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Biomedical subjects

B Giraudeau

Publications and source records attributed to B Giraudeau.

At least 19 recordsLinked to original sources

Accuracy of color-Doppler in the quantification of proximal vertebral artery stenoses.

BACKGROUND: Vertebrobasilar (VB) strokes appear to have the same causes as carotid strokes. Obstructive lesions of proximal vertebral arteries probably occur in about 30% of stroke patients. PURPOSE: Our aim was to assess the validity of color Doppler sonography compared to selective intra-arterial angiography in the quantification of proximal vertebral artery stenoses. MATERIALS AND METHODS: A prospective blind study of 316 vertebral arteries was undertaken between 1996 and 1998. One hundred and fifty-eight patients with cerebrovascular disorders without cerebral hemorrhage were studied consecutively by frequency or amplitude color Doppler flow imaging and intra-arterial angiography. The lesions were quantified by morphological and hemodynamic criteria and classified into 6 groups: 0% 207 arteries; 1-29% 32 arteries; 30-49% 29 arteries; 50-69% 13 arteries; 70-99% 23 arteries; 100% 12 arteries. RESULTS: Ten of the 12 occlusions were identified, the 2 false-negatives were due to 2 revascularized vessels. Moderate stenoses (<50%) were differentiated from tight stenoses (>50%) using hemodynamic criteria. The majority of false-negative stenoses (38) in the different groups were related to intrathoracic or very deep origin of the artery, anechogenic stenosis or a tortuous vessel. Stenoses greater than 70% were diagnosed in 71% of cases with a specificity of 99%. The kappa value was 0.80. CONCLUSION: Duplex sonography should be proposed first in VB attacks or stroke to detect and quantify vertebral artery stenoses for surgery and angioplasty.

Arterial Occlusive Diseases↗

Despite financial penalties, French physicians' knowledge of regulatory practice guidelines is poor.

OBJECTIVE: To evaluate the level of awareness and knowledge of regulatory practice guidelines (references medicales opposables [RMOs] or regulatory medical references) implemented to control ambulatory care costs among French family physicians. DESIGN: Observational study. Participants were asked to identify RMO topics among a list of actual and fictitious RMO topics and the RMOs themselves among a list of actual and fictitious RMOs. SETTING: General practice in France. SUBJECTS: Three hundred twenty-one family physicians. MAIN OUTCOME MEASURE: Average score of 100 (95% confidence interval [CI]) on the awareness of RMO topics and knowledge of the RMOs. RESULTS: The average overall score was 55.8 of 100 (95% CI, 53.3-58.3) for the awareness of the RMO topics and 50.5 (95% CI, 48.3-52.7) for knowledge of the RMOs themselves-53.2 (95% CI, 51.1-55.3) for diagnostic RMOs and 47.8 (95% CI, 45.6-50.0) for therapeutic RMOs. Chance would have yielded an expected mean score of 50. A statistically significant difference was noted between the average score for actual (62.2) and fictitious (43.2) RMOs, P<.001. None of the respondents correctly identified all 24 correct answers. CONCLUSION: Despite implementation of RMO policy, the awareness and knowledge of RMOs among French family physicians seem weak. The number of RMOs and the difficulties in controlling physicians probably explain these results. Thus, it is doubtful that the RMO policy will have a long-term effect on physicians' behavior.

Clinical Competence↗

Initial color Doppler findings in retinal vein occlusion.

