534 resultados para Gâmetas de dador - Gamete donation
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The objectives of this study were to evaluate the effect of low-level laser irradiation (LLLI) on bovine oocyte and granulosa cells metabolism during in vitro maturation (IVM) and further embryo development. Cumulus-oocytes complexes (COCs) were subjected (experimental group) or not (control group) to irradiation with LLLI in a 633-nm wavelength and 1 J/cm2 fluency. The COCs were evaluated after 30 min, 8, 16, and 24 h of IVM. Cumulus cells were evaluated for cell cycle status, mitochondrial activity, and viability (flow cytometry). Oocytes were assessed for meiotic progression status (nuclear staining), cell cycle genes content [real-time polymerase chain reaction (PCR)], and signal transduction status (western blot). The COCs were also in vitro fertilized, and the cleavage and blastocyst rates were assessed. Comparisons among groups were statistically performed with 5% significance level. For cumulus cells, a significant increase in mitochondrial membrane potential and the number of cells progressing through the cycle could be observed. Significant increases on cyclin B and cyclin-dependent kinase (CDK4) levels were also observed. Concerning the oocytes, a significantly higher amount of total mitogen-activated protein kinase was found after 8 h of irradiation, followed by a decrease in all cell cycle genes transcripts, exception made for the CDK4. However, no differences were observed in meiotic progression or embryo production. In conclusion, LLLI is an efficient tool to modulate the granulosa cells and oocyte metabolism
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Using x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES) and x-ray photoelectron spectroscopy (XPS) in combination with density functional theory (DFT) the changes in electronic and geometric structure of hydrocarbons upon adsorption are determined. The chemical bonding is analyzed and the results provide new insights in the mechanisms responsible for dehydrogenation in heterogeneous catalysis. In the case of alkanes, n-octane and methane are studied. XAS and XES show significant changes in the electronic structure upon adsorption. XES shows new adsorption induced occupied states and XAS shows quenching of CH*/Rydberg states in n-octane. In methane the symmetry forbidden gas phase lowest unoccupied molecular orbital becomes allowed due to broken symmetry. New adsorption induced unoccupied features with mainly metal character appear just above the Fermi level in XA spectra of both adsorbed methane and n-octane. These changes are not observed in DFT total energy geometry optimizations. Comparison between experimental and computed spectra for different adsorbate geometries reveals that the molecular structures are significantly changed in both molecules. The C-C bonds in n-octane are shortened upon adsorption and the C-H bonds are elongated in both n-octane and methane. In addition ethylene and acetylene are studied as model systems for unsaturated hydrocarbons. The validity of both the Dewar-Chatt-Duncanson chemisorption model and the alternative spin-uncoupling picture is confirmed, as well as C-C bond elongation and upward bending of the C-H bonds. The bonding of ethylene to Cu(110) and Ni(110) are compared and the results show that the main difference is the amount of back-donation into the molecular π* orbital, which allows the molecule to desorb molecularly from the Cu(110) surface, whereas it is dehydrogenated upon heating on the Ni(110) surface. Acetylene is found to adsorb in two different adsorption sites on the Cu(110) surface at liquid nitrogen temperature. Upon heating the molecules move into one of these sites due to attractive adsorbate-adsorbate interaction and only one adsorbed species is present at room temperature, at which point the molecules start reacting to form benzene. The bonding of the two species is very similar in both sites and the carbon atoms are rehybridized essentially to sp2.
