Biomedical subjects
Publications and source records attributed to C Gautier.
This case report highlights the complementarity of noninvasive imaging modalities in the diagnosis of extracranial cerebral arteries lesions. The need for a strategy in the treatment of patients with combined lesions is discussed.
AIM: To assess the feasibility and to demonstrate the potential clinical application of intravascular doppler in the evaluation of renal blood flow in patients with hypertension and normal renal arteries. MATERIALS AND METHODS: Intravascular doppler was used to measure renal blood flow in 19 patients (34 kidneys) during arteriography to rule out renovascular hypertension. Arteriography showed no evidence of renal artery stenosis in any patient. Hemodynamic parameters, renal artery diameter, and doppler measurements were undertaken at baseline, after injection of a bolus (10 ml) of normal (0.9%) saline, and after injection of isosorbide dinitrate (1 mg diluted in 10 ml normal saline). RESULTS: Repeated measurements of renal blood flow confirmed the reproducibility of the technique. Basal blood flow was similar in both right and left kidneys; injection of vehicle solution (10 ml normal saline) had no effect on doppler parameters. Injection of isosorbide dinitrate resulted in a significant increase in renal blood flow velocity reflecting an increase in renal blood flow; this demonstrates the existence of a renal flow reserve. The degree of increase in renal blood flow varied significantly between kidneys. CONCLUSIONS: Intravascular doppler is a safe, effective, and reproducible technique for measurement of renal blood flow. It allows evaluation of variations in renal blood flow in response to diverse vasoactive drugs or other vasomotor stimuli. The present study demonstrated the heterogenous response of renal blood flow in response to vasodilator stimuli.
PURPOSE: Ultrasonographic follow up of patients with supra-aortic arteries angioplasty and stenting was performed to determine the normal characteristics and to detect restenosis or thrombosis at the repair site. MATERIAL AND METHODS: Twenty-eight patients were followed. The delay between the procedure and the ultrasonographic examination was 1 to 5 years. There were 32 procedures: 7 carotid angioplasties with stenting; 32 vertebral angioplasties (2 stentings), 2 brachiocephalic artery angioplasties (1 stenting); 1 subclavian artery angioplasty. The ultrasonographic examination included morphological and bilateral flow analysis. The usual criteria were measured. Special attention has been given to the morphological aspect of the stents. RESULTS: All of the carotid stents were patent. No restenosis appeared during the follow up. A parietal thickening was observed in one patient without significant reduction of the arterial lumen. There were one vertebral and one brachiocephalic stent thrombosis. The results of the ultrasonographic examinations correlated well with magnetic resonance imaging. CONCLUSION: The ultrasonographic follow up of supra aortic arteries angioplasty and stenting is feasible. An early examination is recommended after the vascular procedure to control the efficacy of the repair and to detect and quantify the residual lesions. This phase is compulsory for an optimal long term follow up.
Atheromatous ischaemic renal vascular disease (AIRVD) comprises ischaemic renal disease, atheromatous disease of the large arteries and intra-renal atheromatosis. Cholesterol emboli and lesions of nephroangiosclerosis are often associated, affecting the two kidneys. It is an increasingly common cause of chronic renal failure in an aging population, affecting 12 to 14% of new patients requiring dialysis in the United States. Atheromatous stenoses are very progressive with a risk of renal atrophy; they are a marker of polyvascular disease, often detected during other angiographic investigation. Hypertension secondary to the stenosis, still incorrectly called renovascular hypertension, is, however rare, affecting less than 0.5% of hypertensives. For economic reasons, it is important to select patients who need complementary investigation. In view of the absence of specific signs of the pathology, the "presumptive" diagnosis is based on a range of clinical and biological results, especially in a high risk context. The method of investigation varies from team to team, depending on the availability of equipment, the experience of the operators and the patient himself. Duplex Doppler, spiral angioscan and magnetic resonance angiography are the most pertinent investigations for the management of AIRVD. When the diagnosis of renal artery stenosis has been made, the problem of revascularisation, the objective of which is to preserve or restore the functional nephronic mass, has to be treated to prevent progression to end stage renal failure. Although epidemiological and physiopathological evidence is in favour of revascularisation, only renal salvage procedures are imperative. Apart from these indications, the clinical benefits of revascularisation have not yet been demonstrated. In all cases, the control of associated risk factors is essential to maintain the success of revascularisation and slow down the progression of atheromatous disease.
