Bench-to-bedside review: The role of glycosaminoglycans in respiratory disease.

The extracellular matrix (ECM) plays a significant role in the mechanical behaviour of the lung parenchyma. The ECM is composed of a three-dimensional fibre mesh that is filled with various macromolecules, among which are the glycosaminoglycans (GAGs). GAGs are long, linear and highly charged heterogeneous polysaccharides that are composed of a variable number of repeating disaccharide units. There are two main types of GAGs: nonsulphated GAG (hyaluronic acid) and sulphated GAGs (heparan sulphate and heparin, chondroitin sulphate, dermatan sulphate, and keratan sulphate). With the exception of hyaluronic acid, GAGs are usually covalently attached to a protein core, forming an overall structure that is referred to as proteoglycan. In the lungs, GAGs are distributed in the interstitium, in the sub-epithelial tissue and bronchial walls, and in airway secretions. GAGs have important functions in lung ECM: they regulate hydration and water homeostasis; they maintain structure and function; they modulate the inflammatory response; and they influence tissue repair and remodelling. Given the great diversity of GAG structures and the evidence that GAGs may have a protective effect against injury in various respiratory diseases, an understanding of changes in GAG expression that occur in disease may lead to opportunities to develop innovative and selective therapies in the future

Visualizing the microscopic coexistence of spin density wave and superconductivity in underdoped NaFe1-xCoxAs

Although the origin of high temperature superconductivity in the iron pnictides is still under debate, it is widely believed that magnetic interactions or fluctuations play an important role in triggering Cooper pairing. Because of the relevance of magnetism to pairing, the question of whether long range spin magnetic order can coexist with superconductivity microscopically has attracted strong interests. The available experimental methods used to answer this question are either bulk probes or local ones without control of probing position, thus the answers range from mutual exclusion to homogeneous coexistence. To definitively answer this question, here we use scanning tunneling microscopy to investigate the local electronic structure of an underdoped NaFe1-xCoxAs near the spin density wave (SDW) and superconducting (SC) phase boundary. Spatially resolved spectroscopy directly reveal both the SDW and SC gap features at the same atomic location, providing compelling evidence for the microscopic coexistence of the two phases. The strengths of the SDW and SC features are shown to anti correlate with each other, indicating the competition of the two orders. The microscopic coexistence clearly indicates that Cooper pairing occurs when portions of the Fermi surface (FS) are already gapped by the SDW order. The regime TC < T < TSDW thus show a strong resemblance to the pseudogap phase of the cuprates where growing experimental evidences suggest a FS reconstruction due to certain density wave order. In this phase of the pnictides, the residual FS has a favorable topology for magnetically mediated pairing when the ordering moment of the SDW is small.Comment: 18 pages, 4 figure

implications for first line treatment recommendations

Introduction: Treatment for All recommendations have allowed access to antiretroviral (ARV) treatment for an increasing number of patients. This minimizes the transmission of infection but can potentiate the risk of transmitted (TDR) and acquired drug resistance (ADR). Objective: To study the trends of TDR and ADR in patients followed up in Portuguese hospitals between 2001 and 2017. Methods: In total, 11,911 patients of the Portuguese REGA database were included. TDR was defined as the presence of one or more surveillance drug resistance mutation according to the WHO surveillance list. Genotypic resistance to ARV was evaluated with Stanford HIVdb v7.0. Patterns of TDR, ADR and the prevalence of mutations over time were analyzed using logistic regression. Results and Discussion: The prevalence of TDR increased from 7.9% in 2003 to 13.1% in 2017 (p < 0.001). This was due to a significant increase in both resistance to nucleotide reverse transcriptase inhibitors (NRTIs) and non-nucleotide reverse transcriptase inhibitors (NNRTIs), from 5.6% to 6.7% (p = 0.002) and 2.9% to 8.9% (p < 0.001), respectively. TDR was associated with infection with subtype B, and with lower viral load levels (p < 0.05). The prevalence of ADR declined from 86.6% in 2001 to 51.0% in 2017 (p < 0.001), caused by decreasing drug resistance to all antiretroviral (ARV) classes (p < 0.001). Conclusions: While ADR has been decreasing since 2001, TDR has been increasing, reaching a value of 13.1% by the end of 2017. It is urgently necessary to develop public health programs to monitor the levels and patterns of TDR in newly diagnosed patients.publishersversionpublishe

