Prophylaxis with resin in wood ants

Animals may use plant compounds to defend themselves against parasites. Wood ants, Formica paralugubris, incorporate pieces of solidified conifer resin into their nests. This behaviour inhibits the growth of bacteria and fungi in nest material and protects the ants against some detrimental microorganisms. Here, we studied the resin-collecting behaviour of ants under field and laboratory conditions. First, we focused on an important assumption of the self-medication hypothesis, which is that the animals deliberately choose the active plant material. In field cafeteria tests, the ants indeed showed a strong preference for resin over twigs and stones, which are building materials commonly encountered in their environment. We detected seasonal variation in the choice of ants: the preference for resin over twigs was more pronounced in spring than in summer, whereas in autumn the ants collected twigs and resin at equal rates. Second, we found almost similar seasonal patterns when comparing the collecting rates of pieces of wood that had been impregnated with turpentine (a distillate of oleoresin) and untreated pieces of wood, which reveals that the preference for resin is based on odour cues. Third, we tested whether the collection of resin is prophylactic or therapeutic. We found that the relative collection rate of resin versus stones did not depend on an experimental infection with the entomopathogenic fungus Metarhizium anisopliae in laboratory colonies. Together, these results show that the ants deliberately choose the resin and suggest that resin collection is prophylactic rather than therapeutic.

RP 59500 prophylaxis of experimental endocarditis due to erythromycin-susceptible and -resistant isogenic pairs of viridans group streptococci.

RP 59500 is a new injectable streptogramin composed of two synergistic components (quinupristin and dalfopristin) which are active against a number of erythromycin-susceptible and -resistant gram-positive bacteria. The following experiments investigate the ability of RP 59500 to prevent experimental endocarditis due to either of two erythromycin-susceptible streptococcal isolates or their constitutively erythromycin-resistant Tn916 delta E transconjugants. RP 59500 had low MICs (0.125 to 0.5 mg/liter) for all four test organisms and was substantially bactericidal in vitro. Rats with catheter-induced aortic vegetations were given single-dose antibiotic prophylaxis 30 to 60 min before bacterial inoculation through a computerized pump system which permitted the simulation of drug kinetics for humans produced by either 7 mg of RP 59500 per kg of body weight or 1 g of vancomycin. Single-dose RP 59500 prophylaxis successfully prevented endocarditis due to both the erythromycin-susceptible parent strains and their erythromycin-resistant derivatives in rats challenged with the minimal inoculum infecting 90% of controls. In addition, RP 59500 also prevented infection in animals challenged with fivefold-larger inocula of the erythromycin-susceptible parent strains. Vancomycin successfully prevented endocarditis due to any of the four test organisms. These results underline the in vivo efficacy of RP 59500 against both erythromycin-susceptible and -resistant streptococci. Such good results against the resistant strains would not be expected with erythromycin or clindamycin, which are the standard macrolidelincosamide-streptogramin antibiotics used for endocarditis prophylaxis in humans. An oral form of RP 59500 which might advantageously replace some of the older prophylactic regimens is currently being developed.

Apport de la psychanalyse en oncogénétique prédictive

La médecine prédictive évalue la probabilité que des personnes portant des mutations génétiques constitutionnelles puissent développer une maladie donnée, comme par exemple une tumeur maligne (oncogénétique). Dans le cas des prédispositions génétiques au cancer, des mesures particulières de surveillance et de prévention sont discutées en fonction de l'évaluation des risques et des résultats de l'analyse génétique, y compris certains traitements préventifs allant, à l'extrême, jusqu'à l'intervention chirurgicale prophylactique (ex : mastectomie et/ou ovariectomie). Cette étude est basée sur une interprétation psychanalytique du récit de sujets ayant entrepris une démarche en oncogénétique et vise à analyser l'impact psychique : a) du résultat de l'analyse génétique et b) de la construction de l'arbre généalogique. Elle a été conduite dans l'Unité d'oncogénétique et de prévention des cancers (UOPC) du Service d'oncologie des Hôpitaux Universitaires de Genève (HUG). L'UOPC assure des consultations de conseil génétique spécialisé pour les personnes ayant des antécédents personnels et/ou familiaux de maladies tumorales suggestifs de l'existence de prédispositions génétiques au cancer. La population de cette étude comprend 125 sujets suivis lors des différentes étapes du dépistage, pour un total de 289 consultations et 50 entretiens individuels. Cette recherche montre que les sujets asymptomatiques réélaborent de façon personnelle, soit le résultat génétique (négatif ou positif), soit l'acte de prédiction. En revanche, ceux qui ont développé un cancer expriment des sentiments d'angoisse, comme s'ils subissaient les effets d'un destin inéluctable qui s'est effectivement réalisé. Par ailleurs, l'arbre généalogique est réinterprété de façon personnelle, laissant apparaître des aspects refoulés ou niés qui peuvent resurgir. Lorsque d'autres membres de la famille sont sollicités pour préciser les liens génétiques et/ou être soumis en première intention à l'analyse génétique, le sujet exprime sa difficulté de dépendre d'autres personnes pour connaître son propre statut biologique. D'une façon générale, on constate que là où la médecine prédictive réalise son acte de prévision, le sujet répond de façon imprévisible. Dans l'optique de la psychanalyse, cette imprévisibilité est liée aux aspects du « désir inconscient ». Cette étude montre aussi qu'on ne peut pas considérer le dépistage génétique comme étant la cause directe du traumatisme. L'effort doit porter sur le fait que le sujet puisse se réapproprier ce qui lui arrive, et exprimer progressivement sa souffrance spécifique en jeu dans le processus de prédiction pour créer un écart entre la vérité médicale et la sienne. L'espace de la parole devient ainsi le lieu d'un travail privilégié. La psychanalyse opère donc pour que le résultat génétique se détache de l'acte de prédiction, c'est-à-dire qu'il redevienne un moment de la vie du sujet qui puisse s'articuler comme sa propre histoire personnelle. The aim of predictive medicine is to assess the probability that individuals carrying germ-line mutations will develop certain diseases, for instance cancer (oncogenetics). In predictive oncology, particular surveillance and prevention measures are discussed with these patients in relation to risk assessment and results of genetic testing, including preventive care which can, in extremes cases, lead to prophylactic surgery (i.e. mastectomy and/or ovariectomy). This study is based on a psychoanalytic interpretation of subjects' narration of the oncogenetic process and aims at analyzing the psychological impact of a) genetic testing and b) the construction of the family tree. It was carried out at the Oncogenetics and cancer prevention unit (Unité d'oncogénétique et de prévention des cancers) from the Geneva University Hospitals (Hôpitaux Universitaires de Genève, HUG) which organizes genetic counselling for individuals having personal and/or family history suggestive of genetic predisposition to cancer. The study population comprises 125 patients followed during the successive steps of genetic counselling, for a total of 289 consultations and 50 personal interviews. This research shows that asymptomatic subjects re-elaborate in a personal way either the results of genetic testing (negative or positive) or the act of prediction. Conversely, those having developed cancer express feelings of anguish, as if they were undergoing the effects of a destiny which effectively happened. Its sight remains a difficult step of the oncogenetic process, as psychological aspects which were repressed or denied can re-appear. When some family members are solicited to help reconstructing the genetic relationships, sometimes being themselves submitted first to genetic testing, the study subject expresses the difficulty to depend on other persons to learn more about his own biological status. In this study, we observe that, in parallel to predictions delivered by the process of predictive medicine, the subject actually answers unpredictably. With a psychoanalytic perspective, this unpredictability is related to an "unconscious desire". We also find that we cannot consider that genetic screening is a direct cause of psychological trauma. Our efforts must rely on allowing the subject to re-appropriate himself what is happening, to let him progressively express his own suffering of the prediction in order to create a gap between the medical reality and his own. In this process, "speech" is needed to let this happening. Psychoanalysis works in such a way that the genetic testing's result becomes distinct from the act of prediction, a moment of the subject's life expressed as his own personal history.

