Agonistes de neurotrofines com a teràpia neuroprotectora per la Esclerosi Múltiple

Les neurotrofines son factors tròfics que poden induir la supervivencia, la diferenciació i el creixement de les neurones i aquesta és la principal raó per la qual les estudiem en el context de les malalties neurológiques. Les propietats nombrades son crucials per a la cerca d’efectes funcionals pel que fa a tractaments de malalties neurológiques. Avui en dia. donada la seva activitat neuroprotectora, s’ha intentat l’administració extena de neurotrofines com una terapia per diverses enfermetats cerebrals, pero fins ara han tingut poc o cap resultat donada la inhabilitat d’aquestes molècules per creuar la barrera hematoencefàlica i pels seus efectes secondaris, com ara el dolor neuroilogic. Per això, l’aplicació de petites molècules similars a les neurotrofines es considerada com unapossible sol•lució com un possible tractament neuroprotector amb el cervell com a diana. L’objectiu principal d’aquest projecte és testar l’eficacia d’un compost replicant de la neurotrofina pel tractament de algunes enfermetats neurològiques i per a estudiar el mecanisme d’acció d’aquesta molècula. Els resultats obtinguts fins al moment mostren que hem desenvolupat e identificat un compost replicant de la neurotrofina (G79) que manté la seva capacitat com a factor de creixement nerviós (NGF) en un assaig funcional d’NGF (diferenciació i tests de supervivència). A més a més, hem obtingut una proba de concepte per a la eficacia d’aquest compost com un agent terapèutic en diversos models in vivo e in vitro d’Esclerosi Múltiple, glaucoma, enfermetat de Parkinson y Esclerosi Lateral Amiotrófica. En conclusió, els resultats obtinguts durant aquests dos anys suggereixen que la molècula replicant d’NGF G79 és un bon candidat per a ser desenvolutat com a part d’una estratégica terapeutica la diferenciació neuronal, promou la supervivència, activa la fosforilització de TrkA i TrkB, vies de senyalització específiques de la neurotrofina. Aquesta molècula ademés pot creuar la barrera hematoencefàlica per vies de transport actiu, millora el score clínic en animals infectats per Encefalomielitis Autoinmune Experimental, protegeix les cèlules gangliars retinals en el model in vivo de Glaucoma, promou la supervivència de les cèlules en els models in vitro de l’enfermetat de Parkinson i en ELA. En resum, els nostres resultats sugereixen que les molècules replicants de neurotrofina poden desenvoluparse com part d’una estratègia terapéutica neuroprotectora.

Emotionally negative stimuli can overcome attentional deficits in patients with visuo-spatial hemineglect.

Left unilateral spatial neglect resulting from right brain damage is characterized by loss of awareness for stimuli in the contralesional side of space, despite intact visual pathways. We examined using fMRI whether patients with neglect are more likely to consciously detect in the neglected hemifield, emotionally negative complex scenes rather than visually similar neutral pictures and if so, what neural mechanisms mediate this effect. Photographs of emotional and neutral scenes taken from the IAPS were presented in a divided visual field paradigm. As expected, the detection rate for emotional stimuli presented in the neglected field was higher than for neutral ones. Successful detection of emotional scenes as opposed to neutral stimuli in the left visual field (LVF) produced activations in the parahippocampal and anterior cingulate areas in the right hemisphere. Detection of emotional stimuli presented in the intact right visual field (RVF) activated a distributed network of structures in the left hemisphere, including anterior and posterior cingulate cortex, insula, as well as visual striate and extrastriate areas. LVF-RVF contrasts for emotional stimuli revealed activations in right and left attention related prefrontal areas whereas RVF-LVF comparison showed activations in the posterior cingulate and extrastriate visual cortex in the left hemisphere. An additional analysis contrasting detected vs. undetected emotional LVF stimuli showed involvement of left anterior cingulate, right frontal and extrastriate areas. We hypothesize that beneficial role of emotion in overcoming neglect is achieved by activation of frontal and limbic lobe networks, which provide a privileged access of emotional stimuli to attention by top-down modulation of processing in the higher-order extrastriate visual areas. Our results point to the importance of top-down regulatory role of the frontal attentional systems, which might enhance visual activations and lead to greater salience of emotional stimuli for perceptual awareness.

