Predicting the mating system from phenotypic correlations between life-history and sperm quality traits in the Alpine whitefish Coregonus zugensis

The mating behavior and reproductive strategies of Alpine whitefish like Coregonus zugensis (Nusslin) are poorly understood, probably because they spawn in deep water where direct observations are difficult. In this study, we interpret life-history and sperm quality traits of fish that we caught from their spawning place. We found that males invest heavily into gonadal tissue (up to 5.6% of their body weight), which is, in comparison to other fish, consistent with external fertilization, distinct pairing and moderate to high communal spawning, or no pairing and low to moderate communal spawning. Sperm competition theory and recent experimental studies on other salmonids predict that males optimize ejaculate characteristics in relation to the costs of sperm and the level of competition they have to expect: dominant males are predicted to invest less into ejaculate quality and to have slower spermatozoa than subdominant males. We found that spermatozoa of older males are slower than those of younger males. Moreover, older males have larger breeding tubercles, a secondary sexual trait that has, in some previous studies, been found to be linked to good condition and to good genetic quality. Our results suggest that C. zugensis has age-linked reproductive strategies, that multimale spawning is common, i.e., that sperm competition plays a significant role, and that older males are on average dominant over younger males at the spawning place.

Electrophoretic mobility of supercoiled, catenated and knotted DNA molecules.

We systematically varied conditions of two-dimensional (2D) agarose gel electrophoresis to optimize separation of DNA topoisomers that differ either by the extent of knotting, the extent of catenation or the extent of supercoiling. To this aim we compared electrophoretic behavior of three different families of DNA topoisomers: (i) supercoiled DNA molecules, where supercoiling covered the range extending from covalently closed relaxed up to naturally supercoiled DNA molecules; (ii) postreplicative catenanes with catenation number increasing from 1 to ∼15, where both catenated rings were nicked; (iii) knotted but nicked DNA molecules with a naturally arising spectrum of knots. For better comparison, we studied topoisomer families where each member had the same total molecular mass. For knotted and supercoiled molecules, we analyzed dimeric plasmids whereas catenanes were composed of monomeric forms of the same plasmid. We observed that catenated, knotted and supercoiled families of topoisomers showed different reactions to changes of agarose concentration and voltage during electrophoresis. These differences permitted us to optimize conditions for their separation and shed light on physical characteristics of these different types of DNA topoisomers during electrophoresis.

Nutrigenomics and nutrigenetics: the emerging faces of nutrition.

The recognition that nutrients have the ability to interact and modulate molecular mechanisms underlying an organism's physiological functions has prompted a revolution in the field of nutrition. Performing population-scaled epidemiological studies in the absence of genetic knowledge may result in erroneous scientific conclusions and misinformed nutritional recommendations. To circumvent such issues and more comprehensively probe the relationship between genes and diet, the field of nutrition has begun to capitalize on both the technologies and supporting analytical software brought forth in the post-genomic era. The creation of nutrigenomics and nutrigenetics, two fields with distinct approaches to elucidate the interaction between diet and genes but with a common ultimate goal to optimize health through the personalization of diet, provide powerful approaches to unravel the complex relationship between nutritional molecules, genetic polymorphisms, and the biological system as a whole. Reluctance to embrace these new fields exists primarily due to the fear that producing overwhelming quantities of biological data within the confines of a single study will submerge the original query; however, the current review aims to position nutrigenomics and nutrigenetics as the emerging faces of nutrition that, when considered with more classical approaches, will provide the necessary stepping stones to achieve the ambitious goal of optimizing an individual's health via nutritional intervention.

Tissue homing and persistence of defined antigen-specific CD8+ tumor-reactive T-cell clones in long-term melanoma survivors.