Towards a system analysis of the early steps of infectious endocarditis pathogenesis

L'endocardite infectieuse (EI) est une maladie potentiellement mortelle qui doit être prévenue dans toute la mesure du possible. Au cours de ces dernières 50 années, les recommandations Américaines et Européennes pour la prophylaxie de PEI proposaient aux patients à risques de prendre un antibiotique, préventif avant de subir une intervention médico-chirurgicale susceptible d'induire une bactériémie transitoire. Cependant, des études épidémiologiques récentes ont montré que la plupart des EI survenaient en dehors de tous actes médico-chirurgicaux, et indépendamment de la prise ou non de prophylaxie antibiotique . L'EI pourrait donc survenir suite à la cumulation de bactériémies spontanées de faibles intensités, associées à des activités de la vie courante telle que le brossage dentaire pour le streptocoques, ou à partir de tissus colonisés ou de cathéters infectés pour les staphylocoques. En conséquence, les recommandations internationales pour la prophylaxie de PEI ont été revues et proposent une diminution drastique de l'utilisation d'antibiotiques. Cependant, le risque d'EI représenté par le cumul de bactériémies de faibles intensités n'a pas été démontré expérimentalement. Nous avons développé un nouveau modèle d'EI expérimentale induite par une inoculation en continu d'une faible quantité de bactéries, simulant le cumul de bactériémies de faibles intensités chez l'homme, et comparé l'infection de Streptococcus gordonii et de Staphylococcus aureus dans ce modèle avec celle du modèle d'IE induite par une bactériémie brève, mais de forte intensité. Nous avons démontré, après injection d'une quantité égale de bactéries, que le nombre de végétations infectées était similaire dans les deux types d'inoculations. Ces résultats expérimentaux ont confirmé l'hypothèse qu'une exposition cumulée à des bactériémies de faibles intensités, en dehors d'une procédure médico-chirurgicale, représentait un risque pour le développement d'une El, comme le suggéraient les études épidémiologiques. En plus, ces résultats ont validé les nouvelles recommandations pour la prophylaxie de l'El, limitant drastiquement l'utilisation d'antibiotiques. Cependant, ces nouvelles recommandations laissent une grande partie (> 90%) de cas potentiels d'EI sans alternatives de préventions, et des nouvelles stratégies prophylactiques doivent être investiguées. Le nouveau modèle d'EI expérimentale représente un modèle réaliste pour étudier des nouvelles mesures prophylactiques potentielles appliquées à des expositions cumulées de bactériémies de faible nombre. Dans un contexte de bactériémies spontanées répétitives, les antibiotiques ne peuvent pas résoudre le problème de la prévention de l'EI. Nous avons donc étudié la une alternative de prévention par l'utilisation d'agents antiplaquettaires. La logique derrière cette approche était basée sur le fait que les plaquettes sont des composants clés dans la formation des végétations cardiaques, et le fait que les bactéries capables d'interagir avec les plaquettes sont plus enclines à induire une El. Les agents antiplaquettaires utilisés ont été l'aspirine (inhibiteur du COX1), la ticlopidine (inhibiteur du P2Y12, le récepteur de l'ADP), et l'eptifibatide et Pabciximab, deux inhibiteurs du GPIIb/IIIa, le récepteur plaquettaire pour le fibrinogène. Les anticoagulants étaient le dabigatran etexilate, inhibant lathrombine et l'acenocumarol, un antagoniste de la vitamine K. L'aspirine, la ticlopidine ou l'eptifibatide seuls n'ont pas permis de prévenir l'infection valvulaire (> 75% animaux infectés). En revanche, la combinaison d'aspirine et de ticlopidine, aussi bien que l'abciximab, ont protégé 45% - 88% des animaux de l'EI par S. gordonii et par S. aureus. L'antithrombotique dabigatran etexilate à protégé 75% des rats contre l'EI par S. aureus, mais pas (< 30% de protection) par S. gordonii. L'acenocoumarol n'a pas eu d'effet sur aucun des deux organismes. En général, ces résultats suggèrent un possible rôle pour les antiplaquettaires et du dabigatran etexilate dans la prophylaxie de l'EI dans un contexte de bactériémies récurrentes de faibles intensités. Cependant, l'effet bénéfique des antiplaquettaires doit être soupesé avec le risque d'hémorragie inhérent à ces molécules, et le fait que les plaquettes jouent un important rôle dans les défenses de l'hôte contre les infections endovasculaires. En plus, le double effet bénéfique du dabigatran etexilate devrait être revu chez les patients porteurs de valves prothétiques, qui ont besoin d'une anticoagulation à vie, et chez lesquels l'EI à S. aureus est associée avec une mortalité de près de 50%. Comme l'approche avec des antiplaquettaires et des antithrombotiques pourrait avoir des limites, une autre stratégie prophylactique pourrait être la vaccination contre des adhésines de surfaces des pathogènes. Chez S. aureus, la protéine de liaison au fibrinogène, ou dumping factor A (ClfA), et la protéine de liaison à la fibronectine (FnbpA) sont des facteurs de virulence nécessaires à