Pharmacological stimulation of edar signaling in the adult enhances sebaceous gland size and function.

Impaired ectodysplasin A (EDA) receptor (EDAR) signaling affects ectodermally derived structures including teeth, hair follicles, and cutaneous glands. The X-linked hypohidrotic ectodermal dysplasia (XLHED), resulting from EDA deficiency, can be rescued with lifelong benefits in animal models by stimulation of ectodermal appendage development with EDAR agonists. Treatments initiated later in the developmental period restore progressively fewer of the affected structures. It is unknown whether EDAR stimulation in adults with XLHED might have beneficial effects. In adult Eda mutant mice treated for several weeks with agonist anti-EDAR antibodies, we find that sebaceous gland size and function can be restored to wild-type levels. This effect is maintained upon chronic treatment but reverses slowly upon cessation of treatment. Sebaceous glands in all skin regions respond to treatment, although to varying degrees, and this is accompanied in both Eda mutant and wild-type mice by sebum secretion to levels higher than those observed in untreated controls. Edar is expressed at the periphery of the glands, suggesting a direct homeostatic effect of Edar stimulation on the sebaceous gland. Sebaceous gland size and sebum production may serve as biomarkers for EDAR stimulation, and EDAR agonists may improve skin dryness and eczema frequently observed in XLHED.

A positive interaction between inhibitors of protein synthesis and cefepime in the fight against methicillin-resistant Staphylococcus aureus.

Quinupristin-dalfopristin (Q-D) synergizes with cefepime for the treatment of methicillin-resistant Staphylococcus aureus (MRSA). Here, we studied whether the synergism was restricted to MRSA and if it extended to non-beta-lactam cell wall inhibitors or to other inhibitors of protein synthesis. Three MRSA and two methicillin-susceptible S. aureus (MSSA) strains were tested, including an isogenic pair of mecA (-)/mecA (+) S. aureus Newman. The drug interactions were determined by fractional inhibitory concentration (FIC) indices and population analysis profiles. The antibacterial drugs that we used included beta-lactam (cefepime) and non-beta-lactam cell wall inhibitors (D-cycloserine, fosfomycin, vancomycin, teicoplanin), inhibitors of protein synthesis (Q-D, erythromycin, chloramphenicol, tetracycline, linezolid, fusidic acid), and polynucleotide inhibitors (cotrimoxazole, ciprofloxacin). The addition of each protein inhibitor to cefepime was synergistic (FIC ≤ 0.5) or additive (FIC > 0.5 but < 1) against MRSA, but mostly indifferent against MSSA (FIC ≥ 1 but ≤ 4). This segregation was not observed after adding cotrimoxazole or ciprofloxacin to cefepime. Population analysis profiles were performed on plates in the presence of increasing concentrations of the cell wall inhibitors plus 0.25 × minimum inhibitory concentration (MIC) of Q-D. Cefepime combined with Q-D was synergistic against MRSA, but D-cycloserine and glycopeptides were not. Thus, the synergism was specific to beta-lactam antibiotics. Moreover, the synergism was not lost against fem mutants, indicating that it acted at another level. The restriction of the beneficial effect to MRSA suggests that the functionality of penicillin-binding protein 2A (PBP2A) was affected, either directly or indirectly. Further studies are necessary in order to provide a mechanism for this positive interaction.

