Do opioid receptors play a role in the pathogenesis of the inflammatory response in acute pancreatitis?

PURPOSE: To investigate the effect of the opioid blocker naltrexone in the inflammatory response in acute pancreatitis (AP). METHODS: Acute pancreatitis was induced in anesthetized male Wistar rats by retrograde injection of 2.5% sodium taurocholate diluted in 0.5ml saline into the main pancreatic duct. Animals were randomized to the following experimental groups: Control Group (n=9): animals received an intraperitoneal injection of saline solution (0.5ml), 15 minutes before the induction of AP. Naltrexone Group (n=9): animals received an intraperitoneal injection of naltrexone 0.5ml (15 mg/kg), 15 minutes before induction of AP. Peritoneal levels of TNF-alpha and serum levels of IL-6 and amylase were determined The volume of the ascitic fluid was also evaluated. Myeloperoxidase (MPO) activities were analyzed in homogenates of pulmonary tissue. RESULTS: There were no significant differences in the ascitic fluid volume, nor in TNF-alpha and IL-6 levels in the naltrexone group compared to controls. Treatment with naltrexone did not affect the lung MPO activity compared to control group. CONCLUSIONS: The opioid receptors don't play an important role in the pathogenesis of the inflammatory response in acute pancreatitis. If opioids affect leukocytes inflammatory signaling, there are no major implications in the pathogenesis of acute pancreatitis.

Mistletoes Play Different Roles in a Modular Host-Parasite Network

Antagonistic interactions between host plants and mistletoes often form complex networks of interacting species. Adequate characterization of network organization requires a combination of qualitative and quantitative data. Therefore, we assessed the distribution of interactions between mistletoes and hosts in the Brazilian Pantanal and characterized the network structure in relation to nestedness and modularity. Interactions were highly asymmetric, with mistletoes presenting low host specificity (i.e., weak dependence) and with hosts being highly susceptible to mistletoe-specific infections. We found a non-nested and modular pattern of interactions, wherein each mistletoe species interacted with a particular set of host species. Psittacanthus spp. infected more species and individuals and also caused a high number of infections per individual, whereas the other mistletoes showed a more specialized pattern of infection. For this reason, Psittacanthus spp. were regarded as module hubs while the other mistletoe species showed a peripheral role. We hypothesize that this pattern is primarily the result of different seed dispersal systems. Although all mistletoe species in our study are bird dispersed, the frugivorous assemblage of Psittacanthus spp. is composed of a larger suite of birds, whereas Phoradendron are mainly dispersed by Euphonia species. The larger assemblage of bird species dispersing Psittacanthus seeds may also increase the number of hosts colonized and, consequently, its dominance in the study area. Nevertheless, other restrictions on the interactions among species, such as the differential capacity of mistletoe infections, defense strategies of hosts and habitat types, can also generate or enhance the observed pattern.

Does ragging play a role in medical student depression - Cause or effect?

Background: Medical students experience a lot of stress what may contribute to symptoms of depression. In this study we set out to look at the environmental factors which may be contributing in one medical school in Brazil. Methods: We assessed depressive symptoms using Beck's Depression Inventory in 465 and 267 medical students in 2001 and 2006 respectively. We explored possible social and environmental causes using qualitative data. Results: Nearly 15% scored above the cut off for depression in both the samples. Males in the pre-clinical stage in 2006 showed an increase in depressive symptoms than males in the same cycle in 2001 (aOR = 7.36 [95% CI = 0.85-63.5] p = 0.07). Qualitative data confirmed that factors such as ragging and low social involvement were correlated with depressive symptoms in pre-clinical stage males. Limitations: The sample size was small both for quantitative and qualitative aspects of the study. Conclusions: It appears that ragging plays an important role in the genesis of depressive symptoms in medical students. (C) 2012 Elsevier B.V. All rights reserved.

Tree species richness, does it play a key role on a forest restoration plantation?

