72 research outputs found

    Role of zinc in dendritic cell activation and the regulation of complement protein interactions

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    The importance of zinc in immune system is complex and recognised mostly by the effects of zinc deficiency which affects both innate and adaptive immunity. The results presented here provided insight into the complex role of zinc in immunity through examination of the roles of zinc in dendritic cell activation and regulation of complement protein interactions. Little is known about the mechanism by which zinc affects immune cell function. Here we show that Toll-like receptor 4 signalling upon lipopolysaccharide (LPS) binding, alters the expression of zinc transporters, to maintain the stable intracellular free zinc. This indicates the importance of zinc on every level of dendritic cells (DCs) maturation, beginning with antigen recognition, through antigen processing and cell migration to the lymphatic organs, to finally antigen presentation to T-cells. Hydroxyapatite along with LPS can trigger DCs maturation. Following this finding we presented a global picture of proteomic changes that occur in maturing DCs, which was characterised by reduced expression of proteins that drive cellular processes including metabolism and protein translation. Proteomic results may also change the current understanding of antigen presentation by DCs, implicating major histocompatibility complex (MHC) class I in “delayed” antigen presentation. Zinc is also crucial in innate immunity as it inhibits the interaction of complement proteins C1q, Factor H and C3 with histidine rich glycoprotein (HRG). The results suggest for the first time, that binding of complement proteins to HRG is not solely dependent on the N-terminus. Also the role of zinc in the early onset of diseases related to tissue calcification was examined, showing its enhancing effect on HRG binding to hydroxyapatite

    Zero-Broadening Measurement in Brillouin Based Slow-Light Delays

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    A novel method for the achievement of zero-broadening in a SBS based slow-light system is discussed in theory and demonstrated experimentally. The system is realized just with a single broadened Brillouin gain. It is shown, that if the gain bandwidth is much broader than the initial pulse width, the output pulse width decreases with increasing pump power. A compression of approximately 90 % of the initial pulse width was achieved in simulation and experiment

    Developing and assessing the feasibility of a home-based preexposure prophylaxis monitoring and support program

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    We piloted PrEP@Home, a preexposure prophylaxis system of remote laboratory and behavioral monitoring designed to replace routine quarterly follow-up visits with home care to reduce the patient and provider burden. The system was highly acceptable and in-demand for future use, and more than one-third of participants reported greater likelihood of persisting in care if available

    Quantitative proteomic changes in LPS-activated monocyte-derived dendritic cells : a SWATH-MS study

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    We would like to thank Fiona Cooke for her help with collection of blood samples. We wish to thank the Wellcome Trust for funding the purchase of the TripleTOF 5600+ mass spectrometer (grant number 094476/Z/10/Z) and their Institutional Strategic Support Fund (grant number 097831/Z/11/Z) for funding a PhD studentship (to D.W.-M.). This work was also supported by Arthritis Research UK (grant number 21261).Dendritic cells are key immune cells that respond to pathogens and co-ordinate many innate and adaptive immune responses. Quantitative mass spectrometry using Sequential Window Acquisition of all THeoretical fragment-ion spectra-Mass Spectrometry (SWATH-MS) was performed here to determine the global alterations in monocyte-derived dendritic cells (moDCs) in response to stimulation with lipopolysaccharide (LPS). A moDC library of 4,666 proteins was generated and proteins were quantified at 0, 6 and 24 h post-LPS stimulation using SWATH-MS. At 6 h and 24 h post-LPS exposure, the relative abundance of 227 and 282 proteins was statistically significantly altered (p-value≤0.05), respectively. Functional annotation of proteins exhibiting significant changes in expression between the various time points led to the identification of clusters of proteins implicated in distinct cellular processes including interferon and interleukin signalling, endocytosis, the ER-phagosome pathway and antigen-presentation. Major histocompatibility complex (MHC) class I proteins were highly upregulated at 24 h, in SWATH-MS, whilst MHC class II proteins exhibited comparatively less change over this period. This study provides new detailed insight into the global proteomic changes that occur in moDCs during antigen processing and presentation and further demonstrates the potential of SWATH-MS for the quantitative study of proteins involved in cellular processes.Publisher PDFPeer reviewe