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On the basis of illustrations of Shakespeare's Hamlet, the new digital 'Oppel-Hammerschmidt Shakespeare Illustration Archive' at the Mainz University Library - together with a lavishly-constructed and multiply-linked Web interface version - was presented to the public on 17 November 2008. This e-book, edited by Andreas Anderhub and Hildegard Hammerschmidt-Hummel, contains the speeches and presentations given on the occasion of the opening ceremony of the electronic archive. The collection of the new archive, published here for the first time, holds about 3,500 images and is part of the only Shakespeare illustration archive in the world. The Shakespeare Illustration Archive was founded in 1946 by the internationally acclaimed Shakespeare and Goethe scholar, Prof. Horst Oppel. This part of the archive was donated to the Mainz University Library on condition that its holdings be digitalised and made available to the public. The collection has been named 'The Oppel-Hammerschmidt Shakespeare Illustration Archive' in accordance with the terms of the Agreement of Donation of 9, 15, and 16 September 2005, and honouring the 16 March 1988 Delegation of Authority and Declaration of Intent by Frau Ingeborg Oppel, Prof. Oppel's widow and legal assignee. Vice-President Prof. Jürgen Oldenstein opened the proceedings by noting that 2008 had been a good year for international Shakespeare scholarship. For, in London, the site of the 'Theatre' in Shoreditch, where Shakespeare's company performed, had been unearthed, and in Mainz the Shakespeare Archive had gone online with thousands of illustrations. The Dean of the Faculty of Philosophy and Philology, Prof. Mechthild Dreyer, who mentioned that she herself had long been successfully employing interdisciplinary research methods, took particular pleasure in the transdisciplinary approach to research resolutely pursued by Prof. Hammerschmidt-Hummel. Prof. Clemens Zintzen (Cologne), former President of the Mainz Academy of Literature and Sciences, recalled highlights from the more than sixty-year-long history of the Shakespeare Illustration Archive. Prof. Kurt Otten (Heidelberg and Cambridge) drew an impressive portrait of Horst Oppel's personality as an academic and praised his influential books on Goethe and Shakespeare. He pointed out that Oppel's Shakespeare Illustration Archive, the basis for many a dissertation, had enjoyed great popularity around the world. Prof. Otten also delineated the academic career of Prof. Hammerschmidt-Hummel and her new findings regarding Shakespeare's time, life and work. Prof. Rüdiger Ahrens OBE (Würzburg) drew attention to Prof. Hammerschmidt-Hummel's research results, directly or indirectly arising out of her work on the Shakespeare Illustration Archive. This research had centred on proving the authenticity of four visual representations of Shakespeare (the Chandos and Flower portraits, the Davenant bust and the Darmstadt Shakespeare death mask); solving the mystery around Shakespeare's 'Dark Lady'; and establishing the dramatist's Catholic religion. Prof. Hammerschmidt-Hummel reported on her 'Shakespeare Illustration' project, describing the nature, dimensions and significance of the Archive's pictorial material, which relates to all of Shakespeare's plays and stretches over five centuries. She explained that the digital 'Oppel-Hammerschmidt Illustration Archive' was an addition to the three-volume edition she had compiled, authored and edited for publication in 2003. Unlike the print version, however, the digital collection had only been partly editorially prepared. It represented source material and a basis for further work. Hammerschmidt-Hummel expressed her thanks to the Head of the Central University Library, Dr Andreas Anderhub, for his untiring commitment. After the initial donation had been made, he had entered enthusiastically into setting up the necessary contacts, getting all the work underway, and clearing the legal hurdles. Hammerschmidt-Hummel was especially grateful to University of Mainz librarian Heike Geisel, who had worked for nearly five years to carry out the large-scale digitalization of a total of 8,800 items. Frau Geisel was also extremely resourceful in devising ways of making the collection yield even more, e.g. by classifying and cross-linking the data, assembling clusters of individual topics that lend themselves to research, and (in collaboration with the art historian Dr Klaus Weber) making the archive's index of artists compatible with the data-bank of artists held by the University of Mainz Institute of Art History. In addition, she compiled an extremely helpful 'users' guide' to the new digital collection. Frau Geisel had enjoyed invaluable support from Dr Annette Holzapfel-Pschorn, the leading academic in the Central IT Department at the University, who set up an intelligent, most impressive Web interface using the latest application technologies. Frau Geisel and Dr Holzapfel-Pschorn were highly praised for their convincing demonstration, using illustrations to Hamlet, of how to access this well-devised and exceptionally user-friendly Web version. For legal reasons, Prof. Hammerschmidt-Hummel pointed out, the collection could not be released for open access on the internet. The media - as Dr Anderhub stressed in his foreword - had shown great interest in the new digital collection of thousands of Shakespearean illustrations (cf. Benjamin Cor's TV feature in "Tagesthemen", 17 November 2008, presented by Tom Buhrow). The ‘Oppel-Hammerschmidt Shakespeare Illustration Archive’ should also meet with particular interest not only among academic specialists, but also among the performers of the arts and persons active in the cultural realm in general, as well as theatre and film directors, literary managers, teachers, and countless Shakespeare enthusiasts.