The Brazilian Atlantic forest is considered one of the world's biodiversity conservation hotspot. Today there is less than ten percent remaining. Therefore it is necessary to restore these ecosystems. There are many ways of achieving restoration's main goals, but there is a lack of ecological studies that analyzes tree species richness as a variable. Thus, this study's goal is to investigate if there is a difference between a forest restoration in a gradient of tree species richness that varies from 20, 60 to 120 species, by using the litterfall as an indicator. Every month, for one year the forest litter was collected from litter traps that were previously installed. Results revealed that stands produced litterfall by the increasing gradient of species was of 5,370, 5,909 and 6,432 kg ha(-1) yr(-1). The statistical analyses revealed no significant difference among them. Therefore this six-year-old forest restoration plantation shows no difference on the litter production by the tree species richness.

Bracket/wire play: what to expect from tipping prescription on pre-adjusted appliances

INTRODUCTION: The opinion on the 'straight-wire' concept has been evolving since its origin, characterized by faithful followers or absolute skepticism. Currently, it seems reasonable to state that most professionals have a more realistic and critical viewpoint, with an attitude that reveals Orthodontics' maturity and greater knowledge on the technique. The most relevant criticisms refer to the impossibility of the both the Straight-Wire and the Standard systems to completely express the characteristics related to the brackets due to mechanical deficiencies, such as bracket/wire play. OBJECTIVES: A critical analysis of this relationship, which is unclear due to lack of studies, was the scope of this paper. METHODS: The compensatory treatment of two patients, using Capelozza's individualized brackets, works as the scenery for cephalometric evaluation of changes in incisor inclination produced by different dimensions of leveling archwires. RESULTS: The evaluation of these cases showed that, while the introduction of a 0.019 x 0.025-in stainless steel archwire in a 0.022 x 0.030-in slot did not produce significant changes in incisor inclination, the 0.021 x 0.025-in archwire was capable of changing it, mainly in mandibular incisors, and in the opposite direction to the compensation. CONCLUSION: Considering compensatory treatments, even when using an individualized prescription according to the malocclusion, the bracket/wire play seems to be a positive factor for malocclusion correction, without undesirable movements. Therefore, it seems reasonable to admit that, until a bracket system can have absolute individualization, the use of rectangular wires that still have a certain play with the bracket slot is advisable.

Does carbohydrate supplementation enhance tennis match play performance?

Abstract Background Carbohydrate (CHO) ingestion may be an interesting approach to avoid significant decrement to the tennis match performance. The aim of the present investigation was to assess the effects of CHO supplementation on tennis match play performance. Methods Twelve young tennis players (18.0 ± 1.0 years; 176 ± 3.4 cm; 68.0 ± 2.3 kg; body fat: 13.7 ± 2.4%) with national rankings among the top 50 in Brazil agreed to participate in this study, which utilized a randomized, crossover, double blind research design. The experiment was conducted over a 5-day period in which each player completed two simulated tennis matches of a 3-hour duration. The players received either a CHO or a placebo (PLA) drinking solution during simulated tennis matches. Athlete’s performance parameters were determined by filming each match with two video cameras. Each player was individually tracked for the entire duration of the match to measure the following variables: (1) games won; (2) rally duration; (3) strokes per rally; (4) effective playing time (%); (5) aces; (6) double faults; (7) first service in; (8) second service in; (9) first return in and (10) second return in. Results There were no differences between trials in any of the variables analyzed. Conclusions CHO supplementation did not improve tennis match play performance under the present experimental conditions.

Effects of environmental complexity on neurogenesis in the hippocampal dentate gyrus