THE ROLE OF SPINDLES FOR SLEEP: MANIPULATING OSCILLATORY ACTIVITY IN THE THALAMOCORTICAL NETWORK

Modern urban lifestyle encourages the prolongation of wakefulness, leaving less and less time for sleep. Although the exact functions of sleep remain one of the biggest mysteries in neuroscience, the society is well aware of the negative consequences of sleep loss on human physical and mental health and performance. Enhancing sleep's recuperative functions might allow shortening sleep duration while preserving the beneficial effects of sleep. During sleep, brain activity oscillates across a continuum of frequencies. Individual oscillations have been suggested to underlie distinct functions for sleep and cognition. Gaining control about individual oscillations might allow boosting their specific functions. Sleep spindles are 11 - 15 Hz oscillations characteristic for light non-rapid-eye-movement sleep (NREMS) and have been proposed to play a role in memory consolidation and sleep protection against environmental stimuli. The reticular thalamic nucleus (nRt) has been identified as the major pacemaker of spindles. Intrinsic oscillatory burst discharge in nRt neurons, arising from the interplay of low-threshold (T-type) Ca2+ channels (T channels) and small conductance type 2 (SK2) K+ channels (SK2 channels), underlies this pacemaking function. In the present work we investigated the impact of altered nRt bursting on spindle generation during sleep by studying mutant mice for SK2 channels and for CaV3.3 channels, a subtype of T channels. Using in vitro electrophysiology I showed that nRt bursting was abolished in CaV3.3 knock out (CaV3.3 KO) mice. In contrast, in SK2 channel over-expressing (SK2-OE) nRt cells, intrinsic repetitive bursting was prolonged. Compared to wildtype (WT) littermates, altered nRt burst discharge lead to weakened thalamic network oscillations in vitro in CaV3.3 KO mice, while oscillatory activity was prolonged in SK2-OE mice. Sleep electroencephalographic recordings in CaV3.3 KO and SK2-OE mice revealed that reduced or potentiated nRt bursting respectively weakened or prolonged sleep spindle activity at the NREMS - REMS transition. Furthermore, SK2-OE mice showed more consolidated NREMS and increased arousal thresholds, two correlates of good sleep quality. This thesis work suggests that CaV3.3 and SK2 channels may be targeted in order to modulate sleep spindle activity. Furthermore, it proposes a novel function for spindles in NREMS consolidation. Finally, it provides evidence that sleep quality may be improved by promoting spindle activity, thereby supporting the hypothesis that sleep quality can be enhanced by modulating oscillatory activity in the brain. Le style de vie moderne favorise la prolongation de l'éveil, laissant de moins en moins de temps pour le sommeil. Même si le rôle exact du sommeil reste un des plus grands mystères des neurosciences, la société est bien consciente des conséquences négatives que provoque un manque de sommeil, à la fois sur le plan de la santé physique et mentale ainsi qu'au niveau des performances cognitives. Augmenter les fonctions récupératrices du sommeil pourrait permettre de raccourcir la durée du sommeil tout en en conservant les effets bénéfiques. Durant le sommeil, on observe des oscillations à travers un continuum de fréquences. Il a été proposé que chaque oscillation pourrait être à l'origine de fonctions spécifiques pour le sommeil et la cognition. Pouvoir de contrôler les oscillations individuelles permettrait d'augmenter leurs fonctions respectives. Les fuseaux sont des oscillations de 11 à 15 Hz caractéristiques du sommeil à ondes lentes léger et il a été suggéré qu'elles jouent un rôle majeur pour la consolidation de la mémoire ainsi que dans la protection du sommeil contre les stimuli environnementaux. Le nucleus réticulaire du thalamus (nRt) a été identifié en tant que générateur de rythme des fuseaux. Les bouffées oscillatoires intrinsèques des neurones du nRt, provenant de l'interaction de canaux calciques à bas seuil de type T (canaux T) et de canaux potassiques à faible conductance de type 2 (canaux SK2), sont à l'origine de la fonction de générateur de rythme. Dans ce travail, j'ai étudié l'impact de la modulation de bouffées de nRT sur la génération des fuseaux pendant le sommeil en investiguant des souris génétiquement modifiées pour les canaux SK2 et les canaux CaV3.3, un sous-type de canaux T. En utilisant l'électrophysiologie in vitro j'ai démontré que les bouffées du nRT étaient abolies dans les souris knock-out du type CaV3.3 (CaV3.3 KO). D'autre part, dans les cellules nRT sur-exprimant les canaux SK2 (SK2-OE), les bouffées oscillatoires intrinsèques étaient prolongées. Par rapport aux souris wild type, les souris CaV3.3 KO ont montré un affaiblissement des oscillations thalamiques en réponse à un changement des bouffées de nRT, alors que l'activité oscillatoire était prolongée dans les souris SK2-OE. Des enregistrements EEG du sommeil dans des souris de type CaV3.3 KO et SK2-OE ont révélé qu'une réduction ou augmentation des bouffées nRT ont respectivement affaibli ou prolongé l'activité des fuseaux durant les transitions du sommeil à ondes lentes au sommeil paradoxal. De plus, les souris SK2-OE ont montré des signes de consolidation du sommeil à ondes lentes et un seuil augmenté pour le réveil, deux mesures qui corrèlent avec une bonne qualité du sommeil. Le travail de cette thèse propose que les canaux CaV3.3 et SK2 pourrait être ciblés pour moduler l'activité des fuseaux. De plus, je propose une fonction nouvelle pour les fuseaux dans la consolidation du sommeil à ondes lentes. Finalement je suggère que la qualité du sommeil peut être améliorée en promouvant l'activité des fuseaux, soutenant ainsi l'idée que la qualité du sommeil peut être améliorée en modulant l'activité oscillatoire dans le cerveau.