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La tesi di dottorato "Unione Europea e Sanità" è uno studio sistematico del diritto alla salute e della protezione della sanità pubblica nell'ordinamento giuridico dell'Unione Europea. Il primo capitolo analizza le competenze sanitarie dell'Unione Europea, introdotte per la prima volta dal Trattato di Maastricht e definitivamente sistemate all'art. 168 TFUE. La norma identifica alcuni settori specifici nei quali l'Unione può agire e altri, quali l'organizzazione dei sistemi sanitari e la fornitura di cure mediche, che rimangono in capo agli Stati membri. Il secondo capitolo esamina le deroghe e le esigenze imperative connesse alla salvaguardia della salute nel mercato interno ed è suddiviso in tre sezioni dedicate alla libera circolazione delle merci, al diritto di stabilimento e alla libera prestazione dei servizi. Nella prima ci si è occupati dello sviluppo della legislazione farmaceutica. Nella seconda si sono analizzati il mutuo riconoscimento delle qualifiche professionali e le legislazioni statali che restringono il diritto di stabilimento degli operatori sanitari transfrontalieri. Nella terza si è rivolta l'attenzione alla mobilità dei pazienti che, attraverso la giurisprudenza della Corte di Giustizia, è stata trasfusa in un atto di diritto derivato. Il terzo capitolo si concentra sul ruolo del diritto alla salute nell'ordinamento giuridico dell'Unione Europea in considerazione del valore vincolante della Carta dei diritti fondamentali. Coerentemente, si è scelto di mantenere una struttura tripartita. Nella prima sezione, ci si interroga sull'esistenza di tale diritto alla luce dei pochi casi presenti. Nella seconda, lo si analizza per il tramite delle obbligazioni di proteggere, rispettare ed adempiere, enucleate attraverso alcuni strumenti internazionali e si verifica il ruolo del principio di non discriminazione in relazione all'accesso alle cure. Nella terza, infine, si verifica il ruolo del consenso informato rispetto alla sperimentazione clinica ed alla donazione di materiale biologico.
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Approximately 25% of acute myeloid leukemias (AMLs) carry internal tandem duplications (ITD) of various lengths within the gene encoding the FMS-like tyrosine kinase receptor 3 (FLT3). Although varying duplication sites exist, most of these length mutations affect the protein´s juxtamembrane domain. FLT3-ITDs support leukemic transformation by constitutive phosphorylation resulting in uncontrolled activation, and their presence is associated with worse prognosis. As known form previous work, they represent leukemia- and patient-specific neoantigens that can be recognized by autologous AML-reactive CD8+ T cells (Graf et al., 2007; Graf et al., unpublished). Herein, in patient FL, diagnosed with FLT3-ITD+ AML and in first complete remission after induction chemotherapy, T cells against her leukemia´s individual FLT3-ITD were detected at a frequency up to 1.7x10-3 among peripheral blood CD8+ T lymphocytes. This rather high frequency suggested, that FLT3-ITD-reactive T cells had been expanded in vivo due to the induction of an anti-leukemia response.rnrnCell material from AML patients is limited, and the patients´ anti-leukemia T-cell repertoire might be skewed, e.g. due to complex previous leukemia-host interactions and chemotherapy. Therefore, allogeneic sources, i.e. buffy coats (BCs) from health donors and umbilical cord blood (UCB) donations, were exploited for the presence and the expansion of