Introduction. Postnatal neurogenesis in the hippocampal dentate gyrus, can be modulated by numerous determinants, such as hormones, transmitters and stress. Among the factors positively interfering with neurogenesis, the complexity of the environment appears to play a particularly striking role. Adult mice reared in an enriched environment produce more neurons and exhibit better performance in hippocampus-specific learning tasks. While the effects of complex environments on hippocampal neurogenesis are well documented, there is a lack of information on the effects of living under socio-sensory deprivation conditions. Due to the immaturity of rats and mice at birth, studies dealing with the effects of environmental enrichment on hippocampal neurogenesis were carried out in adult animals, i.e. during a period of relatively low rate of neurogenesis. The impact of environment is likely to be more dramatic during the first postnatal weeks, because at this time granule cell production is remarkably higher than at later phases of development. The aim of the present research was to clarify whether and to what extent isolated or enriched rearing conditions affect hippocampal neurogenesis during the early postnatal period, a time window characterized by a high rate of precursor proliferation and to elucidate the mechanisms underlying these effects. The experimental model chosen for this research was the guinea pig, a precocious rodent, which, at 4-5 days of age can be independent from maternal care. Experimental design. Animals were assigned to a standard (control), an isolated, or an enriched environment a few days after birth (P5-P6). On P14-P17 animals received one daily bromodeoxyuridine (BrdU) injection, to label dividing cells, and were sacrificed either on P18, to evaluate cell proliferation or on P45, to evaluate cell survival and differentiation. Methods. Brain sections were processed for BrdU immunhistochemistry, to quantify the new born and surviving cells. The phenotype of the surviving cells was examined by means of confocal microscopy and immunofluorescent double-labeling for BrdU and either a marker of neurons (NeuN) or a marker of astrocytes (GFAP). Apoptotic cell death was examined with the TUNEL method. Serial sections were processed for immunohistochemistry for i) vimentin, a marker of radial glial cells, ii) BDNF (brain-derived neurotrofic factor), a neurotrophin involved in neuron proliferation/survival, iii) PSA-NCAM (the polysialylated form of the neural cell adhesion molecule), a molecule associated with neuronal migration. Total granule cell number in the dentate gyrus was evaluated by stereological methods, in Nissl-stained sections. Results. Effects of isolation. In P18 isolated animals we found a reduced cell proliferation (-35%) compared to controls and a lower expression of BDNF. Though in absolute terms P45 isolated animals had less surviving cells than controls, they showed no differences in survival rate and phenotype percent distribution compared to controls. Evaluation of the absolute number of surviving cells of each phenotype showed that isolated animals had a reduced number of cells with neuronal phenotype than controls. Looking at the location of the new neurons, we found that while in control animals 76% of them had migrated to the granule cell layer, in isolated animals only 55% of the new neurons had reached this layer. Examination of radial glia cells of P18 and P45 animals by vimentin immunohistochemistry showed that in isolated animals radial glia cells were reduced in density and had less and shorter processes. Granule cell count revealed that isolated animals had less granule cells than controls (-32% at P18 and -42% at P45). Effects of enrichment. In P18 enriched animals there was an increase in cell proliferation (+26%) compared to controls and a higher expression of BDNF. Though in both groups there was a decline in the number of BrdU-positive cells by P45, enriched animals had more surviving cells (+63) and a higher survival rate than controls. No differences were found between control and enriched animals in phenotype percent distribution. Evaluation of the absolute number of cells of each phenotype showed that enriched animals had a larger number of cells of each phenotype than controls. Looking at the location of cells of each phenotype we found that enriched animals had more new neurons in the granule cell layer and more astrocytes and cells with undetermined phenotype in the hilus. Enriched animals had a higher expression of PSA-NCAM in the granule cell layer and hilus Vimentin immunohistochemistry showed that in enriched animals radial glia cells were more numerous and had more processes.. Granule cell count revealed that enriched animals had more granule cells than controls (+37% at P18 and +31% at P45). Discussion. Results show that isolation rearing reduces hippocampal cell proliferation but does not affect cell survival, while enriched rearing increases both cell proliferation and cell survival. Changes in the expression of BDNF are likely to contribute to he effects of environment on precursor cell proliferation. The reduction and increase in final number of granule neurons in isolated and enriched animals, respectively, are attributable to the effects of environment on cell proliferation and survival and not to changes in the differentiation program. As radial glia cells play a pivotal role in neuron guidance to the granule cell layer, the reduced number of radial glia cells in isolated animals and the increased number in enriched animals suggests that the size of radial glia population may change dynamically, in order to match changes in neuron production. The high PSA-NCAM expression in enriched animals may concur to favor the survival of the new neurons by facilitating their migration to the granule cell layer. Conclusions. By using a precocious rodent we could demonstrate that isolated/enriched rearing conditions, at a time window during which intense granule cell proliferation takes place, lead to a notable decrease/increase of total granule cell number. The time-course and magnitude of postnatal granule cell production in guinea pigs are more similar to the human and non-human primate condition than in rats and mice. Translation of current data to humans would imply that exposure of children to environments poor/rich of stimuli may have a notably large impact on dentate neurogenesis and, very likely, on hippocampus dependent memory functions.