Tumor antigen-specific cytotoxic T cells (CTLs) play a major role in the adaptive immune response to cancers. This CTL response is often insufficient because of functional impairment, tumor escape mechanisms, or inhibitory tumor microenvironment. However, little is known about the fate of given tumor-specific CTL clones in cancer patients. Studies in patients with favorable outcomes may be very informative. In this longitudinal study, we tracked, quantified, and characterized functionally defined antigen-specific T-cell clones ex vivo, in peripheral blood and at tumor sites, in two long-term melanoma survivors. MAGE-A10-specific CD8+ T-cell clones with high avidity to antigenic peptide and tumor lytic capabilities persisted in peripheral blood over more than 10 years, with quantitative variations correlating with the clinical course. These clones were also found in emerging metastases, and, in one patient, circulating clonal T cells displayed a fully differentiated effector phenotype at the time of relapse. Longevity, tumor homing, differentiation phenotype, and quantitative adaptation to the disease phases suggest the contribution of the tracked tumor-reactive clones in the tumor control of these long-term metastatic survivor patients. Focusing research on patients with favorable outcomes may help to identify parameters that are crucial for an efficient antitumor response and to optimize cancer immunotherapy.

Pharmacokinetic and pharmacodynamic assessment of valganciclovir in solid organ transplant recipients