FLT3-ITD-reactive T-cell populations. BC- and UCB-derived CD8+ T cells, were distributed at 105 cells per well on microtiter plates and, were stimulated with antigen-presenting cells (APCs) transfected with in vitro-transcribed mRNA (IVT-mRNA) encoding selected FTL3-ITDs. APCs were autologous CD8- blood mononuclear cells, monocytes or FastDCs.rnrnBuffy coat lymphocytes from 19 healthy individuals were analyzed for CD8+ T-cell reactivity against three immunogenic FLT3-ITDs previously identified in patients VE, IN and QQ and designated as VE_, IN_ and QQ_FLT3-ITD, respectively. These healthy donors carried at least one of the HLA I alleles known to present an ITD-derived peptide from one of these FLT3-ITDs. Reactivities against single ITDs were observed in 8/19 donors. In 4 donors the frequencies of ITD-reactive T cells were determined and were estimated to be in the range of 1.25x10-6 to 2.83x10-7 CD8+ T cells. These frequencies were 1,000- to 10,000-fold lower than the frequency of autologous FLT3-ITD-reactive T cells observed in patient FL. Restricting HLA I molecules were identified in two donors. In one of them, the recognition of VE_FLT3-ITD was found to be restricted by HLA-C*07:02, which is different from the HLA allele restricting the anti-ITD T cells of patient VE. In another donor, the recognition of IN_FLT3-ITD was restricted by HLA-B*35:01, which also had been observed in patient IN (Graf et al., unpublished). By gradual 3´-fragmentation of the IN_FLT3-ITD cDNA, the 10-mer peptide CPSDNEYFYV was identified as the target of allogeneic T cells against IN_FLT3-ITD. rnLymphocytes in umbilical cord blood predominantly exhibit a naïve phenotype. Seven UCB donations were analyzed for T-cell responses against the FLT3-ITDs of patients VE, IN, QQ, JC and FL irrespective of their HLA phenotype. ITD-reactive responses against all stimulatory FLT3-ITDs were observed in 5/7 UCB donations. The frequencies of T cells against single FLT3-ITDs in CD8+ lymphocytes were estimated to be in the range of 1.8x10-5 to 3.6x10-6, which is nearly 15-fold higher than the frequencies observed in BCs. Restricting HLA I molecules were identified in 4 of these 5 positive UCB donations. They were mostly different from those observed in the respective patients. But in one UCB donation T cells against the JC_FLT3-ITD had exactly the same peptide specificity and HLA restriction as seen before in patient JC (Graf et al., 2007). Analyses of UCB responder lymphocytes led to the identification of the 10-mer peptide YESDNEYFYV, encoded by FL_FLT3-ITD, that was recognized in association with the frequent allele HLA-A*02:01. This peptide was able to stimulate and enrich ITD-reactive T cells from UCB lymphocytes in vitro. Peptide responders not only recognized the peptide, but also COS-7 cells co-transfected with FL_FLT3-ITD and HLA-A*02:01.rnrnIn conclusion, T cells against AML- and individual-specific FLT3-ITDs were successfully generated not only from patient-derived blood, but also from allogeneic sources. Thereby, ITD-reactive T cells were detected more readily and at higher frequencies in umbilical cord blood than in buffy coat lymphocytes. It occurred that peptide specificity and HLA restriction of allogeneic, ITD-reactive T cells were identical to autologous patient-derived T cells. As shown herein, allogeneic, FLT3-ITD-reactive T cells can be used for the identification of FLT3-ITD-encoded peptides, e.g. for future therapeutic vaccination studies. In addition, these T cells or their receptors can be applied to adoptive transfer.
