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Biomedical subjects

A Fontaine

Publications and source records attributed to A Fontaine.

At least 37 records · Page 2Linked to original sources
PubMed1999

Physicians' recognition of the symptoms experienced by HIV patients: how reliable?

To assess how well physicians recognize common symptoms in HIV patients and identify factors associated with symptom recognition, a multicenter cross-sectional survey was performed in a random sample of 118 hospitalized and 172 ambulatory HIV patients, and their attending physicians. Patients' reports of 16 different symptoms were compared to physicians' reports of whether each symptom was present and/or specific treatments prescribed. Overall, fatigue, anxiety, skin problems, fever, and weight loss were more often recognized by physicians than other symptoms. Agreement between patients and physicians was poor to moderate, with Kappa statistics ranging from 0.17 (dry mouth) to 0.58 (fever). Recognition was independently more likely for ambulatory patients (adjusted odds ratio 1.69, P < 0.001) and for patients seen as sicker (adjusted odds ratio 1.88, P < 0.001). Appropriate symptom management requires improved symptom recognition. More systematic clinical examinations, including attentive patient interview, are needed.

Adult↗
PubMed1999

Diurnal variations in keratometry and refraction with intracorneal ring segments.

PURPOSE: To study refraction variations during the day in eyes with intrastromal corneal ring segments (ICRS) to correct low myopia. SETTING: Monticelli Clinic, Marseille, France. METHODS: Thirteen eyes with ICRS were included in the study; the ICRS was explanted from 3 eyes because of undercorrection. The minimum follow-up in all eyes was 1 year. The same observer measured refraction and keratometry at 9:00 AM, 1:00 PM, and 7:00 PM with the same autokeratorefractometer. To validate the analysis method, these eyes were compared with a group of emmetropic control eyes that had not had surgery and with a group of eyes that had photorefractive keratectomy for a similar degree of myopia. All measurements were done under the same conditions. RESULTS: After 1 year, the ICRS eyes showed a tendency toward an evening myopic shift. This was confirmed by the objective keratometry study, which showed variations closely correlated with the myopia observed. These phenomena were not observed in the other groups. CONCLUSION: The ICRS had satisfactory predictability in eyes with up to -3.50 diopters of myopia. However, the evening myopic shift appeared similar to that observed after radial keratotomy.

Adult↗
PubMed1999

Evolution of the French public's knowledge and attitudes regarding postoperative pain, cancer pain, and their treatments: two national surveys over a six-year period.

UNLABELLED: Pain management has become a notable feature of public health policy and mass media communication in France over the past few years. To assess the evolution of the knowledge and attitudes of the French population with respect to pain management and morphine use, telephone surveys using similar questionnaires were conducted in 1990 (n = 1001) and 1996 (n = 1006). The proportion of respondents who would take pain management adequacy into consideration when selecting a surgical facility increased from 52% to 81% (P < 0.001), as did the proportion who associated morphine with pain treatment (from 44% to 80%; P < 0.001) or who would not be afraid of becoming addicted to morphine after it had been prescribed for pain relief (from 26% to 69%; P < 0.001). However, the proportion of respondents who agreed that morphine can be prescribed to patients with pain increased only slightly. In 1996, 58% of the respondents believed that their knowledge had improved over the past 5 yr and associated this improvement first with television, followed by written press articles and by interaction with physicians. Increased awareness of pain management possibilities among the public may generate increased demand on health professionals to provide adequate and precise information addressing each patient's needs. IMPLICATIONS: The results of two representative surveys conducted over a 6-yr interval show significant improvements of knowledge and attitudes regarding pain and its management in the French general population. However, these results point to the need for additional specific information that should be provided through patient-physician interactions.

Adolescent↗
PubMed1999

The value of internal carotid systolic velocity ratio for assessing carotid artery stenosis with Doppler sonography.