RESUME : Valganciclovir (Valcyte®) is an orally administered ester prodrug of the standard anticytomegalovirus (CMV) drug ganciclovir. This drug enabled an important reduction of the burden of CMV morbidity and mortality in solid organ transplant recipients. Prevention of CMV infection and treatment of CMV disease requires drug administration during many weeks. Oral drug administration is therefore convenient. Valganciclovir has been developed to overcome the poor oral availability of ganciclovir, which limits its concentration exposure after oral administration and thus its efficacy. This prodrug crosses efficiently the intestinal barrier, is then hydrolyzed into ganciclovir, providing exposure similar to intravenous ganciclovir. Valganciclovir is now preferred for the prophylaxis and treatment of CMV infection in solid organ transplant recipients. Nevertheless, adequate dosage adjustment is necessary to optimize its use, avoiding either insufficient or exaggerate exposure related to differences in its pharmacokinetic profile between patients. The main goal of this thesis was to better describe the pharmacokinetic and pharmacodynamic profile of valganciclovir in solid organ transplant recipients, to assess their reproducibility and their predictability, and thus to evaluate the current recommendations for valganciclovir dosage adjustment and the potential contribution of routine therapeutic drug monitoring (TDM) to patients' management. A total of 437 ganciclovir plasma concentration data from 65 transplant patients (41 kidney, 12 lung, 10 heart and 2 liver recipients, 58 under oral valganciclovir prophylaxis, 8 under oral valganciclovir treatment and 2 under intravenous ganciclovir) were measured using a validated chromatographic method (HPLC) developed for this study. The results were analyzed by non-linear mixed effect modeling (NONMEM). A two-compartment model with first-order absorption appropriately described the data. Systemic clearance was markedly influenced by GFR, with further differences between graft types and sex (CL/GFR = 1.7 in kidney, 0.9 in heart and 1.2 in lung and liver recipients) with interpatient variability (CV%) of 26% and interoccasion variability of 12%. Body weight and sex influenced central volume of distribution (V1 = 0.34 l/kg in males and 0.27 l/kg in females) with an interpatient variability of 20%. Residual intrapatient variability was 21 %. No significant drug interaction influenced GCV disposition. VGC prophylactic efficacy and tolerability were good, without detectable dependence on GCV profile. In conclusion, this analysis highlights the importance of thorough adjustment of VGC dosage to renal function and body weight. Considering the good predictability and reproducibility of GCV profile after oral VGC in solid organ transplant recipients, routine TDM does not appear to be clinically indicated. However, GCV plasma measurement may still be helpful in specific clinical situations such as documentation of appropriate exposure in patients with potentially compromised absorption, or lack of response to CMV disease treatment, or under renal replacement therapy. RESUME : Le valganciclovir (Valcyte®) est un promédicament oral du ganciclovir qui est un anti-infectieux de référence contre les infections à cytomegalovirus (CMV). Cet antiviral a permis de réduire les effets délétères de cette infection jusqu'ici responsable d'une importante morbidité et mortalité chez les transplantés d'organe. La prévention et le traitement de l'infection à CMV sont donc nécessaires mais requièrent l'administration d'un agent antiviral sur une longue période. Un médicament administré par voie orale représente donc un avantage évident. Le valganciclovir a été développé dans le but d'améliorer la faible absorption orale du ganciclovir, et donc son efficacité. Cet ester valylique du ganciclovir traverse plus facilement la barrière gastro-intestinale, puis est hydrolysé en ganciclovir dans la circulation sanguine, produisant une exposition comparable à celle d'une perfusion intraveineuse de ganciclovir. De ce fait, le valganciclovir est devenu largement utilisé pour la prophylaxie mais aussi le traitement de l'infection à CMV. Néanmoins une utilisation optimale de ce nouveau médicament nécessite de bonnes connaissances sur son profil pharmacocinétique afin d'établir un schéma de dose adapté pour éviter tant une surexposition qu'une sous-exposition résultant des différences d'élimination entre les patients. Le but de cette thèse a été d'étudier le profil pharmacocinétique et pharmacodynamique du valganciclovir chez les transplantés d'organe ainsi que sa reproductibilité et sa prédictibilité. Il s'agissait d'apprécier de manière critique le schéma actuellement recommandé pour l'adaptation des doses de valganciclovir, mais aussi la contribution éventuelle d'un suivi des concentrations sanguines en routine. Un total de 437 taux sanguins de ganciclovir ont été mesurés, provenant de 65 patients transplantés d'organe (41 rénaux, 12 pulmonaires, 10 cardiaques et 2 hépatiques, 58 sous une prophylaxie orale de valganciclovir, 8 sous un traitement de valganciclovir et 2 sous un traitement intraveineux). Une méthode de chromatographie liquide à haute performance a été développée et validée pour cette étude. Les résultats ont été ensuite analysés par modélisation non linéaire à effets mixtes (NONMEM). Un modèle à deux compartiments avec absorption de premier ordre a permis de décrire les données. La clairance systémique était principalement influencée par le débit de filtration glomérulaire (GFR), avec une différence entre les types de greffe et les sexes (CL/GFR = 1.7 chez les greffés rénaux, 0.9 pour les greffés cardiaques et 1.2 pour le groupe des greffés pulmonaires et hépatiques) avec un variabilité inter-individuelle de 26% (CV%) et une variabilité inter-occasion de 12%. Le poids corporel ainsi que le sexe avaient une influence sur le volume central de distribution (V1 = 0.34 l/kg chez les hommes et 0.27 l/kg chez les femmes) avec une variabilité inter-individuelle de 20%. La variabilité intra-individuelle résiduelle était de 21 %. Aucune interaction médicamenteuse n'a montré d'influence sur le profil du ganciclovir. La prophylaxie avec le valganciclovir s'est révélée efficace et bien tolérée. En conclusion, cette analyse souligne l'importance d'une adaptation de la dose du valganciclovir à la fonction rénale et au poids du patient. Au vu de la bonne reproductibilité et prédictibilité du profil pharmacocinétique du ganciclovir chez les patients transplantés recevant du valganciclovir, un suivi des concentrations sanguines en routine ne semble pas cliniquement indiqué. Néanmoins, la mesure des taux plasmatiques de ganciclovir peut être utile dans certaines situations particulières, comme la vérification d'une exposition appropriée chez des patients susceptibles d'absorption insuffisante, ou ne répondant pas au traitement d'une infection à CMV ou encore sous épuration extra-rénale. RESUME LARGE PUBLIC : Le valganciclovir est un précurseur capable de libérer du ganciclovir, récemment développé pour améliorer la faible absorption orale de ce dernier. Une fois le valganciclovir absorbé, le ganciclovir libéré dans la circulation sanguine devient efficace contre les infections à cytomégalovirus. Ce virus largement répandu est responsable de maladies insidieuses et parfois graves chez les personnes présentant une baisse des défenses immunitaires, comme les greffés d'organe recevant un traitement anti-rejet. Le ganciclovir est administré pendant plusieurs mois consécutifs soit pour prévenir une infection après la transplantation, soit pour traiter une infection déclarée. La facilité d'administration du valganciclovir par voie orale représente un avantage sur une administration du ganciclovir par perfusion, qui nécessite une hospitalisation. Toutefois, la voie orale peut être une source supplémentaire de variabilité chez les patients, avec un impact potentiel sur l'efficacité ou la toxicité du médicament. Le but de cette étude a été - de décrire le devenir de ce médicament dans le corps humain (dont l'étude relève de la discipline de la pharmacocinétique) - de définir les facteurs cliniques pouvant expliquer les différences de concentration sanguine observées entre les patients sous une posologie donnée - d'explorer les relations entre les concentrations du médicament dans le sang et son efficacité ou la survenue d'effets indésirables (dont l'étude relève de la discipline de la pharmacodynamie). Cette étude a nécessité le développement et la validation, d'une méthode d'analyse pour mesurer la concentration sanguine du ganciclovir, puis son application à 437 échantillons provenant de 65 patients transplantés d'organe solide (41 rénaux, 12 pulmonaires, 10 cardiaques et 2 hépatiques) recevant du valganciclovir. Les résultats des mesures effectuées ont été analysés à l'aide d'un outil mathématique afin d'élaborer un modèle du devenir du médicament dans le sang chez chaque patient et à chaque occasion. Cette étude a permis d'évaluer chez des patients recevant le valganciclovir, la vitesse à laquelle l'organisme absorbe, distribue, puis élimine le médicament. La vitesse d'élimination dépendait étroitement de la fonction rénale, du type de greffe et du sexe alors que la distribution dépendait du poids et du sexe du patient. La variabilité non expliquée par ces facteurs cliniques était modérée et vraisemblablement sans conséquence clinique évidente soit sur l'efficacité ou la tolérance, qui se révèlent très satisfaisantes chez les patients de l'étude. Les observations n'ont pas révélé de relation entre les concentrations de médicament et l'efficacité thérapeutique ou la survenue d'effets indésirables, confirmant que les doses relativement faibles utilisées dans notre collectif de patients suffisaient à produire une exposition reproductible à des concentrations adéquates. En conclusion, le profil (et par conséquent l'absorption) du valganciclovir chez les patients transplantés semble bien prédictible après une adaptation de la dose à la fonction rénale et au poids du patient. Un contrôle systématique des concentrations sanguines n'est probablement pas indiqué en routine, mais cette mesure peut présenter un intérêt dans certaines conditions particulières.