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Negli ultimi anni lo spreco alimentare ha assunto un’importanza crescente nel dibattito internazionale, politico ed accademico, nel contesto delle tematiche sulla sostenibilità dei modelli di produzione e consumo, sull’uso efficiente delle risorse e la gestione dei rifiuti. Nei prossimi anni gli Stati Membri dell’Unione Europea saranno chiamati ad adottare specifiche strategie di prevenzione degli sprechi alimentari all’interno di una cornice di riferimento comune. Tale cornice è quella che si va delineando nel corso del progetto Europeo di ricerca “FUSIONS” (7FP) che, nel 2014, ha elaborato un framework di riferimento per la definizione di “food waste” allo scopo di armonizzare le diverse metodologie di quantificazione adottate dai paesi membri. In questo scenario, ai fini della predisposizione di un Piano Nazionale di Prevenzione degli Sprechi Alimentari per l’Italia, il presente lavoro applica per la prima volta il “definitional framework” FUSIONS per l’analisi dei dati e l’identificazione dei principali flussi nei diversi anelli della filiera e svolge un estesa consultazione degli stakeholder (e della letteratura) per identificare le possibili misure di prevenzione e le priorità di azione. I risultati ottenuti evedenziano (tra le altre cose) la necessità di predisporre e promuovere a livello nazionale l’adozione di misure uniformi di quantificazione e reporting; l’importanza del coinvolgimento degli stakeholder nel contesto di una campagna nazionale di prevenzione degli sprechi alimentari; l’esigenza di garantire una adeguata copertura economica per le attività di pianificazione e implementazione delle misure di prevenzione da parte degli enti locali e di un coordinamento a livello nazionale della programmazione regionale; la necessità di una armonizzazione/semplificazione del quadro di riferimento normativo (fiscale, igienico-sanitario, procedurale) che disciplina la donazione delle eccedenze alimentari; l’urgenza di approfondire il fenomeno degli sprechi alimentari attraverso la realizzazione di studi di settore negli stadi a valle della filiera.
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Biobanken sind Sammlungen von Körpersubstanzen, die mit umfangreichen gesundheits- und lebensstilbezogenen sowie geneologischen Daten ihrer Spender verknüpft sind. Sie dienen der Erforschung weit verbreiteter Krankheiten. Diese sog. Volkskrankheiten sind multifaktoriell bedingte Krankheiten. Dies bedeutet, dass diese Krankheiten das Ergebnis eines komplizierten Zusammenspiels von umwelt- und verhaltensrelevanten Faktoren mit individuellen genetischen Prädispositionen sind. Forschungen im Bereich von Pharmakogenomik und Pharmakogenetik untersuchen den Einfluss von Genen und Genexpressionen auf die individuelle Wirksamkeit von Medikamenten sowie auf die Entstehung ungewollter Nebenwirkungen und könnten so den Weg zu einer individualisierten Medizin ebnen. Menschliches Material ist ein wichtiger Bestandteil dieser Forschungen und die Nachfrage nach Sammlungen, die Proben mit Daten verknüpfen, steigt. Einerseits sehen Mediziner in Biobanken eine Chance für die Weiterentwicklung der medizinischen Forschung und des Gesundheitswesens. Andererseits lösen Biobanken auch Ängste und Misstrauen aus. Insbesondere wird befürchtet, dass Proben und Daten unkontrolliert verwendet werden und sensible Bereiche des Persönlichkeitsrechts und der persönlichen Identität betroffen sind. Diese Gefahren und Befürchtungen sind nicht neu, sondern bestanden schon in der Vergangenheit bei jeglicher Form der Spende von Körpersubstanzen. Neu ist aber der Umfang an Informationen, der durch die Genanalyse entsteht und den Spender in ganz besonderer Weise betreffen kann. Bei der Speicherung und Nutzung der medizinischen und genetischen Daten ergibt sich somit ein Spannungsfeld insbesondere zwischen dem Recht der betroffenen Datenspender auf informationelle Selbstbestimmung und den Forschungsinteressen der Datennutzer. Im Kern dreht sich die ethisch-rechtliche Bewertung der Biobanken um die Frage, ob diese Forschung zusätzliche Regeln braucht, und falls ja, wie umfassend diese sein müssten. Im Zentrum dieser Diskussion stehen dabei v.a. ethische Fragen im Zusammenhang mit der informierten Einwilligung, dem Datenschutz, der Wiederverwendung von Proben und Daten, der