La convivencia con los cyborgs y los robots: Consideraciones filosóficas, ético-morales y sociopolíticas

In this work, we present the cultural evolution that has allowed to overcome many problems derived from the limitations of the human body. These limitations have been solved by a"cyborization" process that began since early anthropogenesis. Originally, it was envisioned to deal with some diseases, accidents or body malfunctions. Nowadays, augmentations improve common human capabilities; one of the most notable is the increase of brain efficiency by using connections with a computer. A basic social question also addressed is which people will and should have access to these augmentations. Advanced humanoid robots (with human external aspect, artificial intelligence and even emotions) already exist and consequently a number of questions arise. For instance, will robots be considered living organisms? Could they be considered as persons? Will we confer the human status to robots? These questions are discussed. Our conclusions are that the advanced humanoid robots display some actions that may be considered as life-like, yet different to the life associated with living organisms, also, to some extend they could be considered as persons-like, but not humans.

Strategies of "Pseudomonas aeruginosa" to overcome copper limitation

Summary Copper is an important trace element and micronutrient for living organisms as it is the cofactor of several enzymes involved in diverse biological redox processes such as aerobic respiration, denitrification and photosynthesis. Despite its importance, copper may be poorly bioavailable in soils and aquatic environments, as well as in the human body, especially at physiological or alkaline pH. In this work, we have investigated the strategies that the versatile bacterium and opportunistic pathogen Pseudomonas aeruginosa has evolved to face and overcome copper limitation. The global response of the P. aeruginosa to copper limitation was assessed under aerobic conditions. Numerous iron uptake functions (including the siderophores pyoverdine and pyochelin) were down-regulated whereas expression of cioAB (encoding an alternative, copper-independent, cyanide-resistant ubiquinol oxidase) was up-regulated. Wild type P. aeruginosa was able to grow aerobically in a defined glucose medium depleted of copper by a copper chelator, whereas a cioAB mutant did not grow. Thus, P. aeruginosa relies on the CioAB enzyme to cope with severe copper deprivation. A quadruple cyo cco1 cco2 cox mutant, which was deleted for all known heme-copper terminal oxidases of P. aeruginosa, grew aerobically, albeit more slowly than did the wild type, indicating that the CioAB enzyme is capable of energy conservation. However, the expression of a cioA'-'lacZ fusion was less dependent on the copper status in the quadruple mutant than in the wild type, suggesting that copper availability might affect cioAB expression indirectly, via the function of the heme-copper oxidases. These results suggest that the CioAB enzyme can be used as a by-pass strategy to overcome severe copper limitation and perform aerobic respiration even if virtually no copper is available. The PA0114 gene, which encodes a protein of the SCOT/SenC family, was found to be important