Biomedical subjects
Publications and source records attributed to C Privat.
Gastric diverticula are rare. The retroperitoneal site of subcardial diverticula may be suggestive of a left adrenal mass on CT and MR. The authors report two cases. Radiological demonstration of a communication with the stomach confirms the diagnosis.
PURPOSE: To compare the angulation at the origin of dysplastic renal arteries compared to atherosclerotic renal arteries, in order to improve the technique for percutaneous transluminal angioplasty of FMD. MATERIALS AND METHODS: Retrospective analysis of 40 aortograms in patients who underwent renal angioplasty for dysplastic stenosis, with comparison with 45 control aortograms (with or without atherosclerotic lesions of the renal arteries). The angle of implantation of the renal arteries was measured relative to the aortic axis in the frontal plane, taking into account only the angulation of its proximal segment. We identified three types of kidneys with regard to their position relative to the renal artery ostium. RESULTS: The angle of implantation of dysplastic renal arteries is significantly sharper compared with the control group (63.8 degrees vs 80.9 degrees, p = 0.0001), irrespective of the side. The angulation did not correlate with the position of the kidney or the direction of the renal artery, suggesting a congenital origin. CONCLUSION: The angle of implantation of the dysplastic renal arteries relative to the aortic axis in the frontal plane is sharper than the angle measured in non dysplastic renal arteries.
Vascular endothelial cells have been found to produce a relaxant mediator, identified as nitric oxide (NO) and implicated in numerous physiological functions. Subsequently, there has been an intensive search for accurate and specific detection methods to measure biological NO production. In the present study, we compared three approaches to evaluate NO production, based respectively on the Griess reaction (that quantifies nitrites and nitrates after their reduction), on the hemoglobin reaction (that quantifies oxyhemoglobin to methemoglobin transformation by NO), and on the electrochemical NO detection with a porphyrinic micro-probe. Comparison was made both under standard conditions and biological conditions, through calibration curves and measurements of histamine-induced NO production by cultured human endothelial cells and its modulation by L-arginine and N(omega)-monomethyl-L-arginine. We demonstrated that these three methods differ in terms of sensitivity and selectivity. The hemoglobin reaction and nitrate measurements suffer from a lack of specificity. Nitrite determination by the Griess reaction was hardly suitable for kinetic studies but it remains useful for the evaluation of basal NO production. The electrochemical technique, although it does not allow measurement of basal NO production, is the only one to exhibit great sensitivity and specificity and to allow instantaneous and non destructive measurements. This study brings up the potential hazards and pitfalls that may be associated with the various methods.
Immobilization secondary to spinal cord injury is associated with a marked and rapid atrophy of trabecular bone (disuse osteoporosis). This is due to an early increase of osteoclastic bone resorption associated with a pronounced decreased osteoblastic bone formation. Bisphosphonates are antiosteoclastic compounds and they have been effective in preventing disuse osteoporosis. However, some of them also depress osteoblastic activity and may impair the mineralization process. Tiludronate was shown effective in reducing bone resorption in several metabolic bone diseases without inducing mineralization defects. Twenty paraplegic patients (6 females and 14 males) were randomly assigned to three groups: 6 patients entered the placebo group; 7 patients received tiludronate 200 mg/day; and 7 received 400 mg/day. Histomorphometric analysis was performed on transiliac bone biopsies before and after 3 months treatment. An insignificant decrease of bone volume was observed in the placebo group and the 200 mg group. In patients receiving 400 mg/day, a slight increase was noted. Osteoid parameters changed nonsignificantly in three groups although the 400 mg group exhibited a slight tendency to decrease osteoid volume and thickness. Eroded surfaces increased in all groups. The number of osteoclasts (identified histochemically by TRAP staining) increased in the placebo group but decreased in groups receiving tiludronate. Tiludronate appears effective in reducing bone resorption without impairing bone formation in a manner that preserved bone mass and bone cell coupling.
PURPOSE: To investigate whether a correlation exists between aortic and renal arterial calcifications detected with spiral CT and significant angiographic renal artery stenosis (RAS). METHODS: Forty-two patients (mean age 67 years, range 37-84 years), of whom 24 were hypertensive, prospectively underwent abdominal helical CT and aortic and renal arteriography. The 3-mm thickness CT scans (pitch = 1) were reconstructed each millimeter. A manual outline of the renal artery including its ostial portion was produced. Calcific hyperdensities were defined as areas of density more than 130 HU. CT data were compared with the presence or absence of RAS on angiography (24 cases); hypertension and age were taken into account (Mann-Whitney U-test). RESULTS: CT detection and quantification appeared to be reliable and reproducible. We did not find any correlation between aortic and renal arterial calcifications and RAS, even for the patients above 65 years, with or without hypertension. There was no correlation either between calcifications and hypertension in patients without RAS. CONCLUSION: In this population, aortic and renal arterial calcifications have no predictive value for RAS.
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