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Biomedical subjects

D Bourgeois

Publications and source records attributed to D Bourgeois.

At least 55 records · Page 3Linked to original sources
PubMed1996

Caries prevalence in 12-year-old schoolchildren in New Caledonia.

This study reports on the most recent epidemiological survey undertaken in New Caledonia, a French dependency in the South Pacific. Three hundred and twenty-five 12-year-old children were selected from schools using the World Health Organization pathfinder sampling methodology. The results showed a DMFT of 4.09. This places New Caledonia in the 'moderate' category on the World Health Organization scale of caries severity for 12-year-old children. Two oral health risk groups were identified: Melanesian and Wallisian children. Different approaches to promoting oral health in New Caledonia, taking into account local socio-cultural traditions, are proposed.

Child↗
PubMed1994

Epoxy/carbon composite resins in dentistry: mechanical properties related to fiber reinforcements.

Composite carbon/epoxy resin techniques for restorative dentistry have improved with the development of various composite resins classified according to fiber reinforcement, such as short fibers, woven materials, or long unidirectional fibers. This study of the mechanical properties with three-point flexion enabled comparison of the flexural strengths. The modulus of elasticity of different composite resin materials was determined so that the appropriate reinforced composite resin could be selected for specific clinical conditions.

Aniline Compounds↗
PubMed1994

Standard descriptive tables in WHO Oral Health epidemiological studies.

For many years the Oral Health Programme of the World Health Organization has promoted the development of oral health epidemiological surveys. The objective of this article is to make oral health researchers aware of the variables and statistical tables recommended by WHO for the standardization, presentation and comparability of international surveys. The influence of the growing impact of computer technology in providing better knowledge of oral health systems is also discussed in this article.

Adolescent↗
PubMed1993

A highly sensitive lactate editing technique for surface coil spectroscopic imaging in vivo.

A lactate editing sequence based on the use of spin-locking pulses with surface coils is described. The sequence retains more than 90% of the available lactate magnetization and suppresses at least 95% of the lipid signal in a single scan and ca. 99.5% after a simple two step cycle. The technique allows simultaneous observation of lactate and uncoupled metabolites in the range 2 to 3 ppm. The sequence was combined with two-dimensional spectroscopic imaging to obtain a lactate map of an ischemic rat brain in vivo.

Animals↗
PubMed1993

Simultaneous measurement of both lipid and lactate in isolated rat hearts by 1H NMR spectroscopy.

Myocardial lipid and lactate levels are sensitive indicators of biochemical status: lipid levels have been shown to increase in response to high fat diets, disease or metabolic stress and elevated lactate levels are indicative of reduced oxygen supply. Selective measurement of lactate or lipid levels by 1H NMR is not straightforward since both the lactate methyl group and lipid methylene groups resonate at 1.3 ppm. We have overcome this difficulty by employing spectral editing techniques to observe both lipid methylene and lactate methyl resonances, and have measured lipid and lactate levels in perfused rat hearts during control perfusion and in response to metabolic stress. Lactate increased during ischemia and decreased during reperfusion, and the ischemia-induced increase is inhibited by iodoacetate, as expected. In contrast, lipid levels increased during ischemia and remained elevated during reperfusion. Hearts from rats fed high fat diet show elevated lipid levels during control perfusion. Data obtained by 1H NMR are consistent with biochemical data, validating the technique.

Animals↗
PubMed1993

The application of the theoretical model WHO/FDI planning system to an industrialised country: France.

The results of the application of the WHO/FDI planning system to a specific situation in an industrialised country provide valid arguments in favour of its use. It is shown to be an aid to planners when estimating oral health personnel requirements and emphasises the necessity of obtaining basic information on the oral health status and demand for treatment in industrialised countries. The strength of the system lies in the fact that it enables the user to forecast requirements, by age cohort and by type of care, while at the same time including socio-economic variables which have a major influence in industrialised countries with moderate caries levels. This flexibility of use enables the system to be adapted, if necessary, or even improved, according to the constraints which may result from a specific situation analysis.

Adolescent↗
PubMed1992

Phasing spin-echo-acquired 31P spectroscopic images using complex conjugate data reversal.

A simple method has been developed for phasing 31P spectroscopic images acquired with short echo-time (1-2 ms) spin-echo sequences. The technique is based on reconstructing complete echoes in the time domain by the reversal of the complex conjugate of the data. After Fourier analysis, a magnitude reconstruction is used, which no longer broadens the lines. Advantages of the method compared to other phasing procedures are discussed.

Animals↗
PubMed1992

Evaluation of the World Health Organisation pathfinder methodology for oral health surveys in industrialised countries.

The aim of this study was to carry out a survey using the pathfinder methodology developed by the World Health Organisation for international surveys and to compare the results (DMFT, DT, MT, FT) with those obtained from a national survey in France. The statistically significant difference observed between the results of the DMFT and DT indices obtained by using the two methods does not affect the classification of France at the 'moderate' level on the World Health Organisation scale for caries prevalence at the age of 12 years. The observed DMFT difference is an argument in favour of using the World Health Organisation pathfinder methodology, as it provides a satisfactory degree of precision on the oral health status of a population for planning purposes.

Child↗
PubMed1992

[Evaluation of the orofacial and dental status of a population of leprosy patients treated with multidrug therapy in Senegal].

The orofacial lesions of untreated leprosy have long been known. Our study concentrated on the bucco-dental and facial status of 97 leprosy patients given multidrug therapy. The number of decayed teeth and of teeth missing due to extraction proved high. Clinical manifestations of leprosy in the facial region are, however, rare and lesions of the oral mucosa, while more frequent, always exhibit scarring.

Adolescent↗
PubMed1991

Very slow flow imaging.

Two methods allowing imaging of very slow coherent flows are presented. The first method is based on the use of a radiofrequency field gradient. The second method is based on the use of gradients of the main field. Both methods include suppression of signal from stationary spins. A flow contour map is obtained which allows quantitative determination of velocity. The methods were proved to be efficient to image velocities as low as 10 microns.s-1.

Humans↗
PubMed1991

Proton spectroscopic imaging: a tool for studying intracerebral tumor models in rat.

Water-suppressed 2D 1H spectroscopic imaging was used with surface coils to study in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ. To achieve slice selection without a chemical-shift artifact, we exploited the depth pulse properties of a spin-echo sequence. In order to give a spectral response which is independent of the position, the water suppression was achieved by using a spin-locking excitation and a binomial refocusing pulse. Spectroscopic images were obtained with an in-plane resolution of 1.1 X 1.1 mm and a slice thickness of roughly 3 mm. The growing of the tumor induced dramatic modifications in the proton spectra, including a nearly complete loss of N-acetyl aspartate, an increase of the 1.3-ppm peak, an increase in choline, and a decrease in creatine. The results demonstrate the potential of spectroscopic imaging in the study of intracranial tumor models in rats.

Animals↗
PubMed1991

Evaluation of the utilization of complex periodontal care in an industrialized country with a national health insurance.

This paper presents an analysis of the utilization of periodontal care, subject to prior agreement, over a period of 3 months. It concerns insured persons covered by the Caisse Primaire d'Assurance Maladie de Lyon, which represents 5 per cent of the French population. It details 516 cases. The mean (+/- SD) age of the persons requiring care was 43 +/- 12.6 years; their dental health was good, and 58 per cent were women. The nature and geographical locality of the periodontal treatments are given and 1323 procedures are listed, with a high proportion of gingivectomies and flap operations.

Adult↗