New polymeric materials for vascular surgery

The dramatic impact that vascular diseases have on human life quality and expectancy nowadays is the reason why both medical and scientific communities put great effort in discovering new and effective ways to fight vascular pathologies. Among the many different treatments, endovascular surgery is a minimally-invasive technique that makes use of X-ray fluoroscopy to obtain real-time images of the patient during interventions. In this context radiopaque biomaterials, i.e. materials able to absorb X-ray radiation, play a fundamental role as they are employed both to enhance visibility of devices during interventions and to protect medical staff and patients from X-ray radiations. Organic-inorganic hybrids are materials that combine characteristics of organic polymers with those of inorganic metal oxides. These materials can be synthesized via the sol-gel process and can be easily applied as thin coatings on different kinds of substrates. Good radiopacity of organic-inorganic hybrids has been recently reported suggesting that these materials might find applications in medical fields where X-ray absorption and visibility is required. The present PhD thesis aimed at developing and characterizing new radiopaque organic-inorganic hybrid materials that can find application in the vascular surgery field as coatings for the improvement of medical devices traceability as well as for the production of X-ray shielding objects and garments. Novel organic-inorganic hybrids based on different polyesters (poly-lactic acid and poly-ε-caprolactone) and polycarbonate (poly-trimethylene carbonate) as the polymeric phase and on titanium oxide as the inorganic phase were synthesized. Study of the phase interactions in these materials allowed to demonstrate that Class II hybrids (where covalent bonds exists between the two phases) can be obtained starting from any kind of polyester or polycarbonate, without the need of polymer pre-functionalization, thanks to the occurrence of transesterification reactions operated by inorganic molecules on ester and carbonate moieties. Polyester based hybrids were successfully coated via dip coating on different kinds of textiles. Coated textiles showed improved radiopacity with respect to the plain fabric while remaining soft to the touch. The hybrid was able to coat single fibers of the yarn rather than coating the yarn as a whole. Openings between yarns were maintained and therefore fabric breathability was preserved. Such coatings are promising for the production of light-weight garments for X-ray protection of medical staff during interventional fluoroscopy, which will help preventing pathologies that stem from chronic X-ray exposure. A means to increase the protection capacity of hybrid-coated fabrics was also investigated and implemented in this thesis. By synthesizing the hybrid in the presence of a suspension of radiopaque tantalum nanoparticles, PDMS-titania hybrid materials with tunable radiopacity were developed and were successfully applied as coatings. A solution for enhancing medical device radiopacity was also successfully investigated. High metal radiopacity was associated with good mechanical and protective properties of organic-inorganic hybrids in the form of a double-layer coating. Tantalum was employed as the constituent of the first layer deposited on sample substrates by means of a sputtering technique. The second layer was composed of a hybrid whose constituents are well-known biocompatible organic and inorganic components, such as the two polymers PCL and PDMS, and titanium oxide, respectively. The metallic layer conferred to the substrate good X-ray visibility. A correlation between radiopacity and coating thickness derived during this study allows to tailor radiopacity simply by controlling the metal layer sputtering deposition time. The applied metal deposition technique also permits easy shaping of the radiopaque layer, allowing production of radiopaque markers for medical devices that can be unambiguously identified by surgeons during implantation and in subsequent radiological investigations. Synthesized PCL-titania and PDMS-titania hybrids strongly adhered to substrates and show good biocompatibility as highlighted by cytotoxicity tests. The PDMS-titania hybrid coating was also characterized by high flexibility that allows it to stand large substrate deformations without detaching nor cracking, thus being suitable for application on flexible medical devices.