PURPOSE: We assessed early hemodynamic characteristics of various types of retinal vein occlusion using color Doppler imaging and spectral analysis. METHODS: We measured the maximum systolic and diastolic blood flow velocities and the resistance index (RI) in the central retinal artery and the maximum and minimum blood flow velocities in the central retinal vein of affected eyes and contralateral unaffected eyes in 102 adults (63 men and 39 women; mean age, 61 +/- 14.6 years) who presented with retinal vein occlusion. Sixty-three control subjects (27 men and 36 women; mean age, 50 +/- 22.1 years) were also investigated. RESULTS: No significant differences in hemodynamic characteristics were found between the control subjects' eyes and the patients' unaffected eyes. In the 18 cases of ischemic central retinal vein occlusion, the mean diastolic arterial flow velocity (p = 0.005) and venous flow velocity (p < 0.04) were lower and the mean RI was higher (p = 0. 0002) in the affected eyes than in the unaffected contralateral eyes. In the 51 cases of nonischemic central retinal vein occlusion, the mean diastolic arterial flow velocity (p < 0.0001) and venous flow velocity (p < 0.0001) also were lower and the mean RI (p < 0.0001) was higher in the affected eyes than in the unaffected contralateral eyes. These variables were different in the ischemic versus nonischemic types of central retinal vein occlusion. In the 33 cases of branch retinal vein occlusion, no significant differences were observed in arterial or venous blood flow velocities in the affected versus unaffected eyes. The mean RI in the affected eyes was significantly higher (p = 0.009) in patients with central versus branch retinal vein occlusion. CONCLUSIONS: These results suggest that previous arterial disorders were not involved in the pathogenesis of central retinal vein occlusion in these patients. The findings also support the value of Doppler imaging and spectral analysis in the diagnosis and evaluation of retinal vein occlusion and confirm the involvement of arterial flow in venous occlusion.

Adult↗

Effects of spinal cord X-irradiation on the recovery of paraplegic rats.

Axonal regrowth is limited in the adult CNS, especially in the spinal cord, one of the major sites of traumatic lesions. Pathophysiological changes occurring after spinal cord injury include complex acute, subacute, and late processes. In this study, we assessed whether X-irradiation interferes with the acute/subacute phases, thereby improving the functional recovery of paraplegic animals. Two days after acute compression of adult rat spinal cords, various doses (0, 2, 5, 10, 20 Gy) of X-rays were administered as one single dose to the compression site. The animals were functionally evaluated over the course of 1 month after injury, using the Tarlov scale and the Rivlin and Tator scale. We also designed a "physiological" scale, including an assessment of urinary function and infection, appropriate for the evaluation of spinal-cord-lesioned animals. Behavioral analysis suggested that the high doses, 20 Gy and, to a lesser extent, 5 and 10 Gy, were toxic, as shown by morbidity rate and "physiological" score. The 2-Gy group showed better motor performances than the lesioned nonirradiated (LNI) animals and the 5- and 20-Gy groups. Motor performance in the 5-, 10-, and 20-Gy groups was poorer than that seen in the LNI group. Gliosis was reduced in the 2-Gy group compared to LNI animals, and there was high levels of gliosis in the highly (>/=5 Gy) irradiated animals. There was a 23% less lesion-induced syringomyelia in the 2-Gy group than in the other groups (LNI and 5-20 Gy). Thus, low doses of X-rays may interfere with the formation of syringomyelia and glial scar, thereby facilitating the recovery of paraplegic animals. These findings suggest that low-dose irradiation of the lesion site, in association with other therapies, is a potentially promising treatment for improving recovery after spinal cord injury.

Acute Disease↗

Evaluation of left ventricular systolic function by 3D echocardiography: a comparative study with X-ray angiography and radionuclide angiography.

OBJECTIVE: the aim of this study was to evaluate left ventricular systolic function by 3D ultrasound as compared to with radionuclide and X-ray angiographies. METHODS: one hundred and four patients were examinated by 3D ultrasound (3D-US) but only 72 examinations were successful. Thirty patients were investigated by 3D-US, M-mode US or bidimensional (2D) US, and X-ray angiography (group I) and 42 patients were investigated by 3D-US, M-mode, or 2D, and radionuclide angiography (group II). RESULTS: the correlation between ejection fraction (EF) evaluated by 3D-US and reference methods was found to be good and similar for the two groups (r=0.75; P<10(-4) for group I and r=0.76; P<10(-4) for group II). The correlation between EF calculated by conventional 2D-US and by reference methods was lower (r=0.60; P=0.04 for group I and r=0.54; P=0.001 for group II). The correlation between EF evaluated by 3D- and 2D-US was modest (r=0. 55; P=0.001 for the whole group). The correlation between 3D-US left ventricle end-diastolic volume (EDV) and end-systolic volume (ESV) and those evaluated by X-ray angiography was also modest (r=0.33; NS for EDV and r=0.60; P<10(-4) for ESV). The correlations between EDV and ESV in 3D-US, and those evaluated from radionuclide angiography were fairly good and in the same range (r=0.76; P<10(-4) and r=0.87; P<10(-4)). CONCLUSION: the 3D-US system using a rotating probe in an apical view is valuable for evaluation of left ventricular systolic function.

