De la neutralité du personnel sanitaire au cours des hostilités

La guerre de Crimée (1854-1856) révéla l'insuffisance presque complète des Services de santé militaires des nations belligérantes qui, après plusieurs années de paix, engagèrent les hostilités sans préparation ni organisation sanitaire suffisantes. La cause profonde de cette carence résidait dans le fait que le Service de santé des armées relevait de l'administration militaire, seule autorisée à disposer de l'équipement sanitaire et qui restreignait l'activité même des médecins militaires au domaine de la pratique médicale. L'échec complet de cette organisation fut à l'origine de l'autonomie et de l'indépendance accordées ultérieurement au Service de santé des armées de la majorité des pays européen

Synchrotron radiation in radiology: novel X-ray sources

X-rays, the key ingredient of radiology, are still primarily produced with the mechanism discovered by Röntgen over one century ago. A different approach, however, is becoming increasingly important: the use of synchrotron sources based on fast-moving electrons and on their relativistic properties. We discuss the elements of this new strategy, its practical implementation, and some new types of synchrotron sources under development. The present and potential impact on radiology of different classes of synchrotron sources is briefly and realistically analyze

Fluctuation Patterns of Autonomic Arousal Predict Mental Arithmetic Performance

Pupil dilation, an autonomic arousal response, can measure attention because pupil dilation positively correlates with attention. This study investigated the predictability of mental arithmetic performance from pupil dilation fluctuation patterns of 11 college students. Arithmetic problems consisted of basic addition and varied in difficulty. The mental arithmetic task was administered while recording pupil dilation at 60 Hz with an ISCAN eye tracker. A pupil diameter baseline was measured before problems. Patterns of pupil diameter change from the baseline over time were analyzed by difficulty and performance. A marginal effect of Difficulty, marginal effect of Performance, and significant effect of Time on Pupil Dilation change were observed. Both Time by Difficulty and Time by Performance interacted significantly. However, Difficulty and Performance did not interact. These findings support the conclusion that attention increased over time during mental arithmetic problems. Furthermore, attention over time increased more on difficult problems and on correct problems

"Trooping the color”: restoring the original donor skin color by addition of melanocytes to bioengineered skin analogs

Purpose: Autologous skin substitutes to cover large skin defects are used since several years. Melanocytes, although essential for solar protection and pigmentation of skin, are not yet systematically added to such substitutes. In this experimental study, we reconstructed melanocyte-containing dermo-epidermal skin substitutes from donor skins of different skin pigmentation types and studied them in an animal model. Features pertinent to skin color were analyzed and compared in both skin substitutes and original donor skin. Methods: Keratinocytes, melanocytes, and fibroblast were isolated, cultured, and expanded from skin biopsies of light- and dark-pigmented patients. For each donor, melanocytes and keratinocytes were seeded in different ratios (1:1, 1:5, 1:10) onto collagen gels previously populated with autologous fibroblasts. Skin substitutes were then transplanted onto full-thickness wounds of immuno-incompetent rats. After 8weeks, macroscopic and microscopic analyses were conducted with regard to skin color and architecture. Results: Chromameter evaluation revealed that skin color of reconstructed light- and dark-pigmented skin was very similar to donor skin, independent of which melanocyte/keratinocyte ratio was added. Histological analyses of the skin analogs confirmed these findings. Conclusion: These data suggest that adding autologous melanocytes to bioengineered dermo-epidermal skin analogs can sustainably restore the patients' native skin colo

Spontaneous bilateral subdural haematomas in the posterior cranial fossa revealed by MRI

A 52-year-old woman treated for acute myeloproliferative disease developed progressive stupor. CT showed obstructive hydrocephalus resulting from unexplained mass effect on the fourth ventricle. MRI revealed bilateral extra-axial collections in the posterior cranial fossa, giving high signal on T1- and T2-weighted images, suggesting subacute subdural haematomas. Subdural haematomas can be suspected on CT when there is unexplained mass effect. MRI may be essential to confirm the diagnosis and plan appropriate treatmen

Rebuild, restore, reinnervate: do human tissue engineered dermo-epidermal skin analogs attract host nerve fibers for innervation?

Purpose: Tissue engineered skin substitutes are a promising tool to cover large skin defects, but little is known about reinnervation of transplants. In this experimental study, we analyzed the ingrowth of host peripheral nerve fibers into human tissue engineered dermo-epidermal skin substitutes in a rat model. Using varying cell types in the epidermal compartment, we wanted to assess the influence of epidermal cell types on reinnervation of the substitute. Methods: We isolated keratinocytes, melanocytes, fibroblasts, and eccrine sweat gland cells from human skin biopsies. After expansion, epidermal cells were seeded on human dermal fibroblast-containing collagen type I hydrogels as follows: (1) keratinocytes only, (2) keratinocytes with melanocytes, (3) sweat gland cells. These substitutes were transplanted into full-thickness skin wounds on the back of immuno-incompetent rats and were analyzed after 3 and 8weeks. Histological sections were examined with regard to myelinated and unmyelinated nerve fiber ingrowth using markers such as PGP9.5, NF-200, and NF-145. Results: After 3weeks, the skin substitutes of all three epidermal cell variants showed no neuronal ingrowth from the host into the transplant. After 8weeks, we could detect an innervation of all three types of skin substitutes. However, the nerve fibers were restricted to the dermal compartment and we could not find any unmyelinated fibers in the epidermis. Furthermore, there was no distinct difference between the constructs resulting from the different cell types used to generate an epidermis. Conclusion: Our human tissue engineered dermo-epidermal skin substitutes demonstrate a host-derived innervation of the dermal compartment as early as 8weeks after transplantation. Thus, our substitutes apparently have the capacity to attract nerve fibers from adjacent host tissues, which also grow into grafts and thereby potentially restore skin sensitivit