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J Liénard

Publications and source records attributed to J Liénard.

17 recordsLinked to original sources
PubMed2002

Prevalence of methicillin-resistant Staphylococcus aureus carriage at the time of admission in two acute geriatric wards.

Studies on methicillin-resistant Staphylococcus aureus (MRSA) in the elderly have been concerned with patients hospitalized in nursing homes or long-term care facilities. Our objective was to estimate the prevalence of MRSA at the time of admission in two acute geriatric wards with high endemic MRSA incidence in a French teaching hospital. A prospective screening of MRSA carriers was conducted by swabbing nares and wounds during five weeks for all patients on the day of admission. For each patient demographic, administrative, clinical and therapeutic data were recorded. Their associations with MRSA carriage were studied by logistic regression analysis. On the day of admission, 35 patients (14.6%) were MRSA carriers. Variables independently associated with carriage were hospitalization within the six last months (OR = 4.64; P < 0.001) and the existence of wounds or bedsores (OR = 2.864; P = 0.02). The high prevalence of MRSA carriage at the time of admission could explain in part the high incidence of MRSA in these wards. A systematic selective screening targeted on patients with high risk of carriage should be helpful to implement barrier precautions and reduce cross-transmission.

Aged↗
PubMed1998

Normal left ventricular volumes and ejection fraction: assessment with quantitative digital cardioangiography.

The aim of this study was to assess the accuracy and precision of a digital angiography system, the General Electric DX system, as compared to conventional left ventricular cineangiography. After a phantom study, sixty patients with normal coronary arteries and normal left ventricles (LV) were studied. The LV contours were manually traced from raw or subtracted digital runs and from the cine films in an independent manner. A regression formula was used to adjust the DX derived data to the cine film results (Vcorrected = 0.693 Vmeasured +8.65 ml). There was an excellent correlation between the two methods in the end-diastolic volume index (r = 0.97, sd = 4.2 ml/m2), the end-systolic volume index (r = 0.95, sd = 2.7 ml/m2), the stroke volume index (r = 0.93, sd = 4.1 ml/m2), and the ejection fraction (r = 0.85, sd = 3.45%). We conclude that manual tracing of LV contours from either raw or subtracted digital images provides reliable and accurate measurement of LV volume and ejection fraction.

Adult↗
PubMed1998

Biochemical effects of calcium supplementation in postmenopausal women: influence of dietary calcium intake.

We studied the biochemical effects of calcium supplementation during a 2-mo course in postmenopausal women (x +/- SD: 64 +/- 5 y of age and 14.5 +/- 6.7 y since menopause). The effects on calcium homeostasis and bone remodeling were assessed after 1 and 2 mo of daily administration of either calcium carbonate (1200 mg elemental Ca/d, n = 60) or a placebo (n = 56). The daily dietary calcium intake assessed before the beginning of calcium supplementation was 786 mg/d. We found a significant inverse relation between baseline intact parathyroid hormone (iPTH) and dietary calcium intake before supplementation (r = -0.48, P = 0.0002). A significant increase in urinary excretion of pyridinoline was observed when the dietary calcium intake was lower than the median value. Calcium supplementation resulted in a significant increase in 24-h urinary calcium (39%, P < 0.02) and a significant reduction of bone alkaline phosphatase at 2 mo and of all bone-resorption markers (hydroxyproline, pyridinoline, and deoxypyridinoline) at I and 2 mo without significant changes in 44-68 PTH fragments or iPTH concentrations. When the dietary calcium intake was low (mean +/- SD: 576 +/- 142 mg/d), calcium supplementation was responsible for a greater increase in urinary calcium excretion and a greater decrease in markers of bone turnover. The greatest variations were observed for deoxypyridinoline at 1 and 2 mo (-18.5%, P < 0.05) and for pyridinoline at 1 mo (-16.3%, P < 0.01). Two months of calcium supplementation in postmenopausal women was efficient in reducing markers of bone turnover, with a greater effect in women with a low dietary calcium intake.

Aged↗
PubMed1996

Parameters that influence accuracy and precision of quantitative coronary arteriography.

The limited resolution of any imaging system causes edge blurring of objects acquired with X-ray. In digital angiography, this effect combined with noise gives rise to systematic and random errors in the determination of vessel dimensions. The influence of bandwidth limitation on the estimation of tube diameter is established by a theoretical approach: it leads to over and underestimations of catheter and vessel diameter dimensions. Therefore a correction is proposed that counterbalances the point spread function (PSF) offset. The residual inaccuracy and the variability of measurement of phantom tubes are analyzed and evaluated in controlled conditions. Some of the parameters which govern their extent are identified: field-of-view, catheter size, concentration of contrast agent.

Coronary Angiography↗
PubMed1996

Can we optimize our angiographic views every time? Qualitative and quantitative evaluation of a new functionality.

