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Biomedical subjects

M C Plainfosse

Publications and source records attributed to M C Plainfosse.

At least 19 recordsLinked to original sources
PubMed1992

Vascular complications in the adult kidney transplant recipient.

Vascular complications of renal transplantation occurred in 15% of the cases. They are thrombotic infarct, arterial stenosis, arterio-venous fistula, and chronic arterial diseases. From 900 renal transplantations performed, only 120 (made since 1989) were studied with color flow Doppler (CFD). Lack of arterial signal is indicative of main arterial thrombosis (or of renal infarct if thrombosis is limited). At the site of arterial stenosis, high velocity and turbulence are found. If the stenosis is more than 70%, the rising systolic time is longer than 0.07 sec in the post-stenotic artery. Arterio-venous fistulas are frequent after renal biopsy. They provoke vibrations transmitted to peri-vascular tissues and seen with CFD as a large area of turbulence. In the feeding artery, Fast Fourier Transformation (FFT) showed a high velocity with a low resistive index and pulsed flow in the outgoing vein. Chronic arterial diseases include cyclosporine A intoxication and chronic rejection. These two diseases cannot be diagnosed by CFD alone.

Arteriovenous Fistula↗
PubMed1992

Serum Lp(a) as a discriminant marker of early atherosclerotic plaque at three extracoronary sites in hypercholesterolemic men. The PCVMETRA Group.

To investigate the role of lipoprotein (a) (Lp[a]) as an atherogenic condition related to hypercholesterolemia, we studied the serum concentration of Lp(a) as measured by immunonephelometry in relation to the presence of asymptomatic echographic plaques in the peripheral arteries of 103 untreated hypercholesterolemic, normotensive, middle-aged men. Plaque was found at carotid, aortic, and femoral sites in 36%, 51%, and 53% of subjects, respectively. The Lp(a) level was higher in the group with carotid plaques than in the group without (0.29 +/- 0.20 versus 0.17 +/- 0.14 g/l, p < 0.01), not significantly higher in the group with aortics plaque than in the group without (0.24 +/- 0.19 versus 0.19 +/- 0.16 g/l), and not different between groups with and without femoral plaques (0.21 +/- 0.18 versus 0.22 +/- 0.17 g/l). A logistic regression analysis confirmed that Lp(a) was associated with carotid plaques (p = 0.004), independent of other risk factors. However, in patients with low density lipoprotein cholesterol values above the group median value (4.7 mmol/l), Lp(a) was associated not only with carotid plaques (p < 0.01) but also with aortic plaques (p < 0.05), as well as with the number of diseased sites (p = 0.02). In contrast, in patients with low density lipoprotein cholesterol levels below or equal to 4.7 mmol/l, Lp(a) only remained associated with carotid plaques (p < 0.05). Thus, in symptom-free, hypercholesterolemic men, early atherosclerosis was influenced by serum Lp(a), particularly in the carotid arteries, as well as by the presence of a higher level of low density lipoprotein cholesterol.

Adult↗
PubMed1992

Coronary calcification and its relation to extracoronary atherosclerosis in asymptomatic hypercholesterolemic men. The PCV METRA Group.

BACKGROUND: The prevalence of coronary calcifications and extracoronary plaques was studied in patients with asymptomatic hypercholesterolemia. METHODS AND RESULTS: Ultrafast computed tomography for coronary calcification (presence or absence: calcium score) and echographic assessment of carotid, aortic, and femoral plaques were performed in 111 hypercholesterolemic men: 65% had coronary calcification, 72% had extracoronary plaque. The two lesions were associated as: 1) compared with subjects without coronary calcification, those with calcification had a higher prevalence of aortic (p less than 0.05) and femoral (p less than 0.01) plaque and of two diseased sites (p less than 0.05); 2) the prevalence of coronary calcification was higher in the presence than in the absence of aortic (p less than 0.05) or femoral (p less than 0.01) plaque and higher in two (p less than 0.01) and three diseased (p less than 0.05) sites than in no diseased site; 3) the calcium score was higher in the presence than in the absence of carotid (p less than 0.05), aortic (p less than 0.05), or femoral (p less than 0.001) plaque, higher in two (p less than 0.001) and three diseased (p less than 0.05) sites than in no diseased sites, and higher in two (p less than 0.01) than in one diseased site; and 4) the calcium score correlated with femoral plaque (p less than 0.001). Overall, the presence of two or three diseased extracoronary sites versus no or one diseased site showed a power of 78% for predicting coronary calcification. Coronary calcium score correlated with age (p less than 0.01) and triglycerides (p less than 0.05). CONCLUSIONS: The close relation between coronary calcium and extracoronary plaques suggests that echography of extracoronary vessels could aid in the screening of coronary atherosclerosis in high-risk, asymptomatic individuals.

Adult↗
PubMed1992

[Hypertension has no effect on coronary calcifications in asymptomatic patients with hypercholesterolemia].

