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O Plaisant

Publications and source records attributed to O Plaisant.

At least 19 recordsLinked to original sources
PubMed2007

Perception of medical students towards the clinical relevance of anatomy.

Recent developments worldwide in medical curricula have often led to major cuts in the teaching of human anatomy. Indeed, it is perceived by some that gross (topographical) anatomy has an exaggerated importance in the initial training of doctors. The value of anatomy consequently has frequently been considerably diminished within medical curricula that have reduced factual content. To date, however, there have been no objective studies into the perceived relevance of anatomy to clinical medicine that have aimed to quantify the attitudes of medical students. On the basis of responses to an attitude analysis questionnaire devised according to the precepts of Thurstone and Chave (The Measurement of Attitude: A Psychophysical Method and Some Experiments with a Scale for Measuring Attitude Toward the Church. Chicago, IL: University of Chicago Press, 1951), we investigated the perception of medical students at Cardiff and Paris towards the importance of gross anatomy to clinical medicine. This was undertaken during the early stages of their studies (when they were newly-admitted to university and were about to commence anatomy courses), immediately after finishing their anatomy courses, and later in the final year of medical studies. The results suggest that, even where there might be geopolitical and cultural backgrounds, students at all stages of their medical course share with professional anatomists the view that anatomy is a very important subject for their clinical studies. Thus, contrary to the unquantified beliefs of those who are sceptical about the purpose and value of anatomy in an undergraduate medical curriculum, the students themselves do not appear to share such beliefs.

Anatomy↗
PubMed2006

[3D modeling in the field of morphology: methods, interest and results].

The aim of this paper is to show the major role played by the new computerized imaging tools available today in the fields of morphology and anatomy. For anatomical studies or educational purpose, they enhance the classical techniques. The 3D reconstruction, already used in daily clinical practice, will be the basis for computation of validated volumetric protocols enhancing our diagnosis and prognosis means. It is also a fantastic educational tool: the interactivity makes it simple, efficient, attractive and easily accessible and diffusable. For the research, mathematical modeling of embryogenesis and morphogenesis using finite elements method will open new ways for biomecanics and a dynamic quantification approach.

Computer Simulation↗
PubMed2004

Going back to dissection in a medical curriculum: the paradigm of Necker-Enfants Malades.

In 1999, we first reported on various methods of teaching anatomy subsequent to visits to a variety of medical schools in the United States and Europe. We compared the number of contact hours for lectures, dissection classes and tutorials and provided different models for the teaching of anatomy. With respect to the nine French medical schools surveyed, it is clear that the French model is characterized by being lecture-orientated (time in lectures > time in tutorials > time spent on dissection). For the American model (also in the UK and some other parts of Europe), the training is often characterized by being dissection-based (time spent on dissection > time in lectures > time in tutorials; 10 medical schools surveyed). Exceptionally, in one Australian school, time in tutorials exceeds time in lectures (dissection = 0). The differences between the French and American models relate to teaching aims-where dissection predominates, the aims are not just the learning of anatomical facts but include practical skill acquisition and experiential learning. In 2001, to help us change the methods of teaching of anatomy in our medical school at CHU Necker-Enfants Malades (Paris V, France), we asked other French medical schools (and some foreign schools) to suggest ways of organizing anatomy training within certain time constraints. In this paper, we present the answers received. The responses received were of two kinds: (1) those providing a description of the anatomy teaching in their own medical school; (2) those providing a system for organizing the teaching if we, in Paris, have 120 hours in total to teach gross anatomy (except neuroanatomy). In the latter case, a considerable variety of different, and innovative, alternative schemes were suggested that are described in this article.

Anatomy↗
PubMed2003

Morphometry by computerized three-dimensional reconstruction of the hypogastric plexus of a human fetus.

The histological study of the plexus hypogastricus inferior (hypogastric plexus) of a human fetus does not permit the direct appreciation of its spatial configuration and its complicated relations. Developments in the field of computer science and three-dimensional (3D) reconstruction from serial histological sections have allowed a precise description of its morphometry and relations. The histological sections which were used came from the "Rouvière" collection of the Institute of Anatomy in Paris. A personal computer (IMAC) system of image analysis with reconstruction software was used. Serial pelvic histological sections were directly digitized from the slides. Image treatment and reconstruction were done with manual methods. The 3D reconstruction of the hypogastric plexus, the nerves, the pelvic skeleton and viscera were done. The hypogastric plexus and its topographic relations with the other organs were visualized and studied in three dimensions, and its morphometry was studied. The direct acquisition of the images from the slides allowed excellent high-quality digital images to be obtained. However, manual processing for the reconstruction was time-consuming. At first, the reconstruction of the various pelvic structures was done separately for each organ. Then the structures were visualized all together. Thus, the hypogastric plexus could be examined under various incidences with each organ. The virtual images obtained show new details of the topographic relations and improve knowledge of the precise innervation of the pelvic organs.