l'initiation et l'évolution de PEI. Elles représentent donc des cibles potentielles pour le développement de vaccins contre cette infection. Récemment, des nombreuses publications ont décrit que la bactérie Lactococcus lactis pouvait être utilisée comme vecteur pour la diffusion d'antigènes bactériens in vivo, et que cette approche pourrait être une stratégie de vaccination contre les infections bactériennes. Nous avons exploré l'effet de l'immunisation par des recombinant de L. lactis exprimant le ClfA, la FnbpA, ou le ClfA ensemble avec et une forme tronquée de la FnbpA (Fnbp, comprenant seulement le domaine de liaison à la fibronectine mais sans le domaine A de liaison au fibrinogène [L. lactis ClfA/Fnbp]), dans la prophylaxie de PIE expérimentale à S. aureus. L. lactis ClfA a été utilisés comme agent d'immunisation contre la souche S. aureus Newman (qui a particularité de n'exprimer que le ClfA, mais pas la FnbpA). L. lactis ClfA, L. lactis FnbpA, et L. lactis ClfA/Fnbp, ont été utilisé comme agents d'immunisation contre une souche isolée d'une IE, S. aureus P8 (exprimant ClfA et FnbpA). L'immunisation avec L. lactis ClfA a généré des anticorps anti-ClfA fonctionnels, capables de bloquer la liaison de S. aureus Newman au fibrinogène in vitro et protéger 13/19 (69%) animaux d'une El due à S. aureus Newman (P < 0.05 comparée aux contrôles). L'immunisation avec L. lactis ClfA, L. lactis FnbpA, ou L. lactis ClfA/Fnbp, a généré des anticorps contre chacun de ces antigènes. Cependant, ils n'ont pas permis de bloquer l'adhésion de S. aureus P8 au fibrinogène et à la fibronectine in vitro. De plus, l'immunisation avec L. lactis ClfA ou L. lactis FnbpA s'est avérée inefficace in vivo (< 10% d'animaux protégés d'une El) et l'immunisation avec L. lactis ClfA/Fnbp a fourni une protection limitée de l'EI (8/23 animaux protégés; P < 0.05 comparée aux contrôles) après inoculation avec S. aureus P8. Dans l'ensemble, ces résultats indiquent que L. lactis est un système efficace pour la présentation d'antigènes in vivo et potentiellement utile pour la prévention de PEI à S. aureus. Cependant, le répertoire de protéines de surface de S. aureus capable d'évoquer une panoplie d'anticorps efficace reste à déterminer.. En résumé, notre étude a démontré expérimentalement, pour la première fois, qu'une bactériémie répétée de faible intensité, simulant la bactériémie ayant lieu, par exemple, lors des activités de la vie quotidienne, est induire un taux d'EI expérimentale similaire à celle induite par une bactériémie de haute intensité suite à une intervention médicale. Dans ce contexte, où l'utilisation d'antibiotiques est pas raisonnable, nous avons aussi montré que d'autres mesures prophylactiques, comme l'utilisation d'agents antiplaquettaires ou antithrombotiques, ou la vaccination utilisant L. lactis comme vecteur d'antigènes bactériens, sont des alternatives prometteuses qui méritent d'être étudiées plus avant. Thesis Summary Infective endocarditis (IE) is a life-threatening disease that should be prevented whenever possible. Over the last 50 years, guidelines for IE prophylaxis proposed the use of antibiotics in patients undergoing dental or medico-surgical procedures that might induce high, but transient bacteremia. However, recent epidemiological studies indicate that IE occurs independently of medico-surgical procedures and the fact that patients had taken antibiotic prophylaxis or not, i.e., by cumulative exposure to random low-grade bacteremia, associated with daily activities (e.g. tooth brushing) in the case of oral streptococci, or with a colonized site or infected device in the case of staphylococci. Accordingly, the most recent American and European guidelines for IE prophylaxis were revisited and updated to drastically restrain antibiotic use. Nevertheless, the relative risk of IE represented by such cumulative low-grade bacteremia had never been demonstrated experimentally. We developed a new model of experimental IE due to continuous inoculation of low-grade bacteremia, mimicking repeated low-grade bacteremia in humans, and compared the infectivity of Streptococcus gordonii and Staphylococcus aureus in this model to that in the model producing brief, high-level bacteremia. We demonstrated that, after injection of identical bacterial numbers, the rate of infected vegetations was similar in both types of challenge. These experimental results support the hypothesis that cumulative exposure to low-grade bacteremia, outside the context of procedure-related bacteremia, represents a genuine risk of IE, as suggested by human epidemiological studies. In addition, they validate the newer guidelines for IE prophylaxis, which drastic limit the procedures in which antibiotic prophylaxis is indicated. Nevertheless, these refreshed guidelines leave the vast majority (> 90%) of potential IE cases without alternative propositions of prevention, and novel strategies must be considered to propose effective alternative and "global" measures to prevent IE initiation. The more realistic experimental model of IE induced by low-grade bacteremia provides