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Biomedical subjects

A Raynaud

Publications and source records attributed to A Raynaud.

At least 55 records · Page 3Linked to original sources
PubMed1993

Restenosis after a first percutaneous transluminal renal angioplasty.

The incidence of restenosis after a first successful percutaneous transluminal angioplasty of a native renal artery and the clinical and angiographic variables that may influence its occurrence were studied in 104 hypertensive patients. Angiograms obtained immediately before and after angioplasty and, in 92 patients, 8.8 +/- 6.0 months after angioplasty were interpreted separately by two observers. Stenosis severity was classified into five grades, and restenosis was defined by a stenosis one grade or more higher at follow-up than immediately after angioplasty. Interobserver concordance for etiology, stenosis grade, and other angiographic items yielded kappa coefficients in the range of 0.328-0.942. Sessions were organized to reach a consensus in each case. Ostial stenoses were more frequent in patients with atheromatous stenoses, and branch stenoses were more frequent in those with fibromuscular dysplasia. There was no significant difference between the 15 patients (16%) with restenosis and those without concerning sex distribution, mean age, mean blood pressure, plasma creatinine level, and etiology distribution. Truncal stenoses were less prone to restenosis than ostial or branch stenoses (12% versus 35%, respectively; 95% confidence interval of difference, -0.6% to 47%). In patients with atheromatous stenoses, aortitis or aortic ectasia were associated with a high restenosis incidence (35% when present versus 8% when absent; 95% confidence interval of difference, 5% to 48%). In conclusion, restenosis was observed in one sixth of patients after a first successful renal angioplasty; its incidence was low in patients with truncal stenoses and high in those with severe aortic atheroma. Automated renal artery stenosis quantification methods are needed to standardize stenosis description.

Adult↗
PubMed1992

[Renovascular arterial hypertension. Evaluation of ultrasonographic measurement of kidney length].

In order to evaluate the ultrasonographic measurement of kidney length, 32 hypertensive patients with renal arterial stenosis treated by intraluminal angioplasty were examined by several ultrasonographies performed by the same observer before and after dilatation. The lack of variation in the contralateral kidney length ascertained the intra-observer reproducibility of the method. We found that ischaemic kidneys were smaller and that this diminution in size depended on the renal arterial lesion (kidneys below atheromatous lesions were of smaller size than those below fibrodysplastic lesions). The increase in size of kidneys treated by angioplasty was most probably due to an increase in perfusion pressure and was to be compared with the results of a separate evaluation of renal function. However, this method has no individual applications in view of the important kidney length distribution at cross-checkings.

Adult↗
PubMed1992

DNA synthesis decline involved in the developmental arrest of the limb buds in the embryos of the slow worm, Anguis fragilis (L.).

The present study was carried out to try and detect the biochemical mechanism involved in the developmental arrest of the limb bud in a serpentiform Reptile. Autoradiograpy, following tritiated thymidine incorporation, in embryos of the slow-worm (Anguis fragilis, L.) reveals a strong decrease in the rate of DNA synthesis in the mesodermal cells of the limb bud, after the degeneration of the apical ectodermal ridge (AER); the curve (a function of Gompertz) visualizing this decline shows that the drop in DNA synthesis becomes accentuated just after the degeneration of the AER. This decrease precedes the reduction of the mitotic index, the cell degeneration in the mesoderm and the other regressive changes occurring in the limb bud; it thus appears as the main causative factor of the developmental arrest of the limb bud. Furthermore, these results suggest that one of the functions of the AER would be to maintain a high level of DNA synthesis in the mesoderm underlying the AER in a normal limb bud.

Animals↗
PubMed1991

Selective venous catheterization in the evaluation of hyperandrogenism.

Retrograde bilateral ovarian-adrenal vein catheterization was carried out in 16 patients with plasma testosterone levels exceeding 1.4 ng/ml (4.85 nmol/l). While pelvic ultrasonography and computerized axial tomographic scan failed to locate the androgen-producing ovarian tumors, catheterization led to a diagnosis of occult ovarian tumor in 5 patients, based on the observation of an abnormally-high and unilateral ovarian-peripheral vein testosterone gradient, which was subsequently confirmed histopathologically. In one case, unilateral elevation of the adrenal-peripheral vein testosterone gradient was found, complementing the ultrasonographic finding of an adrenal mass and confirming the diagnosis of a virilizing adrenal tumor. In the other 10 patients, gradient analysis ruled out an androgen-producing tumor, leading to the identification of nontumoral hyperandrogeny, such as a severe form of the polycystic ovary syndrome in the 6 premenopausal patients and of ovarian stromal and hilus cell hyperplasia in the 4 menopausal patients. In conclusion, appropriate indication of selective catheterization may considerably reduce the need for exploratory surgery and may help in selecting the adequate surgical approach.

