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Biomedical subjects

P Cluzel

Publications and source records attributed to P Cluzel.

At least 55 records · Page 3Linked to original sources
PubMed1994

Nonpalpable breast tumors: diagnosis with contrast-enhanced subtraction dynamic MR imaging.

PURPOSE: To determine the accuracy of contrast material-enhanced subtraction dynamic magnetic resonance (MR) imaging in the diagnosis of nonpalpable breast tumors. MATERIALS AND METHODS: One hundred forty-three patients underwent surgical biopsy of a nonpalpable breast lesion. Their mammograms showed microcalcifications (n = 80), opacity (n = 52), architectural distortion (n = 10), or asymmetric density (n = 1). All patients underwent a preoperative gadolinium tetraazacyclododecanetetraacetic acid-enhanced subtraction dynamic study. Any early contrast enhancement in the breast parenchyma was considered pathologic. RESULTS: At histologic analysis, 27 intraductal carcinomas, 37 invasive carcinomas, and 79 benign lesions were found. Dynamic MR studies showed early contrast enhancement in 61 of 64 breast cancers (sensitivity, 95%) and in 37 of 79 benign lesions (specificity, 53%). Two invasive lobular carcinomas and one tubular carcinoma showed no early contrast enhancement. CONCLUSION: Subtraction dynamic MR imaging may be helpful to rule out malignancy in nonpalpable breast tumors.

Adult↗
PubMed1994

Stenoses of renal branch arteries in fibromuscular dysplasia: results of percutaneous transluminal angioplasty.

PURPOSE: To evaluate percutaneous transluminal renal angioplasty (PTRA) in the treatment of renal branch artery stenoses caused by fibromuscular dysplasia. MATERIALS AND METHODS: The authors retrospectively studied the files of 20 consecutive hypertensive patients with 25 branch artery stenoses associated with 10 main renal artery lesions. Results at clinical and angiographic follow-up were assessed by means of life-table analysis. RESULTS: PTRA was technically successful in 21 of the 25 renal branch artery stenoses (84%). One of the technical failures was treated by means of selective embolization. Nine of the 10 associated main renal artery lesions were successfully dilated, and the 10th was improved. Immediately after PTRA, at 6-month follow-up, and at long-term follow-up, 70%, 76%, and 68% of the patients, respectively, were cured and 25%, 24%, and 16% were improved. Stenosis recurred in 9% of the branch arteries and was associated with clinical relapse; these arteries were redilated, and all patients were considered cured at the second 6-month follow-up. CONCLUSION: PTRA should be considered the first-line treatment for hypertension due to renal branch artery stenosis in fibromuscular disease.

Adolescent↗
PubMed1994

[Sequencing of DNA by mechanical opening of the double helix: a theoretical evaluation].

We propose and evaluate a model experiment, in which the sequence of a DNA fragment is determined by mechanically opening the double helix in a controlled manner (e.g. pulling on the 3' end of one strand), and measuring the variation of the force exerted by the base pairs on a nanodynamometer (e.g. on a bead in an optical trap or a glass microneedle attached to the 5' end of the other strand). We show that the major limitation of the approach is the longitudinal elasticity of the already sequenced single strand sections, which soften the displacement-force function, and facilitate spontaneous thermal opening of the base pairs.

DNA↗
PubMed1993

High-resolution CT for specific diagnosis of diffuse chronic infiltrative lung disease.

High-resolution CT is highly contributive for correctly diagnosing chronic infiltrative lung disease, as it enables better interobserver agreement, it reveals more discriminant findings, and it provides complementary information. High-resolution CT should be considered an excellent extension to chest radiography and should be included in the routine investigation strategy of chronic infiltrative lung disease.

Humans↗
PubMed1992

Arteriovenous fistula of the internal maxillary artery in a child: case report.

Direct arteriovenous fistulae supplied by the external carotid artery are unusual. Rarely, congenital fistulae have been described involving the head and neck. We describe the first case of congenital internal maxillary arteriovenous fistula in a child. Balloon embolization is currently considered the method of choice for treatment of direct arteriovenous fistula.