    On the origin of proteins in human drusen : the meet, greet and stick hypothesis

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    This research was part-supported by de Algemene Nederlandse Vereniging ter Voorkoming van Blindheid (ANVVB), de Stichting Blinden-Penning, de Gelderse Blinden Stichting, de Landelijke Stichting voor Blinden en Slechtzienden (LSBS), Stichting Oogfonds Nederland, Stichting MD Fonds and Stichting Retina Nederland Fonds (represented by Uitzicht, grants 2011-6 and 2014-7 to A.A.B.), de Rotterdamse Stichting Blindenbelangen (RSB), de Haagse Stichting Blindenhulp, Stichting Lijf en Leven, Stichting voor Ooglijders (to A.A.B.); ZonMW grant nr 446001002 (to A.A.B. and C.K.); the Bill Brown Charitable Trust, Moorfields Eye Hospital Special Trustees, Mercer Fund from Fight for Sight, the Eye-Risk project funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 634479 (I.L. and E.E.), Fight for Sight project grant (I.L. and A.S.), the Bright Focus Foundation grant nr M2015370 (to SMH).Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplement the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These “drusenomics” studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may “meet, greet and stick” to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.PostprintPeer reviewe

    HIV Prevention Via Mobile Messaging for Men Who Have Sex With Men (M-Cubed): Protocol for a Randomized Controlled Trial

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    Background: Men who have sex with men (MSM) continue to be the predominately impacted risk group in the United States HIV epidemic and are a priority group for risk reduction in national strategic goals for HIV prevention. Modeling studies have demonstrated that a comprehensive package of status-tailored HIV prevention and care interventions have the potential to substantially reduce new infections among MSM. However, uptake of basic prevention services, including HIV testing, sexually transmitted infection (STI) testing, condom distribution, condom-compatible lubricant distribution, and preexposure prophylaxis (PrEP), is suboptimal. Further, stronger public health strategies are needed to promote engagement in HIV care and viral load suppression among MSM living with HIV. Mobile health (mHealth) tools can help inform and encourage MSM regarding HIV prevention, care, and treatment, especially among men who lack access to conventional medical services. This protocol details the design and procedures of a randomized controlled trial (RCT) of a novel mHealth intervention that comprises a comprehensive HIV prevention app and brief, tailored text- and video-based messages that are systematically presented to participants based on the participants’ HIV status and level of HIV acquisition risk. Objective: The objective of the RCT was to test the efficacy of the Mobile Messaging for Men (M-Cubed, or M3) app among at least 1200 MSM in Atlanta, Detroit, and New York. The goal was to determine its ability to increase HIV testing (HIV-negative men), STI testing (all men), condom use for anal sex (all men), evaluation for PrEP eligibility, uptake of PrEP (higher risk HIV-negative men), engagement in HIV care (men living with HIV), and uptake of and adherence to antiretroviral medications (men living with HIV). A unique benefit of this approach is the HIV serostatus-inclusiveness of the intervention, which includes both HIV-negative and HIV-positive MSM. Methods: MSM were recruited through online and venue-based approaches in Atlanta, Detroit, and New York City. Men who were eligible and consented were randomized to the intervention (immediate access to the M3 app for a period of three months) or to the waitlist-control (delayed access) group. Outcomes were evaluated immediately post intervention or control period, and again three and six months after the intervention period. Main outcomes will be reported as period prevalence ratios or hazards,depending on the outcome. Where appropriate, serostatus/risk-specific outcomes will be evaluated in relevant subgroups. Men randomized to the control condition were offered the opportunity to use (and evaluate) the M3 app for a three-month period after the final RCT outcome assessment. Results: M3 enrollment began in January 2018 and concluded in November 2018. A total of 1229 MSM were enrolled. Datacollection was completed in September 2019.Conclusions: This RCT of the M3 mobile app seeks to determine the effects of an HIV serostatus–inclusive intervention on the use of multiple HIV prevention and care-related outcomes among MSM. A strength of the design is that it incorporates a large sample and broad range of MSM with differing prevention needs in three cities with high prevalence of HIV among MSM