BACKGROUND: The serotonin-1A (5HT1A) receptor system has been implicated in the pathophysiology of major depression by postmortem studies of suicide victims and depressed subjects dying of natural causes. This literature is in disagreement, however, regarding the brain regions where 5HT1A receptor binding differs between depressives and controls and the direction of such differences relative to the normal baseline, possibly reflecting the diagnostic heterogeneity inherent within suicide samples. PET imaging using the 5HT1A receptor radioligand, [11C]WAY-100635, may clarify the clinical conditions under which 5HT1A receptor binding potential (BP) is abnormal in depression. METHODS: Regional 5HT1A receptor BP values were compared between 12 unmedicated depressives with primary, recurrent, familial mood disorders and 8 healthy controls using PET and [carbonyl-11C]WAY-100635. Regions-of-interest (ROI) assessed were the mesiotemporal cortex (hippocampus-amygdala) and midbrain raphe, where previous postmortem studies suggested 5HT1A receptor binding is abnormal in depression. RESULTS: The mean 5HT1A receptor BP was reduced 41.5% in the raphe (p < .02) and 26.8% in the mesiotemporal cortex (p < .025) in the depressives relative to the controls. Post hoc comparisons showed the abnormal reduction in 5HT1A receptor BP was not limited to these regions, but extended to control ROI in the occipital cortex and postcentral gyrus as well. The magnitude of these abnormalities was most prominent in bipolar depressives (n = 4) and unipolar depressives with bipolar relatives (n = 4). CONCLUSIONS: Serotonin-1A receptor BP is abnormally decreased in the depressed phase of familial mood disorders in multiple brain regions. Of the regions tested, the magnitude of this reduction was most prominent in the midbrain raphe. Converging evidence from postmortem studies of mood disorders suggests these reductions of 5HT1A receptor BP may be associated with histopathological changes involving the raphe.
Explore the source record for details and available documents.
OBJECTIVE: We evaluated the role of helical CT angiography rendering techniques in the assessment of renal artery fibromuscular dysplasia. MATERIALS AND METHODS: Twenty hypertensive patients (mean age, 56 years) with angiographically proven renal artery fibromuscular dysplasia were studied by CT angiography. The acquisition protocol was collimation, 3 mm; table speed, 3 mm/sec; and incremental algorithm, one. Maximum-intensity-projection and shaded-surface-display reconstructions and transverse sections were reviewed by a consensus panel to determine the sensitivity and specificity of each technique in revealing renal artery fibromuscular dysplasia. RESULTS: Helical CT angiography enabled successful diagnosis of fibromuscular dysplasia in all 20 patients. Helical CT angiography showed 31 of 34 pathologic arteries and 33 of 38 lesions. Aneurysms (>6 mm) on arteriography (n = 12) were revealed in 83% of transverse sections, 75% of maximum-intensity-projection reconstructions, and 58% of shaded-surface-display reconstructions. Lesions that had a string of pearls appearance on arteriography (n = 19) were shown in 53% of transverse sections, 84% of maximum-intensity-projection reconstructions (p < .05 compared with transverse sections), and 74% of shaded-surface-display reconstructions. Stenoses (n = 7 on arteriography) were revealed in 57% of transverse sections, 71% of maximum-intensity-projection reconstructions, and 57% of shaded-surface-display reconstructions. Maximum intensity projection alone revealed 30 (79%) of the 38 angiographic lesions; however, using both maximum intensity projections and transverse sections increased the sensitivity to 87%. CONCLUSION: Helical CT angiography, especially the combination of transverse sections and maximum-intensity-projection reconstructions, can reliably reveal renal artery fibromuscular dysplasia. However, because some lesions may not be shown, arteriography with pressure measurements remains the only technique that can assess the physiologic significance of the dysplasia.
The aim of the study was to evaluate the anatomic results of percutaneous transluminal renal angioplasty in a population of 113 hypertensive patients (66 men, mean age 63 years) who had a significant renal artery stenosis (atheromatous in 105 patients and fibrodysplastic in the eight others). Conventional angioplasty was performed in 89 arteries, and stent implantation in 46 cases. Stenting was associated with a better immediate result than simple angioplasty for atheromatous stenoses (rate of residual stenosis < 30% = 93.5% and 71.2% respectively, p < 0.003). Technical success for angioplasty of atheromatous stenoses was achieved in 73.8% of procedures involving non ostial lesions and 51.6% for ostial stenoses (p = 0.05). Restenosis was detected 6.3 +/- 0.3 months later (by echodoppler and/or helical computed tomography angiography) in 9.1% of cases after stent implantation and in 47% after simple angioplasty (p = 0.00017). The presence of a residual stenosis < 30% immediately after revascularization was associated with a significantly (26.4% versus 50%, p = 0.044) lower rate of restenosis. In conclusion, this study confirms the utility of percutaneous transluminal renal angioplasty for treatment of renovascular hypertension, particularly with the utilisation of stents for atheromatous and ostial stenoses.