Affections pulmonaires et attitude [High altitude and preexisting lung diseases].

Today, a growing number of people, some of them suffering from lung diseases, travel to high altitude resorts. It is sometimes not easy for the general practitioner to adequately counsel these patients. Based on our knowledge of physiopathology and clinical studies, the present paper addresses the effects of high altitude in patients with preexisting lung diseases and provides recommendations in order to optimize the sojourn at high altitude.

Towards a diffusion image processing validation and accuracy prediction framework

Validation is the main bottleneck preventing theadoption of many medical image processing algorithms inthe clinical practice. In the classical approach,a-posteriori analysis is performed based on someobjective metrics. In this work, a different approachbased on Petri Nets (PN) is proposed. The basic ideaconsists in predicting the accuracy that will result froma given processing based on the characterization of thesources of inaccuracy of the system. Here we propose aproof of concept in the scenario of a diffusion imaginganalysis pipeline. A PN is built after the detection ofthe possible sources of inaccuracy. By integrating thefirst qualitative insights based on the PN withquantitative measures, it is possible to optimize the PNitself, to predict the inaccuracy of the system in adifferent setting. Results show that the proposed modelprovides a good prediction performance and suggests theoptimal processing approach.

Co- and posttranslational modification of the alpha(1B)-adrenergic receptor: effects on receptor expression and function.