for copper acquisition and aerobic respiration in low copper conditions. A PA0114 (sent) mutant grew poorly in low copper media and had low terminal oxidase activity with TMPD (N,N,N',N'-tetramethyl-p-phenylenediamine), but expressed the CioAB enzyme at elevated levels. Addition of copper reversed these phenotypes, suggesting that periplasmic copper capture by the SenC protein is another strategy that helps P. aeruginosa to adapt to copper deprivation. RESUME Le cuivre est un micronutriment important pour les organismes vivants. Il représente le cofacteur de plusieurs enzymes impliquées dans une multitude de processus biologiques tels que la respiration aérobie, la dénitrification et la photosynthèse. Malgré son importance, le cuivre peut être peu disponible dans les sols, les environnements aquatiques et le corps humain, spécialement à pH physiologique ou alcalin. Dans ce travail nous avons étudié les stratégies développées par la bactérie pathogène opportuniste Pseudomonas aeruginosa PAO1 afm de faire face et de surmonter le manque de cuivre. La réponse globale de P. aeruginosa à la carence de cuivre a été analysée dans des conditions aérobie. Les résultats obtenus ont montré que plusieurs gènes impliqués dans l'acquisition du fer, tels que les gènes codant pour les sidérophores (pyoverdine et pyochéline), étaient réprimés, tandis que l'expression de l'opéron cioAB, codant pour l'oxydase terminale insensible au cyanure (CIO), était augmentée. La souche sauvage P. aeruginosa est capable de croître dans un milieu où la concentration en cuivre est limitée, due à la présence d'un chélateur spéciftque de cuivre, tandis que le mutant cioAB ne croît pas dans ces conditions. Nous avons conclu que P. aeruginosa nécessite l'oxydase terminale CIO pour faire face à la carence en cuivre. Un quadruple mutant affecté dans toutes les oxydases dépendantes du cuivre (cyo ccol cco2 cox) et appartenant aux oxydases de type hème-cuivre, peut croître en aérobie, néanmoins plus lentement que la souche sauvage, ce qui montre que l'enzyme CIO est capable de conserver l'énergie. L'expression de la fusion rapportrice cioA'-'IacZ chez le quadruple mutant est moins dépendante de la disponibilité de cuivre que chez la souche sauvage. Ces résultats suggèrent que la disponibilité de cuivre influence l'expression de cioAB d'une façon indirecte, par le biais des oxydases terminales de type héme-cuivre. Il est donc possible qu'en cas de carence de cuivre, P. aeruginosa utilise l'enzyme CIO comme stratégie afin de surmonter ce manque et de réaliser la respiration aérobie. Nous avons démontré que le gène PA0114, codant pour une protéine appartenant à la famille SCO1/SenC, est important dans l'acquisition et dans la respiration aérobie dans des environnements où le cuivre est présent en faible concentration. En ces conditions, la croissance du mutant senC est faible; de plus, l'activité des oxydases terminales en présence du donneur d'électrons TMPD (N,N,N,N'-tetraméthyl-p-phénylenediamine) est basse. Toutefois, l'addition de cuivre au milieu de culture permet de restaurer le phénotype du type sauvage. Ces résultats montrent que la protéine SenC est capable d'acquérir le cuivre et représente donc une autre stratégie chez P. aeruginosa pour s'adapter à un manque de cuivre.