Information der Spender über Forschungsergebnisse und der Nutzungsrechte an den Daten. Ziel dieser Arbeit ist es, vor dem Hintergrund des Verfassungsrechts, insbesondere dem Recht auf informationelle Selbstbestimmung, das Datenschutzrecht im Hinblick auf die Risiken zu untersuchen, die sich aus der Speicherung, Verarbeitung und Kommunikation von persönlichen genetischen Informationen beim Aufbau von Biobanken ergeben. Daraus ergibt sich die weitere Untersuchung, ob und unter welchen Voraussetzungen die sich entgegenstehenden Interessen und Rechte aus verfassungsrechtlichem Blickwinkel in Einklang zu bringen sind. Eine wesentliche Frage lautet, ob die bisherigen rechtlichen Rahmenbedingungen ausreichen, um den Schutz der gespeicherten höchstpersönlichen Daten und zugleich ihre angemessene Nutzung zu gewährleisten. Das Thema ist interdisziplinär im Schnittfeld von Datenschutz, Verfassungsrecht sowie Rechts- und Medizinethik angelegt. Aus dem Inhalt: Naturwissenschaftliche und empirische Grundlagen von Biobanken – Überblick über Biobankprojekte in Europa und im außereuropäischen Ausland – Rechtsgrundlagen für Biobanken - Recht auf informationelle Selbstbestimmung - Recht auf Nichtwissen - Forschungsfreiheit - Qualitätssicherung und Verfahren – informierte Einwilligung – globale Einwilligung - Datenschutzkonzepte - Forschungsgeheimnis –– Biobankgeheimnis - Biobankgesetz
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Background The goal when resuscitating trauma patients is to achieve adequate tissue perfusion. One parameter of tissue perfusion is tissue oxygen saturation (StO2), as measured by near infrared spectroscopy. Using a commercially available device, we investigated whether clinically relevant blood loss of 500 ml in healthy volunteers can be detected by changes in StO2 after a standardized ischemic event. Methods We performed occlusion of the brachial artery for 3 minutes in 20 healthy female blood donors before and after blood donation. StO2 and total oxygenated tissue hemoglobin (O2Hb) were measured continuously at the thenar eminence. 10 healthy volunteers were assessed in the same way, to examine whether repeated vascular occlusion without blood donation exhibits time dependent effects. Results Blood donation caused a substantial decrease in systolic blood pressure, but did not affect resting StO2 and O2Hb values. No changes were measured in the blood donor group in the reaction to the vascular occlusion test, but in the control group there was an increase in the O2Hb rate of recovery during the reperfusion phase. Conclusion StO2 measured at the thenar eminence seems to be insensitive to blood loss of 500 ml in this setting. Probably blood loss greater than this might lead to detectable changes guiding the treating physician. The exact cut off for detectable changes and the time effect on repeated vascular occlusion tests should be explored further. Until now no such data exist.
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The fusion of mammalian cells into syncytia is a developmental process that is tightly restricted to a limited subset of cells. Besides gamete and placental trophoblast fusion, only macrophages and myogenic stem cells fuse into multinucleated syncytia. In contrast to viral cell fusion, which is mediated by fusogenic glycoproteins that actively merge membranes, mammalian cell fusion is poorly understood at the molecular level. A variety of mammalian transmembrane proteins, among them many of the immunoglobulin superfamily, have been implicated in cell-cell fusion, but none has been shown to actively fuse cells in vitro. Here we report that the FGFRL1 receptor, which is up-regulated during the differentiation of myoblasts into myotubes, fuses cultured cells into large, multinucleated syncytia. We used luciferase and GFP-based reporter assays to confirm cytoplasmic mixing and to identify the fusion inducing domain of FGFRL1. These assays revealed that Ig-like domain III and the transmembrane domain are both necessary and sufficient to rapidly fuse CHO cells into multinucleated syncytia comprising several hundred nuclei. Moreover, FGFRL1 also fused HEK293 and HeLa cells with untransfected CHO cells. Our data show that FGFRL1 is the first mammalian protein that is capable of inducing syncytium formation of heterologous cells in vitro.