Adrenal Gland Neoplasms↗
PubMed1991

Iliac artery stenosis or obstruction after unsuccessful balloon angioplasty: treatment with a self-expandable stent.

Obstruction or stenosis of the iliac artery was treated by placement of a self-expandable stent in 91 patients. A total of 100 lesions was treated. All patients had had poor results of balloon angioplasty including residual stenosis, iliac occlusion, and dissection. The stent used in all cases was a self-expandable stainless steel endoprosthesis mounted on a 7- or 9-French catheter and covered by an invaginated tubular rolling membrane. The diameter of the expanded stent varied from 7 to 12 mm. A total of 129 stents was placed. Technical success was 97%. Thromboses occurred immediately after placement in two patients and within the first month in six; these were mainly due to residual obstruction. Eighty-two (93%) of 88 patients with a follow-up longer than 3 months had no recurrent symptoms. Restenosis caused by intimal hyperplasia inside the stent occurred in 10 patients; these required repeated intervention in only four cases. In the remaining six patients, no further complications occurred. Our results show that self-expanding endoprostheses are of value for improving the results of inadequate percutaneous transluminal angioplasty.

Adult↗
PubMed1990

[Intraluminal angioplasty in renovascular arterial hypertension. 104 cases].

Between January 1, 1985 and January 1, 1988, 104 patients with arterial hypertension and renal artery stenosis were treated by percutaneous transluminal angioplasty (PTA). The procedure was justified by the resistance of hypertension to other treatments in 50 patients with atheromatous stenosis and 38 patients with fibrodysplasic stenosis. In the remaining 16 patients, who had severe atheroma, PTA was made necessary by ischaemic renal failure. Out of 52 PTAs (including 2 bilateral in one stage) performed in atheroma patients without renal failure, 48 (92 per cent) were immediate technical successes. In 44 patients arterial pressure measurements after 7.5 months (2-24) showed cure in 6 cases (13 per cent), improvement in 29 cases (66 per cent) and failure in 9 cases (21 per cent). Control arteriography of 40 arteries showed success in 28 cases (70 per cent), residual stenosis in 9 (22 per cent) and restenosis in 3 cases (8 per cent) (2 secondary successes of PTA). In patients with fibrodysplastic stenosis, 42 PTAs (4 bilateral) resulted in immediate angiographic success in 81 per cent. In 34 patients arterial pressure measurements after 8.2 months (2-35) showed cure in 2 cases (65 per cent), improvement in 10 cases (29 percent) and failure in 2 cases. Angiography of 34 arteries showed success in 31 (91 per cent) and restenosis in 3 (2 bypasses). In 13 of the 16 patients with renal failure, the renal function was stabilized by PTA, but 5 patients needed surgery and 2 were put on chronic dialysis. It is concluded that the immediate and medium term success rates of renal angioplasty confirm the value of this recanalization procedure in fibrodysplasia and atheroma.

Adult↗
PubMed1990

[Value and limits of renal artery examination in the aged].

We compared the efficacy and safety of percutaneous renal angioplasty for the treatment of renovascular disease in younger (aged less than 60) and elderly patients (aged 60 or more). Angioplasty yielded a higher technical success rate in younger patients while complications occurred more frequently in the elderly. Among patients with a successful angioplasty, the rate of cure or improvement of hypertension tended to be higher in the younger patients. The efficacy and safety of renal artery angioplasty may be limited in elderly patients by age-associated atheroma of renal and extra-renal arteries.

Aged↗
PubMed1990

Developmental mechanism involved in the embryonic reduction of limbs in reptiles.

The purpose of the studies here reported was to explain the mechanisms responsible for the reduction of limbs in the serpentiform reptiles. Descriptive and experimental embryology, ultrastructural studies, chemical action (with Ara-C) on embryos and (3H) thymidine autoradiography of limb buds were used in this study; they provide evidence that defects in the morphogenetic mechanisms involved in the development of limbs (somitic deficiency, incomplete differentiation and premature degeneration of the apical ectodermal ridge) are responsible for the cessation of growth of the limb buds in these reptiles. At the biochemical level, a strong decline in the rate of DNA synthesis in the mesodermal cells of the limb bud (during and after the degeneration of the apical ridge) is the main causative factor of the evolutionary arrest of limb development in serpentiform reptiles.

Animals↗
PubMed1989

Influence of age on the outcome of percutaneous angioplasty in atheromatous renovascular disease.