Mechanisms of functional T-cell deficiency in melanoma patients

SUMMARYAs a result of evolution, humans are equipped with an intricate but very effective immune system with multiple defense mechanisms primarily providing protection from infections. This system comprises various cell types, including T-lymphocytes, which are able to recognize and directly kill infected cells. T-cells are not only able to recognize cells carrying foreign antigens, such as virus-infected cells, but also autologous cells. In autoimmune diseases, e.g. multiple sclerosis, T- cells attack autologous cells and cause the destruction of healthy tissue. To prevent aberrant immune reactions, but also to prevent damage caused by an overreacting immune response against foreign targets, there are multiple systems in place that attenuate T-cell responses.By contrast, anti-self immune responses may be highly welcome in malignant diseases. It has been demonstrated that activated T-cells are able to recognize and lyse tumor cells, and may even lead to successful cure of cancer patients. Through vaccination, and especially with the help of powerful adjuvants, frequencies of tumor-reactive T-cells can be augmented drastically. However, the efficacy of anti-tumor responses is diminished by the same checks and balances preventing the human body from harm induced by overly activated T-cells in infections.In the context of my thesis, we studied spontaneous and vaccination induced T-cell responses in melanoma patients. The aim of my studies was to identify situations of T-cell suppression, and pinpoint immune suppressive mechanisms triggered by malignant diseases. We applied recently developed techniques such as multiparameter flow cytometry and gene arrays, allowing the characterization of tumor-reactive T-cells directly ex vivo. In our project, we determined functional capabilities, protein expression, and gene expression profiles of small numbers of T- cells from metastatic tissue and blood obtained from healthy donors and melanoma patients. We found evidence that tumor-specific T-cells were functionally efficient effector cells in peripheral blood, but severely exhausted in metastatic tissue. Our molecular screening revealed the upregulation of multiple inhibitory receptors on tumor-specific T-cells, likely implied in T-cell exhaustion. Functional attenuation of tumor-specific T-cells via inhibitory receptors depended on the anatomical location and immune suppressive mechanisms in the tumor microenvironment, which appeared more important than self-tolerance and anergy mechanisms. Our data reveal novel potential targets for cancer therapy, and contribute to the understanding of cancer biology.RÉSUMÉAu cours de l'évolution, les êtres humains se sont vus doter d'un système immunitaire complexe mais très efficace, avec de multiples mécanismes de défense, principalement contre les infections. Ce système comprend différents types de cellules, dont les lymphocytes Τ qui sont capables de reconnaître et de tuer directement des cellules infectées. Les cellules Τ reconnaissent non seulement des cellules infectées par des virus, mais également des cellules autologues. Dans le cas de maladies auto-immunes, comme par exemple la sclérose en plaques, les cellules Τ s'attaquent à des cellules autologues, ce qui engendre la destruction des tissus sains. Il existe plusieurs systèmes de contrôle des réponses Τ afin de minimiser les réactions immunitaires aberrantes et d'empêcher les dégâts causés par une réponse immunitaire trop importante contre une cible étrangère.Dans le cas de maladies malignes en revanche, une réponse auto-immune peut être avantageuse. Il a été démontré que les lymphocytes Τ étaient également capables de reconnaître et de tuer des cellules tumorales, pouvant même mener à la guérison d'un patient cancéreux. La vaccination peut augmenter fortement la fréquence des cellules Τ réagissant contre une tumeur, particulièrement si elle est combinée avec des adjuvants puissants. Cependant, l'efficacité d'une réponse antitumorale est atténuée par ces mêmes mécanismes de contrôle qui protègent le corps humain des dégâts causés par des cellules Τ activées trop fortement pendant une infection.Dans le cadre de ma recherche de thèse, nous avons étudié les réponses Τ spontanées et induites par la vaccination dans des patients atteints du mélanome. Le but était d'identifier des conditions dans lesquelles les réponses des cellules Τ seraient atténuées, voire inhibées, et d'élucider les mécanismes de suppression immunitaire engendrés par le cancer. Par le biais de techniques nouvelles comprenant la cryométrie de flux et l'analyse globale de l'expression génique à partir d'un nombre minimal de cellules, il nous fut possible de caractériser des cellules Τ réactives contre des tumeurs directement ex vivo. Nous avons examiné les profiles d'expression de gènes et de protéines, ainsi que les capacités fonctionnelles des cellules Τ isolées à partir de tissus métastatiques et à partir du sang de patients. Nos résultats indiquent que les cellules Τ spécifiques aux antigènes tumoraux sont fonctionnelles dans le sang, mais qu'elles sont épuisées dans les tissus métastatiques. Nous avons découvert dans les cellules Τ antitumorales une augmentation de l'expression des récepteurs inhibiteurs probablement impliqués dans l'épuisement de ces lymphocytes T. Cette expression particulière de récepteurs inhibiteurs dépendrait donc de leur localisation anatomique et des mécanismes de suppression existant dans l'environnement immédiat de la tumeur. Nos données révèlent ainsi de nouvelles cibles potentielles pour l'immunothérapie du cancer et contribuent à la compréhension biologique du cancer.