OBJECTIVE: The purpose of this study was to assess the value of the ratio between the internal carotid systolic velocity (ICSV) at the carotid bulb and the distal internal carotid systolic velocity (DICSV) for the detection of carotid artery stenosis. SUBJECTS AND METHODS: Two hundred eleven patients were enrolled in a prospective study comparing several Doppler measurements with carotid angiography. The following spectral measurements were obtained with Doppler sonography: ICSV/DICSV ratio, ICSV, ICSV/common carotid systolic velocity (CCSV) ratio, and internal carotid (end) diastolic velocity (ICDV). Receiver operating characteristic curves were generated for two groups: the first group being 365 carotid arteries for which all Doppler measurements were successfully obtained and the second being a subgroup of 258 carotid arteries for which an ICSV of 100 cm/sec or greater was present. RESULTS: In the group of 365 carotid arteries, the ICSV/DICSV ratio improved the detection of stenosis of 60% or greater as compared with the ICDV (p = .03). In 258 carotid arteries with an ICSV of 100 cm/sec or greater, the ICSV/DICSV ratio allowed for a better angiographic correlation for identifying stenoses of 60% or greater and 70% or greater as compared with ICSV (p = .006 and .023, respectively), ICSV/CCSV (p = .0013 and .003, respectively), and ICDV (p = .0015 and .020, respectively). CONCLUSION: Using the ICSV/DICSV ratio for the Doppler detection of carotid artery stenosis is advantageous when the ICSV is 100 cm/sec or greater.

Aged↗
PubMed1999

[Diurnal variations of refraction and keratometry after intracorneal rings].

UNLABELLED: Within a European evaluation, we participated in the study of ICRS on low myopia. During the period of observation, subjective refraction variations in the day were underlined. This phenomenon remains to be specified. MATERIAL AND METHODS: Thirteen eyes were included in the study, 3 were explanted because of under-correction. The minimum follow-up is one year for all eyes. The same observer measured refraction and keratometry in all eyes on the same day at 9:00 am, 1:00 p.m. and 7:00 p.m., with the same automatic autokeratorefractometer. To validate the analysis method, these patients were compared with a group of emmetropic control eyes never operated on and with a group of eyes operated on with a PRK for similar myopia. All measurements were done under the same conditions. RESULTS: After one year, a tendency to evening myopisation was noticed in ICRS eyes and confirmed by the objective keratometry study showing variations closely correlated with the myopia observed. These phenomena were not observed in the two other groups. DISCUSSION: The examination technique was validated by the absence of variation observed on normal eyes. The tendency to diurnal myopisation is rather constant on the whole population studied with a more or less important degree from patient to patient. These observations never reported in the literature, deserve to be confirmed on other sites. CONCLUSION: In this study ICRS allowed to correct low myopia with a satisfactory predictability up to -3.50 D. However, the appearance of an evening myopisation recalls that observed after radial keratotomy. Complementary studies are necessary to explain the intimate mechanism of this phenomenon.

Adult↗
PubMed1999

[Reliability and validity of the French version of the first part of the Appropriateness Evaluation Protocol (AEPf): pertinent criteria of hospitalization stay].

BACKGROUND: The Appropriateness Evaluation Protocol (AEP) is a tool used to identify hospitalization days that are appropriate with respect to simple technical criteria, and the reasons for hospitalization days that do not meet these criteria. The goal of the study was to validate the clinical criteria of AEPf, required for identifying the reasons which explain these inappropriate hospital days. METHODS: The validity of a French version of criteria of appropriateness (AEPf) was assessed in a sample of 502 hospital days in medical and surgical wards of six French teaching hospitals. The reliability of the AEPf-based conclusions was studied by the measure of the concordance between two independent measures of AEPf for the same hospital day. Validity of AEPf was studied by the measure of the concordance between AEPf-based conclusions and the judgments of physicians using implicit criteria to assess the necessity of the hospital day studied. The degree of concordance was estimated by the Kappa coefficient. RESULTS: AEPf reproducibility was high (Kappa coefficient: 0.81; 95% confidence interval (95% CI): 0.76-0.87). Validity was also high (Kappa coefficient: 0.61; 95% CI: 0.53-0.68). CONCLUSION: The French version of the AEP was thus shown to be both reliable and valid to identify hospitalisation days appropriate with respect to hospital's technical equipment and specific resources. However, the reproducibility of the assessment of reasons for hospital days that did not meet AEP criteria will require a validation.

Chi-Square Distribution↗
PubMed1998

High-focusing Bragg-Crystal polychromator design for energy-dispersive X-ray absorption spectroscopy.