We compared the efficacy and safety of percutaneous transluminal renal angioplasty for the treatment of renovascular disease in 66 patients. Thirty-four were aged less than 60 years, and 32 more than 60 years. The younger patients had a shorter known duration of hypertension and higher levels of diastolic pressure (6.4 +/- 9 years and 109 +/- 15 mmHg) than the older patients (12.8 +/- 8 years and 101 +/- 11 mmHg, P less than 0.01 for both comparisons). They also had higher creatinine clearance rates (78 versus 46 ml/min, P less than 0.01) and less severe renal artery disease. A total of 70 percutaneous transluminal renal angioplasties were performed in 70 arteries with a technical success rate of 100% in the younger group versus 67% in the older group (P less than 0.01); complications occurred more frequently in the older group. Our data indicate that, when technically successful, percutaneous transluminal renal angioplasty improves blood pressure to a similar extent in both younger and older patients. However, in patients over 60 years, the safety of the procedure is limited by more severe age-associated atheroma of renal and extrarenal arteries.

Aging↗
PubMed1988

[Transluminal angioplasty in renovascular hypertension with renal insufficiency].

From 1985 to 1986, 71 patients with renovascular hypertension were treated by percutaneous transluminal angioplasty (PTA). Among them, 13 (mean age 67 +/- 7 years) had a hypertension refractory to drug therapy (blood pressure: 194 +/- 33/103 +/- 15 mmHg) associated with an impaired renal function (creatinine clearance: 33 +/- 20 ml/mn). Ten had a stenosis in a solitary functioning kidney and a contralateral renal artery thrombosis. Three had bilateral renovascular stenosis. All patients had severe diffuse atherosclerotic disease, i.e. coronary heart disease (n = 7), carotid artery stenosis (n = 6), abdominal aortic aneurysm (n = 3) or arteritis (n = 5). Among these 13 patients, PTA could not be performed in one patient (failure to catheterize the stenosis) and two immediate renal artery dissections were observed: the first was accompanied by a thrombosis of the renal artery which could be successfully treated in emergency by surgical revascularization. The second occurred in a segmental renal branch and did not require surgery since it did not induced further impairment of renal function. Among the 10 remaining patients, nine PAT were classified as immediate angiographic success. One incomplete result required a second PTA 6 months later. Three important inguinal hematomas were observed and blood transfusion was required in 2. Seven patients have been reevaluated after a follow-up of 3 to 22 months. Restenosis occurred in two patients, 6 and 20 months respectively after PTA. A successful surgical revascularization was performed in these 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Localization of primary hyperaldosteronism].

After diagnosis of primary aldosteronism on the basis of biochemical evidence, the detection of the tumour is of crucial importance in the management of the disease. We reviewed the efficacy of CT-Scan, Iodo-Cholesterol Scintigraphy, digitalized phlebography, adrenal vein sampling for steroid measurements (AVS), and Nuclear Magnetic Resonance (NMR) in 160 hypertensive patients with primary aldosteronism. Diagnosis of Conn's adenoma (n = 96) or Adrenal Hyperplasia (n = 40) was confirmed by surgery or at least two concordant tumour localization tests. Scintigraphy gave a correct diagnosis in 53% of the 51 exams, CT-Scan in 82% of the 85 exams, and phlebography in 79% of 61 exams. Plasma Aldosterone/Cortisol ratio was 5 times higher on the side of adenoma in 55% of the 47 cases but this ratio was also present in 23% of 22 patients with adrenal hyperplasia. Each procedure exhibited few false positive and false negative cases. NMR performed in 15 patients with Conn's adenoma identified all the cases. But tumours displayed a signal close to the liver signal and identical to the normal adrenal. These results and the risk of invasive procedure (failure of catheterization of the right adrenal vein (n = 6) and adrenal haematoma (n = 2) lead us to propose a schema of exploration of patients with primary aldosteronism. The CT-Scan could be performed at the first step once the biological diagnosis confirmed. Phlebography and AVS will be performed only if tumour was less than 1 cm at the CT-Scan despite important biological abnormalities. This schema requires to be validated by a prospective evaluation.

Adenoma↗
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↗
PubMed1987

Validation of a digital videodensitometric program analysis for measurement of left ventricular ejection fraction.

Left ventricular (LV) function was studied in 30 patients using digital subtraction angiography by the intravenous approach. Each ventriculogram was processed with a specific videodensitometric analysis to determine LV ejection fraction. The program was verified in an experimental set-up consisting of nine latex balloons filled with contrast medium. Its validation has been established by comparing videodensitometric results with classical results supplied by geometric methods. A good correlation was obtained (r = 0.9449) and, furthermore, with experimental models, videodensitometric analysis seemed to be more accurate than geometric analysis. Digital videodensitometry appears to be a valuable and accurate method for quantifying LV function, and a promising technique for determination of the real volumes.

Adolescent↗