Role of the serine protease CAP1/Prss8 and its inhibitor in the skin

The skin is the largest organ of the human body and protects it from water loss and mechanical damage. This barrier function is mainly provided by the epidermis, the outermost layer of the skin. This balance is regulated by several factors, including serine proteases, serine protease inhibitors and protease target substrates, such as receptors. Any mutations or alterations in the expression of these factors can lead to skin diseases. One of the players in this skin balance is the serine protease CAP1/Prss8, whose over-expression causes ichthyosis, hyperplasia and inflammation. This phenotype can be completely restored in the absence of PAR2 (protease-activated receptor 2) (Frateschi et al., 2011). During my thesis, I demonstrated that CAP1/Prss8 induces skin disease even if its catalytic triad is mutated. Additionally, I demonstrated an inhibitory effect of the serine protease-inhibitor nexin-1 (also called serpinE2, PN-1) on CAP1/Prss8, since nexin-1 negated the effects of both catalytically active and inactive CAP1/Prss8 over-expression. Indeed, CAP1/Prss8 and nexin-1 interact in vitro, but independent of the catalytic triad of CAP1/Prss8. These results demonstrate a novel mechanism of interaction between CAP1/Prss8 and nexin-1, and indicate that the catalytic triad of CAP1/Prss8 is dispensable for nexin-1 inhibition and PAR2 activation. These observations in vivo and in vitro could be helpful to specifically target drugs to treat ichthyoses-like skin diseases, like e.g. atopic dermatitis. - La peau est l'un des organes les plus importants du corps humain au regard de sa surface et de sa masse. Ses principales fonctions sont de nous protéger contre l'entrée de pathogènes et de former une barrière imperméable qui empêche la déshydratation. Ces fonctions sont principalement assurées par l'épiderme, la couche la plus superficielle de la peau, et garanties par plusieurs "acteurs", comme par exemple les sérine-protéases, les inhibiteurs de sérine- protéases ou les protéases cibles comme les récepteurs. Toute mutation ou altération de l'un de ces "acteurs" peut aboutir au déclanchement de maladies de la peau. Pour mieux comprendre les conséquences biologiques résultant d'une altération d'expression de CAP1/Prss8, une serine-protéase normalement exprimée au niveau de l'épiderme, nous avons généré des souris transgéniques surexprimant CAP1/Prss8 au niveau de la peau. Ces dernières présentent une peau squameuse, un épiderme hypertrophique, des processus inflammatoires et des prurits conséquents. Ces symptômes disparaissent si le gène du récepteur PAR2, qui régule l'activité des cellules de l'épiderme, est inactivé. Dans le but de vérifier si le phénotype observé chez les souris CAP1/Prss8 résulte de l'action du site catalytique de CAP1/Prss8, nous avons généré des souris CAP1/Prss8 chez lesquelles nous avons muté les trois acides aminés du site catalytique en alanine. Etonnement ces souris ont développé les mêmes problèmes de peau que les souris CAP1/Prss8, démontrant que l'effet de CAP1/Prss8, dans ce modèle animal, n'est pas lié à son site catalytique. Nous avons également montré in vivo, que la sérine-protéase nexin-1 (aussi appelée SERPINE2, PN-1) est capable d'exercer un effet inhibiteur sur CAP1/Prss8 indépendamment de l'activité du site catalytique de CAP1/Prss8. De plus, nous avons remarqué in vitro que CAP1/Prss8 et nexin-1 interagissent bien que la triade catalytique de CAP1/Prss8 soit enzymatiquement inactivée. Ces observations, in vivo et in vitro, pourraient être utilisées dans l'élaboration de médicaments contenant nexin-1, pour le traitement de pathologies de la peau telles l'ichthyose et la dermatite atopique.

Totally implantable robot to treat chronic atrial fibrillation

Chronic atrial fibrillation affects millions of people worldwide. Its surgical treatment often fails to restore the transport function of the atrium. This study first introduces the concept of an atrial assist device (AAD) to restore the pump function of the atrium. The AAD is developed to be totally implantable in the human body with a transcutaneous energy transfer system to recharge the implanted battery. The ADD consists of a motorless pump based on artificial muscle technology, positioned on the external surface of the atrium to compress it and restore its muscular activity. A bench model reproduces the function of a fibrillating atrium to assess the circulatory support that this pump can provide. Atripump (Nanopowers SA, Switzerland) is a dome-shaped silicone-coated nitinol actuator 5 mm high, sutured on the external surface of the atrium. A pacemaker-like control unit drives the actuator that compresses the atrium, providing the mechanical support to the blood circulation. Electrical characteristics: the system is composed of one actuator that needs a minimal tension of 15 V and has a maximum current of 1.5 A with a 50% duty cycle. The implantable rechargeable battery is made of a cell having the following specifications: nominal tension of a cell: 4.1 V, tension after 90% of discharge: 3.5 V, nominal capacity of a cell: 163 mA h. The bench model consists of an open circuit made of latex bladder 60 mm in diameter filled with water. The bladder is connected to a vertically positioned tube that is filled to different levels, reproducing changes in cardiac preload. The Atripump is placed on the outer surface of the bladder. Pressure, volume and temperature changes were recorded. The contraction rate was 1 Hz with a power supply of 12 V, 400 mA for 200 ms. Preload ranged from 15 to 21 cm H(2)O. Maximal silicone membrane temperature was 55 degrees C and maximal temperature of the liquid environment was 35 degrees C. The pump produced a maximal work of 16 x 10(-3) J. Maximal volume pumped was 492 ml min(-1). This artificial muscle pump is compact, follows the Starling law and reproduces the hemodynamic performances of a normal atrium. It could represent a new tool to restore the atrial kick in persistent atrial fibrillation.