an accurate experimental setting to study new preventive measures applying to cumulative exposure to low bacterial numbers. Since in a context of spontaneous low-grade bacteremia antibiotics are unlikely to solve the problem of IE prevention, we addressed the role of antiplatelet and anticoagulant agents for the prophylaxis of experimental IE induced by S. gordonii and S. aureus. The logic of this approach was based on the fact that platelets are key players in vegetation formation and vegetation enlargement, and on the fact that bacteria capable of interacting with platelets are more prone to induce IE. Antiplatelet agents included the COX1 inhibitor aspirin, the inhibitor of the ADP receptor P2Y12 ticlopidine, and two inhibitors of the platelet fibrinogen receptor GPIIb/IIIa, eptifibatide and abciximab. Anticoagulants included the thrombin inhibitor dabigatran etexilate and the vitamin K antagonist acenocoumarol. Aspirin, ticlopidine or eptifibatide alone failed to prevent aortic infection (> 75% infected animals). In contrast, the combination of aspirin with ticlopidine, as well as abciximab, protected 45% to 88% of animals against IE due to S. gordonii and S. aureus. The antithrombin dabigatran etexilate protected 75% of rats against IE due to S. aureus, but failed (< 30% protection) against S. gordonii. Acenocoumarol had no effect against any bacteria. Overall, these results suggest a possible role for antiplatelet agents and dabigatran etexilate in the prophylaxis of IE in humans in a context of recurrent low- grade bacteremia. However, the potential beneficial effect of antiplatelet agents should be balanced against the risk of bleeding and the fact that platelets play an important role in the host defenses against intravascular infections. In addition, the potential dual benefit of dabigatran etexilate might be revisited in patients with prosthetic valves, who require life-long anticoagulation and in whom S. aureus IE is associated with high mortality rate. Because the antiplatelet and anticoagulant approach might be limited in the context of S. aureus bacteremia, other prophylactic strategies for the prevention of S. aureus IE, like vaccination with anti-adhesion proteins was tested. The S. aureus surface proteins fibrinogen-binding protein clumping-factor A (ClfA) and the fibronectin-binding protein A (FnbpA) are critical virulence factors for the initiation and development of IE. Thus, they represent key targets for vaccine development against this disease. Recently, numerous reports have described that the harmless bacteria Lactococcus lactis can be used as a bacterial vector for the efficient delivery of antigens in vivo, and that this approach is a promising vaccination strategy against bacterial infections. We therefore explored the immunization capacity of non- living recombinant L. lactis ClfA, L. lactis FnbpA, or L. lactis expressing ClfA together with Fnbp (a truncated form of FnbpA with only the fibronectin-binding domain but lacking the fibrinogen-binding domain A [L. lactis ClfA/Fnbp]), to protect against S. aureus experimental IE. L. lactis ClfA was used as immunization agent against the laboratory strain S. aureus Newman (expressing ClfA, but lacking FnbpA). L. lactis ClfA, L. lactis FnbpA, as well as L. lactis ClfA/Fnbp, were used as immunization agents against the endocarditis isolate S. aureus P8 (expressing both ClfA and FnbpA). Immunization with L. lactis ClfA produced anti-ClfA functional antibodies, which were able to block the binding of S. aureus Newman to fibrinogen in vitro and protect 13/19 (69%) animals from IE due to S. aureus Newman (P < 0.05 compared to controls). Immunization with L. lactis ClfA, L. lactis FnbpA or L. lactis ClfA/Fnbp, produced antibodies against each antigen. However, they were not sufficient to block S. aureus P8 binding to fibrinogen and fibronectin in vitro. Moreover, immunization with L. lactis ClfA or L. lactis FnbpA was ineffective (< 10% protected animals) and immunization with L. lactis ClfA/Fnbp conferred limited protection from IE (8/23 protected animals; P < 0.05 compared to controls) after challenge with S. aureus P8. Together, these results indicate that L. lactis is an efficient delivering antigen system potentially useful for preventing S. aureus IE. They also demonstrate that expressing multiple antigens in L. lactis, yet to be elucidated, will be necessary to prevent IE due to clinical S. aureus strains fully equipped with virulence determinants. In summary, our study has demonstrated experimentally, for the first time, the hypothesis that low-grade bacteremia, mimicking bacteremia occurring outside of a clinical intervention, is equally prone to induce experimental IE as high-grade bacteremia following medico-surgical procedures. In this context, where the use of antibiotics for the prophylaxis of IE is limited, we showed that other prophylactic measures, like the use of antiplatelets, anticoagulants, or vaccination employing L. lactis as delivery vector of bacterial antigens, are reasonable alternatives that warrant to be further investigated.