Repeated Double-Poling Sprint Training in Hypoxia by Competitive Cross-country Skiers.

PURPOSE: Repeated-sprint training in hypoxia (RSH) was recently shown to improve repeated-sprint ability (RSA) in cycling. This phenomenon is likely to reflect fiber type-dependent, compensatory vasodilation, and therefore, our hypothesis was that RSH is even more beneficial for activities involving upper body muscles, such as double poling during cross-country skiing. METHODS: In a double-blinded fashion, 17 competitive cross-country skiers performed six sessions of repeated sprints (each consisting of four sets of five 10-s sprints, with 20-s intervals of recovery) either in normoxia (RSN, 300 m; FiO2, 20.9%; n = 8) or normobaric hypoxia (RSH, 3000 m; FiO2, 13.8 %; n = 9). Before (pre) and after (post) training, performance was evaluated with an RSA test (10-s all-out sprints-20-s recovery, until peak power output declined by 30%) and a simulated team sprint (team sprint, 3 × 3-min all-out with 3-min rest) on a double-poling ergometer. Triceps brachii oxygenation was measured by near-infrared spectroscopy. RESULTS: From pretraining to posttraining, peak power output in the RSA was increased (P < 0.01) to the same extent (29% ± 13% vs 26% ± 18%, nonsignificant) in RSH and in RSN whereas the number of sprints performed was enhanced in RSH (10.9 ± 5.2 vs 17.1 ± 6.8, P < 0.01) but not in RSN (11.6 ± 5.3 vs 11.7 ± 4.3, nonsignificant). In addition, the amplitude in total hemoglobin variations during sprints throughout RSA rose more in RSH (P < 0.01). Similarly, the average power output during all team sprints improved by 11% ± 9% in RSH and 15% ± 7% in RSN. CONCLUSIONS: Our findings reveal greater improvement in the performance of repeated double-poling sprints, together with larger variations in the perfusion of upper body muscles in RSH compared with those in RSN.

Cellular and molecular mechanisms underlying the effects of sleep loss on hippocampal synaptic plasticity

