Management of a post-operative multi-resistant infectious spondylitis associated with a kyphotic deformity.

Anterior spinal infection (prevertebral abscess and/or discitis) after posterior instrumentation for vertebral fractures is a challenging complication, since a new implant may become necessary anteriorly, in a septic environment. Generally accepted management guidelines are yet to be established. The authors present a case of posterior instrumentation for fractures of T12 and L1, complicated after 9 months with an anterior infection (prevertebral abscess and discitis) with extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli). This case is unique in that the multi-resistant organism was isolated only after the second stage of infection treatment, which consisted of anterior débridement and anterior implantation of titanium cages and rods. In this particular case, infection was controlled despite implantation of multiple cages, screws and rods, and fusion was achieved, by means of intravenous antibiotic treatment for 12 months. At the latest follow-up, 24 months post surgery, there was no evidence of infection. This problem case may be helpful for surgeons confronted with spinal deformities secondary to infections with multi-resistant organisms.

Actualiser le passé : figures antiques du Moyen Âge à la Renaissance

Résumé : En littérature comme dans les arts figuratifs, voire dans la réalité vécue, l'Antiquité se révèle avoir une proximité plus ou moins grande selon les périodes et les auteurs, mais elle a toujours été présente, toujours féconde. La frontière poreuse entre l'ancien et le moderne fait de l'Antiquité et du Moyen Âge, puis de l'Antiquité et de l'early modern des vases communicants. C'est là une conviction aujourd'hui largement partagée et plusieurs manifestations récentes ont eu pour objet cet aspect-clé de la culture occidentale. Les contributions réunies dans les présents Actes sont le fruit d'un colloque interdisciplinaire de deux jours (13 et 14 mai 2011) organisé par le Centre d'Études Médiévales et Post-Médiévales (CEMEP) de l'Université de Lausanne ; elles ont, chacune, apporté leur pierre à une réflexion en marche en portant des regards croisés sur les formes d'actualisation que connaissent - entre continuités et discontinuités - les figures antiques du Moyen Âge à la Renaissance. Le volume s'articule en trois parties, dans lesquelles le lecteur trouvera des contributions dues à la plume de spécialistes de l'histoire, de l'histoire de l'art et de la littérature : I. Réécritures : entre éthique et esthétique II. Translations politiques III. Actualisation : du Moyen Âge à la modernité

In Vivo Modulation of Mitochondrial Activity Determines HSC Engraftment and Post-Transplant Survival in Mice

Cellular metabolism is emerging as a potential fate determinant in cancer and stem cell biology, constituting a crucial regulator of the hematopoietic stem cell (HSC) pool [1-4]. The extremely low oxygen tension in the HSC microenvironment of the adult bone marrow forces HSCs into a low metabolic profile that is thought to enable their maintenance by protecting them from reactive oxygen species (ROS). Although HSC quiescence has for long been associated with low mitochondrial activity, as testified by the low rhodamine stain that marks primitive HSCs, we hypothesized that mitochondrial activation could be an HSC fate determinant in its own right. We thus set to investigate the implications of pharmacologically modulating mitochondrial activity during bone marrow transplantation, and have found that forcing mitochondrial activation in the post-transplant period dramatically increases survival. Specifically, we examined the mitochondrial content and activation profile of each murine hematopoietic stem and progenitor compartment. Long-term-HSCs (LT-HSC, Lin-cKit+Sca1+ (LKS) CD150+CD34-), short-term-HSCs (ST-HSC, LKS+150+34+), multipotent progenitors (MPPs, LKS+150-) and committed progenitors (PROG, Lin-cKit+Sca1-) display distinct mitochondrial profiles, with both mitochondrial content and activity increasing with differentiation. Indeed, we found that overall function of the hematopoietic progenitor and stem cell compartment can be resolved by mitochondrial activity alone, as illustrated by the fact that low mitochondrial activity LKS cells (TMRM low) can provide efficient long-term engraftment, while high mitochondrial activity LKS cells (TMRM high) cannot engraft in lethally irradiated mice. Moreover, low mitochondrial activity can equally predict efficiency of engraftment within the LT-HSC and ST-HSC compartments, opening the field to a novel method of discriminating a population of transitioning ST-HSCs that retain long-term engraftment capacity. Based on previous experience that a high-fat bone marrow microenvironment depletes short-term hematopoietic progenitors while conserving their long-term counterparts [5], we set to measure HSC mitochondrial activation in high-fat diet fed mice, known to decrease metabolic rate on a per cell basis through excess insulin/IGF-1 production. Congruently, we found lower mitochondrial activation as assessed by flow cytometry and RT-PCR analysis as well as a depletion of the short-term progenitor compartment in high fat versus control chow diet fed mice. We then tested the effects of a mitochondrial activator known to counteract the negative effects of high fat diet. We first analyzed the in vitro effect on HSC cell cycle kinetics, where no significant change in proliferation or division time was found. However, HSCs responded to the mitochondrial activator by increasing asynchrony, a behavior that is thought to directly correlate with asymmetric division [6]. As opposed to high-fat diet fed mice, mice fed with the mitochondrial activator showed an increase in ST-HSCs, while all the other hematopoietic compartments were comparable to mice fed on control diet. Given the dependency on short-term progenitors to rapidly reconstitute hematopoiesis following bone marrow transplantation, we tested the effect of pharmacological mitochondrial activation on the recovery of mice transplanted with a limiting HSC dose. Survival 3 weeks post-transplant was 80% in the treated group compared to 0% in the control group, as predicted by faster recovery of platelet and neutrophil counts. In conclusion, we have found that mitochondrial activation regulates the long-term to short-term HSC transition, unraveling mitochondrial modulation as a valuable drug target for post-transplant therapy. Identification of molecular pathways accountable for the metabolically mediated fate switch is currently ongoing.