Novel immunotherapeutic strategies against human papillomavirus type 16 (HPV 16) induced lesions and cervical cancer

RESUME Le cancer du col de l'utérus, deuxième cause de mort par cancer chez la femme, a pu être associé à une infection par plusieurs types de virus du Papillome Humain (HPV), et en particulier HPV 16. Les vaccins prophylactiques sont efficaces à prévenir le cancer du col utérin alors que les lésions de haut grade sont généralement traitées par ablation chirurgicale et par d'éventuels traitements additionnels. Les risques de récurrence liés aux ablations et le taux de mortalité (50%) lié au cancer, démontrent le besoin de développer des stratégies alternatives afin de cibler les lésions précancéreuses. A ce jour, les vaccins thérapeutiques ont démontré peu de résultats cliniques, contrastant avec les régressions de tumeurs ectopiques observées après vaccination dans des modèles murins avec tumeurs associées à HPV. L'induction de réponses immunitaires protectrices dans la muqueuse génitale semble être cruciale pour l'efficacité des vaccins thérapeutiques HPV et évaluer leur efficacité dans un modèle murin avec tumeurs-HPV génitales représente un pré-requis important avant de procéder à des études cliniques. Par conséquent, nous avons établi un modèle murin orthotopique où des tumeurs se développent dans (a muqueuse génitale après une instillation intra-vaginale (i.vag) de cellules tumorales exprimant les oncogènes E6/E7 d'HPV 16 et transduites par un vecteur lentiviral codant la luciferase afin de suivre le développement de ces tumeurs in vivo par imagerie. La caractérisation histologique a démontré que les tumeurs grandissaient dans l'épithélium vaginal et en accord avec leur localisation, des cellules Τ CD8 spécifiques à E7 induites par la tumeur n'étaient détectées que dans la muqueuse génitale et les ganglions drainants. Une infiltration de cellules Τ régulatrices a aussi été mise en évidence, empêchant la régression spontanée de ces tumeurs. Par conséquent, ce modèle devrait être plus adéquat pour tester des stratégies thérapeutiques, étant donné qu'il partage certaines similarités immunologiques avec les lésions génitales naturelles causées par HPV. Etant donné que les oncogènes E6 et E7 d'HPV sont nécessaires à la maintenance du phénotype cancéreux des cellules cervicales, elles représentent des antigènes cibles pour la vaccination thérapeutique. Nous avons démontré que des souris immunisées par voie sous-cutanée (s.c.) avec une dose d'un vaccin à base de polypeptide E7 d'HPV 16 et d'adjuvants, présentaient de nombreuses cellules Τ CD8 sécrétant de l'IFN-γ spécifiquement à E7 dans leurs organes lymphatiques mais également dans la muqueuse génitale. De plus, le manque de corrélation entre les réponses spécifiques mesurées dans la périphérie et dans la muqueuse génitale souligne la nécessité et l'importance de déterminer les réponses immunitaires localement là où les lésions dues à HPV se développent. Si une vaccination par voie muqueuse est plus propice à traiter/régresser des infections génitales/tumeurs que le voie parentérale est un sujet débattu. Nos données montrent que seule la voie s.c. était capable de régresser la quasi totalité des tumeurs génitales chez la souris bien que des réponses CD8 spécifiques à E7 similaires étaient mesurées dans la muqueuse génitale après des vaccinations intra-nasale et i.vag. Afin d'augmenter la réponse spécifique au vaccin dans la muqueuse génitale, des immunostimulants ont été administrés par voie i.vag après vaccination. Nous avons démontré qu'une application i.vag d'agonistes des Toll like receptors après une vaccination s.c. induisait de manière significative une augmentation des cellules Τ CD8 sécrétant de l'IFN-γ spécifiquement à E7 dans la muqueuse génitale. Plus précisément et concernant les CpG et Poly l:C, l'effet était probablement associé à une attraction locale des cellules Τ CD8 et deuxièmement dépendait respectivement des voies de signalisation TLR9 et TLR3/Mda5. Finalement, cette stratégie combinatoire a permis de régresser des grosses tumeurs génitales chez la souris, suggérant qu'une telle immunothérapie pourrait adéquatement traiter des lésions dues à HPV chez les femmes. SUMMARY Cervical cancer is the second leading cause of cancer mortality in women worldwide and results from an infection with a subset of Human Papillomavirus (HPV), HPV 16 representing the most prevalent type. The available prophylactic vaccines are an effective strategy to prevent cervical cancer while already established high grade lesions usually require surgical ablation of lesion with possible additional treatments. Recurrence risks linked to conventional ablations and the high mortality (50%) related to cervical cancer demonstrate the need for alternative strategies like immunotherapies to target pre¬cancerous lesions. Until now, therapeutic vaccines only showed limited clinical results, which strongly contrast with the regression of ectopic tumors observed in the available murine HPV tumor models after vaccination. Induction of protective immune responses in the genital mucosa (GM) may be crucial for efficacy of HPV therapeutic vaccines and evaluating their efficacy in a murine model with genital HPV- tumors represents an important prerequisite for clinical trials. Thus, we have here established an orthotopic mouse model where tumors in the GM develop after an intravaginal (i.vag) instillation of HPV 16 E6/E7 oncogenes-expressing tumor cells transduced with a luciferase encoding lentivirus vector for in vivo imaging of tumor growth. Histological characterization showed that tumor grew within the vaginal epithelium and according to their mucosal location tumor- induced E7-specific CD8 Τ cells were restricted to the GM and genital draining lymph nodes together with high Τ regulatory cells infiltrates preventing spontaneous regression. Consequently, sharing several immunological similarities with natural genital HPV lesions, this novel genital tumor model may be more adequate to test therapeutic strategies. As E6 and/or E7 HPV oncogenes expression is required for the maintenance of the cancerous phenotype of cervical cells, they represent target antigens for therapeutic vaccination. We reported that mice subcutaneously (s.c.) immunized once with an adjuvanted HPV 16 E7 polypeptide vaccine harbored high E7-specific IFN-γ secreting CD8 Τ cells in their lymphoid organs and more importantly in the GM. In addition, the lack of correlation between specific responses measured in the periphery with those measured in the GM highlighted the necessity and relevance to determine the immune responses locally where HPV 16-induced lesions develop. Whether a mucosal route of immunization is better to treat/regress genital infections/tumors than parenteral immunization is still debated. Our data shows that although similar E7-specific IFN-γ secreting CD8 Τ cells responses were measured in the GM upon mucosal routes of E7 vaccine delivery (nasal and vaginal immunizations), only the s.c immunization was able to regress at least all genital tumors in mice. To further increase the vaccine-specific responses in the GM, immunostimulatory agents were i.vag administrated after vaccination. We demonstrated that a single i.vag application of toll like receptor (TLR) agonists after a s.c. E7 vaccination induced a significant increase of E7-specific IFN-γ secreting CD8 Τ cells in the GM. More precisely, regarding CpG and Poly l:C, the effect is most probably associated with a local attraction of total CD8 Τ cells and secondly depends on TLR9 and TLR3/Mda5 signaling pathways, respectively. Finally, this combinatorial strategy induced tumor regression in mice harboring large genital tumors, suggesting that such an immunotherapy could be adequate to treat HPV-induced lesions in women.