Arteriovenous Fistula↗
PubMed1992

Pulmonary sarcoidosis: CT assessment of lesion reversibility.

By comparing serial computed tomographic (CT) scans obtained when sarcoidosis was clinically active and after the onset of remission, an attempt was made to differentiate inflammatory from fibrotic lesions in the lungs of patients with sarcoidosis. Twenty patients with pulmonary infiltration seen on their chest radiographs were studied. For each patient, lesions found on the first CT scan were assessed by two observers as being decreased or increased on the second CT scan. Nodules (n = 8), irregularly marginated nodules (n = 5), and alveolar or pseudoalveolar consolidation (n = 5) always disappeared or clearly decreased. Septal lines (n = 10), nonseptal lines (n = 9), and lung distortion (n = 7) remained unchanged or increased. Some findings varied among patients: Micronodules (n = 9) and subpleural thickening (n = 5) disappeared or decreased in sarcoidosis of recent origin. Many findings of pulmonary infiltration seen on the first CT scan can be considered expressions of either inflammatory (reversible CT findings) or fibrotic (irreversible CT findings) lesions.

Adolescent↗
PubMed1991

[Revascularization of occluded renal arteries. A case].

After recent treatment with an angiotensin converting enzyme inhibitor, a 62-year old woman with diabetes, hyperlipidemia and hypertension was admitted for oliguric acute renal failure due to bilateral renal artery lesions (right stenosis and left thrombosis). Hemodialysis was instituted. Percutaneous transluminal angioplasty (PTA) of the right renal artery did not improve the patient's condition, whereas left renal PTA, three weeks after admission, restored diuresis and renal function, allowing hemodialysis to be discontinued. This case underlines the capacity of functional recovery after late recanalization of a totally occluded renal artery. The best outcome predictor is the development of a collateral circulation and the visualization of distal renal arteries at arteriography. The kidney can be recanalized by surgery or PTA.

Angioplasty, Balloon↗
PubMed1991

[Contribution of imaging in the diagnosis of interstitial fibrosing lung diseases].

Standard radiography of the chest shows pulmonary infiltration and is determinant for the diagnosis of chronic diffuse infiltrative lung diseases. Since lung biopsy is an invasive exploratory technique, using computed tomography (CT) in the diagnostic approach is perfectly justified as a direct prolongation of plain radiography. CT identifies patients who, in spite of normal chest X-ray films, do have pulmonary infiltration. It is superior to radiography in suggesting the correct aetiological diagnosis, as it provides signs that are more discriminant than the radiographic signs. It also gives a better approach to the localization of lesions, thereby helping in guiding lung biopsies. Finally, once the diagnosis has been made CT remains useful in evaluating the effects of treatment of pulmonary lesions and in detecting possible complications.

Humans↗
PubMed1991

Chronic diffuse interstitial lung disease: diagnostic value of chest radiography and high-resolution CT.

The diagnostic value of chest radiography and high-resolution computed tomography (CT) in chronic diffuse interstitial lung disease (CDILD) was assessed in 140 consecutive patients with diffuse infiltration of the lung visible at radiography. Radiographs and CT scans were separately read by three independent observers without knowledge of clinical and pathologic data. The observers listed the three most likely diagnoses and recorded the degree of confidence they had in their choice on a 0%-100% probability scale. Findings at radiography and high-resolution CT were recorded by each observer and were used for a stepwise discriminant analysis between diagnoses. First-choice diagnoses of all three observers that were made with a high level of confidence (probability, greater than or equal to 75%) were more accurate with CT than with radiography (P less than .001). The superiority of high-resolution CT over radiography was most obvious for histiocytosis X and sarcoidosis; in cases of pulmonary fibrosis, CT was not significantly different from radiography. The interobserver agreement for the proposed diagnosis was significantly better with high-resolution CT (P less than .001). Twenty-one of 26 radiographic findings and 21 of 25 CT findings were discriminant. Stepwise discriminant analysis revealed the superiority of CT over radiography, since the ranking of all findings showed that the four most discriminant findings, and eight of the first 12 findings, were revealed with CT.