    Investigation of the properties and applications of the saturated stimulated Brillouin scattering

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    Es ist wohl gerade die Einfachheit seiner Erzeugung, welche den nichtlinearen optischen Effekt der stimulierten Brillouin-Streuung so interessant für viele Anwendungen in der optischen Signalverarbeitung, der Fasersensorik, der hochauflösenden Spektroskopie und auch der Signalverzögerung und -speicherung macht. Die geringe Verstärkungsbandbreite kann zur selektiven Filterung oder Abtastung optischer Signale eingesetzt werden, was die Grundlage der optischen Spektroskopie aber auch der Lichtspeicherung ist. Darüber hinaus werden Signale innerhalb dieser Bandbreite nicht nur verstärkt, sondern auch abhängig vom Gewinn bzw. der eingestellten Pumpleistung verzögert. Diese Eigenschaft ist die Grundlage der sogenannten Slow-Light-Systeme. Damit kann mit einem Brillouin-Verstärker ein durchstimmbarer optischer Kurzzeitpuffer realisiert werden. In der vorliegenden Arbeit werden mit Hilfe gezielt gesättigter Brillouin-Verstärker grundlegende Beschränkungen des Brillouin-basierten Slow-Light und der Brillouin-basierten optischen Filterung aufgehoben, was mit den herkömmlichen linearen Ansätzen nicht möglich ist. Der Vorteil der Sättigung des Brillouin-Verstärkers ist, dass sie nur zu einer vorhersagbaren Begrenzung des Amplitudenspektrums aber nicht zur Entstehung neuer Signalfrequenzen führt. Die spektrale Begrenzung des verstärkten Signals und ein nichtlinearer Verlauf der Gruppenlaufzeit im spektralen Randbereich des Brillouin-Verstärkers führen zu einer zeitlichen Verbreiterung der verzögerten Lichtpulse. Diese Verbreiterung ist insofern problematisch, dass sie die Unterscheidbarkeit der verschiedenen Signalpegel für logische Einsen und Nullen signifikant verschlechtert. Mit Hilfe des vorgestellten gesättigten Systems erfolgt eine gezielte Rückformung der verzögerten Pulse, was erstmalig zu einer verbreiterungsfreien und damit auch verlustarmen Pulsspeicherung führt. Darüber hinaus kann auf Basis der Nachbildung der gesättigten Filtercharakteristik mit einem linearen Brillouin-Verstärker ebenfalls eine verbreiterungsfreie Pulsverzögerung nachgewiesen werden. Ein optischer Speicher kann aber auch durch Unterabtastung eines Signalspektrums mit einem Brillouin-basierten Kammfilter realisiert werden. Die maximale Speicherzeit ist dabei durch die natürliche Brillouin Gewinnbandbreite begrenzt. Dieser Wert ist abhängig von der Pump- und Signalleistung, der Umgebungstemperatur, von mechanischem Stress und vom Fasermaterial. Unter Ausnutzung der Sättigungseigenschaften des Brillouin-Gewinns lässt sich die Gewinnbandbreite durch Überlagerung einer sättigenden Spektralblende nahezu beliebig verkleinern. In dieser Arbeit wird auf Basis dieser Methode eine Bandbreitenreduktion des Brillouin-Filters um etwa eine Größenordnung nachgewiesen, wobei das Potential zur Verringerung um mehrere Größenordnungen besteht.It is probably the simplicity of its generation, which makes the nonlinear optical effect of stimulated Brillouin scattering that interesting for a lot of applications, such as optical signal processing, fiber sensorics, high-resolution optical spectroscopy, optical buffering and storage. Its small amplification bandwidth can be used for selective filtering or sampling of optical signals, which is the basis of optical spectroscopy and light storage as well. Furthermore, inside this bandwidth signals are not just amplified. They are delayed as well, depending on the gain and the pump power, respectively. This attribute is the foundation of the so-called slow-light systems. Therefore, a Brillouin amplifier can also be used used to implement a tunable optical short-time buffer. In this thesis it is shown that the saturation of the Brillouin amplifier can be applied to Brillouin based slow-light and Brillouin based optical filtering to remove their inherent limitations, which is impossible to do with the Brillouin amplifier working in the linear regime. The advantage of the saturation of a Brillouin amplifier is that it leads to a predictable limitation of the amplitude spectrum of the amplified signal, but not to the generation of new signal frequencies. The spectral narrowing of the amplified Signal and the nonlinear group delay at the spectral edges of the Brillouin amplifier cause a distortion of the delayed light pulses, which is primarily expressed in a temporal broadening of the pulse. Since it impairs the distinctiveness of the different signal levels for logical ones and zeros, this broadening is critically to the application of the method. With the help of the proposed saturated system the optical pulse is reshaped to its initial values. For the first time, this leads to a zero-broadening optical buffering of the pulses. Furthermore, it is shown that the reshaping method and its filtering characteristics can be reproduced by a Brillouin amplifier operating in the linear regime to achieve zero-broadening optical pulse delay as well. Optical storage can also be realized by subsampling the signal spectrum with a Brillouin based comb filter. The maximum storage time there is limited by the natural Brillouin gain bandwidth. This value depends on the pump and signal power, the temperature of the environment, mechanical strain and the fiber material. The superposition of a saturating frequency domain aperture to the signal of interest can be used to reduce the Brillouin gain bandwidth to almost any value. The Brillouin gain is supposed to be saturated in the spectral region of the aperture and it is not affected inside the aperture's gap. Based on this method, a bandwidth reduction of approximately one order of magnitude is proven experimentally. But, there could be a theoretical potential to reduce the gain bandwidth by several orders of magnitude

