creatinine clearance in children with a single kidney].

To assess the accuracy of renal function quantification with Tc 99m-DMSA in children, we compared DMSA renal uptake and creatinine clearance in 16 cases of children with single kidney. The age of the patients ranged from two month to fourteen years. DMSA renal uptake was measured 7 hours after injection and was normalized in percent of the injected activity. A significant correlation was found between creatinine clearance and DMSA uptake (Pearson's r = 0.866, p less than 0.01). Normal creatinine clearance in children (80 to 120 ml/min-1 X 1.73 m-2) allowed determination of normal renal uptake (36 to 60%). This study indicates that in cases of asymmetrical renal impairment renal uptake reflects split renal creatinine clearance. Since the former is much easier to measure, DMSA should play an important role in the evaluation of differential renal function.

Adolescent↗
PubMed1985

[Evaluation of post-infarction disorders of left ventricular contraction by echocardiography and scintigraphy of the cardiac cavities].

The comparison in 36 patients of two-dimensional echocardiography and scintigraphy of the cardiac cavities in the steady state with left cineventriculography selective for the evaluation of anomalies in left ventricular contraction post infarction shows good agreement between these techniques for the detection of major segmental anomalies, a higher sensitivity being found for echocardiography in dyskinesis. The overall rejection fraction calculated by two-dimensional echocardiography is correlated with the ejection fraction calculated in left cineventriculography (r = 0.57; p less than 0.001). The same is true of the overall ejection fraction obtained by cavitary scintigraphy (r = 0.62; p less than 0.01). The indices of residual myocardium in the anterior wall (IRM ant) and the posterior wall (IRM post) calculated in apical echographic section for the two cavities and in left cineventriculography (oblique anterior right) are also well correlated (IRM ant: r = 0.70 and p less than 0.001; IRM post: r = 0.46 and p less than 0.01). The determination of these parameters as well as the percentage of shortening of the left ventricular small axis measured by echocardiography TM, to the smallest value, permits a valid assessment of ventricular function and makes it possible to avoid coronaroventriculography when this function is too impaired.

Adult↗
PubMed1984

[Antinuclear antibodies: analysis of images and classification of immunofluorescence aspects on nuclei isolated from rat hepatocytes].

Image analysis and Fourier transformation of the various nuclear immunofluorescence patterns observed while detecting antinuclear antibodies allow an objective and quantitative definition of the fluorescence. They also point out various IF types hidden by the main pattern, without having to dilute the test serum. They make obvious the difference between speckled and reticular patterns, and reveal the existence of intermediate states. The usual nuclear IF patterns (homogeneous, ring, nucleolar, reticulated, speckled and diffuse) may be grouped, according to their photo emission, into nuclear and subnuclear patterns. The first group includes homogeneous, annular and passive nucleolar IF. The second group is composed of speckled, reticulated, mixed, and active nucleolar IF. Alternatively, these aspects may be grouped into three types: homogeneous nuclear IF (homogeneous and ring), heterogeneous nuclear IF (speckled, reticulated and mixed) and nucleolar IF (active or passive). Diffusion can affect or not these aspects and does not apply to a special type or pattern. Image analysis and the study of the image spatial spectrum lead to automated recognition of the IF types, and later on, to the discrimination of antinuclear antibodies.

Animals↗