SUMMARY : The function of sleep for the organism is one of the most persistent and perplexing questions in biology. Current findings lead to the conclusion that sleep is primarily for the brain. In particular, a role for sleep in cognitive aspects of brain function is supported by behavioral evidence both in humans and animals. However, in spite of remarkable advancement in the understanding of the mechanisms underlying sleep generation and regulation, it has been proven difficult to determine the neurobiological mechanisms underlying the beneficial effect of sleep, and the detrimental impact of sleep loss, on learning and memory processes. In my thesis, I present results that lead to several critical steps forward in the link between sleep and cognitive function. My major result is the molecular identification and physiological analysis of a protein, the NR2A subunit of NMDA receptor (NMDAR), that confers sensitivity to sleep loss to the hippocampus, a brain structure classically involved in mnemonic processes. Specifically, I used a novel behavioral approach to achieve sleep deprivation in adult C57BL6/J mice, yet minimizing the impact of secondary factors associated with the procedure,.such as stress. By using in vitro electrophysiological analysis, I show, for the first time, that sleep loss dramatically affects bidirectional plasticity at CA3 to CA1 synapses in the hippocampus, a well established cellular model of learning and memory. 4-6 hours of sleep loss elevate the modification threshold for bidirectional synaptic plasticity (MT), thereby promoting long-term depression of CA3 to CA 1 synaptic strength after stimulation in the theta frequency range (5 Hz), and rendering long-term potentiation induction.more difficult. Remarkably, 3 hours of recovery sleep, after the deprivation, reset the MT at control values, thus re-establishing the normal proneness of synapses to undergo long-term plastic changes. At the molecular level, these functional changes are paralleled by a change in the NMDAR subunit composition. In particular, the expression of the NR2A subunit protein of NMDAR at CA3 to CA1 synapses is selectively and rapidly increased by sleep deprivation, whereas recovery sleep reset NR2A synaptic content to control levels. By using an array of genetic, pharmacological and computational approaches, I demonstrate here an obligatory role for NR2A-containing NMDARs in conveying the effect of sleep loss on CA3 to CAl MT. Moreover, I show that a genetic deletion of the NR2A subunit fully preserves hippocampal plasticity from the impact of sleep loss, whereas it does not alter sleepwake behavior and homeostatic response to sleep deprivation. As to the mechanism underlying the effects of the NR2A subunit on hippocampal synaptic plasticity, I show that the increased NR2A expression after sleep loss distinctly affects the contribution of synaptic and more slowly recruited NMDAR pools activated during plasticity-induction protocols. This study represents a major step forward in understanding the mechanistic basis underlying sleep's role for the brain. By showing that sleep and sleep loss affect neuronal plasticity by regulating the expression and function of a synaptic neurotransmitter receptor, I propose that an important aspect of sleep function could consist in maintaining and regulating protein redistribution and ion channel trafficking at central synapses. These findings provide a novel starting point for investigations into the connections between sleep and learning, and they may open novel ways for pharmacological control over hippocampal .function during periods of sleep restriction. RÉSUMÉ DU PROJET La fonction du sommeil pour l'organisme est une des questions les plus persistantes et difficiles dans la biologie. Les découvertes actuelles mènent à la conclusion que le sommeil est essentiel pour le cerveau. En particulier, le rôle du sommeil dans les aspects cognitifs est soutenu par des études comportementales tant chez les humains que chez les animaux. Cependant, malgré l'avancement remarquable dans la compréhension des mécanismes sous-tendant la génération et la régulation du sommeil, les mécanismes neurobiologiques qui pourraient expliquer l'effet favorable du sommeil sur l'apprentissage et la mémoire ne sont pas encore clairs. Dans ma thèse, je présente des résultats qui aident à clarifier le lien entre le sommeil et la fonction cognitive. Mon résultat le plus significatif est l'identification moléculaire et l'analyse physiologique d'une protéine, la sous-unité NR2A du récepteur NMDA, qui rend l'hippocampe sensible à la perte de sommeil. Dans cette étude, nous avons utilisé une nouvelle approche expérimentale qui nous a permis d'induire une privation de sommeil chez les souris C57BL6/J adultes, en minimisant l'impact de facteurs confondants comme, par exemple, le stress. En utilisant les techniques de l'électrophysiologie in vitro, j'ai démontré, pour la première fois, que la perte de sommeil est responsable d'affecter radicalement la plasticité bidirectionnelle au niveau des synapses CA3-CA1 de l'hippocampe. Cela correspond à un mécanisme cellulaire de l'apprentissage et de la mémoire bien établi. En particulier, 4-6 heures de privation de sommeil élèvent le seuil de modification pour la plasticité synaptique bidirectionnelle (SM). Comme conséquence, la dépression à long terme de la transmission synaptique est induite par la stimulation des fibres afférentes dans la bande de fréquences thêta (5 Hz), alors que la potentialisation à long terme devient plus difficile. D'autre part, 3 heures de sommeil de récupération sont suffisant pour rétablir le SM aux valeurs contrôles. Au niveau moléculaire, les changements de la plasticité synaptiques sont associés à une altération de la composition du récepteur NMDA. En particulier, l'expression synaptique de la protéine NR2A du récepteur NMDA est rapidement augmentée de manière sélective par la privation de sommeil, alors que le sommeil de récupération rétablit l'expression de la protéine au niveau contrôle. En utilisant des approches génétiques, pharmacologiques et computationnelles, j'ai démontré que les récepteurs NMDA qui expriment la sous-unité NR2A sont responsables de l'effet de la privation de sommeil sur le SM. De plus, nous avons prouvé qu'une délétion génétique de la sous-unité NR2A préserve complètement la plasticité synaptique hippocampale de l'impact de la perte de sommeil, alors que cette manipulation ne change pas les mécanismes de régulation homéostatique du sommeil. En ce qui concerne les mécanismes, j'ai .découvert que l'augmentation de l'expression de la sous-unité NR2A au niveau synaptique modifie les propriétés de la réponse du récepteur NMDA aux protocoles de stimulations utilisés pour induire la plasticité. Cette étude représente un pas en avant important dans la compréhension de la base mécaniste sous-tendant le rôle du sommeil pour le cerveau. En montrant que le sommeil et la perte de sommeil affectent la plasticité neuronale en régulant l'expression et la fonction d'un récepteur de la neurotransmission, je propose qu'un aspect important de la fonction du sommeil puisse être finalisé au règlement de la redistribution des protéines et du tracking des récepteurs aux synapses centraux. Ces découvertes fournissent un point de départ pour mieux comprendre les liens entre le sommeil et l'apprentissage, et d'ailleurs, ils peuvent ouvrir des voies pour des traitements pharmacologiques dans le .but de préserver la fonction hippocampale pendant les périodes de restriction de sommeil.