The design of a highly focusing profiled Si(111) Bragg crystal polychromator for dispersive EXAFS (extended X-ray absorption fine structure) experiments is described. The contour of the crystal has been optimized to give the best focus over the full 4-13 keV energy range. The profile optimization has been improved taking into account all the degrees of freedom of the geometry and the results of X-ray tracing simulations. The profile of the crystal has been calculated to take full advantage of the new possibilities given by the undulator source and the optics of beamline ID24 at the European Synchrotron Radiation Facility. Full spot sizes have been measured to be between 20 and 40 microm in the 5-12 keV energy range. These values compare well with X-ray tracing simulations and are the smallest spots ever obtained with energy-dispersive EXAFS optics, keeping, however, a wide enough energy bandpass for most X-ray absorption spectroscopy experiments.

Journal Article↗
PubMed1998

A scattering filter for energy-dispersive optics.

A filtering technique to remove parasitic scattering from X-ray absorption spectra that are acquired in energy-dispersive mode has been developed and tested at the European Synchrotron Radiation Facility. The improved set-up removes small-angle scattering of the sample or the windows of sample cells which may spoil the energy resolution or reduce the intensity of prominent features in the absorption spectrum, such as the white line at the Pt L(III) edge. The sample is placed behind the curved monochromator and between two plane perfect crystals in the Bonse-Hart configuration. The dispersion of the Bonse-Hart double-crystal camera is matched to the dispersion of the curved monochromator by inclining the scattering planes of the two optical elements against each other.

Journal Article↗
PubMed1998

Nanosecond-resolved XMCD on ID24 at the ESRF to investigate the element-selective dynamics of magnetization switching of Gd-Co amorphous thin film.

The one-bunch filling mode of the ESRF is combined with a microcoil to generate a pulsed-magnetic-field pump phased with respect to the probe that is given by the bunch of photons emitted each turn (357 kHz). Nanosecond-resolved X-ray magnetic circular dichroism (XMCD) is carried out. Besides the microcoil, the two other key-elements are the energy-dispersive XAS spectrometer, which yields parallel data acquisition, and the diamond-based quarter-wave plate, which tunes the helicity of the photon alternatively left and right.

Journal Article↗
PubMed1998

Two recent developments in XMCD.

This paper reports on two new technical developments concerning sample environments for X-ray magnetic circular dichroism (XMCD). The first measurements under high pressures of up to 30 GPa are described. The difficulties of combining the techniques of high pressure and XMCD are commented on. The second development involves the use of a fast-switching magnetic field. A new superconducting device is used to perform XMCD measurements on paramagnetic compounds in magnetic fields of up to 6 T. The small amplitude of the XMCD signal imposes, for a given signal-to-noise ratio, a noise less than a few 10(-5). The signal-to-noise ratio is improved by the use of a series of acquisitions, switching the magnetic field between each acquisition. A very fast switching mechanism has been built based on mechanical rotation of a superconducting coil, with the sample kept in place inside the coil. The XMCD signals at the L(II,III)-edges of paramagnetic rare-earth compounds have been measured at 4.5 K in fields of up to 6 T with a switching time of 11 s.

Journal Article↗
PubMed1998

Validation of the three-dimensional acquisition mode in positron emission tomography for the quantitation of [18F]fluoro-DOPA uptake in the human striata.

Three-dimensional (3D) positron emission tomography (PET) is attractive for [18F]fluoro-DOPA studies, since the sensitivity improvement is maximal for radioactive sources located in central planes, which is usually the case for the human striata. However, the image quantitation in that mode must be assessed because of the nearly threefold increase in scattered coincidences. We report the results of [18F]fluoro-DOPA studies performed on six normal volunteers. Each one was scanned in the 3D and two-dimensional (2D) modes on the same tomograph. The quantitation in the 3D and 2D modes was compared for a Patlak graphical analysis with the occipital counts as the input function (Ki) and a striatooccipital ratio analysis. We find that, in 3D PET, a scatter correction is required to preserve the same quantitation as in 2D PET. When the 3D data sets are corrected for scatter, the quantitation of the [18F]fluoro-DOPA uptake, using the Patlak analysis, is similar in the 2D and 3D acquisition modes. Conversely, analysis of the striatooccipital ratio leads to higher values in 3D PET because of a better in-plane resolution. Finally, using the 3D mode, the dose injected to the subjects can be reduced by a factor greater than 1.5 without any loss in accuracy compared to the 2D mode.