Angiocardiography↗

Effects of current smoking and smoking discontinuation on renal function and proteinuria in the general population.

BACKGROUND: Smoking may adversely affect the progression of renal diseases. However, it is unknown whether smoking affects renal function in subjects without nephropathy. METHODS: In 1998, 28,409 volunteers from the general population were examined at the Institut Régional pour la Santé (IRSA). Renal function was estimated with creatinine clearance using the Cockcroft formula. Dipstick proteinuria was assessed on an overnight urine sample by a trained technician. RESULTS: Adjusted creatinine clearance was higher in current smokers than in former smokers and never smokers (100.6 +/- 13.6 vs. 98.8 +/- 13.9 mL/min/1.73 m2, P < 0.0001, and vs. 98.5 +/- 14.0 mL/min/1. 73 m2, P < 0.0001, respectively). This difference was predominant in men and weak in women, and was associated with the number of cigarettes smoked daily. The slope of the projected age-related decline in the creatinine clearance accelerated with age, but it was similar in current smokers, former smokers, and never smokers. Creatinine clearance was associated with a relative risk of proteinuria [for each mL/min/1.73 m2, the relative risk was 1.007 (95% CI, 1.000 to 1.015), P = 0.056, for 1+ or higher proteinuria; and 1.018 (1.004 to 1.030), P = 0.0078, for 2+ or higher proteinuria]. Current and former smokers had a marked risk of 2 or higher proteinuria [adjusted RR (95% CI), 3.26 (1.66 to 6.80), P = 0. 0009, and 2.69 (1.24 to 5.99), respectively, P = 0.013, vs. never smoking], which was independent of the daily or cumulative cigarette consumption. CONCLUSIONS: In the general population, smokers do not exhibit lower creatinine clearance than never smokers. In fact, creatinine clearance is slightly higher in current smokers at least in men, even when normotensive and hypertensive subjects are analyzed separately, but the difference is small, especially in women. This effect seems reversible upon smoking discontinuation. Chronic smoking results in a marked risk of irreversible proteinuria that may occur despite moderate smoking.

Adult↗

Radiographic assessment of hip osteoarthritis progression: impact of reading procedures for longitudinal studies.

OBJECTIVE: To compare radiographic reading procedures and evaluate their impact on sample size in hip osteoarthritis (OA) longitudinal studies. METHODS: Pelvic radiographs performed twice, three years apart, in 104 patients with hip OA were read by a single reader using the Kellgren and Lawrence system, joint space narrowing scale, and joint space width (JSW). Reading procedures were (a) films read as single radiographs, (b) films grouped by patient but read in random order, (c) films grouped by patient and chronologically ordered, all with landmarks for JSW measurements, (d) films read as single radiographs, without landmarks for JSW measurements. JSW was measured at the narrowest point with a 0.1 mm graduated magnifying glass. RESULTS: More Kellgren and Lawrence or joint space narrowing grades were modified respectively with the single (42% and 37%) than with the paired (32% and 23%) or chronologically ordered (34% and 29%) reading procedures. Variability of JSW progression was principally related to mean progression (88.3%) and landmarks (almost 10%). Standardised response means were -0.71 with the paired reading procedure with landmarks, -0.68 with the single reading procedure with landmarks, -0.65 with the single reading procedure without landmarks. With landmarks, 10% more patients would be needed using single than paired reading. Using single reading, 10% more patients would be needed without landmarks than with landmarks. CONCLUSION: Kellgren and Lawrence grading seems to be influenced by the reading procedure, as is joint space narrowing grading, for assessing hip OA. Paired reading procedure with landmarks for JSW should be recommended in longitudinal studies.

Disease Progression↗

[Is smoking history a risk factor of arterial hypertension in men?].