Passive smoking in babies: The BIBE Study (Brief Intervention in babies. Effectiveness)

Background: There is evidence that exposure to passive smoking in general, and in babies in particular, is an important cause of morbimortality. Passive smoking is related to an increased risk of pediatric diseases such as sudden death syndrome, acute respiratory diseases, worsening of asthma, acute-chronic middle ear disease and slowing of lung growth.The objective of this article is to describe the BIBE study protocol. The BIBE study aims to determine the effectiveness of a brief intervention within the context of Primary Care, directed to mothers and fathers that smoke, in order to reduce the exposure of babies to passive smoking (ETS).Methods/DesignCluster randomized field trial (control and intervention group), multicentric and open. Subject: Fathers and/or mothers who are smokers and their babies (under 18 months) that attend pediatric services in Primary Care in Catalonia.The measurements will be taken at three points in time, in each of the fathers and/or mothers who respond to a questionnaire regarding their baby's clinical background and characteristics of the baby's exposure, together with variables related to the parents' tobacco consumption. A hair sample of the baby will be taken at the beginning of the study and at six months after the initial visit (biological determination of nicotine). The intervention group will apply a brief intervention in passive smoking after specific training and the control group will apply the habitual care.Discussion: Exposure to ETS is an avoidable factor related to infant morbimortality. Interventions to reduce exposure to ETS in babies are potentially beneficial for their health. The BIBE study evaluates an intervention to reduce exposure to ETS that takes advantage of pediatric visits. Interventions in the form of advice, conducted by pediatric professionals, are an excellent opportunity for prevention and protection of infants against the harmful effects of ETS.

Lifespan extension by calorie restriction relies on the Sty1 MAP kinase stress pathway

Either calorie restriction, loss of function of the nutrient-dependent PKA or TOR/SCH9 pathways, or activation of stress defences improves longevity in different eukaryotes. However, the molecular links between glucose depletion, nutrient-dependent pathways and stress responses are unknown. Here we show that either calorie restriction or inactivation of nutrient-dependent pathways induces life-span extension in fission yeast, and that such effect is dependent on the activation of the stress-dependent Sty1 MAP kinase. During transition to stationary phase in glucose-limiting conditions, Sty1 becomes activated and triggers a transcriptional stress program, whereas such activation does not occur under glucose-rich conditions. Deletion of the genes coding for the SCH9-homologue Sck2 or the Pka1 kinases, or mutations leading to constitutive activation of the Sty1 stress pathway increase life span under glucose-rich conditions, and importantly such beneficial effects depend ultimately on Sty1. Furthermore, cells lacking Pka1 display enhanced oxygen consumption and Sty1 activation under glucose-rich conditions. We conclude that calorie restriction favours oxidative metabolism, reactive oxygen species production and Sty1 MAP kinase activation, and this stress pathway favours life-span extension.