Adult↗
PubMed1998

Lateralization of speech and auditory temporal processing.

To investigate the role of temporal processing in language lateralization, we monitored asymmetry of cerebral activation in human volunteers using positron emission tomography (PET). Subjects were scanned during passive auditory stimulation with nonverbal sounds containing rapid (40 msec) or extended (200 msec) frequency transitions. Bilateral symmetric activation was observed in the auditory cortex for slow frequency transitions. In contrast, left-biased asymmetry was observed in response to rapid frequency transitions due to reduced response of the right auditory cortex. These results provide direct evidence that auditory processing of rapid acoustic transitions is lateralized in the human brain. Such functional asymmetry in temporal processing is likely to contribute to language lateralization from the lowest levels of cortical processing.

Acoustic Stimulation↗
PubMed1998

[Research-action on medical and social management of uninsured pregnant women].

INTRODUCTION: Perinatal morbidity is increased among women without health insurance and/or receiving poor antenatal care. The objectives of this study were to estimate the prevalence of such situations, to analyze underlying social conditions, to identify possible means to secure health insurance and to assess the impact of the absence of health insurance on antenatal care and pregnancy outcomes. MATERIAL AND METHODS: All pregnant women without health insurance during one calendar year were included. Those who delivered a live child were compared with a control group of women with health insurance who delivered a live child until the date of the last delivery for uninsured women. Statistical analyses were conducted to describe the characteristics of uninsured women and to identify risk factors for poor antenatal care and pregnancy outcomes. RESULTS: A total of 259 uninsured women were enrolled, including 201 (78%) foreigners the majority of whom had resided in France for more than one year; 205 were followed-up and delivered in our hospital, including 192 live births. The social context of uninsured French women was worse than that of foreign uninsured women. Health insurance was obtained for 85% (173/205). Overall, the absence of health insurance was associated with increased risks for poor antenatal care. Being uninsured and receiving poor antenatal care was associated with an increase in the incidence of intra-uterine growth failure. Post-term deliveries were more frequent among women with poor antenatal care. CONCLUSIONS: Improving antenatal care and health insurance coverage could help decrease perinatal morbidity, given the current increase in the number of women with social risk factors. It seems essential that all women obtain access to public maternity wards, and that these wards develop effective social services working in concert with ambulatory health and social workers.

Birth Weight↗
PubMed1997

Underestimation and undertreatment of pain in HIV disease: multicentre study.

OBJECTIVE: To measure the prevalence, severity, and impact of pain on quality of life for HIV patients; to identify factors associated with undertreatment of pain. DESIGN: Multicentre cross sectional survey. SETTINGS: 34 HIV treatment facilities, including inpatient hospital wards, day hospitals, and ambulatory care clinics, in 13 cities throughout France. SUBJECTS: 315 HIV patients at different stages of the disease. MAIN OUTCOME MEASURES PATIENTS: recorded presence and severity of pain and rated quality of life. Doctors: reported disease status, estimate of pain severity, and analgesic treatment ordered. RESULTS: From 30% (17/56) of outpatients to 62% (73/118) of inpatients reported pain due to HIV disease. Pain severity significantly decreased patients' quality of life. Doctors underestimated pain severity in 52% (70/135) of HIV patients reporting pain. Underestimation of pain severity was more likely for patients who reported moderate (odds ratio 24) or severe pain (165) and less likely for patients whose pain source was identified or who were perceived as more depressed. Of the patients reporting moderate or severe pain, 57% (61/107) did not receive any analgesic treatment; only 22% (23/107) received at least weak opioids. Likelihood of analgesic prescription increased when doctors estimated pain to be more severe and regarded patients as sicker. CONCLUSIONS: Pain is a common and debilitating symptom of HIV disease which is gravely underestimated and undertreated.

Adolescent↗
PubMed1997

A three-component force vector cell for in vitro quantification of the force exerted by the papillary muscle on the left ventricular wall.