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Renal transplantation has become an established option for renal replacement therapy in many patients with end stage renal disease. Living donation is a possibility for timely transplantation, hampered in 20 % of all possible donors and recipients byincompatible blood groups. AB0-incompatible renal transplantation overcomes this hurdle with acceptable allograft survival compared to conventional living-donor renal transplantation. During the last 10 years, the number of patients awaiting renal transplantation older than 65 years has nearly doubled. The decision to transplant those patients and their medical treatment is a growing challenge in transplantation. On the other hand donor age is increasing with potential negative consequences for long-term outcome of organ function. Antibody-mediated humoral rejection have been identified lately as an important cause for allograft failure during long-term follow up of renal transplant patients. New immunological methods to detect donor-specific antibodies, like solid-phase assays (Luminex®), have increased the knowledge and understanding of humoral rejection processes. This will lead hopefully to modified immunosuppressive strategies to minimize organ failure due to chronic rejection.
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Background: In dimorphic seabirds, the larger sex tends to provision more than the smaller sex. In contrast, monogamy and biparental care are often associated with equal effort between the sexes. However, the few studies that have tested sex-specific effort in monomorphic seabirds have primarily examined the details of foraging at sea. Hypotheses: Parental effort is also sex-biased in a monomorphic seabird mating system for one of two reasons: (1) If females enter the period of parental care less able to invest in care due to the cost of egg production, male-biased effort may be necessary to avoid reproductive failure. (2) Alternatively, female-biased effort may occur due to the initial disparity in gamete size, particularly in species with internal fertilization. Organism: Leach’s storm-petrel (Oceanodroma leucorhoa), a monomorphic seabird with true monogamy and obligate biparental care. Site: A breeding colony of Oceanodroma leucorhoa at the Bowdoin Scientific Station on Kent Island, Bay of Fundy, New Brunswick, Canada. Methods: Across multiple breeding seasons, we assessed incubation behaviour and chickrearing behaviour through one manipulative and multiple observational studies. We assessed energetic investment by inducing feather replacement and measuring the resulting rate of feather growth during both the incubation and chick-rearing phases of parental care. Conclusions: We observed male-biased effort. Males incubated the egg for a greater proportion of time than did females and, when faced with an egg that would not hatch, males continued to incubate past the point when females abandoned it. Males made a higher percentage of total food deliveries to chicks than did females, resulting in greater mean daily food provisioning by males than by females. During chick rearing, males grew replacement feathers more slowly than did females, indicating that males were more likely to reduce their own nutritional condition while raising chicks than were females. These results support the hypothesis that females enter the period of parental care at a nutritional deficit and males must compensate to avoid reproductive failure.
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SUMMARY: BACKGROUND: Recruitment of platelets (PLT) during donor PLT apheresis may facilitate the harvest of multiple units within a single donation. METHODS: We compared two PLT apheresis procedures (Amicus and Trima Accel) in a prospective, randomized, paired cross-over study in 60 donors. The 120 donations were compared for depletion of circulating PLT in the donors, PLT yields and PLT recruitment. A recruitment was defined as ratio of total PLT yield and donor PLT depletion > 1. RESULTS: Despite comparable differences of pre- and post-apheresis PLT counts (87 × 10(9)/l in Trima Accel vs. 92 × 10(9)/l in Amicus, p = 0.383), PLT yields were higher with Trima Accel (7.48 × 10(11) vs. 6.06 × 10(11), p < 0.001), corresponding to a higher PLT recruitment (1.90 vs. 1.42, p < 0.001). We observed a different increase of WBC counts after aphereses, which was more pronounced with Trima Accel than with Amicus (1.30 × 10(9)/l vs. 0.46 × 10(9)/l, p < 0.001). CONCLUSION: Both procedures induced PLT recruitment. This was higher in Trima Accel, contributing to a higher yield in spite of a comparable depletion of circulating PLT in the donors. This recruitment facilitates the harvest of multiple units within a single donation and seems to be influenced by the procedure utilized. The different increases of circulating donor white blood cells after donation need further investigation.