Protein delivery for retinal diseases: from basic considerations to clinical applications.

Because the eye is protected by ocular barriers but is also easily accessible, direct intravitreous injections of therapeutic proteins allow for specific and targeted treatment of retinal diseases. Low doses of proteins are required in this confined environment and a long time of residency in the vitreous is expected, making the eye the ideal organ for local proteic therapies. Monthly intravitreous injection of Ranibizumab, an anti-VEGF Fab has become the standard of care for patients presenting wet AMD. It has brought the proof of concept that administering proteins into the physiologically low proteic concentration vitreous can be performed safely. Other antibodies, Fab, peptides and growth factors have been shown to exert beneficial effects on animal models when administered within the therapeutic and safe window. To extend the use of such biomolecules in the ophthalmology practice, optimization of treatment regimens and efficacy is required. Basic knowledge remains to be increased on how different proteins/peptides penetrate into the eye and the ocular tissues, distribute in the vitreous, penetrate into the retinal layers and/or cells, are eliminated from the eye or metabolized. This should serve as a basis for designing novel drug delivery systems. The later should be non-or minimally invasive and should allow for a controlled, scalable and sustained release of the therapeutic proteins in the ocular media. This paper reviews the actual knowledge regarding protein delivery for eye diseases and describes novel non-viral gene therapy technologies particularly adapted for this purpose.

Dual role of the antioxidant enzyme peroxiredoxin 6 in skin carcinogenesis.

The antioxidant enzyme peroxiredoxin 6 (Prdx6) is a key regulator of the cellular redox balance, particularly under stress conditions. We identified Prdx6 as an important player in different phases of skin carcinogenesis. Loss of Prdx6 in mice enhanced the susceptibility to skin tumorigenesis, whereas overexpression of Prdx6 in keratinocytes of transgenic mice had the opposite effect. The tumor-preventive effect of Prdx6, which was observed in a human papilloma virus 8-induced and a chemically induced tumor model, was not due to alterations in keratinocyte proliferation, apoptosis, or in the inflammatory response. Rather, endogenous and overexpressed Prdx6 reduced oxidative stress as reflected by the lower levels of oxidized phospholipids in the protumorigenic skin of Prdx6 transgenic mice and the higher levels in Prdx6-knockout mice than in control animals. In contrast to its beneficial effect in tumor prevention, overexpression of Prdx6 led to an acceleration of malignant progression of existing tumors, revealing a dual function of this enzyme in the pathogenesis of skin cancer. Finally, we found strong expression of PRDX6 in keratinocytes of normal human skin and in the tumor cells of squamous cell carcinomas, indicating a role of Prdx6 in human skin carcinogenesis. Taken together, our data point to the potential usefulness of Prdx6 activators or inhibitors for controlling different stages of skin carcinogenesis.

Molecular taxonomy of the Formica rufa group (red wood ants) (Hymenoptera: Formicidae): a new cryptic species in the Swiss Alps?

Because of their beneficial impact on forest ecosystems, European red wood ants (Formica rufa group) are protected by law in many European countries and are considered to be among the most reliable bioindicators of forest stability. However, their taxonomy has been much debated and, unfortunately, it is too often neglected. This happens mainly because the morphology-based method for species delimitation requires lots of time and experience. We therefore employed 9 microsatellite loci and mitochondrial DNA (COI gene) to verify the power of genetic markers for red wood ant species delimitation and to investigate the cryptic diversity of these ants within the Eastern Swiss Alps. We analyzed 83 nests belonging to all red wood ant species that occur in the Swiss National Park area. Genetic data indicated that these species represent different genetic pools. Moreover, results showed that Formica aquilonia YARROW, 1955 and F. paralugubris SEIFERT, 1996 often hybridize within the Park, confirming that these two species are genetically very close and could have diverged only recently. Nevertheless, microsatellites also revealed that one entire population, located in the Minger Valley and morphologically identified as F. lugubris ZETTERSTEDT, 1838, is genetically different to all other analyzed F. lugubris populations found within the same area and to other red wood ant species. These findings, confirmed by mitochondrial DNA analyses, suggest the existence of a new cryptic species within the Eastern Swiss Alps. This putative cryptic species has been provisionally named F. lugubris-A2. These results have a great importance for future conservation plans, monitoring and evolutionary studies on these protected ants.