Since calcium in coronary artery walls is considered as an indicator for atherosclerosis, we used ultrafast computed tomography to quantify it non invasively in 111 hypercholesterolemic men. They were selected at worksite by a cholesterol screening program, had total cholesterol (TC) above 5.2 (6.88 +/- 0.82, SD) mmol/l, were aged from 30 to 63 (46 +/- 5 years), had never been treated with lipid lowering or antihypertensive drug, and had no clinical coronary heart disease. Body mass index, blood pressure, smoking and other serum lipids as HDL cholesterol, triglyceride (TG) were evaluated. Calcium score of proximal coronary arteries was calculated on 30 contiguous 3 mm slices from areas and peak density of calcium lesions. The mean score was 30 +/- 69 and ranged from 0 to 440. A zero score was found in 39 subjects who differed from the 72 others only by TG levels (1.44 +/- 0.60 vs 1.85 +/- 0.80; p < 0.05). A multiple regression analysis showed that elevated calcium score was associated independently to age (F = 6.6; p < 0.05) and TG (F = 6; p < 0.05) but not to blood. Thus 65% of these asymptomatic subjects had a non-zero calcium score in coronary arteries. Elevated calcium score was influenced independently by age and triglyceride level, but not by other risk factors, such as blood pressure. This potential adverse effect of moderate triglyceride elevation on large coronary arteries merits attention in the assessment of the risk of coronary heart disease.

Adult↗
PubMed1991

[Reproducibility of Doppler measurements in renal circulation].

Duplex ultrasonography is now used to detect renal artery (RA) stenosis, but measurement reproducibility was not assessed systematically in renal circulation. Our aim was to definite intra and inter-observer variabilities of initial acceleration time (AT), peak systolic velocity (SV), and end-diastolic velocity (DV) in RA. We examined 12 hypertensive patients with angiographically normal RA and 2 normotensives. During these 14 explorations, all measurement were made by the operator A twice, and 13/14 times by the operator B twice. A duplex ultrasound CGR Radius CF* device was used with a 3.75 MHz probe. Once the RA spotted by color imaging, AT, SV, DV were measured by pulsed doppler aligning on arterial axis without angle correction with translumbar approach at different levels (distal trunk, hilus, sinus). SV intra-observer variabilities were for operator A on mean 30% at distal trunk, 3% at hilus, 4% at sinus; for B, there were respectively 16, 0, 2%. About DV, there were for A 3, 0, 1% and for B 2, 7, 0%. Reproducibility was worse about AT. SV inter-observer variabilities were 14, 2, 3%, for DV 13, 3, 2%, for AT 2, 6, 5%. Therefore indexes based on SV, DV, and AT with a less reproducibility may be used for screening or follow-up, but their diagnostic value is still to assess.

Adult↗
PubMed1991

Risk factors and early extracoronary atherosclerotic plaques detected by three-site ultrasound imaging in hypercholesterolemic men. Prévention Cardio-vasculaire en Médecine du Travail METRA Group.

Ultrasonic detection of atherosclerotic plaque of carotid abdominal aortic and femoral arteries and evaluation of risk factors were performed in 208 hypercholesterolemic men without cardiovascular disease. Twenty-six percent of them had no plaque. Plaque at the carotid, aortic, and femoral sites was found in 37%, 48%, and 53% of subjects, respectively. Plaque was associated (1) in carotid arteries with increased total and low-density lipoprotein cholesterol; (2) in the aorta with increased age, pressure, glycemia, and smoking; and (3) in femoral arteries with increased age, systolic pressure, low-density lipoprotein cholesterol, and smoking. Multiple regression analysis showed correlations between carotid plaque and low-density lipoprotein cholesterol; aortic plaque and age, smoking, glycemia, and pressure; femoral plaque and age, smoking, and pressure. This suggests that multiple risk factors influence lesions, and risk profile differs according to atherosis site.

Adult↗
PubMed1990

Relation of risk factors for cardiovascular disease to early atherosclerosis detected by ultrasonography in middle-aged normotensive hypercholesterolemic men. PCV Metra Group.

The relations between carotid arteries and/or abdominal aortic plaque and cardiovascular risk factors were investigated by ultrasonography in 161 untreated hypercholesterolemic normotensive men. Of them, 58 had no plaque (NP group), 34 had carotid but not aortic plaque (CP group), 34 had aortic but not carotid plaque (AP group) and 35 had both carotid and aortic plaques (CAP group). Groups significantly differed for age, smoking, blood pressure, and the ratio of total to HDL cholesterol. Age was higher in CAP group than in NP and CP groups and in AP and CP groups than in NP group. Life long smoking dose was higher in CAP group than in CP, AP, and NP groups. Systolic and diastolic pressures were higher in CAP group than in NP group, systolic pressure was higher in CAP group than in CP group, and diastolic pressure was higher in AP group than in CP and NP groups. The ratio of total to HDL cholesterol was higher in CAP group than in AP, CP, and NP groups. Multiple regression analysis showed that carotid plaque was only related to age, while aortic plaque and the number of sites affected by plaque were correlated to age, smoking and diastolic pressure. These findings suggest that in hypercholesterolemia risk factors other than lipids seem to influence arterial plaque and that risk profile differs according to the plaque location.