Recent clinical studies indicate that functional mitral regurgitation, which is a common complication in patients who suffer from ischemic heart disease, is related to an increase in the tethering forces acting on the mitral valve leaflets. Alterations in the valvular assembly, displacement of the papillary muscles or dilatation of the mitral valve annulus can disrupt the normal force balance on the mitral leaflets and result in an abnormal coaptation geometry with incomplete mitral leaflet closure. The force balance imposed on the mitral leaflets is created by the coapting forces generated by the transmitral pressure difference and the tethering forces at the leaflet attachments. A unique force vector cell capable of accurately measuring the three-component force vector applied by the papillary muscle on the left-ventricular wall was designed and manufactured to permit quantification of the alteration in the force balance acting on the mitral leaflets, and to allow for the study of the influence of papillary muscle displacement on mitral regurgitation.

Animals↗
PubMed1997

Toward quality improvement in a French hospital: structures and culture.

This paper describes the evolution of quality improvement efforts over the past decade in a 600-bed French teaching hospital, after reviewing some characteristics of the French hospital system. The sequential attempts to improve drug dispensation illustrate the evolution of quality improvement efforts. Initial studies conducted in voluntary medical wards led to the modification of traditional prescription forms. Resulting improvements were presented in Evaluation Committee meetings, inducing other wards, to undertake similar changes on their own. A more systemic program currently is underway. The success of initial efforts can be credited to the willingness of physicians and nurses to engage in changes when the need for change was evident in their daily work experience, in spite of the questionable validity of some of the original findings. Focusing on systemic processes rather than on individual faults allowed this involvement. Reassessing the validity of so-called medication errors also highlighted the importance of careful process analysis, which should be stressed during the development of quality assurance procedures. The variability inherent in clinical conditions calls for a flexible, outcome-oriented approach, as used in quality improvement methods. Quality improvement efforts are spreading throughout the hospital. However, diffusion of change from motivated work groups to the larger community remains a challenge. To obtain a consistent performance level across all parts of the organization, and to avoid losing impetus due to uncoordinated efforts, innovation must become a consistent feature of the hospital structure.

Drug Utilization Review↗
PubMed1997

Renal chromophobe cell carcinoma and oncocytoma. A comparative morphologic, histochemical, and immunohistochemical study of 124 cases.

BACKGROUND: Renal oncocytoma has several features that overlap with other renal neoplasms, including the eosinophilic subtype of chromophobe cell carcinoma. In fact, strict criteria for renal oncocytoma have not been well defined and remain a matter of controversy. Ultrastructural studies or sophisticated methods such as flow cytometry and cytogenetic techniques can be of great use in distinguishing the two tumors, but are difficult to propose as routine methods because of their limited availability. OBJECTIVE: To further characterize the histologic criteria of these tumors, we undertook a retrospective study to define the utility of routinely available histochemical and immunohistochemical techniques. DESIGN AND SETTING: Twenty-one cases of chromophobe cell carcinoma, eosinophilic subtype, and 103 cases of oncocytoma were tested with histochemical (Perls, periodic acid-Schiff, and Hale's colloidal iron) and immunohistochemical (peanut agglutinin antigen and UEA-1 for lectins; cytokeratin KL1, epithelial membrane antigen, vimentin, S100 protein, and lysozyme) staining. RESULTS: The antibodies tested and the histochemical staining using Hale's colloidal iron allowed eosinophilic chromophobe cell carcinoma to be distinguished by its characteristic reaction pattern. Seventy-six percent of the chromophobe cell carcinomas showed a microvacuolated pattern, and 89% of the renal oncocytomas showed an apical positivity with Hale's colloidal iron staining (P < .01). Peripheral cell accentuation reactivity for cytokeratin KL1 was observed in 66% of the chromophobe cell carcinoma cases, and apical cytoplasmic positivity was observed in 37% of the renal oncocytoma cases (P = .01). Significant patterns were observed with anti-epithelial membrane antigen and anti-peanut agglutinin antigen antibodies (P = .05 and P = .01, respectively). Positive reactions for vimentin, S100 protein, lysozyme, and UEA-1 were not significant characteristics. CONCLUSION: Our study demonstrated that a precise morphologic description associated with simple histochemical and immunohistochemical techniques provides sufficient criteria for a high level of discrimination between the eosinophilic subtype of chromophobe cell carcinoma and renal oncocytoma.

Adenocarcinoma↗