The metabolic syndrome, a multifaceted disease of affluence

Metabolic syndrome developed in consequence of an evolutionary inadequacy: the human body was unprepared for a dietary excess of nutrients, especially lipids (largely in detriment of carbohydrate). This excess awakens metabolic signals akin to those of starvation, in which the main energy staple is the body"s own lipid reserve. Lipid dietary abundance prevents the use of glucose, which in turn limits the oxidation of amino acids. To ward against a subsequent avalanche of substrates, the immune system and hypertrophied tissues (for example, adipose) elicit a series of defence responses. This response is probably the ultimate basis of a disease that is manifested as various pathologies, which were initially defined as distinct entities but which are slowly being seen as a single pathognomic unit in the literature. Based on their common origin of the ample availability of food in our modern society, the cluster of diseases comprising the metabolic syndrome is probably best described as a single multifaceted disease.

Mechanisms of interaction of therapeutic nanoparticles with cells

Nanoparticles (NPs) have gained a lot of interest in recent years due to their huge potential for applications in industry and medicine. Their unique properties offer a large number of attractive possibilities in the biomedical field, providing innovative tools for diagnosis of diseases and for novel therapies. Nevertheless, a deep understanding of their interactions with living tissues and the knowledge about their possible effects in the human body are necessary for the safe use of nanoparticulate formulations. The aim of this PhD project was to study in detail the interactions of therapeutic NPs with living cells, including cellular uptake and release, cellular localization and transport across the cell layers. Moreover, the effects of NPs on the cellular metabolic processes were determined using adapted in vitro assays. We evaluated the biological effect of several NPs potentially used in the biomedical field, including titanium dioxide (Ti02) NPs, 2-sized fluorescent silica NPs, ultrasmall superparamagnetic iron oxide (USPIO) NPs, either uncoated or coated with oleic acid or with polyvinylamine (aminoPVA) and poly(lactic-co-glycolic acid) - polyethylene-oxide (PLGA-PEO) NPs. We have found that the NPs were internalized by the cells, depending on their size, chemical composition, surface coating and also depending on the cell line considered. The uptake of aminoPVA-coated USPIO NPs by endothelial cells was enhanced in the presence of an external magnetic field. None of the tested USPIO NPs and silica NPs was transported across confluent kidney cell layers or brain endothelial cell layers, even in the presence of a magnetic field. However, in an original endothelium-glioblastoma barrier model which was developed, uncoated USPIO NPs were directly transferred from endothelial cells to glioblastoma cells. Following uptake, Ti02 NPs and uncoated USPIO NPs were released by the kidney cells, but not by the endothelial cells. Furthermore, these NPs induced an oxidative stress and autophagy in brain endothelial cells, possibly associated with their enhanced agglomeration in cell medium. A significant DNA damage was found in brain endothelial cells after their exposure to TiO2NPs. Altogether these results extend the existing knowledge about the effects of NPs on living cells with regard to their physicochemical characteristics and provide interesting tools for further investigation. The development of the in vitro toxicological assays with a special consideration for risk evaluation aims to reduce the use of animal experiments. -Les nanoparticules (NPs) présentent beaucoup d'intérêt dans le domaine biomédical et industriel. Leurs propriétés uniques offrent un grand nombre de possibilités de solutions innovantes pour le diagnostique et la thérapie. Cependant, pour un usage sûr des NPs il est nécessaire d'acquérir une connaissance approfondie des mécanismes d'interactions des NPs avec les tissus vivants et de leur effets sur le corps humain. Le but de ce projet de thèse était d'étudier en détail les mécanismes d'interactions de NPs thérapeutiques avec des cellules vivantes, en particulier les mécanismes d'internalisation cellulaire et leur subséquente sécrétion par les cellules, leur localisation cellulaire, leur transport à travers des couches cellulaires, et l'évaluation des effets de NPs sur le métabolisme cellulaire, en adaptant les méthodes existante d'évaluation cyto-toxico logique s in vitro. Pour ces expériences, les effets biologiques de nanoparticules d'intérêt thérapeutique, telles que des NPs d'oxyde de titane (TiO2), des NPs fluorescents de silicate de 2 tailles différentes, des NPs, d'oxyde de fer super-para-magnétiques ultra-petites (USPIO), soit non- enrobées soit enrobées d'acide oléique ou de polyvinylamine (aminoPVA), et des NPs d'acide poly(lactique-co-glycolique)-polyethylene-oxide (PLGA-PEO) ont été évalués. Les résultats ont démontré que les NPs sont internalisées par les cellules en fonction de leur taille, composition chimique, enrobage de surface, et également du type de cellules utilisées. L'internalisation cellulaire des USPIO NPs a été augmentée en présence d'un aimant externe. Aucune des NPs de fer et de silicate n'a été transportée à travers des couches de cellules épithéliales du rein ou endothéliales du cerveau, même en présence d'un aimant. Cependant, en développant un modèle original de barrière endothélium-glioblastome, un transfert direct de NPs d'oxyde de fer de cellule endothéliale à cellule de glioblastome a été démontré. A la suite de leur internalisation les NPs d'oxyde de fer et de titane sont relâchées par des cellules épithéliales du rein, mais pas des cellules endothéliales du cerveau. Dans les cellules endothéliales du cerveau ces NPs induisent en fonction de leur état d'agglomération un stress oxydatif et des mécanismes d'autophagie, ainsi que des dommages à l'ADN des cellules exposées aux NPs d'oxyde de titane. En conclusion, les résultats obtenus élargissent les connaissances sur les effets exercés par des NPs sur des cellules vivantes et ont permis de développer les outils expérimentaux pour étudier ces effets in vitro, réduisant ainsi le recours à des expériences sur animaux.