Adult↗
PubMed1988

[Contribution of microradiography in search of calcifications of valvular bioprostheses].

Implantation of a valvular bioprosthesis is one of the best treatments for valvular disease, particularly in children. Unfortunately, their use is limited as calcifications develop over time. Prevention of these calcifications is still an unresolved problem that is under study by Professor Carpentier and coworkers. These investigators have developed an experimental model in which accelerated development of calcifications occurs: fragments of porcine valves implanted under the skin of rats become calcified in a few days. Prior to implantation, the fragments are pretreated in an attempt to delay or prevent the development of calcifications. Two, four, six and eight months after implantation, the fragments are removed and calcifications are looked for using microradiography. Two hundred fragments have been studied. The material and technique used in our study are described. Results are semi-quantitative, based on the volume of calcifications. We conclude that microradiography is faster and more reliable than histology (the only technique used up till now) as it allows to study the entire fragments.

Animals↗
PubMed1988

[Indirect approach of stenosis of transplanted kidneys by Doppler echography].

Pulsed Doppler ultrasound for the detection of rejection and renal artery stenoses involving transplanted kidneys was evaluated. Using mean velocity curves, the time interval between the ECG R wave and the onset of peak velocity was measured successively on the renal and ipsilateral iliac arteries and divided by the R-R interval. In 27 patients, a Doppler index defined as the ratio of the standardized renal artery and iliac artery time intervals, was determined and compared to angiographic data. The DI index failed to detect stenoses associated with rejection; conversely, in the absence of rejection, clear separation of patients without (n = 14, DI = 1.03 +/- 0.6) and with (n = 6, DI = 1.24 +/- 0.05) stenosis (t = 7.48, p less than 0.001) was achieved. Thus renal artery stenoses in transplant recipients can be detected by the comparative study of time intervals calculated for renal vessels and for the neighbouring iliac artery.

Adult↗
PubMed1986

Ultrasound during surgery of the carotid artery.

Operative ultrasonography is very useful in carotid artery surgery--First to show before the reconstruction the site, the degree and the shape of the lesions--second after the reconstruction to appreciate its quality. In our 26 cases, reintervention was performed in five cases but only 3 have had a second reconstruction. Sensitivity of this method is very high, and this must be taken into consideration before any repeat surgery.

Carotid Artery Diseases↗
PubMed1986

Repetitive echoes in ultrasonography of the diaphragm demonstrated by cadaver studies.

For some years past, strange and seemingly inexplicable images frequently appear during sonographic examination of the area below the diaphragm. In order to explain these mysterious phenomena we carried out anatomical experiments. We observed the appearance of such enigmatic images no matter what the kind of probe was used and found that in every case the appearance of a phantom image over the diaphragm signifies the existence of a true image situated elsewhere. It is always possible with necessary adjustments to locate the formation responsible for the phantom images, which are no longer mysterious.

Diaphragm↗
PubMed1986

[Should colonic anastomoses be inspected radiologically?].

Routine early radiologic review examinations were conducted in 100 patients after colocolic or colorectal anastomosis. Postoperative course was assessed as clinically uncomplicated in 77 cases, a barium enema producing normal images in 67 and abnormal images in 10 cases, and recovery operations were not necessary. The course was more difficult in 23 patients: recovery operation to repair a gap was needed in 9 cases, while results were evaluated as satisfactory in 14 with 3 false negatives. Recovery operations (including 6 for fistula) in 9 patients followed acute clinical manifestations. Clinical evaluation is therefore of primary importance, a barium meal being justified only when intra-abdominal complications are suspected, while recognizing the risk of false negative results for this examination.

Aged↗
PubMed1985

Correlations between radiography, ultrasonography, computed tomography and pathologic findings in prostatic disease.

A total of 20 macroscopically normal or hypertropic prostates were taken from cadavers of men older than fifty, who died of causes other than urologic ones. The samples were studied in vitro by nonscreen x-ray films, ultrasonography, computed tomography, and then by a pathologist. There were 4 normal prostates, 12 with benign prostatic hypertrophy, 3 with carcinoma, and 1 with prostatitis. Conventional radiography which showed only prostatic calcifications was of no pathologic interest. Computed tomography is by no means of diagnostic use in distinguishing between benign prostatic hypertrophy and carcinoma, and should be used only as an alternative in the evaluation of regional extension of prostatic carcinoma. On the other hand, ultrasonography appears to be sensitive to detection of very small nonpalpable nodules. However, its specificity is poor and its use should be restricted as a guide in obtaining biopsy specimens or as a means of evaluating tumor volume.

Aged↗