Hyperactivity of the IL-23/IL-17 axis is central to plaque psoriasis pathogenesis. Secukinumab, a fully human mAb that selectively inhibits IL-17A, is approved for treatment of psoriasis, psoriatic ...arthritis, and ankylosing spondylitis. Secukinumab improves the complete spectrum of psoriasis manifestations, with durable clinical responses beyond 5 years of treatment. In the feed-forward model of plaque chronicity, IL-17A has been hypothesized as the key driver of pathogenic gene expression by lesional keratinocytes, but in vivo evidence in human subjects is lacking.
We performed a randomized, double-blind, placebo-controlled study (NCT01537432) of patients receiving secukinumab at the clinically approved dose up to 12 weeks. We then correlated plaque and nonlesional skin transcriptomic profiles with histopathologic and clinical measures of efficacy.
After 12 weeks of treatment, secukinumab reversed plaque histopathology in the majority of patients and modulated thousands of transcripts. Suppression of the IL-23/IL-17 axis by secukinumab was evident at week 1 and continued through week 12, including reductions in levels of the upstream cytokine IL-23, the drug target IL-17A, and downstream targets, including β-defensin 2. Suppression of the IL-23/IL-17 axis by secukinumab at week 4 was associated with clinical and histologic responses at week 12. Secukinumab did not affect ex vivo T-cell activation, which is consistent with its favorable long-term safety profile.
Our data suggest that IL-17A is the critical node within the multidimensional pathogenic immune circuits that maintain psoriasis plaques and that early reduction of IL-17A–dependent feed-forward transcripts synthesized by hyperplastic keratinocytes favors plaque resolution.
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Summary
The search for new antifouling (AF) coatings that are environmentally benign has led to renewed interest in the ways that micro‐organisms colonize substrates in the marine environment. This ...review covers recently published research on the global species composition and dynamics of marine biofilms, consisting mainly of bacteria and diatoms found on man‐made surfaces including AF coatings. Marine biofilms directly interact with larger organisms (macrofoulers) during colonization processes; hence, recent literature on understanding the basis of the biofilm/macrofouling interactions is essential and will also be reviewed here. Overall, differences have been identified in species composition between biofilm and planktonic forms for both diatoms and bacteria at various exposure sites. In most studies, the underlying biofilm was found to induce larval and spore settlement of macrofoulers; however, issues such as reproducibility, differences in exposure sites and biofilm composition (natural multispecies vs. monospecific species) may influence the outcomes.
The state-of-the-art in modelling the influence of corrosion damage on the ultimate strength of aged steel-plated maritime platforms is reviewed. This critical review outlines the corrosion ...mechanisms and fundamentals of steel-plated structures in the marine environment. Recent developments in mathematical modelling strategies, in association with in situ thickness measurements, have significantly enhanced the qualitative understanding of the corrosion processes at various locations within marine structures. Based on the corrosion prediction, both experimental and numerical methods have been adopted to realistically assess the ultimate strength of such corroded steel ship structures, in order to ultimately improve the survey and repair strategies.