Il Modello ad Attori per lo Sviluppo di Applicazioni Web orientate al Cloud: il Framework Play come Caso di Studio

Negli ultimi anni le Web application stanno assumendo un ruolo sempre più importante nella vita di ognuno di noi. Se fino a qualche anno fa eravamo abituati ad utilizzare quasi solamente delle applicazioni “native”, che venivano eseguite completamente all’interno del nostro Personal Computer, oggi invece molti utenti utilizzano i loro vari dispositivi quasi esclusivamente per accedere a delle Web application. Grazie alle applicazioni Web si sono potuti creare i cosiddetti social network come Facebook, che sta avendo un enorme successo in tutto il mondo ed ha rivoluzionato il modo di comunicare di molte persone. Inoltre molte applicazioni più tradizionali come le suite per ufficio, sono state trasformate in applicazioni Web come Google Docs, che aggiungono per esempio la possibilità di far lavorare più persone contemporanemente sullo stesso documento. Le Web applications stanno assumendo quindi un ruolo sempre più importante, e di conseguenza sta diventando fondamentale poter creare delle applicazioni Web in grado di poter competere con le applicazioni native, che siano quindi in grado di svolgere tutti i compiti che sono stati sempre tradizionalmente svolti dai computer. In questa Tesi ci proporremo quindi di analizzare le varie possibilità con le quali poter migliorare le applicazioni Web, sia dal punto di vista delle funzioni che esse possono svolgere, sia dal punto di vista della scalabilità. Dato che le applicazioni Web moderne hanno sempre di più la necessità di poter svolgere calcoli in modo concorrente e distribuito, analizzeremo un modello computazionale che si presta particolarmente per progettare questo tipo di software: il modello ad Attori. Vedremo poi, come caso di studio di framework per la realizzazione di applicazioni Web avanzate, il Play framework: esso si basa sulla piattaforma Akka di programmazione ad Attori, e permette di realizzare in modo semplice applicazioni Web estremamente potenti e scalabili. Dato che le Web application moderne devono avere già dalla nascita certi requisiti di scalabilità e fault tolerance, affronteremo il problema di come realizzare applicazioni Web predisposte per essere eseguite su piattaforme di Cloud Computing. In particolare vedremo come pubblicare una applicazione Web basata sul Play framework sulla piattaforma Heroku, un servizio di Cloud Computing PaaS.

La produzione drammatica dei fratelli Figueroa y Córdoba, con edizione critica di "Mentir y mudarse a un tiempo"

Diego e José de Figueroa y Córdoba furono due fratelli drammaturghi, attivi nella seconda metà del XVII secolo, che praticarono assiduamente la scrittura in collaborazione. Nel tentativo di rivalutare questi autori ingiustamente dimenticati dalla critica odierna, il presente lavoro si propone di offrire uno studio introduttivo alle figure e al teatro dei due fratelli. Nella prima parte, si offre un profilo biografico dei fratelli Figueroa, riunendo le seppur scarse notizie che possediamo sulla loro vita, in modo da inquadrarne le personalità all’interno degli ambienti letterari dell’epoca. Ci si concentra, poi, sul corpus, proponendo una panoramica delle commedie scritte da Diego e José, dando di ciascuna una breve sinossi e un rapido inquadramento all’interno dei generi tipici del teatro aureo, e segnalando gli eventuali problemi di attribuzione. Si accenna, infine, alla collaborazione dei fratelli nella scrittura di molte delle loro commedie, avanzando alcune ipotesi sulla tecnica compositiva. La seconda parte è costituita da un repertorio bibliografico del teatro “maggiore” dei due fratelli, in cui si descrivono analiticamente tutti gli esemplari conosciuti delle comedias dei Figueroa. Ogni descrizione si completa con una lista delle biblioteche in cui l’esemplare è conservato, lista compilata attraverso la consultazione di cataloghi, cartacei e on-line, delle principali biblioteche con fondi di teatro spagnolo del Siglo de Oro. Infine, la terza parte è dedicata all’edizione critica di una delle commedie scritte in collaborazione da Diego e José: Mentir y mudarse a un tiempo, condotta usando come testo base un manoscritto probabilmente autografo. L’edizione si completa di un apparato critico, con analisi dei testimoni, stemma codicum e registro delle varianti. Precede l’edizione uno studio generale introduttivo all’opera.