We have characterized the maturation, co- and posttranslational modifications, and functional properties of the alpha(1B)-adrenergic receptor (AR) expressed in different mammalian cells transfected using conventional approaches or the Semliki Forest virus system. We found that the alpha(1B)-AR undergoes N-linked glycosylation as demonstrated by its sensitivity to endoglycosidases and by the effect of tunicamycin on receptor maturation. Pulse-chase labeling experiments in BHK-21 cells demonstrate that the alpha(1B)-AR is synthesized as a 70 kDa core glycosylated precursor that is converted to the 90 kDa mature form of the receptor with a half-time of approximately 2 h. N-Linked glycosylation of the alpha(1B)-AR occurs at four asparagines on the N-terminus of the receptor. Mutations of the N-linked glycosylation sites did not have a significant effect on receptor function or expression. Surprisingly, receptor mutants lacking N-linked glycosylation migrated as heterogeneous bands in SDS-PAGE. Our findings demonstrate that N-linked glycosylation and phosphorylation, but not palmitoylation or O-linked glycosylation, contribute to the structural heterogeneity of the alpha(1B)-AR as it is observed in SDS-PAGE. The modifications found are similar in the different mammalian expression systems explored. Our findings indicate that the Semliki Forest virus system can provide large amounts of functional and fully glycosylated alpha(1B)-AR protein suitable for biochemical and structural studies. The results of this study contribute to elucidate the basic steps involved in the processing of G protein-coupled receptors as well as to optimize strategies for their overexpression.

Results and harmonization guidelines from two large-scale international Elispot proficiency panels conducted by the Cancer Vaccine Consortium (CVC/SVI).

The Cancer Vaccine Consortium of the Sabin Vaccine Institute (CVC/SVI) is conducting an ongoing large-scale immune monitoring harmonization program through its members and affiliated associations. This effort was brought to life as an external validation program by conducting an international Elispot proficiency panel with 36 laboratories in 2005, and was followed by a second panel with 29 participating laboratories in 2006 allowing for application of learnings from the first panel. Critical protocol choices, as well as standardization and validation practices among laboratories were assessed through detailed surveys. Although panel participants had to follow general guidelines in order to allow comparison of results, each laboratory was able to use its own protocols, materials and reagents. The second panel recorded an overall significantly improved performance, as measured by the ability to detect all predefined responses correctly. Protocol choices and laboratory practices, which can have a dramatic effect on the overall assay outcome, were identified and lead to the following recommendations: (A) Establish a laboratory SOP for Elispot testing procedures including (A1) a counting method for apoptotic cells for determining adequate cell dilution for plating, and (A2) overnight rest of cells prior to plating and incubation, (B) Use only pre-tested serum optimized for low background: high signal ratio, (C) Establish a laboratory SOP for plate reading including (C1) human auditing during the reading process and (C2) adequate adjustments for technical artifacts, and (D) Only allow trained personnel, which is certified per laboratory SOPs to conduct assays. Recommendations described under (A) were found to make a statistically significant difference in assay performance, while the remaining recommendations are based on practical experiences confirmed by the panel results, which could not be statistically tested. These results provide initial harmonization guidelines to optimize Elispot assay performance to the immunotherapy community. Further optimization is in process with ongoing panels.

Occupational and patient exposure as well as image quality for full spine examinations with the EOS imaging system.

PURPOSE: EOS (EOS imaging S.A, Paris, France) is an x-ray imaging system that uses slot-scanning technology in order to optimize the trade-off between image quality and dose. The goal of this study was to characterize the EOS system in terms of occupational exposure, organ doses to patients as well as image quality for full spine examinations. METHODS: Occupational exposure was determined by measuring the ambient dose equivalents in the radiological room during a standard full spine examination. The patient dosimetry was performed using anthropomorphic phantoms representing an adolescent and a five-year-old child. The organ doses were measured with thermoluminescent detectors and then used to calculate effective doses. Patient exposure with EOS was then compared to dose levels reported for conventional radiological systems. Image quality was assessed in terms of spatial resolution and different noise contributions to evaluate the detector's performances of the system. The spatial-frequency signal transfer efficiency of the imaging system was quantified by the detective quantum efficiency (DQE). RESULTS: The use of a protective apron when the medical staff or parents have to stand near to the cubicle in the radiological room is recommended. The estimated effective dose to patients undergoing a full spine examination with the EOS system was 290μSv for an adult and 200 μSv for a child. MTF and NPS are nonisotropic, with higher values in the scanning direction; they are in addition energy-dependent, but scanning speed independent. The system was shown to be quantum-limited, with a maximum DQE of 13%. The relevance of the DQE for slot-scanning system has been addressed. CONCLUSIONS: As a summary, the estimated effective dose was 290μSv for an adult; the image quality remains comparable to conventional systems.