Former smokers exhibit decreased cardiovascular risk as compared to smokers who continue to smoke. However, smoking discontinuation results in weight gain which may be important and influence arterial pressure. From January 1st to June 30th, 1998, 12,417 volunteers (aged 20 to 69) were examined at the "Institut régional pour la santé" (IRSA, Regional Institute for Health), a group of 9 social medical centres in Western and Central France. The subjects were screened for a routine medical and biological check-up provided by their medical insurance. All of the subjects were interviewed by a trained nurse who completed a standardised questionnaire regarding personal medical history, current treatments and lifestyle behaviours (especially alcohol and smoking habits). A physician recorded clinical parameters including age, weight, height, systolic and diastolic arterial pressure. Body mass index (BMI) was calculated. Non smokers and former smokers represented 40.0% and 23.8% of the population respectively. The prevalence of a BMI 27.0 kg/m2 or greater was higher in former smokers than non smokers and current smokers. Systolic and diastolic arterial pressure in former smokers exceeded those of current smokers and non smokers by 4.2/1.1 mmHg and 2.8/1.6 mmHg respectively. Using logistic regression analysis, the relative risk of hypertension in former smokers was 1.24 (CI 95%: 1.10-1.39, p < 0.001) and 1.13 (0.995-1.29, p = 0.055) as compared to non smokers and current smokers, after adjustment for age and alcohol intake. Differences became non significant when BMI was entered in the model. The results of the present study suggest that former smoking status is associated with a higher prevalence of overweight which may cause a higher prevalence of hypertension.

Adult↗

[Evaluation of clinical decision rules].

The final goal of decision making rules is to help the clinician make a medical decision and limit heterogeneous practices. Three steps are needed to develop decision making rules for use in daily practice: 1) construction, 2) prospective validation, 3) study of its impact in terms of clinical practice and economics. The aim of this work was to review the details of these different steps basing the research on the Ottawa rules aimed at defining indications for radiography in patients presenting at the emergency room for ankle trauma.

Adolescent↗

[Strategy for early diagnosis of lung involvement in systemic scleroderma].

Systemic sclerosis (SSc) is an autoimmune disorder characterized by accumulation of collagen in affected organs, mainly the skin and the lungs, associated with abnormalities of the arterioles and capillaries. There are two types of pulmonary involvement, which influence long term prognosis: infiltration of the lungs and/or pulmonary artery hypertension. Full investigations into possible lung involvement must be performed systematically when SSc is diagnosed and during follow-up. The double pathophysiology sometimes makes diagnosis difficult but it must be made as early as possible in order to decide on the optimal treatment. The aim of this study was to evaluate the usual explorations and to propose biological markers to identify patients requiring more detailed lung investigations, in order to establish a diagnostic approach to treatment and follow-up patients with SSc.

Aftercare↗

[Are mortality indicators acceptable indicators for the quality of health care?].

IMPORTANCE OF PUBLISHING MORTALITY RATES: Mortality rates for certain interventions or disease states have been used over the last decade as indicators of the quality of care provided by a given hospital, unit or, medical team. If published, these rates would be a useful tool for decision makers in the process of fund allocations, for public information, and for promoting improved care in hospitals or units with a low classification. METHODOLOGICAL LIMITATIONS: It is difficult to adjust an indicator of mortality to disease-related risk factors and any modification of this adjustment can have major consequences on the validity of subsequent comparisons. The differences in mortality observed between hospitals and physicians can reflect not only differences in quality of care but also differences in approaches to disease-related risk factors, therapeutic choices, or coding practices. The lack of statistical power is a major limiting factor in interpreting differences in mortality rates. To evidence a statistically significant difference in mortality between two hospitals whose rates are respectively 0.5% and 1% (for example in total hip replacement patients), it would be necessary to include 4673 patients, a number which would correspond to 20 years data for a hospital performing 230 interventions per year. Consequently, the number of interventions performed in the most active hospitals would not be sufficient to make such comparisons. LIMITATIONS AND COUNTER EFFECTS: Some studies have demonstrated that the publication of mortality rates does not have a major influence on patients' decisions nor on physicians' choice of a referral hospital. It would have no effect on improving health care quality of the institutions cited. One the contrary, certain counter effects have been observed: modification in patient recruitment, higher-risk patients being referred to hospitals with unpublished mortality rates. For many authors, procedure indicators are more pertinent than outcome indicators for detecting differences in health care quality between different care structures.

France↗

Effects of joint lavage and steroid injection in patients with osteoarthritis of the knee: results of a multicenter, randomized, controlled trial.