Steinernema feltiae is a moderately freeze-tolerant entomopathogenic nematode which survives intracellular freezing. We have detected by gas chromatography that infective juveniles of S. feltiae ...produce cryoprotectants in response to cold acclimation and to freezing. Since the survival of this nematode varies with temperature, we analyzed their cryoprotectant profiles under different acclimation and freezing regimes. The principal cryoprotectants detected were trehalose and glycerol with glucose being the minor component. The amount of cryoprotectants varied with the temperature and duration of exposure. Trehalose was accumulated in higher concentrations when nematodes were acclimated at 5°C for two weeks whereas glycerol level decreased from that of the non-acclimated controls. Nematodes were seeded with a small ice crystal and held at -1°C, a regime that does not produce freezing of the nematodes but their bodies lose water to the surrounding ice (cryoprotective dehydration). This increased the levels of both trehalose and glycerol, with glycerol reaching a higher concentration than trehalose. Nematodes frozen at -3°C, a regime that produces freezing of the nematodes and results in intracellular ice formation, had elevated glycerol levels while trehalose levels did not change. Steinernema feltiae thus has two strategies of cryoprotectant accumulation: one is an acclimation response to low temperature when the body fluids are in a cooled or supercooled state and the infective juveniles produce trehalose before freezing. During this process a portion of the glycerol is converted to trehalose. The second strategy is a rapid response to freezing which induces the production of glycerol but trehalose levels do not change. These low molecular weight compounds are surmised to act as cryoprotectants for this species and to play an important role in its freezing tolerance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Of the 132 people known to have been infected with H7N9 influenza viruses in China, 37 died, and many were severely ill. Infection seems to have involved contact with infected poultry. We have ...examined the receptor-binding properties of this H7N9 virus and compared them with those of an avian H7N3 virus. We find that the human H7 virus has significantly higher affinity for α-2,6-linked sialic acid analogues ('human receptor') than avian H7 while retaining the strong binding to α-2,3-linked sialic acid analogues ('avian receptor') characteristic of avian viruses. The human H7 virus does not, therefore, have the preference for human versus avian receptors characteristic of pandemic viruses. X-ray crystallography of the receptor-binding protein, haemagglutinin (HA), in complex with receptor analogues indicates that both human and avian receptors adopt different conformations when bound to human H7 HA than they do when bound to avian H7 HA. Human receptor bound to human H7 HA exits the binding site in a different direction to that seen in complexes formed by HAs from pandemic viruses and from an aerosol-transmissible H5 mutant. The human-receptor-binding properties of human H7 probably arise from the introduction of two bulky hydrophobic residues by the substitutions Gln226Leu and Gly186Val. The former is shared with the 1957 H2 and 1968 H3 pandemic viruses and with the aerosol-transmissible H5 mutant. We conclude that the human H7 virus has acquired some of the receptor-binding characteristics that are typical of pandemic viruses, but its retained preference for avian receptor may restrict its further evolution towards a virus that could transmit efficiently between humans, perhaps by binding to avian-receptor-rich mucins in the human respiratory tract rather than to cellular receptors.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The hemagglutinin (HA) of influenza A(H3N2) virus responsible for the 1968 influenza pandemic derived from an avian virus. On introduction into humans, its receptor binding properties had changed ...from a preference for avian receptors (α2,3-linked sialic acid) to a preference for human receptors (α2,6-linked sialic acid). By 2001, the avidity of human H3 viruses for avian receptors had declined, and since then the affinity for human receptors has also decreased significantly. These changes in receptor binding, which correlate with increased difficulties in virus propagation in vitro and in antigenic analysis, have been assessed by virus hemagglutination of erythrocytes from different species and quantified by measuring virus binding to receptor analogs using surface biolayer interferometry. Crystal structures of HA–receptor analog complexes formed with HAs from viruses isolated in 2004 and 2005 reveal significant differences in the conformation of the 220-loop of HA1, relative to the 1968 structure, resulting in altered interactions between the HA and the receptor analog that explain the changes in receptor affinity. Site-specific mutagenesis shows the HA1 Asp-225→Asn substitution to be the key determinant of the decreased receptor binding in viruses circulating since 2005. Our results indicate that the evolution of human influenza A(H3N2) viruses since 1968 has produced a virus with a low propensity to bind human receptor analogs, and this loss of avidity correlates with the marked reduction in A(H3N2) virus disease impact in the last 10 y.