Female↗
PubMed2002

The human lumbar anterior epidural space: morphological comparison in adult and fetal specimens.

To increase our understanding of the clinical anatomy of the epidural space, the human lumbar anterior epidural space was studied morphologically and developmentally. Histological transverse sections of human lumbar spines were taken at the level of the intervertebral disc and the vertebral body in adult specimens and in fetuses aged 13, 15, 21, 32 and 39 weeks (menstrual age). At 13 weeks, connective tissue filled the epidural space. The dura mater was attached anteriorly to the posterior longitudinal ligament (PLL). The PLL was attached to the vertebral body beside the midline, whereas it adhered to the posterior edge of intervertebral disc. The anterior internal vertebral venous plexus was located anterolaterally and anteromedially. The vertebral canal was lined with connective tissue that differentiated in a periosteum in contact with the ossification centers. At 15 weeks, the PLL was composed of deep and superficial layers. At 21 weeks, the attachment between the dura mater and PLL was ligament-like at the level of the vertebral body. At 32 weeks, the dura mater was adherent to the superficial layer of PLL. At 39 weeks, groups of adipocytes were identified, and the dura mater was attached to the PLL by some ligaments. There were many more similarities between the adult and the 39-week fetus. In conclusion, some differences in the anatomy of the epidural space exist at each fetal stage studied. The structures of the epidural space are already formed in the fetus of 13 weeks, but they differentiate progressively within the connective tissue.

Dura Mater↗
PubMed2002

[Microscopic vascular study of the colon with the corrosion casting technique].

The aim of this study is, firstly, to assess the accuracy of vascular casts obtained at various times after death and secondly to describe the mucosal microvascular architecture of the cat colon. Two injections were realized, the first one on a non-embalmed human corpse, 12 days after the death, and the other one on a cat, immediately following euthanasia. Results show that this second cast seems finer and more detailed than the cast stemming from the human corpse; indeed, the finest vessels obtained are about 6 microns while they are about 15 microns on the human corpse. This could be explained by a post-mortem obstruction of microvessels, that prevented the passage of the injected product or by an insufficient amount of product injected. Finally, the vascular cast of the cat colic mucosa presents a regular honeycomb-like network that bounds the colonic mucosal glands, a finding consistent with the results reported previously.

Aged↗
PubMed2001

The origin of the azygos venous system, as deduced from an anatomical and radiological study employing a corrosion technique.

The aim of this study is not only to describe the origin of the human azygos venous system by performing a 3-D reconstruction of a CT scan but also to evaluate the value of the techniques employed in investigating the topographical anatomy of a venous system in the body. Following perfusion with saline to wash away the blood, we injected an ALTUFIX/MINIUM mixture into the azygos vein of a cadaver. The head and trunk were subsequently corroded with hydrochloric acid (HCl). A CT scan of the trunk was obtained both before and after corrosion. According to the spatial resolution of the CT scan, the thinnest identifiable detail was measurable as 0.5 mm. The vertebral lumbar venous system was described, specifying the nomenclature of the lumbar veins (the lumbar veins being designated according to the vertebral body along which they run). On the right side, the lumbar veins at L2 and at L3 formed the lateral root of the azygos vein. On the left side, the vein at L2 formed the reno-azygo-lumbar arch (of Lejars). The lumbar veins, and the origin of the azygos system, were described and compared with previous studies. The 3-D reconstruction showed the importance of veins associated with the posterior paravertebral muscles. This description poses the problem of the metamerisation of the veins, but further evidence is required. Comparisons of the CT scans, 3-D reconstructions, and the ALTUFIX models of the veins obtained from the corrosion technique allowed verification of the 3-D reconstruction and correction of the errors inherent in a computer reconstruction. It is concluded that the description, and understanding, of such a complex system as the vertebral venous system is more valid when the results obtained using different techniques are compared.

Aged↗
PubMed1999

[The lumbar vein at L2 and the reno-azygo-lumbar arch: anatomic and radiologic studies].