Kartagener syndrome: an uncommon cause of neonatal respiratory distress?

We report a newborn with respiratory distress and situs inversus totalis. The diagnosis of primary ciliary dyskinesia was confirmed by both ultrastructural and functional investigations. The immotile cilia syndrome was suspected because of respiratory distress, situs inversus, abnormal nasal discharge and hyperinflated chest X-ray. We suggest that ultrastructural and functional investigations of the respiratory mucosa should be done in any newborn with respiratory distress without explanation for the respiratory problems. Establishment of the correct diagnosis at an early stage may allow to improve the prognosis provided prophylactic physiotherapy, vaccinations, and aggressive antibiotic treatment of intercurrent respiratory infections are instituted. CONCLUSION Despite its rarity, primary ciliary dyskinesia should be considered in unexplained cases of neonatal distress.

Mixed medullary-papillary carcinoma of the thyroid: report of a case and review of the literature.

BACKGROUND: Mixed medullary-follicular thyroid carcinoma denotes a rare and heterogeneous group of tumors displaying morphological and immunophenotypical features of both origins within the same lesion. METHOD: We report a case of a 41-year-old woman with a lump in the right side of the neck, increasing in pain and size over several weeks. Serum levels of calcitonine (1140 ng/L) and carcinoembryonic antigen (288 microg/L) were very high. Fine-needle aspiration cytology suggested a diagnosis of medullary thyroid carcinoma. Total thyroidectomy, along with bilateral functional neck and mediastinal lymph-node dissection, were performed. RESULTS: The histopathological examination yielded a diagnosis of medullary carcinoma in the right thyroid lobe, closely intermingled with a nonencapsulated classical papillary carcinoma. One ipsilateral lymph node showed micrometastasis of the medullary counterpart. CONCLUSION: When compared with other cases reported in literature, this particular presentation should be recognized, if required, morphologic and functional criteria are used. The treatment is mostly surgical, driven by the medullary component. The presence of micrometastasis in 1 ipsilateral cervical lymph-node underlines the importance of cervicomediastinal lymph-node dissection and careful searching for metastatic disease.

Neurally Adjusted Ventilatory Assist (NAVA) improves the matching of diaphragmatic electrical activity and tidal volume in comparison to pressure support (PS) under non invasive ventilation

INTRODUCTION. Patient-ventilator asynchrony is a frequent issue in non invasivemechanical ventilation (NIV) and leaks at the patient-mask interface play a major role in itspathogenesis. NIV algorithms alleviate the deleterious impact of leaks and improve patient-ventilator interaction. Neurally adusted ventilatory assist (NAVA), a neurally triggered modethat avoids interferences between leaks and the usual pneumatic trigger, could further improvepatient-ventilator interaction in NIV patients.OBJECTIVES. To evaluate the feasibility ofNAVAin patients receiving a prophylactic postextubationNIV and to compare the respective impact ofPSVandNAVAwith and withoutNIValgorithm on patient-ventilator interaction.METHODS. Prospective study conducted in 16 beds adult critical care unit (ICU) in a tertiaryuniversity hospital. Over a 2 months period, were included 17 adult medical ICU patientsextubated for less than 2 h and in whom a prophylactic post-extubation NIV was indicated.Patients were randomly mechanically ventilated for 10 min with: PSV without NIV algorithm(PSV-NIV-), PSV with NIV algorithm (PSV-NIV+),NAVAwithout NIV algorithm (NAVANIV-)and NAVA with NIV algorithm (NAVA-NIV+). Breathing pattern descriptors, diaphragmelectrical activity, leaks volume, inspiratory trigger delay (Tdinsp), inspiratory time inexcess (Tiexcess) and the five main asynchronies were quantified. Asynchrony index (AI) andasynchrony index influenced by leaks (AIleaks) were computed.RESULTS. Peak inspiratory pressure and diaphragm electrical activity were similar in thefour conditions. With both PSV and NAVA, NIV algorithm significantly reduced the level ofleak (p\0.01). Tdinsp was not affected by NIV algorithm but was shorter in NAVA than inPSV (p\0.01). Tiexcess was shorter in NAVA and PSV-NIV+ than in PSV-NIV- (p\0.05).The prevalence of double triggering was significantly lower in PSV-NIV+ than in NAVANIV+.As compared to PSV,NAVAsignificantly reduced the prevalence of premature cyclingand late cycling while NIV algorithm did not influenced premature cycling. AI was not affectedby NIV algorithm but was significantly lower in NAVA than in PSV (p\0.05). AIleaks wasquasi null with NAVA and significantly lower than in PSV (p\0.05).CONCLUSIONS. NAVA is feasible in patients receiving a post-extubation prophylacticNIV. NAVA and NIV improve patient-ventilator synchrony in different manners. NAVANIV+offers the best patient-ventilator interaction. Clinical studies are required to assess thepotential clinical benefit of NAVA in patients receiving NIV.