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Aim. External fertilisation requires synchronisation of gamete release between the two sexes. Adequate synchronisation is essential in aquatic media because sperm is very short-lived in water. In the cichlid Lamprologus callipterus, fertilisation of the eggs takes place inside an empty snail shell, where females stay inside the shell and males have to ejaculate into the shell opening. This spawning pattern makes the coordination of gamete release difficult. Methods. This study examined the synchronisation of males and females during egg laying. Results. The results showed that the male initiates each spawning sequence and that sperm release and egg laying are very well synchronised. 68% of all sperm releases occurred at exactly the same time when the female laid an egg, and 99% of ejaculations occurred within ±5 seconds from egg deposition. On average 95 eggs are laid one by one with intervals of several minutes between subsequent eggs, leading to a total spawning duration in excess of six hours. Conclusions. We discuss this exceptional spawning pattern and how it might reflect a conflict between the sexes, with males attempting to induce egg laying and females extending the egg laying period to raise the chance for parasitic males to participate in spawning.
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OBJECTIVES: Donation after circulatory declaration of death (DCDD) could significantly improve the number of cardiac grafts for transplantation. Graft evaluation is particularly important in the setting of DCDD given that conditions of cardio-circulatory arrest and warm ischaemia differ, leading to variable tissue injury. The aim of this study was to identify, at the time of heart procurement, means to predict contractile recovery following cardioplegic storage and reperfusion using an isolated rat heart model. Identification of reliable approaches to evaluate cardiac grafts is key in the development of protocols for heart transplantation with DCDD. METHODS: Hearts isolated from anaesthetized male Wistar rats (n = 34) were exposed to various perfusion protocols. To simulate DCDD conditions, rats were exsanguinated and maintained at 37°C for 15-25 min (warm ischaemia). Isolated hearts were perfused with modified Krebs-Henseleit buffer for 10 min (unloaded), arrested with cardioplegia, stored for 3 h at 4°C and then reperfused for 120 min (unloaded for 60 min, then loaded for 60 min). Left ventricular (LV) function was assessed using an intraventricular micro-tip pressure catheter. Statistical significance was determined using the non-parametric Spearman rho correlation analysis. RESULTS: After 120 min of reperfusion, recovery of LV work measured as developed pressure (DP)-heart rate (HR) product ranged from 0 to 15 ± 6.1 mmHg beats min(-1) 10(-3) following warm ischaemia of 15-25 min. Several haemodynamic parameters measured during early, unloaded perfusion at the time of heart procurement, including HR and the peak systolic pressure-HR product, correlated significantly with contractile recovery after cardioplegic storage and 120 min of reperfusion (P < 0.001). Coronary flow, oxygen consumption and lactate dehydrogenase release also correlated significantly with contractile recovery following cardioplegic storage and 120 min of reperfusion (P < 0.05). CONCLUSIONS: Haemodynamic and biochemical parameters measured at the time of organ procurement could serve as predictive indicators of contractile recovery. We believe that evaluation of graft suitability is feasible prior to transplantation with DCDD, and may, consequently, increase donor heart availability.
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Despite the introduction of new immunosuppressive agents, a steady decline of functioning renal allografts after living donation is observed. Thus nonpharmacological strategies to prevent graft loss have to be reconsidered, including donor-specific transfusions (DST). We introduced a cyclosporine-based DST protocol for renal allograft recipients from living-related/unrelated donation. From 1993 to 2003, 200 ml of whole blood, or the respective mononuclear cells from the potential living donor were administered twice to all of our 61 recipient candidates. The transplanted subjects were compared with three groups of patients without DST from the Collaborative Transplant Study (Heidelberg, Germany) during a 6-year period. Six patients were sensitized without delay for a subsequent cadaveric kidney. DST patients had less often treatment for rejection and graft survival was superior compared with subjects from the other Swiss transplant centers (n = 513) or from Western Europe (n = 7024). To diminish the probability that superior results reflect patient selection rather than effects of DST, a 'matched-pair' analysis controlling for relevant factors of transplant outcome was performed. Again, this analysis indicated that recipients with DST had better outcome. Thus, our observation suggests that DST improve the outcome of living kidney transplants even when modern immunosuppressive drugs are prescribed.