Uncertainties in projecting climate-change impacts in marine ecosystems

Projections of the impacts of climate change on marine ecosystems are a key prerequisite for the planning of adaptation strategies, yet theyare inevitablyassociated withuncertainty.Identifying,quantifying,andcommunicatingthisuncertaintyis keytobothevaluatingtherisk associated with a projection and building confidence in its robustness. Wereview howuncertainties in such projections are handled in marine science. We employan approach developedin climatemodelling by breaking uncertainty down into(i) structural (model) uncertainty,(ii) initialization and internalvariabilityuncertainty,(iii)parametricuncertainty,and(iv)scenariouncertainty.Foreachuncertaintytype,wethenexaminethecurrent state-of-the-art in assessing and quantifying its relative importance. We consider whether the marine scientific community has addressed these types of uncertainty sufficiently and highlight the opportunities and challenges associated with doing a better job. We find that even within a relatively small field such as marine science, there are substantial differences between subdisciplines in the degree of attention given to each type of uncertainty. We find that initialization uncertainty is rarely treated explicitly and reducing this type of uncertainty may deliver gainsontheseasonal-to-decadaltime-scale.Weconcludethatallpartsofmarinesciencecouldbenefitfromagreaterexchangeofideas,particularly concerningsuchauniversalproblemsuchasthetreatmentofuncertainty.Finally,marinescienceshouldstrivetoreachthepointwherescenario uncertainty is the dominant uncertainty in our projections

Lymphotoxin-β receptor in microenvironmental cells promotes the development of T-cell acute lymphoblastic leukaemia with cortical/mature immunophenotype.

Lymphotoxin-mediated activation of the lymphotoxin-β receptor (LTβR; LTBR) has been implicated in cancer, but its role in T-cell acute lymphoblastic leukaemia (T-ALL) has remained elusive. Here we show that the genes encoding lymphotoxin (LT)-α and LTβ (LTA, LTB) are expressed in T-ALL patient samples, mostly of the TAL/LMO molecular subtype, and in the TEL-JAK2 transgenic mouse model of cortical/mature T-ALL (Lta, Ltb). In these mice, expression of Lta and Ltb is elevated in early stage T-ALL. Surface LTα1 β2 protein is expressed in primary mouse T-ALL cells, but only in the absence of microenvironmental LTβR interaction. Indeed, surface LT expression is suppressed in leukaemic cells contacting Ltbr-expressing but not Ltbr-deficient stromal cells, both in vitro and in vivo, thus indicating that dynamic surface LT expression in leukaemic cells depends on interaction with its receptor. Supporting the notion that LT signalling plays a role in T-ALL, inactivation of Ltbr results in a significant delay in TEL-JAK2-induced leukaemia onset. Moreover, young asymptomatic TEL-JAK2;Ltbr(-/-) mice present markedly less leukaemic thymocytes than age-matched TEL-JAK2;Ltbr(+/+) mice and interference with LTβR function at this early stage delayed T-ALL development. We conclude that LT expression by T-ALL cells activates LTβR signalling in thymic stromal cells, thus promoting leukaemogenesis.Grants from Fundação para a Ciencia e a Tecnologia (PTDC/SAU-OBD/103336/2008 and PEst-OE/EQB/LA0023/2013), Nucleo Regional Sul da Liga Portuguesa Contra o Cancro (NRS/LPCC-Terry Fox) and Fundacao MSD to NRdS; grants from the Sao Paulo Research Foundation (FAPESP 08/10034-1 and 12/12802-1) to JAY; and Plan Cancer Action 29 to ED. MTF (SFRH/BD/75137/2010) MNG (SFRH/BD/80503/2011), and RKK (SFRH/BPD/70718/2010) were recipients of FCT PhD or postdoctoral fellowships. ABS and JAY are supported by PhD and Productivity Fellowships, respectively, from the Brazilian National Council for Scientific and Technological Development (CNPq). NRdS has been supported by FCT Ciencia 2007 and FCT Investigator contracts (IF/00056/2012)