The lumbar vein at L2 was described by C. Gillot and B. Singer (1974). On the right side, after drawing off the 12th intercostal vein, it forms the lateral root of the azygos vein. Its way is as a frame, transverse going along the body of the 2nd lumbar vertebra, then upward along the spine after having integrated the veins of the L2-L3 intervertebral foramen. In its typical form, the vein is at L2 but it can be at L1 or L3. It takes the name of lateral root of the azygos vein only after receiving the 12th intercostal vein. Because of its diameter (5 mm), it forms a cavo-caval anastomosis via the azygos vein. The renal azygo-lumbar arch of Lejars is the equivalent on the left side of the right vein at L2. This arch contributes to the formation of the lateral root of the hemi-azygos vein. The right vein at L2 and the reno-azygo-lumbar arch were studied by dissections and by radiologic protocols. The radiologic studies (CT, MRI, 3D reconstructions) were carried out after injections of gelatin-gadolinium-minimum and altufix-minimum mixtures. The results showed the numerous variations of origin of the azygos system. The use of multiple and complementary technics are very helpful to describe these variations.

Azygos Vein↗
PubMed1998

Technique for injection of the lumbar vertebral venous plexuses employed in anatomic, computed tomography and magnetic resonance imaging studies.

The aim of this study was to develop a technique for injection of the vertebral venous plexuses allowing anatomic, computed tomography (CT) and magnetic resonance imaging (MRI) studies of the same anatomic specimen. It proved in practice that only a correctly adjusted mixture of different agents allowed attainment of this objective. This mixture, composed of gelatin, gadolinium and minium, enabled us to attain this end. The description of the technique of injecting the vertebral venous plexuses, the difficulties encountered and the results of the different imaging techniques are analysed in this study without entering into details of the anatomic description. The core of the study consists of 11 unembalmed subjects. Three were injected with gelatin mixed with gadolinium, one with latex mixed with minium, one with latex mixed with gadolinium, and 6 with gelatin mixed with both gadolinium and minium. Only the mixture of gelatin-gadolinium-minium allowed study of the same anatomic specimen in terms of anatomy, CT and MRI. Two different MRI sequences are described, evidence of the different properties of the injection mixture (gelatin, gadolinium). The latex-minium mixture gave good CT density but was unsuitable for MRI studies. Numerous artifacts caused interference with the radiologic images, calling for perfect injection technique. The use of several radiologic techniques for a single cadaveric injection allows better correlation of the images, and comparison and verification of results between the techniques.

Adult↗
PubMed1996

The lumbar anterior epidural cavity: the posterior longitudinal ligament, the anterior ligaments of the dura mater and the anterior internal vertebral venous plexus.

The contents of the anterior epidural cavity were studied to elucidate the relationship between veins, ligaments, and membranous formations. Anatomical, radiological and histological studies on human specimens after latex or gelatin/gadolinium venous injection at the level of the lumbar spine show that the posterior longitudinal ligament is a cross-shaped formation which includes the septum, the superficial part extending into the intervertebral foramen and the anterior ligaments of the dura mater. The anterior epidural cavity contains two medial and two lateral spaces. The two medial cavities enclose anterior and medial venous plexuses, which together receive the basivertebral veins; the two lateral cavities receive the anterior longitudinal veins. Contents of the medial and lateral cavities pass freely between the two. The lateral cavity connects with the intervertebral canal and dorsally into the posterior epidural space.

Dissection↗
PubMed1994

MRI of the epidural space after gelatin/gadolinium venous injection.

The head and vertebral column from two human cadavers were injected with a solution of gelatin and gadolinium (Dotarem) and imaged using magnetic resonance imaging (MRI). Comparisons between gross anatomic slices and corresponding images of the lumbar vertebral column confirmed the usefulness of a paramagnetic agent for visualising the epidural venous plexus. This technique provides accurate images of the posterior longitudinal ligament.

Contrast Media↗
PubMed1988

[Fever caused by metapramine. Diagnosis of fever caused by psychotropic drugs].

Because of two hyperthermias, due to metapramine a french antidepressives of the tricyclic family, international literature concerning drug fever induced by psychotropics was reviewed. This study stresses the fact that apart from neuroleptics which are frequently involved in that type of accident, other psychotropics are very rarely responsible of hyperthermia. One hundred and five cases published since 1970 and sufficiently well documented to be analysed according to Dangoumeau's french method of imputation of side effects of drugs, were reviewed. Among these cases, one hundred (95%) corresponded to malignant syndrome of neuroleptics, 89 concerned neuroleptics alone, and 11, neuroleptics associated with other psychotropics. Regarding the different mechanisms which can explain drug fever as described by Lipsky, it seems that concerning psychotropics two types may be retained: Fever due to central dysregulation directly induced by drugs, and mainly, immunoallergic fever, the most frequently seen as described in our two cases.

Aged↗