OBJECTIVE: To evaluate the efficacy of joint lavage and intraarticular steroid injection, alone and in combination, in the treatment of patients with symptomatic knee osteoarthritis (OA). METHODS: Ninety-eight patients with painful tibiofemoral OA were enrolled in a prospective, randomized, controlled, 2 x 2 factorial-design trial of 6 months' duration. The 4 treatment groups consisted of 1) intraarticular placebo (1.5 ml of 0.9% normal saline), 2) intraarticular corticosteroids (3.75 mg of cortivazol in 1.5 ml), 3) joint lavage and intraarticular placebo, and 4) joint lavage and intraarticular corticosteroid. Outcome measures evaluated at baseline, week 1, week 4, week 12, and week 24 included severity of pain (100-mm visual analog scale [VAS]), global status (100-mm VAS), and Lequesne's functional index. RESULTS: No interaction between steroid injection and joint lavage was demonstrated. Patients who had undergone joint lavage had significantly improved pain VAS scores at week 24 (P = 0.020). In contrast, corticosteroid injection had no long-term effect (P = 0.313); corticosteroid injection was associated with a decrease in pain only at week 1 (P = 0.003) and week 4 (P = 0.020). After week 4, Lequesne's functional index was not significantly improved regardless of the assigned treatment. CONCLUSION: Compared with placebo, both treatments significantly relieved pain but did not improve functional impairment. The effects of the 2 treatments were additive. Cortivazol provided short-term relief of pain (up to week 4). The effects of joint lavage persisted up to week 24.

Aged↗

Assessing smallest detectable change over time in continuous structural outcome measures: application to radiological change in knee osteoarthritis.

Interpreting changes in continuous structural outcome measures is a common problem in clinical research and in daily practice. We propose a method for estimating whether difference observed between two successive measures in an individual constitutes a statistically relevant change or a change induced by variability. This statistically relevant change is based on an analysis of reproducibility. The continuous structural outcome measure investigated as an example was joint space width (JSW) measurement on standard X-rays, which is known to be the primary end-point for assessing structural osteoarthritis progression. The results of the present study demonstrate that cutoffs are closely dependent on all sources of variabilities in JSW measurement such as joint positioning, radiographic procedure, and the measurement process itself. Therefore, we suggest to determine cutoffs for each study using a representative sample of the population studied and using the procedures and methods of measurement of the specific study. This approach may easily be extended to other continuous structural outcome measures.

Aged↗

Blood lipid concentrations of docosahexaenoic and arachidonic acids at birth determine their relative postnatal changes in term infants fed breast milk or formula.

BACKGROUND: Factors other than dietary fatty acids could be involved in the variability observed in blood docosahexaenoate (22:6n-3) and arachidonate (20:4n-6) status in formula-fed infants. OBJECTIVE: We considered the 22:6n-3 and 20:4n-6 status at birth to be one of these factors and studied its influence on postnatal changes in term infants fed 4 different diets. DESIGN: The blood phospholipid composition was determined at birth and on day 42 of feeding in 83 term infants fed breast milk, nonsupplemented formula, or 2 different 22:6n-3-supplemented formulas. Relations between 22:6n-3 and 20:4n-6 status at birth and their relative postnatal changes, calculated by the difference between status at the end of the feeding period (6 wk of age) and at birth, were assessed. RESULTS: Postnatal changes in the plasma and erythrocyte phospholipids 22:6n-3 and 20:4n-6 were negatively related to their respective concentrations at birth (P < 0.01) and the slopes of the regression lines were not significantly affected by the type of milk ingested. Adjusted mean values for phospholipid 22:6n-3 in nonsupplemented-formula-fed infants and for 20:4n-6 in formula-fed infants decreased significantly more than they did in the other infant groups (P < 0.02). The status at birth and the type of milk ingested explained 33-64% and 7-47%, respectively, of the variability in postnatal changes. CONCLUSIONS: The status of 22:6n-3 and 20:4n-6 at birth in term infants is one of the major determinants of postnatal changes in these fatty acids. This finding indicates that research is required to characterize environmental, genetic, or both factors, which, in addition to maternal diet, could influence fatty acid status at birth.

Arachidonic Acid↗