Endocarditis prophylaxis revisited: experimental evidence of efficacy and new Swiss recommendations. Swiss Working Group for Endocarditis Prophylaxis.

Because of its severity, it is agreed that infectious endocarditis should be prevented whenever possible. Determining adequate prophylactic measures involves establishing (a) the patients at risk, (b) the procedures that might provoke bacteraemia, (c) the most effective prophylactic regimen, and (d) a balance between the risks of side effects from prophylaxis and of developing infectious endocarditis. Patients at risk and procedures inducing bacteraemia have been identified by clinical studies. On the other hand, the efficacy of prophylactic antibiotics has been based on animal studies. Randomised, placebo-controlled studies do not exist in humans because they would require large patient numbers and would raise ethical issues due to the severity of the disease. Case-control studies have indicated that infectious endocarditis prophylaxis is effective, but prevents only a limited number of cases. Animal experiments have revealed several key issues for human application. First, antibiotics do not prevent the early stages of valve colonisation, but rather kill the microorganisms after their attachment to the cardiac lesions. Second, the duration of antibiotic presence in the serum is critical. Under experimental conditions, the drugs must remain above their minimal inhibitory concentration for the organisms for > or = 10 h, to allow time for bacterial clearance from the valves. Third, antibiotic-induced killing is not the only mechanism allowing bacterial clearance. Other factors, such as platelet microbicidal proteins, may act in concert with the drugs to sterilise the lesions. Recommendations for prophylaxis have recently been revised in Europe and the USA. New information has improved the definition of groups at risk. Since most cases of infectious endocarditis are not preceded by medical procedures, primary prevention of infectious endocarditis should target infected foci responsible for spontaneous bacteraemia (e.g. poor dental hygiene). The purpose of this article is to update the existing recommendations in Switzerland, under the perspective of changing epidemiology, the availability of new drugs, and harmonisation with recommendations in other countries.

Opportunity for catch-up HPV vaccination in young women after first delivery.

Background Early age at first delivery has been identified as a risk factor for high-risk HPV-type infection and cervical cancer development. Methods A cross-sectional study was carried out in a large public maternity hospital in Sao Paulo, Brazil. During June 2006 to February 2007, 301 women aged 15-24 years who gave birth to their first child were recruited between 43 and 60 days after delivery. Detection of HPV DNA in cervical specimens was performed using a standardised PCR protocol with PGMY09/11 primers. The association of selected factors with HPV infection was assessed by using a Generalised Linear Model. Results HPV DNA was detected in 58.5% (95% CI 52.7% to 64.0%) of the enrolled young women. The most common types of HPV found were: HPV16, HPV51, HPV52, HPV58 and HPV71. The overall prevalence of HPV types targeted by the HPV prophylactic vaccines was: HPV 16-12.0%, HPV 18-2.3% and HPV 6 and 11 4.3%. In the multivariate analysis, only age (inversely, p for trend=0.02) and smoking habits were independently associated with HPV infection. Conclusions The findings show that these young primiparous women had high cervical HPV prevalence, suggesting that this is a high-risk group for cervical cancer development. Nevertheless, 17.3% were positive for any of the four HPV types included in HPV vaccines (HPV6, 11, 16 or 18), with 13.3% positive for HPV 16 or 18 and only 1.0% having both vaccine related-oncogenic HPV types. Thus, young primiparous women could benefit from catch-up HPV vaccination programmes.

Vaccination Strategies against Highly Pathogenic Arenaviruses: The Next Steps toward Clinical Trials.

Vaccination is one of the most valuable weapons against infectious diseases and has led to a significant reduction in mortality and morbidity. However, for most viral hemorrhagic fevers caused by arenaviruses, no prophylactic vaccine is available. This is particularly problematic as these diseases are notoriously difficult to diagnose and treat. Lassa fever is globally the most important of the fevers caused by arenaviruses, potentially affecting millions of people living in endemic areas, particularly in Nigeria. Annually, an estimated 300,000 humans are infected and several thousands succumb to the disease. The successful development of the vaccine "Candid#1" against Junin virus, the causative agent of Argentine hemorrhagic fever, proved that an effective arenavirus vaccine can be developed. Although several promising studies toward the development of a Lassa fever vaccine have been published, no vaccine candidate has been tested in human volunteers or patients. This review summarizes the immunology and other aspects of existing experimental arenavirus vaccine studies, discusses the reasons for the lack of a vaccine, and proposes a plan for overcoming the final hurdles toward clinical trials.