The aim of this study was to determine the sensitivity and specificity of two non invasive methods for the diagnosis of renal artery stenosis, compared with renal angiography. Retrospective analysis of 113 hypertensive patients who underwent renal angiography permitted us to evaluate the results of echo-Doppler (n = 53) and helical computed tomography angiography (n = 50). Regarding echo-Doppler, sensitivity and specificity were 0.75 and 0.86 respectively (40 true positives/53 stenoses, and negative result in 38/44 normal arteries). Regarding helical CT angiography, these values were 0.94 and 0.95 respectively (positive result in 45/48 stenoses, and 41 true negatives/43 normal arteries). These results suggest that echo-Doppler and helical CT angiography are two reliable methods for the diagnosis of renal artery stenosis. Thus, renal angiography could be reserved for patients who may require percutaneous transluminal renal angioplasty.
Explore the source record for details and available documents.
Based on an extensive sampling regime from both nesting populations and bycatch, frequency analyses of mitochondrial (mt) DNA control region haplotypes in the Mediterranean were used to assess the genetic structure and stock composition of the loggerhead sea turtle, Caretta caretta, in different marine fisheries. The analyses show the following. (i) In drifting longline fisheries working in Mediterranean pelagic habitats 53-55% of turtles caught originated from the Mediterranean stock; (ii) In bottom-trawl fisheries all turtle bycatch is derived from this regional stock; (iii) This regional stock contribution to fishery bycatch suggests that the population size of the Mediterranean loggerhead nesting population is significantly larger than previously thought. This is consistent with a recent holistic estimate based on the discovery of a large rookery in Libya. (iv) Present impact of fishery-related mortality on the Mediterranean nesting population is probably incompatible with its long-term conservation. Sea turtle conservation regulations are urgently needed for the Mediterranean fisheries. (v) The significant divergence of mtDNA haplotype frequencies of the Turkish loggerhead colonies define this nesting population as a particularly important management unit. Large immature and adult stages from this management unit seem to be harvested predominantly by Egyptian fisheries. (vi) Combined with other data, our findings suggest that all the nesting populations in the Mediterranean should be considered as management units sharing immature pelagic habitats throughout the Mediterranean (and possibly the eastern Atlantic), with distinct and more localized benthic feeding habitats in the eastern basin used by large immatures and adults. (vii) Between the strict oceanic pelagic and the benthic stages, immature turtles appear to live through an intermediate neritic stage, in which they switch between pelagic and benthic foods.
Relative-rate tests may be used to compare substitution rates between more than two sequences, which yields two main questions: What influence does the number of sequences have on relative-rate tests and what is the influence of the sampling strategy as characterized by the phylogenetic relationships between sequences? Using both simulations and analysis of real data from murids (APRT and LCAT nuclear genes), we show that comparing large numbers of species significantly improves the power of the test. This effect is stronger if species are more distantly related. On the other hand, it appears to be less rewarding to increase outgroup sampling than to use the single nearest outgroup sequence. Rates may be compared between paraphyletic ingroups and using paraphyletic outgroups, but unbalanced taxonomic sampling can bias the test. We present a simple phylogenetic weighting scheme which takes taxonomic sampling into account and significantly improves the relative-rate test in cases of unbalanced sampling. The answers are thus: (1) large taxonomic sampling of compared groups improves relative-rate tests, (2) sampling many outgroups does not bring significant improvement, (3) the only constraint on sampling strategy is that the outgroup be valid, and (4) results are more accurate when phylogenetic relationships between the investigated sequences are taken into account. Given current limitations of the maximum-likelihood and nonparametric approaches, the relative-rate test generalized to any number of species with phylogenetic weighting appears to be the most general test available to compare rates between lineages.