Development of the Iowa Drainage Law Manual, March 2005

Although Iowa has some of the most productive agricultural land in the nation, it also maintains a very extensive road network.Consequently, landowners and roadway officials often must deal with drainage issues affecting private lands and public highways. However, many individuals are unfamiliar with legal drainage requirements, practices, and procedures, which can result in misunderstandings concerning maintenance responsibilities for drainage facilities, sometimes leading to litigation. To assist propertyowners, public agencies, and others with interest in better understanding drainage maintenance responsibilities, a reference manual was developed to describe Iowa’s drainage laws and offer interpretations in a clear and concise manner. To develop a comprehensive drainage manual, researchers identified and reviewed current available literature. These resources described pertinent drainage issues and presented explanations of legal responsibilities. The literature review included manuals and guides from Iowa, surrounding states, and federal agencies. Researchers developed a survey to assess the needs and interestsof potential users of an Iowa drainage law manual. Survey responses were used to identify common problems and concerns among individuals who encounter drainage issues on a regular basis. Issues mentioned in the survey responses included interpretation of drainage laws and commonly encountered questions relating to public improvements and private interests. Many individuals, including county engineers, stated interest in specific topics such as maintenance and/or diversion of drainage, landowner issues, and upstream and downstream impacts. Overall, the survey provided researchers with valuable information regarding drainage issues, problems, current policies, and concerns. A comprehensive manual of Iowa drainage law will assist agencies and individuals in interpreting current code requirements and in implementing effective and beneficial solutions when dealing with drainage issues.

Tigecycline in combination with other antimicrobials: a review of in vitro, animal and case report studies.

Tigecycline has been investigated in combination with other antibacterials against a wide range of susceptible and multiresistant Gram-positive and Gram-negative bacteria. Combinations have been analysed in vitro, in animal models and in human case reports. In vitro, tigecycline combined with other antimicrobials produces primarily an indifferent response (neither synergy nor antagonism). Nevertheless, synergy occurred when tigecycline was combined with rifampicin against 64-100% of Enterococcus spp., Streptococcus pneumoniae, Enterobacter spp. and Brucella melitensis isolates. Combinations of tigecycline with amikacin also showed synergy for 40-100% of Enterobacter spp., Klebsiella pneumoniae, Proteus spp. and Stenotrophomonas maltophilia isolates. Moreover, bactericidal synergisms occurred with tigecycline plus amikacin against problematic Acinetobacter baumannii and Proteus vulgaris, and with colistin against K. pneumoniae. Data from animal experiments and case reports, although limited, displayed consistent beneficial activity of tigecycline in combination with other antibacterials against multiresistant organisms, including vancomycin against penicillin-resistant S. pneumoniae in experimental meningitis, gentamicin against Pseudomonas aeruginosa in experimental pneumonia, daptomycin against Enterococcus faecium endocarditis, and colistin against K. pneumoniae bacteraemia and P. aeruginosa osteomyelitis. Antagonism was extremely rare in vitro and was not reported in vivo. Thus, tigecycline may be combined with a second antimicrobial as part of a combination regimen.

Deferred effects of nursery school on adolescents' school performance in Spain

This research analysis the long-term effects of nursery school attendance before the age of three in Spain. The effects are measured when the individuals are adolescents and attend secondary school. The article deals with the controversy over the long-term effects of nursery school attendance and its potential effect on reducing inequalities and social exclusion. The results estimate a significant long-term effect of nursery school attendance on improving educational performance, although the beneficial effects are lower among adolescents residing in the lower status households.