Adolescent↗
PubMed1991

[Percutaneous recanalization of renal arterial occlusion. Apropos of a case].

Percutaneous recanalization of a left occluded renal artery has been performed 10 days after percutaneous transluminal angioplasty of a controlateral renal stenosis. Improvement of the renal function is keeping normal 8 months after, although hypertension control is not very well. 26 case-reports have been found. These preliminary results are encouraging and suggest that this technique should be used against severe hypertension, especially if the kidney is functionnaly solitary, to avoid dialysis in patients with increased operative risk.

Acute Kidney Injury↗
PubMed1989

Predictive factors of the blood pressure fall induced by intravenous nicardipine.

The effect on blood pressure of the dihydropyridine derivative nicardipine was studied in 87 essential hypertensive patients aged 25-77 years. A total cumulative dose of 8.75 mg nicardipine was administered over a 30-min period by continuous intravenous infusion. The dose was doubled every 10 min from 1.25 to 5.0 mg. The mean blood pressure fall and the heart rate rise were both dose-related. At 30 min, mean blood pressure fell by 18.9 +/- 7.5% vs. baseline values (p less than 0.001), heart rate increased by 28.0 +/- 11.8% (p less than 0.001), and the renin level by 20.7 +/- 32.5% (p less than 0.001). The blood pressure fall was correlated positively with age (r = 0.521; p less than 0.001) and negatively with the rise in heart rate (r = -0.308; p less than 0.01) and renin level (r = -0.205; p = 0.05). After eliminating the linear effects of age by the partial correlation method, blood pressure fall and the initial renin level were no longer correlated (r = -0.046, NS), whereas the positive correlation between age and blood pressure fall persisted after eliminating the effect of renin (r = 0.464; p less than 0.001). The slope of the regression line for the heart rate rise vs. the blood pressure fall was taken to reflect the baroreflex sensitivity. This sensitivity was negatively correlated to age (r = -0.515; n = 51; p less than 0.001) in the 51 of the 87 patients for whom it could be calculated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[The kidney in Refsum's disease. Clinical, histologic and ultrastructural study of a case].

A renal biopsy was performed in a 41 year old man with Refsum's disease, following the onset of renal failure. 30% of the glomeruli were sclerosed, the others appeared normal. Ultrastructural examination revealed several types of inclusions within the tubular epithelial cells: dense bodies, simple or complex lipidic vacuoles and particularly structures composed of quadrangular microtubules with sides measuring 400 angstrom, rarely encountered in renal pathology. These dense elements, devoid of membrane and often in close contact with lipidic vacuoles, are found within the epithelial cells of the distal convoluted tubules and Henle's loops. They were localized extramitochondrially and no specimen was suggestive of a degraded form of the mitochondria. Some analogy can be made with the renal inclusions observed in Gaucher's disease.

Adult↗
PubMed1988

[Natural history of arterial hypertension due to primary hyperreninism].

This case report deals with an eight-year duration severe high renin hypertension and its consequences. In 1975, a 13 years old girl was found to have blood pressure (BP) levels of 240/150 mmHg with bilateral papilloedema. Hypokalemic alkalosis, a 45 mm Sokolow index (SI) and very high peripheral renin activity (PRA) were also noticed. Renal vein renin sampling (RVRS) suggested secretion from the left kidney but intravenous pyelography and renal arteriography were normal. BP levels were first controlled by triple treatment but rose one year later, despite adjunction of beta-blockers. High PRA was again found, but without hormonal gradient on a second RVRS. From 1977 to 1982, BP never fell to normal levels despite quadruple treatment. In 1982, a stage II optic fundus, a 58 mm SI and 2 g/day proteinuria are noticed, so that a new complete etiologic work up is undertaken in 1983: PRA is still high, with a dramatic acute BP fall after captopril and no gradient on a third RVRS, but intravenous pyelography, tomodensitometry and selective arteriography disclose a 4 cm diameter poorly vascularized tumour on the surface of the lower pole of the right kidney. BP levels are controlled for three months by captopril + chlorothiazide. The tumour is removed in january 1984. RVRS by direct peroperative punction indicates (a posteriori) hormonal secretion from the right kidney lower pole. Histologic examination and immunofluorescence with antirenin serum corroborate the juxtaglomerular origin of the tumour. Eighteen months later, BP is permanently normal, SI is 30 mm, and there is no proteinuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Muscle metastases: ultrasonic and x-ray computerized tomographic aspects. Apropos of 9 cases].