Ultra-performance liquid chromatography mass spectrometry and sensitive bioassay methods for quantification of posaconazole plasma concentrations after oral dosing.

Posaconazole (POS) is a new antifungal agent for prevention and therapy of mycoses in immunocompromised patients. Variable POS pharmacokinetics after oral dosing may influence efficacy: a trough threshold of 0.5 ?g/ml has been recently proposed. Measurement of POS plasma concentrations by complex chromatographic techniques may thus contribute to optimize prevention and management of life-threatening infections. No microbiological analytical method is available. The objective of this study was to develop and validate a new simplified ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method and a sensitive bioassay for quantification of POS over the clinical plasma concentration range. The UPLC-MS/MS equipment consisted of a triple quadrupole mass spectrometer, an electrospray ionization (ESI) source, and a C(18) analytical column. The Candida albicans POS-hypersusceptible mutant (MIC of 0.002 ?g/ml) ?cdr1 ?cdr2 ?flu ?mdr1 ?can constructed by targeted deletion of multidrug efflux transporters and calcineurin genes was used for the bioassay. POS was extracted from plasma by protein precipitation with acetonitrile-methanol (75%/25%, vol/vol). Reproducible standard curves were obtained over the range 0.014 to 12 (UPLC-MS/MS) and 0.028 to 12 ?g/ml (bioassay). Intra- and interrun accuracy levels were 106% ± 2% and 103% ± 4% for UPLC-MS/MS and 102% ± 8% and 104% ± 1% for bioassay, respectively. The intra- and interrun coefficients of variation were 7% ± 4% and 7% ± 3% for UPLC-MS/MS and 5% ± 3% and 4% ± 2% for bioassay, respectively. An excellent correlation between POS plasma concentrations measured by UPLC-MS/MS and bioassay was found (concordance, 0.96). In 26 hemato-oncological patients receiving oral POS, 27/69 (39%) trough plasma concentrations were lower than 0.5 ?g/ml. The UPLC-MS/MS method and sensitive bioassay offer alternative tools for accurate and precise quantification of the plasma concentrations in patients receiving oral posaconazole.

TEP/TDM en radiothérapie : indications et perspectives [PET/CT and radiotherapy: indications and potential applications].

The implementation of new techniques of imaging in the daily practice of the radiation oncologist is a major advance in these last 10 years. This allows optimizing the therapeutic intervals and locoregional control of the disease while limiting side effects. Among them, positron emission tomography (PET) offers an opportunity to the clinician to obtain data relative to the tumoral biological mechanisms, while benefiting from the morphological images of the computed tomography (CT) scan. Recently hybrid PET/CT has been developed and numerous studies aimed at optimizing its use in the planning, the evaluation of the treatment response and the prognostic value. The choice of the radiotracer (according to the type of cancer and to the studied biological mechanism) and the various methods of tumoral delineation, require a regular update to optimize the practices. We propose throughout this article, an exhaustive review of the published researches (and in process of publication) until December 2011, as user guide of PET/CT in all the aspects of the modern radiotherapy (from the diagnosis to the follow-up): biopsy guiding, optimization of treatment planning and dosimetry, evaluation of tumor response and prognostic value, follow-up and early detection of recurrence versus tumoral necrosis. In a didactic purpose, each of these aspects is approached by primary tumoral location, and illustrated with representative iconographic examples. The current contribution of PET/CT and its perspectives of development are described to offer to the radiation oncologist a clear and up to date reading in this expanding domain.

Preventive and therapeutic strategies in critically ill patients with highly resistant bacteria.