The phylogenetic relationships between species of yeasts assigned to the Saccharomyces sensu stricto group, which includes Saccharomyces cerevisiae and Saccharomyces bayanus, were studied together with Saccharomyces pastorianus and Saccharomyces paradoxus. The experimental approaches used were RFLP analysis of the PCR-amplified rDNA internal transcribed spacer (ITS) and intergenic spacer, and total ITS sequence analysis. Both RFLP and sequence analyses gave fairly similar results. The gene trees generated with either of the two data sets showed the distribution of the yeasts into two major, well-separated, phylogenetic clusters called 'cerevisiae' and 'bayanus'. The 'cerevisiae' cluster included the S. cerevisiae type strain, together with most of the species (16 out of 23), whereas the 'bayanus' cluster included the remaining seven type strains. Therefore, analysis of rDNA sequences confirmed S. cerevisiae and S. bayanus as two well-defined taxa. However, S. pastorianus and S. paradoxus, the two other usually accepted taxa of the now-defined Saccharomyces sensu stricto complex, could not be clearly separated from S. bayanus and S. cerevisiae, respectively. However, in both PCR-RFLP and ITS sequence analyses, S. paradoxus had the outermost position in the 'cerevisiae' cluster. PCR-RFLP analysis of the ribosomal spacer sequences was also carried out on 26 Saccharomyces strains isolated in various wine-growing regions of France in an attempt to clarify their positions in the Saccharomyces phylogenetic tree. Compared to the diversity of the Saccharomyces type strains, less genetic diversity was detected among these yeasts and several of them exhibited identical RFLP patterns. Most of the wine yeast strains (16 out of 26) were closely related to each other and were found within the 'cerevisiae' cluster. The remaining 10 wine yeast strains branched within the 'bayanus' cluster. PCR-RFLP analysis of ribosomal spacer sequences thus appears to be a useful and appropriate method for the correct characterization of Saccharomyces yeast strains used in food processing.
Intravascular Doppler is widely used for experimental studies in the coronary circulation. We designed this study to assess baseline bloodflow and arteriolar resistance in the porcine renal circulation and to study the vasomotor responses of vasoactive drugs. In anesthesized piglets (n = 15), renal arterial diameter was measured with quantitative angiography and blood flow velocity with a Doppler wire (Cardiometrics). Bloodflow and resistances were calculated at baseline and after injection of vasoactive drugs (isosorbide dinitrate, papaverine). This allowed us to determine the renal bloodflow reserve (the capacity of the kidney to augment basal bloodflow). Injection of isosorbide dinitrate was associated with an increase in average peak velocity of 64% (P < 0.01) and a small (from 4.5 to 4.74, P < 0.01) but significant increase in renal artery diameter, resulting in an increase in bloodflow of 82% (P < 0.01) and a decrease in arteriolar resistance of 46% (P < 0.01). Bloodflow returned to baseline (4.76 +/- 1.48 mL/s) approximately 5 min after isosorbide injection. Average Peak Velocity increased almost twofold after papaverine injection (60 +/- 10 to 108 +/- 24 cm/sec, P < 0.01). There was a significant (P < 0.01) increase in arterial bloodflow of 96% in the right and 79% in the left renal artery after injection of papaverine with a corresponding significant (P < 0.01) decrease in arteriolar resistance of 49% in the right and 44% in the left renal artery. Using a combination of quantitative angiography and intravascular Doppler allows easy measurement of baseline renal blood flow and of the effects of vasodilator drugs on bloodflow and resistance. The results show that a vasodilatator reserve exists in the renal circulation but is less marked than that reported in the coronary circulation.
BACKGROUND AND PURPOSE: It has been shown previously that cerebral microemboli may occur frequently in patients with a normal mechanical heart valve (MHV) without prior history of stroke. Some arguments strongly suggest that these microemboli have a gaseous origin. In other circumstances such as extracorporeal circulation or decompression in divers, it has been demonstrated that cerebral microbubbles could lead to some deterioration in cognitive functions. Therefore, we have studied attention and memory, which are among the most impaired cognitive functions as demonstrated in previous studies, in patients with an MHV. METHODS: Three groups of 12 volunteers each were composed of patients with an MHV and embolic signals in the cerebral circulation (group 1), patients with biological prostheses (group 2), and healthy subjects (group 3). Groups were carefully matched for age and verbal intellectual abilities. For each group, a transcranial Doppler examination was performed and a set of cognitive tests assessing sustained and selective attention and episodic and working memory was administered. RESULTS: The mean embolic rate was 29 per hour in patients with an MHV. No embolus was detected in the other 2 groups. Episodic memory was significantly modified in both groups 1 and 2 compared with the control group for tasks that required high-processing resources. Working memory performance was significantly decreased in MHV patients. No between-groups differences were observed for the other parameters. CONCLUSIONS: Alteration of episodic memory can be attributed to a long-term effect of the surgical procedure. Deterioration of working memory can be related to the presence of cerebral microemboli in MHV patients.