Role of forkhead transcription factor FOXC2 in lymphatic vascular developement

Le système vasculaire lymphatique est le second réseau de vaisseaux du corps humain. Sa fonction principale est de retourner le fluide interstitiel excédentaire au système cardiovasculaire. Il est également impliqué dans la défense immunitaire de l'organisme, ainsi que dans le transport initial des graisses alimentaires. De multiples pathologies sont associées au dysfonctionnement du développement vasculaire lymphatique, dont les lymphoedèmes. Un des gènes clés dans le contrôle de l'étape de maturation du système lymphatique est le facteur de transcription FOXC2. De précédentes études utilisant des modèles génétiques mutins déficients en Foxc2 ont montré son rôle dans la régulation du processus de spécification des vaisseaux lymphatiques en capillaires versus vaisseaux collecteurs, ainsi que dans la formation des valves lymphatiques. Chez l'homme, les mutations dans le gène FOXC2 causent le syndrome lymphoedème- distichiasis. Dans ce travail, nous avons étudié les mécanismes moléculaires qui régulent l'expression et l'activité de FOXC2 dans les vaisseaux lymphatiques. Nous avons découvert que la fonction de FOXC2 est régulée par phosphorylation de la protéine, qui détermine son activité transcriptionnelle au niveau génomique, jouant ainsi un rôle important dans le développement vasculaire in vivo. Les vaisseaux lymphatiques sont soumis à des forces de stress générées par le flux de la lymphe (FSS). Nous avons donc testé l'hypothèse que ces forces contribuent à la morphogenèse et à l'organisation des vaisseaux lymphatiques. In vitro, les cellules endothéliales lymphatiques répondent aux forces mécaniques, qui induisent l'expression de FOXC2, activent la voie de signalisation Ca2+/calcineurin/NFATcl et régulent l'expression de la protéine de jonction gap connexin37. Nous avons également montré que le stress de flux mécanique, FOXC2, calcineurin/NFATcl et connexin37 coopèrent dans le contrôle de la maturation des vaisseaux lymphatiques in vivo. En dernier lieu, nous avons cherché à identifier les récepteurs de surface cellulaires permettant le transfert du signal de stress mécanique qui induit l'expression de FOXC2. Nous présentons ici des données préliminaires, qui suggèrent le rôle de la voie de signalisation TGFß ainsi que l'implication des jonctions adhérentes dans ce processus. En conclusion, la présente étude met en lumière les mécanismes de l'activité de FOXC2 dans les cellules endothéliales lymphatiques et l'importance du rôle des forces mécaniques de flux dans le contrôle de son l'expression, ainsi que dans le développement et la fonction du système vasculaire lymphatique. - The lymphatic vascular system is a second vascular system of human body. Its main fonction is to transfer excess interstitial fluid back to cardiovascular system. In addition, it is involved in immune defense and responsible for the uptake of dietary fat. A number of pathologies called lymphedemas are associated with lymphatic vascular system dysfunction. Hereditary lymphedemas are caused by mutations in genes controlling lymphatic vascular development. One of the key genes responsible for lymphatic vascular maturation is forkhead transcription factor FOXC2. Previous studies of Foxc2 knockout mice showed that Foxc2 controls the process of lymphatic capillary versus collecting vessel fate specification and formation of lymphatic valves. Importantly, mutations in FOXC2 cause human lymphedema-distichiasis syndrome. In this work we investigated the molecular mechanisms regulating the expression and activity of FOXC2 in lymphatic vasculature. We discovered that FOXC2 function is regulated by phosphorylation. We describe how phosphorylation controls FOXC2 transcriptional activity on a genome-wide level and show that FOXC2 phosphorylation plays an important role in vascular development in vivo. Lymphatic vessels are subjected to fluid shear stress (FSS). Therefore we investigated whether mechanical forces contribute to lymphatic vascular patterning and morphogenesis. We found that FSS induces the expression of FOXC2, activates Ca2+/calcineurin/NFATcl signaling and induces the expression of gap junction protein connexin37 in lymphatic endothelial cells in vitro. Importantly, we were able to show that shear stress, FOXC2, calcineurin/NFATcl and connexin37, control maturation of lymphatic vessels in vivo. Finally, we searched for cell surface receptors that mediate the induction of FOXC2 by shear stress, and we present some preliminary data, suggesting the role of TGF-beta signaling and adherens junctions in this process. In conclusion, the present study sheds light on the mechanisms of FOXC2 activity and suggests an important role of mechanical forces in controlling FOXC2 expression as well as lymphatic system development and function.