L'Écriture à rebours. Le Roman de Méliadus du XIIIe au XVIIIe siècle

Continuation elleptique du "Tristan en prose", qui s'inscrit dans l'interstice séparant la naissance de Tristan du remariage de Méliadus avec la fille du roi Hoël, le "Roman de Meliadus" (1235-1240) est une oeuvre demeurée ouverte, de par son inachèvement et de par le dialogue constant qu'il instaure avec les autres romans arthuriens. S'il revendique sa filiation et assume son statut de récit puîné, les réminiscences qu'il exhibe masquent aussi les gauchissements, les infléchissements qui lui permettent de faire du neuf avec du vieux. C'est ce jeu - aux deux sens du terme - que Barbara Wahlen étudie et montre à voir, non seulement dans le "Roman de Meliadus" proprement dit, mais également dans trois de ses relectures, qui actualisent et renouvellent la signification du roman en profondeur. La première est une continuation de la toute fin du XIIIe ou du début du XIVe siècle qui est aujourd'hui conservée par le seul manuscrit Ferrell 5. La deuxième actualisation retenue est celle qu'offre "Meliadus de Leonnoys", l'imprimé publié en 1528 par Galliot du Pré, fruit d'un minutieux travail de découpage et de remontage. La dernière enfin est l'extrait paru en 1776 dans la "Bibliothèque Universelle des Romans".

Self-reported health needs and use of primary health care services by adolescents enrolled in post-mandatory schools or vocational training programmes in Switzerland.

BACKGROUND: The second Swiss Multicenter Adolescent Survey on Health (SMASH02) was conducted among a representative sample (n = 7428) of students and apprentices aged 16 to 20 from the three language areas of Switzerland during the year 2002. This paper reports on health needs expressed by adolescents and their use of health care services over the 12 months preceding the survey. METHODS: Nineteen cantons representing 80% of the resident population agreed to participate. A complex iterative random cluster sample of 600 classes was drawn with classes as primary sampling unit. The participation rate was 97.7% for the classes and 99.8% for the youths in attendance. The self-administered questionnaire included 565 items. The median rate of item non-response was 1.8%. Ethical and legal requirements applying to surveys of adolescent populations were respected. RESULTS: Overall more than 90% of adolescents felt in good to excellent health. Suffering often or very often from different physical complaints or pain was also reported such as headache (boys: 15.9%, girls: 37.4%), stomach-ache (boys: 9.7%, girls: 30.0%), joint pain (boys: 24.7%, girls: 29.5%) or back pain (boys: 24.3%, girls: 34.7%). Many adolescents reported a need for help on psychosocial and lifestyle issues, such as stress (boys: 28.5%, girls: 47.7%) or depression (boys: 18.9%, girls: 34.4%). Although about 75% of adolescents reported having consulted a general practitioner and about one-third having seen another specialist, reported reasons for visits do not correspond to the expressed needs. Less than 10% of adolescents had visited a psychiatrist, a family planning centre or a social worker. CONCLUSIONS: The reported rates of health services utilisation by adolescents does not match the substantial reported needs for help in various areas. This may indicate that the corresponding problems are not adequately detected and/or addressed by professionals from the health and social sectors.