Clinical, ultrasound and CT scan examinations were carried out in 9 patients with secondary muscle lesions. All muscles can be affected but there was a marked predominance of psoas lesions (6 of the 9 cases). Two contrasting clinical pictures are seen. Secondary muscle tumors can occur during evolution of a known treated cancer (5 of the 9 cases), revealed usually by large, rarely painful, mass. CT scan imaging shows a heterogeneous mass taking up contrast and often partially necrotic, the lesions appearing hypoechogenic or heterogeneous on ultrasound examination. Certain lesions can be totally necrotic. In some cases (4 of the 9 patients) the muscle metastases revealed the presence of a tumor. Symptomatology may be atypical and lead to a delay in diagnosis. Fine needle puncture biopsy can detect the secondary origin of the muscle lesion and also the primary tumor site (4 out of 9 cases), bronchopulmonary and colon cancer predominating. Images are however non-specific and in the absence of NMR imaging the muscle or lymph node metastases can be confused, although this has no practice consequences since treatment is identical.

Adult↗
PubMed1987

[Evaluation of the biocompatibility of a new cellulose membrane by studying the complement system and histamine liberation].

This biocompatibility of the new cellulosic membrane hemophane (HE) is compared to that of cuprophane (CU) in ten maintenance hemodialysis (HD) patients dialyzed on the two types of membranes in randomized order, under otherwise similar technical conditions. Total white blood cell (WBC) and differential counts, blood concentrations of C3a, and C3d and histamine are determined at start of dialysis (TO) and 10, 20 and 180 minutes thereafter. HE is distinct from CU in exerting a minor effect on the generation of C3a, a minor drop of leucocytes during the course of dialysis (P less than 0.01) and also by a lesser increase in blood histamine concentration (P less than 0.05). Histamine liberation is observed on CU together with the generation of anaphylotoxin C3 and with a diminution of circulating basopolymorpho-nuclear cells. According to the variations observed for these three parameters (C3a, leucocytosis and blood histamine concentration), HE appears as being more biocompatible than CU.

Aged↗
PubMedDate not supplied

Percutaneous recanalization of recent renal artery occlusions: report of 10 cases.

PURPOSE: Percutaneous recanalization of renal artery occlusion was attempted in 10 patients. METHODS: All patients were hypertensive; before the procedure, the serum creatinine level was 80 mumol/L in one patient, ranged from 130-250 mumol/L in four patients, and was greater than 350 mumol/L in five, three of whom had anuria. Nine occlusions were thrombotic, one due to bilateral renal artery embolism. In four patients, percutaneous transluminal angioplasty of a contralateral renal artery occlusion was bilateral. In three patients, complementary local fibrinolysis was necessary. RESULTS: Three technical failures and one rethrombosis occurred after 24 h; in three of these cases the date of previous occlusion was unknown, whereas a relatively precise data was known for the seven other patients. One false aneurysm of the femoral artery was found 1 month after the procedure. One patient, after six technical successes, died 5 weeks after the procedure; follow-up for the other five was 6-36 months. Blood pressure was unchanged in four patients and improved in two. A significant and durable improvement of creatinine serum level (at least a 20% decrease) was observed in all six patients, usually after 1 month, thus enabling discontinuance of dialysis in three patients. CONCLUSION: Percutaneous recanalization should be proposed in cases of renal artery occlusion, especially to avoid terminal vascular azotemia and dialysis.

Adult↗