Thymus Extracellular Matrix-Derived Scaffolds Support Graft-Resident Thymopoiesis and Long-Term In Vitro Culture of Adult Thymic Epithelial Cells

The thymus provides the physiological microenvironment critical for the development of T lymphocytes, the cells that orchestrate the adaptive immune system to generate an antigen-specific response. A diverse population of stroma cells provides surface-bound and soluble molecules that orchestrate the intrathymic maturation and selection of developing T cells. Forming an intricate 3D architecture, thymic epithelial cells (TEC) represent the most abundant and important constituent of the thymic stroma. Effective models for in and ex vivo use of adult TEC are still wanting, limiting the engineering of functional thymic organoids and the understanding of the development of a competent immune system. Here a 3D scaffold is developed based on decellularized thymic tissue capable of supporting in vitro and in vivo thymopoiesis by both fetal and adult TEC. For the first time, direct evidences of feasibility for sustained graft-resident T-cell development using adult TEC as input are provided. Moreover, the scaffold supports prolonged in vitro culture of adult TEC, with a retained expression of the master regulator Foxn1. The success of engineering a thymic scaffold that sustains adult TEC function provides unprecedented opportunities to investigate thymus development and physiology and to design and implement novel strategies for thymus replacement therapies

Nogo-B regulates migration and contraction of airway smooth muscle cells by decreasing ARPC 2/3 and increasing MYL-9 expression

<p>Abstract</p> <p>Background</p> <p>Abnormal proliferation, apoptosis, migration and contraction of airway smooth muscle (ASM) cells in airway remodeling in asthma are basically excessive repair responses to a network of inflammatory mediators such as PDGF, but the mechanisms of such responses remain unclear. Nogo-B, a member of the reticulum family 4(RTN4), is known to play a key role in arteriogenesis and tissue repair. Further studies are needed to elucidate the role of Nogo-B in airway smooth muscle abnormalities.</p> <p>Methods</p> <p>A mouse model of chronic asthma was established by repeated OVA inhalation and subjected to Nogo-B expression analysis using immunohistochemistry and Western Blotting. Then, primary human bronchial smooth muscle cells (HBSMCs) were cultured <it>in vitro </it>and a siRNA interference was performed to knockdown the expression of Nogo-B in the cells. The effects of Nogo-B inhibition on PDGF-induced HBSMCs proliferation, migration and contraction were evaluated. Finally, a proteomic analysis was conducted to unveil the underlying mechanisms responsible for the function of Nogo-B.</p> <p>Results</p> <p>Total Nogo-B expression was approximately 3.08-fold lower in chronic asthmatic mice compared to naïve mice, which was obvious in the smooth muscle layer of the airways. Interference of Nogo-B expression by siRNA resulted nearly 96% reduction in mRNA in cultured HBSMCs. In addition, knockdown of Nogo-B using specific siRNA significantly decreased PDGF-induced migration of HBSMCs by 2.3-fold, and increased the cellular contraction by 16% compared to negative controls, but had limited effects on PDGF-induced proliferation. Furthermore, using proteomic analysis, we demonstrate that the expression of actin related protein 2/3 complex subunit 5 (ARPC 2/3) decreased and, myosin regulatory light chain 9 isoform a (MYL-9) increased after Nogo-B knockdown.</p> <p>Conclusions</p> <p>These data define a novel role for Nogo-B in airway remodeling in chronic asthma. Endogenous Nogo-B, which may exert its effects through ARPC 2/3 and MYL-9, is necessary for the migration and contraction of airway smooth muscle cells.</p

Improvement of primary care for patients with chronic heart failure: A study protocol for a cluster randomised trial comparing two strategies

<p>Abstract</p> <p>Background</p> <p>Many patients with chronic heart failure (CHF), a common condition with high morbidity and mortality rates, receive treatment in primary care. To improve the management of CHF in primary care, we developed an implementation programme comprised of educational and organisational components, with support by a practice visitor and focus both on drug treatment and lifestyle advice, and on organisation of care within the practice and collaboration with other healthcare providers. Tailoring has been shown to improve the success of implementation programmes, but little is known about what would be best methods for tailoring, specifically with respect to CHF in primary care.</p> <p>Methods/design</p> <p>We describe the study protocol of a cluster randomised controlled trial to examine the effectiveness of tailoring a CHF implementation programme to general practices compared to a standardised way of delivering a programme. The study population will consist of 60 general practitioners (GPs) and the CHF patients they include. GPs are randomised in blocks of four, stratified according to practice size. With a tailored implementation programme GPs prioritise the issues that will form the bases of the support for the practice visits. These may comprise several issues, both educational and organizational.</p> <p>The primary outcome measures are patient's experience of receiving structured primary care for CHF (PACIC, a questionnaire related to the Chronic Care Model), patients' health-related utilities (EQ-5D), and drugs prescriptions using the guideline adherence index. Patients being clustered in practices, multilevel regression analyses will be used to explore the effect of practice size and type of intervention programme. In addition we will examine both changes within groups and differences at follow-up between groups with respect to drug dosages and advice on lifestyle issues. Furthermore, in interviews the feasibility of the programme and goal attainment, organisational changes in CHF care, and formalised cooperation with other disciplines will be assessed.</p> <p>Discussion</p> <p>In the tailoring of the programme we will present the GPs a list with barriers; GPs will assess relevance and possibility to solve these barriers. The list is rigorously developed and tested in various projects. The factors for ordering the barriers are related to the innovation, the healthcare professional, the patient, and the context.</p> <p>CHF patients do not form a homogeneous group. Subgroup analyses will be performed based on the distinction between systolic CHF and CHF with preserved left ventricular function (diastolic CHF).</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN18812755">ISRCTN18812755</a></p

Same patient, new stone composition: amprenavir urinary stone

We report here the first case to add amprenavir to the growing list of antiretroviral drugs associated with urinary stones. The first reported case of a nelfinavir urinary stone was reported in 2002 in a 37-year-old HIV-infected woman. In September 2007, the same female patient was referred to our department with recent onset of right flank pain and recurrent urinary tract infections. Abdominal computed tomography revealed three obstructing stones in the distal right ureter, another stone in the right renal pelvis with hydronephrosis and a stone in the left kidney. After stone retrieval, analysis of the stone by liquid chromatography with mass spectrometry revealed a stone composition of 95% unmodified amprenavir and 5% ritonavir

Identification of a receptor necessary for Nogo-B stimulated chemotaxis and morphogenesis of endothelial cells

Nogo isoforms (Nogo-A and -B) have been implicated in regulating neural and cardiovascular functions, such as cell spreading and chemotaxis. Unlike the loop domain (Nogo-66) found in all Nogo isoforms that can interact with a neural-specific Nogo-66 receptor, the receptor for the amino terminus of Nogo-B that mediates vascular function is unknown. Here, we identify a previously uncharacterized Nogo-B receptor specific for the amino terminus of Nogo-B and show that Nogo-B receptor localizes with the ligand Nogo-B during VEGF and wound healing angiogenesis in vivo, mediates chemotaxis in a heterologous expression system and chemotaxis, and 3D tube formation in native endothelial cells. Thus, identification of this receptor may lead to the discovery of agonists or antagonists of this pathway to regulate vascular remodeling and angiogenesis