Postmortem magnetic resonance imaging of the heart ex situ: development of technical protocols.

Postmortem MRI (PMMR) examinations are seldom performed in legal medicine due to long examination times, unfamiliarity with the technique, and high costs. Furthermore, it is difficult to obtain access to an MRI device used for patients in clinical settings to image an entire human body. An alternative is available: ex situ organ examination. To our knowledge, there is no standardized protocol that includes ex situ organ preparation and scanning parameters for postmortem MRI. Thus, our objective was to develop a standard procedure for ex situ heart PMMR examinations. We also tested the oily contrast agent Angiofil® commonly used for PMCT angiography, for its applicability in MRI. We worked with a 3 Tesla MRI device and 32-channel head coils. Twelve porcine hearts were used to test different materials to find the best way to prepare and place organs in the device and to test scanning parameters. For coronary MR angiography, we tested different mixtures of Angiofil® and different injection materials. In a second step, 17 human hearts were examined to test the procedure and its applicability to human organs. We established two standardized protocols: one for preparation of the heart and another for scanning parameters based on experience in clinical practice. The established protocols enabled a standardized technical procedure with comparable radiological images, allowing for easy radiological reading. The performance of coronary MR angiography enabled detailed coronary assessment and revealed the utility of Angiofil® as a contrast agent for PMMR. Our simple, reproducible method for performing heart examinations ex situ yields high quality images and visualization of the coronary arteries.

Biological impact assessment of nanomaterial used in nanomedicine. Introduction to the NanoTEST project.

Therapeutic nanoparticles (NPs) are used in nanomedicine as drug carriers or imaging agents, providing increased selectivity/specificity for diseased tissues. The first NPs in nanomedicine were developed for increasing the efficacy of known drugs displaying dose-limiting toxicity and poor bioavailability and for enhancing disease detection. Nanotechnologies have gained much interest owing to their huge potential for applications in industry and medicine. It is necessary to ensure and control the biocompatibility of the components of therapeutic NPs to guarantee that intrinsic toxicity does not overtake the benefits. In addition to monitoring their toxicity in vitro, in vivo and in silico, it is also necessary to understand their distribution in the human body, their biodegradation and excretion routes and dispersion in the environment. Therefore, a deep understanding of their interactions with living tissues and of their possible effects in the human (and animal) body is required for the safe use of nanoparticulate formulations. Obtaining this information was the main aim of the NanoTEST project, and the goals of the reports collected together in this special issue are to summarise the observations and results obtained by the participating research teams and to provide methodological tools for evaluating the biological impact of NPs.