Wnt proteins transmit myriad intercellular signals crucial for the development and homeostasis of metazoan animals from
Hydra to human. Abnormal Wnt signaling causes a growing number of diseases, ...including cancer and osteoporosis. Depending on the context, a given Wnt signal may denote: cell proliferation or apoptosis; cell fate determination, differentiation, or stem cell maintenance; a variety of changes in cell behavior; and/or coordinated interactions with its neighbors. Which event(s) occur in Wnt-responsive cells depends critically on the ability of Dishevelled (Dsh)/Dvl proteins to interpret distinct types of intracellular, receptor-generated stimuli and transmit them to at least two distinct sets of effector molecules, all while apparently ignoring a third type of Wnt-generated Ca
2+ signal. The three conserved domains present in Dsh/Dvl proteins uniquely function in each Wnt pathway, in part by association with 18 (and counting) Dsh/Dvl-associated proteins. The latest data suggest that Dsh/Dvl proteins organize dynamic, pathway-specific subcellular signaling complexes that ensure correct information routing, signal amplification, and dynamic control through feedback regulation. The biochemical and cell biological mechanisms by which Dsh/Dvl proteins accomplish these remarkable tasks remain obscure.
Auxetics are a modern class of material fabricated by altering the material microstructure. Unlike conventional materials, auxetics exhibit a negative Poisson's ratio when subjected to tensile ...loading. These materials have gained popularity within the research community because of their enhanced properties, such as density, stiffness, fracture toughness and dampening. This paper provides a critical oversight of the auxetic field with particular emphasis to the auxetic foams, due to their low price, easy availability and desirable mechanical properties. Key areas discussed include the fabrication method, the effects played by different parameters (temperature, heating time, cell shape and size and volumetric compression ratio), microstructural models, mechanical properties and potential applications.
In this Feature Article, Critchley et al. introduce the expanding field of auxetic materials and critically review the literature with a primary focus on auxetic foams. Particular attention is given to the fabrication methodologies, the influence played by the fabrication parameters, the microstructural models (both two‐ and three‐dimensional), the mechanical properties and the potential applications of these materials.
A growing body of research supports stromal tumour‐infiltrating lymphocyte (TIL) density in breast cancer to be a robust prognostic and predicive biomarker. The gold standard for stromal TIL ...density quantitation in breast cancer is pathologist visual assessment using haematoxylin and eosin‐stained slides. Artificial intelligence/machine‐learning algorithms are in development to automate the stromal TIL scoring process, and must be validated against a reference standard such as pathologist visual assessment. Visual TIL assessment may suffer from significant interobserver variability. To improve interobserver agreement, regulatory science experts at the US Food and Drug Administration partnered with academic pathologists internationally to create a freely available online continuing medical education (CME) course to train pathologists in assessing breast cancer stromal TILs using an interactive format with expert commentary. Here we describe and provide a user guide to this CME course, whose content was designed to improve pathologist accuracy in scoring breast cancer TILs. We also suggest subsequent steps to translate knowledge into clinical practice with proficiency testing.
Endophentoypes, quantifiable traits lying on the causal chain between a clinical phenotype and etiology, can be used to accelerate genomic discovery in obsessive-compulsive disorder (OCD). Here we ...identify the neuroanatomic changes that are shared by 22 OCD adult and adolescent patients and 25 of their unaffected siblings who are at genetic risk for the disorder. Comparisons were made against 47 age and sex matched healthy controls. We defined the surface morphology of the striatum, globus pallidus and thalamus, and thickness of the cerebral cortex. Patients with OCD show significant surface expansion compared with healthy controls, following adjustment for multiple comparisons, in interconnected regions of the caudate, thalamus and right orbitofrontal cortex. Their unaffected siblings show similar, significant expansion, most marked in the ventromedial caudate bilaterally, the right pulvinar thalamic nucleus and the right orbitofrontal cortex. These regions define a network that has been consistently implicated in OCD. In addition, both patients with OCD and unaffected siblings showed similar increased thickness of the right precuneus, which receives rich input from the thalamic pulvinar nuclei and the left medial temporal cortex. Anatomic change within the orbitofrontostriatal and posterior brain circuitry thus emerges as a promising endophenotype for OCD.