The antibiotic pipeline continues to diminish and the majority of the public remains unaware of this critical situation. The cause of the decline of antibiotic development is multifactorial and currently most ICUs are confronted with the challenge of multidrug-resistant organisms. Antimicrobial multidrug resistance is expanding all over the world, with extreme and pandrug resistance being increasingly encountered, especially in healthcare-associated infections in large highly specialized hospitals. Antibiotic stewardship for critically ill patients translated into the implementation of specific guidelines, largely promoted by the Surviving Sepsis Campaign, targeted at education to optimize choice, dosage, and duration of antibiotics in order to improve outcomes and reduce the development of resistance. Inappropriate antimicrobial therapy, meaning the selection of an antibiotic to which the causative pathogen is resistant, is a consistent predictor of poor outcomes in septic patients. Therefore, pharmacokinetically/pharmacodynamically optimized dosing regimens should be given to all patients empirically and, once the pathogen and susceptibility are known, local stewardship practices may be employed on the basis of clinical response to redefine an appropriate regimen for the patient. This review will focus on the most severely ill patients, for whom substantial progress in organ support along with diagnostic and therapeutic strategies markedly increased the risk of nosocomial infections.

Aspects opératoires et péri-opératoires de la stimulation cérébrale profonde [Operative and perioperative aspects of deep brain stimulation].

La stimulation cérébrale profonde (SCP) nécessite l'implantation chirurgicale d'un système comprenant électrodes cérébrales et boîtier(s) de stimulation. Les noyaux cérébraux visés par la méthodologie stéréotaxique d'implantation doivent être visualisés au mieux par une imagerie à haute résolution. La procédure chirurgicale d'implantation des électrodes se fait si possible en anesthésie locale pour faire des mesures électro-physiologiques et tester en peropératoire l'effet de la stimulation, afin d'optimiser la position de l'électrode définitive. Dans un deuxième temps, le ou les générateur(s) d'impulsions sont implantés en anesthésie générale. La SCP pour les mouvements anormaux a une très bonne efficacité et un risque de complications graves faible quoique non nul. Les complications liées au matériel sont les plus fréquentes. Deep brain stimulation (DBS) requires the surgical implantation of a system including brain electrodes and impulsion generator(s). The nuclei targeted by the stereotaxic implantation methodology have to be visualized at best by high resolution imaging. The surgical procedure for implanting the electrodes is performed if possible under local anaesthesia to make electro-physiological measurements and to test intra-operatively the effect of the stimulation, in order to optimize the position of the definitive electrode. In a second step, the impulsion generator(s) are implanted under general anaesthesia. DBS for movement disorders has a very good efficacy and a low albeit non-zero risk of serious complications. Complications related to the material are the most common.

Cancer testiculaire: un modèle pour optimiser le suivi radiologique [Testicular cancer: a model to optimize the radiological follow-up].

Le cancer testiculaire, bien que peu fréquent, revêt une importance particulière en oncologie ; il représente actuellement un modèle pour optimiser un suivi radiologique tout en essayant de diminuer l'apparition de tumeurs radio-induites.En effet, cette pathologie présente un taux très élevé de survie nécessitant, au vu du jeune âge des patients, des bilans radiologiques à long terme, auxquels pourront être liés des effets secondaires, en particulier les tumeurs secondaires.Afin de diminuer cela, les recommandations de prise en charge ont évolué et les protocoles de radiologie s'améliorent afin d'exposer à moins de rayonnements ionisants pour un résultat identique.Il est donc devenu primordial de maintenir un suivi optimal tout en essayant d'en minimiser la toxicité. Despite being rare cancers, testicular seminoma and non-seminoma play an important role in oncology: they represent a model on how to optimize radiological follow-up, aiming at a lowest possible radiation exposure and secondary cancer risk. Males diagnosed with testicular cancer undergo frequently prolonged follow-up with CT-scans with potential toxic side effects, in particular secondary cancers. To reduce the risks linked to ionizing radiation, precise follow-up protocols have been developed. The number of recommended CT-scanners has been significantly reduced over the last 10 years. The CT scanners have evolved technically and new acquisition protocols have the potential to reduce the radiation exposure further.