Insulin like growth factor I (IGF-I) is believed to be a potent para/autocrine stimulator of Leydig cell function in adult testis. We investigated whether IGF-I is also an intratesticular regulator of fetal Leydig cell function by measuring its production in the fetal testis and its ability to affect testicular steroidogenesis during fetal development. Northern blot analysis revealed one major IGF-I transcript of 7-7.5 kb and two minor transcripts of 3.8 and 1.8 kb in 20.5 day fetal testis. IGF-I was detected by RIA in 16.5 fetal day testes, and the amounts of IGF-I secreted by 16.5 and 20.5 fetal day testes in vitro were much greater than the amounts contained in the testes, indicating active synthesis in culture. The secretion of IGF-I by the fetal testis in vitro was increased with testicular age and time in culture. It was not modified by gonadotropins or (Bu)2cAMP. Testosterone secretion by fetal testes explanted 13.5, 16.5, 18.5, and 20.5 days after conception and cultured in the presence or absence of 100 ng/ml LH for 3 days was not affected by the addition of 50 ng/ml IGF-I to the medium. In contrast, the addition of IGF-I to dispersed fetal testicular cells cultured for 3 days in the presence or absence of LH increased the number of Leydig cells identified by a positive cytochemical reaction for 3beta-hydroxysteroid dehydrogenase (3betaHSD). This was more pronounced with cells from 16.5- day-old fetuses (stage when the fetal Leydig cells are differentiating in vivo) than with 20.5-day-old fetuses cells (stage when the number and the function of fetal Leydig cells are stable or decreasing). It results from both an increased differentiation of mesenchymal cells in fetal Leydig cells and an increase in the mitotic index of the fetal Leydig cells, as inferred from the small increase in the percentage of bromodeoxyuridine/3betaHSD-positive cells. Both LH and IGF-I increased significantly testosterone production by day 16.5 cells. In the presence of LH, a high amount of testosterone was produced per 3betaHSD-positive cell; IGF-I further increased this production. This effect was not observed with day 20.5 cells. The amounts of testosterone produced per 3betaHSD-positive cell cultured in the presence of both LH and IGF-I were more than additive. Like IGF-I, insulin (50 ng/ml) increased testosterone secretion per 3betaHSD-positive cells in cultures of day 16.5 cells, but not in those of day 20.5, cells. Lastly, IGF-I also increased the steroidogenic activity of each Leydig cell in cultures containing (Bu)2cAMP, but its effects were weaker than those observed in the presence of LH. This suggests that IGF-I has sites of action both upstream and downstream cAMP generation. These results suggest that IGF-I acts as paracrine/autocrine factor in the differentiation and activity of fetal Leydig cells.
UNLABELLED: We report a case of severe infantile cystic acne, which required a treatment with oral isotretinoin. CASE REPORT: The patient, a 22-month-old boy, presented cystic acne since 6 months of age. The child was otherwise healthy and endocrine evaluation was normal. Previous treatments had no effect, oral isotretinoine led to cure without secondary effects. COMMENTS: The etiology of infantile acne is not clearly defined, but may result from a persisting androgen-driven stimulation of sebaceous glands. Oral isotretinoin is safe and effective in case of recalcitrant infantile acne, but close monitoring is necessary because of the well-known side effects of oral retinoids.
BACKGROUND: Rouget du porc, or swine erysipelas, usually occurs in man as Rosenbach's erysipeloid. Septicemic forms are more uncommon and can be associated with dermal involvement far from the site of inoculation. We report a case in a patient given corticosteroid therapy for systematic lupus. CASE REPORT: A 50-year-old farmer was seen with fever, infiltrative erythema of the long finger and dorsal lesions on the ring finger which developed after a skin lesions caused by a duck. The diagnosis of septicemic rouget du porc was made after isolating the germ from blood cultures. There was no associated endocarditis. Fever and skin lesions totally regressed after treatment with ceftriaxone. DISCUSSION: The diagnosis of erysipeloid was supported by epidemiologic arguments and characteristic clinical features. The corticosteroid therapy was probably a favoring factor for development of septicemia. Positive diagnosis is usually obtained from blood culture but the germ can be isolated from skin biopsies at the site of inoculation. Our patient was free of endocarditis which should always be suspected. Endocarditis is frequent and often fatal. Intravenous high-dose penicillin G is recommanded treatment.