    Woman and marriage - the preparation for the role of a wife in the face of handbooks, the press and recollections at the turn of XIX and XX centuries.

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    The theme of my work is the preparation women for the role of wife based on the handbooks, newspapers and recollections from the late nineteenth and early twentieth century. My work consists of three chapters. The first chapter shows preparing a young girl for the role of wife, which have began already in childhood and was continued during the adolescence, when the issue of sex education was also appeared. On the basis of the sources I present the desired look and traits of character a prospective wife – to-be should have. I also try to answer the question how the spinsterhood was perceived at that time, and whether it was a significant problem and if there were any rules for the selection of marriage. The second chapter takes us to the carnival period, accompanied by endless balls that were a perfect opportunity to find the other half. Who determined the choice of partners? What was the courtship? In the second chapter I will try to give answers to these questions. In the last chapter I will try to find out why the relationship very often turned out to be disappointing. What were the sources of this problem? and whether there were some alternatives such as divorce or the woman had to be stuck in an unhappy relationship?Tematem mojej pracy jest przygotowanie kobiety do roli żony w oparciu o poradniki, prasę i wspomnienia pochodzące z przełomu XIX i XX wieku Moja praca składa się z trzech rozdziałów. Celem pierwszego jest pokazanie przygotowań młodej dziewczyny do roli żony, które rozpoczynało się już w okresie dzieciństwa i było kontynuowane podczas dojrzewania, kiedy to pojawia się też kwestia wychowania seksualnego. Bazując na źródłach przedstawiam jak powinna była wyglądać oraz jakie cechy charakteru posiadać idealna kandydatka na żonę. Staram się też odpowiedzieć na pytanie jak postrzegano w ówczesnych czasach staropanieństwo i czy był to znaczący problem a także czy istniały jakieś reguły doboru małżeńskiego. Drugi rozdział przenosi nas w okres karnawału, któremu towarzyszą niekończące się bale będące doskonałą okazją znalezienia drugiej połówki. Jeśli jednak szczęście tu nie dopisało to czy były jeszcze inne możliwości zapoznania się? Kto decydował o wyborze partnerów? Jak wyglądał okres narzeczeństwa? W drugim rozdziale będę starała się dać odpowiedzi na te pytania. W ostatnim rozdziale spróbuję dowiedzieć się dlaczego związek bardzo często okazywał się rozczarowaniem a małżeńska rzeczywistość daleka od, wpajanego od dzieciństwa, ideału. Jakie były tego źródła i czy w razie niepowodzeń istniały alternatywne rozwiązania takie jak np. rozwód czy też kobieta musiała tkwić w nieszczęśliwym związku
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