Cricotracheal resection for laryngeal invasion by thyroid carcinoma: our experience.

Invasion of the laryngeal framework by thyroid carcinoma requires specific surgical techniques and carries a higher rate of complications that deserve to be highlighted. We reviewed our data from 1995 to 2012 and found six patients with laryngotracheal invasion by thyroid carcinoma. All underwent total thyroidectomy and single-stage cricotracheal resection, plus anterolateral neck dissection. Three had airway obstruction that necessitated prior endoscopic debulking. None of the patients needed a tracheotomy. There were four cases of papillary carcinoma, and two cases of undifferentiated carcinoma. One patient died of complications of the procedure (anastomotic dehiscence and tracheo-innominate artery fistula). Another died 2 months after the procedure from local recurrence and aspiration pneumonia. One case presented recurrence at 15 months, which was managed by re-excision and adjuvant radiotherapy; after 26 months of follow-up, he has no evidence of locoregional recurrence. The three other patients are alive without evidence of disease at 6, 18 and 41 months, respectively. Cricotracheal resection for subglottic invasion by thyroid carcinoma is an effective procedure, but carries significant risks of complications. This could be attributed to the devascularisation of the tracheal wall due to the simultaneous neck dissection, sacrifice of the strap muscles or of a patch of oesophageal muscle layer. We advocate a sternocleidomastoid flap to cover the anastomosis. Cricotracheal resection for subglottic invasion can be curative with good functional outcomes, even for the advanced stages of thyroid cancer. Endoscopic debulking of the airway prior to the procedure avoids tracheotomy.

Population pharmacokinetics of ganciclovir in solid-organ transplant recipients receiving oral valganciclovir.

Valganciclovir (VGC) is an oral prodrug of ganciclovir (GCV) recently introduced for prophylaxis and treatment of cytomegalovirus infection. Optimal concentration exposure for effective and safe VGC therapy would require either reproducible VGC absorption and GCV disposition or dosage adjustment based on therapeutic drug monitoring (TDM). We examined GCV population pharmacokinetics in solid organ transplant recipients receiving oral VGC, including the influence of clinical factors, the magnitude of variability, and its impact on efficacy and tolerability. Nonlinear mixed effect model (NONMEM) analysis was performed on plasma samples from 65 transplant recipients under VGC prophylaxis or treatment. A two-compartment model with first-order absorption appropriately described the data. Systemic clearance was markedly influenced by the glomerular filtration rate (GFR), patient gender, and graft type (clearance/GFR = 1.7 in kidney, 0.9 in heart, and 1.2 in lung and liver recipients) with interpatient and interoccasion variabilities of 26 and 12%, respectively. Body weight and sex influenced central volume of distribution (V(1) = 0.34 liter/kg in males and 0.27 liter/kg in females [20% interpatient variability]). No significant drug interaction was detected. The good prophylactic efficacy and tolerability of VGC precluded the demonstration of any relationship with GCV concentrations. 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 the GCV profile after treatment with oral VGC, routine TDM does not appear to be clinically indicated in solid-organ transplant recipients. However, GCV plasma measurement may still be helpful in specific clinical situations.

The expression and impact of antifungal grooming in ants.

Parasites can cause extensive damage to animal societies in which many related individuals frequently interact. In response, social animals have evolved diverse individual and collective defences. Here, we measured the expression and efficiency of self-grooming and allo-grooming when workers of the ant Formica selysi were contaminated with spores of the fungal entomopathogen Metarhizium anisopliae. The amount of self-grooming increased in the presence of fungal spores, which shows that the ants are able to detect the risk of infection. In contrast, the amount of allo-grooming did not depend on fungal contamination. Workers groomed all nestmate workers that were re-introduced into their groups. The amount of allo-grooming towards noncontaminated individuals was higher when the group had been previously exposed to the pathogen. Allo-grooming decreased the number of fungal spores on the surface of contaminated workers, but did not prevent infection in the conditions tested (high dose of spores and late allo-grooming). The rate of disease transmission to groomers and other nestmates was extremely low. The systematic allo-grooming of all individuals returning to the colony, be they contaminated or not, is probably a simple but robust prophylactic defence preventing the spread of fungal diseases in insect societies.

Comparison of single doses of amoxicillin or of amoxicillin-gentamicin for the prevention of endocarditis caused by Streptococcus faecalis and by viridans streptococci.

Recent recommendations for the prophylaxis of endocarditis in humans have advocated single doses or short courses of antibiotic combinations (beta-lactam plus aminoglycoside) for susceptible patients in whom enterococcal bacteremia might develop or for patients at especially high risk of developing endocarditis (e.g., patients with prosthetic cardiac valves). We tested the prophylactic efficacy (in rats with catheter-induced aortic vegetations) of single doses of amoxicillin plus gentamicin against challenge with various streptococcal strains (two strains of Streptococcus faecalis, one of Streptococcus bovis, and three of viridans streptococci); we then compared this efficacy with that of single doses of amoxicillin alone. Successful prophylaxis against all six strains was achieved with single doses of both amoxicillin alone and amoxicillin plus gentamicin. This protection, however, was limited, for both regimens, to the lowest bacterial-inoculum size producing endocarditis in 90% of control rats and was not extended to higher inocula by using the combination of antibiotics. We concluded that a single dose of amoxicillin alone was protective against enterococcal and nonenterococcal endocarditis in the rat, but that its efficacy was limited and could not be improved by the simultaneous administration of gentamicin.