Die funktionelle Rolle von LRP1 in der tPA-vermittelten Aktivierung von NMDA-Rezeptoren

Das Low Density Lipoprotein Receptor-related Protein 1 (LRP1) scheint neben seiner ursprünglichen Rolle als Lipoproteinrezeptor auch eine fundamentale Rolle bei der Einleitung von Signaltransduktionskaskaden im sich entwickelnden Gehirn zu spielen. Einer seiner Hauptliganden ist die Serinprotease Tissue-type Plasminogen Aktivator (tPA), welche NMDA-Rezeptor-abhängig MAP Kinasenaktivierung induzieren kann. In dieser Studie sollte daher untersucht werden, ob LRP1 und der NMDA Rezeptor in der tPA-vermittelten Signaltransduktion miteinander kooperieren. Es konnte gezeigt werden, dass sowohl LRP1 als auch der NMDA Rezeptor an der tPA-induzierten Erk1/2 Phosphorylierung beteiligt sind, da dieser Effekt mit den spezifischen Inhibitoren RAP, MK-801 und DL-AP5 blockiert werden konnte. Eine weitere Bestätigung der LRP1-Spezifität zeigte sich durch shRNA knock-down Experimente. Calcium Imaging Experimente ergaben, dass die Applikation von tPA sowohl in primären, hippokampalen Neuronen als auch in der neuronalen Zelllinie HT22 zu einem robusten Einstrom von Calcium in die Zelle führte, welcher mit dem NMDA Rezeptor Inhibitor MK-801 und dem LRP1 Inhibitor RAP blockiert werden konnte. RNAi Experimente und Überexpressionsstudien bestätigten die Beteiligung von PSD-95 als intrazelluläres Adapterprotein, welches die beiden Rezeptoren miteinander verbindet. Als Bindungsstelle für PSD-95 konnte mit Hilfe von LRP1 knock-in Mausneuronen die distale NPxY(2) Domäne am LRP1 C-Terminus identifiziert werden. Diese Ergebnisse führten zu der Hypothese eines multimeren tPA-LRP1-NMDA Rezeptor Komplexes, der über die primäre Bindung von tPA an LRP1 aktiviert wird und anschließend das Signal an den NMDA Rezeptor weiterleitet. Somit weisen die Ergebnisse dieser Arbeit auf einen neuen, tPA-vermittelten Mechanismus zur Öffnung von Glutamatrezeptoren hin, der eine funktionelle Kooperation von dem Lipoproteinrezeptor LRP1 mit dem NMDA Rezeptor voraussetzt.

La narrazione spettacolare. Nuove forme dello storytelling: dai testi narrativi al teatro.

Il lavoro di tesi parte da un presupposto di osservazione empirica. Dopo aver rilevato la ricorrenza da parte di registi teatrali del panorama internazionale all’adattamento di testi non drammatici, ma narrativi per la scena, si è deciso di indagare come la natura narrativa dei testi di partenza si adatti, permanga o muti nel passaggio dal medium narrativo a quello spettacolare. La tesi si suddivide in tre parti. Nella parte intitolata “Della metodologia” (un capitolo), viene illustrato il metodo adottato per affrontare l’analisi degli spettacoli teatrali. Facendo riferimento alla disciplina semiotica teatrale, si è definito l’oggetto empirico di studio come testo spettacolare/performance text. La seconda parte della tesi, “Della comparazione dei modelli comunicativi”, (due capitoli), procede nella definizione: 1) dell’elemento teorico da indagare nei testi spettacolari, ovvero, la “narratività”; 2) dei modelli comunicativi della narrazione e dello spettacolo teatrale e delle loro intersezioni o differenze. Nella terza parte della tesi, “Della critica”, (due capitoli), vengono analizzate alcune delle opere del regista Jurij Ljubimov (Russia), Eimuntas Nekrošius (Lituania), Alvis Hermanis (Lettonia). La scelta è ricaduta sulle opere di questi registi in base a una considerazione: 1) culturale: si è deliberatamente circoscritta la sfera di indagine alla produzione teatrale russa e post-sovietica; 2) estetica: è stato osservato che la linea registica inaugurata da Jurij Ljubimov va permeando l’attività registica di registi più giovani come Nekrošius e Hermanis; 3) statistica: Ljubimov, Nekrošius, Hermanis hanno scelto di mettere in scena testi non drammatici con una elevata frequenza. La tesi è corredata da un’ampia appendice iconografica. Per l’analisi dei testi spettacolari si è fatto riferimento alla visione degli spettacoli in presa diretta in Italia e all’estero.