Potential impact of environmental bacteriophages in spreading antibiotic resistance genes

The idea that bacteriophage transduction plays a role in the horizontal transfer of antibiotic resistance genes is gaining momentum. Such transduction might be vital in horizontal transfer from environmental to human body-associated biomes and here we review many lines of evidence supporting this notion. It is well accepted that bacteriophages are the most abundant entities in most environments, where they have been shown to be quite persistent. This fact, together with the ability of many phages to infect bacteria belonging to different taxa, makes them suitable vehicles for gene transfer. Metagenomic studies confirm that substantial percentages of the bacteriophage particles present in most environments contain bacterial genes, including mobile genetic elements and antibiotic resistance genes. When specific genes of resistance to antibiotics are detected by real-time PCR in the bacteriophage populations of different environments, only tenfold lower numbers of these genes are observed, compared with those found in the corresponding bacterial populations. In addition, the antibiotic resistance genes from these bacteriophages are functional and generate resistance to the bacteria when these genes are transfected. Finally, reports about the transduction of antibiotic resistance genes are on the increase.

El cos molest en l'obra d'Epictet

The work by Epictetus shows a remarkable amount of allusions to unpleasant aspects of the human body. It deals with expressions which sometimes could be almost considered aischrologia and, on other occasions, they really are. Our contribution approaches this subject and asks which might be the origin of this practice. We suggest the use of those expressions describes the body in terms fitting with Epictetus" stoic philosophy aimed to establish an inner separation between body and the right use of reason leading us into virtue. Furthermore his humble origin as a slave could help him in using unpleasant words without prejudices. Also Arrian could insist on that characteristic when transmitting Epictetus" teachings.

Biocerâmicas: tendências e perspectivas de uma área interdisciplinar

The need for new materials to substitute injured or damaged parts of the human body has led scientists of different areas to the investigation of bioceramics since the 70's, when other materials in use started to show implantation problems. Bioceramics show some advantages like being the material that best mimics the bone tissue but also, present low mechanical strength due to its ceramic nature. This paper presents a general view about the topic.

Successful therapies for Alzheimer's disease: why so many in animal models and none in humans?

Peering into the field of Alzheimer's disease (AD), the outsider realizes that many of the therapeutic strategies tested (in animal models) have been successful. One also may notice that there is a deficit in translational research, i.e., to take a successful drug in mice and translate it to the patient. Efforts are still focused on novel projects to expand the therapeutic arsenal to 'cure mice.' Scientific reasons behind so many successful strategies are not obvious. This article aims to review the current approaches to combat AD and to open a debate on common mechanisms of cognitive enhancement and neuroprotection. In short, either the rodent models are not good and should be discontinued, or we should extract the most useful information from those models. An example of a question that may be debated for the advancement in AD therapy is: In addition to reducing amyloid and tau pathologies, would it be necessary to boost synaptic strength and cognition? The debate could provide clues to turn around the current negative output in generating effective drugs for patients. Furthermore, discovery of biomarkers in human body fluids, and a clear distinction between cognitive enhancers and disease modifying strategies, should be instrumental for advancing in anti-AD drug discovery.

Swarm Intelligent Selection and Optimization of Machining System Parameters for Microchannel Fabrication in Medical Devices

Current technology trends in medical device industry calls for fabrication of massive arrays of microfeatures such as microchannels on to nonsilicon material substrates with high accuracy, superior precision, and high throughput. Microchannels are typical features used in medical devices for medication dosing into the human body, analyzing DNA arrays or cell cultures. In this study, the capabilities of machining systems for micro-end milling have been evaluated by conducting experiments, regression modeling, and response surface methodology. In machining experiments by using micromilling, arrays of microchannels are fabricated on aluminium and titanium plates, and the feature size and accuracy (width and depth) and surface roughness are measured. Multicriteria decision making for material and process parameters selection for desired accuracy is investigated by using particle swarm optimization (PSO) method, which is an evolutionary computation method inspired by genetic algorithms (GA). Appropriate regression models are utilized within the PSO and optimum selection of micromilling parameters; microchannel feature accuracy and surface roughness are performed. An analysis for optimal micromachining parameters in decision variable space is also conducted. This study demonstrates the advantages of evolutionary computing algorithms in micromilling decision making and process optimization investigations and can be expanded to other applications