RATIONALE AND OBJECTIVES: For determining the optimum angulations of the x-ray beam with respect to the vascular morphology of a given patient, the authors present a solution combining a single-plane angiographic system and a dedicated procedure. METHODS: The clinical evaluation of the vessel profiling acquisitions focuses on qualitative appraisal and quantitative analysis of conventional and optimum projections. RESULTS: The qualitative evaluation demonstrates the pitfall for an operator to discern optimum from conventional projections. The 70% of preferences for vessel profiling bear witness to the constraints imposed occasionally by the optimum angulations, which may be impracticable for various reasons. However, vessel profiling yields lesions inspection at an optimum view, free of geometric foreshortening. Moreover, there is less risk of superimposition with other branches. From a quantitative standpoint, vessel profiling unveils the lesion with a length significantly longer than in conventional view. CONCLUSIONS: Vessel profiling offers a qualitative optimization of angiographic images and more exact quantitative analysis.

Angiocardiography↗
PubMed1996

[Seroprevalence of viral hepatitis A in at the Amiens University Hospital].

OBJECTIVES AND METHODS: The epidemiology of viral hepatitis A has been evolved in the past few years, resulting in an increasing number of people without immunity to this virus. Health care workers are usually considered to be a group at risk of contamination by hepatitis A. A sero-epidemiologic study was performed in 525 members of the Pediatry, Gastroenterology, Internal medicine, Digestive radiology, kitchen and maintenance department staffs in the Amiens University Hospital. The aim of this study was to describe the epidemiology of hepatitis A and to estimate the level of occupational hazard it represents in the hospital. RESULTS: Age, low education level, country of origin in an endemic region and more than 2 siblings or children were significantly associated with the presence of anti-HAV antibodies. The prevalence of 50% was similar to that observed in other hospitals, but lower than that found in the general population. Seroprevalence was not higher in departments exposed to stools (Pediatry, Digestive endoscopy and laboratories) than in others. A higher rate of seroprevalence was observed in kitchen and maintenance staffs than in medical, laboratory and Radiology staffs, in Internal medicine than in the Gastroenterology Department, and in the laboratory than in Radiology Department. These differences disappeared after adjustment for extraprofessional parameters which appeared to be most important for hepatitis A epidemiology. CONCLUSIONS: The hospital occupational hazard for hepatitis A virus did not seem higher than that observed in the general population.

Adult↗
PubMed1996

[Optimization of coronary angiographic views. Qualitative and quantitative evaluation of a new system].

A coronary angiographic view is said to be "optimal" when the directing radius of the X-ray beam is perpendicular to the long axis of a stenosis. The object was to fulfill two criteria: 1) the accurate calculation of the spatial orientation of the stenosis to obtain the optimal position, 2) rapid and optimal positioning of the angiographic material with easy rotation around the axis of the stenosis. Two combined solutions were proposed:the Advantx L/C (GE Medical systems) angiocardiographic system with three motorised axes of rotation and a specific software. This software takes into account two longitudinal axes of the stenosis traced by the operator in two conventional incidences and then determines the angles of optimal positioning (accuracy +/-5 degrees). During 97 consecutive coronary angiograms, the software was used in 23 cases (24%) and judged to be useful in 16 cases (70%). In 2 of the 23 cases (8%) the mechanical angles calculated could not be used, the incidences being incompatible with the patient's position. During the angiograms, the best two images of stenosis (one conventional, one optimal) were retained to form a pair of images. Eight observers analysed 37 pairs of images shown side by side. 65% of the images selected from each pair as being the best descriptive appearance of the stenosis came from the optimised system. During quantitative analysis, only the length of stenosis differed statistically between the two modes of acquisition (1.26 +/- 0.36 mm; p = 0.0014). This system is useful during coronary angiography for providing optimal views of stenosis free from any geometric distorsion and without superimposition of adjacent branches.

Coronary Angiography↗
PubMedDate not supplied

Real-time distortionless high-factor compression scheme.

Nowadays, digital subtraction angiography systems must be able to sustain real-time acquisition (30 frames per second) of 512 x 512 x 8 bit images and store several sequences of such images on low cost and general-purpose mass memories. Concretely, that means a 7.8 Mbytes per second rate and about 780 Mbytes disk space to hold a 100-s cardiac examination. To fulfill these requirements at competitive cost, a distortionless compressor/decompressor system can be designed: during acquisition, the real-time compressor transforms the input images into a lower quantity of coded information through a predictive coder and a variable-length Huffman code. The process is fully reversible because during review, the real-time decompressor exactly recovers the acquired images from the stored compressed data. Test results on many raw images demonstrate that real-time compression is feasible and takes place with absolutely no loss of information. The designed system indifferently works on 512 or 1024 formats, and 256 or 1024 gray levels.

Angiography, Digital Subtraction↗